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 .
Continued Examination Under 37 CFR 1.114
A request for continued examination under 37 CFR 1.114, including the fee set forth in 37 CFR 1.17(e), was filed in this application after final rejection. Since this application is eligible for continued examination under 37 CFR 1.114, and the fee set forth in 37 CFR 1.17(e) has been timely paid, the finality of the previous Office action has been withdrawn pursuant to 37 CFR 1.114. Applicant's submission filed on 3/23/2026 has been entered.
Claim Objections
Claim 1 objected to because of the following informalities: “one or more heat exchangers” in line 6 should read “one or more additional heat exchangers”. Appropriate correction is required.
Claim Rejections - 35 USC § 103
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.
Claims 1, 4, 5, 7-9, and 12-19 are rejected under 35 U.S.C. 103 as being unpatentable over Lear (US-Pub 20190186729) in view of Klingels (DE 2020/000055, US patent 11976580 being used as English equivalent).
Regarding claim 1, Lear discloses a system of suppressing contrails emitted from an aircraft (this represents intended use of the system, the system itself only has to be capable of suppressing contrails from an aircraft, and since the system of Lear can be used to remove water vapor from an exhaust stream, it would perform the claimed function) comprising: a semi-closed cycle gas turbine engine (fig 3) of an aircraft (this is intended use of the turbine engine, meaning that the aircraft does not actually need to be shown, but the turbine could be used in an aircraft) that exhausts gases in use; a recuperator (123, fig 3) component that is positioned within an exhaust gas stream (dashed line leaving 116, fig 3) of the semi-closed cycle gas turbine engine to remove a portion of the exhaust gas stream to heat combustion air (the recuperator takes heat from the exhaust gas and delivers it to the compressed air leaving 113, fig 3); and direct the portion of the exhaust gas stream to one or more additional heat exchangers (133, 136, and 139, fig 3); and the one or more additional heat exchangers in a recirculation path that are configured to heat a secondary fluid to condense the exhaust gas (solid black arrow from 133, fig 3, the exhaust gas is condensed, meaning that the exhaust gas is cooled while the cooling fluid is heated) to remove water vapor from the exhaust gas stream before the portion of the exhaust gas stream is recirculated through the semi-closed cycle gas turbine engine (146, fig 3), wherein the ambient air stream is output from the one or more additional heat exchangers to the fan nozzle of the aircraft to provide thrust to the aircraft.
Lear does not disclose wherein the one or more additional heat exchangers are configured to receive parallel streams flowing in opposite directions, wherein the parallel streams comprise an ambient air stream and the portion of the exhaust gas stream output from the recuperator component, wherein the one or more additional heat exchangers in the recirculation path are configured to heat up the ambient air stream before the ambient air stream exits via a fan nozzle, and then exhausting the ambient airstream without being mixed with an exhaust gas flow.
Klingels teaches a using a water extraction device similar to Lear in an aircraft, wherein a heat exchanger (22, fig 4) is configured to receive parallel streams flowing in opposite directions (air coming from 12 and air coming from 11, fig 4), wherein the parallel streams comprise an ambient air stream ( ambient air comes through the fan section in the same manner as applicants fig 6a) and the portion of the exhaust gas stream output from the upstream heat exchanger (12, fig 4), wherein the one or more additional heat exchangers in the recirculation path are configured to, before the ambient air stream exits via a fan nozzle (as can be seen in 36, fig 5, as it is not shown in fig 4 for simplicity but the fan duct would have an exit nozzle), heat up the ambient air stream, wherein the heated ambient air stream is no mixed with an exhaust fluid stream (exhaust fluid is output through 25, fig 4) before being output from the one or more additional heat exchangers to the fan nozzle of the aircraft to provide thrust to the aircraft (the hot air will add to the mass flow rate of air accelerating as it exits the fan nozzle, thus would provide thrust to the aircraft).
It would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to have modified the exhaust water removal system disclosed by Lear by using a parallel stream of ambient air in order to condense the water from the exhaust gas based on the teaching of Klingels. Doing so would reduce the climate impact of the aircraft (col 2, lines 7-13), as suggested by Klingels.
Regarding claim 4, Lear as modified by Klingels in claim 1 discloses wherein the semi-closed cycle gas turbine engine comprises a turbofan jet implementation of the semi-closed cycle gas turbine engine (10 has a fan 11 making it a turbofan engine, fig 4, Klingels.
Regarding claim 5, Lear discloses wherein the semi-closed cycle gas turbine engine comprises a turbojet implementation of the semi-closed cycle gas turbine engine (a turbojet is an engine that has a compressor 113, fig 3, combustor 119, fig 3, turbine 116, fig 3, and releases exhaust 153, fig 3 to provide thrust, therefore, Lear discloses a turbojet implementation of the engine).
Regarding claim 7, Lear discloses wherein the semi-closed cycle gas turbine engine comprises a high pressure compressor (113, fig 3) , a high pressure turbine (116, fig 3), and a combustor (119, fig 3).
Regarding claim 8, Lear discloses wherein compressed gas from the high pressure compressor is provided to the recuperator component (dotted arrow from 113, fig 3).
Regarding claim 9, Lear discloses a method of removing water from an exhaust comprising: providing a semi-closed cycle gas turbine engine (fig 3) that exhausts gases in use; removing, via a recuperator (123, fig 3) component, a portion of the exhaust gas stream to heat combustion air (recuperators remove heat from exhaust and delivers it to the compressor air flow formed by the dotted line leading from 113); directing the portion of the exhaust gas stream to one or more heat exchangers (133, 136, and 139, fig 3); receiving, via the one or more heat exchangers in a recirculation path (dotted line leading from 123 to 146, fig 3) from the recuperator, the removed exhaust gas stream; condensing the removed exhaust gas stream to form liquid water (cold water, solid black line, fig 3), and recirculating the removed portion of the exhaust gas stream through the semi-closed cycle gas turbine engine (146, fig 3).
Lear does not disclose a method of suppressing contrails emitted from an aircraft, and internally storing the liquid water thereby suppressing a formation of contrails emitted from the aircraft via the exhaust gas stream, wherein the one or more additional heat exchangers are configured to receive parallel streams flowing in opposite directions, wherein the parallel streams comprise an ambient air stream and the portion of the exhaust gas stream output from the recuperator component, wherein the one or more additional heat exchangers in the recirculation path are configured to heat up the ambient air stream before directing the ambient air stream trough an exit fan nozzle of the aircraft, by outputting the ambient air stream from the one or more heat exchangers to the exit fan nozzle of the aircraft to provide thrust to the aircraft
Klingels teaches a method of suppressing contrails emitted from an aircraft (col 2, lines 7-13, the water is recovered from the exhaust gas, contrails are formed by water emitted from the exhaust gas, thus the method of removing water of Klingels would suppress contrails) in a turbine engine similar to that of Lear, wherein a heat exchanger (22, fig 4) is configured to receive parallel streams flowing in opposite directions (air coming from fan 11 and exhaust coming from HX 12, fig 4), wherein the parallel streams comprise an ambient air stream (air coming from fan 11, fig 4) and the portion of the exhaust gas stream (stream from 12, fig 4) output from the heat exchanger upstream (12, fig 4), wherein the one or more additional heat exchangers in the recirculation path are configured to heat up the ambient air stream, and internally storing the liquid water condensed (28, fig 4 is an accumulator) thereby suppressing a formation of contrails emitted from the aircraft via the exhaust gas stream, and direct the ambient air stream through an exit fan nozzle of the aircraft (although not shown for simplicity, the fan duct would have an exit similar to 36, fig 5), by outputting the ambient air stream from the one or more heat exchangers the exit fan nozzle of the aircraft, wherein the heated ambient airstream is not mixed with an exhaust fluid stream (21, fig 4) before being output to the fan nozzle to provide thrust to the aircraft (the hot air will add to the mass flow rate of air accelerating as it exits the fan nozzle, thus would provide thrust to the aircraft).
It would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to have modified the exhaust water removal system disclosed by Lear by using an exhaust water removal system in an aircraft by using parallel airstreams of recuperated exhaust and ambient air, and storing the water condensed from the recuperated exhaust thereby suppressing a formation of contrails based on the teachings of Klingels. Doing so would reduce the climate impact of the aircraft (col 2, lines 7-13), as suggested by Klingels.
Regarding claim 12, Lear as modified by Klingels in claim 9 discloses wherein the semi-closed cycle gas turbine engine comprises a turbofan jet implementation of the semi-closed cycle gas turbine engine (10 is a turbofan due to its fan 11, fig 4, Klingels).
Regarding claim 13, Lear discloses wherein the semi-closed cycle gas turbine engine comprises a turbojet implementation of the semi-closed cycle gas turbine engine (a turbojet is an engine that has a compressor 113, fig 3, combustor 119, fig 3, turbine 116, fig 3, and releases exhaust 153, fig 3 to provide thrust, therefore, Lear discloses a turbojet implementation of the engine).
Regarding claim 14, Lear discloses wherein the semi-closed cycle gas turbine engine comprises a high pressure compressor (113, fig 3) , a high pressure turbine (116, fig 3), and a combustor (119, fig 3).
Regarding claim 15, Lear discloses directing compressed gas from the high pressure compressor is provided to the recuperator component (dotted arrow from 113, fig 3).
Regarding claims 16 and 17, Lear as modified by Klingels further discloses the aircraft (3, fig 6).
Regarding claim 18, Lear discloses a saturator component (303, fig 3) in fluidic communication with the high pressure compressor, the one or more additional heat exchangers, and the recuperator component, wherein input flows to the saturator component comprises fluidic flows from the high pressure compressor and the one or more heat exchangers, wherein an output flow of the saturator component is received by the recuperator component (123, fig 3).
Regarding claim 19, Lear discloses wherein the semi-closed cycle gas turbine engine further comprises a saturator component (303, fig 3) in fluidic communication with the high pressure compressor, the one or more additional heat exchangers, and the recuperator component, the method further comprising: directing fluidic flows from the high pressure compressor and the one or more heat exchangers to the saturator component (inlets from 136 and 113, fig 3); and directing an output flow of the saturator component to the recuperator component (123, fig 3).
Claims 2 and 3 are rejected under 35 U.S.C. 103 as being unpatentable over Lear as modified by Klingels in claim 1, further in view of Haugstetter (10773819).
Regarding claims 2 and 3, Lear does not disclose a storage tank for internally storing liquid water formed from the removed water vapor, wherein the storage tank comprises a fuel tank of the aircraft having a bladder that separates the liquid water from a fuel source for aircraft.
Haugstetter teaches a storage tank (13, fig 4) for an aircraft (10, fig 1) for internally storing liquid water formed from the removed water vapor (12, fig 4), wherein the storage tank comprises a fuel tank (13, fig 4) of the aircraft having a bladder (14, fig 4) that separates the liquid water from a fuel source for aircraft (the liquid inside 13 is fuel).
It would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to have modified the system for using water disclosed by Lear as modified by Klingels by having a water storage system comprising a fuel tank having a bladder that separates the water and fuel based on the teachings of Haugstetter. Doing so would allow for water generated during a flight to be stored for later without needing a dedicated storage space (col 1, lines 15-30), as suggested by Haugstetter.
Claim 6 is rejected under 35 U.S.C. 103 as being unpatentable over Lear as modified by Klingels in claim 1, further in view of Hoffjann (8640439).
Regarding claim 6, Lear as modified by Klingels does not disclose wherein the semi-closed cycle gas turbine engine is part of an electrical propulsion system for the aircraft.
Hoffjann teaches using a gas turbine engine (2, fig 2) as part of an electrical propulsion (the electric motor 3 uses the gas turbine engine shaft 7 as a means to drive the propulsor 1, fig 2) system for an aircraft.
It would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to have modified the gas turbine engine disclosed by Lear as modified by Klingels by using the gas turbine as part of an electrical propulsion system based on the teachings of Hoffjann. Using a mixed drive system can reduce generated pollutants (col 1, lines 25-30), as suggested by Hoffjann
Claim 10 is rejected under 35 U.S.C. 103 as being unpatentable over Lear as modified by Klingels as applied to claim 9 above, and further in view of Hoffjann.
Regarding claim 10, Lear as modified by Klingels does not disclose utilizing the stored liquid water as sanitation water for the aircraft.
Hoffjann teaches wherein water on an aircraft used for injection into a combustor can also be used as sanitation water (col 4, lines 15-30).
It would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to have modified the water usage disclosed by Lear as modified by Klingels by using the produced water as sanitation water based on the teachings of Hoffjann. Doing so would reduce the amount of water which is carried along (col 4, lines 23-27), as suggested by Hoffjann.
Claim 11 is rejected under 35 U.S.C. 103 as being unpatentable over Lear as modified by Klingels as applied to claim 9 above, and further in view of Haugstetter.
Regarding claim 11, Lear as modified by Klingels does not disclose wherein the liquid water is stored in a fuel tank having a bladder separating the liquid water from a fuel source for the aircraft.
Haugstetter teaches a storage tank (13, fig 4) for an aircraft (10, fig 1) for internally storing liquid water formed from removed water vapor (12, fig 4), wherein the storage tank comprises a fuel tank (13, fig 4) of the aircraft having a bladder (14, fig 4) that separates the liquid water from a fuel source for aircraft (the liquid inside 13 is fuel).
It would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to have modified the system for using water disclosed by Lear as modified by Klingels by having a water storage system comprising a fuel tank having a bladder that separates the water and fuel based on the teachings of Haugstetter. Doing so would allow for water generated during a flight to be stored for later without needing a dedicated storage space (col 1, lines 15-30), as suggested by Haugstetter.
Response to Arguments
Applicant's arguments filed 3/23/2026 have been fully considered but they are not persuasive. Applicant argues that Lear does not disclose the exhaust gas stream output from the recuperator component. This argument is not persuasive, because as set forth in the rejection above, its not the exhaust gas stream that Lear doesn’t disclose, as it is set forth in the rejection under Lear, it’s the exhaust gas stream being a parallel stream with the ambient airstream. Applicant argues that Lear and Klingels does not disclose the newly added limitations, this argument is not persuasive as per the rejection above. Applicant further argues that the claimed subject matter would require a substantial reconstruction of Klingels, however, this argument is not persuasive, as the modification being made is using the gas turbine engine of Lear in an aircraft such as Klingels, and the modifications needed to make that transfer would be well understood to one of ordinary skill in the art as stationary power plants and aircraft power plants are the two main use cases for gas turbine engines. Lastly, applicant argues that the design of Klingels functions differently and would reduce thrust, and the recuperator and saturator of applicants disclosure exists simultaneously. These arguments are not persuasive because Klingels would not necessarily reduce thrust, since the mass flow from the water is being recirculated to the combustor to allow a greater power output, and even if it were, there are still other advantages of condensing the water such as environmental and power efficiency which one of ordinary skill in the art would find useful based on design requirements. And regarding the argument that the recuperator and saturator both exist, this argument is moot as Lear is being used to teach the saturator and Klingels also has both simultaneously.
Conclusion
Any inquiry concerning this communication or earlier communications from the examiner should be directed to SEAN V MEILLER whose telephone number is (571)272-9229. The examiner can normally be reached 7am-5pm.
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/SEAN V MEILLER/Examiner, Art Unit 3741
/DEVON C KRAMER/Supervisory Patent Examiner, Art Unit 3741
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