DETAILED ACTION
This is a final rejection in response to amendment filed 4/9/26. Claims 1, 3-17 are currently pending.
Response to Arguments
Applicant’s arguments with respect to claim(s) 1 and 3-17 have been considered but are moot because the new ground of rejection does not rely on any reference applied in the prior rejection of record for any teaching or matter specifically challenged in the argument.
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) 1, 3-17 is/are rejected under 35 U.S.C. 103 as being unpatentable over Ball, JR. et al. (US 20140102071) in view of Lockwood (US 3949548).
Regarding independent claim 1 and 17, Ball teaches a gas turbine system 28 comprising: an exhaust gas guide duct 36,38 provided on a downstream side of a gas turbine, and configured to guide exhaust gas discharged from the gas turbine to an outside [0017]; a recirculation line 100 connected to the exhaust gas guide duct, and configured to recirculate the exhaust gas extracted from the exhaust gas guide duct back into the exhaust gas guide duct [0022-0023]; a fuel supply line configured to supply a fuel to a combustor of the gas turbine [0026]; and a heat exchanger 50 configured to heat the fuel using the exhaust gas recirculating along the recirculation line [0019, 0022-0024].
Ball is silent to wherein the heat exchanger heats the fuel by an intermediate medium of ambient air heated by the exhaust gas.
Lockwood teaches wherein the heat exchanger heats the fuel by an intermediate medium of ambient air heated by the exhaust gas (col. 5, l. 24-34).
It would have been obvious to one of ordinary skill in the art at the time of filing to modify the engine of Ball to use ambient air heated by exhaust gas to heat fuel as taught by Lockwood.
It is noted that a simple substitution of one known element (in this case, combustion air as intermediate medium for heating fuel as taught by Ball) for another (ambient air as intermediate medium for heating fuel as taught by Lockwood) to obtain predictable results (in this case, providing intermediate thermal buffer, reducing direct exhaust to fuel contact) was an obvious extension of prior art teachings, KSR, MPEP 2141 III B.
Regarding dependent claim 3, Ball in view of Lockwood teaches the invention as claimed and discussed above. Lockwood further teaches wherein the heat exchanger 26 includes: a housing member configured such that the ambient air enters and exits; a first heat exchange part provided in the housing member, through which the recirculation line passes, and configured to heat the ambient air introduced into the housing member by heat exchange with the exhaust gas recirculating along the recirculation line; and a second heat exchange part provided in the housing member and on an upper side of upside the first heat exchange part, through which the fuel supply line passes, and configured to heat the fuel supplied along the fuel supply line by heat exchange with the ambient air having passed through the first heat exchange part (as seen in fig. 3).
Regarding dependent claim 4, Ball in view of Lockwood teaches the invention as claimed and discussed above. Ball further teaches comprising: a mixing chamber 108 provided between the first heat exchange part and the second heat exchange part, and configured to mix the ambient air having passed through the first heat exchange part, wherein the second heat exchange part heats the fuel using the ambient air having passed via the mixing chamber [0024].
Regarding dependent claim 5-8, Ball in view of Lockwood teaches the invention as claimed and discussed above. Ball in view of Lockwood is silent to wherein the exhaust gas recirculating to the exhaust gas guide duct via the first heat exchange part is defined as having a lower temperature than that of the exhaust gas introduced from the exhaust gas guide duct to the recirculation line, and wherein wherein the exhaust gas having passed via the first heat exchange part is defined as having a temperature of 200°C to 250°C, 250°C to 400°C, or 300°C to 350°C.
Ball teaches large temperature difference between the exhaust gases and the fuel as creating undesirable thermal stresses in the fuel heat exchanger, making exhaust gas temperature across the heat exchanger a result effective variable lined to the recognized result of thermal stress reduction. Lockwood further teaches efficiency is approximately 4% per 500°F drop in recycled exhaust gas temperatures can be expected using recycled exhaust cooler and fan, identifying the drop in recirculated exhaust gas temperature as a result-effective variable.
It would have been obvious to one of ordinary skill in the art at the time of the invention to modify the temperature differential across the first the heat exchange part, since it has been held that optimizing a result effective variable was an obvious extension of prior art teachings, In re Antoine, 559 F.2d 618, 195 USPQ 6 (CCPA 1977), In re Aller, 220 F.2d 454, 456, 105 USPQ 233, 235 (CCPA 1955),“[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.” MPEP 2144.05 I and II.
Regarding dependent claim 9, Ball in view of Lockwood teaches the invention as claimed and discussed above. Ball further teaches comprising: a first control valve 98 provided in the recirculation line, and configured to control flow of the exhaust gas moving from the exhaust gas guide duct to the heat exchanger [0021].
Regarding dependent claim 10, Ball in view of Lockwood teaches the invention as claimed and discussed above. Ball further teaches comprising: a second control valve 110 provided in the recirculation line, and configured to control flow of the exhaust gas moving from the heat exchanger to the exhaust gas guide duct [0022-0023].
Regarding dependent claim 11, Ball in view of Lockwood teaches the invention as claimed and discussed above. Ball further teaches wherein an inlet end 72 of the recirculation line is connected to the exhaust gas guide duct 36, and an outlet end of the recirculation line is connected to an upstream side of the exhaust gas guide duct than the inlet end [0022-0023].
Regarding dependent claim 12, Ball in view of Lockwood teaches the invention as claimed and discussed above. Ball further teaches comprising: an ejection nozzle 104 connected to an outlet end of the recirculation line, and configured to eject the exhaust gas to an interior of the exhaust gas guide duct [0022-0024].
Regarding dependent claim 13, Ball in view of Lockwood teaches the invention as claimed and discussed above. Ball further teaches wherein the fuel supply line includes: a first supply 62 line connected to the combustor 22; and a second supply line 120, which branches from the first supply line [0026], extends through the heat exchanger 50, and then merges back to the first supply line [0026].
Regarding dependent claim 14, Ball in view of Lockwood teaches the invention as claimed and discussed above. Ball further teaches comprising: a third control valve 128 provided in the first supply line at a position where the second supply line branches [0027], wherein the third control valve switches flow of the fuel such that at least a portion of the fuel selectively passes via the second supply line [0026-0027].
Regarding dependent claim 15, Ball in view of Lockwood teaches the invention as claimed and discussed above. Ball further teaches comprising: an orifice provided in the first supply line at a portion bypassing the heat exchanger [0027], and configured to adjust a flow rate of the fuel moving along the first supply line [0027].
Regarding dependent claim 16, Ball in view of Lockwood teaches the invention as claimed and discussed above. Ball further teaches comprising: an exhaust gas processing part 40 provided on an upstream side of the exhaust gas guide duct, and configured to process the exhaust gas, wherein the recirculation line 80 is connected to the exhaust gas guide duct on a downstream side of the exhaust gas processing part [0017,0020].
Conclusion
Applicant's amendment necessitated the new ground(s) of rejection presented in this Office action. Accordingly, THIS ACTION IS MADE FINAL. See MPEP § 706.07(a). 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 CRAIG SANG KIM whose telephone number is (571)270-1418. The examiner can normally be reached 7:00 AM - 3:00 PM.
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/CRAIG KIM/
Primary Examiner
Art Unit 3741
Prosecution Insights