FINAL OFFICE ACTION
This application has been assigned or remains assigned to Technology Center 1700, Art Unit 1774 and the following will apply for this application:
Please direct all written correspondence with the correct application serial number for this application to Art Unit 1774.
Telephone inquiries regarding this application should be directed to the Electronic Business Center (EBC) at http://www.uspto.gov/ebc/index.html or 1-866-217-9197 or to the Examiner at (571) 272-1139. All official facsimiles should be transmitted to the centralized fax receiving number (571)-273-8300.
Notice of Pre-AIA or AIA Status
The present application, filed on or after March 16, 2013, is being examined under the first inventor to file provisions of the AIA .
Election/Restriction Requirement
Applicant’s election without traverse of Group II in the reply filed on 7 JUN 2024 is acknowledged.
Claims 1-5, 9, 15-17, 19, 21, 24, 26, and 29 are thereby withdrawn from further consideration pursuant to 37 CFR 1.142(b) as being drawn to a nonelected invention, there being no allowable generic or linking claim. Election was made without traverse in the reply filed on 7 JUN 2024.
Priority
Acknowledgment is made of applicant's claim for domestic priority under 35 U.S.C. § 119(e).
Information Disclosure Statement
Note the attached PTO-1449 forms submitted with the Information Disclosure Statements.
Drawings
The drawing sheet filed 25 OCT 2025 is approved.
Specification
The abstract is acceptable.
The title is acceptable.
Claim Rejections - 35 USC § 103
The terms used in this respect are given their broadest reasonable interpretation in their ordinary usage in context as they would be understood by one of ordinary skill in the art, in light of the written description in the specification, including the drawings, without reading into the claim any disclosed limitation or particular embodiment. See, e.g., In re Am. Acad. of Sci. Tech. Ctr., 367 F.3d 1359, 1364 (Fed. Cir. 2004); In re Hyatt, 211 F.3d 1367, 1372 (Fed. Cir. 2000); In re Morris, 127 F.3d 1048, 1054-55 (Fed. Cir. 1997); In re Zletz, 893 F.2d 319, 321-22 (Fed. Cir. 1989). The Examiner interprets claims as broadly as reasonable in view of the specification, but does not read limitations from the specification into a claim. Elekta Instr. S.A.v.O.U.R. Sci. Int'l, Inc., 214 F.3d 1302, 1307 (Fed. Cir. 2000).
To determine whether subject matter would have been obvious, "the scope and content of the prior art are to be determined; differences between the prior art and the claims at issue are to be ascertained; and the level of ordinary skill in the pertinent art resolved .... Such secondary considerations as commercial success, long felt but unsolved needs, failure of others, etc., might be utilized to give light to the circumstances surrounding the origin of the subject matter sought to be patented." Graham v. John Deere Co. of Kansas City, 383 U.S. 1, 17-18 (1966).
The Supreme Court has noted:
Often, it will be necessary for a court to look to interrelated teachings of multiple patents; the effects of demands known to the design community or present in the marketplace; and the background knowledge possessed by a person having ordinary skill in the art, all in order to determine whether there was an apparent reason to combine the known elements in the fashion claimed by the patent at issue.
KSR Int'l Co. v. Teleflex Inc., 127 S.Ct. 1727, 1740-41 (2007). "Under the correct analysis, any need or problem known in the field of endeavor at the time of invention and addressed by the patent can provide a reason for combining the elements in the manner claimed." (Id. at 1742).
In the event the determination of the status of the application as subject to AIA 35 U.S.C. 102 and 103 (or as subject to pre-AIA 35 U.S.C. 102 and 103) is incorrect, any correction of the statutory basis for the rejection will not be considered a new ground of rejection if the prior art relied upon, and the rationale supporting the rejection, would be the same under either status.
The following is a quotation of 35 U.S.C. 103 which forms the basis for all obviousness rejections set forth in this Office action:
A patent for a claimed invention may not be obtained, notwithstanding that the claimed invention is not identically disclosed as set forth in section 102, if the differences between the claimed invention and the prior art are such that the claimed invention as a whole would have been obvious before the effective filing date of the claimed invention to a person having ordinary skill in the art to which the claimed invention pertains. Patentability shall not be negated by the manner in which the invention was made.
This application currently names joint inventors. In considering patentability of the claims the examiner presumes that the subject matter of the various claims was commonly owned as of the effective filing date of the claimed invention(s) absent any evidence to the contrary. Applicant is advised of the obligation under 37 CFR 1.56 to point out the inventor and effective filing dates of each claim that was not commonly owned as of the effective filing date of the later invention in order for the examiner to consider the applicability of 35 U.S.C. 102(b)(2)(C) for any potential 35 U.S.C. 102(a)(2) prior art against the later invention.
The instant office action conforms to the policies articulated in the Federal Register notice titled “Updated Guidance for Making a Proper Determination of Obviousness” at 89 Fed. Reg. 14449, February 27, 2024, wherein the Supreme Court’s directive to employ a flexible approach to understanding the scope of prior art is reflected in the frequently quoted sentence, ‘‘A person of ordinary skill is also a person of ordinary creativity, not an automaton.’’ Id. at 421, 127 S. Ct. at 1742. In this section of the KSR decision, the Supreme Court instructed the Federal Circuit that persons having ordinary skill in the art (PHOSITAs) also have common sense, which may be used to glean suggestions from the prior art that go beyond the primary purpose for which that prior art was produced. Id. at 421–22, 127 S. Ct. at 1742. Thus, the Supreme Court taught that a proper understanding of the prior art extends to all that the art reasonably suggests, and is not limited to its articulated teachings regarding how to solve the particular technological problem with which the art was primarily concerned. Id. at 418, 127 S. Ct. at 1741 (‘‘As our precedents make clear, however, the analysis need not seek out precise teachings directed to the specific subject matter of the challenged claim, for a court can take account of the inferences and creative steps that a person of ordinary skill in the art would employ.’’). ‘‘The obviousness analysis cannot be confined . . . by overemphasis on the importance of published articles and the explicit content of issued patents.’’ Id. at 419, 127 S. Ct. at 1741. Federal Circuit case law since KSR follows the mandate of the Supreme Court to understand the prior art— including combinations of the prior art—in a flexible manner that credits the common sense and common knowledge of a PHOSITA. The Federal Circuit has made it clear that a narrow or rigid reading of prior art that does not recognize reasonable inferences that a PHOSITA would have drawn is inappropriate. An argument that the prior art lacks a specific teaching will not be sufficient to overcome an obviousness rejection when the allegedly missing teaching would have been understood by a PHOSITA—by way of common sense, common knowledge generally, or common knowledge in the relevant art. For example, in Randall Mfg. v. Rea, 733 F.3d 1355 (Fed. Cir. 2013), the Federal Circuit vacated a determination of nonobviousness by the Patent Trial and Appeal Board (PTAB or Board) because it had not properly considered a PHOSITA’s perspective on the prior art. Id. at 1364. The Randall court recalled KSR’s criticism of an overly rigid approach to obviousness that has ‘‘little recourse to the knowledge, creativity, and common sense that an ordinarily skilled artisan would have brought to bear when considering combinations or modifications.’’ Id. at 1362, citing KSR, 550 U.S. at 415–22, 127 S. Ct. at 1727. In reaching its decision to vacate, the Federal Circuit stated that by ignoring evidence showing ‘‘the knowledge and perspective of one of ordinary skill in the art, the Board failed to account for critical background information that could easily explain why an ordinarily skilled artisan would have been motivated to combine or modify the cited references to arrive at the claimed inventions.’’ Id.
From Norgren Inc. v. Int’l Trade Comm’n, 699 F.3d 1317, 1322 (Fed. Cir. 2012) (‘‘A flexible teaching, suggestion, or motivation test can be useful to prevent hindsight when determining whether a combination of elements known in the art would have been obvious.’’); Outdry Techs. Corp. v. Geox S.p.A., 859 F.3d 1364, 1370–71 (Fed. Cir. 2017) (‘‘Any motivation to combine references, whether articulated in the references themselves or supported by evidence of the knowledge of a skilled artisan, is sufficient to combine those references to arrive at the claimed process.’’). In keeping with this flexible approach to providing a rationale for obviousness, the Federal Circuit has echoed KSR in identifying numerous possible sources that may, either implicitly or explicitly, provide reasons to combine or modify the prior art to determine that a claimed invention would have been obvious. These include ‘‘market forces; design incentives; the ‘interrelated teachings of multiple patents’; ‘any need or problem known in the field of endeavor at the time of invention and addressed by the patent’; and the background knowledge, creativity, and common sense of the person of ordinary skill.’’ Plantronics, Inc. v. Aliph, Inc., 724 F.3d 1343, 1354 (Fed. Cir. 2013), quoting KSR, 550 U.S. at 418–21, 127 S. Ct. at 1741–42.
The Federal Circuit has also clarified that a proposed reason to combine the teachings of prior art disclosures may be proper, even when the problem addressed by the combination might have been more advantageously addressed in another way. PAR Pharm., Inc. v. TWI Pharms., Inc., 773 F.3d 1186, 1197–98 (Fed. Cir. 2014) (‘‘Our precedent, however, does not require that the motivation be the best option, only that it be a suitable option from which the prior art did not teach away.’’) (emphasis in original). One aspect of the flexible approach to explaining a reason to modify the prior art is demonstrated in the Federal Circuit’s decision in Intel Corp. v. Qualcomm Inc., 21 F.4th 784, 796 (Fed. Cir. 2021), which confirms that a proposed reason is not insufficient simply because it has broad applicability. Patent challenger Intel had argued in an inter partes review before the Board that some of Qualcomm’s claims were unpatentable because a PHOSITA would have been able to modify the prior art, with a reasonable expectation of success, for the purpose of increasing energy efficiency. Id. at 796–97. The Federal Circuit explained that ‘‘[s]uch a rationale is not inherently suspect merely because it’s generic in the sense of having broad applicability or appeal.’’ Id. The Federal Circuit further pointed out its pre-KSR holding ‘‘that because such improvements are ‘technology independent,’ ‘universal,’ and ‘even common-sensical,’ ‘there exists in these situations a motivation to combine prior art references even absent any hint of suggestion in the references themselves.’ ’’ Id., quoting DyStar Textilfarben GmbH v. C.H. Patrick Co., 464 F.3d 1356, 1368 (Fed. Cir. 2006) (emphasis added by the Federal Circuit in Intel). When formulating an obviousness rejection, the PTO may use any clearly articulated line of reasoning that would have allowed a PHOSITA to draw the conclusion that a claimed invention would have been obvious in view of the facts. MPEP 2143, subsection I, and MPEP 2144. Acknowledging that, in view of KSR, there are ‘‘many potential rationales that could make a modification or combination of prior art references obvious to a skilled artisan,’’ the Federal Circuit has also pointed to MPEP 2143, which provides several examples of rationales gleaned from KSR. Unwired Planet, 841 F.3d at 1003.
Claims 33, 40, 50, 51, 66, 69, and 71 are rejected under 35 U.S.C. 103 as being unpatentable over WILLIAMSON (US 4111671) in view of EP 2266771 A2.
WILLIAMSON discloses an apparatus for delivering solid and gaseous carbon dioxide comprising:
(i) a source 12 of liquid carbon dioxide;
(ii) a first conduit 16 having a length and inside diameter, wherein the first conduit comprises a proximal end operably connected to the source 12 of liquid carbon dioxide, and a distal end operably connected to an orifice 32, wherein the first conduit 16 is configured to transport liquid carbon dioxide under pressure to the orifice 32, and wherein the orifice 32 is open to atmospheric pressure, or close to atmospheric pressure, and is configured to convert the liquid carbon dioxide to a mixture of solid and gaseous carbon dioxide as it passes through the orifice;
(iii) a second conduit 40 having a length and inside diameter operably connected to the orifice for directing the mixture of gaseous and solid carbon dioxide to a desired destination; wherein the second conduit has a smooth bore (Figs. 1 and 2);
wherein the first conduit 16 comprises a valve 14 prior to the orifice 32 to regulate the flow of the liquid carbon dioxide; wherein the first and second conduits 16, 40 are not insulated and each have a smooth bore Figures 1-3);
and a third conduit 46 or 52 operably attached to the second conduit 40.
Williamson shows the second conduit 40 being longer in length that the first conduit 16 and a downstream third conduit 46 or 52 in Figure 1 but does not explicitly disclose the following parameters: (a) the recited ratio of the length of the third conduit to the length of the second conduit; (b) the inner diameters of the first conduit, second conduit, and the third conduit; and (c) the lengths of the various conduits.
With respect to these parameters (a) – (c), the examiner has found that the specification contains no disclosure of any unexpected results arising therefrom, and that as such the parameters are arbitrary and therefore obvious. Many different parameter magnitudes are disclosed in the instant specification without any criticality attributed to individual magnitudes of lengths or diameters:
As non-limiting examples from the instant specification:
The first conduit may be of any suitable length, but must be short enough that a significant amount of gas will no accumulate in the conduit (and require removal before liquid carbon dioxide can reach the orifice). Thus, the first conduit can have a length of less than 30, 25, 20, 17, 15, 14, 13, 12, 11, 10, 9, 8, 7, 6, 5, 4, 3, 2, 1, 0.5, or 0.25 feet, and/or not more than 25, 20, 17, 15, 14, 13, 12, 11, 10, 9, 8, 7,6,5,4,3, 2, 1, 0.5, 0.25, 0.1, or 0.01 feet, such as 0.1-25 feet, or 0.1-15 feet, or 0.1-10 feet, or 1-15 feet. Different systems, e.g., systems provided to different customers, may all contain the same length, diameter, and/or material of first conduit, e.g. a conduit of 10-foot length, or any other suitable length [from ¶ 0019].
The second conduit may be, e.g., at least 5, 10, 15, 20, 25, 30, 35, 40, 45, 50, 55, 60, 65, 70, 80, 90, or 100 feet long, in order to reach the final point where carbon dioxide will be used; length of the second conduit will in general depend on the particular operational setup in which carbon dioxide is being used. [from ¶ 0032].
The third conduit may be any suitable inside diameter, so long as it allows for sufficient slowing and clumping for the desired use, for example, at least at least 0.5, 0.6, 0.7, 0.8, 0.9, 1.0, 1.1, 1.2, 1.3, 1.4, 1.5, 1.6, 1.7, 1.8, 1.9, 2, 2.1, 2.2, 2.3, 2.4, 2.5, 2.6, 2.7, 2.8, 2.9, 3, 3.2, 3.4, 3.8, or 4 inches, and/or not more than 0.6, 0.7, 0.8, 0.9, 1.0, 1.1, 1.2,
1.3, 1.4, 1.5, 1.6, 1.7, 1.8, 1.9, 2, 2.1, 2.2, 2.3, 2.4, 2.5, 2.6, 2.7, 2.8, 2.9, 3, 3.2, 3.4, 3.8, 4 or 4.5 inches, such as 0.5-4 inches, or 0.5-3 inches, or 0.5-2.5 inches, or about 2 inches. The third conduit may be any suitable length to allowed desired clumping without slowing the carbon dioxide so much, or for so long, that material sticks to the walls or sublimates to a significant degree, e.g., a length of at least 6, 8, 10, 12, 14, 16, 18, 20, 22, 24, 28, 32, 36, 40, 44, or 48 inches, and/or not more than 8, 10, 12, 14, 16, 18, 20, 22, 24, 28, 32, 36, 40, 44, 48, 54, 60, 72, 84 inches, for example, 2-8 feet, or 2-6 feet, or 3-6 feet, or 3-5 feet. [from ¶ 0034].
Such utterly unsupported limitations cannot be a basis for patentability, since where patentability is said to be based upon particular chosen parameters or upon another variable recited in a claim, the applicant must show that the chosen dimensions are critical. In re Woodruff, 919 F.2d 1575, 1578, 16 USPQ2d 1934, 1936 (Fed. Cir. 1990) and MPEP 2144.05(III).
With respect to the limitations related to said parameters (a) – (c), it would have been obvious to one of ordinary skill in the art to have provided the apparatus defined by the disclosure of Williamson with the configurations and/or dimensions recited in the claims which are considered at most optimum choices, lacking any disclosed criticality.
Applicant has the burden of proving such criticality. In re Swenson et al., 56 USPQ 372; In re Scherl, 70 USPQ 204. However, even though applicant's modification may result in great improvement and utility over the prior art, it may still not be patentable if the modification was within the capabilities of one skilled in the art. In re Sola, 25 USPQ 433; In re Normannet et al., 66 USPQ 308; In re Irmscher, 66 USPQ 314. More particularly, where the general conditions of a claim are disclosed in the prior art, it is not inventive to discover optimum or workable ranges by routine experimentation. In re Aller, 220 F.2d 454, 456, 105 USPQ 233, 235 (CCPA 1955); In re Swain et al., 70 USPQ 412; Minnesota Mining and Mfg. Co. v. Coe, 38 USPQ 213; Allen et al. v. Coe, 57 USPQ 136; MPEP 2144.05(II)(A).
No probative evidence is of record to demonstrate that the dimensions and/or other variables of the invention are significant or are anything more than one of numerous dimensions a person of ordinary skill in the art would find obvious for purposes of merely changing the configurations and/or dimensions to obtain different results. Graham v. John Deere Co., 148 USPQ 459.
Accordingly, the examiner argues that these parameters are rather arbitrary and thus obvious over the prior art per MPEP 2144.05(II)(III).
There is no specific and discrete cause and effect disclosed between the particular parameters recited in the claims and the alleged advantages of the invention.
Furthermore, the Federal Circuit has explained that a reason to optimize prior art parameters may be found in a PHOSITA’s desire to improve on the prior art. In re Ethicon, Inc., 844 F.3d 1344, 1351 (Fed. Cir. 2017) (‘‘The normal desire of artisans to improve upon what is already generally known can provide the motivation to optimize variables such as the percentage of a known polymer for use in a known device.’’).
The subject matter of the pending claims is deemed well within the grasp of 35 USC 103 if not mere common sense since a PHOSITA would have been able to modify said parameters (a) – (c) of the prior art, with a reasonable expectation of success, for the purpose of meeting operational requirements involving maintaining an adequate flow of solid carbon dioxide through the conduits and to enable the downstream conduit(s) to reach the point of use.
As noted herein, the Federal Circuit case law since KSR follows the mandate of the Supreme Court to understand the prior art in a flexible manner that credits the common sense and common knowledge of a PHOSITA. The Federal Circuit has made it clear that a narrow or rigid reading of prior art that does not recognize reasonable inferences that a PHOSITA would have drawn is inappropriate. An argument that the prior art lacks a specific teaching will not be sufficient to overcome an obviousness rejection when the allegedly missing teaching would have been understood by a PHOSITA—by way of common sense, common knowledge generally, or common knowledge in the relevant art. (emphasis added).
Moreover, the instant specification teaches/suggests that said parameters of the conduits are generally adapted for the intended use and environment as would undoubtedly be recognized by one skilled in the art. See, for example ¶ [0032] of the instant specification reproduced in-part:
The second conduit may be, e.g., at least 5, 10, 15, 20, 25, 30, 35, 40, 45, 50, 55, 60, 65, 70, 80, 90, or 100 feet long, in order to reach the final point where carbon dioxide will be used; length of the second conduit will in general depend on the particular operational setup in which carbon dioxide is being used. Because the first conduit typically is kept as short as possible, and the second conduit must be a length suitable to reach to point of use, which is often far from the injector orifice, the ratio of length of the second conduit to that of the first conduit can be at least 0.5, 0.7, 1.0, 1.2, 1.5, 2.0, 2.5, 3.0, 3.5, 4.0, 4.5, 5.0, 6, 7, 8, 9, or 10, or greater than 10. For example, the first conduit can be not more than 10 feet long while the second conduit may be at least 20, 30, 40, or 50 feet long.
Thus, for one skilled in art to alter the lengths, inner diameters, and comparative ratios of any of the conduits used within a fluid supply system (as in WILLIAMSON) to suitably adapt such conduits to the types of fluids being conveyed, the surrounding environment, intended use, distance between the fluid supply and the point of use, and the like is deemed well within the realm of obviousness, if not sheer common sense.
Williamson does not disclose the second conduit being insulated. EP 2266771 A2 discloses a device used in the production of fresh concrete wherein it is not uncommon for aggregates, for example cement or sand, to be cooled before admixture in order to prevent excessively high temperatures during setting. In this case, the aggregate is usually brought into direct contact with liquid nitrogen or liquid carbon dioxide as the cooling medium and thereby cooled. The object of the invention is therefore to provide a way to enter and cool streams, in particular for entering and cooling of cement, which allows efficient cooling and at the same time reduces the burden on people and the environment.
This object is achieved in a device of the aforementioned type and purpose in that the nozzle is equipped with a mixing chamber into which the delivery line opens with a mouth portion, and at which the at least one cooling medium supply with a mouth portion so at an acute angle to the longitudinal axis the supply line is arranged inclined that a Cooling medium flow is discharged from the cooling medium supply with a directional component in the direction of the nozzle opening.
The delivery line and the cooling medium supply are thus fluidly connected to each other only at the nozzle, which opens into the interior of the storage container (silo). Both streams thus only come into direct contact with the nozzle at the nozzle. The mixture begins inside the nozzle and continues after discharge of the streams from the nozzle outside the nozzle. The mixing of the two streams, and thus the phase transition of the cooling medium, so at least for a substantial part only outside of the nozzle and thus the delivery line instead. On the one hand a good cooling effect is achieved, on the other hand, the known from the prior art, caused by a phase transition of the cooling medium in the interior of the delivery line impulsive disturbances in the mass transfer and thus the intermittent blowing off of dusts are avoided. Nevertheless, the substances come into contact with each other so intensively that a good heat transfer is ensured and the enthalpy of the cooling medium is used well. As a result of the acute-angled flow guidance of the cooling medium, that is to say with a component in the direction of the nozzle orifice, a cooling medium flow spirally enveloping the flow of material leaves the nozzle at the nozzle orifice together with the flow of material. This avoids direct contact of the material flow with the walls of the nozzle, which would otherwise be abrasive and reduce the life of the nozzle. The angle at which the supply lines for the cooling medium are inclined with respect to the longitudinal axis of the delivery line is determined according to the respective requirements. The steeper the cooling medium is introduced into the stream, the faster the substances are mixed with each other, the lower, however, is the formation of the stream enveloping the flow of cooling medium. The preferred cryogenic cooling medium is liquid or cold gaseous nitrogen or liquid or cold gaseous carbon dioxide.
An advantageous development of the invention provides that the mouth portion of the delivery line at its entry into the mixing chamber, a nozzle-like constriction, a so-called confuser. The confuser reduces the flow cross-section of the material flow and thereby increases the speed of the jet emerging from the two-substance nozzle, stabilizes it with it and thus extends the mixing distance of solid and cooling medium. In addition, the high velocity of the material flow leads to a negative pressure in the mixing chamber, the suction effect of which promotes the introduction of the cooling medium into the mixing chamber.
The object of the invention is also achieved by a method for cooling a pulverulent substance, in which the material flow is fed via a feed line connecting a storage tank to a storage container and brought into contact with a cryogenic cooling medium at a nozzle opening into the storage container with a nozzle opening, and that according to the invention is characterized in that the material flow is discharged as a particle flow and the cooling medium at least partially as a cooling medium flow enveloping the particle flow through the nozzle opening. The cooling medium flow surrounding the particle jet in particular prevents abrasive damage to the nozzle due to the exiting particle flow and thus prolongs the service life of the nozzle. At the same time it causes an intimate mixing of cooling medium and material flow after exiting the nozzle orifice.
Preference comes as a material to be cooled flow of a building material, such as cement, and liquid medium as cold or cold gaseous nitrogen or liquid or cold gaseous carbon dioxide used.
According to the device according to the invention Fig. 1 a powdered substance, in the embodiment cement, from a delivery vehicle 1 pneumatically fed into a silo 10. At the silo head a dedusting filter 11 is arranged. The feed takes place from the delivery vehicle 1 via a supply line 2, which is connected via a connection with a delivery line 9. The delivery line 9 opens at a nozzle 8 in the silo 10 a. A cooling medium, liquid or cold gaseous nitrogen in the exemplary embodiment, is conducted via a coolant line 3 through a flow meter 4 to a control valve 6, which is regulated by means of a control unit 5 to a specific flow rate fixed or fixed in dependence on measured parameters. Subsequently, the cooling medium is transported via a cooling medium line 7 to the nozzle 8. In the cooling medium lines 3, 7 is in the case of cooling with a cryogenic cryogenic medium, such as liquid nitrogen, heat-insulated lines, in the case of a pressure-liquefied cryogenic medium, such as liquid carbon dioxide to pressure-resistant lines. In a manner not shown here, the control unit 5 is in data communication with a sensor for detecting the temperature of the cement stored in the silo 10 and / or a sensor for detecting the solids content in the exhaust air supplied to the dedusting filter 11 and thus enables a function of predefined values Cement temperature or the solids content controlled supply of the cooling medium.
Instead of a liquefied cryogenic cooling medium and cold gaseous cooling media can be used, such as a gas, for example nitrogen, argon or carbon dioxide, which is maintained at a temperature which is equal to or slightly more than the boiling point at the corresponding pressure conditions in the cooling medium supply 7 becomes. Likewise, carbon dioxide or another pressure-liquefied gas can be used, which is transported in the liquid state under pressure to the two-fluid nozzle 8 and is expanded in the two-fluid nozzle 8 or before its mouth with cold development. The device according to the invention is not limited to the cooling of cement but can generally be used for cooling powdered or free-flowing substances with a cryogenic cooling medium.
It would have been obvious to one skilled in the art before the effective filing date of the invention to have insulated any of the conduits, including the second conduit in WILLIAMSON as taught by EP 2266771 A2 for the purpose of minimizing heat gain to the substances flowing through the conduit(s).
Claim 68 is rejected under 35 U.S.C. 103 as being unpatentable over WILLIAMSON (US 4111671) in view of EP 2266771 A2 as applied to claim 33 and further in view of CONSTANTZ et al. (US 2010/0132556 A1).
WILLIAMSON does not disclose the second conduit having an inner material comprising PTFE.
CONSTANTZ et al. discloses an apparatus for processing carbon dioxide that employs ducting [conduits] that is formed of stainless steel or inner lined with a fluorocarbon (such as polytetrafluoroethylene - PTFE).
It would have been obvious and mere common sense to one skilled in the art before the effective filing date of the invention to have provided the conduits in WILLIAMSON with an inner liner material that includes PTFE (a low friction material) as disclosed by CONSTANTZ et al. for the purposes of reducing the adverse impact of condensation on said conduits, to prevent the ducting/conduits from deterioration, and to enable smooth flow of the fluids through the conduits via the low-friction liner material ¶ [0065].
Claims 41, 44, 45, and 46 are rejected under 35 U.S.C. 103 as being unpatentable over WILLIAMSON (US 4111671) in view of EP 2266771 A2 as applied to claim 40 and further in view of FORGERON et al. (US 2016/0280610 A1).
Modified WILLIAMSON does not disclose the recited sensors and the controller of claims 41, 44, 45, and 46. Forgeron et al. ‘610 discloses an apparatus for delivering carbon dioxide in solid and gaseous form to a destination (para [0004], [0050]), comprising transporting liquid carbon dioxide from a source of liquid carbon dioxide to an orifice via a first conduit (para [0023]), wherein solid and gaseous carbon dioxide is produced as the carbon dioxide exits the orifice (para [0025), (0047]); transporting the solid and gaseous carbon dioxide through a second conduit (para [0069], [0070], wands being 5-30 feet long); and directing the carbon dioxide that exits the second conduit to a destination (para [0074]). The conduits are not insulated (para [0024]) since the description and Figures are absent related to a discussion or showing of insulation. Forgeron further discloses varying the length of the second conduit (para [0069], [0070], wands being 5-30 feet long) and wherein the first conduit has a length of less than 15 feet (para [0069], [0070]). Forgeron discloses wherein the second conduit comprises an inner material of plastic (para [0074]). Forgeron further discloses wherein the first conduit comprises a valve for regulating the flow of carbon dioxide (para [0034]), a pressure sensor 120, a temperature sensor 118, and a control system 128 connected to these sensors 118, 120; whereby a pressure and a temperature between the valve and the orifice is determined (para [0034], [0035]), and determining a flow rate for the carbon dioxide based on the temperature and the pressure (para [0035]); wherein the controller 128 receives a pressure from the first pressure sensor 120 and a temperature from the temperature sensor 118 and calculates a flow rate of carbon dioxide in the system from the pressure and temperature, wherein the controller calculates the flow rate at least in part based on a set of calibration curves for the apparatus. (¶ [0034], [0035]).
More specifically, Forgeron et al. 610 discloses methods and compositions to contact cement mixes with carbon dioxide and for cement mixes containing incorporated carbon dioxide and carbonation products. In certain situations in which a mixture of solid and gaseous carbon dioxide is delivered by forcing pressurized liquid carbon dioxide, or a mixture of gaseous and liquid carbon dioxide, through an orifice to a lower pressure environment, it is desirable to determine the flow rate of the carbon dioxide and/or total amount of carbon dioxide delivered without the use of, e.g., changes in weight of carbon dioxide source container or containers, which can be inaccurate at small doses, or, e.g., a mass flow controller or other direct measurement of flow. In addition, it is often desirable to deliver such a mixture of solid and gaseous carbon dioxide to a mix, such as a cement mix, using apparatus and methods to optimize the uptake of the carbon dioxide into the mix, especially at low doses of carbon dioxide.
In one aspect, the invention provides apparatus. In certain embodiments, the invention provides an apparatus for determining a flow rate of carbon dioxide, comprising i) a delivery line through which flows gaseous carbon dioxide, liquid carbon dioxide, or a combination of gaseous and liquid carbon dioxide; ii) an orifice at the distal end of the delivery line, through which the carbon dioxide exits from the delivery line, having a diameter of the delivery line as it joins the orifice; a first temperature sensor proximal to the orifice and configured to detect a first temperature, T, of carbon dioxide in the delivery line and to transmit the detected first temperature to a flow rate calculation system; iv) a pressure sensor proximal to the orifice and configured to detect a pressure of carbon dioxide in the delivery line and to transmit the detected pressure to the flow rate calculation system; v) a second temperature sensor distal to the orifice and configured to detect a second temperature of carbon dioxide exiting the orifice and to transmit the detected second temperature to the flow rate calculation system. The apparatus of can further comprise vi) the flow rate calculation system, wherein the flow rate calculation system is configured to a) at a first time, determine whether the carbon dioxide in the delivery line when it reaches the orifice is 100% gas or 100% liquid, or a mix of gas and liquid, and b) calculate an instantaneous flow rate for the first time, wherein 1) when the carbon dioxide in the delivery line as it is delivered to the orifice is 100% gas or 100% liquid, the flow rate is calculated for the first time and 2) when the carbon dioxide in the delivery line as it is delivered to the orifice is a mixture of gas and liquid, the flow rate is calculated at the first time. The apparatus can further comprise a mixer for mixing concrete or a container containing a material used in concrete, wherein the apparatus is configured to deliver carbon dioxide to the mixer or the container. In certain embodiments, the apparatus comprises a mixer for mixing concrete, such as a transportable mixer, for example the drum of a ready-mix truck. In certain embodiments the mixer comprises a stationary mixer. The apparatus can further comprise a conduit operably connected to the distal end of the orifice and configured to direct the carbon dioxide to a destination. In certain embodiments, the conduit is attached to the ready-mix truck. In certain embodiments, not attached to a ready-mix truck. In certain embodiments, the flow rate calculation system is configured to calculate the flow rate of carbon dioxide at a plurality of times or time intervals. The flow calculation system is configured to calculate a total amount of carbon dioxide that has flowed through the orifice based on the instantaneous flow rates for the plurality of times or time intervals. In certain embodiments, the flow rate calculation system outputs the total amount of carbon dioxide to a system controller. In certain embodiments, the system controller compares the total amount of carbon dioxide to a predetermined end amount of carbon dioxide, and when the total amount is equal to or greater than the predetermined end amount, sends a signal to one or more actuators configured to modulate the flow of carbon dioxide through the orifice to cause the one or more actuators to modulate the flow of carbon dioxide, for example to slow or cease flow of the flow of carbon dioxide. In certain embodiments, the source of gaseous carbon dioxide and the source of liquid carbon dioxide are the same. In certain embodiments, the source of gaseous carbon dioxide and the source of liquid carbon dioxide are different.
In certain embodiments the invention provides a system for delivering carbon dioxide to a drum of a ready-mix truck comprising (i) a rigid or semi-rigid conduit comprising a proximal end and a distal end, wherein the conduit is configured to be operably connected to a source of carbon dioxide at its proximal end for delivery of the carbon dioxide from its distal end to a drum of a ready-mix truck; and (ii) a guide affixed to the ready-mix truck, wherein the guide is configured to reversibly attach the conduit to the ready-mix truck and to position the distal end of the conduit at a desired position in the drum of the ready-mix truck in order to deliver carbon dioxide from the carbon dioxide source to concrete mixing within the drum. The guide can be configured to position the distal end of the conduit to within 10-40 cm of the surface of the mixing concrete, on average, when the drum of the ready-mix truck contains a full load of concrete. The system can further comprise the source of carbon dioxide. The source of carbon dioxide can be a source of liquid carbon dioxide, and the system can further comprise an orifice operably connected to the proximal end of the rigid or semi-rigid conduit, wherein the orifice is operably connected to the source of carbon dioxide and is configured to convert the liquid carbon dioxide from the source of carbon dioxide to solid and gaseous carbon dioxide for delivery through the conduit to the concrete. The orifice can be operably connected to the proximal end of the rigid or semi-rigid conduit by a flexible conduit, where the orifice is positioned at a proximal end of the flexible conduit and the proximal end of the rigid or semi-rigid conduit is attached to a distal end of the flexible conduit. The orifice can comprise a temperature sensor for sensing the temperature of the mixture of solid and gaseous carbon dioxide exiting the orifice.
In certain embodiments, the invention provides a method for determining a flow rate of carbon dioxide in a system where a mixture of liquid and gaseous carbon dioxide is delivered via a conduit to an orifice, wherein the orifice has a cross-sectional area, and exits the orifice as a mixture of gaseous and solid carbon dioxide, comprising (i) determining a first temperature of the carbon dioxide exiting the orifice; (ii) determining a pressure of the carbon dioxide in the conduit proximal to the orifice; (iii) determining a second temperature of the carbon dioxide in the conduit proximal to the orifice; (iv) at a first time, determining the proportions of liquid carbon dioxide in the total carbon dioxide delivered to the orifice at the first time; (v) determining the flow rate for the carbon dioxide delivered to the orifice at the first time at the first time, and the diameter, of the orifice, the proportion of liquid carbon dioxide delivered to the orifice. In certain embodiments, the determining is performed in less than 100 ms. In certain embodiments, the determining is performed in less than 20 ms. In certain embodiments, the determining is performed in less than 5 ms. The method may further comprise performing steps (i) through (v) at least 100 times subsequent to the first time. The method may further comprise performing steps (i) through (v) at least 1000 times subsequent to the first time. In certain embodiments, a plurality of flow rates are determined at a plurality of times, and the total amount of carbon dioxide delivered is determined from the plurality of flow rates and the times.
In certain embodiments, the invention provides a method of carbonating a flowable concrete mix comprising i) delivering carbon dioxide to the concrete mix; wherein the carbon dioxide is delivered as a mixture of gaseous and solid carbon dioxide for at least part of the delivery time wherein the carbon dioxide is delivered by a method comprising a) the carbon dioxide is delivered via a delivery line with diameter to an orifice with diameter and through the orifice, optionally also through a conduit attached to the orifice, to the concrete mix, b) carbon dioxide is supplied to the delivery line by flowing pressurized gaseous carbon dioxide to the delivery line via a carbon dioxide gas line and/or flowing pressurized liquid carbon dioxide to the delivery line via a carbon dioxide liquid line, so that at least part of the carbon dioxide reaching the orifice during delivery of the carbon dioxide to the concrete mix is liquid carbon dioxide, c) the carbon dioxide exits the orifice as a gas, a solid, or a mixture thereof, ii) determining a total amount of carbon dioxide delivered to the concrete mix by a method comprising a) determining a pressure of the carbon dioxide in the delivery line proximal to the orifice at a plurality of times, b) determining a first temperature of the carbon dioxide, T, in the delivery line proximal to the orifice at the plurality of times, c) determining a second temperature of the carbon dioxide as it exits the orifice at the plurality of times; d) determining from for each time whether the carbon dioxide in the delivery line when it reaches the orifice is 100% gas or 100% liquid, or a mix of gas and liquid, e) calculating an instantaneous flow rate for each time, wherein 1) when the carbon dioxide in the delivery line as it is delivered to the orifice for a time is 100% gas or 100% liquid, the flow rate is calculated for that time, and 2) when the carbon dioxide in the delivery line as it is delivered to the orifice for a time is a mixture of gas and liquid, the flow rate is calculated f) integrating [calibration curves] the flow rates for the plurality of times to obtain a total amount of carbon dioxide delivered; and iii) modulating the delivery of the carbon dioxide to the concrete mix based at least in part on the total amount of carbon dioxide delivered determined in ii) f). In certain embodiments, the modulation of delivery of the carbon dioxide comprising halting the delivery of carbon dioxide when the total amount of carbon dioxide delivered is greater than or equal to a predetermined amount of carbon dioxide.
The invention provides compositions and methods for delivering carbon dioxide, e.g., to a concrete mixing operation; in certain embodiments the invention provides compositions and methods for determining a flow rate of the carbon dioxide by measurement of temperature and pressure. In particular, the invention provides compositions and methods for delivering pressurized liquid and gaseous carbon dioxide to and through an orifice from high pressure to low pressure, e.g., atmospheric pressure, causing the liquid carbon dioxide to become a mixture of solid and gaseous carbon dioxide. Solid carbon dioxide is also referred to as “dry ice” herein. When a mixture of solid carbon dioxide and gaseous carbon dioxide is formed as a result of a sudden release of pressure of a liquid carbon dioxide, the solid carbon dioxide in the mixture is also referred to herein as “snow.” The invention further provides compositions and methods for measuring the rate of delivery of carbon dioxide through the orifice that combine temperature and pressure measurements at various points to determine a total amount of carbon dioxide delivered. Control systems can be used to cause the flow to stop after a desired amount of carbon dioxide has been delivered through the orifice.
The compositions and methods of the invention find use anywhere that it is desired to deliver carbon dioxide, especially in the form of a mix of gaseous and solid carbon dioxide, and most especially in smaller amounts; in certain embodiments the methods and compositions of the invention include methods and compositions for delivery of carbon dioxide to a concrete mix, such as in a concrete mixer (e.g., a drum of a ready-mix truck, or a stationary mixer such as at a precast plant) or elsewhere, or to a component of a concrete mix, and for convenience the invention will be described in terms of these embodiments, however, it is understood that aspects of the invention, such as determining flow rates of carbon dioxide, are not confined to delivery of carbon dioxide to concrete mixes or components of concrete mixes and may be used in any operation in which carbon dioxide delivery, especially delivery of gas/solid carbon dioxide mixture, and/or measurement of flow rate and/or total amount delivered is desired. It is especially useful in systems in which a relatively small dose of carbon dioxide is desired, e.g., a system in which other means of determining total amount of carbon dioxide delivered, for example, by measuring the change in weight or mass of the carbon dioxide container, are not accurate enough to provide useful information; it will also be appreciated that measuring the change in weight of the source container is not an accurate measure of carbon dioxide actually delivered if any carbon dioxide in the delivery line is vented during delivery. It is also useful when the use of a mass controller, with concomitant necessity for pure liquid or pure gas in the delivery line at the point of flow measurement, is not feasible or desirable.
In general, carbon dioxide delivery in which flow is determined by certain compositions and methods of the invention involves the following steps: first, a delivery line with an orifice at its distal end is pressurized by introduction of gaseous carbon dioxide into the delivery line, to pressurize the line sufficiently that when liquid is introduced into the line, the pressure drop will not be such that solid carbon dioxide is formed, e.g., pressurized to a certain minimum pressure that is such that the pressure difference between it and the pressure of the liquid carbon dioxide is not sufficient to cause solid carbon dioxide formation; often a certain safety cushion is added to the minimum pressure to ensure that no solid carbon dioxide forms. Next, liquid carbon dioxide is introduced into the delivery line; the gas flow continues briefly to ensure that there is no drop in pressure, and is then halted so that only liquid is supplied to the delivery line. When it is desired to halt the liquid flow, gaseous carbon dioxide is again briefly introduced into the delivery line and the delivery of liquid carbon dioxide to the line is halted. The burst of gas into the line serves to push all liquid out of the orifice. Thus, in sequence during the simplest case of delivery of carbon dioxide to the orifice, only gas is delivered, a mixture of gas and liquid is delivered, only liquid is delivered, a mixture of gas and liquid, and finally only gas. On exiting the orifice, the liquid carbon dioxide experiences a pressure change from high pressure in the delivery line (e.g., 300 psi) to atmospheric pressure. The liquid is not stable at atmospheric pressure and it undergoes a transition to gas and solid carbon dioxide.
An exemplary orifice is illustrated in FIG. 1. The dimensions are for use in delivering carbon dioxide to a concrete mix for carbonation of the mix and are those useful in that operation, where a total dose of 1-5 L of liquid carbon dioxide may be delivered over a period of less than 5 minutes. It will be appreciated that smaller dimensions may be used for lower doses and larger dimensions for higher doses, and any suitable dimensions may be used. Of note is that the orifice comprises a connection for a temperature sensor, which measures the temperature of the carbon dioxide exiting the orifice; the carbon dioxide exiting the orifice is referred to herein as distal to the orifice or downstream of the orifice. The ½″ NPT connection is for connection of a conduit to direct the carbon dioxide exiting the orifice to the desired location. For example, the conduit may be used to direct carbon dioxide to a particular location in a concrete mixer, such as a particular location in a drum of a ready-mix truck. Certain embodiments of the invention provide one or more of an orifice as described, a conduit operably connected to the orifice to direct the carbon dioxide exiting the orifice, and, in some embodiments, a system for positioning the conduit so as to direct the carbon dioxide to a particular location, for example, a particular location in a drum of a ready-mix truck; the conduit apparatus may be affixed to the drum in a permanent or, preferably, temporary configuration. Certain embodiments of the invention provide for the positioning system itself, alone or affixed to a mixer, e.g., a ready-mix truck, or a plurality of positioning systems, each affixed to a separate mixer, e.g., to separate ready-mix trucks. Thus, for example, in a ready-mix operation, each truck that is designated as a potential receiver of carbon dioxide may have its own positioning system, e.g., a holster, affixed thereto in such a location as to position the conduit to deliver carbon dioxide to a desired location inside the drum of the truck while concrete is mixing in the drum, so that the conduit may be temporarily attached to different ready-mix trucks as desired to deliver carbon dioxide to the different trucks. Hence, in certain embodiments, the invention provides systems and methods for delivery of carbon dioxide to the drums of one or more ready-mix trucks where each truck to which carbon dioxide is to be delivered has affixed thereto a positioning system that travels with the truck, and a carbon dioxide delivery systems, for example as described herein, that includes a conduit for delivery of carbon dioxide from a source of carbon dioxide to the ready-mix truck, where each positioning system is affixed in a location and position such that the conduit may be temporarily attached to the truck and positioned in such a way as to allow carbon dioxide to be delivered to a desired location within the drum of the truck, for example, while concrete is mixing in the drum of the truck. Locations and positioning may be as described herein. The system may include at least 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 12, 15, 20, 25, 30, 40, or 50 separate ready-mix trucks, each with its own positioning system attached, and 1 or, in some cases, more than 1, such as 2, 3, 4, 5, or more than 5 carbon dioxide delivery systems that include a conduit that may be temporarily attached to the trucks for delivery of carbon dioxide from a source of carbon dioxide to the drum of the truck. The carbon dioxide delivery system may be positioned, when in use, at a location where the truck or trucks normally halt for a period sufficient to deliver a desired dose of carbon dioxide to the concrete in the truck, for example, at a location where the trucks normally halt for at least 1, 2, 3, 4, 5, 6, 7, 8, 9, or 10 minutes. For example, the delivery system may be positioned at a wash rack in a batching facility. In this way, carbon dioxide can be delivered to the trucks without significantly altering the time the trucks remain in the batching facility, as it is delivered during an operation that would normally take place, e.g., washing the trucks, and the only potential additional time would be in the attachment and detachment of the conduit, and in some cases the starting and stopping of delivery of the carbon dioxide, if done by the truck driver. Thus, the system and methods may allow delivery of a desired dose of carbon dioxide to the ready-mix trucks, such as a dose of 0.05-2% bwc, or any other dose as described herein, without prolonging the average time that a truck remains in the batching facility by more than 1, 2, 3, 4, 5, 6, 7, 8, 9, or 10 minutes, for example, by no more than 2 minutes, or no more than 4 minutes, or no more than 6 minutes, on average. The carbon dioxide delivery system may be a liquid delivery system and further include an orifice that allows liquid carbon dioxide, or a mixture of liquid and gaseous carbon dioxide, under pressure, to be converted to solid and gaseous carbon dioxide as it passes through the orifice to an area of lower pressure, for example, to an area of atmospheric pressure, as described herein. Systems and methods for monitoring the flow of carbon dioxide, such as those described herein, may be included in the systems and methods of delivering carbon dioxide to the drums of ready-mix trucks. Systems and methods for controlling the flow of carbon dioxide, such as those described herein, such as starting, stopping, and/or otherwise modulating the flow, may be included in the systems and methods of delivering carbon dioxide to the drums of ready-mix trucks.
The compositions and methods of the invention include determination of a flow rate of carbon dioxide by measuring a temperature and a pressure in the delivery line proximal to the orifice; a temperature of the delivered carbon dioxide distal to the orifice is also measured to determine what proportion of liquid and gaseous carbon dioxide is being delivered to the orifice; if the delivery line diameter and the orifice diameter are known, the flow rate for liquid carbon dioxide and for gaseous carbon dioxide may be calculated; integration of the flow rate gives total amount of carbon dioxide delivered through the orifice in a given time. The temperature distal to the orifice is used to determine which phase (liquid or gas or both) is in the line and the equation settings are changed based on the phase to calculate the instantaneous flow rate. Integrating the flow over time allows the total amount of carbon dioxide delivered in that time to be calculated. In some cases a pressure distal to the orifice may also be used, if the pressure cannot be assumed to be atmospheric.
The temperature distal to (downstream of) the orifice is used in the following manner: When only the liquid valve is open in the system, 85-100% liquid is flowing through the orifice and allowed to expand to atmospheric pressure, a temperature at or below −56° C. is seen in the stream exiting the orifice. When 100% gas, e.g., from the head space above the liquid in a liquid pressurized portable liquid carbon dioxide tank (such as a Dewar) or other pressurized gaseous CO2 source, is allowed to expand to atmospheric pressure. Above this temperature, the flow distal to the orifice is 100% gas, below this it is a mixture of gas and solid (meaning some liquid is flowing through the orifice) until a temp of −56° C. is reached, at which the flow to the orifice is 100% liquid. If the temperature distal to the orifice is between these values one may interpolate between the two temperatures to determine the % liquid vs gas being delivered to the orifice. This is a linear relationship, or can be estimated or represented as a line.
FIG. 2 illustrates various exemplary times in a carbon dioxide delivery process and the content of the delivery line (gas, liquid, mixture of gas and liquid) as well as the composition of the carbon dioxide exiting the orifice (gas, mixture of gas and solid), and the temperatures associated therewith. In FIG. 2a, the gas line valve is opened and gas purges the delivery line and brings it up to pressure. The gas is no colder than the temperature at which carbon dioxide would liquefy at the pressure in the line, e.g., no colder than −20° C. at 300 psi, and the carbon dioxide exiting the orifice is in gaseous form. Because the orifice diameter is much less than the diameter of the delivery line, the delivery line can be pressurized due to the back pressure at the orifice without closing off the orifice. In FIG. 2b the liquid valve is opened and the gas valve remains open in order to assure that the pressure remains high; there is a co-flow of gas and liquid in the delivery line. The temperature distal to the orifice decreases as liquid carbon dioxide is converted to solid and gas, and the carbon dioxide exiting the orifice is a mixture of gas and solid. In general this period is brief, as the gas valve quickly closes once the liquid valve opens, since it is no longer needed to keep the line pressurized. The temperature distal to the valve is between that of the gas and the liquid (−20 to −56° C.), depending on the proportions of gas and liquid reaching the orifice. In FIG. 2c, the gas valve has closed and only the liquid valve is open, and during this interval the remaining gas in the line is pushed out by liquid flow, so there is still a mixture of gas and liquid in the delivery line, (FIG. 2c shows only the liquid in the line, but it is preceded by a liquid/gas mixture). The temperature distal to the orifice reflects that flow is still not 100% liquid while the gas/liquid mixture is pushed out, and the proportion of gas and liquid in the carbon dioxide reaching the orifice can be determined based on the temperature distal to the orifice. This period is also brief, as it continues only until all gas is pushed out of the line, and a mixture of gas and solid dioxide exits the orifice. In FIG. 2d, only the liquid valve is open, all gas has been pushed out of the line, and there is full liquid flow in the delivery line to the orifice. The liquid carbon dioxide converts to approximately 50% gas and 50% solid carbon dioxide after orifice; this can range from about 40% to 60% solid depending on temperature and pressure. This period can be any desired period, e.g. if a large amount of carbon dioxide is to be delivered the period of 100% liquid flow in the delivery line can be long; for a small dose of carbon dioxide, the period can be brief. The temperature distal to the orifice will be between that of the liquid (−56° C.) and the solid carbon dioxide (−78° C.), depending on the proportions of gas and solid in the carbon dioxide exiting the orifice.
Not shown in FIG. 2 is the shutdown procedure, in which the gas valve opens, then the liquid valve closes, so that, again, both gas and liquid are in the delivery line and finally just gas, as the last of the liquid is forced out of the orifice, with the mixture of gas and solid and temperature of the mixture exiting the orifice reflecting the proportion of gas and liquid in the line. The final portion of carbon dioxide in the delivery line and exiting the orifice will be 100% gas, just as at the beginning of the delivery process.
It will be appreciated that when only the liquid valve is open and all gas from the period when the gas valve was opened is flushed from the system, the carbon dioxide in the delivery line that reaches the orifice can nonetheless be a mixture of liquid and gaseous carbon dioxide due to formation of gaseous carbon dioxide from liquid in the line, for a variety of reasons; for example, temperature losses in the supply line, from the liquid source to the delivery system, or pressure drops through piping and fittings due to changes in diameter. Thus, it cannot be assumed that flow is 100% liquid even after the gas valve has been closed for a significant time, and the downstream (distal) temperature must be relied on to establish the fraction of carbon dioxide in the delivery line as it reaches the orifice that is liquid vs. gas.
In addition, although the process has been described as one cycle, during any given period of carbon dioxide delivery it may be desired to modulate the delivery rate of the carbon dioxide. Since liquid carbon dioxide is approximately 500 times more dense than gaseous carbon dioxide, the gas valve may be opened to introduce gas into the carbon dioxide in the delivery line, with or without closure of the liquid valve, thus decreasing the proportion of liquid and decreasing delivery rate for the carbon dioxide.
The proportion of gas and liquid flow in the delivery line can be determined based on the temperature of the carbon dioxide exiting the orifice; for one-phase flow in the line, e.g., either 100% liquid flow or 100% gas flow. As described, when flow in the delivery line is nominally 100% liquid flow (i.e., liquid valve open, gas valve shut, all gas flushed from line), the actual flow can vary between about 85-100% liquid flow, that is, due to various conditions, up to 15% of the liquid in the line can convert to gas, assuming liquid up to the orifice and not heating in the line; if the supply line heats up due to, e.g., ambient temperature, etc., than this can be >15%. In addition, the percentage of carbon dioxide exiting the orifice that is solid can vary from 40-60% of the total carbon dioxide. Under conditions where the carbon dioxide in the delivery line as delivered to the orifice contains both the gas and the liquid phase. The flow rate can be determined for a succession of times; the interval between one flow determination and another is limited only by the speed at which values may be determined and the speed at which the calculations to determine flow performed. In certain embodiments, the interval between flow rate determinations is 0.01-100 ms, for example, 0.1-10 ms, such as 0.5-5 ms. At a time interval of 1 millisecond (ms) between flow rate determinations, 1000 determinations per second may be made. For a succession of flow rates, flow rate may be integrated over time to give total carbon dioxide delivered in that time.
The calculations to determine flow rate and/or total amount of carbon dioxide delivered in a given time may be performed by any suitable apparatus capable of the requisite speed of calculation, such as a computer, e.g., a programmable logic controller (PLC). It will be appreciated that the calculation apparatus will perform calculations based on the inputs it receives at any particular time, but, due to the fact that each is measured by a different sensor and transmitted to the calculation apparatus separately, the actual time of each measurement for P and T may be slightly different; for the purposes of this description, measurements of P and T and any other measurements that may be used in the calculation of a flow rate, are considered to be at “the same time” if they are all used by the calculation apparatus to calculate a flow rate for that time, even though they may not have been measured at precisely the same time or at precisely the time at which the calculation apparatus performs the calculation.
Any suitable apparatus, as known in the art or that may be developed, may be used to deliver the gaseous and liquid carbon dioxide to the delivery line and to determine the temperatures and pressure proximal (upstream) to the orifice and temperature distal (downstream) of the orifice (and, optionally, pressure downstream of the orifice if it cannot be assumed to be atmospheric pressure), and, as described above, to perform the necessary calculations to determine a flow rate and/or total amount of carbon dioxide delivered. The source of the gaseous carbon dioxide may be any suitable source, such as a container that contains both liquid and gaseous carbon dioxide and from which gaseous carbon dioxide can be withdrawn. For smaller operations, the container can be, e.g., a pressurized portable liquid carbon dioxide tank. The source of the liquid carbon dioxide may be any suitable source, such as a container that contains liquid carbon dioxide and from which liquid carbon dioxide can be withdrawn. For smaller operations, the container can be, e.g., a pressurized portable liquid carbon dioxide tank. The sources may be the same, e.g., a container that contains both liquid and gaseous carbon dioxide where the gaseous carbon dioxide is withdrawn at one port and the liquid carbon dioxide at another.
Certain embodiments of compositions of the invention may be understood in reference to FIG. 3: A gas line [102] and liquid line [104] are input into the valve assembly. Each line has a ball valve [106], pressure gauge [108] and pressure relief valve [110] leading into a solenoid valve, sometimes referred to herein as a solenoid. When CO2 is to be delivered through the orifice, the gas solenoid [112] opens briefly, e.g., for 0.1-10 seconds, to pressurize the piping prior to opening the liquid valve. Once the outlet line is pressurized the liquid solenoid [114] opens and the gas solenoid [112] closes soon thereafter, e.g., 0.1-5 seconds later; in certain cases, the liquid solenoid and gas solenoid may open at the same time, depending on the pressure in the line. When the liquid valve is to close, the gas solenoid [112] opens briefly, e.g., for 0.1-5 seconds (or longer, depending on the distance between the solenoid and the orifice; the time is sufficient to empty the line, which will depend on the configuration), and the liquid solenoid [114] closes. The gas solenoid [112] remains open for another brief period, e.g., for 0.1-10 seconds. Prior to liquid injection gas is used to pressurize the pipe between the solenoid and the orifice [122] to ensure that pressure is sufficient to ensure that the incoming liquid remains liquid. After the liquid injection phase, the gas is used to push all the liquid out of the orifice and clear the liquid from the pipe between of the solenoid and the orifice. Feedback that confirms 100% gas flow based on temperature determined by the downstream thermocouple may be used.
Both the gas and liquid are forced through an orifice [122] in order to obtain the desired flow rate. During some, or preferably the entire, injection progress (gas-liquid-gas), pressure and temperature are measured and an equation is used to calculate the flow through the orifice, for example, to determine the amount of CO.sub.2 injected, as described above. A temperature sensor [118] and a pressure sensor [120] act in-line ahead of (proximal to) the orifice and feed information into a calculating system, for example, a programmable logic controller, PLC [128]. Some or all of the mechanical valves can be controlled by a PLC and some or all of the sensors can be read by a PLC. The 2 solenoids [112 and 114] open and close (using the sequence described above) to control the flow rate and the average is measured and is used to calculate the amount of CO.sub.2 dosed. A temperature sensor [124] measures the flow temperature immediately after the orifice [122] to determine if the CO.sub.2 is in the liquid phase, gaseous phase or is a mixture of the two, recognizing that this has a major impact on the flow rate (e.g., at a certain pressure in the line and for a certain orifice, 25 SLPM gas vs. 1800 SLPM liquid). This post-orifice sensor is used to determine which phase (liquid or gas) is in the line and change the equation settings between liquid and gas, or mixed liquid and gas, to calculate the instantaneous flow rate. Integrating the flow over time allows the total flow to be calculated. The density of liquid is approximately 500 times greater than that of gas; therefore there is a drastic difference between the flow rate of 100% liquid and 100% gas. One or more pressure sensors (gauges) distal to the orifice may also be included (not shown), especially if the orifice opens into a conduit of sufficient length that the pressure immediately after the orifice is not atmospheric, so that calculations may be adjusted based on actual pressure distal to the orifice.
Further inputs and outputs can be used, as desired or suggested by the intended use of the system. For example, when used as a carbon dioxide delivery system for a concrete production facility, an operator can interact with the PLC of the carbon dioxide delivery system with a human machine interface (HMI) [132], which can be any suitable HMI, for example a touch screen. The operator can perform any suitable operation to send input to the delivery system PLC, for example by selecting a recipe using the HMI touch screen. The input could cause the delivery system PLC to issue the appropriate commands to, e.g., fill the headspace of a concrete mixer with carbon dioxide, then reduce the flow rate to take up the remaining mixing time to achieve the desired CO.sub.2 dose. The carbon dioxide delivery cycle and the mixing cycle can be synchronized by using signals from the concrete facility's process PLC [134], which can be input to the delivery system PLC [128].
In certain embodiments, the carbon dioxide amount to be delivered is a predetermined amount and the carbon dioxide delivery system opens and closes the appropriate valves based on flow rate and time. In certain embodiments additional, or alternative, inputs are used to modify the flow of carbon dioxide, for example, based on inputs from the concrete mixing operation. Thus, for example, the system can use input from one or more sensors [136, 138, 140] to modify the flow rate and mix time. For example, these can be CO2 sensors located at leak points outside the mixer that detect CO2 concentration, and if the CO2 concentration and/or rate of change of CO2 concentration, passes a certain threshold or some other parameter, the flow of carbon dioxide is modulated, e.g., reduced or ceased. Such CO2 sensors could be an important part of the dosing logic in a precast system, e.g., a masonry mixer injection system, but would likely mainly be present for safety in, e.g., ready-mix operations. It can alternatively or additionally include a mixer temperature sensor if the temperature of the concrete mixer can be used as feedback. It can alternatively or additionally include a concrete rheology measurement sensor. The sensors can shut the system off if the sensors measure a property that crosses a set threshold or other parameter. The system can also be run in manual mode and be set at a flow rate and then turned on for a given period of time.
In certain embodiments, the invention provides compositions and methods for carbonation of concrete mixes or components of concrete where the carbon dioxide is delivered as described herein and, optionally, the flow rate and total amount of carbon dioxide delivered to the mix is determined as described herein.
Cement mix operations are commonly performed to provide cement mixes (concrete) for use in a variety of applications, the most common of which is as a building material. Such operations include precast operations, in which a concrete structure is formed in a mold from the cement mix and undergoes some degree of hardening before transport and use at a location separate from the mix location, and ready mix operations, in which the concrete ingredients are supplied at one location and generally mixed in a transportable mixer, such as the drum of a ready mix truck, and transported to a second location, where the wet mix is used, typically by being poured or pumped into a temporary mold. Precast operations can be either a dry cast operation or a wet cast operation, whereas ready mix operations are wet cast. Any other operation in which a concrete mix is produced in a mixer and exposed to carbon dioxide during mixing is also subject to the methods and compositions of the invention. By “exposed to carbon dioxide” and similar phrases, as used herein, is meant exposure of the concrete mix to carbon dioxide at a concentration above that found in the atmosphere; usually at least 10-fold higher than atmospheric concentrations. Commercial sources of carbon dioxide of suitable purity are well-known. In certain embodiment, the carbon dioxide is 95-100% pure. The carbon dioxide may be commercially supplied high purity carbon dioxide. In this case, the commercial carbon dioxide may be sourced from a supplier that processes spent flue gasses or other waste carbon dioxide so that sequestering the carbon dioxide in the cement mix, e.g., hydraulic cement mix sequesters carbon dioxide that would otherwise be a greenhouse gas emission.
The methods in certain embodiments are characterized by contacting carbon dioxide with wet cement binder, e.g., hydraulic cement, in a mixer at any stage of the mixing, such as during mixing of the cement with water, or during the mixing of wetted cement with other materials, or both. The cement may be any cement, e.g., hydraulic cement capable of producing reaction products with carbon dioxide. For example, in certain embodiments the cement includes or is substantially all Portland cement, as that term is understood in the art. The cement may be combined in the mixer with other materials, such as aggregates, to form a cement-aggregate mixture, such as mortar or concrete. The carbon dioxide may be added before, during, or after the addition of the other materials besides the cement and the water. In addition or alternatively, in certain embodiments the water itself may be carbonated, i.e., contain dissolved carbon dioxide.
In certain embodiments, the carbon dioxide is contacted with the cement mix, e.g., hydraulic cement mix during mixing by contact with the surface of the mixing cement mix, e.g., hydraulic cement mix, that is, it is released from an opening or openings that is/are positioned so that the carbon dioxide is initially contacted over the surface of the concrete. As used herein, “contacted with the surface of the cement mix” and similar phrases encompasses embodiments in which the opening is close enough to the surface that there may be occasional contact with the surface of the mixing concrete and even temporary submersion under the surface, so long as the average distance of the opening from the surface is such that, on average, the carbon dioxide released is contacted with the surface and not underneath the surface. Without being bound by theory, it is believed that the carbon dioxide contacted with the surface of the cement mix, e.g., hydraulic cement mix dissolves and/or reacts in the water, and is then subsumed beneath the surface by the mixing process, which then exposes different cement mix, e.g., cement mix, to be contacted, and that this process continues for as long as the wetted hydraulic cement is exposed to the carbon dioxide. It will be appreciated that the process of dissolution and/or reaction may continue after the flow of carbon dioxide is halted, since carbon dioxide will likely remain in the gas mixture in contact with the cement mix, e.g., hydraulic cement mix. In embodiments in which liquid carbon dioxide is used to produce gaseous and solid carbon dioxide, the solid carbon dioxide will sublimate and continue to deliver gaseous carbon dioxide to the cement mix, e.g., hydraulic cement mix after the flow of liquid carbon dioxide has ceased. This is particularly useful in ready mix truck operations, where there may be insufficient time at the batching facility to allow uptake of the desired amount of carbon dioxide; the use of liquid carbon dioxide which converts to gaseous and solid carbon dioxide allow more carbon dioxide to be delivered to the mix even after the truck leaves the batching facility. It will be appreciated that the dissolution of the carbon dioxide in the mix water, and its reaction with components of the concrete mix to produce reaction products, such as intermediates and final reaction products, will, in general, continue after mixing of the concrete materials and carbon dioxide has stopped, that is, will not be complete even after, e.g., the concrete mix is poured or otherwise used at a job site. In other words, mixing is halted before a chemical reaction between the carbon dioxide and the concrete materials is complete.
The carbon dioxide may be contacted with the cement mix, e.g., hydraulic cement mix such that it is present during mixing by any suitable system or apparatus. In certain embodiments, gaseous or liquid carbon dioxide is supplied via one or more conduits that contain one or more openings positioned to supply the carbon dioxide to the surface of the mixing cement mix, e.g., hydraulic cement mix. The conduit and opening may be as simple as a tube, e.g., a flexible tube with an open end. The conduit may be sufficiently flexible so as to allow for movement of various components of the cement mix, e.g., hydraulic cement mixing apparatus, the conduit opening, and the like, and/or sufficiently flexible to be added to an existing system as a retrofit. On the other hand, the conduit may be sufficiently rigid, or tied-off, or both, to insure that it does not interfere with any moving part of the cement mix, e.g., hydraulic cement mixing apparatus. In certain embodiments, part of the conduit can be used for supplying other ingredients to the cement mix, e.g., water, and configured such that either the other ingredient or carbon dioxide flows through the conduit, e.g., by means of a T-junction.
Carbon dioxide may also be delivered to the cement mix, e.g., hydraulic cement mix as part of the mix water, i.e., dissolved in some or all of the mix water. Methods of charging water with carbon dioxide are well-known, such as the use of technology available in the soda industry. Some or all of the carbon dioxide to be used may be delivered this way. The mix water may be charged to any desired concentration of carbon dioxide achievable with the available technology, such as at least 1, 2, 4, 6, 8, 10, 12, 14, or 16 g of carbon dioxide/L of water, and/or not more than 2, 4, 6, 8, 10, 12, 14, 18, 20, 22, or 24 g of carbon dioxide/L of water, for example 1-12, 2-12, 1-10, 2-10, 4-12, 4-10, 6-12, 6-10, 8-12, or 8-10 g of carbon dioxide/L of water. It will be appreciated that the amount of carbon dioxide dissolved in the mix water is a function of the pressure of the carbon dioxide and the temperature of the mix water; at lower temperatures, far more carbon dioxide can be dissolved than at higher temperatures. Without being bound by theory, it is thought that the mix water so charged contacts the cement mix, e.g., hydraulic cement mix and the carbon dioxide contained therein reacts very quickly with components of the cement mix, e.g., hydraulic cement mix, leaving the water available to dissolve additional carbon dioxide that may be added to the system, e.g., in gaseous form.
In certain embodiments, a cement mix such as a concrete mix is carbonated with carbon dioxide supplied as carbonated water, for example, in the drum of a ready mix truck. The carbonated water serves as a portion of the total mix water for the particular mix. The carbonated water can provide at least 1, 5, 10, 15, 20, 25, 30, 35, 40, 50, 60, 70, 80, or 90% of the total mix water, and/or no more than 10, 20, 30, 40, 50, 60, 70, 80, 90, 95, or 100% of the mix water. The carbonated water may be added at the start of mixing of the cement mix, or it may be added after the start of mixing. It can be added as one batch or in stages, for example, as 2, 3, 4, 5 or more than 5 batches. The batches may be equal in volume or different volumes, and have the same carbonation or different carbonations. In certain embodiments, the carbonated water is less than 100% of the total mix water, for example, less than 80%, or less than 70%, or less than 60%, or less than 50%. In certain of these embodiments, embodiments, non-carbonated water is first added to the mix, and the cement mix, e.g., concrete, is allowed to mix for a certain period before carbonated water is added, for example, for at least 5, 10, 15, 20, 30, 40, or 50 seconds, or at least 1, 2, 5, 10, 15, 20, 25, 30, 40, 50, or 60 minutes before addition of the carbonated water, and/or not more than 10, 15, 20, 30, 40, or 50 seconds, or 1, 2, 5, 10, 15, 20, 25, 30, 40, 50, 60, 90, 120, 240, or 360 minutes before addition of carbonated water. The carbonated water may contribute all of the carbon dioxide used to carbonate a cement mix, e.g., concrete (neglecting atmospheric carbon dioxide); this is especially true for low-dose carbonation, for example, carbonation with a dose of carbon dioxide of less than 1.5% bwc, or less than 1.0% bwc, or less than 0.8% bwc. The carbonated water may contribute part of the carbon dioxide used to carbonate a cement mix, e.g., concrete, such as not more than 10, 20, 30, 40, 50, 60, 70, 80, 90 or 95% of the carbon dioxide and/or at least 5, 10, 20, 30, 40, 50, 60, 70, 80, or 90% of the carbon dioxide. In certain embodiments, the remaining carbon dioxide is supplied as a gas. In certain embodiments, the remaining carbon dioxide is supplied as a solid. In certain embodiments, the remaining carbon dioxide is supplied as a mixture of a gas and a solid, for example, carbon dioxide delivered to an orifice directed into the mixer in liquid form, which becomes gas and solid when passing through the orifice. The exact mix of carbonated water and other carbon dioxide source will be determined based on the dose of carbon dioxide to be delivered and other factors, such as delivery time, temperature (lower temperatures allow greater carbon dioxide delivery via carbonated water), and the like. The carbonated water may be produced by any suitable method, as described herein, and may be delivered to the mixer, e.g., the ready mix truck, via the normal water line or via a dedicated line. In certain embodiments carbonated water is delivered to the mix at the batch site and/or during transportation, and an optional dose is delivered at the job site, depending on the characteristics of the mix measured at the job site. The use of carbonated water can allow for very high efficiencies of carbon dioxide uptake, as well as precise control of dosage, so that highly efficient and reproducible carbon dioxide dosing can be achieved. In certain embodiments in which carbonated mix water is used, the efficiency of carbonation can be greater than 60, 70, 80, 90, or even 95%, even when operating in mixers, such as ready mix drums, which are open to the atmosphere.
Carbon dioxide may be introduced to the mixer such that it contacts the hydraulic cement mix (concrete) before, during, or after addition of water, or any combination thereof, so long as it is present during some portion of the mixing of some or all of the cement mix, e.g., hydraulic cement mix. In certain embodiments, the carbon dioxide is introduced during a certain stage or stages of mixing. In certain embodiments, the carbon dioxide is introduced to a cement mix, e.g., hydraulic cement mix during mixing at one stage only. In certain embodiments, the carbon dioxide is introduced during one stage of water addition, followed by a second stage of water addition. In certain embodiments, the carbon dioxide is introduced to one portion of cement mix, e.g., hydraulic cement mix, followed by addition of one or more additional portions of cement mix, e.g., hydraulic cement mix.
In certain embodiments, carbon dioxide is delivered to a flowable concrete mix, for example, in a mixer, e.g., while the concrete mix is mixing, where the amount of carbon delivered to the concrete mix is determined from parameters including pressure and temperature measurements of the carbon dioxide as it is delivered to the concrete mix. The carbon dioxide can be delivered, at least in part, as a mixture of gaseous and solid carbon dioxide produced by exposing liquid carbon dioxide to a pressure drop sufficient to induce formation of gaseous and solid carbon dioxide, for example, by passing liquid carbon dioxide through an orifice whose downstream, or distal, end is at atmospheric pressure; a first temperature measurement and a pressure measurement can be taken of the liquid carbon dioxide on the upstream, or proximal, side of the orifice and a second temperature measurement can be taken of carbon dioxide exiting the orifice, i.e., on the downstream or distal side of the orifice. Apparatus and methods for delivery of the carbon dioxide, determining the temperatures and pressure, and determining flow rates and/or amounts of carbon dioxide are as described herein. In these embodiments, it is not necessary to use other methods of determining flow and/or total amount of carbon dioxide delivered, such as mass flow controllers and/or weights or masses of carbon dioxide containers.
In certain embodiments, a predetermined amount of carbon dioxide is added to the concrete mix, and the flow of carbon dioxide is halted when the amount of carbon dioxide delivered to the mix equals or exceeds the predetermined amount. In certain embodiments, one or more additional characteristics of the concrete mix or its environment are measured and carbon dioxide delivery can be modulated based on the amount of carbon dioxide delivered in combination with the one or more additional characteristics. The concrete mix can be a wet mix, such as used in ready-mix applications and certain wet mix precast operations, or a dry mix, such as used in certain dry mix precast operations. The mixer for the concrete mix can be a stationary mixer, such as a mixer in a precast concrete operation, or a transportable mixer, such as a drum of a ready-mix truck.
The predetermined dose of carbon dioxide may be any suitable dose, generally expressed as a % by weight cement (bwc). In certain embodiments, the dose or amount of carbon dioxide of carbon dioxide that is determined by the methods and compositions of the invention is 0.01-5% bwc, for example, 0.05-4% bwc, in some cases 0.05-2% bwc. In certain embodiments, a low dose of carbon dioxide is delivered, e.g., an amount less than or equal to 2% bwc, or 1.5% bwc, or 1% bwc. In certain embodiments, the predetermined amount of carbon dioxide to be delivered to the concrete mix may be not more than 1.5%, 1.2%, 1%, 0.8%, 0.7%, 0.6%, 0.5%, 0.4%, 0.3%, 0.2%, 0.1%, or 0.05% bwc and/or at least 0.01, 0.05, 0.1, 0.2, 0.3, 0.4, 0.5, 0.6, 0.7, 0.8, 0.9, 1.0, or 1.2% bwc, such as a dose of 0.01-1.5%, 0.01-1.2%, 0.01-1%, 0.01-0.8%, 0.01-0.6%, 0.01-0.5%, 0.01-0.4%, 0.01-0.3%, 0.01-0.2%, or 0.01-0.1% bwc, or a dose of 0.02-1.5%, 0.02-1.2%, 0.02-1%, 0.02-0.8%, 0.02-0.6%, 0.02-0.5%, 0.02-0.4%, 0.02-0.3%, 0.02-0.2%, or 0.02-0.1% bwc, or a dose of 0.04-1.5%, 0.04-1.2%, 0.04-1%, 0.04-0.8%, 0.04-0.6%, 0.04-0.5%, 0.04-0.4%, 0.04-0.3%, 0.04-0.2%, or 0.04-0.1% bwc, or a dose of 0.06-1.5%, 0.06-1.2%, 0.06-1%, 0.06-0.8%, 0.06-0.6%, 0.06-0.5%, 0.06-0.4%, 0.06-0.3%, 0.06-0.2%, or 0.06-0.1% bwc, or a dose of 0.1-1.5%, 0.1-1.2%, 0.1-1%, 0.1-0.8%, 0.1-0.6%, 0.1-0.5%, 0.1-0.4%, 0.1-0.3%, or 0.1-0.2% bwc. Any other suitable dose may also be used.
The carbon dioxide, e.g., gaseous carbon dioxide or liquid carbon dioxide, is introduced in the mixing cement mix, e.g., hydraulic cement mix, for example, in the first stage of mixing, at a certain flow rate and for a certain duration in order to achieve a total carbon dioxide exposure. The flow rate and duration will depend on, e.g., the purity of the carbon dioxide gas, the total batch size for the cement mix, e.g., hydraulic cement mix and the desired level of carbonation of the mix. A metering system and adjustable valve or valves in the one or more conduits may be used to monitor and adjust flow rates. In some cases, the duration of carbon dioxide flow to provide exposure is at or below a maximum time, such as at or below 100, 50, 20, 15, 10, 8, 5, 4, 3, 2, or one minute. In certain embodiments, the duration of carbon dioxide flow is less than or equal to 5 minutes. In certain embodiments, the duration of carbon dioxide flow is less than or equal to 4 minutes. In certain embodiments, the duration of carbon dioxide flow is less than or equal to 3 minutes. In certain embodiments, the duration of carbon dioxide flow is less than or equal to 2 minutes. In certain embodiments, the duration of carbon dioxide flow is less than or equal to 1 minutes. In some cases, the duration of carbon dioxide flow to provide exposure is within a range of times, such as 0.5-20 min, or 0.5-15 min, or 0.5-10 min, or 0.5-8 min, or 0.5-5 min, or 0.5-4 min, or 0.5-3 min, or 0.5-2 min, or 0.5-1 min, or 1-20 min, or 1-15 min, or 1-10 min, or 1-8 min, or 1-5 min, or 1-4 min, or 1-3 min, or 1-2 min. In certain embodiments, the duration of carbon dioxide flow is 0.5-5 min. In certain embodiments, the duration of carbon dioxide flow is 0.5-4 min. In certain embodiments, the duration of carbon dioxide flow is 0.5-3 min. In certain embodiments, the duration of carbon dioxide flow is 1-5 min. In certain embodiments, the duration of carbon dioxide flow is 1-4 min. In certain embodiments, the duration of carbon dioxide flow is 1-3 min. In certain embodiments, the duration of carbon dioxide flow is 1-2 min.
In low dose carbonation, as in all cement mix, e.g., concrete, carbonation, various factors may be manipulated to produce optimal or desired results. These include one or more of: time after beginning of mixing at which carbon dioxide is applied; number of doses of carbon dioxide; rate at which carbon dioxide is supplied to the mixing chamber; form of the carbon dioxide (gas, solid, and/or dissolved in water); and the like. Mixing is said to have commenced upon addition of the first aliquot of water to the cement-containing mix. It will be appreciated that in certain instances, components of a concrete mix, e.g., aggregate, may be wet and that “the first mix water” may be the water on the aggregate. Carbon dioxide can be supplied to a mix before the first addition of water, for example by flooding a chamber or head space with carbon dioxide before water addition, but in this case the application of carbon dioxide is considered to occur when the first water is added, since virtually no reaction will occur until the carbon dioxide dissolves in the mix water. Thus, in certain embodiments, carbon dioxide is applied to the mix at 0 minutes, that is, carbon dioxide is present to the mix chamber when the first mix water is supplied, or supplying carbon dioxide to the mix chamber commences when the first mix water is applied, or both. In certain embodiments, carbon dioxide is applied at least 1, 2, 5, 10, 15, 20, 30, 40, 50, 60, 70, 80, or 90 minutes after mixing commences, and/or not more than 2, 5, 10, 15, 20, 30, 40, 50, 60, 70, 80, 90, 120, or 180 minutes after mixing commences. For example, in the case of carbon dioxide supplied to a concrete mix in a ready mix truck, the mix components, including at least part of the mix water, may be added to the truck, and it may be desirable that carbon dioxide addition not commence until at least 2, 3 or 4 minutes or more after mixing has commenced. Such addition could occur, e.g., at a wash station, where the driver stops to wash the truck before commencing delivery; the truck is usually stopped at the wash station for at least 5-10 minutes, and an on-site carbon dioxide delivery system can be used to supply carbon dioxide to the drum of the truck during the wash station stop. Part or all of the dose of carbon dioxide can be delivered in this manner, for example by delivering carbon dioxide to the truck through the water line (though any suitable means may be used); in embodiments where a carbon dioxide source is attached to the truck there may be some mechanism to remind the driver to detach it before departing, such as an alarm. Alternatively, or additionally, the desirable time for addition of carbon dioxide to the mix may be later in the mix time, such as at a time that the truck is normally en route to the job site, or at the job site. In this case, a portable source of carbon dioxide may be attached to the truck, with suitable valving and tubing, so as to deliver one or more doses of carbon dioxide to the drum of the truck at a later time, such as at least 15, 30, or 60 minutes after mixing commences. A controller, which may be self-contained or may be remotely activated and which may send signals to a remote site regarding dosing and other information, may be included in the system so that dosing commences at a predetermined time after mixing commences and continues for a predetermined time, or continues until some predetermined characteristic or characteristics of the concrete mix is detected. Alternatively, the time and/or duration of dosing may be manually controlled, or subject to manual override. The carbon dioxide source can be as simple as a pressurized tank of gaseous carbon dioxide, which can be topped off periodically, for example when the truck returns to the batching site, to ensure a sufficient supply of carbon dioxide for any ensuing round of carbonation, e.g., without the need to ascertain carbon dioxide levels in the tank. In these embodiments, some or all of the carbonation may occur at the job site, for example, based on determination of one or more characteristics of the concrete.
The rate of delivery of the carbon dioxide may be any desired rate and the rate may be controlled by any suitable means. A slower rate of delivery may be desired, especially in wet mix operations such as ready mix operations, where the higher w/c ratio is known to slow carbonation compared to lower w/c operations, e.g., some precast operations. Thus, although a single dose may be used, in some cases the total dose of carbon dioxide is divided into two or more smaller doses. Thus, the carbon dioxide may be delivered as a single dose, or as multiple doses, for example, as at least 2, 3, 4, 5, 6, 7, 8, 9, or 10 doses, and/or not more than 3, 4, 5, 6, 7, 8, 9, 10, 12, 15, or 20 doses; such as 2-10 doses, or 2-5 doses. Each dose may be equal in size to the others or different, and the interval between doses may be timed equally or not, as desired. The exact number and size of the doses may be predetermined, or it may be dictated by one or more characteristics of the mix that are monitored. The carbon dioxide may be in any suitable form, such as gas, or a gas/solid mix. Any other suitable division of doses may also be used.
The dose chosen for a given mix, for example, to produce a desired increase in early strength or set, or to produce an optimal increase in early strength or set, can be dependent on the mix and especially on the cement used in the mix. In certain embodiments the invention provides a method of carbonating a cement mix, e.g., concrete, during mixing, where carbon dioxide is added to the mix at a predetermined dose, where the predetermined dose is determined by testing one or more components of the mix, for example, the concrete, to determine a dose or a range of doses that produces optimal or desired increase in early strength and/or set. It will be appreciated that, in the case of low dose carbonation, a carbonation value may not be able to be determined, and that strength tests can require multiple samples and days to weeks to complete. Thus, in some embodiments, a predetermined dose of carbon dioxide is determined using an alternative marker, such as isothermal calorimetry. Heat release during hydration is related to two somewhat overlapping peaks. The main heat release is related to the hydration of silicates, while a second heat release, observed as a hump on the downslope of the silicate peak, is associated with the hydration of the aluminates. Isothermal calorimetry testing is easy to carry out in mortar or even cement paste with very minimal sample preparation compared to the making of concrete samples, thus allowing for a rapid and convenient method of determining an optimal CO2 dose and timing for a given cement, by testing a range of doses and delivery times. The results obtained are either in the form of heat flow rate over time (also referred to as power vs. time herein), which describes the rate of cement hydration, or in the form of heat of hydration over time, which is the integrated heat flow rate (also referred to as energy vs. time herein).
The methods and compositions of the invention allow for very high levels of efficiency of uptake of carbon dioxide into the mixing concrete, where the efficiency of uptake is the ratio of carbon dioxide that remains in the mixing concrete as stable reaction products to the total amount of carbon dioxide to which the mixing concrete is exposed. In certain embodiments, the efficiency of carbon dioxide uptake, for example, in ready mix trucks at full capacity during a period of operation at a batching plant, such as averaged over all trucks receiving carbon dioxide in a single day, is at least 40, 50, 60, 70, 80, 90, 95, 96, 97, 98, 99, or 99%, or 40-100, 50-100, 60-100, 70-100, 80-100, 90-100, 40-99, 50-99, 60-99, 70-99, 80-99, or 90-99%. This is especially true in open mixers, e.g., the drum of a ready-mix truck; such efficiencies may be achieved by the positioning of the conduit to deliver carbon to the mixing concrete in the drum of the truck, other characteristics of the methods and compositions of the invention described herein, or a combination thereof.
Part of an apparatus of the invention can be, for example a first controller, e.g., a first PLC, that controls the carbon dioxide delivery, which may receive one or more signals from the mix operation and/or one or more signals from a second controller, for example a second PLC, for the mix system, or both, that indicates a change in an aspect of the mix operation is occurring. The signal or signals may be used, e.g., to time the initiation of carbon dioxide delivery. In embodiments in which a predetermined amount of carbon dioxide is to be delivered, the amount of carbon dioxide delivered is then determined from the time that delivery starts from parameters including, e.g., pressure and temperature measurements for the carbon dioxide as described herein, and is halted when the predetermined amount is reached.
For example, in a stationary mixer system, the first controller may receive a signal from the proximity switch or the customer PLC indicating cement gate opening. This signal may be used to time the initiation of carbon dioxide delivery. In embodiments where a predetermined amount of carbon dioxide is to be added to the concrete mix, flow rate and total amount of carbon dioxide delivered can be determined as described herein, until the predetermined amount of carbon dioxide is reached and the first controller causes carbon dioxide delivery to cease.
An alternative method may be used, for example, when a predetermined amount of carbon dioxide is to be delivered to a transportable mixer, such as the drum of a ready-mix truck. Instead of getting a signal from the proximity switch or the customer PLC indicating cement gate opening, the first controller, e.g., PLC, receives a signal, e.g., a 120 VAC signal, from the ready-mix batching system indicating that carbon dioxide delivery to the drum of the truck is to be initiated. The signal is continuous as long as carbon dioxide delivery is to continue, and carbon dioxide delivery stops when the signal is lost.
The first controller determines flow rate and amount carbon dioxide delivered, and outputs a signal, e.g., a 24 VDC pulse for every incremental amount of CO2 delivered, for example, for every x kg of CO2 delivered to a drum of a ready-mix truck. The ready-mix batching system counts the number of pulses and stops the 120 VAC signal once it reaches the desired number of pulses that corresponds to the desired dose of CO2, thus ending CO2 delivery to the truck. The result is that the system can deliver, e.g., full liquid at maximum flow to the orifice without having to turn the valve off and on. During the operation of the liquid system the gas and liquid valves can be opened and closed to maintain a set average flow rate over a given amount of time. In this case, once the liquid valve is opened, it remains open until the desired dose (mass) has been achieved, then shuts off using the normal valve sequence as outlined herein. This procedure simplifies carbon dioxide delivery because flow is determined by the equations above, with just a few measurements needed. There is also no need for recipes in the first controller, since dosing information can be drawn from the ready-mix batching system controller, e.g., PLC. A light may be added that illuminates when carbon dioxide delivery is occurring. One or more sensors in the vicinity of the drum can be used to monitor carbon dioxide concentrations for safety purposes and carbon dioxide delivery can be halted if a threshold is exceeded; an alarm can also be delivered, such as an alarm sound, or light, or both.
The dosing may be started at any suitable time before, during, or after the mixing of the concrete begins, that is, after water is added so that the cement in the concrete mix begins hydration, for example, immediately upon addition of water, or after at least 10, 20, 30, 40, or 50 seconds, or at least 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 12, 15, or 20 minutes after addition of water.
One or more admixtures may also be added to the concrete mix, before, during, and/or after the addition of the carbon dioxide. In certain cases, the addition of carbon dioxide alters the properties of the concrete mix in such a manner that it is desirable to add an admixture to the mix to counteract the effect of the carbon dioxide; for example, in certain cases, addition of carbon dioxide can reduce the flowability of the concrete mix and it is desirable to add an admixture that returns flowability to a desired level. In certain embodiments, one or more admixtures, described more fully below, are added at a time and in a concentration so that flowability of the final concrete mix is within 50, 40, 30, 20 15, 10, 8, 5, 4, 3, 2, or 1% of the flowability that would be achieved without the addition of carbon dioxide, or of a predetermined flowability. In certain embodiments, one or more admixtures, described more fully below, are added at a time and in a concentration so that flowability of the final concrete mix is within 20% of the flowability that would be achieved without the addition of carbon dioxide, or a predetermined flowability. In certain embodiments, one or more admixtures, described more fully below, are added at a time and in a concentration so that flowability of the final concrete mix is within 10% of the flowability that would be achieved without the addition of carbon dioxide, or a predetermined flowability. In certain embodiments, one or more admixtures, described more fully below, are added at a time and in a concentration so that flowability of the final concrete mix is within 5% of the flowability that would be achieved without the addition of carbon dioxide, or a predetermined flowability. In certain embodiments, one or more admixtures, described more fully below, are added at a time and in a concentration so that flowability of the final concrete mix is within 2% of the flowability that would be achieved without the addition of carbon dioxide, or a predetermined flowability. In certain embodiments, one or more admixtures, described more fully below, are added at a time and in a concentration so that flowability of the final concrete mix is within 1-50%, or 1-20%, or 1-10%, or 1-5%, or 2-50%, or 2-20%, or 2-10%, or 2-5% of the flowability that would be achieved without the addition of carbon dioxide, or a predetermined flowability. Any suitable measurement method for determining flowability may be used, such as the well-known slump test.
If one or more admixtures is used, any suitable admixture may be used with useful admixtures include set retarders. Set retarders include carbohydrates, i.e., saccharides, such as sugars, e.g., fructose, glucose, and sucrose, and sugar acids/bases and their salts, such as sodium gluconate and sodium glucoheptonate; phosphonates, such as nitrilotri(methylphosphonic acid), 2-phosphonobutane-1,2,4-tricarboxylic acid; and chelating agents, such as EDTA, Citric Acid, and nitrilotriacetic acid. Other saccharides and saccharide-containing admixes of use in the invention include molasses and corn syrup. In certain embodiments, the admixture is sodium gluconate. Other exemplary admixtures that can be of use as set retarders include sodium sulfate, citric acid, BASF Pozzolith XR, firmed silica, colloidal silica, hydroxyethyl cellulose, hydroxypropyl cellulose, fly ash (as defined in ASTM C618), mineral oils (such as light naphthenic), hectorite clay, polyoxyalkylenes, natural gums, or mixtures thereof, polycarboxylate superplasticizers, naphthalene HRWR (high range water reducer). Additional set retarders that can be used include, but are not limited to an oxy-boron compound, lignin, a polyphosphonic acid, a carboxylic acid, a hydroxycarboxylic acid, polycarboxylic acid, hydroxylated carboxylic acid, such as fumaric, itaconic, malonic, borax, gluconic, and tartaric acid, lignosulfonates, ascorbic acid, isoascorbic acid, sulphonic acid-acrylic acid copolymer, and their corresponding salts, polyhydroxysilane, polyacrylamide. The admixture or admixtures may be added to any suitable final percentage (bwc), in some cases, the concentration is greater than 0.01%, 0.015%, 0.02%, 0.025%, 0.03%, 0.035%, 0.04%, 0.05%, 0.06%, 0.07%, 0.08%, 0.09%, 0.1%, 0.15%, 0.2%, 0.3%, 0.4%, or 0.5% bwc. The concentration may also be less than 2, 1.5, 1, 0.9, 0.8, 0.7, 0.6, 0.5, 0.4, 0.3, 0.2, or 0.1%. For example, a suitable range of dose, bwc, may be used, such as in the range of 0.01-0.5%, or 0.01-0.3%, or 0.01-0.2%, or 0.01-0.1%, or 0.01-1.0%, or 0.01-0.05%, or 0.05% to 5%, or 0.05% to 1%, or 0.05% to 0.5%, or 0.1% to 1%, or 0.1% to 0.8%, or 0.1% to 0.7% per weight of cement. The admixture may be added to a final percentage of greater than 0.01, 0.02, 0.03, 0.04, 0.05, 0.06, 0.07, 0.08, 0.09, 0.1, 0.15, 0.2, 0.3, 0.4, or 0.5%; in certain cases also less than 5, 4, 3, 2, 1, 0.9, 0.8, 0.7, 0.6, 0.5, 0.4, 0.3, 0.2, 0.1, 0.09, 0.08, 0.07, 0.06, 0.05, 0.04, 0.03, or 0.02%. For example, in certain embodiments, sodium gluconate is used as an admixture at a dose of between 0.01 and 1% bwc, or between 0.01 and 0.8%, or between 0.01 and 0.5%, or between 0.01 and 0.4% bwc, or between 0.01 and 0.3%, or between 0.01 and 0.2% bwc, or between 0.01 and 0.1%, or between 0.01 and 0.05%, or between 0.03 and 1% bwc, or between 0.03 and 0.8%, or between 0.03 and 0.5%, or between 0.03 and 0.4% bwc, or between 0.03 and 0.3%, or between 0.03 and 0.2% bwc, or between 0.03 and 0.1%, or between 0.03 and 0.08%, or between 0.05 and 1% bwc, or between 0.05 and 0.8%, or between 0.05 and 0.5%, or between 0.05 and 0.4% bwc, or between 0.05 and 0.3%, or between 0.05 and 0.2% bwc, or between 0.05 and 0.1%, or between 0.05 and 0.08%, or between 0.1 and 1% bwc, or between 0.1 and 0.8%, or between 0.1 and 0.5%, or between 0.1 and 0.4% bwc, or between 0.1 and 0.3%, or between 0.1 and 0.2% bwc. The sodium gluconate may be added before, during, or after carbonation of the mix, or any combination thereof, and may be added as one, two, three, four, or more than four divided doses. The carbohydrate or derivative may be added in two or more doses, such as one dose before carbonation and one dose during and/or after carbonation. In certain embodiments, calcium stearate is used as an admixture.
In certain embodiments, a second admixture is also used with the second admixture is a strength accelerator. In certain embodiments, a third admixture is also used. In certain embodiments, a fourth admixture is also used. In certain embodiments, one or more supplementary cementitious materials (SCMs) and/or cement replacements are added to the mix at the appropriate stage for the particular SCM or cement replacement. In certain embodiments, an SCM is used. Any suitable SCM or cement replacement may be used; exemplary SCMs include blast furnace slag, fly ash, silica fume, natural pozzolans (such as metakaolin, calcined shale, calcined clay, volcanic glass, zeolitic trass or tuffs, rice husk ash, diatomaceous earth, and calcined shale), and waste glass. Further cement replacements include interground limestone, recycled/waste plastic, scrap tires, municipal solid waste ash, wood ash, cement kiln dust, foundry sand, and the like. In certain embodiments, an SCM and/or cement replacement is added to the mix in an amount to provide 0.1-50%, or 1-50%, or 5-50%, or 10-50%, or 20-50%, or 1-40%, or 5-40%, or 10-50%, or 20-40% bwc. In certain embodiments, an SCM is used and the SCM is fly ash, slag, silica fume, or a naturual pozzolan. In certain embodiment, the SCM is fly ash. In certain embodiments, the SCM is slag.
It is well-known that addition of an SCM such as fly ash or slag to a cement mix, e.g., concrete mix, can retard early strength development; indeed, when weather becomes cold enough, the use of SCM in mixes is curtailed because the early strength development is sufficiently retarded as to make the use of the mix problematic. In addition, the maximum amount of SCM that may be added to a mix can be limited by its effect on early strength development. The present inventors have found that even very low doses of carbon dioxide, when added to a concrete mix containing SCM, can accelerate early strength development and thus could allow such mixes to be used under circumstances where they otherwise might not be used, e.g., in cold weather, or in greater amounts, thus extending the usefulness of such mixes, such as extending the useful season for such mixes, or increasing the proportion of SCM in a given mix, or both.
In certain embodiments the invention provides methods and compositions for the expanding the range of conditions under which an SCM may be used in a concrete mix by carbonating the mix. The range of conditions may include the temperature at which the SCM-containing mix may be used, or the amount of SCM that may be added while maintaining adequate early strength development, or the early strength for a given amount of SCM in a mix.
In certain embodiments, the invention provides a method for decreasing the minimum temperature at which an SCM-concrete mix may be used, thus increasing the overall acceptable temperature range for the SCM-concrete mix, by exposing the SCM-concrete mix to a dose of carbon dioxide sufficient to modulate, e.g., accelerate, early strength development and/or set of the mix to a level at which the mix may be used at a temperature below that at which it could have been used without the carbon dioxide exposure. The dose can be such that the early strength development of the mix allows its use in a desired manner at a temperature that is at least 1, 2, 3, 4, 5, 6, 8, 9, or 10° C. below the temperature at which it could be used without the carbon dioxide treatment and/or not more than 2, 3, 4, 5, 6, 8, 9, 10, or 12° C. below the temperature at which it could be used without the carbon dioxide treatment. The dose of carbon dioxide added to the mix to achieve the desired increase in early strength development can be not more than 2.0, 1.5, 1.2, 1.0, 0.9, 0.8, 0.7, 0.6, 0.5, 0.4, 0.3, 0.2, 0.1, or 0.05% carbon dioxide bwc. The dose can be such that the early strength development of the mix, e.g., the strength at 8, 12, 16, 20, or 24 hours, or any other suitable time point for early strength development, is, on average, at least 1, 2, 5, 7, 10, 12, 15, 20, or 25% greater than the strength without the carbon dioxide dose, and is sufficient for the use for which the mix is intended. In certain embodiments, an alternative or additional marker other than early strength development, such as a value from calorimetry as described elsewhere herein, may be used instead of or in addition to early strength measurements, for example, to determine the desired or optimal dose of carbon dioxide and/or dosing conditions. The carbon dioxide may be delivered as a single dose or multiple doses, and at any suitable rate or in any suitable form, as described elsewhere herein. The SCM can be any suitable SCM. In certain embodiments, the SCM is fly ash. In certain embodiments, the SCM is slag. In certain embodiments, the SCM-concrete mix is delivered to a job site in a ready mix truck, and the carbon dioxide is applied to the mix at the batching site, en route to the job site, or at the job site, or any combination thereof. In certain embodiments, the carbon dioxide is gaseous carbon dioxide. In certain embodiments, the carbon dioxide is dissolved in mix water. In certain embodiments, the carbon dioxide is solid carbon dioxide. In certain embodiments, a combination of gaseous carbon dioxide and carbon dioxide dissolved in mix water is used.
In certain embodiments, the invention provides a method for increasing the maximum amount (proportion) of SCM that may be used in an SCM-concrete mix, thus increasing the overall acceptable range of amounts (proportions) of SCM for the SCM-concrete mix, by exposing an SCM-concrete mix that contains a proportion of SCM that would normally be higher than the acceptable proportion due to effects on early strength development, to a dose of carbon dioxide sufficient to modulate, e.g., accelerate, early strength development of the mix to a level at which the mix may be used for its normal purposes. In certain embodiments, the maximum acceptable proportion of SCM in the mix is increased by carbonation by at least 0.5, 1, 1.5, 2, 2.5, 3, 3.5, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, or 20% bwc and/or not more than 1, 1.5, 2, 2.5, 3, 3.5, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, or 25% bwc, over the maximum acceptable proportion of SCM without carbonation. The dose of carbon dioxide to the mix can be not more than 2.0, 1.5, 1.2, 1.0, 0.9, 0.8, 0.7, 0.6, 0.5, 0.4, 0.3, 0.2, 0.1, or 0.05% carbon dioxide bwc, and/or not less than 2.5, 2.0, 1.5, 1.2, 1.0, 0.9, 0.8, 0.7, 0.6, 0.5, 0.4, 0.3, 0.2, or 0.1% carbon dioxide bwc. The SCM can comprises at least 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 12, 15, 20, or 30% of the mix, and/or not less than 2, 3, 4, 5, 6, 7, 8, 9, 10, 12, 15, 20, 30, 40, or 50% of the mix. The dose can be such that the early strength development of the mix, e.g., the strength at 8, 12, 16, 20, or 24 hours, or any other suitable time point for early strength development, is, on average, at least 1, 2, 5, 7, 10, 12, 15, 20, or 25% greater than the strength without the carbon dioxide dose. In certain embodiments, an alternative or additional marker other than early strength development, such as a value from calorimetry as described elsewhere herein, may be used instead of or in addition to early strength measurements, for example, to determine the desired or optimal dose of carbon dioxide and/or dosing conditions. The carbon dioxide may be delivered as a single dose or multiple doses, and at any suitable rate or in any suitable form, as described elsewhere herein. The SCM can be any suitable SCM. In certain embodiments, the SCM is fly ash. In certain embodiments, the SCM is slag. In certain embodiments, the SCM-concrete mix is delivered to a job site in a ready mix truck, and the carbon dioxide is applied to the mix at the batching site, en route to the job site, or at the job site, or any combination thereof. In certain embodiments, the carbon dioxide is gaseous carbon dioxide. In certain embodiments, the carbon dioxide is dissolved in mix water. In certain embodiments, the carbon dioxide is solid carbon dioxide. In certain embodiments, a combination of gaseous carbon dioxide and carbon dioxide dissolved in mix water is used.
In certain embodiments, the invention provides a method for accelerating the early strength development of an SCM-concrete mix, thus accelerating aspects of a job in which the SCM-concrete mix is used that require a certain strength before a next step may be taken (such as removing molds, adding a level of concrete, and the like), by exposing the SCM-concrete mix to a dose of carbon dioxide sufficient to modulate, e.g., accelerate, early strength development of the mix to a level at which the aspect of the job may be accelerated. The dose of carbon dioxide to the mix can be not more than 2.0, 1.5, 1.2, 1.0, 0.9, 0.8, 0.7, 0.6, 0.5, 0.4, 0.3, 0.2, 0.1, or 0.05% carbon dioxide bwc, and/or not less than 2.5, 2.0, 1.5, 1.2, 1.0, 0.9, 0.8, 0.7, 0.6, 0.5, 0.4, 0.3, 0.2, or 0.1% carbon dioxide bwc. The dose can be such that the early strength development of the mix, e.g., the strength at 8, 12, 16, 20, or 24 hours, or any other suitable time point for early strength development, is, on average, at least 1, 2, 5, 7, 10, 12, 15, 20, 25, 30, 35, or 40% greater than the strength without the carbon dioxide dose. The SCM can comprises at least 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 12, 15, 20, or 30% of the mix, and/or not less than 2, 3, 4, 5, 6, 7, 8, 9, 10, 12, 15, 20, 30, 40, or 50% of the mix. In certain embodiments, an alternative or additional marker than early strength development, such as a value from calorimetry as described elsewhere herein, may be used instead of or in addition to early strength measurements, for example, to determine the desired or optimal dose of carbon dioxide and/or dosing conditions. The carbon dioxide may be delivered as a single dose or multiple doses, and at any suitable rate or in any suitable form, as described elsewhere herein. The SCM can be any suitable SCM. In certain embodiments, the SCM is fly ash. In certain embodiments, the SCM is slag. In certain embodiments, the SCM-concrete mix is delivered to a job site in a ready mix truck, and the carbon dioxide is applied to the mix at the batching site, en route to the job site, or at the job site, or any combination thereof. In certain embodiments, the carbon dioxide is gaseous carbon dioxide. In certain embodiments, the carbon dioxide is dissolved in mix water. In certain embodiments, the carbon dioxide is solid carbon dioxide. In certain embodiments, a combination of gaseous carbon dioxide and carbon dioxide dissolved in mix water is used.
In a ready-mix operation, the carbon dioxide may be delivered to the drum of the truck via a conduit, or lance or wand, that is positioned relative to the drum of each truck as it passes through the delivery site, e.g., the batching site, a wash station, or other suitable carbon dioxide delivery site. The lance can attached to the orifice as described herein, for example, at a NPT connection as shown in FIG. 1, and used to direct the carbon dioxide, such as mixture of solid and gaseous carbon dioxide, to a desired location in the drum. The lance is positioned so that carbon dioxide is delivered to the concrete mix in the drum of the truck. When carbon dioxide delivery is complete, the lance is moved as necessary to allow the truck to leave the delivery site and a new truck to enter the delivery site, then positioned as necessary for the next carbon dioxide delivery to the new truck. In general, it is preferable that the lance or wand be constructed of insulating materials so as to preserve the carbon dioxide in solid form and minimize sublimation to gaseous carbon dioxide, which improves efficiency of delivery of the carbon dioxide to the concrete mix.
When such a delivery system is used, the positioning of the conduit for the carbon dioxide so that the opening is in a certain position and attitude relative to the drum can be important; one aspect of some embodiments of the invention is positioning the wand, and/or an apparatus for doing so, to facilitate efficient mixing of the gaseous and/or solid carbon dioxide with the cement mix as the drum rotates. Any suitable positioning method and/or apparatus may be used to optimize the efficiency of uptake of carbon dioxide into the mixing cement as long as it positions the wand in a manner that provides efficient uptake of the carbon dioxide, for example, by positioning the wand so that the opening is directed to a point where a wave of concrete created by fins of a ready-mix drum folds over onto the mix; without being bound by theory it is thought that the wave folding over the fin immediately subsumes the carbon dioxide, e.g., solid carbon dioxide within the cement mix so that it releases gaseous carbon dioxide by sublimation into the mix rather than into the air, as it would do if on the surface of the mix. One exemplary positioning is shown in FIG. 5, where the wand is aimed at the second fin in the drum of the truck, on the bottom side of the fin. In a ready-mix truck carrying a full load, the opening of the wand may be very close to the surface of the mixing concrete, as described below, to facilitate the directional flow of the carbon dioxide mix into the proper area. Part or all of the wand may be made of flexible material so that if a fin or other part of the drum hits the wand it flexes then returns to its original position.
In certain embodiments, the invention provides a system for positioning a carbon dioxide delivery conduit on a ready-mix truck so that the opening of the conduit is directed to a certain position in the drum of the truck, for example, as described above. The conduit may deliver gaseous carbon dioxide or a mixture of gaseous and solid carbon dioxide through the opening. In the latter case, the conduit is constructed of materials that can withstand the liquid carbon dioxide carried by the conduit to the opening. The system can include a guide, which may be mounted on the truck, for example permanently mounted, that is configured to allow the reversible attachment and positioning of the conduit, for example, by providing a cylinder or holster into which the conduit can be inserted, so that the conduit is positioned at the desired angle for delivery of the carbon dioxide to a particular point, and a stop to ensure that the conduit is inserted so that the opening is at the desired distance from the concrete. This is merely exemplary and one of skill in the art will recognize that any number of reversible attachment and positioning devices may be used, so long as the angle and position of the opening relative to a desired point in the drum is obtained, e.g., clamps, etc. The wand is positioned in the guide, for example, manually by the driver of the ready-mix truck, or automatically by an automated system that senses the positions of the various components, or a combination thereof. When the wand is properly positioned, a signal is sent to a control system alerting the system that the wand is in position. The signal may be sent manually, e.g., by the driver of the truck after insertion of the wand, or by a batcher, or another operator, e.g., by pressing a button. Alternatively, a sensor may be tripped when the wand is positioned properly. Once the system controller is alerted that the wand is in position, carbon dioxide delivery can begin, either at that time or after a desired delay. The controller can be configured so that if the conduit is not positioned properly, e.g., the operator or sensor does not send the signal, the delivery will not start. The system may also be configured so that if one or more events occur during before, during, or after delivery, an alarm sounds and/or delivery is modulated, for example, stopped, or not initiated. For example, an alarm can sound if the wand loses signal from the positioning sensor during injection, or the pressure exceeds a certain threshold, e.g., the pressure is greater than 25 psi when both valves for delivery of gaseous and liquid carbon dioxide to the conduit is closed, e.g., when both are closed (which determines if a valve sticks open), or if the next truck in the queue has not been initiated in a certain amount of time. Exemplary logic for a controller can include:
If the wand loses signal during injection, an alarm light can come on and a message can pop on a HMI, for example, a screen, informing an operator that the injection wand is disconnected and to reconnect and press Start button to continue. There can also be an indicator, e.g., a button that indicates “Injection Complete” which would end that batch and record what was actually injected vs the target. In a batching facility in which a plurality of different trucks are being batched, a system controller may be configured to receive input regarding the identity of each truck at the carbon dioxide delivery site and select the appropriate action, e.g., delivery/no delivery, timing, flow, and amount of carbon dioxide delivered, and the like. For example, for entering a truck number that corresponds to the current truck being batched (signal being sent to plc), a dialog box can pop up when the system controller gets the signal from the customer PLC asking an operator to “Please input Identification Number” (e.g., a 1-10 digit number), alternatively, the truck identifier numbers can be in a predetermined order, e.g., sequential. To choose the option, there may be a selector switch on the maintenance screen. Feedback may also be provided to an operator, e.g., a batcher, showing relevant information for the batches run, such as Identification Number, Time Batched, Time Injected, Dose Required and Dose Injected, and the like. The units of the dose can be any suitable units, for example either lbs or kgs depending on the units selected. A “spreadsheet” can be provided that shows all batches from the current day (or makes the date selectable) so that the batcher can review it and scroll though, for example a printable spreadsheet.
Thus, for example, a carbon dioxide delivery system may be positioned at a ready-mix facility at a point where trucks stop for sufficient time for delivery of the desired dose of carbon dioxide to the drum of the truck, for example, at a wash rack. The carbon dioxide delivery system may be one that delivers a mixture of solid and gaseous carbon dioxide through an orifice, as described herein. The orifice may be operably connected to a conduit, such as a flexible conduit, that leads the carbon dioxide, e.g., a mixture of gaseous and solid carbon dioxide, to a wand that then delivers the carbon dioxide to the drum of the ready-mix truck. The flexible conduit is of sufficient length to allow for flow of carbon dioxide from the source of carbon dioxide to the wand when the wand is positioned at the desired position in the ready-mix truck, e.g., 5-30 feet in length, such as 10-25 feet in length, or any other suitable length according to the particular setup. The flexible conduit is generally constructed of insulating material, for example, a vacuum jacketed hose, that can withstand the temperatures of the mixture of gaseous and solid carbon dioxide. Any suitable diameter of hose may be used, for example, ¼-1 inch, or ¼-¾ inch, or about ½ inch diameter.
The flexible conduit can be operably connected to a wand, which, in general, is a rigid or semi-rigid conduit so that it can be reliably and reproducibly positioned to deliver the carbon dioxide to a desired location in a mixer, such as a drum of a ready-mix truck; in general the conduit will also include a handle that is insulated for ease of handling and for positioning the wand in a holder, e.g., a holster, on or near the drum of the ready-mix truck. The wand can be constructed of any suitable material or combination of materials, that is, e.g., material that can withstand the temperatures of the mixture of solid and gaseous carbon dioxide that pass through it. In certain embodiments, part or all of the wand comprises an inner aluminum tube and an outer rigid plastic tube; the aluminum tube may extend all of the way through the outer plastic tube or only part way. The outer pipe may be any suitable material, such as polyvinyl chloride (PVC) or acrylonitrile butadiene styrene (ABS). In certain embodiments, the aluminum tube extends only to the end of the handle, and the rest of the wand is plastic pipe. In certain embodiments, the wand is entirely constructed of the plastic pipe. These materials are merely exemplary and it will be appreciated that any material that imparts the necessary rigidity for directing the flow of carbon dioxide to the desired spot and the necessary robustness to withstand the temperatures and working conditions may be used. The length of the wand may be any suitable length that allows for ease of handling and for correct positioning; in certain embodiments the wand is 3-8 feet long, such as 3-7 feet long, or 3-6 feet long.
The wand preferably includes a handle or stop, which is of greater diameter than the rest of the wand and which is shaped to fit into a holder, e.g., a holster, that is attached to or near the drum of the ready-mix truck, e.g., at the hopper. The holder, e.g., holster, is attached to or near the drum of the ready-mix truck in such a position that the wand may be inserted into or attached to it, e.g., by the truck operator, and, once inserted, reliably and reproducibly directs carbon dioxide to the desired location in the drum of the truck. In general, the location is chosen to deliver carbon dioxide to a spot in a full truck that will cause the carbon dioxide to be subsumed into the mixing concrete in an efficient manner, as described herein. The handle or stop can be configured so as to lock the wand into place once inserted. As described elsewhere herein, the assembly may include a sensor, e.g., on the locking mechanism, to alert a controller system that the wand has been properly positioned; alternatively, an operator may manually alert the system that the wand is properly positioned, e.g., by pressing a button. The wand may also include, at the distal end, a flexible portion so that it can be contacted by the concrete truck fins or concrete without damage. In addition, the wand may be scored, e.g., at the point where the wand leaves the hopper and enters the truck so that if it gets caught and enough force is exerted upon it, it will break away without damaging the upper part of the wand. The wand may also have a hose breakaway in case the truck drives away without removing the wand. This breakaway can also sever a sensor wire, if included, telling the system that the wand is no longer locked in place and thus stopping flow if it has not already been stopped.
FIG. 6 shows one example of a wand and holder. Certain embodiments of the invention provide a positioning system for positioning a carbon dioxide delivery conduit in a drum of a ready-mix truck, wherein the positioning system is attached to the ready-mix truck, for example, at or near the drum of the ready-mix truck, and includes a holder into which the conduit can be positioned so that the opening of the conduit is in a desired location for delivery of carbon dioxide to the concrete of the ready-mix truck. The holder is attached to the truck, e.g., by welding or bolting or other suitable attachment method to provide a reliable attachment to the truck. The system may include a reversible locking mechanism for locking the conduit in place once it is inserted. The system thus may be, e.g., a holster as described herein, and include a reversible locking mechanism for locking the conduit in place once it is inserted. Thus, in an operation that includes a plurality of ready-mix trucks, for any truck for which carbon dioxide delivery is desired, a positioning system is affixed to the truck in a suitable location; each truck has its own positioning system that travels with the truck and is used, in combination with the wand and the carbon dioxide delivery and control system, when carbon dioxide delivery to a load of concrete is desired.
In embodiments in which carbon dioxide is contacted with the surface of the cement mix, e.g., hydraulic cement mix such as concrete, such as mixing concrete in a drum of a ready-mix truck, the flow of carbon dioxide may be directed from an opening or plurality of openings (e.g., conduit opening) that is at least 5, 10, 20, 30, 40, 50, 60, 70, 80, 90, or 100 cm from the surface of the cement mix, e.g., hydraulic cement mix during carbon dioxide flow, on average, given that the surface of the mix will move with mixing, and/or not more than 10, 20, 30, 40, 50, 60, 70, 80, 90, 100, 120, 140, 170, or 200 cm from the surface of the cement mix, e.g., hydraulic cement mix during carbon dioxide flow, on average. In certain embodiments, the opening is 5-100 cm from the surface, on average, such as 5-60 cm, for example 5-40 cm. In certain embodiments, the opening is 10-100 cm from the surface, on average, such as 10-60 cm, for example 10-40 cm. When the mixer is a drum of a ready-mix truck, these distances are generally calculated for a full load in the drum.
Thus, certain embodiments of the invention provide apparatus and methods for delivering carbon dioxide, e.g., a mixture of gaseous and solid carbon dioxide, to a concrete mix in a ready-mix truck at a distance of 5-100 cm from the surface, on average, such as 5-60 cm, for example 5-40 cm, or 10-100 cm from the surface, on average, such as 10-60 cm, for example 10-40 cm, from the surface of the mixing concrete. The dose of carbon dioxide delivered to the concrete may be any suitable dose, as described herein, The carbon dioxide may be delivered for any suitable length of time to reach the desired dose, for example, for 10-360 seconds, or 20-360 seconds, or 30-360 seconds, or 45-360 seconds, or 60-360 seconds, or 10-300 seconds, or 20-300 seconds, or 30-300 seconds, or 45-300 seconds, or 60-300 seconds, or 10-240 seconds, or 20-240 seconds, or 30-240 seconds, or 45-240 seconds, or 60-240 seconds.
In any of these systems, e.g., a delivery system that includes a rigid or semi-rigid wand that is inserted into a fixed holder attached on or near the drum of the ready-mix truck, flow of carbon dioxide may be measured and controlled as described herein; thus, the systems may include a flow sensing apparatus that determines the appropriate temperatures and pressures, and a controller that determines flow rate and time and determines total amount of carbon dioxide delivered to the drum of the truck, where the controller automatically stops the flow or signals to an operator who manually stops flow at the appropriate time, e.g., when a dose of carbon dioxide as described herein has been reached for the load of concrete in the truck.
Additional or alternative control systems and methods may be used. In certain embodiments, a control system or method includes feedback mechanisms where one or more characteristics of the concrete mix, and/or mixing apparatus and/or its environment is monitored by one or more sensors, which transmit the information to a controller which determines whether one or more parameters of the mix operation requires modulation and, if so, sends the appropriate output to one or more actuators to carry out the required modulation. The controller may learn from the conditions of one batch to adjust programming for subsequent batches of similar or the same mix characteristics to optimize efficiency and desired characteristics of the mix. Sensors may include one or more temperature sensors, carbon dioxide sensors, rheology sensors, weight sensors (e.g., for monitoring the exact weight of cement used in a particular batch), moisture sensors, other gas sensors such as oxygen sensors, pH sensors, and other sensors for monitoring one or more characteristics of a gas mixture in contact with the concrete mix, a component of the concrete mixing apparatus, a component exposed to the concrete mix, or some other aspect of the mix operation. Sensors also include sensors that monitor a component of the concrete mix apparatus, such as sensors that detect when mixing has begun, when components of a concrete mix have been added to a mixer, mass flow sensors, flow rate or pressure meter in the conduit, or other suitable sensors. Sensors, controllers, and actuators for control systems and methods and any such system and/or method may be used in embodiments of the present invention.
Certain embodiments of the invention provide one or more of an orifice as described, a conduit operably connected to the orifice to direct the carbon dioxide exiting the orifice, and, in some embodiments, a system for positioning the conduit so as to direct the carbon dioxide to a particular location, for example, a particular location in a drum of a ready-mix truck; the conduit apparatus may be affixed to the drum in a permanent or, preferably, temporary configuration. Certain embodiments of the invention provide for the positioning system itself, alone or affixed to a mixer, e.g., a ready-mix truck, or a plurality of positioning systems, each affixed to a separate mixer, e.g., to separate ready-mix trucks. Thus, for example, in a ready-mix operation, each truck that is designated as a potential receiver of carbon dioxide may have its own positioning system, e.g., a holster, affixed thereto in such a location as to position the conduit to deliver carbon dioxide to a desired location inside the drum of the truck while concrete is mixing in the drum, so that the conduit may be temporarily attached to different ready-mix trucks as desired to deliver carbon dioxide to the different trucks. Hence, in certain embodiments, the invention provides systems and methods for delivery of carbon dioxide to the drums of one or more ready-mix trucks where each truck to which carbon dioxide is to be delivered has affixed thereto a positioning system that travels with the truck, and a carbon dioxide delivery systems, for example as described herein, that includes a conduit for delivery of carbon dioxide from a source of carbon dioxide to the ready-mix truck, where each positioning system is affixed in a location and position such that the conduit may be temporarily attached to the truck and positioned in such a way as to allow carbon dioxide to be delivered to a desired location within the drum of the truck, for example, while concrete is mixing in the drum of the truck. Locations and positioning may be as described herein. The system may include at least 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 12, 15, 20, 25, 30, 40, or 50 separate ready-mix trucks, each with its own positioning system attached, and 1 or, in some cases, more than 1, such as 2, 3, 4, 5, or more than 5 carbon dioxide delivery systems that include a conduit that may be temporarily attached to the trucks for delivery of carbon dioxide from a source of carbon dioxide to the drum of the truck. The carbon dioxide delivery system may be positioned, when in use, at a location where the truck or trucks normally halt for a period sufficient to deliver a desired dose of carbon dioxide to the concrete in the truck, for example, at a location where the trucks normally halt for at least 1, 2, 3, 4, 5, 6, 7, 8, 9, or 10 minutes. For example, the delivery system may be positioned at a wash rack in a batching facility. In this way, carbon dioxide can be delivered to the trucks without significantly altering the time the trucks remain in the batching facility, as it is delivered during an operation that would normally take place, e.g., washing the trucks, and the only potential additional time would be in the attachment and detachment of the conduit, and in some cases the starting and stopping of delivery of the carbon dioxide, if done by the truck driver. Thus, the system and methods may allow delivery of a desired dose of carbon dioxide to the ready-mix trucks, such as a dose of 0.05-2% bwc, or any other dose as described herein, without prolonging the average time that a truck remains in the batching facility by more than 1, 2, 3, 4, 5, 6, 7, 8, 9, or 10 minutes, for example, by no more than 2 minutes, or no more than 4 minutes, or no more than 6 minutes, on average. The carbon dioxide delivery system may be a liquid delivery system and further include an orifice that allows liquid carbon dioxide, or a mixture of liquid and gaseous carbon dioxide, under pressure, to be converted to solid and gaseous carbon dioxide as it passes through the orifice to an area of lower pressure, for example, to an area of atmospheric pressure, as described herein. Systems and methods for monitoring the flow of carbon dioxide, such as those described herein, may be included in the systems and methods of delivering carbon dioxide to the drums of ready-mix trucks. Systems and methods for controlling the flow of carbon dioxide, such as those described herein, such as starting, stopping, and/or otherwise modulating the flow, may be included in the systems and methods of delivering carbon dioxide to the drums of ready-mix trucks.
In an alternative embodiment, each truck has an attached conduit, e.g., a hose or pipe onboard for carbon dioxide delivery to its drum. This can be, e.g., a line that mirrors the water input line on the truck from just above the water tank into the back of the truck. A flexible hose is connected to this line when carbonated concrete is required, for example, as indicated by a light that illuminates next to the hose in the batch house; the orifice and other parts of the apparatus are, e.g., proximal to the flexible hose. Once it is connected, a signal, such as from a sensor or a button press by the operator, indicates to the first controller that the hose is connected and the system can deliver carbon dioxide into the truck during the batching process. Once the delivery is complete, the line is disconnected and the operator can drive away. There can also be a safety to ensure the operator doesn't drive away with the line attached. The systems and methods lend themselves to retrofitting of existing operations, for example, retrofitting an existing ready-mix operation so as to allow delivery of solid and gaseous carbon dioxide to a desired location in separate ready-mix trucks.
Claim Rejections - 35 USC § 112(b)
The following is a quotation of 35 U.S.C. 112(b):
(b) CONCLUSION.—The specification shall conclude with one or more claims particularly pointing out and distinctly claiming the subject matter which the inventor or a joint inventor regards as the invention.
The following is a quotation of 35 U.S.C. 112 (pre-AIA ), second paragraph:
The specification shall conclude with one or more claims particularly pointing out and distinctly claiming the subject matter which the applicant regards as his invention.
Claim 46 is rejected under 35 U.S.C. 112(b) or 35 U.S.C. 112 (pre-AIA ), second paragraph, as being indefinite for failing to particularly point out and distinctly claim the subject matter which the inventor or a joint inventor (or for applications subject to pre-AIA 35 U.S.C. 112, the applicant), regards as the invention.
Claim 46 recites the limitation "the controller” in lines 1 and 4. There is insufficient antecedent basis for this limitation in the claim. Note claim 45 that recites “a control system” yet no claims refer to a controller.
Allowable Subject Matter
None.
Conclusion
The remarks filed 25 OCT 2025 are not persuasive.
With regard to the underlined language added to the preamble of claim 33, such language recites no structure whatsoever and is merely considered an intended use of the elements following the term “comprising”. "[A] statement of intended use.., does not qualify or distinguish the structural apparatus claimed over the reference." In re Sinex, 309 F.2d 488, 492 (CCPA 1962); In re Tuominen, 671 F.2d 1359, 1361 (CCPA 1982) ("The only distinction to which Tuominen can aver is a difference in use, which cannot render the claimed composition novel."); In re Yanush, 477 F.2d 958, 959 (CCPA 1973) ("Appellant's use limitation does not impart a structural feature different from those of the prior art."); In re Casey, 370 F.2d 576, 580 (CCPA 1967) ("The claims in issue call for an apparatus or machine, viz. a tape dispensing machine. The manner or method in which such machine is to be utilized is not germane to the issue of patentability of the machine itself."); In re Hack, 245 F.2d 246, 248 (CCPA 1957) ("These cases are merely expressive of the principle that the grant of a patent on a composition or machine cannot be predicated on a new use of that machine or composition.").
Moreover, as held in In re Casey, 370 F.2d 576, 152 USPQ 235 (CCPA 1967), "the manner or method in which such machine [the source and conduits of claim 33] is to be utilized is not germane to the issue of patentability of the machine itself." See MPEP 2115.
There is no evidence of record that conduits outside of the claimed ranges of length and inside diameter would result in failure of the apparatus to adequately deliver carbon dioxide to a destination. Accordingly, the examiner argues that that the claimed conduit lengths and inside diameters are well within the capabilities of one skilled in the art and such conduit lengths and inside diameters are far from being inventive since they could be determined by routine experimentation and in view of the four corners of the WILLIAMSON and readily applicable to the WILLIAMSON device.
Applicant has utterly failed to adequately rebut the examiner’s conclusion of obviousness of the conduit lengths and inside diameters since
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Applicant has not provided a showing relating to the criticality of the change. "The law is replete with cases in which the difference between the claimed invention and the prior art is some range or other variable within the claims. . . . In such a situation, the applicant must show that the particular range is critical, generally by showing that the claimed range achieves unexpected results relative to the prior art range." In re Woodruff, 919 F.2d 1575, 16 USPQ2d 1934 (Fed. Cir. 1990). See also Minerals Separation, Ltd., et al. v. Hyde, 242 U.S. 261, 271 (1916) (a patent based on a change in the proportions of a prior product or process (changing from 4-10% oil to 1% oil) must be confined to the proportions that were shown to be critical (1%)); In re Scherl, 156 F.2d 72, 74-75 (CCPA 1946) ("Where the issue of criticality is involved, the applicant has the burden of establishing his position by a proper showing of the facts upon which he relies."); In re Becket, 88 F.2d 684 (CCPA 1937) ("Where the component elements of alloys are the same, and where they approach so closely the same range of quantities as is here the case, it seems that there ought to be some noticeable difference in the qualities of the respective alloys."); In re Lilienfeld, 67 F.2d 920, 924 (CCPA 1933) ("It is well established that, while a change in the proportions of a combination shown to be old, such as is here involved, may be inventive, such changes must be critical as compared with the proportions used in the prior processes, producing a difference in kind rather than degree."); In re Wells, 56 F.2d 674, 675 (CCPA 1932) ("Changes in proportions of agents used in combinations . . . in order to be patentable, must be critical as compared with the proportions of the prior processes."). (emphasis added).
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Applicant also argues that the recited conduit parameters (lengths and inside diameters) are not shown in the prior art, however, the recited lengths and inside diameters are obvious to one skilled in the art as noted in the rejection and Applicant fails to provide compelling evidence that the length is critical and therefore nonobvious (see MPEP 716.02 - 716.02(g)). Applicant’s own specification supports the non-critical nature of these parameters as noted in the rejection above. Again, “[W]here the general conditions of a claim are disclosed in the prior art, it is not inventive to discover the optimum or workable ranges by routine experimentation.” In re Aller, supra.
To establish unexpected results over a claimed range, applicants should compare a sufficient number of tests both inside and outside the claimed range to show the criticality of the claimed range. In re Hill, 284 F.2d 955, 128 USPQ 197 (CCPA 1960). The examiner notes the current record is devoid of any test results or discussions of results inside and outside the claimed ranges of the disclosed or claimed parameters. The alleged criticality asserted by Applicant in the remarks thus fails in this regard as well.
Any differences between the claimed invention and the prior art may be expected to result in some differences in properties. The issue is whether the properties differ to such an extent that the difference is really unexpected. In re Merck & Co., 800 F.2d 1091, 231 USPQ 375 (Fed. Cir. 1986) (differences in sedative and anticholinergic effects between prior art and claimed antidepressants were not unexpected). In In re Waymouth, 499 F.2d 1273, 1276, 182 USPQ 290, 293 (CCPA 1974), the court held that unexpected results for a claimed range as compared with the range disclosed in the prior art had been shown by a demonstration of "a marked improvement, over the results achieved under other ratios, as to be classified as a difference in kind, rather than one of degree." Compare In re Wagner, 371 F.2d 877, 884, 152 USPQ 552, 560 (CCPA 1967) (differences in properties cannot be disregarded on the ground they are differences in degree rather than in kind); Ex parte Gelles, 22 USPQ2d 1318, 1319 (Bd. Pat. App. & Inter. 1992) ("we generally consider a discussion of results in terms of ‘differences in degree’ as compared to ‘differences in kind’ . . . to have very little meaning in a relevant legal sense"). See also UCB, Inc. v. Actavis Labs, UT, Inc., 65 F.4th 679, 693, 2023 USPQ2d 448 (Fed. Cir. 2023) ("A difference of degree is not as persuasive as a difference in kind – i.e., if the range produces ‘"a new property dissimilar to the known property,’" rather than producing a predictable result but to an unexpected extent.").
The evidence relied upon should establish "that the differences in results are in fact unexpected and unobvious and of both statistical and practical significance." Ex parte Gelles, 22 USPQ2d 1318, 1319 (Bd. Pat. App. & Inter. 1992) - such is not established in this application.
Arguments presented by the applicant cannot take the place of evidence in the record and evidence is lacking in this instance. In re Schulze, 346 F.2d 600, 602, 145 USPQ 716, 718 (CCPA 1965) and In re De Blauwe, 736 F.2d 699, 705, 222 USPQ 191, 196 (Fed. Cir. 1984). Examples of statements which are not evidence and which must be supported by an appropriate affidavit or declaration include statements regarding unexpected results, commercial success, solution of a long-felt need, inoperability of the prior art, invention before the date of the reference, and allegations that the author(s) of the prior art derived the disclosed subject matter from the inventor or at least one joint inventor.
Applicants must further show that the unexpected results were greater than those which would have been expected from the prior art to an unobvious extent, and that the results are of a significant, practical advantage [such a showing has not been established in the record of this application]. Ex parte The NutraSweet Co., 19 USPQ2d 1586 (Bd. Pat. App. & Inter. 1991).
Whether the unexpected results are the result of unexpectedly improved results or a property not taught by the prior art, the "objective evidence of nonobviousness must be commensurate in scope with the claims which the evidence is offered to support." In other words, the showing of unexpected results must be reviewed to see if the results occur over the entire claimed range. In re Clemens, 622 F.2d 1029, 1036, 206 USPQ 289, 296 (CCPA 1980) (Claims were directed to a process for removing corrosion at "elevated temperatures" using a certain ion exchange resin (with the exception of claim 8 which recited a temperature in excess of 100°C). Appellant demonstrated unexpected results via comparative tests with the prior art ion exchange resin at 110°C and 130°C. The court affirmed the rejection of claims 1-7 and 9-10 because the term "elevated temperatures" encompassed temperatures as low as 60°C where the prior art ion exchange resin was known to perform well. The rejection of claim 8, directed to a temperature in excess of 100°C, was reversed.). See also In re Peterson, 315 F.3d 1325, 1329-31, 65 USPQ2d 1379, 1382-85 (Fed. Cir. 2003) (data showing improved alloy strength with the addition of 2% rhenium did not evidence unexpected results for the entire claimed range of about 1-3% rhenium); In re Grasselli, 713 F.2d 731, 741, 218 USPQ 769, 777 (Fed. Cir. 1983) (Claims were directed to certain catalysts containing an alkali metal. Evidence presented to rebut an obviousness rejection compared catalysts containing sodium with the prior art. The court held this evidence insufficient to rebut the prima facie case because experiments limited to sodium were not commensurate in scope with the claims.). In this instance, Applicant has not provided a showing of unexpected results that can be reviewed to see if the results occur over the entire broadly claimed range.
Applicant argues that as stated in the specification, "The methods and compositions of the present invention provide reproducible dosing of solid and gaseous carbon dioxide, under intermittent conditions and at low doses and short delivery times, without using apparatus and methods that lead to significant loss of carbon dioxide in the process." ( [0013]) and "Methods and systems provided herein can allow accurate, precise and reproducible dosing of low doses of carbon dioxide, e.g. as described above, with liquid carbon dioxide being converted to a mixture of solid and gaseous carbon dioxide, without venting of gaseous carbon dioxide in the line that carries the liquid carbon dioxide.” - remarks on page 13. It is unclear how reproducible dosing of solid and gaseous carbon dioxide, under intermittent conditions and at low doses and short delivery times, without venting and without leading to significant loss of carbon dioxide in the process presents any structure to define over the prior art or establishes criticality of the conduit parameters.
Applicant further states “the characteristics of the first conduit must be such that the amount of gas in the first conduit is minimized, so that a suitably high proportion of solid carbon dioxide is produced at the orifice, and so that reproducibility can be achieved between runs, without the necessity to vent gaseous carbon dioxide from the first conduit or reliquefy gaseous carbon dioxide produced” and then concludes “[t]hus, the length and diameter of the first conduit recited in claim 33 are not arbitrary, they are critical to achieving both a reproducible dose between runs, sufficient solid carbon dioxide, and to eliminate the necessity for venting or reliquification.” Likewise, it is unclear how reproducible dosing of solid and gaseous carbon dioxide, under intermittent conditions and at low doses and short delivery times, without venting or reliquification and without leading to significant loss of carbon dioxide in the process presents any structure to define over the prior art or establishes criticality of the conduit parameters. As noted previously, the record lacks a sufficient number of tests both inside and outside the claimed ranged to show the criticality of the claimed ranges related to the conduits.
Applicant further argues “the characteristics of the second conduit, which carries the mixture of solid and gaseous carbon dioxide to the destination, must be such that a proportion of solid carbon dioxide of at least 35% is maintained as it travels to the destination over a length of at least 30 feet” and “[t]hus, the smooth bore, insulation, and relatively small diameter of the second conduit are, again, critical, in this case for maintaining a proportion of solid carbon dioxide of at least 35% at the destination when the length of the second conduit is at least 30 feet.”
WILLIAMSON shows the second conduit 40 having a smooth bore (i.e., no irregularities on the inside surface of the conduit occur and that there are no convolutions of the conduit as defined by Applicant) and EP ‘771 teaches the insulated conduit for delivering carbon dioxide to a destination. The concept of providing a second conduit having a selected inside diameter to maximize flow rate is determined by fluid dynamics, well within the capabilities of one skilled in the art.
The instant specification states that the “second conduit may be, e.g., at least 5, 10, 15, 20, 25, 30, 35, 40, 45, 50, 55, 60, 65, 70, 80, 90, or 100 feet long, in order to reach the final point where carbon dioxide will be used; length of the second conduit will in general depend on the particular operational setup in which carbon dioxide is being used. Because the first conduit typically is kept as short as possible, and the second conduit must be a length suitable to reach to point of use, which is often far from the injector orifice. . .”. Thus, the length of the second conduit is not as a result of some aspect of criticality but rather determined by operational or environmental needs, that is the distance needed to span the distance between the first conduit and the point of use, easily determined by one skilled in the art.
In instant [0031] it is disclosed that the “second conduit is configured to deliver the mixture of solid and gaseous carbon dioxide to its place of use with very little conversion of solid to gaseous carbon dioxide, so that the mixture of solid and gaseous carbon dioxide delivered at the point of use is still at a high ratio of solid to gas, for example, the proportion of solid carbon dioxide in the mixture can be at least 35, 36, 37, 38, 39, 40, 41, 42, 43, 44, 45, 46, 47, 48, or 49% of the total.” These percentages are not associated with any particular lengths or inside diameters of the second conduit. Therefore, Applicant’s conclusion that the relatively small diameter of the second conduit is critical for maintaining a proportion of solid carbon dioxide of at least 35% at the destination when the length of the second conduit is at least 30 feet is not commensurate with the disclosure of the instant specification.
In view of the foregoing, when all of the evidence and remarks are considered, the totality of the rebuttal evidence of nonobviousness fails to outweigh the evidence of obviousness.
Accordingly. . .
THIS ACTION IS MADE FINAL. Applicant is reminded of the extension of time policy as set forth in 37 CFR 1.136(a).
A shortened statutory period for reply to this final action is set to expire THREE MONTHS from the mailing date of this action. In the event a first reply is filed within TWO MONTHS of the mailing date of this final action and the advisory action is not mailed until after the end of the THREE-MONTH shortened statutory period, then the shortened statutory period will expire on the date the advisory action is mailed, and any nonprovisional extension fee (37 CFR 1.17(a)) pursuant to 37 CFR 1.136(a) will be calculated from the mailing date of the advisory action. In no event, however, will the statutory period for reply expire later than SIX MONTHS from the mailing date of this final action.
Any inquiry concerning this communication or earlier communications from the examiner should be directed to CHARLES COOLEY whose telephone number is (571)272-1139. The examiner can normally be reached M-F 9:30 AM - 6:00 PM.
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If attempts to reach the examiner by telephone are unsuccessful, the examiner’s supervisor, CLAIRE X. WANG can be reached at 571-272-1700. The fax phone number for the organization where this application or proceeding is assigned is 571-273-8300.
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/CHARLES COOLEY/Examiner, Art Unit 1774
25 FEB 2026