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and the fee set forth in 37 CFR 1.17(e) has been timely paid, the finality of the previous Office action has been withdrawn pursuant to 37 CFR 1.114.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 7/8/2026 has been entered.
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 1-8 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.
Claim 1 recites “wherein flow rates of the respective divided flows are independently adjustable to separately control a pre-cooling process and a liquefaction process of the natural gas”. While the specification does discuss the flow rates being adjusted (paragraphs 52-53 and 81) there is no discussion of them being “independently adjustable”, which term is both broad and indefinite. The specification appears to only recite that the turboexpanders can adjust the temperature with the flow rate or that the flow rates can be adjusted (paragraph 79) but as the specification does not recite any specific way this is done such limitation is not supported by the specification and as such the limitation is considered to lack written description in the specification and be new matter.
Claim 1 recites “wherein the at least two divided flows are respectively configured to circulate through different temperature regions of the cryogenic heat exchanger including a warm region and an intermediate region” which is considered indefinite. It is unclear how the claim is written if the respective flows are each required to pass through a warm region and an intermediate region, or if between the two divided flows this is the required configuration. For the purpose of examination, this limitation is understood that as long as at least one divided flow passes through an intermediate region of the heat exchanger and another divided flow passes through a warm region of the heat exchanger, the limitation is met.
Claims 2-8 are rejected as being dependent upon a rejected claim.
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 1-8 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.
Claim 1 recites “wherein flow rates of the respective divided flows are independently adjustable” which is considered indefinite as it is unclear what “independently adjustable” means in this context as independently adjustable can have several meanings and even in view of the specification it is unclear what is meant by the claim language. The instant specification only discusses that the turbo expanders can adjust the temperature difference with the flow rates (paragraphs 52-53) and that the flow rates are adjusted (paragraph 81) but there is no discussion of how this is done specifically, any control system to do so or how they would be adjusted independently. For the purpose of examination, this limitation is understood that there has to be separate ways of controlling each adjusted flow rate such as separate valves which control each, or where each turboexpander or pre-compressed stream has the flow rate adjusted as opposed to the split in the fluid being controlled to provide the adjustment.
Claim 6 provides recitations in regards to “a warm heat exchanger region” and “an intermediate heat exchanger region and a warm heat exchange region” which is considered indefinite as it is unclear how these recitations relate to the limitations of intermediate region and warm region in claim 1. For the purpose of examination, these limitations are understood to be specifically requiring a configuration in relation to how the flows pass through the specifically claimed regions.
Claim 8 recites “an intermediate region” and a “warm heat exchange region” which is considered indefinite as it is as it is unclear how this relates to the intermediate region and warm region respectively already recited in claim 1. For the purpose of examination, they are not considered to be required to be the same regions.
Claims 2-5, 7-8 are rejected as being dependent upon a 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.
Claim(s) 1-8 is/are rejected under 35 U.S.C. 103 as being unpatentable over Seitter et al. (US PG Pub 20160061517), hereinafter referred to as Seitter and Wyllie et al. (US PG Pub 20140245780), hereinafter referred to as Wylie and Alers et al. (US PG Pub 20110168377), hereinafter referred to as Alers.
With respect to claim 1, Seitter (Figure 1) teaches a natural gas liquefaction apparatus comprising: a cryogenic heat exchanger through which natural gas passes through and is liquefied into liquefied natural gas through heat exchange with a first refrigerant and a second refrigerant (first refrigeration system 12 and second refrigeration system 14 each having a refrigerant, which can a single heat exchanger, paragraph 39 with multiple zones, which produces LNG, paragraph 40);
a first refrigerant cycle through which the first refrigerant circulates, which has some paths passing through the cryogenic heat exchanger to perform heat exchange (first refrigerant cycle is the one of first refrigeration system 12 which has flow paths through zones 20, 26, and 32, paragraph 34-35),
and which has a path of the first refrigerant divided into a plurality of paths after performing heat exchange at the cryogenic heat exchanger (the refrigerant from the first cycle splits into streams via conduits 136, 142 and 152 after passing through portions of the heat exchanger, paragraph 52, 59, 66), wherein each of the plurality of paths is configured to carry a respective flow of the first refrigerant (all three split paths carry portions of the refrigerant),
and performs expansion of the first refrigerant through the paths using at least two expanders (the streams from 136, 152 and 142 are expanded in 60, 64 and 70 respectively which can be hydraulic turbines, paragraphs 52, 59 and 66),
wherein the at least two divided flows are respectively configured to circulate through different temperature regions of the cryogenic heat exchange including a warm region and an intermediate region (the stream from 60 which is one of the divided flows passes through heat exchanger region 20, which is a warm region and the stream from 64 which is one of the divided stream passes through heat exchange region 26 which can be considered at least in part an intermediate region).
and a second refrigerant cycle through which the second refrigerant circulates and which has some paths passing through the cryogenic heat exchanger (second refrigeration system 14 has multiple pathways in the heat exchanger, paragraphs 86-87, 90).
Seitter does not teach the first refrigerant cycle is configured to perform pre-compression of at least two divided flows of the first refrigerant through the plurality of paths by at least two respective first refrigerant turbo expanders, and to mix the at least two divided flows of the first refrigerant pre-compressed by the at least two respective first refrigerant turbo expanders at the same pressure and transfer the mixed flows to a first refrigerant first compression part.
Wyllie (Figure 3) teaches a system substantially similar to that of the Seitter where after individual streams are expanded, they are combined and compressed together (paragraphs 66-68), but teaches an alternative embodiment (Figure 5) where a single stream of refrigerant (CS) that is fed into the heat exchanger is split into three separate streams (HS, IS, LS) and after expansion (HS in HE, IS in IE, LS in LE) each stream passes through the heat exchanger where it is warmed is fed to a respective compressor in parallel (HC for expanded HS, IC for expanded IS, LC for expanded LS) which are configured as turboexpanders before the streams are all combined during further compression (Paragraphs 86-89). As seen in the figure the stream from LE traverses from the coldest to the warmest part of the heat exchanger, the stream from IE traverses from an intermediate part of the heat exchanger to the warm part of the heat exchanger, and the stream from HE traverses the coldest part of the heat exchanger.
Therefore it would have been obvious to a person having ordinary skill in the art at the time the invention as filed to have provided upstream of the compressor system (48) to have provided a compressor on each of the flow lines (128, 146, and 156) of Seitter which is coupled to the respective expander (60, 64, 70) for each flow path in the configuration of a turboexpander (which is what would be required for them to be coupled) based on the teaching of Wyllie since it has been shown that combining prior art elements to yield predictable results is obvious whereby it is desirable as taught by Wyllie to reduce the power demands of a refrigeration cycle (paragraph 7) and it would be common knowledge in the art that providing compression in part by using the expansion energy in the configuration as shown by Wyllie would allow for a reduction in the remaining compression requirement which would reduce the overall power requirement for the refrigeration cycle. This configuration would result in an expander coupled to a compressor, for each of the three divided flow paths, which compression would come after the divided flow paths are used for providing cooling and such compression can be considered pre-compression as it is followed by whatever additional compression is required in the compressor system. This would meet the limitation as claimed as the divided flow on 128 would be “pre-compressed” in a compressor and mixed after compressor stage 54 or further together in 50 with the “pre-compressed” stream from the compressor on the line 146 such that when they are mixed they would be at the same pressure before they are passed to compressor stage (50 or 52) which would be a first refrigerant first compression part.
Seitter does not teach wherein flow rates of the respective divided flows are independently adjustable to control a pre-cooling process and a liquefaction process of the natural gas.
Alers teaches that individual refrigerant streams of a split refrigerant in a refrigerant cycle (100) can be provide with refrigerant valves (170 and 210) to control the flow rate of each refrigerant stream after expansion (paragraphs 52-53).
Therefore it would have been obvious to a person having ordinary skill in the art at the time the invention was filed to have based on the teaching of Alers provided on each of the divided refrigerant stream after expansion (after 60, 64, 70) valves that are able to control the respective flow rates of each refrigerant stream in Seitter as modified since it has been shown that combining prior art elements to yield predictable results is obvious whereby providing control valves would allow what would be common knowledge in the art of the flow rates of the refrigerant to be adjusted to match a desired flow rate to provide better control of the cooling and liquefaction process. As there is pre-cooling, cooling and liquefaction with the three streams who’s flow rate is controlled, the presence of valves as in Seitter as modified meets the limitation as claimed.
With respect to claim 2, Seitter as modified teaches wherein the first refrigerant cycle comprises: a first refrigerant first compression part provided upstream of the cryogenic heat exchanger and configured to compress the first refrigerant to a high pressure (third compressor stage 50, paragraphs 48-49 which results in the stream being at a pressure that can be considered a high pressure);
and the at least two respective first refrigerant turbo expanders comprise:
a first refrigerant first turbo expander comprising a first refrigerant first expansion part provided downstream of the cryogenic heat exchanger and configured to expand the first flow among the two divided flows of the first refrigerant having passed through the cryogenic heat exchanger (refrigerant from 50 is sent to heat exchanger 20 and after passing through it a portion is separated and expanded in turbine 60 as modified which is part of the turboexpander as modified as the first part of the divided flow), and a first refrigerant pre-compression part configured to pre-compress the first refrigerant which has been expanded by the first refrigerant first expansion part and has passed through the cryogenic heat exchanger again (after expansion, the first part of the refrigerant from 60 passes back into the heat exchanger portion 20 and as modified on line 128 is compressed in a compressor formed as a turboexpander with 60); and
a first refrigerant second expander comprising a first refrigerant second expansion part provided downstream of the cryogenic heat exchanger and configured to expand the second flow among the two divided flows of the first refrigerant having passed through the cryogenic heat exchanger (after more of the refrigerant passes through zone 26, a second portion of the divided flow is expanded in expander 64 which as modified is a turbine), and a first refrigerant second pre-compression part configured to pre-compress the first refrigerant which has been expanded by the first refrigerant second expansion part and has passed through the cryogenic heat exchanger again (after expansion, the second part of the refrigerant from 64 passes back into heat exchanger section 64 and then as modified on line 146 is compressed in a compressor formed as a turboexpander with 64).
With respect to claim 3, Seitter as modified teaches wherein the first refrigerant cycle comprises: a first refrigerant first compression part provided upstream of the cryogenic heat exchanger and configured to compress the first refrigerant to a high pressure (third compressor stage 50, paragraphs 48-49 which results in the stream being at a pressure that can be considered a high pressure);
and the at least two respective first refrigerant turbo expanders comprise:
a first refrigerant first turbo expander comprising a first refrigerant first expansion part provided downstream of the cryogenic heat exchanger and configured to expand the first flow among three divided flows of the first refrigerant having passed through the cryogenic heat exchanger (refrigerant from 50 is sent to heat exchanger 20 and after passing through it a portion is separated and expanded in turbine 60 which is part of the turboexpander as modified as the first part of the divided flow), and a first refrigerant pre-compression part configured to pre-compress the first refrigerant which has been expanded by the first refrigerant first expansion part and has passed through the cryogenic heat exchanger again (after expansion, the first part of the refrigerant from 60 passes back into the heat exchanger portion 20 and as modified on line 128 is compressed in a compressor formed as a turboexpander with 60); and
a first refrigerant second expander comprising a first refrigerant second expansion part provided downstream of the cryogenic heat exchanger and configured to expand the second flow among the two divided flows of the first refrigerant having passed through the cryogenic heat exchanger (after more of the refrigerant passes through zone 26, a second portion of the divided flow is expanded in expander 64 which as modified is a turbine), and a first refrigerant second pre-compression part configured to pre-compress the first refrigerant which has been expanded by the first refrigerant second expansion part and has passed through the cryogenic heat exchanger again (after expansion, the second part of the refrigerant from 64 passes back into heat exchanger section 26 and then as modified on line 146 is compressed in a compressor formed as a turboexpander with 64),
a first refrigerant third expander comprising a first refrigerant third expansion part provided downstream of the cryogenic heat exchanger and configured to expand the third flow among the two divided flows of the first refrigerant having passed through the cryogenic heat exchanger (after more of the refrigerant passes through zone 32, a third portion of the divided flow is expanded in expander 70 which as modified is a turbine), and a first refrigerant third pre-compression part configured to pre-compress the first refrigerant which has been expanded by the first refrigerant third expansion part and has passed through the cryogenic heat exchanger again (after expansion, the third part of the refrigerant from 70 passes back into heat exchanger section 32 and then as modified on line 156 is compressed in a compressor formed as a turboexpander with 70).
With respect to claim 4, Seitter (Figure 1) teaches wherein the first refrigerant compression part is provided in plurality (compressor system 48 comprises multiple compressor stages 54, 52, 50, paragraph 70, which would be a plurality as claimed).
With respect to claim 5, Seitter teaches wherein the second refrigerant cycle comprises:
a second refrigerant compression part provided upstream of the cryogenic heat exchanger and configured to compress the second refrigerant to a high pressure (compressor stage 76, which brings the second refrigerant to a pressure, paragraph 80 which can be considered a high pressure);
and a second refrigerant turbo expander comprising a second refrigerant expansion part provided downstream of the cryogenic heat exchanger and configured to expand the second refrigerant having passed through the cryogenic heat exchanger (refrigerant in conduit 176 has passed through the heat exchanger and is expanded in turbine 90, which can be a hydraulic turbine paragraphs 87-88, a hydraulic turbine would be understood by one having ordinary skill in the art to be a turboexpander, as it is a turbine which expands by isentropic expansion producing work), and a second refrigerant pre-compression part configured to pre-compress the second refrigerant which has been expanded by the second refrigerant expansion part and has passed through the cryogenic heat exchanger again (after passing through 38 from the turbine 90, refrigerant is passed to compressor stage 74, paragraph 79, which as it is upstream of 76 is providing what can be considered pre-compression).
With respect to claim 6, Seitter as modified teaches wherein the first flow of the first refrigerant flowing into the cryogenic heat exchanger from the first refrigerant first expansion part is configured to pass through a warm heat exchange region inside the cryogenic heat exchanger (the first flow of first refrigerant is 136 which passes through the warmest region 20 of the heat exchanger), and the second flow of the first refrigerant flowing into the cryogenic heat exchanger from the first refrigerant second expansion part is configured to sequentially pass through an intermediate heat exchange region and a warm heat exchange region inside the cryogenic heat exchanger (the second flow of refrigerant from 142 is passed to 26 which colder end can be considered an intermediate region of the heat exchanger as it is between ends of the heat exchanger, and is passes through the warm end of 26 which part of 26 can be considered a warm region inside the cryogenic heat exchanger as it is warmer than the cold end of 26 and 32).
With respect to claim 7, Seitter as modified teaches wherein the first refrigerant comprises methane (the first mixed refrigerant can include methane, paragraph 73), and the second refrigerant comprises nitrogen (the second mixed refrigerant can contain nitrogen, paragraph 94).
With respect to claim 8, Seitter as modified teaches wherein the flow of the second refrigerant flowing into the cryogenic heat exchanger from the second refrigerant expansion part is to be configured to sequentially pass through, a cold heat exchange region, an intermediate heat exchange region and a warm heat exchange region, in the cryogenic heat exchanger (from 92, the refrigerant passes through 38, which from the entry into 38 to the outlet of 38 there can be considered a cold heat exchanger region on the coldest side of 38, an intermediate heat exchange region in the middle of 38 and a warm heat exchange region on the warmer side of 38).
Response to Arguments
Applicant's arguments filed 7/8/2026 have been fully considered but they are not persuasive.
Applicant argues (page 8) that “Seitter discloses refrigerant flow through a single heat exchange zone” and even though “different portions of zone 26 may operate at different temperatures does not transform zone 26 into multiple heat exchange regions, nor does it establish that the refrigerant sequentially passes through separate intermediate and warm heat exchanger regions as required by independent claim 1”. This is not persuasive.
The multiple heat exchange regions as claimed are only portions along the heat exchanger laterally, a warmer portion, a middle intermediate portion, and a colder portion, which all heat exchangers would have. The instant specification (paragraph 60) describes them as such where the cold heat exchange region is the downstream region with respect to the flow of natural gas, the intermediate region is the midstream region with respect to the natural gas, which would make the warm region the upstream region with respect to natural gas, and the drawings make it clear, they are just different portions of the same heat exchanger at different parts along the heat exchanger. As such, the heat exchanger of Seitter can be said to also have those regions. The three regions as claimed and disclosed are not "separate" or "distinct" as applicant argues, but just aligned parts of a single heat exchanger only defining where in the heat exchanger a stream is located. While the first region (20) can be considered a warm region, it could also be considered both a warm an intermediate region. Alternatively the middle heat exchange region (26) can be considered to have an intermediate region and a warm region, with the intermediate region being the colder part of that region and the warm region being from the warm part of that region through the first region (20). The three sections are defined in the specification and in the drawings by describing where they are in the heat exchanger. Additionally claim 1 is indefinite and it is not clear that all streams are configured to circulate through different temperature regions such that they circulate sequentially and if that were the case the limitation would also be considered new matter. The claims only have support for some streams passing through the regions as claimed, not for all of the streams passing through the different regions as argued. As long as the heat exchanger has any length along which there is a cold and warm part respectively, there would be a cold, intermediate and warm section. Applicant's arguments in regards to Wylie are moot as the rejection in view of Seitter is maintained.
Applicant’s arguments in regard to the independently adjustable flow rates are moot as neither Seitter or Wylie are used to provide a showing of obvious in this regard.
Applicant’s arguments pages 9-11 are moot as they are only to what is taught by Wylie with arguments as to how the Wylie does not teach the limitations as claimed. In response to applicant's arguments against the references individually, one cannot show nonobviousness by attacking references individually where the rejections are based on combinations of references. See In re Keller, 642 F.2d 413, 208 USPQ 871 (CCPA 1981); In re Merck & Co., 800 F.2d 1091, 231 USPQ 375 (Fed. Cir. 1986). It should be noted that applicant is arguing that Wylie does not teach the individual stream circulating through different temperature regions of the cryogenic heat exchanger stream that have been pre-compressed and then are mixed at the same pressure because Wylie teaches further compressing some of those streams before mixing; however, what is taught by Wylie meets the limitations as claimed. In regards to the first limitation it can clearly be seen in Wylie that the streams from the respective expanders (from LE, IE, and HE) each pass through different parts of the heat exchanger with the coldest stream (LE) passing through the entirety of the heat exchanger, the middle stream (from IE) passing through the intermediate and warmest parts of the heat exchanger and the warmest stream (from HE) passing through the warmest part of the heat exchange, which shows the obviousness of the limitation as claimed in addition to how it is showed in the rejection above. Further, in regards to pre-compression and mixing, the claims require two things to happen, they first require that the two divided flows are pre-compressed, and then they require that the streams which have been pre-compressed be mixed at the same pressure. There is no requirement of how that same pressure is achieved and there is nothing in the claim language that prevents further compression as long as the streams are pressurized to the same pressure when they are mixed and sent to the compressor together.
Conclusion
Any inquiry concerning this communication or earlier communications from the examiner should be directed to BRIAN M KING whose telephone number is (571)272-2816. The examiner can normally be reached Monday - Friday, 0800-1700.
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If attempts to reach the examiner by telephone are unsuccessful, the examiner’s supervisor, Frantz Jules can be reached at 5712726681. The fax phone number for the organization where this application or proceeding is assigned is 571-273-8300.
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/BRIAN M KING/ Primary Examiner, Art Unit 3763
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