DETAILED ACTION
This is in response to the Request for Continued Examination filed 10/22/2025 wherein claims 5, 8, 10-12, 16-17, and 19 are withdrawn and claims 1-4, 6-7, 9, 13-15, 18, and 20-23 are presented for examination.
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 .
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 (i.e., changing from AIA to pre-AIA ) 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.
Drawings
The drawings were received on 10/22/2025. These drawings are acceptable.
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.
Claims 1-4, 6-7, 9, and 22 are rejected under 35 U.S.C. 103 as being unpatentable over Althaus et al. (US 5,687,571) in view of Buchheim (US 4,192,139), Boardman et al. (US 2019/0212009), and Hughes et al. (US 2023/0136865).
Regarding Independent Claim 1, Althaus teaches (Figures 1-5) a combustion section (60) for a turbine engine (Column 1, lines 15-31), the combustion section (60) comprising:
a primary combustor liner (63) including an inner liner and an outer liner (the inner and outer walls of the annular combustion chamber; see Column 2, lines 55-64 and Figures 1-2);
a dome wall (54) extending between the inner liner and the outer liner (the inner and outer walls of the annular combustion chamber; see Column 2, lines 55-64 and Figures 1-2);
a primary dome inlet (at 118) located in the dome wall (54) and defining a first centerline (51, 52), wherein the outer liner (the radially outer wall of the annular combustion chamber; see Column 2, lines 55-64 and Figures 1-2) defines at least one opening (annotated below) downstream from (see Figure 1) the primary dome inlet (at 118);
a primary combustor (at the outlet of 110) having a primary combustion chamber (62) defined at least in part by the inner liner (the inner wall of the annular combustion chamber; see Figures 1-2), the outer liner (the outer wall of the annular combustion chamber; see Figures 1-2), and the dome wall (54); and
a set of secondary combustors (at the outlet of 150) including at least one secondary combustion chamber (annotated below) fluidly coupled to the primary combustion chamber (see Figures 1-2) at the at least one opening (annotated below); and
wherein the at least one secondary combustion chamber (at 150) includes a mini fuel injector (121).
Althaus does not teach at least one dilution opening located in the inner liner and defining a dilution centerline intersecting the first centerline to define a dilution angle opening away from the primary dome inlet and being 90 degrees or greater, wherein the mini fuel injector comprises a swirler having a swirl number less than 1, or wherein at least one of the primary combustor or at least one secondary combustor of the set of secondary combustors is configured to receive hydrogen fuel.
Buchheim teaches (Figures 1-4) a combustion section for a turbine engine (see title and abstract) having a primary combustor (2) having a primary combustion chamber (at 14) and a set of secondary combustors (4) including at least one secondary combustion chamber (19) fluidly coupled to the primary combustion chamber (14) at an opening (at 25, 30) in an outer liner (see Figure 1), and a dilution opening (at 17 or 31) located in the inner liner (see Figure 1) and defining a dilution centerline (annotated below) intersecting a first centerline (annotated below) to define a dilution angle opening away from the primary dome inlet (see annotation below) and being 90 degrees or greater (see annotation below).
It would have been obvious to one having ordinary skill in the art before the effective filing date of the claimed invention to modify Althaus to have at least one dilution opening located in the inner liner and defining a dilution centerline intersecting the first centerline to define a dilution angle opening away from the primary dome inlet and being 90 degrees or greater, as taught by Buccheim, in order to provide additional air so that a leaner fuel-ai mixture exists in the flame chamber and to provide cooling of the exhaust gases to the allowed turbine inlet temperature (Column 3, lines 1-10 of Buccheim). Althaus in view of Bucchiem does not teach that the mini fuel injector of the secondary combustion chamber comprises a swirler having a swirl number less than 1, or wherein at least one of the primary combustor or at least one secondary combustor of the set of secondary combustors is configured to receive hydrogen fuel.
Boardman teaches (Figures 1-11) a fuel injector (300) of a secondary combustion chamber (at 67) includes a swirler (see Figure 4) having a swirl number less than 1 (between approximately 0.2 and approximately 0.3; see Paragraph 0076).
It would have been obvious to one having ordinary skill in the art before the effective filing date of the claimed invention to modify Althaus in view of Bucchiem to have the fuel injector of the secondary combustion chamber comprise a swirler having a swirl number less than 1, as taught by Boardman, in order to prevent vortex breakdown and prevent centerline reverse flow (Paragraph 0076 of Boardman). Althaus in view of Bucchiem and Boardman does not teach wherein at least one of the primary combustor or at least one secondary combustor of the set of secondary combustors is configured to receive hydrogen fuel.
Hughes teaches (Figures 1-9) first and second combustion zones (see Figure 2), wherein hydrogen is burned within the combustor (see Paragraph 0005).
It would have been obvious to one having ordinary skill in the art before the effective filing date of the claimed invention to modify Althaus in view of Bucchiem and Boardman to use hydrogen as fuel in the combustor, as taught by Hughes, in order to significantly reduce or eliminate the emission of NOx and other pollutants (Paragraph 0005).
It is additionally noted that the actions of the fluid are intended use recitations – “inclusion of material or article worked upon by a structure being claimed does not impart patentability to the claims” (MPEP 2115 [R-2]). In this case, the fuel is considered the material or article worked upon and does not impart patentability to the claims.
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Regarding Claim 2, Althaus in view of Buccheim, Boardman, and Hughes teaches the invention as claimed and as discussed above. Althaus further teaches (Figures 1-5) a mini dome wall (74) radially spaced from the outer liner (the radially outer wall of the annular combustion chamber; see Column 2, lines 55-64 and Figures 1-2) and further defining the at least one secondary combustion chamber (annotated above) and a mini dome inlet (at 158) located in the mini dome wall (74) and fluidly coupled to (see Figure 1 and Column 3, lines 19-30) the at least one secondary combustion chamber (annotated above).
Regarding Claim 3, Althaus in view of Buccheim, Boardman, and Hughes teaches the invention as claimed and as discussed above. Althaus further teaches (Figures 1-5) a primary fuel injector (120) fluidly coupled to (see Figure 1) the primary dome inlet (at 118) and the mini fuel injector (121) fluidly coupled to (see Figure 1) the mini dome inlet (at 158).
Regarding Claim 4, Althaus in view of Buccheim, Boardman, and Hughes teaches the invention as claimed and as discussed above. Althaus further teaches (Figures 1-5) wherein the mini dome inlet (at 158) defines a second centerline (53) that intersects the first centerline (51) to define a primary combustor angle (the angle made by the intersection of 51 and 53) opens towards the primary dome inlet and being 90 degrees or less (the longitudinal axes of the secondary burners being perpendicular to the longitudinal axis of the primary burner; see Figure 1 and Column 3, lines 13-18).
Regarding Claim 6, Althaus in view of Buccheim, Boardman, and Hughes teaches the invention as claimed and as discussed above. Althaus in view of Buccheim, Boardman, and Hughes does not teach, as discussed so far, wherein the dilution centerline and the second centerline are unaligned.
Buchheim teaches (Figures 1-4) a combustion section for a turbine engine (see title and abstract) having a primary combustor (2) having a primary combustion chamber (at 14) and a set of secondary combustors (4) including at least one secondary combustion chamber (19) fluidly coupled to the primary combustion chamber (14) at an opening (at 25, 30) in an outer liner (see Figure 1), and a dilution opening (at 17 or 31) located in the inner liner (see Figure 1), wherein the dilution centerline (a centerline through 17 or 31; see annotation above) and the second centerline (a centerline through passage 30; see Figure 1) are unaligned (see annotation above).
It would have been obvious to one having ordinary skill in the art before the effective filing date of the claimed invention to modify Althaus in view of Buccheim, Boardman, and Hughes to have at least one dilution opening located in the inner liner, wherein the dilution centerline and the second centerline are unaligned, as taught by Buccheim, for the same reasons discussed above in claim 1.
Regarding Claim 7, Althaus in view of Buccheim, Boardman, and Hughes teaches the invention as claimed and as discussed above. Althaus in view of Buccheim, Boardman, and Hughes does not teach, as discussed so far, wherein the dilution centerline is downstream of the second centerline.
Buchheim teaches (Figures 1-4) a combustion section for a turbine engine (see title and abstract) having a primary combustor (2) having a primary combustion chamber (at 14) and a set of secondary combustors (4) including at least one secondary combustion chamber (19) fluidly coupled to the primary combustion chamber (14) at an opening (at 25, 30) in an outer liner (see Figure 1), and a dilution opening (at 17 or 31) located in the inner liner (see Figure 1), wherein the dilution centerline (a centerline through 17 or 31; see annotation above) is downstream of the second centerline (a centerline through passage 30; see Figure 1).
It would have been obvious to one having ordinary skill in the art before the effective filing date of the claimed invention to modify Althaus in view of Buccheim, Boardman, and Hughes to have at least one dilution opening located in the inner liner, wherein the dilution centerline is downstream of the second centerline, as taught by Buccheim, for the same reasons discussed above in claim 1.
Regarding Claim 9, Althaus in view of Buccheim, Boardman, and Hughes teaches the invention as claimed and as discussed above. Althaus in view of Buccheim, Boardman, and Hughes does not teach, as discussed so far, wherein the at least one secondary combustion chamber is directed toward the primary dome inlet and the primary combustor angle is less than 90 degrees.
Buchheim teaches (Figures 1-4) a combustion section for a turbine engine (see title and abstract) having a primary combustor (2) having a primary combustion chamber (at 14) and a set of secondary combustors (4) including at least one secondary combustion chamber (19) fluidly coupled to the primary combustion chamber (14) at an opening (at 25, 30) in an outer liner (see Figure 1), wherein the at least one secondary combustion chamber (19) is directed toward (via passage 30) the primary dome inlet (at 13) and the primary combustor angle is less than 90 degrees (see annotation below).
It would have been obvious to one having ordinary skill in the art before the effective filing date of the claimed invention to modify Althaus in view of Buccheim, Boardman, and Hughes to have the at least one secondary combustion chamber is directed toward the primary dome inlet and the primary combustor angle is less than 90 degrees, as taught by Buccheim, in order to direct the auxiliary flame into the flame chamber to promote efficient and complete combustion in the flame chamber (Column 3, lines 25-30 of Buccheim).
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Regarding Claim 22, Althaus in view of Buccheim, Boardman, and Hughes teaches the invention as claimed and as discussed above. Althaus in view of Buccheim, Boardman, and Hughes does not teach, as discussed so far, wherein the combustion section is configured to operate with hydrogen fuel such that secondary exhaust gases are recirculated into the primary combustion chamber to reduce flame temperature and nitrogen oxide emissions.
Buchheim teaches (Figures 1-4) the combustion section (see Figure 1) is configured to operate with fuel (from 8 and 20) such that the secondary exhaust gases (from 30) are recirculated into the primary combustion chamber (at 14).
It would have been obvious to one having ordinary skill in the art before the effective filing date of the claimed invention to modify Althaus in view of Buccheim, Boardman, and Hughes to have the combustion section be configured to operate with fuel such that the secondary exhaust gases are recirculated into the primary combustion chamber, as taught by Buccheim, in order to direct the auxiliary flame into the flame chamber to promote efficient and complete combustion in the flame chamber (Column 3, lines 25-30 of Buccheim).
Hughes teaches (Figures 1-9) using hydrogen as fuel in a combustor (see Paragraph 0005), which allows for the reduction in flame temperature and nitrogen oxide emissions (see Paragraphs 0005 and 0045).
As discussed above, it would have been obvious to one having ordinary skill in the art before the effective filing date of the claimed invention to modify Althaus in view of Buccheim, Boardman, and Hughes to use hydrogen as fuel in the combustor, as taught by Hughes, in order to significantly reduce or eliminate the emission of NOx and other pollutants (Paragraph 0005).
It is additionally noted, regarding the phrase “to reduce flame temperature and nitrogen oxide emissions”, that "apparatus claims cover what a device is, not what a device does." Hewlett-Packard Co. v. Bausch & Lomb Inc., 909 F.2d 1464, 1469, 15 USPQ2d 1525, 1528 (Fed. Cir. 1990) (emphasis in original). A claim containing a "recitation with respect to the manner in which a claimed apparatus is intended to be employed does not differentiate the claimed apparatus from a prior art apparatus" if the prior art apparatus teaches all the structural limitations of the claim. Ex parte Masham, 2 USPQ2d 1647 (Bd. Pat. App. & Inter. 1987).
Claim 13 is rejected under 35 U.S.C. 103 as being unpatentable over Althaus et al. (US 5,687,571) in view of Buchheim (US 4,192,139), Boardman et al. (US 2019/0212009), and Hughes et al. (US 2023/0136865) as applied to claim 1 above, and further in view of Prociw et al. (US 2014/0260297).
Regarding Claim 13, Althaus in view of Buccheim, Boardman, and Hughes teaches the invention as claimed and as discussed above. Althaus in view of Buccheim, Boardman, and Hughes does not teach, as discussed so far, wherein a radial line extending from an engine centerline of the turbine engine intersects with a geometric center of the at least one dilution opening in a transverse plane and the radial line and the dilution centerline are angled with respect to each other to form a tangential angle ranging from -180 degrees to 180 degrees.
Prociw teaches (Figures 1-4) a radial line (R) extending from an engine centerline (X; see Figures 1 and 4) intersects with a geometric center (DZ) of the at least one dilution opening (26, 36) in a transverse plane and the radial line (R) and the dilution centerline (DZ) are angled with respect to each other (see Figure 4) to form a tangential angle ranging from -180 degrees to 180 degrees (see Figure 4 and Paragraph 0019).
It would have been obvious to one having ordinary skill in the art before the effective filing date of the claimed invention to modify Althaus in view of Buccheim, Boardman, and Hughes to have a radial line extending from an engine centerline of the turbine engine intersects with a geometric center of the at least one dilution opening in a transverse plane and the radial line and the dilution centerline are angled with respect to each other to form a tangential angle ranging from -180 degrees to 180 degrees, as taught by Prociw, in order to enhance fluid mixing to render the fuel and air mixture more uniform, which may lead to keeping the flame temperature relatively low (Paragraph 0019 of Prociw).
Claim 14 is rejected under 35 U.S.C. 103 as being unpatentable over Althaus et al. (US 5,687,571) in view of Buchheim (US 4,192,139), Boardman et al. (US 2019/0212009), and Hughes et al. (US 2023/0136865) as applied to claim 1 above, and further in view of Venkatesan et al. (US 2019/0017441).
Regarding Claim 14, Althaus in view of Buccheim, Boardman, and Hughes teaches the invention as claimed and as discussed above. Althaus in view of Buccheim, Boardman, and Hughes does not teach, as discussed so far, wherein the at least one secondary combustion chamber is a plurality of secondary combustion chambers circumferentially arranged about the outer liner, and the at least one dilution opening is a plurality of dilution openings circumferentially arranged about the inner liner.
Venkatesan teaches (Figures 1-8) at least one secondary combustion chamber (150) arranged on an outer liner (104) of a combustor (16), wherein the at least one secondary combustion chamber (150) is a plurality of secondary combustion chambers circumferentially arranged (the multiple cavities may be isolated from each other and spaced apart at different locations along the circumference of the outer liner; see Paragraph 0033) about the outer liner (104), and at least one opening (openings in liner 106; see Figure 3) is at least a plurality of openings (see Figure 3) circumferentially arranged about the inner liner (106).
It would have been obvious to one having ordinary skill in the art before the effective filing date of the claimed invention to modify Althaus in view of Buccheim, Boardman, and Hughes to have the at least one secondary combustion chamber be a plurality of secondary combustion chambers circumferentially arranged about the outer liner, and at least one opening being a plurality of openings circumferentially arranged about the inner liner, as taught by Venkatesan, since Venkatesan teaches that the secondary combustion chamber may be either a singular annular cavity surrounding the outer liner or may be a plurality of cavities arranged along the circumference of the outer liner and it has been held the variations in shape were a matter of choice and only involves routine skill in the art. See In re Dailey, 357 F.2d 669, 149 USPQ (CCPA 1966). It is further noted that a simple substitution of one known element (in this case, an annular combustion chamber arranged along the circumference of the outer liner, as taught by Althaus and Venkatesan) for another (in this case, a plurality of combustion chambers arranged along the circumference of the outer liner, as taught by Venkatesan) to obtain predictable results (in this case, to provide products of combustion to the main combustion chamber) was an obvious extension of prior art teachings, KSR, 550 U.S. at 415-421, 82 USPQ2d at 1396, MPEP 2141 III B.
It is noted that Buccheim also teaches (Figures 1-4) that dilution openings 17 and dilution openings 31 each comprise a plurality of openings (see Column 3, lines 1-10 of Buccheim).
It would have been obvious to one having ordinary skill in the art before the effective filing date of the claimed invention to modify Althaus in view of Buccheim, Boardman, Hughes, and Venkatesan to include the plurality of dilution openings, as taught by Buccheim, in order to provide additional air to the flame chamber so that the mixture within is lean and so that the exhaust gases are cooled to the allowed turbine inlet temperature (Column 3, lines 1-10 of Buccheim).
Claim 15 is rejected under 35 U.S.C. 103 as being unpatentable over Althaus et al. (US 5,687,571) in view of Buchheim (US 4,192,139), Boardman et al. (US 2019/0212009), Hughes et al. (US 2023/0136865), and Venkatesan et al. (US 2019/0017441) as applied to claim 14 above, and further in view of Campion et al. (US 2009/0100840).
Regarding Claim 15, Althaus in view of Buccheim, Boardman, Hughes, and Venkatesan teaches the invention as claimed and as discussed above. Althaus in view of Buccheim, Boardman, Hughes, and Venkatesan does not teach, as discussed so far, wherein the plurality of dilution openings are circumferentially staggered with respect to the plurality of secondary combustion chambers.
Campion teaches (Figures 1-9) that the distribution of the primary holes and dilution holes on the circumference of the walls of the chamber constitute important parameters that can be modified to adjust the temperature distribution at the discharge from the chamber and to reduce polluting emissions from the chamber (Paragraph 0010 of Campion). Therefore, the circumferential spacing of the dilution openings are recognized as result-effective variables, i.e. variables which achieve a recognized result. In re Antonie, 559 F.2d 618, 195 USPQ 6 (CCPA 1977); MPEP 2144.05(II)(B). In this case, the recognized result is that modifying the circumferential positions of the dilution openings leads to a change in the temperature distribution at the discharge of the chamber and a reduction in emissions from the chamber.
Therefore, since the general conditions of the claim, i.e. that the circumferential spacing of the dilution openings can be adjusted to change the temperature distribution and reduce emissions, were taught in the prior art by Campion, it is not inventive to discover the optimum workable range by routine experimentation, and it would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to provide the spacing of the dilution openings as taught by Campion in order to alter the temperature distribution at the exit of the chamber and to reduce emissions. It has been held that “[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, 220 F.2d 454, 456, 105 USPQ 233, 235 (CCPA 1955); MPEP 2144.05(II)(A).
Claim 18 is rejected under 35 U.S.C. 103 as being unpatentable over Althaus et al. (US 5,687,571) in view of Buchheim (US 4,192,139), Boardman et al. (US 2019/0212009), and Hughes et al. (US 2023/0136865) as applied to claim 1 above, and further in view of Campion et al. (US 2009/0100840).
Regarding Claim 18, Althaus in view of Buccheim, Boardman, and Hughes teaches the invention as claimed and as discussed above. Althaus in view of Buccheim, Boardman, and Hughes does not teach, as discussed so far, wherein the set of secondary combustors comprise an aft face and the at least one dilution opening defines a diameter and comprises a forward face spaced from the aft face an axial distance from -10D to +20D.
Buccheim teaches (Figures 1-4) the set of secondary combustors (at 25) comprise an aft face (annotated below) and the at least one dilution opening (17 or 31) defines a diameter (the diameter of opening 17 or 31) and comprises a forward face (annotated below) spaced from the aft face (see annotation below).
It would have been obvious to one having ordinary skill in the art before the effective filing date of the claimed invention to modify Althaus in view of Buccheim, Boardman, and Hughes to have the set of secondary combustors comprise an aft face and the at least one dilution opening defines a diameter and comprises a forward face spaced from the aft face, as taught by Buccheim, for the same reasons discussed above in claim 1. Althaus in view of Buccheim and Boardman does not teach that the dilution opening is spaced an axial distance from -10D to +20D.
Campion teaches (Figures 1-9) that the axial positions of the primary holes and dilution holes and their distribution on the circumference of the walls of the chamber, constitute important parameters that can be modified to adjust the temperature distribution at the discharge from the chamber and to reduce polluting emissions from the chamber (Paragraph 0010 of Campion). Therefore, the axial spacing of the dilution openings are recognized as result-effective variables, i.e. variables which achieve a recognized result. In re Antonie, 559 F.2d 618, 195 USPQ 6 (CCPA 1977); MPEP 2144.05(II)(B). In this case, the recognized result is that modifying the axial positions of the dilution openings leads to a change in the temperature distribution at the discharge of the chamber and a reduction in emissions from the chamber.
Therefore, since the general conditions of the claim, i.e. that the axial spacing of the dilution openings can be adjusted to change the temperature distribution and reduce emissions, were taught in the prior art by Campion, it is not inventive to discover the optimum workable range by routine experimentation, and it would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to provide the spacing of the dilution openings as taught by Campion in order to alter the temperature distribution at the exit of the chamber and to reduce emissions. It has been held that “[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, 220 F.2d 454, 456, 105 USPQ 233, 235 (CCPA 1955); MPEP 2144.05(II)(A).
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Claims 20-21 are rejected under 35 U.S.C. 103 as being unpatentable over Althaus et al. (US 5,687,571) in view of Buchheim (US 4,192,139) and Hughes et al. (US 2023/0136865).
Regarding Independent Claim 20, Althaus teaches (Figures 1-5) a turbine engine (Column 1, lines 15-31), comprising:
a compressor section (Column 2, lines 55-64), a combustion section (60), and a turbine section (at 64) in serial flow arrangement along an engine centerline (inherent in gas turbine engines), the combustion section (60) comprising:
a primary combustor liner (63) including an inner liner and an outer liner (the inner and outer walls of the annular combustion chamber; see Column 2, lines 55-64 and Figures 1-2);
a dome wall (54) extending between the inner liner and the outer liner (the inner and outer walls of the annular combustion chamber; see Column 2, lines 55-64 and Figures 1-2);
a primary dome inlet (at 118) located in the dome wall (54) and defining a first centerline (51, 52), wherein the outer liner (the radially outer wall of the annular combustion chamber; see Column 2, lines 55-64 and Figures 1-2) defines at least one opening (annotated above) downstream from (see Figure 1) the primary dome inlet (at 118);
a primary combustor (at the outlet of 110) having a primary combustion chamber (62) defined at least in part by the inner liner (the inner wall of the annular combustion chamber; see Figures 1-2), the outer liner (the outer wall of the annular combustion chamber; see Figures 1-2), and the dome wall (54); and
a set of secondary combustors (at the outlet of 150) including at least one secondary combustion chamber (annotated above) fluidly coupled to the primary combustion chamber (see Figures 1-2) at the at least one opening (annotated above),
wherein a primary fuel injector (at 120) is fluidly coupled to the primary dome inlet (at 118) and a mini fuel injector (at 121) is fluidly coupled to a mini dome inlet (at 158) of the at least one secondary combustion chamber (at the outlet of 150).
Althaus does not teach at least one dilution opening located in the inner liner and defining a dilution centerline intersecting the first centerline to define a dilution angle opening away from the primary dome inlet and being 90 degrees or greater, or wherein at least one of the primary combustor or at least one secondary combustor of the set of secondary combustors is configured to receive hydrogen fuel.
Buchheim teaches (Figures 1-4) a combustion section for a turbine engine (see title and abstract) having a primary combustor (2) having a primary combustion chamber (at 14) and a set of secondary combustors (4) including at least one secondary combustion chamber (19) fluidly coupled to the primary combustion chamber (14) at an opening (at 25, 30) in an outer liner (see Figure 1), and a dilution opening (at 17 or 31) located in the inner liner (see Figure 1) and defining a dilution centerline (annotated above) intersecting a first centerline (annotated above) to define a dilution angle opening away from the primary dome inlet (see annotation above) and being 90 degrees or greater (see annotation above).
It would have been obvious to modify Althaus to have at least one dilution opening located in the inner liner and defining a dilution centerline intersecting the first centerline to define a dilution angle opening away from the primary dome inlet and being 90 degrees or greater, as taught by Buccheim, in order to provide additional air so that a leaner fuel-ai mixture exists in the flame chamber and to provide cooling of the exhaust gases to the allowed turbine inlet temperature (Column 3, lines 1-10 of Buccheim). Althaus in view of Bucchiem does not teach that at least one of the primary combustor or at least one secondary combustor of the set of secondary combustors is configured to receive hydrogen fuel.
Hughes teaches (Figures 1-9) first and second combustion zones (see Figure 2), wherein hydrogen is burned within the combustor (see Paragraph 0005).
It would have been obvious to one having ordinary skill in the art before the effective filing date of the claimed invention to modify Althaus in view of Bucchiem to use hydrogen as fuel in the combustor, as taught by Hughes, in order to significantly reduce or eliminate the emission of NOx and other pollutants (Paragraph 0005).
It is additionally noted that the actions of the fluid are intended use recitations – “inclusion of material or article worked upon by a structure being claimed does not impart patentability to the claims” (MPEP 2115 [R-2]). In this case, the fuel is considered the material or article worked upon and does not impart patentability to the claims.
Regarding Independent Claim 21, Althaus teaches (Figures 1-5) a combustion system (see Figure 1) for a turbine engine (Column 1, lines 15-31), the combustion section (see Figure 1) comprising:
a primary combustor liner (63) including an inner liner and an outer liner (the inner and outer walls of the annular combustion chamber; see Column 2, lines 55-64 and Figures 1-2);
a dome wall (54) extending between the inner liner and the outer liner (the inner and outer walls of the annular combustion chamber; see Column 2, lines 55-64 and Figures 1-2);
a primary dome inlet (at 118) located in the dome wall (54) and defining a first centerline (51, 52), wherein the outer liner (the radially outer wall of the annular combustion chamber; see Column 2, lines 55-64 and Figures 1-2) defines at least one opening (annotated above) downstream from (see Figure 1) the primary dome inlet (at 118);
a primary combustor (at the outlet of 110) having a primary combustion chamber (62) defined at least in part by the inner liner (the inner wall of the annular combustion chamber; see Figures 1-2), the outer liner (the outer wall of the annular combustion chamber; see Figures 1-2), and the dome wall (54); and
a set of secondary combustors (at the outlet of 150) including at least one secondary combustion chamber (annotated above) fluidly coupled to the primary combustion chamber (see Figures 1-2) at the at least one opening (annotated above),
wherein the plenum (50) surrounding the combustion chamber (62) receives combustion air delivered by a compressor (Column 2, lines 55-64).
Althaus does not teach at least one dilution opening located in the inner liner and defining a dilution centerline intersecting the first centerline to define a dilution angle opening away from the primary dome inlet and being 90 degrees or greater, wherein a main combustion zone of the primary combustion chamber is configured to receive exhaust gases directed from the at least one secondary combustion chamber by a dilution flow received through the at least one dilution opening, and wherein the dilution flow includes compressed air, or wherein at least one of the primary combustor or at least one secondary combustor of the set of secondary combustors is configured to receive hydrogen fuel.
Buchheim teaches (Figures 1-4) a combustion section for a turbine engine (see title and abstract) having a primary combustor (2) having a primary combustion chamber (at 14) and a set of secondary combustors (4) including at least one secondary combustion chamber (19) fluidly coupled to the primary combustion chamber (14) at an opening (at 25, 30) in an outer liner (see Figure 1), and a dilution opening (at 17 or 31) located in the inner liner (see Figure 1) and defining a dilution centerline (annotated above) intersecting a first centerline (annotated above) to define a dilution angle opening away from the primary dome inlet (see annotation above) and being 90 degrees or greater (see annotation above), wherein a main combustion zone (within 14) of the primary combustion chamber (see Figure 1) is configured to receive exhaust gases (from 30) directed from the at least one secondary combustion chamber (19) by a dilution flow (due to the angle of the dilution opening away from the primary dome inlet; see the flow arrows in Figure 1) received through the at least one dilution opening (at 17), and wherein the dilution flow includes compressed air (see Figure 1).
It would have been obvious to modify Althaus to have at least one dilution opening located in the inner liner and defining a dilution centerline intersecting the first centerline to define a dilution angle opening away from the primary dome inlet and being 90 degrees or greater, wherein a main combustion zone of the primary combustion chamber is configured to receive exhaust gases directed from the at least one secondary combustion chamber by a dilution flow received through the at least one dilution opening, and wherein the dilution flow includes compressed air, as taught by Buccheim, in order to provide additional air so that a leaner fuel-ai mixture exists in the flame chamber and to provide cooling of the exhaust gases to the allowed turbine inlet temperature (Column 3, lines 1-10 of Buccheim). It is additionally noted that “where the claimed and prior art products are identical or substantially identical in structure or composition, or are produced by identical or substantially identical processes, a prima facie case of either anticipation or obviousness has been established”. In re Best, 562 F.2d 1252, 1255, 195 USPQ 430, 433 (CCPA 1977). "When the PTO shows a sound basis for believing that the products of the applicant and the prior art are the same, the applicant has the burden of showing that they are not." In re Spada, 911 F.2d 705, 709, 15 USPQ2d 1655, 1658 (Fed. Cir. 1990).
Althaus in view of Bucchiem does not teach that at least one of the primary combustor or at least one secondary combustor of the set of secondary combustors is configured to receive hydrogen fuel.
Hughes teaches (Figures 1-9) first and second combustion zones (see Figure 2), wherein hydrogen is burned within the combustor (see Paragraph 0005).
It would have been obvious to one having ordinary skill in the art before the effective filing date of the claimed invention to modify Althaus in view of Bucchiem to use hydrogen as fuel in the combustor, as taught by Hughes, in order to significantly reduce or eliminate the emission of NOx and other pollutants (Paragraph 0005).
It is additionally noted that the actions of the fluid are intended use recitations – “inclusion of material or article worked upon by a structure being claimed does not impart patentability to the claims” (MPEP 2115 [R-2]). In this case, the fuel is considered the material or article worked upon and does not impart patentability to the claims.
Claim 23 is rejected under 35 U.S.C. 103 as being unpatentable over Althaus et al. (US 5,687,571) in view of Buchheim (US 4,192,139), Boardman et al. (US 2019/0212009), and Hughes et al. (US 2023/0136865) as applied to claim 1 above, and further in view of Huntington et al. (US 2014/0150445).
Regarding Claim 23, Althaus in view of Buccheim, Boardman, and Hughes teaches the invention as claimed and as discussed above. Althaus in view of Buccheim, Boardman, and Hughes does not teach, as discussed so far, wherein the primary combustor is configured to be operated at an equivalence ratio from about 0.5 to about 2 and the at least one secondary combustor is configured to be operated at an equivalence ratio from about 0.4 to about 1.5 to provide flame stability and reduce nitrogen oxide emissions.
Huntington teaches that stoichiometric or substantially stoichiometric may refer to an equivalence ratio of approximately 0.95 to 1.05, and the stoichiometric combustion of fuel and oxidant in a turbine-based system results in products of combustion or exhaust gas with substantially no unburnt fuel or oxidant remaining, leading to less than 1,2,3,4,or 5 percent by volume of oxidant, unburnt fuel or hydrocarbons, nitrogen oxides, carbon monoxide, sulfur oxides, hydrogen, and other products of incomplete combustion (see Paragraph 0037). Huntington further teaches that substantially stoichiometric fuel/oxidant ratios increase flame stability and reduce NOx emissions (see Paragraph 0031). Therefore, the equivalence ratios at which the combustors are operated are recognized as result-effective variables, i.e. variables which achieve a recognized result. In re Antonie, 559 F.2d 618, 195 USPQ 6 (CCPA 1977); MPEP 2144.05(II)(B). In this case, the recognized result is that modifying the equivalence ratio at which the combustors are operated to be near 1.0 leads to products of combustion or exhaust gases with substantially no unburnt fuel, oxidant, or nitrogen oxides, or other products of incomplete combustion.
Therefore, since the general conditions of the claim, i.e. that the equivalence ratio at which the combustors are operated obtain substantially stoichiometric combustion, were taught in the prior art by Huntington, it is not inventive to discover the optimum workable range by routine experimentation, and it would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to provide the equivalence ratios as taught by Huntington in order to generate products of combustion or exhaust gas with substantially no unburnt fuel or oxidant remaining, leading to less than 1,2,3,4,or 5 percent by volume of oxidant, unburnt fuel or hydrocarbons, nitrogen oxides, carbon monoxide, sulfur oxides, hydrogen, and other products of incomplete combustion (see Paragraph 0037 of Huntington). It has been held that “[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, 220 F.2d 454, 456, 105 USPQ 233, 235 (CCPA 1955); MPEP 2144.05(II)(A).
It is additionally noted, regarding the phrase “to provide flame stability and reduce nitrogen oxide emissions”, that "apparatus claims cover what a device is, not what a device does." Hewlett-Packard Co. v. Bausch & Lomb Inc., 909 F.2d 1464, 1469, 15 USPQ2d 1525, 1528 (Fed. Cir. 1990) (emphasis in original). A claim containing a "recitation with respect to the manner in which a claimed apparatus is intended to be employed does not differentiate the claimed apparatus from a prior art apparatus" if the prior art apparatus teaches all the structural limitations of the claim. Ex parte Masham, 2 USPQ2d 1647 (Bd. Pat. App. & Inter. 1987).
Response to Arguments
Applicant’s arguments with respect to claims 1-4, 6-7, 9, 13-15, 18, and 20-23 have been considered but are moot because the arguments do not apply to the new combination of references being applied in this office action, necessitated by amendment. However, to the extent possible, the arguments are addressed in the body of the rejection above, at the appropriate locations.
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/THOMAS P BURKE/Primary Examiner, Art Unit 3741