DETAILED ACTION
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 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.
Claim Rejections - 35 USC § 112
The following is a quotation of 35 U.S.C. 112(b):
(b) CONCLUSION.—The specification shall conclude with one or more claims particularly pointing out and distinctly claiming the subject matter which the inventor or a joint inventor regards as the invention.
The following is a quotation of 35 U.S.C. 112 (pre-AIA ), second paragraph:
The specification shall conclude with one or more claims particularly pointing out and distinctly claiming the subject matter which the applicant regards as his invention.
Claims 1-3, 5-8, 10-16, 18-20 are rejected under 35 U.S.C. 112(b) or 35 U.S.C. 112 (pre-AIA ), second paragraph, as being indefinite for failing to particularly point out and distinctly claim the subject matter which the inventor or a joint inventor, or for pre-AIA the applicant regards as the invention.
Regarding claims 1 and 13, “a plurality of condenser pairs…in flow communication with a corresponding one of the plurality of turning portions” is unclear whether each pair corresponds to one turning portion, or whether all the pairs share one of the turning portions.
Regarding claim 1, the recitation “inner faces transverse to both the forward face and the inner face” is unclear because it recites inner faces transverse to themselves.
Regarding claim 10, “a power turbine coupled to drive the propulsor, the power turbine….is not mechanically coupled to the core engine” renders the claim indefinite because claim 1 recites the “propulsor driven…by the core engine”. Thus it is unclear whether there are two different embodiments being claimed, or whether the core engine is driving the propulsor without mechanically coupling to the power turbine, which also drives the propulsor.
Regarding claim 19, “wherein core engine”, “a turbine section”, “a combustor”, and “of compressor section” are unclear as to whether they are the same as, or different from, corresponding structures that are previously claimed in claim 19.
Furthermore, various recitations of plural objects and corresponding one or more other objects are not consistent and unclear as to whether there is respective one-to-one correspondence, or whether some objects share a single one of the other objects. For example, “the turning portions are configured to turn the exhaust gas flow axially aft toward a corresponding one of a plurality of condenser pairs” us unclear whether the plural turning portions share a single condenser pair, or whether there is a one-to-one relationship between condenser pairs and turning portions.
Dependent Claims 2-3, 5-8, 10-12, 14-16, 18, and 20 are also rejected for relying on at least one rejected claim above.
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.
Claims 13-16 and 18 is/are rejected under 35 U.S.C. 103 as being unpatentable over Sibbach 12221905 in view of Jancel FR688634A and Klingels 20230286661.
Regarding claim 13, Sibbach teaches a water recovery system (100) for an aircraft propulsion system (Figs 1-2) comprising:
a condenser (incl. 104) where water is condensed from an exhaust gas flow (66),
wherein the condenser receives a cooling airflow from a bypass duct (62); and
a water separator (106) where the water from the condenser is separated from the exhaust gas flow (Fig 2);
a nacelle (50) where the plurality of condenser pairs and the plurality of water separators are supported (Figs 1-2; condensers and water separators are coupled to the nacelle either directly or indirectly), the nacelle comprises a cooling air duct assembly (to pass air 62) where a portion of inlet airflow (62 of 58) is communicated to the condenser for providing the cooling airflow (62) through the condenser (Figs 1-2A);
an evaporator (102) corresponding to the condenser (Fig 2A) and
an exhaust duct assembly (incl. outlet of 30, steam system 100, 76) comprising a plurality of strut portions that extend radially outward from a common center portion (at 102) to a condenser (104; Fig 1; steam system 100 extending axisymmetrically about the axis requires at least two structures – at top and bottom - extending radially to support the central portion relative to the nacelle; definition of strut per Merriam Webster: “a structural piece designed to resist pressure in the direction of its length”, such structural piece may be interpreted to comprise multiple parts),
wherein the common center portion is configured to turn the exhaust gas flow radially outward through the strut portions, the exhaust gas flow then turning axially aft (Fig 2);
the condenser (104) receiving exhaust gas flow (from boiler 102) and a cooling airflow (62), and exhausting each of these after heat exchange (Fig 2; col.8 ll.42-52).
Sibbach further teaches the condenser is a heat exchanger (col.8 ll.42-52) that is part of a steam system (100; Figs 1-2) that facilitates increased bypass ratio and thermal efficiency (col.2 l.54 – col.3 l.28), and the exhaust flow flows radially outward to the condenser before flowing axially aftward (Figs 1-2).
Sibbach does not teach a plurality of turning portions to which the radial struts extend and conduct exhaust gas flow thereto; the condenser comprising a plurality of condenser pairs circumferentially spaced about a propulsor axis, wherein each of the condenser pairs comprise inner faces for receiving the cooling airflow that taper inward from an open forward portion toward a closed aft portion such that the cooling airflow flows through the inner faces toward outward faces; a plurality of the water separator; a plurality of the evaporator, and the plurality of the turning portions that are configured to turn the exhaust gas toward a corresponding one of the plurality of condenser pairs; wherein each condenser of the condenser pair comprises a forward face for receiving the exhaust gas flow from the exhaust duct assembly, an aft face for exhausting exhaust gas flow, and the inner faces being transverse to both the forward face and the aft face.
However, Jancel teaches a heat exchanger for all liquids and fluids (Title) in aerospace application (Col.1 l.20) wherein the heat exchanger comprises at least one heat exchanger (HX) pair (Fig 10) wherein the HX pair comprises inner faces (IF in Fig 10 below) for receiving a cooling airflow (analogous to airflow A in Fig 1) that taper inward from an open forward portion (at C) toward a closed aft portion (C’; p.3 col.1 l.48 – col.2 l.12, e.g. pleated sheet metal T option shown in Fig 11) such that the cooling airflow flows through the inner faces toward outward faces (A flows through B analogous to the flow of arrows A in Fig 1); the heat exchanger further comprising a turning portion (at C) that is configured to receive a hot fluid flow (at O) and turn the flow axially aft relative to the cooling airflow (shared feature in Figs 1, 10) toward the corresponding condenser pair (heat exchange portion B);
wherein each HX of the HX pair comprises a forward face (where B receives fluid from C and/or where B’ receives fluid from C’) for receiving a first relative hot fluid (from O), and an aft face (where B ejects fluid into C’ and/or where B’ ejects fluid into C) for exhausting the first fluid, wherein the inner faces (IF in Fig 10 below) are transverse to both the forward face and the aft face (Fig 10).
PNG
media_image1.png
346
346
media_image1.png
Greyscale
It would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to modify the condenser heat exchanger of Sibbach to comprise at least one inclined heat exchanger pair as taught by Jancel in order to provide a heat exchanger that channels and compresses the cooling airflow through the heat exchanger in an adjustable manner, thus mitigating aircraft resistance to forward movement (which increases its aerodynamic qualities), improving heat exchanger efficiency (Jancel, p.1 col.1 l.17 – col.2 l.13), and providing the option of modulating cooling capacity (Jancel, p.3 col.1 ll.5-47).
Sibbach in view of Jancel still does not teach a plurality of the condenser heat exchangers circumferentially spaced apart about the propulsor axis, a plurality of the water separator, and a plurality of the evaporator.
However, Klingels teaches the use of multiple condenser heat exchangers (32) distributed circumferentially about a propulsor axis (Figs 1-2) for exchanging heat between core turbine exhaust (from 18) and bypass duct cooling air (flowing in 37; Figs 1-2); using a plurality of separators (42) in the water separator channel (200) to separate water from the condensed exhaust gas of a turbofan engine (Note that the plurality of water separators, together, receive all the exhaust gas from the all the condensers of the engine system), and a plurality of evaporators (Fig 1 above).
PNG
media_image2.png
648
888
media_image2.png
Greyscale
It would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to modify the single condenser, single water separator, and single evaporator of Sibbach in view of Jancel to be multiple condensers and water separators as taught by Klingels because MPEP 2144.04(VI)(B) provides that mere duplication of essential working parts of a device for amplified effect is an obvious extension of prior art teachings, In re Harza, 274 F.2d 669, 124 USPQ 378 (CCPA 1960), MPEP 2144.04 VI B, the amplified effect being increased cooling capacity and water separation.
Regarding claim 14, Sibbach in view of Jancel and Klingels teaches all the limitations of the claimed invention as discussed above (including a plurality of the water separator). Sibbach further teaches the plurality of evaporators are part of an evaporator system (incl. 102) where the water from the water separator is transformed into a steam flow (176) and communicated to a combustor (26).
Regarding claim 15, Sibbach in view of Jancel and Klingels teaches all the limitations of the claimed invention as discussed above (including a plurality of the water separator and a plurality of evaporators). Sibbach further teaches the evaporator corresponding to the condenser (evaporator feeds exhaust gas flow to condenser; Fig 2).
Regarding claim 16, Sibbach in view of Jancel and Klingels teaches all the limitations of the claimed invention as discussed above.
Sibbach in view of Jancel and Klingels as discussed so far, does not teach each of the plurality of condenser pairs comprises an outer condenser disposed radially outward of an inner condenser and the inward faces face inward toward each other and the outward faces face outward relative to each other.
However, Jancel further teaches each of the plurality of condenser pairs comprises an outer condenser (B) disposed above/vertically on top of an inner condenser (B’; Fig 10) and the inward faces face inward toward each other and the outward faces face outward relative to each other (Fig 10).
Applying the geometry of Jancel’s condenser pair to the condensers of Sibbach in view of Jancel and Klingels, results in the claimed orientation where the radial direction is analogous to the vertical direction.
It would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to modify the condenser heat exchangers of Sibbach in view of Jancel and Klingels to comprise the heat exchanger pair geometry as taught by Jancel in order to provide a heat exchanger that channels and compresses the cooling airflow through the heat exchanger in an adjustable manner, thus mitigating aircraft resistance to forward movement (which increases its aerodynamic qualities), improving heat exchanger efficiency (Jancel, p.1 col.1 l.17 – col.2 l.13), and providing the option of modulating cooling capacity (Jancel, p.3 col.1 ll.5-47).
Regarding claim 18, Sibbach in view of Jancel and Klingels teaches all the limitations of the claimed invention as discussed above (including the plurality of condenser pairs). Sibbach further teaches the nacelle comprises a bypass air duct assembly (incl. at least an upstream portion of 56 and 76) where another portion of the inlet airflow is bypassed (56 provides a duct for air 62 to bypass a core engine 16, and flow “over or through” the condenser, col.10 ll.58-63) around the condenser and a core engine (16; Figs 1-2).
Additionally, Klingels teaches passing only a portion of the inlet airflow through the condensers as cooling airflow, with the remainder flowing past/over the condensers as bypass air to bypass nozzle for thrust generation ([0091]); this arrangement being substitutionally equivalent to arrangements where all the inlet airflow in the bypass duct passes through the condenser to the bypass nozzle ([0091]).
It would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to modify Sibbach in view of Jancel and Klingels to pass at least a portion of inlet airflow around the condensers as taught by Klingels and Sibbach, because passing all or some of the inlet air through the condenser was considered substitutionally equivalent by Klingels ([0091]). See MPEP2144.06(II).
Claims 1-3, 5, 7-8, 10-11, and 19-20 is/are rejected under 35 U.S.C. 103 as being unpatentable over Suciu 9989011 in view of Sibbach 12221905 in view of Jancel FR688634A and Klingels 20230286661.
Regarding Claim 1, Suciu teaches an aircraft propulsion system (Fig 1) comprising:
a core engine (36) comprising a compressor (38), combustor (42), and turbine section (40),
wherein an inlet airflow (into 24) is compressed (by at least 38), communicated to the combustor (Fig 1), mixed with fuel (by definition of combustor), and ignited to generate (by definition of combustor) an exhaust gas flow (into 40) that is expanded through the turbine section (Fig 1),
wherein the turbine section is engine forward of the combustor and the compressor (Fig 1), and
an inlet duct assembly (incl. 300) communicates a portion of the inlet airflow to an inlet (at upstream end of 38) that is disposed aft of the compressor section (Fig 1);
a propulsor (24) driven about a propulsor axis (Y) by the core engine (core engine provides high energy fluid to drive the power turbine 46, which drives the propulsor 24); and
an exhaust duct assembly (structures downstream of 40) comprising a plurality of radial struts (15) that extend radially between a common center portion (Fig 2 below) and a corresponding one of a plurality of turning portions (where 15 meets 32),
PNG
media_image3.png
435
766
media_image3.png
Greyscale
wherein the common center portion directs exhaust gas flow from the turbine section radially outward through a corresponding one of the plurality of radial struts and into a corresponding one of the plurality of the plurality of the turning portions (i.e. via duct 48 extending from center portion, through a radial strut, and turning axial aft upon exiting the strut into 32; Fig 1), the exhaust gas flow flowing axially forward from the turbine section, then radially outward, and axially aftward (Fig 1).
Suciu does not teach a plurality of condenser pairs circumferentially spaced apart about the propulsor axis and in flow communication with a corresponding one of the plurality of turning portions of the exhaust duct assembly, wherein each condenser of the condenser pair comprises a forward face for receiving the exhaust gas flow from the exhaust duct assembly, an aft face for exhausting exhaust gas flow, and inner faces transverse to both the forward face and the inner face (interpreted under 112b to be the aft face), the inner faces are configured for receiving a cooling airflow and taper inward from an open forward portion toward a closed aft portion such that the cooling airflow flows through the inner faces toward outward faces.
However, Sibbach teaches an aircraft propulsion system (Figs 1-2) comprising:
a core engine (16 incl. 21, 22, 24, 26, 27, 28, 30) comprising a compressor (21,22, 24), combustor (26), and turbine section (27, 28, 30), wherein an inlet airflow (58, 64) is compressed communicated to the combustor, mixed with fuel (84), and ignited to generate an exhaust gas flow (66) that is expanded through the turbine section (Figs 1-2);
a propulsor (14) driven about a propulsor axis (12) by the core engine (Figs 1-2);
an exhaust duct assembly (incl. outlet of 30, steam system 100, 76) comprising a plurality of radial strut portions that extend radially outward between a common center portion (at 102; Fig 1; steam system 100 extending axisymmetrically about the axis requires at least two structures – at top and bottom - extending radially to support the central portion relative to the nacelle; definition of strut per Merriam Webster: “a structural piece designed to resist pressure in the direction of its length”, such structural piece may be interpreted to comprise multiple parts) and a corresponding one of a plurality of turning portions that correspond to each of the plurality of strut portions (where radial strut meets duct wall 50),
wherein the common center portion directs exhaust gas flow from the turbine section radially outward through a corresponding one of the plurality of radial struts and into a corresponding one of the plurality of the turning portions (Fig 2; following arrows 66, 170);
a condenser (104) in flow communication with a corresponding one of the plurality of turning portions of the exhaust duct assembly (Fig 2), wherein the condenser receives exhaust gas flow (from boiler 102) and a cooling airflow (62), and exhausts each of these after heat exchange (Fig 2; col.8 ll.42-52).
Sibbach further teaches the condenser is a heat exchanger (col.8 ll.42-52) that is part of a steam system (100; Figs 1-2) that facilitates increased bypass ratio and thermal efficiency (col.2 l.54 – col.3 l.28), and the exhaust flow flows radially outward to the condenser before flowing axially aftward (Figs 1-2).
It would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to modify the engine of Suciu to include the condenser and steam system of Sibbach in order to facilitate increased bypass ratio and thermal efficiency (Sibbach, col.2 l.54 – col.3 l.28).
Suciu in view of Sibbach does not teach the condenser is a plurality of condenser pairs circumferentially spaced apart about the propulsor axis, wherein each condenser of the condenser pair comprises a forward face for receiving the exhaust gas flow from the exhaust duct assembly, an aft face for exhausting exhaust gas flow, and inner faces transverse to both the forward face and the inner face (interpreted under 112b to be the aft face), the inner faces are configured for receiving a cooling airflow and taper inward from an open forward portion toward a closed aft portion such that the cooling airflow flows through the inner faces toward outward faces.
However, Jancel FR688634A teaches a heat exchanger for all liquids and fluids (Title) in aerospace application (Col.1 l.20) wherein the heat exchanger comprises at least one heat exchanger (HX) pair (Fig 10) wherein each HX of the HX pair comprises a forward face (where B receives fluid from C and/or where B’ receives fluid from C’) for receiving a first relative hot fluid (from O), an aft face (where B ejects fluid into C’ and/or where B’ ejects fluid into C) for exhausting the first fluid, and inner faces (IF in Fig 10 below) transverse to both the forward face and the aft face (Fig 10), the inner faces being configured for receiving a cooling airflow (analogous to airflow A in Fig 1) and taper inward from an open forward portion (at C) toward a closed aft portion (C’; p.3 col.1 l.48 – col.2 l.12, e.g. pleated sheet metal T option shown in Fig 11) such that the cooling airflow flows through the inner faces toward outward faces (A flows through B analogous to the flow of arrows A in Fig 1).
PNG
media_image1.png
346
346
media_image1.png
Greyscale
It would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to modify the condenser heat exchanger of Sibbach to comprise at least one inclined heat exchanger pair as taught by Jancel in order to provide a heat exchanger that channels and compresses the cooling airflow through the heat exchanger in an adjustable manner, thus mitigating aircraft resistance to forward movement (which increases its aerodynamic qualities), improving heat exchanger efficiency (Jancel, p.1 col.1 l.17 – col.2 l.13), and providing the option of modulating cooling capacity (Jancel, p.3 col.1 ll.5-47).
Sibbach in view of Jancel still does not teach a plurality of the condenser heat exchangers spaced apart about the propulsor axis.
However, Klingels teaches the use of multiple condenser heat exchangers (32) distributed circumferentially about a propulsor axis (Figs 1-2) for exchanging heat between core turbine exhaust (from 18) and bypass duct cooling air (flowing in 37; Figs 1-2).
It would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to modify the single condenser of Sibbach in view of Jancel to be multiple condensers as taught by Klingels because MPEP 2144.04(VI)(B) provides that mere duplication of essential working parts of a device for amplified effect is an obvious extension of prior art teachings, In re Harza, 274 F.2d 669, 124 USPQ 378 (CCPA 1960), MPEP 2144.04 VI B, the amplified effect being increased cooling capacity.
Regarding claim 2, Suciu in view of Sibbach, Jancel, and Klingels teaches all the limitations of the claimed invention as discussed above (including there being a plurality of condenser pairs).
Suciu in view of Sibbach, Jancel, and Klingels as discussed so far, does not teach a plurality of water separators where water from corresponding ones of the plurality of condenser pairs is separated from the exhaust gas flow.
However, Sibbach further teaches a water separator (106) is part of the steam system (100), where water from the condenser is separated from the exhaust gas flow (Fig 2).
And, Klingels further teaches using a plurality of separators (42) in the water separator channel (200) to separate water from the condensed exhaust gas of a turbofan engine. Note that the plurality of water separators, together, receive all the exhaust gas from the all the condensers of the engine system.
It would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to modify the system of Suciu in view of Sibbach, Jancel, and Klingels to use multiple water separators as taught by Sibbach and Klingels in order to facilitate increased bypass ratio and thermal efficiency (Sibbach, col.2 l.54 – col.3 l.28), and because MPEP 2144.04(VI)(B) provides that mere duplication of essential working parts of a device for amplified effect is an obvious extension of prior art teachings, In re Harza, 274 F.2d 669, 124 USPQ 378 (CCPA 1960), MPEP 2144.04 VI B, the amplified effect being increased water separation.
Regarding claim 3, Suciu in view of Sibbach, Jancel, and Klingels teaches all the limitations of the claimed invention as discussed above. Suciu in view of Sibbach, Jancel, and Klingels as discussed so far, does not teach an evaporator system where water extracted from the exhaust gas flow is heated to generate a steam flow for injection into the core engine.
However, Sibbach further teaches an evaporator system (102) where water extracted from the exhaust gas flow (via 104, 106, 107, 108) is heated to generate a steam flow (176) for injection into the core engine (at 26).
It would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to modify the system of Suciu in view of Sibbach, Jancel, and Klingels to use the steam system of Sibbach in order to facilitate increased bypass ratio and thermal efficiency (Sibbach, col.2 l.54 – col.3 l.28).
Regarding claim 5, Suciu in view of Sibbach, Jancel, and Klingels teaches all the limitations of the claimed invention as discussed above. Suciu in view of Sibbach, Jancel, and Klingels as discussed so far, does not teach the evaporator system further comprises a plurality of evaporators disposed within the center portion of the exhaust duct assembly.
However, Sibbach further teaches the evaporator (102) is disposed within the center portion of the exhaust duct assembly (Figs 1-2).
And, Klingels teaches using a plurality of evaporators (30 comprising multiple heat exchangers; [0085]) within the central portion of an exhaust duct assembly (Fig 1) to generate steam using heat from the core turbine exhaust and feedwater condensed from the exhaust (Fig 1).
It would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to modify the system of Suciu in view of Sibbach, Jancel, and Klingels to include multiple evaporators as taught by Sibbach and Klingels, in order facilitate increased bypass ratio and thermal efficiency (Sibbach, col.2 l.54 – col.3 l.28), and because MPEP 2144.04(VI)(B) provides that mere duplication of essential working parts of a device for amplified effect is an obvious extension of prior art teachings, In re Harza, 274 F.2d 669, 124 USPQ 378 (CCPA 1960), MPEP 2144.04 VI B, the amplified effect being enhanced steam heating.
Regarding claim 7, Suciu in view of Sibbach, Jancel, and Klingels teaches all the limitations of the claimed invention as discussed above (including there being a plurality of condenser pairs).
Suciu further teaches inlet airflow is communicated to/past the exhaust duct assembly (via 32; Figs 1-2A) to bypass nozzle (17).
Suciu in view of Sibbach, Jancel, and Klingels as discussed so far, does not teach a cooling air duct assembly where a portion of the inlet airflow is communicated to each of the plurality of condenser pairs.
However, Sibbach further teaches a cooling air duct assembly (incl. at least a downstream portion of 56 and cooling air passage(s) through 104) where a portion of inlet airflow (62) is communicated to the condenser (Figs 1-2) at the exhaust duct assembly.
It would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to modify the system of Suciu in view of Sibbach, Jancel, and Klingels to the steam system taught by Sibbach in order to facilitate increased bypass ratio and thermal efficiency (Sibbach, col.2 l.54 – col.3 l.28).
Regarding claim 8, Suciu in view of Sibbach, Jancel, and Klingels teaches all the limitations of the claimed invention as discussed above (including there being a plurality of condenser pairs).
Suciu in view of Sibbach, Jancel, and Klingels as discussed so far, does not teach a bypass air duct assembly where another portion of the inlet airflow is bypassed around the plurality of condenser pairs and the core engine.
However, Sibbach further teaches a bypass air duct assembly (incl. at least an upstream portion of 56 and 76) where a portion of the inlet airflow is bypassed around the condenser and the core engine (56 provides a duct for air 62 to bypass the core engine, and flow “over or through” the condenser, col.10 ll.58-63) at the exhaust duct assembly.
Additionally, Klingels teaches passing only a portion of the inlet airflow through the condensers as cooling airflow, with the remainder flowing past/over the condensers (32) and an exhaust duct assembly (downstream of turbine19) as bypass air to bypass nozzle (36) for thrust generation ([0091]); this arrangement being substitutionally equivalent to arrangements where all the inlet airflow in the bypass duct passes through the condenser to the bypass nozzle ([0091]).
It would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to modify Suciu in view of Sibbach, Jancel, and Klingels to pass at least a portion of inlet airflow around the condensers as taught by Klingels and Sibbach, in order to facilitate increased bypass ratio and thermal efficiency (Sibbach, col.2 l.54 – col.3 l.28), and because passing all or some of the inlet air through the condenser was considered substitutionally equivalent by Klingels ([0091]). See MPEP2144.06(II).
Regarding claim 10, Suciu in view of Sibbach, Jancel, and Klingels teaches all the limitations of the claimed invention as discussed above. Suciu further teaches a power turbine (46) driven by the exhaust gas flow from the core engine and coupled to drive the propulsor (via 26), the power turbine disposed engine forward of the core engine (Fig 1) and is not mechanically coupled to the core engine (Fig 1).
Regarding claim 11, Suciu in view of Sibbach, Jancel, and Klingels teaches all the limitations of the claimed invention as discussed above (including the condenser comprising a plurality of condenser pairs). Suciu further teaches a nacelle assembly (disposed about 32, Figs 1, 4) disposed about the propulsor and the core engine (Figs 1, 4), wherein the exhaust duct assembly, struts (15), and bypass nozzle (17) are supported within the nacelle assembly (radially inward of nacelle; Figs 1, 4).
Suciu in view of Sibbach, Jancel, and Klingels as discussed so far, does not teach each of the plurality of condenser pairs being supported within the nacelle assembly.
However, Sibbach further teaches the condenser (104, strut/steam system 100) and bypass nozzle (76) being supported within a nacelle assembly (radially inward of 50) disposed about the propulsor and the core engine (Fig 2-3).
It would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to modify Suciu in view of Sibbach, Jancel, and Klingels to use the steam system arrangement of Sibbach, in order to facilitate increased bypass ratio and thermal efficiency (Sibbach, col.2 l.54 – col.3 l.28).
Regarding claim 19, Suciu teaches a method of operating an aircraft propulsion system (Fig 1) comprising:
generating an exhaust gas flow (exiting from 42 into 40) with a core engine (36) comprising a compressor (38), combustor (42), and turbine section (40),
wherein core engine (interpreted under 112b to be the same core engine as above, the subsequently recited turbine, combustor, and compressor being the same as those recited above for the above recited core) comprises a turbine section (40) that is engine forward of a combustor (42) and compressor (38) and
generating the exhaust gas flow comprises communicating a portion of an inlet airflow (into 24) to an inlet (at aft end of compressor 38) disposed aft of compressor section (Fig 1);
coupling a propulsor (24) to a power turbine (46) configured to be driven by expansion of the exhaust gas flow generated by the core engine (exhaust gas flows from 42 to 40 to 46 to 48),
wherein the power turbine and the propulsor are both rotatable about a propulsor axis (Y);
communicating the exhaust gas flow from the power turbine into an exhaust duct assembly (everything downstream of 46) comprising
a plurality of strut portions (15) that extend radially outward from a common center portion (Fig 2 below) to a corresponding one of a plurality of turning portions that correspond to each of the plurality of strut portions (where 15 meets 32),
PNG
media_image3.png
435
766
media_image3.png
Greyscale
wherein the common center portion turns the exhaust gas flow radially outward through the strut portions and into the corresponding one of the plurality of turning portions (i.e. via duct 48 extending from center portion, through a radial strut, and turning axial aft upon exiting the strut into 32; Fig 1),
the exhaust gas flow flowing axially forward from the turbine section, then radially outward, and axially aftward (Fig 1).
Suciu does not teach the turning portions are configured to turn the exhaust gas flow axially aft toward a corresponding one of a plurality of condenser pairs; communicating the exhaust gas flow from the plurality of turning portions of the exhaust duct assembly into a corresponding one of a plurality of condenser pairs circumferentially spaced apart about a propulsor axis, wherein each condenser of the condenser pair comprises a forward face for receiving the exhaust gas flow from the exhaust duct assembly and an aft face for exhausting exhaust gas flow; condensing water in the plurality of condensers pairs wherein each of the condenser pairs comprise inner faces for receiving a cooling airflow that taper inward from an open forward portion toward a closed aft portion such that the cooling airflow flows through the inner faces towards the outward faces; and separating water from the exhaust gas flow in one of a plurality of water separators.
However, Sibbach teaches a method of operating an aircraft propulsion system (Figs 1-2) comprising:
generating an exhaust gas flow (66) with a core engine (16) comprising a compressor (24), combustor (26), and turbine section (28);
coupling a propulsor (14) to a power turbine (30) configured to be driven by expansion of the exhaust gas flow generated by the core engine (Figs 1-2), wherein the power turbine and the propulsor are both rotatable about a propulsor axis (12);
condensing water in a condenser (104) receiving a cooling airflow from a bypass duct (62) and the exhaust gas flow from the engine (Fig 2), the condenser also exhausting these flows (Fig 2); and
separating water from the exhaust gas flow in a water separator (106).
Sibbach further teaches the condenser is a heat exchanger (col.8 ll.42-52) that is part of a steam system (100; Figs 1-2) that facilitates increased bypass ratio and thermal efficiency (col.2 l.54 – col.3 l.28), and the exhaust flow flows radially outward to the condenser before flowing axially aftward (Figs 1-2).
It would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to modify the engine of Suciu to include the condenser and steam system of Sibbach in order to facilitate increased bypass ratio and thermal efficiency (Sibbach, col.2 l.54 – col.3 l.28).
Suciu in view of Sibbach does not teach the turning portions are configured to turn the exhaust gas flow axially aft toward a corresponding one of a plurality of condenser pairs; communicating the exhaust gas flow from the plurality of turning portions of the exhaust duct assembly into a corresponding one of a plurality of condenser pairs circumferentially spaced apart about a propulsor axis, wherein each condenser of the condenser pair comprises a forward face for receiving the exhaust gas flow from the exhaust duct assembly and an aft face for exhausting exhaust gas flow; wherein each of the condenser pairs comprise inner faces for receiving a cooling airflow that taper inward from an open forward portion toward a closed aft portion such that the cooling airflow flows through the inner faces towards the outward faces.
However, Jancel teaches a heat exchanger for all liquids and fluids (Title) in aerospace application (Col.1 l.20) wherein the heat exchanger comprises at least one heat exchanger (HX) pair (Fig 10) wherein the HX pair comprises a turning portion (at C) that is configured to receive a first hot fluid flow (at O) and turn the flow axially aft relative to the cooling airflow (shared feature in Figs 1, 10) toward the corresponding condenser pair (heat exchange portion B);
wherein each condenser (B, B’) of the condenser pair comprises a forward face (where B receives fluid from C and/or where B’ receives fluid from C’) for receiving the first fluid flow and an aft face (where B ejects flow into C’ and/or where B’ ejects fluid flow into C) for exhausting the first fluid flow;
wherein each of the condenser pairs comprise inner faces (IF) for receiving a cooling airflow (analogous to flow A in Fig 1) that taper inward from an open forward portion (at C) toward a closed aft portion (C’; p.3 col.1 l.48 – col.2 l.12, e.g. pleated sheet metal T option shown in Fig 11) such that the cooling airflow flows through the inner faces toward outward faces (A flows through B analogous to the flow of arrows A in Fig 1);
PNG
media_image1.png
346
346
media_image1.png
Greyscale
It would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to modify the condenser heat exchanger of Suciu in view of Sibbach to comprise at least one inclined heat exchanger pair as taught by Jancel in order to provide a heat exchanger that channels and compresses the cooling airflow through the heat exchanger in an adjustable manner, thus mitigating aircraft resistance to forward movement (which increases its aerodynamic qualities), improving heat exchanger efficiency (Jancel, p.1 col.1 l.17 – col.2 l.13), and providing the option of modulating cooling capacity (Jancel, p.3 col.1 ll.5-47).
Suciu in view of Sibbach and Jancel still does not teach a plurality of the condenser heat exchangers pairs (including respective turning portions) circumferentially spaced apart about the propulsor axis, and a plurality of the water separator.
However, Klingels teaches the use of multiple condenser heat exchangers (32) distributed circumferentially spaced apart about the propulsor axis (Figs 1-2) for exchanging heat between core turbine exhaust (from 18) and bypass duct cooling air (flowing in 37; Figs 1-2); and using a plurality of separators (42) in the water separator channel (200) to separate water from the condensed exhaust gas of a turbofan engine. Note that the plurality of water separators, together, receive all the exhaust gas from the all the condensers of the engine system.
It would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to modify the single condenser and single water separator of Suciu in view of Sibbach and Jancel to be multiple condensers and water separators as taught by Klingels because MPEP 2144.04(VI)(B) provides that mere duplication of essential working parts of a device for amplified effect is an obvious extension of prior art teachings, In re Harza, 274 F.2d 669, 124 USPQ 378 (CCPA 1960), MPEP 2144.04 VI B, the amplified effect being increased cooling capacity and water separation.
Regarding claim 20, Suciu in view of Sibbach, Jancel, and Klingels teaches all the limitations of the claimed invention as discussed above.
Suciu in view of Sibbach, Jancel, and Klingels as discussed so far, does not teach generating a steam flow from water extracted from the exhaust gas flow in an evaporator system that exhausts the exhaust gas flow into a corresponding plurality of exhaust ducts.
However, Sibbach further teaches generating a steam flow (176) from water extracted from the exhaust gas flow (via 104, 106, 107, 108) in an evaporator system (incl. 102) that exhausts the exhaust gas flow (66) into a corresponding plurality of exhaust ducts (32; Fig 2).
It would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to modify the system of Suciu in view of Sibbach, Jancel, and Klingels to use the steam system of Sibbach, in order to facilitate increased bypass ratio and thermal efficiency (Sibbach, col.2 l.54 – col.3 l.28).
Claim 6 is/are rejected under 35 U.S.C. 103 as being unpatentable over Suciu in view of Sibbach, Jancel, and Klingels, and further in view of Stuart 5369954.
Regarding claim 6, Suciu in view of Sibbach, Jancel, and Klingels teaches all the limitations of the claimed invention as discussed above (including each condensing heat exchanger comprising a condenser pair). Suciu in view of Sibbach, Jancel, and Klingels as discussed so far, does not teach each of the plurality of strut portions of the exhaust duct assembly are in flow communication with at least two of the plurality of condenser pairs.
However, Klingels further teaches each of a plurality of strut portions (each C-duct, or each circumferential end thereof, comprising a radial structure, is interpreted as a strut portion providing support in the radial direction to resist pressure in the radial direction; per Merriam Webster definition for “strut” : “a structural piece designed to resist pressure in the direction of its length”, wherein a “structural piece” is reasonably interpreted to comprise multiple parts) of the exhaust duct assembly being flow communication with at least two condenser heat exchange modules (in this case, there are two C-ducts, and four circumferentially ends of the C-ducts, such that each C-duct/circumferential-end is in flow communication with at least two condensing heat exchange modules 32).
And Stuart teaches using C-ducts in the exhaust assembly of the turbofan in order to provide access to the core engine while maintaining structural integrity by reacting principal stresses as hoop stresses (col.2 ll.17-27, 37-45; col.5 ll.1-4). The arrangement also being advantageous in facilitating a non-circular, increased-diameter nozzle to accommodate increased bypass ratio with minimal increase in engine height (col.1 l.33 – col.2 l.10).
It would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to modify the nondescript strut/condenser relationship of Suciu in view of Sibbach, Jancel, and Klingels, to comprise the multiple-to-one condenser-strut relationship using c-ducts as taught by Klingels, in order to provide access to the core engine while maintaining structural integrity by reacting principal stresses as hoop stresses (Stuart, col.2 ll.17-27, 37-45; col.5 ll.1-4).
Claim 12 is/are rejected under 35 U.S.C. 103 as being unpatentable over Suciu in view of Sibbach, Jancel, and Klingels, and further in view of Reynolds 6293086 and Payling 6470668.
Regarding claim 12, Suciu in view of Sibbach, Jancel, and Klingels teaches all the limitations of the claimed invention as discussed above.
Suciu in view of Sibbach, Jancel, and Klingels as discussed so far, does not teach an intercooling system where a portion of the water recovered from the exhaust gas flow is injected into the compressor for cooling a core flow.
However, Reynolds teaches an intercooling system (incl. 19, 21, 23) where a portion (21) of water (32) recovered from the exhaust gas flow (exhaust efflux, col.3 ll.15-16) is injected into the compressor for cooling a core flow (at 11, 12, 23; Figs 1-2).
And Payling teaches that water injection intercooling provides both increased power output and increased thermal efficiency (col.1 ll.38-50, 58-62; col.3 ll.50-65).
It would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to modify Suciu in view of Sibbach, Jancel, and Klingels to use the steam injected intercooling as taught by Reynolds, in order to provide both increased power output and increased thermal efficiency (Payling; col.1 ll.38-50, 58-62; col.3 ll.50-65) while making use of recovered water from the exhaust (Reynolds, col.3 ll.15-36).
Response to Arguments
Applicant’s arguments filed 23 December 2025 have been fully considered but they are not persuasive.
Applicant argues that Jancel does not teach the forward and aft faces now claimed.
However, as discussed above, Jancel does teach such forward and aft faces (where B, B’ meet C, C’). Note, the terms forward and aft are not provided with any particular definition. Thus, they are interpreted corresponding to the flow direction through the heat exchanger pair in the case of Jancel.
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.
Correspondence
Any inquiry concerning this communication or earlier communications from the examiner should be directed to STEPHANIE SEBASCO CHENG whose telephone number is (469)295-9153. The examiner can normally be reached on 1000-1600 ET.
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, Devon Kramer can be reached on (571-270-5426. The fax phone number for the organization where this application or proceeding is assigned is 571-273-8300.
Information regarding the status of an application may be obtained from the Patent Application Information Retrieval (PAIR) system. Status information for published applications may be obtained from either Private PAIR or Public PAIR. Status information for unpublished applications is available through Private PAIR only. For more information about the PAIR system, see http://pair-direct.uspto.gov. Should you have questions on access to the Private PAIR system, contact the Electronic Business Center (EBC) at 866-217-9197 (toll-free). If you would like assistance from a USPTO Customer Service Representative or access to the automated information system, call 800-786-9199 (IN USA OR CANADA) or 571-272-1000.
/STEPHANIE SEBASCO CHENG/Primary Examiner, Art Unit 3741