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 .
Claim Rejections - 35 USC § 112
The following is a quotation of the first paragraph of 35 U.S.C. 112(a):
(a) IN GENERAL.—The specification shall contain a written description of the invention, and of the manner and process of making and using it, in such full, clear, concise, and exact terms as to enable any person skilled in the art to which it pertains, or with which it is most nearly connected, to make and use the same, and shall set forth the best mode contemplated by the inventor or joint inventor of carrying out the invention.
The following is a quotation of the first paragraph of pre-AIA 35 U.S.C. 112:
The specification shall contain a written description of the invention, and of the manner and process of making and using it, in such full, clear, concise, and exact terms as to enable any person skilled in the art to which it pertains, or with which it is most nearly connected, to make and use the same, and shall set forth the best mode contemplated by the inventor of carrying out his invention.
Claims 1-3, 6-13, 16-19 and 21 are rejected under 35 U.S.C. 112(a) or 35 U.S.C. 112 (pre-AIA ), first paragraph, as failing to comply with the written description requirement. The claim(s) contains subject matter which was not described in the specification in such a way as to reasonably convey to one skilled in the relevant art that the inventor or a joint inventor, or for applications subject to pre-AIA 35 U.S.C. 112, the inventor(s), at the time the application was filed, had possession of the claimed invention. Regarding claim 1, the limitation “a combustor configured to operate with the substantially completely diatomic hydrogen fuel flow, the fuel flow being without diluent… and, at least one set of dilution openings located in the dome wall and fluidly coupled to the combustion chamber” is not supported in the original disclosure. Similarly regarding new claim 21, the limitation “a combustor configured to operate with substantially completely diatomic hydrogen fuel flow, the fuel flow being without diluent… wherein the dome wall is configured to provide one of a swirl flow to the combustion chamber or a cooling flow” is also not supported in the original disclosure. The amendment finds support at one location in the specification, para. [0080]. The relevant text of the disclosure states “[w]ith the combustor sized as described in these embodiments, hydrogen fuel can be used without the need of diluents. In some embodiments, no diluent is added to the combustion chamber 430 and the fuel is substantially completely diatomic hydrogen without diluent.” Thus, the specification makes clear that the use of substantially completely diatomic hydrogen without diluent occurs in those embodiments where no diluent is added to the combustion chamber. Thus, the use of hydrogen without diluent is exclusive of the elected embodiment and not disclosed to be consistent with a combustor having at least one set of dilution openings in the dome wall.
Claims dependent thereon are rejected for the same reasons.
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 (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.
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, 6, 16, 18-19, 21 are is/are rejected under 35 U.S.C. 103 as being unpatentable over Roberts US 5,335,502, in view of Donisi US 2020/0165937 and Joshi US 11,578,871.
Regarding claim 1, Roberts discloses a gas turbine engine, see fig. 1 comprising: a fuel delivery assembly 52, 74, etc configured to deliver a fuel flow, fuel from fuel injector 52; a compressor section 20, 22 configured to compress air flowing therethrough to provide a compressed air flow; and a combustion section 24 comprising a fuel injector 52 and a combustor configured to operate with the substantially completely diatomic hydrogen fuel flow, the fuel flow being without diluent, the combustor is capable of burning hydrogen without diluent, the combustor including an inner liner 60, an outer liner 58, a dome wall 64, and a combustion chamber 62, the combustion chamber characterized by a combustor size rating between one inch and seven inches, see col. 6, line 62-col, 7, line 5 showing a combustor size rating of 1.5, at a core air flow parameter, wherein the combustor size rating is a function of the core air flow parameter, and wherein the combustor size rating is defined by : L2/H, wherein H is a maximum height of the combustion chamber measured by a forward line extending from an inner surface of the outer liner to an inner surface of the inner liner, referring to fig. 2, the diameter is taken at the forward end of the combustor as claimed and L is a length of the combustion chamber measured from a midpoint of the forward line to a midpoint of an aft line, and L is the length that extends as claimed, the aft line extending from the inner surface of the inner liner to the inner surface of the outer liner at a leading edge of a turbine nozzle 26, and wherein the core air flow parameter is defined by Thrust/Bypass ratio. Roberts does not expressly state the system is a hydrogen fuel delivery system comprising substantially completely diatomic hydrogen or that the core air flow parameter is between two and one half kN and sixty kN or at least one set of dilution openings located in the dome wall and fluidly coupled to the combustion chamber.
Donisi teaches a gas turbine engine similar to that of Roberts and states that GT engines may have any desired maximum thrust from 160kN-550kN, see para. [0077], and bypass ratios may be any desired ratio from 10-17, see para. [0074]. This results in a core airflow parameter from 9.4-55.
It would have been obvious to an ordinary skilled worker to provide a thrust and bypass ratio in the engine of Roberts from between 160-550kN and 10-17, respectively, as taught by Donisi, in order to provide a desired engine characteristic. Supra. Roberts in view of Donisi, does not teach the claimed dilution openings or the use of hydrogen fuel as claimed.
Joshi teaches a similar combustor to Roberts where the engine utilizes hydrogen as a first amount of fuel F1 that is hydrogen and injected into injector 30, see col. 7, lines 5-10. The use of hydrogen allows for reduced combustor volume because there is no length of time needed for evaporation, mixing is fast, and reaction rates are high so that length and weight can be reduced by decreasing combustor volume and length. See col. 8, lines 51-57. Joshi also shows that dilution openings 48 are formed in the dome to provide dilution cooling to provide cooling or mixing. See col. 6, lines 44-59.
It would have been obvious to an ordinary skilled worker to provide hydrogen fuel to the engine of Roberts, in view of Donisi, and to provide dilution cooling in the dome as claimed in order to provide a smaller and lighter engine and to provide cooling and mixing of the fuel. Supra.
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Regarding claim 2, Roberts, in view of Donisi and Joshi, discloses the at least one set of dilution openings are circumferentially arranged about an engine centerline. Referring to fig. 3, Joshi shows an annular combustor having an upper set of dilution holes 48 that would be arranged about the engine centerline circumferentially.
Regarding claim 3, Roberts, in view of Donisi and Joshi, discloses the at least one set of dilution openings is a first set of dilution openings and a second set of dilution openings concentric with respect to each other. As discussed in claim 2, Joshi shows an annular combustor with a first set being the upper set and the second set being the lower set, where the lower set is within the upper set, i.e. in concentric arrangement to each other.
Regarding claim 6, Roberts, in view of Donisi and Joshi, discloses the at least one set of dilution openings extends between a dilution inlet and a dilution outlet at the dome wall. Referring to fig 3, Joshi shows a dilution cooling passage which has an inlet on the left side of the dome and an outlet on the right side of the dome.
Regarding claim 16, Roberts, in view of Donisi and Joshi, discloses the least one set of dilution openings are circumferentially disposed about a dome inlet. Joshi teaches the dilution holes can define a swirler provided in the dome inlet 54. See fig. 2, col. 5, lines 25-40.
Regarding claims 18-19, Roberts, in view of Donisi and Joshi, discloses the combustor size rating is based on a thrust of the gas turbine engine and the thrust is between 60-500 kN. Donisi teaches the engine thrust should be between 160-550 kN and the combustor size is directly related thereto.
Regarding claim 21, referring to claim 1 above, Roberts, in view of Donisi and Joshi, discloses all elements as discussed above where the dome wall is configured to provide one of a swirl flow to the combustion chamber of a cooling flow. As discussed above, Joshi teaches a dilution cooling flow that provides swirling. See col. 6, lines 44-59.
Claim(s) 17 are is/are rejected under 35 U.S.C. 103 as being unpatentable over Roberts US 5,335,502, in view of Donisi US 2020/0165937 and Joshi US 11,578,871 and Chen US 2009/0199563.
Regarding claim 17, Roberts, in view of Donisi and Joshi, discloses all elements except the combustor size rating is between two inches and three and one quarter inches. Donisi teaches the core flow parameter of between 9-50 kN.
Chen teaches that the size of the combustor can vary based on application. In some applications a combustor can have a size rating of up to 4. See para. [0037].
It would have been obvious to an ordinary skilled worker to provide a combustor size rating of up to 4 in the engine of Roberts, in view of Donisi and Joshi, as taught by Chen, in order to provide the desired performance for a particular application. Id.
Claim(s) 7-8 is/are rejected under 35 U.S.C. 103 as being unpatentable over Roberts, in view of Donisi and Joshi, as applied to claim 6 above, and further in view of Shekleton US 4,949,545.
Regarding claim 7, Roberts, in view of Donisi and Joshi, discloses all elements but does not teach that at least one vane disposed within the at least one set of dilution openings between the dilution inlet and the dilution outlet.
Shekleton teaches a dilution cooling hole 124 having a swirler 130 within the space so as to provide swirl to the cooling flow introduced in the combustion chamber. See col. 5, line 62-col. 6, line 7. The swirling cooling flow supports more uniform mixture of fuel and air to minimize hot and cold spots. See col. 1, lines 35-46.
It would have been obvious to an ordinary skilled worker to provide a swirling vane in the dilution holes of Roberts, in view of Donisi and Joshi, as taught by Shekleton, in order to promote better mixing to avoid hot and cold spots. Id.
Regarding claim 8, Roberts, in view of Donisi, Joshi, and Shekleton, discloses the at least one vane is an axial flow vane. See Shekleton, fig. 5.
Claim(s) 9 is/are rejected under 35 U.S.C. 103 as being unpatentable over Roberts, in view of Donisi and Joshi, as applied to claim 6 above, and further in view of Alkabie US 2007/0271925.
Regarding claim 9, Roberts, in view of Donisi and Joshi, discloses all elements except for a dome inlet defines a dome centerline and each dilution opening of the at least one set of dilution openings defines a dilution centerline and wherein the dilution centerline is a first centerline angled toward a longitudinal axis and intersecting with dome centerline to define a dilution angle. Rather, Roberts, in view of Donisi and Joshi, is silent to the angle of the dilution hole and at best shows a dilution angle parallel to the longitudinal axis.
Alkabie teaches that the direction of the cooling holes 48 may be a varying angle some of which such as 46a are oriented as claimed. The angling of the cooling holes act to energize decaying swirl of the combustion gas flow which increases fuel mixing processes. See para. [0035].
It would have been obvious to an ordinary skilled worker to provide an angle to the dilution cooling holes of Roberts, in view of Donisi and Joshi, so that the dome inlet defines a centerline and each of the dilution openings defines a respective dilution centerline such that the dilution centerline is a first centerline angled toward a longitudinal axis and intersecting with the dome centerline to form a dilution angle, as taught by Alkabie, in order to increase fuel mixing processes. Id.
Allowable Subject Matter
Claims 10-13 are objected to as being dependent upon a rejected base claim, but would be allowable if rewritten in independent form including all of the limitations of the base claim and any intervening claims and correction of the indefiniteness issues raised above.
The following is a statement of reasons for the indication of allowable subject matter: Regarding claim 10, the prior art does not appear to teach or fairly suggest the claimed conic portion, the flat portion or their relative placements as claimed. Claims dependent thereon are allowable for the same reasons.
Regarding claim 13, the prior art does not appear to disclose a flare cone and purge passage as claimed.
Response to Arguments
Applicant’s arguments with respect to the claim(s) 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.
The Applicant argues that the amendment warrants removal of the new matter and indefiniteness rejections. The Examiner disagrees. The Amendment provided herein derives from one paragraph in the specification. At para. [0080], the specification makes clear that the use of diatomic hydrogen without diluent is in the embodiments where the combustor is configured to operate without diluents. While it is potentially conceivable to utilize hydrogen without any diluents mixed in, the specification makes clear that the embodiment in which this is contemplated is not compatible with the combustor having a diluent. Thus, while an indefiniteness rejection is withheld, the amendment still raises the same new matter issue.
Additionally, since the combustor is now recited with dilution cooling, new prior art is applied in view of the change of scope in the claims.
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 GERALD LUTHER SUNG whose telephone number is (571)270-3765. The examiner can normally be reached 9-5 PST.
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/GERALD L SUNG/Primary Examiner, Art Unit 3741