DETAILED ACTION
Claim Rejections - 35 USC § 102
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.
Claim(s) 1, 2, 4, 7, 9, 10, 12, 13, 17, 18, 20, 23-26 is/are rejected under 35 U.S.C. 102a1 as being anticipated by Charmet (US 20200392041 A1).
Regarding claim 1, Charmet discloses (Fig. 5 embodiment) a system for enhancing combustion in a kiln, comprising:
a kiln combustion chamber disposed within the kiln (4), the kiln combustion chamber having an atmosphere therein (paras. 68, 74);
a main burner (6) for heating the atmosphere;
a calciner assembly (3) for providing a substance to be heated into the kiln combustion chamber;
a precalciner (8+11) including a precalciner combustion chamber disposed within the precalciner for receiving a biomass fuel for combustion in the precalciner combustion chamber (paras. 7, 81), the precalciner combustion chamber in communication with the kiln combustion chamber; and
a precalciner oxygen injector (one of the two lines for delivering air from adjustment system 13 to the precalciner, e.g., the line directly connected to the reactor 8) in fluid communication with the precalciner combustion chamber for providing a first stream of oxygen for enrichment into the biomass fuel for the combustion (the precalciner oxygen injector supplies oxygen-containing air to the biomass fuel and combustion chamber, and therefore enriches the combustion process with oxygen) (para. 76).
Regarding claim 2, Charmet discloses the system of claim 1, further comprising an ancillary oxygen injector (option 1: see arrow adjacent burner 6, or option 2: see four arrows pointed into the cooler 5) for injecting a second oxygen stream (“secondary air) into air (“primary air”) heated near the main burner (the primary air from the burner 6, secondary air, and fuel mix in the chamber of the kiln 4, and this mixture first must be heated before it reaches the ignition temperature for combustion; the chamber inside the kiln is also heated from the previous combustion of air and fuel, and the primary air and second oxygen stream would be immediately heated once it enters the heated chamber) (para. 74).
Regarding claim 4, Charmet discloses the system of claim 2, further comprising a controller (“tertiary flow rate adjustment system”) in operative association with the precalciner oxygen injector and the ancillary oxygen injector for controlling an amount of oxygen provided to each of the precalciner and the air heated near the main burner (the adjustment system 13 has dampers/valves that control the distribution of air from the system 13, and controlling the degree of opening of these valves would affect the relative proportion of ancillary oxygen due to mass conservation) (paras. 43, 89, 93).
Regarding claim 7, Charmet discloses the system of claim 2, further comprising a dust box (5) in fluid communication with the air heated near the main burner, and into which the ancillary oxygen injector (see Fig. 5 showing four arrows) is directed for injecting the second oxygen stream.
Regarding claim 9, Charmet discloses the system of claim 1, wherein the biomass fuel is selected from the group consisting of nut shells, wood chips (paras. 7, 8), wood pellets (paras. 7, 8), sawdust, bark, straw, rice husks, sun flower seed husks, and combinations thereof. Moreover, the system of claim 1 is capable of burning any of the recited biomass fuels).
Regarding claim 10, Charmet discloses the system of claim 1, wherein an alternative fuel (waste; para. 7) is substituted for the biomass fuel or optionally wherein the alternative fuel is included with the biomass fuel, the alternative fuel selected from the group consisting of waste derived fuel from industrial waste, waste derived fuel from municipal waste, oil polluted waste, petroleum products, petroleum coke, plastics, shredded tires, cut tires, and combinations thereof.
Regarding claim 12, Charmet discloses the system of claim 1, wherein the kiln comprises a rotary kiln or optionally a rotary kiln of a production plant (para. 74).
Regarding claim 13, Charmet discloses an apparatus for enhancing combustion in a precalciner of a kiln, comprising: a precalciner oxygen injector in fluid communication with a precalciner combustion chamber at an interior of the precalciner, the precalciner combustion chamber constructed and arranged to receive a biomass fuel into which is delivered an oxygen stream from the precalciner oxygen injector for oxygen enrichment of combustion of the biomass fuel (see rejection of claim 1).
Regarding claim 17, Charmet discloses the apparatus of claim 13, wherein the biomass fuel is selected from the group consisting of nut shells, wood chips, wood pellets, sawdust, bark, straw, rice husks, sun flower seed husks, and combinations thereof (see rejection of claim 9).
Regarding claim 18, Charmet discloses the apparatus of claim 13, wherein an alternative fuel is substituted for the biomass fuel or optionally wherein the alternative fuel is included with the biomass fuel, the alternative fuel selected from the group consisting of waste derived fuel from industrial waste, waste derived fuel from municipal waste, oil polluted waste, petroleum products, petroleum coke, plastics, shredded tires, cut tires, and combinations thereof (see rejection of claim 10).
Regarding claim 20, Charmet discloses a method for enhancing combustion in a precalciner of a kiln, comprising: providing a biomass fuel into the precalciner; and delivering an oxygen stream into the precalciner for enriching combusting of the biomass fuel (see rejection of claim 1).
Regarding claim 23, Charmet discloses the method of claim 20, wherein the delivering the oxygen stream is at a location in the precalciner upstream of ignition for the combusting (the oxygen is delivered to the precalciner, then mixed with fuel, and then ignited).
Regarding claim 24, Charmet discloses the method of claim 20, wherein the biomass fuel is selected from the group consisting of nut shells, wood chips, wood pellets, sawdust, bark, straw, rice husks, sun flower seed husks, and combinations thereof (see rejection of claim 9).
Regarding claim 25, Charmet discloses the method of claim 20, wherein an alternative fuel is substituted for the biomass fuel or optionally wherein the alternative fuel is included with the biomass fuel, the alternative fuel selected from the group consisting of waste derived fuel from industrial waste, waste derived fuel from municipal waste, oil polluted waste, petroleum products, petroleum coke, plastics, shredded tires, cut tires, and combinations thereof (see rejection of claim 10).
Regarding claim 26, Charmet discloses the method of claim 20, further comprising producing a substance selected from the group consisting of cement, lime, kaolin, magnesite, dolomite, and other substances used in refractory industries from the combusting the biomass fuel (see para. 1).
Claim Rejections - 35 USC § 103
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.
The factual inquiries for establishing a background for determining obviousness under 35 U.S.C. 103 are summarized as follows:
1. Determining the scope and contents of the prior art.
2. Ascertaining the differences between the prior art and the claims at issue.
3. Resolving the level of ordinary skill in the pertinent art.
4. Considering objective evidence present in the application indicating obviousness or nonobviousness.
Claim(s) 3 is/are rejected under 35 U.S.C. 103 as being unpatentable over Charmet (US 20200392041 A1) in view of Okazaki (US 20110053102 A1).
Regarding 3, Charmet disclose the system of claim 2, except wherein the ancillary oxygen injector is constructed and arranged for the second oxygen stream to be injected comprising a first stream portion at a first velocity, and a second stream portion at a second velocity not greater than or optionally lesser than the first velocity, the second stream portion adapted to provide a shroud for at least part of the first stream portion to protect the ancillary oxygen injector.
However, Okazaki teaches a burner, wherein an ancillary oxygen injector is constructed and arranged for the second oxygen stream to be injected comprising a first stream portion (Fig. 1, 48) at a first velocity, and a second stream portion (Fig. 1, 49) at a second velocity not greater than or optionally lesser than the first velocity (adjustment of the valves 38 and 40 would affect the relative velocities of the first and second velocities) (para. 66), the second stream portion adapted to provide a shroud for at least part of the first stream portion to protect the ancillary oxygen injector (the air would help cool the surfaces of the burner from the central flame) (Fig. 1).
It would have been obvious to a person skilled in the art at the time of effective filing of the application to modify Charmet wherein the ancillary oxygen injector is constructed and arranged for the second oxygen stream to be injected comprising a first stream portion at a first velocity, and a second stream portion at a second velocity not greater than or optionally lesser than the first velocity, the second stream portion adapted to provide a shroud for at least part of the first stream portion to protect the ancillary oxygen injector. With the modification, the second oxygen stream would surround the fuel stream. The modification provides several advantages. First, it provides control over the relative proportion of air and fuel, thereby promoting more complete combustion. Second, the secondary oxygen stream surrounding the fuel would stage the combustion, thereby reducing NOx emissions. And third, the modification provides for improved flame control (see paras. 8, 32, 90 in Okazaki), resulting in more stable and complete combustion.
Claim(s) 5, 6, 8, 14-16, 21, 22 is/are rejected under 35 U.S.C. 103 as being unpatentable over Charmet (US 20200392041 A1) in view of Demuth (EP 2881377 A1).
Regarding claim 5, Charmet discloses the system of claim 4, further comprising a tertiary air duct (one or more of the ducts leading extending from the adjustment system 13) for receiving the air heated by the main burner for delivery to the precalciner combustion chamber proximate the biomass fuel (the fuel combusted from the main burner 6 is used in the cooler 5 to preheat the tertiary air) EXCEPT where the tertiary air duct receives a second oxygen stream to create a preheated oxygen enhanced tertiary air.
However, Demuth teaches a kiln for the production of cement clinker, comprising a precalciner (Fig. 1, 5), and a tertiary air duct for supplying oxygen enhanced tertiary air to the precalciner combustion chamber (air and oxygen are mixed in the tertiary air duct) (see English translation, pg. 5).
It would have been obvious to a person skilled in the art at the time of effective filing of the application to modify Charmet where the tertiary air is mixed with oxygen to create preheated oxygen enhanced tertiary air, in order to enhance combustion efficiency and to suppress the formation of CO (see pg. 2 of Demuth, “According to the method…”).
Regarding claim 6, modified Charmet discloses (see Charmet for citations) the system of claim 5, wherein the tertiary air duct (Fig. 5: duct extending upward from adjustment system 13 and leading to the reactor 11) further comprises a tertiary air branch (vertical portion of the tertiary air duct) interconnecting and in fluid communication with the tertiary air duct (horizontal section of the tertiary air duct) and an inlet to the precalciner for delivering the preheated, oxygen enhanced tertiary air to the precalciner combustion chamber (see Fig. 5).
Regarding claim 8, Charmet discloses the system of claim 7, wherein a longitudinal axis of the ancillary oxygen injector is in registration (i.e., in the same direction or in fluid communication) with another longitudinal axis of the tertiary air duct (Fig. 5 shows both the ancillary oxygen injector and the tertiary air duct are pointing upward; therefore, both have longitudinal axes in the vertical direction).
Regarding claim 14, Charmet discloses the apparatus of claim 13, further comprising: an ancillary oxygen injector for delivering an ancillary oxygen stream into heated air near a main burner of the kiln (see rejection of claim 2); and a tertiary air duct in fluid communication with the heated air for delivering the heated, oxygen enhanced air to the interior of the precalciner (see rejection of claim 5).
Regarding claim 15, Charmet discloses the apparatus of claim 14, further comprising a controller operatively associated with the precalciner oxygen injector and the ancillary oxygen injector for controlling an amount of oxygen provided to each of the precalciner and the heated air (see rejection of claim 4).
Regarding claim 16, Charmet discloses the apparatus of claim 14, wherein a longitudinal axis of the ancillary oxygen injector is in registration with another longitudinal axis of the tertiary air duct (see rejection of claim 8).
Regarding claim 21, modified Charmet discloses the method of claim 20, further comprising: delivering an ancillary oxygen stream (Fig. 5 of Charmet shows an air stream from the cooler 5, adjacent the main burner 6) into heated air (see rejection of claim 2) near a main burner of the kiln for providing a heated, oxygen enhanced tertiary air stream (see rejection of claim 5 regarding the oxygen enhanced tertiary air stream) (the ancillary air stream is used to combust the solid fuel and the hot combusted solid fuel is sent to the cooler 5 for heating the tertiary air stream); and delivering the heated, oxygen enhanced tertiary air stream through a duct into the precalciner for the combusting.
Regarding 22, Charmet discloses the method of claim 21, further comprising controlling an amount of the oxygen stream being delivered to the precalciner, and an amount of the ancillary oxygen stream being delivered to the heated air near the main burner (see rejection of claim 4).
Claim(s) 11, 19 is/are rejected under 35 U.S.C. 103 as being unpatentable over Charmet (US 20200392041 A1) in view of Nielsen (GB 2198508 A).
Regarding 11, Charmet discloses the system of claim 1, except further comprising a sensor operatively associated with the precalciner for sensing a temperature within the precalciner combustion chamber.
However, Nielsen teaches a kiln combustion system, comprising a sensor (18) operatively associated with the precalciner (2) for sensing a temperature within the precalciner combustion chamber (pg. 3, line 33 – pg. 4, line 4).
It would have been obvious to a person skilled in the art at the time of effective filing of the application to modify Charmet to include a sensor operatively associated with the precalciner for sensing a temperature within the precalciner combustion chamber. The motivation to combine is so that the system can optimally control the temperature in the precalciner by sensing the temperature in the chamber, and adjusting the fuel flow rate based on the sensed temperature, as taught by Nielson (see para. 79 of Charmet disclosing an optimal temperature for the precalciner 8).
Regarding 19, Charmet discloses the system of claim 13, except further comprising a sensor operatively associated with the precalciner for sensing a temperature within the precalciner combustion chamber. However, see the modification made for the rejection of claim 11.
Response to Arguments
Applicant asserts the following on page(s) 10 of the 4/20/2026 Remarks:
PNG
media_image1.png
136
596
media_image1.png
Greyscale
Examiner’s response:
Charmet discloses where the precalciner oxygen injector supplies oxygen-containing air to the biomass fuel and combustion chamber, and therefore enriches the combustion process with oxygen. If the air from the injector were not supplied, then the combustion process would be starved of oxygen, resulting in incomplete combustion.
Applicant asserts the following on page(s) 11 of the 4/20/2026 Remarks:
PNG
media_image2.png
442
590
media_image2.png
Greyscale
Examiner’s response:
Okazaki discloses enveloping the flame with a shroud of relatively cooler combustion air (49). The cooler air would protect the face of the injector from the high heat of the centrally located flame.
Applicant asserts the following on page(s) 11-12 of the 4/20/2026 Remarks:
PNG
media_image3.png
586
590
media_image3.png
Greyscale
Examiner’s response:
First, the modification does not replace the Charmet burner with the Okazaki burner. Second, the rejection provides the motivation for making the modification, which is different from the one stated by Applicant. Third, Applicant provides no reason why the combination would destroy the burner of Charmet.
Applicant asserts the following on page(s) 12-13 of the 4/20/2026 Remarks:
PNG
media_image4.png
388
600
media_image4.png
Greyscale
PNG
media_image5.png
244
586
media_image5.png
Greyscale
Examiner’s response:
Charmet discloses all of the limitations in claim 5 except where the tertiary air duct receives an oxygen stream to create an oxygen-enhanced tertiary air stream. Demuth was used to teach this missing limitation.
Conclusion
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 JASON LAU whose telephone number is (571)270-7644. The examiner can normally be reached Mon-Fri 8:00-5:00.
Examiner interviews are available via telephone, in-person, and video conferencing using a USPTO supplied web-based collaboration tool. To schedule an interview, applicant is encouraged to use the USPTO Automated Interview Request (AIR) at http://www.uspto.gov/interviewpractice.
If attempts to reach the examiner by telephone are unsuccessful, the examiner’s supervisor, Michael Hoang can be reached at 571-272-6460. The fax phone number for the organization where this application or proceeding is assigned is 571-273-8300.
Information regarding the status of published or unpublished applications may be obtained from Patent Center. Unpublished application information in Patent Center is available to registered users. To file and manage patent submissions in Patent Center, visit: https://patentcenter.uspto.gov. Visit https://www.uspto.gov/patents/apply/patent-center for more information about Patent Center and https://www.uspto.gov/patents/docx for information about filing in DOCX format. For additional questions, contact the Electronic Business Center (EBC) at 866-217-9197 (toll-free). If you would like assistance from a USPTO Customer Service Representative, call 800-786-9199 (IN USA OR CANADA) or 571-272-1000.
/JASON LAU/Primary Examiner, Art Unit 3762
Prosecution Insights