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 .
Priority
Acknowledgment is made of a claim for foreign priority under 35 U.S.C. § 119(a)-(d). All of the CERTIFIED copies of the priority documents have been received in this national stage application from the International Bureau (PCT Rule 17.2(a)).
Information Disclosure Statement
Note the attached PTO-1449 forms submitted with the Information Disclosure Statements.
Specification
The specification has not been checked to the extent necessary to determine the presence of all possible minor errors. Applicant's cooperation is requested in correcting any errors of which applicant may become aware in the specification.
The Abstract of the Disclosure is objected to because:
a. it lacks substance as it is not an adequate and clear statement of the contents of the disclosure. A reading of the abstract does not provide the character of the subject matter covered by the disclosure. The abstract should be more comprehensive of the disclosed subject matter by mentioning the liquid and gaseous sealing mediums.
Correction is required. See MPEP § 608.01(b).
The title of the invention is not descriptive. A new title is required that is clearly indicative of the invention to which the claims are directed (MPEP 606.01).
Claim Rejections - 35 U.S.C. § 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.
The inquiry during examination is patentability of the invention as the inventor or a joint inventor regards such invention. If the claims do not particularly point out and distinctly claim that which the inventor or a joint inventor regards as his or her invention, the appropriate action by the examiner is to reject the claims under 35 U.S.C. 112(b) or pre-AIA 35 U.S.C. 112, second paragraph. In re Zletz, 893 F.2d 319, 13 USPQ2d 1320 (Fed. Cir. 1989).
Claims 21-32 are rejected under 35 U.S.C. 112(b) as being indefinite for failing to particularly point out and distinctly claim the subject matter which the inventor or a joint inventor, or for pre-AIA the applicant regards as the invention.
NOTE: Per 37 CFR 1.75(c), dependent claims shall be construed to include all the limitations of the claim incorporated by reference into the dependent claim. Accordingly, by definition, any claims that depend from a claim that is deemed indefinite under 35 USC 112(b) will also be considered indefinite and identified in the list of rejected claims above, even if such claims are themselves free of indefiniteness under § 112(b).
Claim 21, lines 17-19 appear to duplicate the subject matter recited in lines 15-16 - the distinction between these two sets of lines is unknown.
Claim 25, line 2 repeats “sealing chambers”.
Claim 27, line 4: “the annual wall” lacks antecedent basis.
Claims 28 and 29: “the intermediate wall” lacks antecedent basis.
The use of a confusing variety of terms for the same thing should not be permitted - MPEP 608.01(o). For example, “annular intermediate wall” vs. “intermediate wall” - refers to the same wall?
Also see 37 CFR 1.121(e) Disclosure consistency. The disclosure must be amended, when required by the Office, to correct inaccuracies of description and definition, and to secure substantial correspondence between the claims, the remainder of the specification, and the drawings.
Claim Rejections - 35 USC § 102
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 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). "A claim is anticipated only if each and every element as set forth in the claim is found, either expressly or inherently described, in a single prior art reference." Verdegaal Bros. Inc. v. Union Oil Co. of California, 814 F.2d 628, 631 (Fed. Cir. 1987).
The express, implicit, and inherent disclosures of a prior art reference may be relied upon in the rejection of claims under 35 U.S.C. 102 or 103. "The inherent teaching of a prior art reference, a question of fact, arises both in the context of anticipation and obviousness." In re Napier, 55 F.3d 610, 613, 34 USPQ2d 1782, 1784 (Fed. Cir. 1995) (affirmed a 35 U.S.C. 103 rejection based in part on inherent disclosure in one of the references). See also In re Grasselli, 713 F.2d 731, 739, 218 USPQ 769, 775 (Fed. Cir. 1983). See MPEP 2112.
The following is a quotation of the appropriate paragraphs of 35 U.S.C. 102 that form the basis for the rejections under this section made in this Office action:
A person shall be entitled to a patent unless—
(a)(1) the claimed invention was patented, described in a printed publication, or in public use, on sale or otherwise available to the public before the effective filing date of the claimed invention.
Claims 21, 22, 23, 24, 25, 26, 27, 28, 29, 31, 33, 34, and 35 are rejected under 35 U.S.C. 102(a)(1) as being anticipated by GB 616405 that discloses a method centrifuge (particularly in Figure 4) configured to separate or clarify a flowable product or a flowable suspension into at least two phases in a centrifugal field in continuous operation, wherein the centrifuge comprises a rotatably mounted drum 7 drivable by a drive motor (proximate 2 in Figure 1) to rotate about a vertical axis of rotation; and a drum shell made of metal per MPEP 608.02:
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wherein the rotatably mounted drum 7 comprises a feed pipe 18 and as seen in the embodiment of Figure 4 at least one gripper chamber 13 with a gripper 43 configured to discharge separated or clarified liquid; and at least two axially superimposed sealing chambers (first and second chambers 60 and 61) arranged above the gripper chamber 13; wherein each of the at least two axially superimposed sealing chambers has a sealing disk 46 and 59 projecting into the respective one of the at least two axially superimposed sealing chambers 60 and 61; wherein the rotatably mounted drum 7 further comprises at least one feed channel 64 configured to feed a sealing medium into one of the at least two axially superimposed sealing chambers 60, 61 or at least one feed channel 64 configured to feed the sealing medium into the respective one of the at least two axially superimposed sealing chambers sealing chambers 60 and 61;
a line 65 and/or 67 capable of feeding or evacuating a gas configured to feed a gas into an annular space around an annular intermediate wall 62 extending radially inwards from the drum shell between the at least two axially superimposed two sealing chambers 60 or 61, or by evacuating a gas from the annular space during operation of the centrifuge ;
an outlet proximate 38 configured to discharge a gas from the annular space;
wherein the at least two axially superimposed sealing chambers comprise a first sealing chamber 60 or 61 delimited radially downwards from the gripper chamber 13 by an annular wall (above 43) extending radially inwards from the drum shell in a region of the drum head 41 and perpendicularly to the axis of rotation and ends radially spaced from an inner shaft arrangement 14, which does not rotate with the rotatably mounted drum 7 during operation but extends axially into the rotatably mounted drum 7;
wherein the at least two axially superimposed sealing chambers comprise a first sealing chamber 60; and a second sealing chamber 61, wherein the second sealing chamber 61 is arranged above the first sealing chamber 60, wherein the first sealing chamber 60 is axially delimited by the annular intermediate wall 62 from the second sealing chamber, which extends radially inwards from the drum shell in the region of the drum head 41 perpendicular to the axis of rotation and ends radially spaced from an inner shaft arrangement 14, which does not rotate with the rotatably mounted drum during operation but extends axially into the rotatably mounted drum 7;
wherein the at least two axially superimposed sealing chambers 60 and 61 sealing chambers further comprise a second sealing chamber 61 having an annular wall 63 and a radially inner overflow edge arranged at and delimiting a top of the annular wall, wherein the radially inner overflow edge extends radially and perpendicularly to the axis of rotation inwards from the drum shell in the region of the drum head and ends radially spaced from an inner shaft arrangement 14, which does not rotate with the drum during operation but extends axially into the drum 7;
and depending upon where the unspecified “a mouth” is construed, a mouth (or portion) of the feed channel 64 can be deemed disposed at a smaller or at a greater radius than a radius of a radial inner edge of the intermediate wall 62;
wherein the sealing medium flows from an inherent reservoir (or source) located outside the centrifuge into the at least one feed channel 64.
The methods being disclosed at page 4, line 92 - page 5, line 62.
With regard to the apparatus claims which recite the work (such as the gas of claim 22 or the sealing gas of claim 24), note that “[e]xpressions relating the apparatus to contents thereof during an intended operation are of no significance in determining patentability of the apparatus claim.” Ex parte Thibault, 164 USPQ 666, 667 (Bd. App. 1969). Furthermore, “[i]nclusion of material or article worked upon by a structure being claimed does not impart patentability to the claims.” In re Young, 75 F.2d 966, 25 USPQ 69 (CCPA 1935) (as restated in In re Otto, 312 F.2d 937, 136 USPQ 458, 459 (CCPA 1963)).
Accordingly, the recited gas of claim 22 and sealing gas of claim 24 are merely the contents of the apparatus during an intended operation and are thus of no patentable significance in these pending apparatus claims. The recited structure of apparatus claim 22, namely “a line” capable of feeding a substance or discharging a substance from the centrifuge, is met by the “line” 64 of GB ‘405, irrespective of what substance and in what direction said substance flows.
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.
When considering the prior art in its entirety, note Allied Erecting v. Genesis Attachments, 825 F.3d 1373, 1381, 119 USPQ2d 1132, 1138 (Fed. Cir. 2016) ("Although modification of the movable blades may impede the quick change functionality disclosed by Caterpillar, ‘[a] given course of action often has simultaneous advantages and disadvantages, and this does not necessarily obviate motivation to combine.’" (quoting Medichem, S.A. v. Rolabo, S.L., 437 F.3d 1157, 1165, 77 USPQ2d 1865, 1870 (Fed Cir. 2006) (citation omitted))). However, "the prior art’s mere disclosure of more than one alternative does not constitute a teaching away from any of these alternatives because such disclosure does not criticize, discredit, or otherwise discourage the solution claimed…." In re Fulton, 391 F.3d 1195, 1201, 73 USPQ2d 1141, 1146 (Fed. Cir. 2004).
In view of the 103 guidance above, claims 30-32 and 35 are rejected under 35 U.S.C. 103 as being unpatentable over GB 616405 in view of BORGSTROM et al. (US 2008/0171645 A1).
GB 616405 does not disclose pressurizing a space within the centrifuge via a sealing gas sourced from a reservoir or the gas sensor. BORGSTROM et al. discloses an analogous drum type centrifuge that is designed for separation of a product in a relatively heavy phase and relatively light phase. Furthermore, the centrifugal separator may be designed for separation of sludge or a solid phase in form of heavy particles. The centrifugal separator comprises a centrifuge rotor 1, which is mounted to a spindle 2. The spindle 2 is journelled in a bearing 3 and driven by means of a suitable drive member 4, which is provided in a frame 5. The rotor 1 is provided in a casing 6 and is by means of the drive member 4 rotatable around an axis x of rotation. The rotor 1 comprises a rotor wall 7, which encloses a separation space 8, see FIGS. 2-5. The separation space 8 has a radially outer part 11 in which the separated heavy phase is collected during operation, and a radially inner part 12, in which the separated light phase is collected during operation. Furthermore, the separation space 8 has a central gas-filled space 13 against which the collected separated light phase forms a free liquid surface. The radially outer part 11, i.e. the part for the separated heavy phase, is separated from the radially inner part 12, i.e. the part for the separated light phase, by an interface layer level 14 formed during operation. The centrifuge rotor 1 also comprises in a manner known per se a set of conical separation discs 15, which are disclosed schematically in FIGS. 2-5. The separation discs 15 are provided between an upper delimiting disc 16 and a lower delimiting disc 17 which comprises an inlet 18 for the product to be separated. Moreover, centrifugal separator comprises an inlet 21, a first outlet 22 and a second outlet 23. The inlet 21 comprises a stationary inlet conduit 24 which extends into the separation space 8 through the rotor wall 7. The inlet 21 is arranged to permit during operation feeding of the product to the separation space 8.
The first outlet 22 extends from the radially outer part 11 through the rotor wall 7 and is arranged to permit during operation discharge of the heavy phase through the first outlet 22. The first outlet 22 comprises a stationary first outlet conduit 25 and a stationary paring disc 26, which is connected to the first outlet conduit 25 and which is provided in a first paring chamber 27 for the heavy phase. The first paring chamber 27 communicates with the radially outer part 11 via one or several heavy phase channels 28. The second outlet 23 extends from the radially inner part 12 through the rotor wall 7 and is arranged to permit during operation discharge of the light phase through the second outlet 23. The second outlet 23 comprises a stationary second outlet conduit 30 and a stationary paring disc 31, which is connected to the second outlet conduit 30 and which is provided in a second paring chamber 32 for the light phase. The second paring chamber 32 communicates with the radially inner part 12 via an overflow outlet 38 provided therebetween. The centrifugal separator is designed in such a way that the separation space 8 is closed to an environment and permits maintaining of a gas pressure in the central gas-filled space 13 of the separation space 8, which gas pressure deviates from the pressure of the environment. This closing of the separation space 8 may be provided in different ways, which is illustrated in the various embodiments in FIGS. 2-5.
In the first embodiment, which is disclosed in FIG. 2, and the third embodiment, which is disclosed in FIG. 4, the casing 6 is open to the environment, wherein the separation space 8 is closed by means of the first paring chamber 27 and the first paring disc 26, which forms a liquid seal preventing the gas pressure in the gas-filled space 13 of the separation space 8 from propagating out to the environment. In the first and third embodiments, the second paring disc 31 may possibly but not necessarily be provided with a venting hole 35 which permits that the pressure propagates through the second paring chamber 32. Such a venting hole 35 is illustrated in FIG. 4.
In the third embodiment, which is disclosed in FIG. 4, an overflow outlet 39 is provided between the radially outer part 11 and the first outlet 22, or more specifically between the radially outer part 11 and the first paring chamber 27.
In the second embodiment, which is disclosed in FIG. 3, and the fourth embodiment, which is disclosed in FIG. 5, the separation space 8 is closed by means of the casing 6, which completely encloses the centrifuge rotor 1 relatively the environment and forms a pressure vessel. In the second embodiment and the fourth embodiment, both the second paring disc 31 and the first paring disc 26 may possibly but not necessarily be provided with a venting hole 35, which permits that the pressure propagates through the two paring chambers 27 and 32. An overflow outlet 38 is provided between the radially inner part 12 and the second outlet 23, or more specifically between the radially inner part 12 and the second paring chamber 32.
In the fourth embodiment, which is disclosed in FIG. 5, an overflow outlet 39 is provided between the radially outer part 11 and the first outlet 22, or more specifically between the radially outer part 11 and the first paring chamber 27.
The centrifugal separator also comprises control equipment arranged to permit during operation control of the interface layer level 14 to a desired radial position by controlling the counter pressure in at least one of the first outlet 22 and the second outlet 23. The control equipment comprises a control unit 50. A sensor is connected to the control unit 50 and provided to sense during operation a parameter related to the gas pressure in the gas-filled space of the separation space 8. In the embodiments disclosed, the sensor is a pressure sensor 51, which senses a gas pressure which is substantially equal to the gas pressure in the central gas-filled space 13 of the separation space 8. In the first and third embodiments, the pressure sensor 51 is provided in the central gas-filled space 13 and in the second and fourth embodiments, the pressure sensor 51 is provided outside the rotor 1 but inside the closed casing 6.
Instead of sensing directly the gas pressure in the central gas-filled space 13 of the separation space 8, the sensor may sense another pressure related to this gas pressure, or any other parameter related to this pressure.
The control equipment is arranged to control the counter pressure in at least one of the first outlet 22 and the second outlet 23 depending on the pressure sensed by the pressure sensor 51 for controlling the interface layer level 14 to the desired radial position.
In the first embodiment, which is disclosed in FIG. 2, the control equipment is arranged to control the counter pressure in the first outlet 22. Thanks to the overflow outlet 38, between the radially inner part 12 and the second outlet 23, the radial position of the interface layer level 14 may be determined by the counter pressure in the first outlet 22. This counter pressure can be controlled in various ways. According to one variant, the counter pressure may be controlled by an influence or a throttling of a flow of the heavy phase discharged through the first outlet 22. Such a throttling may be provided in an easy manner by means of a valve 55. The valve 55 is suitably connected to the control unit 50, which controls the valve 55 in response to the gas pressure sensed by the pressure sensor 51. If the gas pressure in the central gas space 13 of the separation space 8 increases, the counter pressure in the first outlet 22 may rapidly be increased so that the desired radial position of the interface layer level 14 is maintained. According to another variant, the control equipment may be arranged to control also the counter pressure in the first outlet 22 by when needed permit providing of a flow into the centrifuge rotor 1 through the first outlet 22. Such a flow of heavy phase back into the radially outer part 11 may be provided by means of a control fluid, which is supplied from any suitable source 56 via a conduit 57 which is connected to the first outlet conduit 25. The source 56 provides the control fluid at a sufficient pressure and the counter pressure may in this case be controlled by means of a valve 58 on the conduit 57. Also the valve 58 is connected to the control unit 50, which controls the valve 58 in response to the gas pressure sensed by the pressure sensor 51.
If for instance a too large quantity of sludge, solid particles and and/or heavy phase has been discharged via the nozzles 34 the interface layer level and thus also the free liquid surface in the first paring chamber 27 will be displaced radially outwardly, wherein the liquid covering of the first paring disc 26 decreases, which leads to a reduction of the pressure in the first outlet 22. This can be counteracted by throttling the flow by means of the valve 55 or by supplying heavy phase via the conduit 57. The control fluid may be formed by the discharged heavy phase which is fed back into the radially outer part 11 or by a separate fluid, which is fed into the radially outer part 11 via the conduit 57 and the first outlet conduit 25 and which has a density corresponding to the density of the heavy phase.
The second embodiment, which is disclosed in FIG. 3, differs from the first embodiment in that the separation space is closed by means of the casing 6 as has been described above. It is to be noted that in the second embodiment both the paring discs 26 and 31 may be provided with venting holes 35, which enable the pressure sensor 51 in the second embodiment to be provided outside the rotor 1 but inside the casing 6 instead of inside the rotor 1. To the rest, the control equipment is substantially identical to the control equipment of the first embodiment. Since the counter pressure control also in the second embodiment takes place on the heavy phase, an overflow outlet 38 is advantageously provided between the radially inner part 12 and the second outlet 23.
The third embodiment, which is disclosed in FIG. 4, differs from the first embodiment in that the control equipment is arranged to control the counter pressure in the second outlet 23. Thanks to the overflow outlet 39 between the radially outer part 11 and the first outlet 22, the radial position of the interface layer level 14 may be determined by the counter pressure in the second outlet 23. This counter pressure may be controlled in substantially the same way as in the first embodiment. According to a variant, the counter pressure may be controlled by a influence or a throttling of a flow of the light phase discharged through the second outlet 23. Such a throttling may be provided in an easy manner by means of a valve 65. The valve 65 is suitably connected to the control unit 50, which controls the valve 65 in response to the gas pressure sensed by the pressure sensor 51. If the gas pressure in the central gas space 13 of the separation space 8 increases, the counter pressure in the second outlet 23 may rapidly be increased so that the desired radial position of the interface layer level 14 is maintained. As mentioned above, it is also possible within the scope of the invention that the control equipment is arranged also to control the counter pressure in the second outlet 23 by when needed permitting providing of a flow into the centrifuge rotor 1 through the second outlet 23. Such a flow of light phase back into the radially outer part 11 may be provided by means of a control fluid supplied from any suitable source 66 via a conduit 67 which is connected to the second outlet conduit 30. The source 66 supplies the control fluid at a sufficient pressure and the counter pressure may in this case be controlled by means of a valve 68 on the conduit 67. Also the valve 68 is connected to the control unit 50, which controls the valve 68 in response to the gas pressure sensed by the pressure sensor 51.
If the interface layer level 14 is displaced for instance radially inwardly, the free liquid surface in the radially inner part 12 is displaced radially outwardly, wherein the liquid covering of the second paring disc 38 decreases, which leads to a reduction of the pressure in the second outlet 23. This may be counteracted by throttling the flow through the valve 65, but it is also possible in this embodiment to counteract this by supplying the light phase to the radially inner part 12 via the conduit 67 and the second outlet conduit 30. The control fluid may be formed by the discharged light phase which is fed back into the radially inner part 12 or by a separate fluid, which is fed into the radially inner part 12 via the conduit 67 and the second outlet 30 and which has a density corresponding to the density of the light phase.
The fourth embodiment, which is disclosed in FIG. 5, differs from the third embodiment in that the separation space 8 is closed by means of the casing 6 as has been described above. It is to be noted that in the fourth embodiment, both the paring discs 26 and 31 may be provided with venting holes 35, which enable the pressure sensor 51 in the fourth embodiment to be provided outside the rotor 1 but inside the casing 6 instead of inside the rotor 1. To the rest, the control equipment is substantially identical to the control equipment of the third embodiment. Since the counter pressure control also in the fourth embodiment takes place on the light phase, an overflow outlet 39 is advantageously provided between the radially outer part 11 and the first outlet 22.
Thus, BORGSTROM et al. (US 2008/0171645 A1) discloses an analogous drum type centrifuge with a gas sensor 51 and wherein a sealing gas flows from a gas reservoir 56 via a line 22, 25 into an annular space portion 27 of the centrifuge under supervision of a control unit and the gas can be discharged from any discharge line of the centrifuge.
It would have been obvious to one skilled in the art before the effective filing date of the invention to have provided the centrifuge of GB ‘405 with a gas sensor and a gas reservoir for supplying a sealing gas to to a space within the centrifuge drum as disclosed by BORGSTROM et al. to enable the injection of a gas fed into the centrifuge from a gas reservoir to provide a cushion of gas within portions of the centrifuge to exclude penetration of oxygen to thereby avoid undesirable oxidation processes of the substances within the centrifuge and/or to close the separation space to an environment and permits maintaining of a gas pressure in the central gas-filled space of the separation space, which gas pressure deviates from the pressure of the environment wherein the centrifugal separator comprises a sensor, which is provided to sense, during operation, a parameter that is related to the gas pressure in the central gas-filled space of the separation space and which is connected to the control equipment wherein the control equipment is arranged to control the counter pressure in at least one of the first outlet and the second outlet in response to the sensed parameter for controlling the interface layer level to the desired radial position.
In view of the 103 guidance above, claims 36-39 are rejected under 35 U.S.C. 103 as being unpatentable over GB 616405 in view of BORGSTROM et al. (US 2008/0171645 A1) as applied to claim 35 above and further in view of HERBERG et al. (US 2013/0309376 A1).
GB 616405 does not disclose the sealing gas being an inert gas. HERBERG et al. discloses a separator 1 with a vertically-oriented drum 2 and has a rotational axis D. Drum 2 includes an inlet tube 4 which does not rotate in operation with the drum 2 and which is guided from above into the drum 2, for example. A distributor 5 is connected downstream of the inlet tube 4, by which the material to be centrifuged can be guided into the drum 2. A disc stack 6, including a plurality of conical discs 7, is arranged in the drum 2. The discharge of fluid phases from the drum 2, of which there are two, for example, occurs via two peeling discs or grippers 8, 9, to which discharge lines 10, 11 are assigned and which are respectively arranged in gripper chambers 12, 13 which are disposed vertically on top of one another. The grippers 8, 9 stand still in operation and do not co-rotate with the drum 2. The lighter fluid phase will be discharged radially to the inside and then conducted by the first gripper 8 out of the rotating system, while the second fluid phase, which is heavier in comparison with the first fluid phase, is conducted via a separating disc or a channel 14 in a drum cover 26 to the second gripper chamber 13. The discharge of the heavier fluid phase occurs via second gripper 9 from the second gripper chamber 13. The heavier fluid phase can, for example, be a still flowable pulp or yeast suspension, as is obtained, for example, in the processing of suspensions containing solid particles such as excess yeast or sludge from breweries or wineries and fruit/citrus juices. For the discharge of further solids accumulating in the solids space 15, a piston slide valve 16 is used, as shown in FIG. 2. The piston slide valve 16 can be actuated pneumatically or hydraulically (not shown) and releases or closes solids discharge openings 17.
The upper region of the separator 1 in FIG. 2 may be replaced by a construction or embodiment as shown in FIG. 1. All other elements of the separator 1, such as inlet 4, distributor 5, disc stack 6, the slide valve 16, for example, are still present in the embodiment of FIG. 1. For example, in FIG. 1 there are still two grippers 8, 9 which do not rotate in operation with the drum 2 for discharging two flowable phases.
Different than shown in FIG. 2, in FIG. 1 the grippers 8, 9 and the gripper chambers 12, 13 are not stacked vertically above one another but rather are located at virtually the same vertical height. The first gripper chamber 12 for the first gripper 8 for the lighter fluid phase discharged to the inside is arranged further to the inside, that is, radially, relative to the rotational axis D. The second gripper chamber 13 for the second gripper 9 for the heavy flowable phase which is tapped further to the outside is arranged further to the outside, that is, radially, in the drum 2. The radial offset of the gripper chambers 12, 13, which extend annularly about the rotational axis D, shall be understood in such a way that the two gripper chambers 12, 13 extend on different radii in an circular annular, or circular, or ring-like manner about the rotational axis D. As a result, the two gripper chambers 12, 13 are disposed coaxially with respect to each other. The two gripper chambers 12, 13 are further disposed in a partially axially offset manner with respect to each other, which is an advantageous embodiment in accordance with the present disclosure.
The two gripper chambers 12, 13 are arranged in the rotating drum 2. There are shafts 19, 20 of the grippers 8, 9, respectively, that are guided upwardly out of the drum 2. The gripper chambers 12, 13 are, respectively, enclosed by gripper chamber covers 23, 24, with the outer gripper 9 including its own gripper chamber cover 24 which does not co-rotate in operation and which is disposed vertically above the gripper chamber cover 23 which rotates in operation and which is configured to be formed by an upper section of the drum cover 26. An annular chamber 21 is formed between the outside circumference of the inner gripper shaft 19 and the inner circumference of the outer gripper shaft 20. A fluid, such as an inert gas, can be introduced into chamber 21 through a channel 22 in the vertically upper gripper chamber cover 24 and through which chamber 21 the two shafts 19, 20 pass outside of the rotating system. The inert gas can be pressed from the chamber 21 into the gripper chambers 12, 13 of the rotating system, and particularly beneath the outer gripper 9. The annular chamber 21 is arranged axially above the two gripper chambers 12, 13, with regard to the vertical rotational axis D. The annular chamber 21 is connected to gripper chambers 12, 13 by fluid paths 27, 28, respectively. Fluid paths 27, 28 originate from a bottom of chamber 21 and are arranged in an annular way beneath the chamber 21 between an inner circumference of a bottom of gripper chamber cover 23, which, for example, rotates during an operation of the drum 2, and peeling disc shaft 19, which is stationary in an operation. The annular chamber 21 is further arranged between an outside circumference of the gripper chamber cover 23 and an inner circumference of outer peeling disc shaft 20, which is stationary during an operation of the drum 2.
By injecting inert gas, such as CO2, air or oxygen is prevented, in a simple but effective manner, from entering the gripper chambers 12, 13, and particularly the inner gripper chamber 12 for tapping the actual product. This is advantageous, for example, in the clarification of the beer from yeast, because no oxygen can reach the product, that is, the beer. If discharges of the separator drum 2 are performed, a negative pressure can occur in the drum 2 which is compensated by the inert gas. An additional space 25 is arranged between the cover 3 and the drum 2. Additional space 25, in accordance with the present disclosure, can also be supplied with an inert gas such as CO2. The inert gas may, for example, be provided by an optional feed (not shown).
It would have been obvious to one skilled in the art before the effective filing date of the invention to have provided the method of modified GB ‘405 such that the sealing gas is an inert gas as taught by HERBERG et al. for the purpose of preventing oxygen from contacting the substances being separated via the inert gas, as noted above.
With regard to claims 38 and 39, under BRI, the sealing gas can be deemed supplied and/or discharged as a function of a rotational speed of the rotatably mounted drum or as a function of a filling level of the annular space since the sealing gas is not supplied when the centrifuge is not in operation, i.e., the drum is stationary having a rotational speed of zero and the drum is empty thus having a zero filling level and conversely the sealing gas is intended to be supplied during operation/rotation of the drum when the rotational speed is greater than zero and when the drum is concurrently filled to some degree with the substances to be separated thus requiring injection of the sealing gas to protect said substances from oxidation.
Allowable Subject Matter
No claims stand allowed.
Conclusion
The prior art made of record and not relied upon is considered pertinent to applicant's disclosure. The cited prior art discloses drum type centrifuges, some with fluid sealing arrangements.
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/CHARLES COOLEY/
Examiner, Art Unit 1774
DATED: 18 AUG 2026
Prosecution Insights