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 .
Claims 1-11 are currently pending. Claims 1-11 are rejected.
Information Disclosure Statement
The information disclosure statements (IDS) submitted on April 17, 2025, May 01, 2025, June 09, 2026 are in compliance with the provisions of 37 CFR 1.97. Accordingly, the information disclosure statements are being considered by the examiner.
Claim Objections
Claims 8-11 are objected to because of the following informalities:
Regarding Claim 8, Lines 1-2 recite “at least one impeller a casing”. It is believed these were intended to be two separate clauses missing a punctuation.
Claims 9-11 are subsequently objected to for their dependencies upon a previously rejected claim.
Appropriate correction is required.
Claim Rejections - 35 USC § 112(b)
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.
Claims 8-11 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 applications subject to pre-AIA 35 U.S.C. 112, the applicant), regards as the invention.
Regarding Claim 8, Line 2 recites “the housing”. There is insufficient antecedent basis for this limitation in the claim, since it has not been previously introduced. It is unclear if this is a new limitation or intended to reference the previously recited casing.
Regarding Claim 8, Lines 4-5 recite “the inboard side” and “outboard”. There is insufficient antecedent basis for the inboard side, since it has not been previously introduced. It is unclear where inboard and outboard are intended to be, as there is no previously indicated frame of reference.
Regarding Claim 8, Lines 13-14 recite “retuning at least the leaking process gas to the process gas path”. It is unclear what is meant to retune gas. It is believed this may be a typographical error.
Claims 9-11 are subsequently rejected for their dependencies upon a previously rejected claim.
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.
This application currently names joint inventors. In considering patentability of the claims the examiner presumes that the subject matter of the various claims was commonly owned as of the effective filing date of the claimed invention(s) absent any evidence to the contrary. Applicant is advised of the obligation under 37 CFR 1.56 to point out the inventor and effective filing dates of each claim that was not commonly owned as of the effective filing date of the later invention in order for the examiner to consider the applicability of 35 U.S.C. 102(b)(2)(C) for any potential 35 U.S.C. 102(a)(2) prior art against the later invention.
Claims 1-4, 6-10 are rejected under 35 U.S.C. 103 as being unpatentable over Shamseldin et al. (US 2009/0290971 A1), hereinafter Shamseldin, in view of Bardon et al. (US 2014/0225325 A1), hereinafter Bardon.
Regarding Claim 1, Figure 1 of Shamseldin teaches a turbomachine comprising: a casing (104); a rotor (106 side, not shown [0020]) rotatably supported in the casing (104) and comprising at least one impeller; at least one bearing (108 side, not shown [0020]) rotatably supporting the rotor in the casing (104); and a dry gas seal arrangement (100) disposed between the rotor and the bearing, wherein the dry gas seal arrangement (100) has an inboard side (left side in view of Figure 1) facing the rotor and an outboard side (right side in view of Figure 1) facing the bearing; the dry gas seal arrangement (100) comprises: a primary dry gas seal (110) at the inboard side of said dry gas seal arrangement (100); a primary seal gas supply (148), fluidly coupled to a process gas path (148 receives from 106), and through which gas processed by the turbomachine is supplied to the primary dry gas seal (110); a secondary dry gas seal (111) disposed adjacent to the primary dry gas seal (110) outboard of the primary dry gas seal (110); a secondary seal gas supply (156), fluidly coupled to a source of inert seal gas (inert gas, such as nitrogen) and adapted to buffer the secondary dry gas seal (111) with said inert seal gas; a primary vent (154), fluidly coupled to the primary dry gas seal (110) and to the secondary dry gas seal (111) and adapted to collect process gas leaking form the primary gas seal (110) and inert seal gas leaking from the secondary dry gas seal (111) at a first venting pressure; and a secondary vent (158), fluidly coupled to the secondary dry gas seal (111) and outboard thereof and adapted to collect inert seal gas leaking from the secondary dry gas seal (111) [0020-0021, 0026-0035].
Shamseldin does not expressly teach the primary vent to return at least the leaking process gas toward the process gas path as claimed. However, return of the gas would have been obvious in view of Bardon.
Figure 4 of Bardon teaches a dry gas seal arrangement with a primary vent (214) configured to return at least the leaking process gas (from 310) toward the process gas path. The primary vent also intakes the inert seal gas from (312) like the primary vent of Shamseldin (Bardon, [0004, 0044], Shamseldin, [0029, 0033]). As described in paragraph [0004] of Bardon, the return of the process gas (sealing gas) is desirable to improving the efficiency of the compressor.
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 turbomachine taught by Shamseldin such that the primary vent is configured to return at least the leaking process gas toward the process gas path as suggested by Bardon, to provide the benefit of increasing compressor efficiency.
Regarding Claim 2, Shamseldin and Bardon teach the turbomachine as set forth in Claim 1.
Figure 1 of Shamseldin teaches a labyrinth seal (152) between the primary dry gas seal (110) and the secondary dry gas seal (111), wherein the labyrinth seal (152) is buffered by said inert gas (from 156) [0029, 0034].
Regarding Claim 3, Shamseldin and Bardon teach the turbomachine as set forth in Claim 1.
Shamseldin teaches wherein the inert gas is nitrogen [0026].
Regarding Claim 4, Shamseldin and Bardon teach the turbomachine as set forth in Claim 1.
Figure 1 of Shamseldin teaches a separation seal (144) arranged outboard of the secondary dry gas seal (111), arranged between the secondary dry gas seal (111) and the bearing (in 108, not shown); and a separation gas supply port (162) adapted to supply a separation gas to the separation seal (144), wherein the secondary vent (158) is arranged between the secondary dry gas seal (111) and the separation seal (144) [0020, 0025, 0031].
Regarding Claim 6, Shamseldin and Bardon teach the turbomachine as set forth in Claim 1.
The modification in Claim 1 by Bardon results wherein the primary vent is fluidly coupled to the process gas path, to return a mixture of process gas leaking through the primary dry gas seal and inert gas leaking from the secondary dry gas seal toward the gas path. Figure 1 of Shamseldin shows a primary vent (154) that takes a mixture of the process gas (from 148) and the inert gas (from 156) (Shamseldin, [0033-0034]). Figure 4 of Bardon also shows a primary vent (214) that receives a mixture of process gas (from 310) and inert gas (from 312) (Bardon, [0044]). The modification of Shamseldin with Bardon has this mixture returned to the process gas path by the primary vent being coupled to the process gas path for improving efficiency (Bardon, [0004]).
Regarding Claim 7, Shamseldin and Bardon teach the turbomachine as set forth in Claim 1.
Figure 1 of Shamseldin teaches an inner labyrinth seal (128) inboard of the primary dry gas seal (110) [0020].
Regarding Claim 8, as far as it is definite and understood, Shamseldin teaches a method for sealing a turbomachine comprising: a rotor (106 side, not shown [0020]) having at least one impeller a casing (104); a bearing (108 side, not shown [0020]) rotatably supporting the rotor in the housing (104); and a dry gas seal arrangement (100) between the rotor and the bearing; wherein the dry gas seal arrangement (100) comprises: a primary dry gas seal (110) at the inboard side (left side in view of Figure 1) of said dry gas seal arrangement (100); a secondary dry gas seal (111) disposed adjacent to the primary dry gas seal (110) outboard of the primary dry gas seal (110); the method comprising the following steps: processing a process gas (148 receives from 106) through a process gas path (106 side), wherein the process gas path comprises the turbomachine; supplying process gas (from 148) as a primary sealing dry gas to the primary dry gas seal (110); supplying an inert gas (can be nitrogen) as a secondary dry gas (from 156) to the secondary dry gas seal (111) and buffering the secondary dry gas seal (111) with the inert gas; collecting process gas leaking from the primary dry gas seal (110) and inert gas leaking from the secondary dry gas seal (111) in a primary vent (154); and collecting inert gas leaking from the secondary dry gas seal (111) in a secondary vent (158) [0020-0021, 0026-0035].
Shamseldin does not expressly teach retuning (believed to be a typo of “returning”) at least the leaking process gas to the process gas path as claimed. However, returning would have been obvious in view of Bardon.
Figure 4 of Bardon teaches a method for sealing a turbomachine comprising a dry gas seal arrangement with a primary vent (214) collecting leaking process gas. The method comprises returning at least the leaking process gas (from 310) to the process gas path. The primary vent also intakes the inert seal gas from (312) like the primary vent of Shamseldin (Bardon, [0004, 0044], Shamseldin, [0029, 0033]). As described in paragraph [0004] of Bardon, the return of the process gas (sealing gas) is desirable to improving the efficiency of the compressor.
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 method taught by Shamseldin with the step of returning at least the leaking process gas toward the process gas path as suggested by Bardon, to provide the benefit of increasing compressor efficiency.
Regarding Claim 9, as far as it is definite and understood, Shamseldin and Bardon teach the method as set forth in Claim 8.
Figure 1 of Shamseldin teaches wherein a labyrinth seal (152) is arranged between the primary dry gas seal (110) and the secondary dry gas seal (111), and wherein inert gas (from 156) flows from the secondary dry gas seal (111) towards the primary vent (154) through the labyrinth seal (152) [0029, 0034].
Regarding Claim 10, as far as it is definite and understood, Shamseldin and Bardon teach the method as set forth in Claim 8.
Figure 1 of Shamseldin teaches wherein a separation seal (144) is arranged between the secondary dry gas seal (111) and the bearing (108 side, not shown); the method further comprising the step of buffering the separation seal (144) with inert gas (from 162) [0020, 0025, 0031].
Claims 5 and 11 are rejected under 35 U.S.C. 103 as being unpatentable over Shamseldin and Bardon as applied to Claims 1 and 8 above, and further in view of Watanabe et al. (US 2018/0120007 A1), hereinafter Watanabe
Regarding Claim 5, Shamseldin and Bardon teach the turbomachine as set forth in Claim 1.
Shamseldin and Bardon do not expressly teach a gas separator fluidly coupled to the primary vent and adapted to separate process gas and inert gas from one another, wherein the separator is fluidly coupled to the process gas path for returning the separated process gas leaking through the primary dry gas seal to the process gas path as claimed. However, a separator would have been obvious in view of Watanabe.
Figures 2-3 of Watanabe teaches a turbomachine having a primary vent (18) for venting a mixture of process gas (G1) and inert gas (G2 from 21, unlabeled in Figure 2). Watanabe includes a gas separator (30) fluidly coupled to the primary vent (18) and adapted to separate process gas (G1) and inert gas (G2) from one another, wherein the separator is fluidly coupled to the process gas path for returning the separated process gas (G1) leaking through the primary dry gas seal (17A) to the process gas path (through 34) [0045, 0055]. Through separation, it is possible to recover the process gas and inert gas separately, which allows supplying of the process gas to the compressor, reducing the amount of process gas needed to be additionally supplied to the compressor [0008-0009]. See also Bardon paragraph [0006], which acknowledges negative impacts from feeding the compressor inert gas.
It would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to further modify the turbomachine taught by Shamseldin-Bardon with a gas separator fluidly coupled to the primary vent and adapted to separate process gas and inert gas from one another, wherein the separator is fluidly coupled to the process gas path for returning the separated process gas leaking through the primary dry gas seal to the process gas path as suggested by Watanabe, to provide the benefit of separately recovering the process gas and inert gas so that only process gas is fed to the reused in the compressor.
Regarding Claim 11, as far as it is definite and understood, Shamseldin and Bardon teach the method as set forth in Claim 8.
Shamseldin and Bardon do not expressly teach the step of separating inert gas from process gas venting through the primary vent and reintroducing the process gas in the process gas path as claimed. However, such a step would have been obvious in view if Watanabe.
Figures 2-3 of Watanabe teaches a turbomachine having a primary vent (18) for venting a mixture of process gas (G1) and inert gas (G2 from 21, unlabeled in Figure 2). Watanabe teaches a method with the step of separating (via separator 30) inert gas (G2) from process gas (G1) venting through the primary vent (18) and reintroducing the process gas (G1) in the process gas path (through 34) [0045, 0055]. Through separation, it is possible to recover the process gas and inert gas separately, which allows supplying of the process gas to the compressor, reducing the amount of process gas needed to be additionally supplied to the compressor [0008-0009]. See also Bardon paragraph [0006], which acknowledges negative impacts from feeding the compressor inert gas.
It would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to further modify the method taught by Shamseldin-Bardon with the step of separating inert gas from process gas venting through the primary vent and reintroducing the process gas in the process gas path as suggested by Watanabe, to provide the benefit of separately recovering the process gas and inert gas so that only process gas is fed to the reused in the compressor.
Conclusion
Any inquiry concerning this communication or earlier communications from the examiner should be directed to ELTON K WONG whose telephone number is (408)918-7626. The examiner can normally be reached Mon-Fri 8:00AM - 5:00PM PST.
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/ELTON K WONG/Primary Examiner, Art Unit 3745
