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 .
Election/Restrictions
REQUIREMENT FOR UNITY OF INVENTION
As provided in 37 CFR 1.475(a), a national stage application shall relate to one invention only or to a group of inventions so linked as to form a single general inventive concept (“requirement of unity of invention”). Where a group of inventions is claimed in a national stage application, the requirement of unity of invention shall be fulfilled only when there is a technical relationship among those inventions involving one or more of the same or corresponding special technical features. The expression “special technical features” shall mean those technical features that define a contribution which each of the claimed inventions, considered as a whole, makes over the prior art.
The determination whether a group of inventions is so linked as to form a single general inventive concept shall be made without regard to whether the inventions are claimed in separate claims or as alternatives within a single claim. See 37 CFR 1.475(e).
When Claims Are Directed to Multiple Categories of Inventions:
As provided in 37 CFR 1.475 (b), a national stage application containing claims to different categories of invention will be considered to have unity of invention if the claims are drawn only to one of the following combinations of categories:
(1) A product and a process specially adapted for the manufacture of said product; or
(2) A product and a process of use of said product; or
(3) A product, a process specially adapted for the manufacture of the said product, and a use of the said product; or
(4) A process and an apparatus or means specifically designed for carrying out the said process; or
(5) A product, a process specially adapted for the manufacture of the said product, and an apparatus or means specifically designed for carrying out the said process.
Otherwise, unity of invention might not be present. See 37 CFR 1.475 (c).
Restriction is required under 35 U.S.C. 121 and 372.
This application contains the following inventions or groups of inventions which are not so linked as to form a single general inventive concept under PCT Rule 13.1.
In accordance with 37 CFR 1.499, applicant is required, in reply to this action, to elect a single invention to which the claims must be restricted.
Group I, claims 13-24, drawn to a facility for refrigerating and liquefying hydrogen to a cryogenic temperature.
Group II, claim 27, a hydrogen refrigeration facility for refrigerating and liquefying hydrogen to a cryogenic temperature.
The groups of inventions listed above do not relate to a single general inventive concept under PCT Rule 13.1 because, under PCT Rule 13.2, they lack the same or corresponding special technical features for the following reasons:
The common features are not special technical feature as they do not make a contribution over the prior art in view of Decker et al. (US 2022/0082210 A1). Decker discloses a hydrogen refrigeration facility configured to refrigerate and liquefy hydrogen to cryogenic temperatures (¶ 0015), the facility including a refrigeration working circuit (20) operating with hydrogen as a cycle gas, the working circuit including compression (110) and expansion (expansion devices 124, 126) of the cycle gas, and an ejector (ejector 146) fluidically connected to the refrigeration circuit and configured to recover boil-off gas (152) from a mobile liquid hydrogen transport tank (28) and introduce the recovered gas into the refrigeration working circuit (see fig. 1).
Applicant is reminded that upon the cancelation of claims to a non-elected invention, the inventorship must be corrected in compliance with 37 CFR 1.48(a) if one or more of the currently named inventors is no longer an inventor of at least one claim remaining in the application. A request to correct inventorship under 37 CFR 1.48(a) must be accompanied by an application data sheet in accordance with 37 CFR 1.76 that identifies each inventor by his or her legal name and by the processing fee required under 37 CFR 1.17(i).
Since applicant has received an action on the merits for the originally presented invention, this invention has been constructively elected by original presentation for prosecution on the merits. Accordingly, claim 27 is withdrawn from consideration as being directed to a non-elected invention. See 37 CFR 1.142(b) and MPEP § 821.03.
Claim Interpretation
The following is a quotation of 35 U.S.C. 112(f):
(f) Element in Claim for a Combination. – An element in a claim for a combination may be expressed as a means or step for performing a specified function without the recital of structure, material, or acts in support thereof, and such claim shall be construed to cover the corresponding structure, material, or acts described in the specification and equivalents thereof.
The following is a quotation of pre-AIA 35 U.S.C. 112, sixth paragraph:
An element in a claim for a combination may be expressed as a means or step for performing a specified function without the recital of structure, material, or acts in support thereof, and such claim shall be construed to cover the corresponding structure, material, or acts described in the specification and equivalents thereof.
This application includes one or more claim limitations that do not use the word “means,” but are nonetheless being interpreted under 35 U.S.C. 112(f) or pre-AIA 35 U.S.C. 112, sixth paragraph, because the claim limitation(s) uses a generic placeholder that is coupled with functional language without reciting sufficient structure to perform the recited function and the generic placeholder is not preceded by a structural modifier. Such claim limitation(s) is/are:
“a member configured to collect a cooled and/or liquefied hydrogen” in claim 13, line 4, is understood to be a storage tank or a liquefied hydrogen transport tank.
“a compression member” in claim 13, line 12, understood to be a compressor.
“a cooling member” in claim 13, line 13, understood to be a heat exchanger.
“a warming member” in claim 13, line 16, understood to be a heat exchanger.
“a pre-cooling member” in claim 16, understood to be a heat exchanger.
Because this/these claim limitation(s) is/are being interpreted under 35 U.S.C. 112(f) or pre-AIA 35 U.S.C. 112, sixth paragraph, it/they is/are being interpreted to cover the corresponding structure described in the specification as performing the claimed function, and equivalents thereof.
If applicant does not intend to have this/these limitation(s) interpreted under 35 U.S.C. 112(f) or pre-AIA 35 U.S.C. 112, sixth paragraph, applicant may: (1) amend the claim limitation(s) to avoid it/them being interpreted under 35 U.S.C. 112(f) or pre-AIA 35 U.S.C. 112, sixth paragraph (e.g., by reciting sufficient structure to perform the claimed function); or (2) present a sufficient showing that the claim limitation(s) recite(s) sufficient structure to perform the claimed function so as to avoid it/them being interpreted under 35 U.S.C. 112(f) or pre-AIA 35 U.S.C. 112, sixth paragraph.
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 19, 22 and 26 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 19 recites the limitation “maintaining the ejector outlet temperature above 24 K to prevent undesirable Joule-Thomson expansion effects in downstream heat exchangers” in line 3-4 introduces a new matter because the limitations encompasses subject matter that is not supported in the original disclosure.
Claim 22 recites the limitation “a set point being dynamically adjusted presence of the at least one mobile tank to maintain suction pressure stability for hydrogen boil-off gas recovery” in line 4-5 introduces a new matter because the limitations encompasses subject matter that is not supported in the original disclosure.
Claim 26 recites the limitation “purifying the boil-off gas after the boil-off gas is injected into the working circuit and before the boil-off gas is compressed by the compression member” introduces a new matter because the limitations encompasses subject matter that is not supported in the original disclosure. In this case, contrary to the claimed scope, applicant’s original disclosure only support for having “the boil-off gas recovered will be purified again when it combines with the feedstock of the facility 1” (see applicant’s publication ¶ 0058).
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 13-26 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 13 recites “a driving-fluid inlet opening is connected, via a first set of pipe(s) and valve(s) to a low-pressure return leg of the working circuit of the circuit of the refrigerator that is downstream of the expansion member and upstream of the compression member” 17-20 renders the claim indefinite because the term “low-pressure” is a relative term which does not have a clear boundary in the claim. The claim does not define what constitutes low pressure, nor does it provide an objective standard for distinguishing a low-pressure return leg from other pressure levels such as intermediate pressure or high pressure within the working circuit. The specification likewise does not provide a clear definition or pressure range that would allow one of ordinary skill in the art to determine the scope of the term with reasonable certainty. Accordingly, the metes and bounds of the claim are unclear and the claim is indefinite. For examination purposes, because the claim fails to define the boundaries of ‘low pressure,’ the limitation reads on any return leg operating at a pressure lower than the pressure of the cycle fluid upstream the expansion member.
Claim 17 recites the limitation "a facility” in line 2 renders the claim indefinite because it is unclear how it relates with the previously cited limitation “a facility” in claim 13, line 1.
Claim 17 recites the limitation "the suction intake” in line 4 lacks proper antecedent basis.
Claim 17 recites the limitation "the outlet stream from the ejector” in line 5 lacks antecedent basis.
Claim 19 recites the limitation "the pressure of the driving fluid” and “the pressure of the boil-off gas” in line 2 lacks proper antecedent basis.
Claim 19 recites the limitation “outlet stream” in line 3 renders the claim indefinite because it is unclear how it relates with the previously cited limitation “the outlet stream” in line 5 of claim 17.
Claim 21 is amended to cancel all the limitations of the claim, however, the status of the claim is marked as “Currently Amended” instead of “Canceled”. Appropriate correction required.
Claim 22 recites the limitation “a set point” in line 4 renders the claim indefinite because it is unclear if it is referring to the previously cited limitation “a constant pressure set point” or entirely a different set point.
Claim 24 recites the limitation "the ejectors” in line 4 lacks proper antecedent basis. Appropriate correction required in the rest of the claim limitations wherein “the ejectors” is mentioned. Should read –the rejector--.
Claim 24 recites the limitation "pressurized working gas” in line 5 renders the claim indefinite because it is unclear how it relates with the previously cited limitation “pressurized working gas” in claim 17.
Claim 24 recites the limitation "the outlet streams” in line 4 lacks proper antecedent basis. Or should read –the outlet stream—to be consistent with the limitations of claim 17.
Claim 25 recites the limitations “the pressure” and "the boil-off gas” in line 2 lacks proper antecedent basis.
Claims 14-18, 20, 23 and 26 are also rejected under 35 U.S.C. 112(b) for being dependent on 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.
Claim(s) 13-21 and 23-26 are rejected under 35 U.S.C. 103 as being unpatentable over Decker et al. (US 2022/0082210 A1) in view of Delahunty (US 3,800,550).
In regard to claim 13, Decker teaches a facility for refrigerating and liquefying hydrogen to a cryogenic temperature (¶ 0015), the facility comprising:
a circuit (the hydrogen flowline in liquefying unit 10) configured to cool hydrogen, the circuit comprising an upstream end (upstream end wherein feed gas stream 12 is introduced) configured to be connected to a hydrogen source (14) and a downstream end connected to a member (storage tank 18 and transport tanks 28) configured to collect a cooled and/or liquefied hydrogen (¶ 0056, 0058; fig. 1);
a set of heat exchanger(s) (heat exchangers 74, 80, 82, 84, 92) in a heat exchange relationship with the circuit for hydrogen (12) that is to be cooled (see fig. 1);
a cooling device (cooling system 20) in a heat exchange relationship with the set of heat exchanger(s) (see fig. 1), said cooling device comprising a refrigerator (heat exchanger 166, heat exchanger 166, expansion devices 124, 126, 148) performing a refrigeration cycle on a cycle gas (hydrogen gas 100 from transport tanks 28 and hydrogen gas 102 from storage tank 18 forming cycle gas 160) in a working circuit (cooling cycle 24), the cycle gas being hydrogen (see fig. 1; ¶ 0089), the working circuit of the refrigerator comprising:
a compression member (compressor system 110) configured to compress the cycle gas (158) (see fig. 1),
a cooling member (expansion devices 124, 126 and/or heat exchangers 74, 80, 82, 84, 92) configured to cool the cycle gas (see fig. 1; ¶ 0082-0083),
an expansion member (an expansion device 148 comprising a throttle valve and an expansion turbine) configured to expand the cycle gas comprising at least one turbine (¶ 0085), and
a warming member configured to warm the cycle gas (heat exchangers 74, 80, 82, 84, 92); and
the facility comprising at least an ejector (146) of which a driving-fluid (150) inlet opening (a point wherein fluid 150 enter ejector 146) is connected, via a first set of pipe(s) and valve(s) (see pipe 138 and comprising a valve on pipeline 138, see fig. 1) to a low-pressure return leg (160) of the working circuit (24) of the refrigerator that is downstream of the expansion member (expansion device 148) and upstream of the compression member (110) (see fig. 1; ¶ 0088, 0090-0091, wherein the ejector 146 disposed downstream the expansion member 148 on the low-pressure return leg 160 of the circuit), an intake of the ejector (146) being connected to a second set of pipe (s) equipped with valve(s) (see pipe 100/156/152 equipped with valve 154) having an end (the end point of line 152) configured to be connected to a gas overhead (stream 100 connected to the overhead line 38 of transport tanks 28, see fig. 1) of at least one mobile tank (28) configured to transport liquefied hydrogen (see fig. 1),
wherein the at least one mobile tank (28) comprises a liquefied hydrogen transport tank (28) configured to be filled with liquid hydrogen (36) by a downstream end of a hydrogen circuit (16) (see fig. 1; ¶ 0058-0059),
Decker teaches wherein an outlet of the ejector (146) being connected, via a third a pipe (158) to the working circuit (160/24) of the refrigerator (see fig. 1) at a point downstream the expansion member (an expansion device 148) and upstream the warming member (see fig. 1; e.g., heat exchanger 80, 82), but does not explicitly teach the outlet of the ejector being connected via a valve to the working circuit of the refrigerator.
However, Delahunty teaches a liquefaction system comprising an ejector system (25, 37), wherein the ejector system comprises valves (42 and 46) on an outlet pipes of the ejectors (25, 37) (see fig. 1), wherein whenever the ejectors are out of use, the valves (42 and 46) can be closed (see col. 4, lines 29-39).
Therefore, it would have been obvious to a person having ordinary skill in the art before the effective filing date of the claimed invention, to modify the facility of Decker by providing a valve on the outlet of the ejector, based on the teachings of Delahunty, in order to regulate the ejector discharge pressure and flow to stabilize operation, optimize performance under varying load, and prevent undesirable backflow or over pressurization, and provide operational flexibility. Such modifications constitute nothing more than the predictable use of known elements (i.e., a valve on an ejector outlet) to achieve predictable results (improve control, stability, and safety of the working circuit).
In regard to claim 14, Decker teaches the facility as claimed in Claim 13, further comprising several ejectors (ejector 88 and 146) (see fig. 1).
In regard to claim 15, Decker teaches the facility as claimed in Claim 13, wherein the at least one mobile tank (28) further comprises a fluid inlet (the inlet of line 36 to tank 28) configured to be connected removably to the downstream end of the hydrogen circuit (16) such that the at least one mobile tank (28) is configured to be filled with cooled hydrogen (via line 36) (see fig. 1), the at least one mobile tank (28) further comprising a boil-off gas outlet (38) configured to be connected removably (via valve 98) to a suction intake of the ejector (146) via the second set of pipe (152) equipped with valve (154) (see fig. 1, ¶ 0058). Decker teaches a docking station 30 that comprises the at least one tank (28) is removably connected with hydrogen circuit.
In regard to claim 16, Decker teaches the facility as claimed in Claim 13, wherein the cooling device comprises a pre-cooling member (precooling cold-box 106) in the heat exchange relationship with part of the set of heat exchanger(s) (with heat exchanger 74) (see fig. 1; ¶ 0079-0081, 0093).
In regard to claim 17, Decker teaches a method for liquefying hydrogen using the facility in accordance with Claim 13, the method comprising a step of drawing boil-off gas (38) from the at least one mobile tank (28) into the suction intake (via 100/156/152) of the ejector (146) using, as the driving fluid (138/150) for the ejector (146), pressurized working gas from the working circuit, the outlet stream (158) from the ejector (146) being injected into the working circuit (160/24) (see fig. 1; ¶ 0085, 0087, 0088).
In regard to claim 18, Decker teaches the method as claimed in Claim 17, wherein the boil-off gas sucked up is at a pressure of between 1.01325 and 1.5 bara (a pressure of 10 bar or less) and at a temperature of between the saturation temperature of the hydrogen (i.e., ≈20.28 K) and 60K (at a temperature of 31 K) (¶ 0018-0019, 0061).
In regard to claim 19, Decker teaches the method as claimed in Claim 17, wherein Decker teaches a pressure of the driving fluid (138/150) and a pressure of the boil-off gas (38) combined in the ejector, but does note explicitly teach result in an outlet stream pressure of 1.25 to 2 bara and (maintaining the ejector outlet temperature above 24K to prevent undesirable Joule-Thomson expansion effects in downstream heat exchangers: see the 112(a) rejection above regarding the limitation). However, the selection of particular pressure and temperature conditions for the driving fluid would have been an obvious matter of routine optimization to one of ordinary skill in the art. The pressure and temperature of the driving fluid are recognized in the art as result-effective variables because they directly affect ejector performance, including entrainment ratio, efficiency, and refrigeration capacity. It would have been obvious to a person of ordinary skill in the art, motivated by the desire to optimize ejector operation, to adjust the pressure and temperature of the driving fluid within values that achieve stable operation and improved performance. As set forth in In re Aller, 220 F.2d 454 (CCPA 1955), and In re Peterson, 315 F.3d 1325 (Fed. Cir. 2003), the discovery of an optimum or workable range by routine experimentation within a known broader range does not constitute patentable invention when the parameter is recognized as a result-effective variable. Accordingly, it would have been obvious to a person having ordinary skill in the art before the effective filing date of the claimed invention, to modify the outlet stream pressure to 1.25 to 2 bara by optimizing the driving fluid and the boil-off pressure as a matter of routine engineering to achieve the predictable result of a desired ejector output pressure.
In regard to claim 20, Decker teaches the method as claimed in Claim 17, wherein the outlet stream (158) leaving the ejector (146) is at a pressure greater than or equal to a pressure of the cycle gas (160) at a coldest point in the working circuit (24) (see fig. 1; ¶ 0085, 0088, 0091).
In regard to claim 21, (see 112(b) rejection above. The claim is entirely canceled.
In regard to claim 23, Decker teaches the method as claimed in Claim 17, wherein the outlet stream (158) from the ejector (146) being is injected into the working circuit (160/24) at the cold end of the working circuit (see Decker fig. 1).
In regard to claim 24, Decker teaches the method as claimed in Claim 17, wherein during the step of drawing boil-off gas (156) from the at least one mobile tank (28), the driving fluid (138/150) for the ejectors (146) pressurized working gas from the working circuit (160/24), and wherein the outlet streams (158) from the ejectors (146) are then injected into the working circuit (160) (see fig. 1; ¶ 0085-0087-0088).
In regard to claim 25, Decker teaches the facility as claimed in Claim 13, wherein the ejector (146) is configured to increase a pressure of the boil-off gas (156) to a level greater than or equal to a pressure of the low-pressure return leg (160) of the working circuit (24) upstream of the warming member (e.g., heat exchanger 80, 82) (see fig. 1; ¶ 0085-0086, 0088, 0091).
In regard to claim 26, Decker teaches the method as claimed in Claim 17, but does not explicitly teach purifying the boil-off gas after the boil-off gas is injected into the working circuit and before the boil-off gas is compressed by the compression member. However, Official Notice is taken that purifying a recycle boil-off gas is a conventional or well-known feature or method to remove impurities. Therefore, it would have been obvious to a person having ordinary skill in the art before the effective filing date of the claimed invention, to modify the process of Decker by purifying the recovered boil-off gas, in order to improve liquefaction efficiency, protect equipment, prevent freezing/blockage, avoids impurity buildup, and ensures safety and product purity.
Claim(s) 22 is rejected under 35 U.S.C. 103 as being unpatentable over Decker and Delahunty as applied to claim 17 above, and further in view of Beg et al. (US 20150338097 A1).
In regard to claim 22, Decker teaches the method as claimed in Claim 17, but does not explicitly teach the flowrate of the driving fluid is controlled as a function of an outlet pressure of the ejector, said flowrate being regulated to maintain a constant pressure set point at the outlet of the ejector. The amended claim limitation “a set point being dynamically adjusted presence of the at least one mobile tank to maintain suction pressure stability for hydrogen boil-off gas recovery” is a new matter (see the 112a rejection above).
However, Beg teaches an apparatus and method for controlling a flow of a fluid in an ejector, wherein Beg teaches a control system comprising the control unit (28) and a control lines (29) sends control signals to the LP flow control valves (3,4) whereby the second LP flow control valve (3) opens, followed by the first LP flow control valve (4) closing. Substantially simultaneously, control system causes the first HP flow control valve (2) to open to feed HP gas to the HP inlet (6b) of the jet pump (6). Pressure transmitter (11) measures the pressure of the LP gas in the second LP flow line (20), under influence of the pressure drop generated by operation of the jet pump (6). This pressure reading is transmitted to the control unit (28), which adjusts the setting of the first HP flow control valve (2) to control the amount of HP gas delivered to the jet pump (6), according to the detected LP gas flow rate (see ¶ 0074-0075; fig. 1).
Therefore, it would have been obvious to a person having ordinary skill in the art before the effective filing date of the claimed invention, to modify the process of Decker by controlling the flowrate of the driving fluid as a function of the outlet pressure of the ejector to maintain a constant pressure set point, based on the teachings of Beg, in order to maintain stable outlet conditions, since ejectors are pressure-driven devices and fluctuations in outlet pressure can adversely affect downstream equipment because maintaining a constant pressure is a routine engineering goal for system stability and reliability, and a person of ordinary skill would have recognized that regulating flow based on outlet pressure prevents harmful pressure surges or drops that could damage or reduce the efficiency of the downstream working circuit.
Response to Arguments
Applicant’s arguments with respect to the amended claims have been considered but are moot because of the new ground(s) of rejection, unless otherwise noted below.
Applicant argues that the combination of Decker (US 2022/0082210 A1) and Delahunty (US 3,800,550) does not teach or suggest connecting the ejector driving-fluid inlet to a low-pressure return leg downstream of the expansion member and upstream of the compressor. Applicant further contends that Decker allegedly utilizes an intermediate-pressure stream rather than the low-pressure return leg, and that the architecture and function of the ejector differs from that recited in claim 13.
These arguments are not persuasive. First, Decker explicitly discloses an ejector 146 disposed on the recirculation line 160 of the refrigeration cycle, which corresponds to the low-pressure return portion of the working circuit downstream of the expansion device and upstream of the compressor system. Decker explains that the ejector is positioned on the return path of the refrigeration cycle gas that ultimately returns to compressor system 110 after passing through the heat exchanger system. Thus, Decker clearly teaches integration of the ejector with the low-pressure side of the refrigeration circuit. Applicant’s characterization that Decker exclusively uses an “intermediate-pressure” stream does not overcome the rejection because the claim merely requires a connection to a low-pressure return leg relative to the refrigeration cycle, not a specific absolute pressure value. As explained in the rejection, for examination purposes the claimed “low-pressure return leg” reasonably reads on any return stream operating at a pressure lower than the high-pressure portion upstream of the expansion member. The stream utilized in Decker for driving the ejector originates from the refrigeration cycle and therefore constitutes a working-fluid stream within the same circuit. Furthermore, the rejection does not rely solely on Decker for the presence of a valve at the ejector outlet. Delahunty explicitly teaches providing valves on ejector outlet lines in liquefaction systems to regulate operation and isolate the ejector when not in use (col. 4, lines 29-39). It would have been obvious to a person of ordinary skill in the art to incorporate such valves into the Decker system in order to regulate ejector discharge pressure and flow, prevent backflow, and improve operational flexibility. The modification merely applies a known control element to a known ejector configuration to achieve predictable results.
Applicant’s argument regarding the alleged recovery of “cold energy” or specific placement within the cold end of the heat exchanger train is also unpersuasive because claim 13 does not require such a thermodynamic objective or functional advantage. The claim only recites structural relationships within the working circuit, which are taught by Decker as discussed above.
Applicant additionally argues that Decker’s ejector performs a different function because it compresses a partial refrigerant stream and hydrogen rather than primarily processing boil-off gas from a mobile tank.
This argument is not persuasive. Decker expressly discloses that the ejector intake receives hydrogen gas originating from the overhead of mobile transport tanks during loading operations. Thus, the ejector is already configured to draw vapor originating from mobile tanks and mix that stream with working-cycle gas. The fact that Decker also processes additional hydrogen streams does not negate the disclosure of recovering boil-off gas from transport tanks. It is well established that a prior art reference need not be identical in purpose or motivation to render a claim obvious. The relevant inquiry is whether the structural arrangement and operation would have been obvious to a person of ordinary skill in the art. Decker already teaches the relevant structural configuration of an ejector integrated with a hydrogen liquefaction cycle and connected to mobile transport tank vapor lines. The addition of outlet control valves from Delahunty merely improves operational control of the ejector. Applicant’s assertion that the present system represents a “novel and synergistic integration” is unsupported by objective evidence and does not overcome the clear teachings of the prior art.
Applicant further argues (Remark page 10, regarding claim 22) that Beg (US 2015/0338097 A1) allegedly teaches only a general ejector control scheme in the context of hydrocarbon flare systems and does not disclose dynamically adjusting a set point based on the presence of a mobile tank.
These arguments are not persuasive. Beg clearly teaches a control system in which: a pressure transmitter measures pressure associated with the ejector, and a control unit adjusts the motive-fluid flow rate through a control valve based on the detected pressure in order to maintain desired operating conditions. This disclosure demonstrates the general and well-known principle of controlling ejector operation by regulating motive-fluid flow as a function of system pressure. Applying such a control strategy to the ejector arrangement of Decker would have been well within the routine skill of an engineer designing a cryogenic liquefaction facility. Applicant’s additional limitation concerning a “set point being dynamically adjusted based on the detected presence of the mobile tank” does not render the combination non-obvious. The presence or absence of a mobile tank is simply an operational condition that affects vapor generation and system pressure. A person of ordinary skill in the art would have recognized that ejector control parameters, including pressure set points, may be adjusted depending on operating conditions such as whether boil-off gas from a mobile tank is present during filling operations. Such adaptive control constitutes a routine implementation of process control logic once pressure-based control of the ejector is known. Moreover, as indicated in the rejection under 35 U.S.C. 112(a), the claimed limitation regarding dynamic adjustment based on the presence of the mobile tank lacks clear support in the originally filed specification. Therefore, even if considered, the amendment does not overcome the obviousness rejection.
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 WEBESHET MENGESHA whose telephone number is (571)270-1793. The examiner can normally be reached Mon-Thurs 7-4, alternate Fridays, EST. 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, Frantz Jules can be reached at 571-272-6681. The fax phone number for the organization where this application or proceeding is assigned is 571-273-8300. Information regarding the status of published or unpublished applications may be obtained from Patent Center. Unpublished application information in Patent Center is available to registered users. To file and manage patent submissions in Patent Center, visit: https://patentcenter.uspto.gov. Visit https://www.uspto.gov/patents/apply/patent-center for more information about Patent Center and https://www.uspto.gov/patents/docx for information about filing in DOCX format. For additional questions, contact the Electronic Business Center (EBC) at 866-217-9197 (toll-free). If you would like assistance from a USPTO Customer Service Representative, call 800-786-9199 (IN USA OR CANADA) or 571-272-1000.
/W.M/Examiner, Art Unit 3763
/FRANTZ F JULES/Supervisory Patent Examiner, Art Unit 3763