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 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 8-10, 12-17 and 19-23 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.
Claims 8 and 15 recite that the second stream is “the second stream contains mercury, wherein the second stream is incompatible with processing by the first exchanger.” This limitation is indefinite because the claims do not set forth any objective standard by which one of ordinary skill in the art could determine the boundary of “incompatible.” “Incompatible” is a relative, comparative term, and its scope is not reasonably ascertainable from the claim language alone, since the claim does not recite any threshold mercury content, pressure, temperature, material-degradation criterion, or other measurable property that would distinguish a stream that is “incompatible” from one that is merely less efficiently processed by the first exchanger.
The specification likewise does not provide an objective standard for this term. Paragraph [0065] of the as-filed specification states only that streams may include “contaminants, such as mercury content and the like, that may not all be compatible with a single exchanger configuration,” and that this allows “non-compatible streams, e.g., streams containing amounts of mercury that exceed desirable levels or are at pressures and temperatures that are less compatible with PCHE and BAHX technology, to pass through the same vessel.” This passage uses the same relative terms (“not all be compatible,” “desirable levels,” “less compatible”) that appear in the claim, without providing any numerical threshold (e.g., a mercury concentration in ppt, ppb, µg/Nm3, or similar units), reference to an industry standard, or other objective metric by which a person of ordinary skill in the art could determine when a stream crosses from “compatible” to “incompatible” with the first exchanger. Because neither the claims nor the specification supplies a standard for measuring the degree of incompatibility required, the metes and bounds of this limitation cannot be determined with reasonable certainty. See MPEP § 2173.05(b) (relative and subjective terminology, such as terms of degree, render a claim indefinite where the specification provides no standard for ascertaining the requisite degree).
For purposes of applying the prior art below, and consistent with MPEP § 2173.06, this term is given the broadest reasonable interpretation supported by the specification: a stream containing mercury in an amount that would be expected to cause mercury-related damage (e.g., liquid metal embrittlement, amalgam corrosion, or solid-mercury deposition/plugging) if processed through a brazed aluminum exchanger. The prior art applied below is shown to teach this limitation under that interpretation, rather than being treated as non-limiting intended-use language.
Claims 9, 10, 12-14, 16, 17, 19-23 are also rejected under 35 U.S.C. 112(b) for 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.
Claim(s) 8-10, 12-14 and 22 are rejected under 35 U.S.C. 103 as being unpatentable over Low et al. (US 5,651,270) in view of Minton et al. (US 2006/0242969 A1), and further in view of Briglia et al. (US 9,950,274 B2).
In regard to claim 8, Low teaches a hybrid core-in-shell heat exchanger comprising:
a vessel (40) including an interior portion (inside of vessel 40) configured to receive a liquid refrigerant (54) (col. 3, ln. 30-43; fig. 1, 2);
a first exchanger having a first exchanger configuration (42) arranged in the liquid refrigerant (54) of the interior portion of the vessel (40), the first heat exchanger (42) being a brazed aluminum heat exchanger (BAHX) (col. 3, ln. 47-51: Low discloses a plate-fin core heat exchanger, which is another commonly known name for a brazed aluminum heat exchanger) comprising a first inlet (where the feed gas stream (20) enters HX 42) receiving a first stream (20) of a first parameter (see Table 1, stream 20; e.g., pressure, composition, and flowrate) (fig. 1, 2); and
a second exchanger having a second exchanger configuration (44) arranged in the liquid refrigerant (54) of the interior portion of the vessel (40), the second exchanger (44) comprising a second inlet (where the ethylene stream (31) enters HX 44) receiving a second stream (31) (col. 3, ln. 47-51; fig. 1, 2);
Low further teaches that the first stream (20) and the second stream (31) are fluidically isolated from each other within the interior portion of the vessel (40) while in temperature communication with the liquid refrigerant (54) of the interior portion of the vessel (40) (fig. 1, 2).
Low teaches the first and second exchangers as brazed aluminum heat exchangers (plate-fin cores), but does not explicitly teach the second exchanger to be a tube bundle exchanger. However, Minton teaches a heat exchanger (10) comprising a vessel (12) including an interior portion, wherein first (18) and second (18) exchangers are arranged in the interior portion, and wherein either or both of the first and second heat exchangers could be a tube bundle exchanger, a printed circuit heat exchanger, a core-in-kettle heat exchanger, or other suitable configuration (¶ 0014-0015; fig. 1). In this case, Minton teaches that tube bundle exchangers and printed circuit heat exchangers are known, interchangeable alternatives for use within a common refrigerant vessel.
Therefore, it would have been obvious to one of ordinary skill in the art, before the effective filing date of the claimed invention, to modify Low by substituting the second brazed aluminum heat exchanger (plate-fin core) of Low with a tube bundle exchanger, in view of the teachings of Minton, for the purpose of providing a heat exchanger configuration suitable for a high-pressure or otherwise less-compatible fluid, that is easy to maintain and versatile for use across a variety of process streams. Furthermore, tube bundles, plate-fin cores, and printed circuit heat exchangers are recognized interchangeable options in the art; replacing one known exchanger with another would have been an obvious matter of routine engineering design.
The modified Low, as combined above, do not explicitly teach that the second stream contains mercury or that the second stream is incompatible with processing by the first exchanger (as that term is interpreted above under the broadest reasonable interpretation, i.e., a mercury-laden stream that would cause mercury-related damage if processed through a brazed aluminum exchanger). However, Briglia teaches that the presence of mercury in a stream processed by a brazed aluminum exchanger causes liquid metal embrittlement (LME), in which liquid mercury amalgamates with the aluminum and pierces the exchanger (col. 1, ln. 42-46), and that solidified mercury deposited in an aluminum exchanger leads to plugging and embrittlement during shutdown phases (col. 1, ln. 37-40). Briglia further teaches that, for the portion of a cooling process colder than approximately -38.6°C, continued use of a brazed aluminum exchanger “would be inoperative” because the mercury “would be deposited in solid form... on the walls” (col. 2, ln. 36-44), and that “another approach” for that colder portion of the process “is provided that consists in changing materials and/or type of exchanger for the exchanger operating at lower temperature,” wherein “stainless steel becomes suitable because it withstands low temperatures well,” including, for example, a “‘shell and tube’ exchanger, well suited for exchanges between two fluids” (col. 2, ln. 47-58). Briglia's working embodiment confirms this teaching with reference numerals: a mixture is cooled in a first exchanger (9) that is a brazed aluminum plate-fin exchanger, and the resulting gas is sent to a second exchanger (35) that “may be a shell and tube exchanger... made of a metal other than aluminum,” in which “the mercury is deposited in solid form in the second exchanger” (col. 8, ln. 40-52). Claim 1 and claim 12 of Briglia likewise claim a process and apparatus, respectively, in which a mercury-containing flow is cooled in a first brazed aluminum exchanger and then in a second exchanger of stainless steel, copper, nickel, tantalum, or an alloy thereof, the second exchanger being a shell and tube exchanger, a brazed plate-fin exchanger, or a plate and shell exchanger (col. 9, ln. 35-53; col. 10, ln. 30-53). Briglia thus teaches a mercury-containing stream that is incompatible with continued processing by a brazed aluminum exchanger, under the broadest reasonable interpretation of that term set forth above, and teaches routing that stream to a tube-and-shell (tube bundle) exchanger of a different, non-aluminum material specifically because of that incompatibility.
Therefore, 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 modified Low such that the second stream directed to the tube bundle exchanger (44, as modified by Minton) is a mercury-containing stream that is incompatible with processing by the first, brazed-aluminum exchanger (42), in view of the teachings of Briglia, for the purpose of avoiding liquid metal embrittlement, amalgam corrosion, and mercury deposition/plugging that would otherwise occur if a mercury-laden stream were processed in the brazed aluminum first exchanger, while still obtaining indirect heat exchange with the common liquid refrigerant pool of the vessel as already taught by Low and Minton. This combination amounts to using a known technique (routing a mercury-incompatible stream to a tube-and-shell/tube-bundle exchanger of a different material, per Briglia) to improve a similar device (a hybrid, multi-core-in-shell exchanger arrangement, per Low/Minton) in the same way, with predictable results. See KSR Int'l Co. v. Teleflex Inc., 550 U.S. 398.
In regard to claim 9, Low teaches the hybrid core-in-shell heat exchanger according to claim 8, further comprising: a third exchanger having a third exchanger configuration (46) arranged in the interior portion, the third exchanger (46) comprising an inlet (where the methane stream (41) enters HX 46) receiving a third stream (41), the third stream being fluidically isolated from the first stream (20) and second stream (31) (fig. 1, 2).
In regard to claim 10, Low teaches the hybrid core-in-shell heat exchanger according to claim 9, wherein the third exchanger (46) configuration is distinct (heat exchanger 46 has a distinct fluid flow and a distinct position in the vessel from heat exchangers 42 and 44) from the first (42) and second exchanger (44) configurations (fig. 1, 2).
In regard to claim 12, Low teaches the hybrid core-in-shell heat exchanger according to claim 8, further comprising: an amount of liquid refrigerant (54) contained in the interior portion of the vessel, the amount of liquid refrigerant (54) having a surface portion (level 52, 53), wherein at least one of the first (42) and second exchangers (44) includes a section that projects above the surface portion (fig. 1, 2).
In regard to claim 13, Low teaches at least one of the first (42) and second exchangers (44) includes a section that projects above the surface portion (fig. 1, 2), but does not explicitly teach that the section projects at least 4 inches (10.1 cm) above the surface portion. However, the projection of the sections of the first and second exchangers is a variable that can be modified by adjusting the amount of refrigerant level in the vessel, with the projection of the sections of the heat exchangers increasing as the refrigerant level decreases and vice versa, and the precise length of the projection would have been recognized as a result-effective variable by one of ordinary skill in the art before the effective filing date of the invention. Absent a showing of unexpected results, the claimed length cannot be considered critical. Accordingly, it would have been obvious to one of ordinary skill in the art to optimize, through routine experimentation, the projection of the heat exchanger sections by adjusting the refrigerant level in the vessel of Low to obtain the desired heat transfer balance between the exchangers and the refrigerant. See In re Aller, 220 F.2d 454, 456, 105 USPQ 233, 235 (CCPA 1955); In re Boesch, 205 USPQ 215 (CCPA 1980) (see MPEP § 2144.05, II).
In regard to claim 14, Low teaches the hybrid core-in-shell heat exchanger according to claim 8, wherein the hybrid core-in-shell heat exchanger forms part of a liquid natural gas (LNG) production (col. 6, ln. 1-6; fig. 1).
In regard to claim 22, Low teaches the hybrid core-in-shell heat exchanger according to claim 8, wherein the first parameter of the first stream (20) and a second parameter of the second stream (31) each comprises a temperature or a pressure (see Table 1, streams 20 and 31).
Claim(s) 15-17, 19-21 and 23 are rejected under 35 U.S.C. 103 as being unpatentable over Low et al. (US 5,651,270) in view of Eaton et al. (US 2006/0086140 A1) in view of Minton et al. (US 2006/0242969 A1), and further in view of Briglia et al. (US 9,950,274 B2).
In regard to claim 15, Low teaches a system comprising:
a compressor (the multistage compressor not separately shown but inherent to the propane/ethylene/methane refrigeration cycle of Low) and
a hybrid core-in-shell heat exchanger (40) comprising a vessel (40) including an interior portion (inside of vessel 40) configured to receive a liquid refrigerant (54) (col. 3, ln. 30-43; fig. 1, 2);
a first exchanger having a first exchanger configuration (42) arranged in the liquid refrigerant (54) of the interior portion of the vessel (40), the first heat exchanger (42) being a brazed aluminum heat exchanger (BAHX) (col. 3, ln. 47-51: Low discloses a plate-fin core heat exchanger, which is another commonly known name for a brazed aluminum heat exchanger) comprising a first inlet (where the feed gas stream (20) enters HX 42) receiving a first stream (20) of a first parameter (see Table 1, stream 20; e.g., pressure, composition, and flowrate) (fig. 1, 2); and
a second exchanger having a second exchanger configuration (44) arranged in the liquid refrigerant (54) of the interior portion of the vessel (40), the second exchanger (44) comprising a second inlet (where the ethylene stream (31) enters HX 44) receiving a second stream (31) (col. 3, ln. 47-51; fig. 1, 2), wherein the first stream (20) and the second stream (31) are fluidically isolated from each other within the interior portion of the vessel (40) while in temperature communication with the liquid refrigerant (54) of the interior portion of the vessel (40) (fig. 1, 2).
Low teaches a natural gas stream cooled in a hybrid core-in-shell heat exchanger (40), but does not explicitly teach the system comprising a cooler receiving natural gas from the compressor and connected to the hybrid core-in-shell heat exchanger.
However, Eaton teaches a natural gas liquefaction system for transferring heat from a refrigerant to natural gas, wherein a portion of a natural gas stream (628, 640, 648) compressed in a methane gas compressor (583) is cooled in a cooler (586) and routed to a high-pressure propane chiller (502: a hybrid core-in-kettle heat exchanger having three separate cores) for further cooling (¶ 0074, 0078; fig. 10). Therefore, it would have been obvious to one of ordinary skill in the art, before the effective filing date of the claimed invention, to modify the system of Low by providing a cooler receiving natural gas from a compressor and connecting the cooler to the hybrid core-in-shell heat exchanger, in view of the teachings of Eaton, in order to reduce the temperature of the compressed natural gas and optimize the refrigeration cycle to produce a condensed natural gas product before the natural gas enters the hybrid core-in-shell heat exchanger.
Low teaches the first and second exchangers as brazed aluminum heat exchangers (plate-fin cores), but does not explicitly teach the second exchanger to be a tube bundle exchanger.
However, Minton teaches a heat exchanger (10) comprising a vessel (12) including an interior portion, wherein first (18) and second (18) exchangers are arranged in the interior portion, and wherein either or both of the first and second heat exchangers could be a tube bundle exchanger, a printed circuit heat exchanger, a core-in-kettle heat exchanger, or other suitable configuration (¶ 0014-0015; fig. 1). In this case, Minton teaches that tube bundle exchangers and printed circuit heat exchangers are known, interchangeable alternatives for use within a common refrigerant vessel. Therefore, it would have been obvious to one of ordinary skill in the art, before the effective filing date of the claimed invention, to modify Low by substituting the second brazed aluminum heat exchanger (plate-fin core) of Low with a tube bundle exchanger, in view of the teachings of Minton, for the purpose of providing a heat exchanger configuration suitable for a high-pressure or otherwise less-compatible fluid, that is easy to maintain and versatile for use across a variety of process streams. Furthermore, tube bundles, plate-fin cores, and printed circuit heat exchangers are recognized interchangeable options in the art; replacing one known exchanger with another would have been an obvious matter of routine engineering design.
The modified Low, as combined above, do not explicitly teach that the second stream contains mercury or that the second stream is incompatible with processing by the first exchanger (as that term is interpreted above under the broadest reasonable interpretation, i.e., a mercury-laden stream that would cause mercury-related damage if processed through a brazed aluminum exchanger).
However, Briglia teaches that the presence of mercury in a stream processed by a brazed aluminum exchanger causes liquid metal embrittlement (LME), in which liquid mercury amalgamates with the aluminum and pierces the exchanger (col. 1, ln. 42-46), and that solidified mercury deposited in an aluminum exchanger leads to plugging and embrittlement during shutdown phases (col. 1, ln. 37-40). Briglia further teaches that, for the portion of a cooling process colder than approximately -38.6°C, continued use of a brazed aluminum exchanger “would be inoperative” because the mercury “would be deposited in solid form... on the walls” (col. 2, ln. 36-44), and that “another approach” for that colder portion of the process “is provided that consists in changing materials and/or type of exchanger for the exchanger operating at lower temperature,” wherein “stainless steel becomes suitable because it withstands low temperatures well,” including, for example, a “‘shell and tube’ exchanger, well suited for exchanges between two fluids” (col. 2, ln. 47-58). Briglia's working embodiment confirms this teaching with reference numerals: a mixture is cooled in a first exchanger (9) that is a brazed aluminum plate-fin exchanger, and the resulting gas is sent to a second exchanger (35) that “may be a shell and tube exchanger... made of a metal other than aluminum,” in which “the mercury is deposited in solid form in the second exchanger” (col. 8, ln. 40-52). Claim 1 and claim 12 of Briglia likewise claim a process and apparatus, respectively, in which a mercury-containing flow is cooled in a first brazed aluminum exchanger and then in a second exchanger of stainless steel, copper, nickel, tantalum, or an alloy thereof, the second exchanger being a shell and tube exchanger, a brazed plate-fin exchanger, or a plate and shell exchanger (col. 9, ln. 35-53; col. 10, ln. 30-53). Briglia thus teaches a mercury-containing stream that is incompatible with continued processing by a brazed aluminum exchanger, under the broadest reasonable interpretation of that term set forth above, and teaches routing that stream to a tube-and-shell (tube bundle) exchanger of a different, non-aluminum material specifically because of that incompatibility.
Therefore, 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 Low/Eaton/Minton combination such that the second stream directed to the tube bundle exchanger (44, as modified by Minton) is a mercury-containing stream that is incompatible with processing by the first, brazed-aluminum exchanger (42), in view of the teachings of Briglia, for the purpose of avoiding liquid metal embrittlement, amalgam corrosion, and mercury deposition/plugging that would otherwise occur if a mercury-laden stream were processed in the brazed aluminum first exchanger, while still obtaining indirect heat exchange with the common liquid refrigerant pool of the vessel as already taught by Low and Minton. This combination amounts to using a known technique (routing a mercury-incompatible stream to a tube-and-shell/tube-bundle exchanger of a different material, per Briglia) to improve a similar device (a hybrid, multi-core-in-shell exchanger arrangement, per Low/Minton) in the same way, with predictable results. See KSR Int'l Co. v. Teleflex Inc., 550 U.S. 398.
In regard to claim 16, Low teaches the system of claim 15, wherein the hybrid core-in-shell heat exchanger further comprises a third exchanger (46) comprising an inlet receiving a third stream (41) that is fluidically isolated from the first stream (20) and second stream (31) (fig. 1, 2).
In regard to claim 17, Low teaches the system of claim 16, wherein the third exchanger (46) configuration is distinct from the first (42) and second exchanger (44) configurations, for the reasons set forth above in the rejection of claim 10.
In regard to claim 19, Low teaches the system of claim 15, wherein the hybrid core-in-shell heat exchanger further comprises an amount of liquid refrigerant having a surface portion (level 52, 53), wherein at least one of the first (42) and second exchangers (44) includes a section that projects above the surface portion (fig. 1, 2).
In regard to claim 20, Low teaches the system of claim 19, wherein Low teaches at least one of the first (42) and second exchangers (44) includes a section that projects above the surface portion (see the section of the heat exchangers 42 and 44 projected above the refrigerant level 52) (fig. 1, 2), but does not explicitly teach that the section of the one of the first and second exchangers projects at least 4 inches (10.1 cm) above the surface portion. However, the projection of the sections of the first and second exchangers is a variable that can be modified by use, by adjusting the amount of refrigerant level in the vessel, with the projection of the sections of the heat exchangers increasing as the refrigerant level decreases, and vice versa, and the precise length of the section of the heat exchangers' projection would have been considered a result-effective variable by one of ordinary skill in the art before the effective filing date of the invention. As such, absent a showing of unexpected results, the claimed length of the section of the heat exchangers' projection cannot be considered critical. Accordingly, one of ordinary skill in the art before the effective filing date of the invention would have optimized, by routine experimentation, the section of the heat exchangers' projection by adjusting the refrigerant level in the vessel of Low to obtain the desired heat transfer balance between the exchangers and the refrigerant. Therefore, since it has been held that where the general conditions of the claim are disclosed in the prior art, discovering the optimum or workable ranges involves only routine skill in the art, “[w]here the general conditions of a claim are disclosed in the prior art, it is not inventive to discover the optimum or workable ranges by routine experimentation.” See In re Aller, 220 F.2d 454, 456, 105 USPQ 233, 235 (CCPA 1955). The discovery of an optimum value of a known result-effective variable, without producing any new or unexpected results, is within the ambit of a person of ordinary skill in the art. See In re Boesch, 205 USPQ 215 (CCPA 1980) (MPEP § 2144.05, II).
In regard to claim 21, Low teaches the system of claim 15, wherein the hybrid core-in-shell heat exchanger forms part of a liquid natural gas (LNG) production (col. 6, ln. 1-6; fig. 1).
In regard to claim 23, Low teaches the system of claim 15, wherein the first parameter of the first stream (20) and a second parameter of the second stream (31) each comprises a temperature or a pressure (see Table 1, streams 20 and 31).
Response to Arguments
Applicant’s arguments with respect to the amended claims have been considered but are moot in view of the new ground(s) of rejection.
Conclusion
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/W.M/Examiner, Art Unit 3763
/FRANTZ F JULES/Supervisory Patent Examiner, Art Unit 3763
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