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 .
DETAILED ACTION
Election/Restrictions
Applicant’s election without traverse of Group I in the reply filed on 7/9/2024 is acknowledged.
Claims 49, 51-54, 64, 90, 96, 100, 102, and 115 are withdrawn from further consideration pursuant to 37 CFR 1.142(b) as being drawn to a nonelected Group, there being no allowable generic or linking claim. Election was made without traverse in the reply filed on 7/9/2024.
Response to Arguments
Applicant's arguments filed 2/12/2026 have been fully considered but they are not persuasive.
Regarding the applicant’s argument that Karkow’s geometry does not meet the “adjacent” limitation, the examiner disagrees. Adjacent may mean simply close to or near, and Karkow shows the pilot burner near the flame holder. "Though understanding the claim language may be aided by explanations contained in the written description, it is important not to import into a claim limitations that are not part of the claim. For example, a particular embodiment appearing in the written description may not be read into a claim when the claim language is broader than the embodiment." Superguide Corp. v. DirecTV Enterprises, Inc., 358 F.3d 870, 875, 69 USPQ2d 1865, 1868 (Fed. Cir. 2004). See also Liebel-Flarsheim Co. v. Medrad Inc., 358 F.3d 898, 906, 69 USPQ2d 1801, 1807 (Fed. Cir. 2004).
In response to applicant's argument that Kahn does not sustain a momentum flame, the examiner disagrees. First, claim 8 recites “the pilot burner defines a plurality of fuel orifices having a sufficiently large collective area to collectively support a momentum pilot flame” (emphasis added). The applicant may be conflating “support” with “sustain.” Additionally, the applicant’s specification states “each distal pilot burner 1704 includes one or more manifolds that define a plurality of fuel orifices 1718 having a large collective area to collectively support a low momentum pilot flame (not shown)” emphasis added. The examiner believes the claim omits “low” in order to not unduly narrow the claim or to avoid terms of degree. This means that “momentum” simply means having a momentum which may be met by any pilot flame. Dividing the pilot flame between several orifices as in Kahn will produce a lower momentum flame.
Regarding the applicant’s argument that substituting Kahn’s structure would raise pilot jet momentum, localize the flame footprint, and materially alter heat-up dynamics, the examiner disagrees. The test for obviousness is not whether the features of a secondary reference may be bodily incorporated into the structure of the primary reference; nor is it that the claimed invention must be expressly suggested in any one or all of the references. Rather, the test is what the combined teachings of the references would have suggested to those of ordinary skill in the art. See In re Keller, 642 F.2d 413, 208 USPQ 871 (CCPA 1981). In this case, Kahn is relied upon to teach duplication of the fuel orifices of Karkow, not necessarily incorporate the exact structure of Kahn.
Claim Rejections - 35 USC § 102
The following is a quotation of the appropriate paragraphs of 35 U.S.C. 102 that form the basis for the rejections under this section made in this Office action:
A person shall be entitled to a patent unless –
(a)(1) the claimed invention was patented, described in a printed publication, or in public use, on sale, or otherwise available to the public before the effective filing date of the claimed invention.
Claims 1 and 27 are rejected under 35 U.S.C. 102(a)(1) as being anticipated by Karkow (US 20160290639 A1), hereinafter Karkow.
Regarding claim 1, Karkow discloses a burner system, comprising:
a pilot burner and a flame holder respectively disposed in a furnace at a distal position from one or more main fuel nozzles along a flow axis of a main fuel and combustion air, the pilot burner disposed upstream along the flow axis of and adjacent to the flame holder (“An igniter 106 is configured to selectably support an igniter flame 108 proximate to a path corresponding to the fuel stream 104 to cause the fuel stream 104 to support a combustion reaction 110a at the first flame location 112 corresponding to the igniter flame 108 during a first time interval. A distal flame holder 114 is configured to hold a combustion reaction 110b at a second flame location 116 defined by the distal flame holder 114” paragraph [0020]); and
the one or more main fuel nozzles disposed in the furnace at a proximal position along the flow axis and configured to output a main fuel (“a fuel nozzle 102 configured to output a fuel stream 104” paragraph [0020]);
wherein the flame holder, the pilot burner, and the one or more main fuel nozzles are separated along the flow axis by respective non-zero distances, wherein the flame holder is disposed more distal from the main fuel nozzles than the pilot burner along the flow axis (Figure 1A);
wherein the pilot burner is configured to support a pilot flame (“An igniter 106 is configured to selectably support an igniter flame 108” paragraph [0020]); and
wherein the pilot burner is disposed to cause the main fuel and combustion air to be ignited by the pilot flame (“igniter 106 is configured to selectably support an igniter flame 108 proximate to a path corresponding to the fuel stream 104 to cause the fuel stream 104 to support a combustion reaction 110a at the first flame location 112 corresponding to the igniter flame 108” paragraph [0020]).
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Regarding claim 27, Karkow discloses the burner system of claim 1, wherein the flame holder comprises a perforated flame holder (“a porous distal flame holder” paragraph [0052]).
Claim Rejections - 35 USC § 103
The following is a quotation of 35 U.S.C. 103 which forms the basis for all obviousness rejections set forth in this Office action:
A patent for a claimed invention may not be obtained, notwithstanding that the claimed invention is not identically disclosed as set forth in section 102, if the differences between the claimed invention and the prior art are such that the claimed invention as a whole would have been obvious before the effective filing date of the claimed invention to a person having ordinary skill in the art to which the claimed invention pertains. Patentability shall not be negated by the manner in which the invention was made.
The factual inquiries for establishing a background for determining obviousness under 35 U.S.C. 103 are summarized as follows:
1. Determining the scope and contents of the prior art.
2. Ascertaining the differences between the prior art and the claims at issue.
3. Resolving the level of ordinary skill in the pertinent art.
4. Considering objective evidence present in the application indicating obviousness or nonobviousness.
This application currently names joint inventors. In considering patentability of the claims the examiner presumes that the subject matter of the various claims was commonly owned as of the effective filing date of the claimed invention(s) absent any evidence to the contrary. Applicant is advised of the obligation under 37 CFR 1.56 to point out the inventor and effective filing dates of each claim that was not commonly owned as of the effective filing date of the later invention in order for the examiner to consider the applicability of 35 U.S.C. 102(b)(2)(C) for any potential 35 U.S.C. 102(a)(2) prior art against the later invention.
Claims 2-4, 20, and 188 are rejected under 35 U.S.C. 103 as being unpatentable over Karkow.
Regarding claims 2 and 4, Karkow discloses the burner system of claim 1, wherein the main flame comprises a flame having a heat output greater than the heat output of the pilot flame when the burner system is operating at a rated heat output (“A pilot flame is smaller” paragraph [0052]).
Karkow does not explicitly disclose wherein the main flame comprises a flame having a heat output of at least 10 or 20 times the heat output of the pilot flame. However, it has been held that “[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 MPEP §2144.05(II)(A) (quoting In re Aller, 220 F.2d 454, 456, 105 USPQ 233, 235 (CCPA 1955). Although, it has been further held that "[a] particular parameter must first be recognized as a result-effective variable, i.e. a variable which achieves a recognized result, before determination of the optimum or workable ranges of said variable might be characterized as routine experimentation. Refer to MPEP §2144.05(II)(B)(quoting In re Antonie, 559 F.2d 618, 195 USPQ 6 (CCPA 1977). In this case, Karkow discloses a pilot which is less power than the main flame, but does not specifically recite the main flame is 10 or 20 times the heat output of the pilot. Achieving wherein the main flame is 10 or 20 times the heat output of the pilot is a results-effective variable because it is desirable that the pilot be operated to consume as little fuel as possible while still supporting ignition. Accordingly, it would have been obvious to one of ordinary skill in the art at the time the invention was made to modify the main flame to be 10 or 20 times the heat output of the pilot, because the selection of relative heat output to achieve reduced fuel consumption without sacrificing main flame ignition constitutes the optimization of design parameters, which fails to distinguish the claim.
Regarding claim 3, Karkow discloses the burner system of claim 2, wherein operating at the rated heat output corresponds to operating in a steady state standard operating mode (“distal flame holder 114 is configured to hold a combustion reaction 110b at a second flame location 116 defined by the distal flame holder 114” paragraph [0020]).
Regarding claims 20 and 188, Karkow discloses the burner system of claim 1.
Karkow does not explicitly disclose wherein the pilot burner supports a diffusion flame at the distal location at least 100 main fuel nozzle diameters from the floor of the furnace, or wherein the distance between the main fuel nozzles and the pilot burner is at least 50 times a diameter of the main fuel nozzles. However, it has been held that “[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 MPEP §2144.05(II)(A) (quoting In re Aller, 220 F.2d 454, 456, 105 USPQ 233, 235 (CCPA 1955). Although, it has been further held that "[a] particular parameter must first be recognized as a result-effective variable, i.e. a variable which achieves a recognized result, before determination of the optimum or workable ranges of said variable might be characterized as routine experimentation. Refer to MPEP §2144.05(II)(B)(quoting In re Antonie, 559 F.2d 618, 195 USPQ 6 (CCPA 1977). In this case, Karkow discloses a main fuel nozzle which ostensibly have very small diameters, but does not specifically recite the claimed distances. Achieving the claimed distances is a results-effective variable because the distance between is a mixing distance. Accordingly, it would have been obvious to one of ordinary skill in the art at the time the invention was made to modify the distance, because the selection of distance to achieve appropriate mixing constitutes the optimization of design parameters, which fails to distinguish the claim.
Claims 5 and 48 are rejected under 35 U.S.C. 103 as being unpatentable over Karkow, in view of Kendrick (US 20170307212 A1), hereinafter Kendrick.
Regarding claim 5, Karkow discloses the burner system of claim 1, wherein the burner system has a NOx output of about twenty parts per million or less (“Combustion in a porous distal flame holder has been found by the inventors to output NOx below the 1 ppm detection limit of typical NO sensors” paragraph [0052]).
Karkow does not explicitly disclose a stack operatively coupled to the burner system, adjusted to 3% excess 02 at the stack.
However, Kendrick teaches a stack operatively coupled to the burner system, wherein the burner system has a NOx output of low double digit per million or less, adjusted to 3% excess 02 at the stack (“Experiments performed by the inventors have shown that perforated flame holders 102 described herein can support very clean combustion. Specifically, in experimental use of systems 100 ranging from pilot scale to full scale, output of oxides of nitrogen (NOx) was measured to range from low single digit parts per million (ppm) down to undetectable (less than 1 ppm) concentration of NOx at the stack. These remarkable results were measured at 3% (dry) oxygen (O.sub.2) concentration with undetectable carbon monoxide (CO) at stack temperatures typical of industrial furnace applications (1400-1600° F.). Moreover, these results did not require any extraordinary measures such as selective catalytic reduction (SCR), selective non-catalytic reduction (SNCR), water/steam injection, external flue gas recirculation (FGR), or other extremes that may be required for conventional burners to even approach such clean combustion” paragraph [0035]).
In view of Kendrick’s teachings, it would have been obvious to a person having ordinary skill in the art before the effective filing date of the invention to include a stack operatively coupled to the burner system, adjusted to 3% excess 02 at the stack as is taught in Kendrick, in the burner system disclosed by Karkow because maintaining low excess oxygen at the stack provides enough oxygen for complete combustion while operating at near stoichiometric conditions.
Regarding claim 48, Karkow discloses the burner system of claim 27.
Karkow does not disclose wherein the flame holder comprises wherein the perforated flame holder comprises perforations formed as passages between the reticulated fibers or in a reticulated ceramic foam.
However, Kendrick teaches wherein the flame holder wherein the perforated flame holder comprises perforations formed as passages between the reticulated fibers or in a reticulated ceramic foam (“the perforated flame holder body 208 can include fibers 339 including reticulated fibers. The fibers 339 can define branching perforations 210 that weave around and through the fibers 339. According to an embodiment, the perforations 210 are formed as passages through the reticulated fibers 339” paragraph [0071]).
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In view of Kendrick’s teachings, it would have been obvious to a person having ordinary skill in the art before the effective filing date of the invention to include wherein the flame holder wherein the perforated flame holder comprises perforations formed as passages between the reticulated fibers or in a reticulated ceramic foam as is taught in Kendrick, in the burner system disclosed by Karkow because Kendrick states “Experiments performed by the inventors have shown that perforated flame holders 102 described herein can support very clean combustion” (paragraph [0035]). Therefore, including the perforated flame holder of Kendrick will support very clean combustion in the burner system of Karkow.
Claims 8 and 12-14 are rejected under 35 U.S.C. 103 as being unpatentable over Karkow, in view of Kahn (US 1066622 A), hereinafter Kahn.
Regarding claims 8 and 12-14, Karkow discloses the burner system of claim 1.
Karkow does not disclose wherein the pilot burner defines a plurality of fuel orifices having a sufficiently large collective area to collectively support a momentum pilot flame, wherein the pilot burner comprises a fuel manifold having a plurality of segments joined together, each segment having a plurality of fuel orifices configured to pass fuel from inside the fuel manifold to a furnace combustion volume, wherein the plurality of segments are formed as respective tubes configured to freely pass the fuel delivered from a fuel pipe into the fuel manifold, wherein at least a portion of the tubes is arranged as spokes radiating from a center disposed substantially at a centerline along the axis
However, Kahn teaches wherein the pilot burner defines a plurality of fuel orifices having a sufficiently large collective area to collectively support a momentum pilot flame (13 and/or 15), wherein the pilot burner comprises a fuel manifold (8) having a plurality of segments joined together, each segment having a fuel orifices (15) configured to pass fuel from inside the fuel manifold to a combustion volume, wherein the plurality of segments are formed as respective tubes configured to freely pass the fuel delivered from a fuel pipe into the fuel manifold, wherein at least a portion of the tubes is arranged as spokes radiating from a center disposed substantially at a centerline along the axis (Figures 1 and 3).
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In view of Kahn’s teachings, it would have been obvious to a person having ordinary skill in the art before the effective filing date of the invention to include wherein the pilot burner defines a plurality of fuel orifices having a sufficiently large collective area to collectively support a momentum pilot flame, wherein the pilot burner comprises a fuel manifold having a plurality of segments joined together, each segment having a fuel orifices configured to pass fuel from inside the fuel manifold to a combustion volume, wherein the plurality of segments are formed as respective tubes configured to freely pass the fuel delivered from a fuel pipe into the fuel manifold, wherein at least a portion of the tubes is arranged as spokes radiating from a center disposed substantially at a centerline along the axis as is taught in Kahn, in the burner system disclosed by Karkow because Kahn states ”whereby gas may be simultaneously ignited in all of said burners” (page 1, line 13). Therefore, the configuration will improve the distribution of the pilot ignition. Additionally, the court has held that mere duplication of parts has no patentable significance unless a new and unexpected result is produced In re Harza, 274 F.2d 669, 124 USPQ 378 (CCPA 1960). In this case, each segment having a plurality of fuel orifices would divide the gas which is neither new nor unexpected. Therefore, including each segment having a plurality of fuel orifices has no patentable significance.
Claims 22, 28, 29, and 38 are rejected under 35 U.S.C. 103 as being unpatentable over Karkow, in view of Short (US 2476118 A), hereinafter Short.
Regarding claim 22, Karkow discloses the burner system of claim 1.
Karkow does not disclose wherein the pilot burner includes at least one tube disposed transverse to the fuel and combustion air flow axis.
However, Short teaches wherein the pilot burner includes at least one tube disposed transverse to the fuel and combustion air flow axis (“a small quantity of gas is supplied, through orifice 22, to one end of the pilot burner tube 23 provided with the usual air inlet opening 24. The pilot flame forms at one or a series of small openings 25 in the pilot burner tube” column 2, line 4).
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In view of Short’s teachings, it would have been obvious to a person having ordinary skill in the art before the effective filing date of the invention to include wherein the pilot burner includes at least one tube disposed transverse to the fuel and combustion air flow axis as is taught in Short, in the burner system disclosed by Karkow because the pilot of Short is more directly in the path of the main fuel path and will therefore provide more affirmative contact between the main fuel and pilot.
Regarding claim 28, 29, and 38, Karkow discloses the burner system of claim 1.
Karkow does not explicitly disclose wherein the pilot burner is a pre-mix burner configured to support the pilot flame using a pre-mixture of a pilot fuel and an oxidant;
a pilot pre-mix chamber;
a pilot fuel line fitting configured to output the pilot fuel into the pilot pre-mix chamber;
a pilot oxidant channel configured to output oxidant into the pilot pre-mix chamber; and
a pilot pre-mixture nozzle arranged to receive the pre-mixture of pilot fuel and oxidant from the pilot pre-mix chamber and output the pre-mixture of pilot fuel and oxidant into the furnace to support the pilot flame;
wherein the pilot pre-mix chamber, the pilot fuel line fitting, and the pilot oxidant channel are arranged to cause mixing of the pilot oxidant with the pilot fuel in the pilot pre-mix chamber to produce the pre-mixture of pilot fuel and oxidant;
a pilot igniter configured to ignite the pre-mixture of the pilot fuel and oxidant after the pre-mixture of the pilot fuel and oxidant is emitted from the pilot pre-mixture nozzle.
However, Short teaches wherein the pilot burner is a pre-mix burner configured to support the pilot flame using a pre-mixture of a pilot fuel and an oxidant (“a small quantity of gas is supplied, through orifice 22, to one end of the pilot burner tube 23 provided with the usual air inlet opening 24. The pilot flame forms at one or a series of small openings 25 in the pilot burner tube” column 2, line 4);
a pilot pre-mix chamber (at least a portion of 23 adjacent 24);
a pilot fuel line fitting configured to output the pilot fuel into the pilot pre-mix chamber (22);
a pilot oxidant channel configured to output oxidant into the pilot pre-mix chamber (24); and
a pilot pre-mixture nozzle arranged to receive the pre-mixture of pilot fuel and oxidant from the pilot pre-mix chamber and output the pre-mixture of pilot fuel and oxidant into the furnace to support the pilot flame (25);
wherein the pilot pre-mix chamber, the pilot fuel line fitting, and the pilot oxidant channel are arranged to cause mixing of the pilot oxidant with the pilot fuel in the pilot pre-mix chamber to produce the pre-mixture of pilot fuel and oxidant (The configuration of figure 1 mixes fuel and oxidant in tube 23);
a pilot igniter configured to ignite the pre-mixture of the pilot fuel and oxidant after the pre-mixture of the pilot fuel and oxidant is emitted from the pilot pre-mixture nozzle (“a series of small openings 25 in the pilot ]turner tube, adjacent to which Is an ignition coil 26” column 2, line 7).
Karkow discloses does not disclose the claimed combustible composition/the apparatus for introducing said composition. Short teaches the claimed combustible composition. The substitution of one known element (The combustible composition of Karkow) for another (The combustible composition of Short) would have been obvious to one having ordinary skill in the art at the time of the invention, since the substitution of the combustible composition taught in Short would have yielded predictable results, namely, a combustible pilot fuel for supporting combustion Agrizap, Inc. v. Woodstream Corp., 520 F.3d 1337, 86 USPQ2d 1110 (Fed. Cir. 2008).
Claim 23 is rejected under 35 U.S.C. 103 as being unpatentable over Karkow, in view of Short, and further in view of Mantz (US 2064436 A), hereinafter Mantz.
Regarding claim 23, Karkow, as modified by Short, discloses the burner system of claim 22.
Karkow, as modified by Short, does not disclose one or more sections of reticulated ceramic disposed superjacent to the at least one tube.
However, Mantz teaches one or more sections of reticulated ceramic disposed superjacent to the at least one tube (“pilot construction comprising a hollow ceramic tip of porous character, mounted directly upon a lighter tube carried by the gas supply manifold” page 1, line 6).
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In view of the teachings of Mantz, it would have been obvious to a person having ordinary skill in the art before the effective filing date of the invention to include one or more sections of reticulated ceramic disposed superjacent to the at least one tube as is taught in Mantz, in the burner system as presently modified because Mantz states “The present invention has for its primary, object the provision of a safety pilot which is incapable of becoming clogged by deposits of residues or gums from the gaseous fuel” (column 1, line 17) and ”The particular tip provided is capable of offering strong resistance to drafts, since the flame burns about the entire surface of the tip” (column 4, line 6). Therefore, including the reticulated ceramic taught by Mantz will prevent clogging of the pilot and improve resistance to drafts.
Claims 31, 34, and 37 are rejected under 35 U.S.C. 103 as being unpatentable over Karkow, in view of Short, and further in view of Karkow (US 20150330625 A1), hereinafter Karkow625.
Regarding claim 31, Karkow, as modified by Short, discloses the burner system according to claim 29.
Karkow, as modified by Short, does not disclose wherein the pilot burner further includes a flame arrestor disposed to cause the pre-mixture of pilot fuel and oxidant to flow through the flame arrestor as the pre-mixture of pilot fuel and oxidant flows from the pilot pre-mix chamber through the pilot pre-mixture nozzle.
However, Karkow625 teaches wherein the burner further includes a flame arrestor disposed to cause the pre-mixture of fuel and oxidant to flow through the flame arrestor as the pre-mixture of fuel and oxidant flows from the pre-mix chamber through the pre-mixture nozzle (“a flame arrestor can be disposed between the mixing chamber and the porous flame holder to prevent flashback” paragraph [0048]).
In view of the teachings of Karkow625, it would have been obvious to a person having ordinary skill in the art before the effective filing date of the invention to include a flame arrestor disposed to cause the pre-mixture of fuel and oxidant to flow through the flame arrestor as the pre-mixture of fuel and oxidant flows from the pre-mix chamber through the pre-mixture nozzle as is taught in Karkow625, in the burner system as presently modified because Karkow625 states that the arrestor prevents flashback. Therefore, including the arrestor will improve safety in the burner system as presently modified.
Regarding claims 34 and 37, Karkow, as modified by Short, discloses the burner system according to claim 29, wherein the pilot pre-mix chamber is disposed closer to the proximal position than to the distal position (The portion of 23 adjacent 24 is closer to the proximal end as taught by Short);
wherein the pilot pre-mix chamber comprises a pre-mixture pipe arranged to deliver the pre-mixture of the pilot fuel and oxidant from the pilot fuel line and pilot oxidant channel to a pilot burner distal assembly disposed adjacent to the distal position (As taught by Short);
wherein the pilot burner distal assembly includes the pilot pre-mixture nozzle (25 as taught by Short); and
wherein the pre-mixture pipe is configured to transmit the pilot fuel, the oxidant, and the pre-mixture thereof at a sufficiently high flow rate to cause a flow velocity to exceed a flame speed of the fuel and oxidant pre-mixture to prevent a flash-back of combustion into or through the pre-mixture pipe (The assembly of Short would not be designed to induce flashback).
Karkow, as modified by Short, does not disclose wherein the pilot burner distal assembly includes a flame arrestor arranged to pass the pre-mixture of the pilot fuel and oxidant from the pre-mixture pipe to the pilot pre-mixture nozzle and to prevent a flash-back of combustion from the pilot pre-mixture nozzle into the pilot pre-mixture pipe.
However, Karkow625 teaches wherein the burner assembly includes a flame arrestor arranged to pass the pre-mixture of the fuel and oxidant from the pre-mixture pipe to the pre-mixture nozzle and to prevent a flash-back of combustion from the pre-mixture nozzle into the pre-mixture pipe (“a flame arrestor can be disposed between the mixing chamber and the porous flame holder to prevent flashback” paragraph [0048]).
In view of the teachings of Karkow625, it would have been obvious to a person having ordinary skill in the art before the effective filing date of the invention to include wherein the burner assembly includes a flame arrestor arranged to pass the pre-mixture of the fuel and oxidant from the pre-mixture pipe to the pre-mixture nozzle and to prevent a flash-back of combustion from the pre-mixture nozzle into the pre-mixture pipe as is taught in Karkow625, in the burner system as presently modified because Karkow625 states that the arrestor prevents flashback. Therefore, including the arrestor will improve safety in the burner system as presently modified.
Claims 65 and 73 are rejected under 35 U.S.C. 103 as being unpatentable over Karkow, in view of Kendrick, and further in view of Fu (US 20180119954 A1), hereinafter Fu.
Regarding claims 65 and 73, Karkow discloses the burner system according to claim 1, further comprising:
the flame holder positioned in the furnace in a position to be preheated by the pilot flame during a preheating state and to hold a combustion reaction of the main fuel and combustion air adjacent to the flame holder during a standard operating state (“heat from the preheat flame is applied to the distal flame holder. At the end of a preheat period, during which the distal flame holder is heated to an operating temperature” paragraph [0050]);
a combustion sensor configured to sense a condition of the flame holder and to generate a sensor signal indicative of the condition of the flame holder (“a combustion system includes a sensor configured to detect the presence of a flame and to shut down the system if no flame is detected” paragraph [0054]);
one or more actuators configured to adjust a flow of the main fuel from the one or more main fuel nozzles, to adjust a flow of pilot fuel to the pilot burner (Valves are shown diagrammatically in figures 1A and 1B); and
a controller communicatively coupled to the actuators and the combustion sensor, the controller being configured to receive the sensor signal from the combustion sensor and to control the actuators to adjust the flow of the pilot fuel and the main fuel (“a combustion system includes a sensor configured to detect the presence of a flame and to shut down the system if no flame is detected” paragraph [0054]).
Karkow does not disclose:
a pilot flame sensor configured to sense a condition of the pilot flame and to output a sensor signal indicative of the condition of the pilot flame;
one or more actuators configured to adjust a flow of oxidant from an oxidant source;
the controller being configured to control the actuators to adjust the flow of the oxidant responsive to the sensor signal and in accordance with software instructions stored in a non-transitory computer readable medium coupled to the controller;
wherein the controller is configured to adjust a size of the pilot flame in response to the sensor signals from at least the combustion sensor by controlling one or more of the actuators to adjust the flow of the pilot fuel or the oxidant.
However, Kendrick teaches:
the flame holder positioned in the furnace in a position to be preheated by the pilot flame during a preheating state (“A burner system may include a device for preheating the perforated flame holder 102. For example, in some embodiments, as illustrated in FIG. 2A, the fuel nozzle assembly 104 may include an ignition and start-up flame source 120 such as a pilot or start-up nozzle 122 which may have a separate fuel feed (described in greater detail below with respect to, e.g., FIG. 5B). This pilot or start-up nozzle 122 may provide fuel for a pilot or start-up flame 206 to heat the perforated flame holder 102, as described in greater detail below” paragraph [0037]) and to hold a combustion reaction of the main fuel and combustion air adjacent to the flame holder during a standard operating state (“After the perforated flame holder is raised to the start-up temperature, the method proceeds to step 404, wherein fuel and oxidant are provided to the perforated flame holder and combustion is held by the perforated flame holder” paragraph [0089]);
a combustion sensor configured to sense a condition of the flame holder and to generate a sensor signal indicative of the condition of the flame holder (“The sensor 234 can include a heat sensor configured to detect infrared radiation or a temperature of the perforated flame holder 102 and convey data indicating a characteristic of the infrared radiation or temperature via a temperature indication output of the sensor 234” paragraph [0106]);
one or more actuators configured to adjust a flow of the main fuel from the one or more main fuel nozzles, to adjust a flow of pilot fuel to the pilot burner, and to adjust a flow of oxidant from an oxidant source (“the controller 230 may be configured to control at least one of fuel supply to the fuel nozzle 105, 218 and the ignition and start-up flame source 120. The controller 230 can be configured to control the fuel control valve 236 responsive to input from the combustion sensor 234. The controller 230 can be configured to control the fuel control valve 236 and/or oxidant blower or damper 238 to control a preheat flame type of heater 228 to heat the perforated flame holder 102 to an operating temperature. The controller 230 can similarly control the fuel control valve 236 and/or the oxidant blower or damper 238 to change the fuel and oxidant mixture 112 flow responsive to a heat demand change received as data via the data interface 232” paragraph [0109]); and
a controller communicatively coupled to the actuators and the combustion sensor, the controller being configured to receive the sensor signal from the combustion sensor and to control the actuators to adjust the flow of the pilot fuel, the main fuel, and the oxidant responsive to the sensor signal (230);
wherein the controller is configured to adjust a size of the pilot flame in response to the sensor signals from at least the combustion sensor by controlling one or more of the actuators to adjust the flow of the pilot fuel or the oxidant (“the controller 230 can be configured to control a start-up flame holder actuator configured to cause the start-up flame holder (such as the proximal flame holder described above) to hold the start-up flame 206 when the perforated flame holder 102 needs to be preheated and to not hold the start-up flame when the perforated flame holder 102 is at an operating temperature” paragraph [0100]).
In view of Kendrick’s teachings, it would have been obvious to a person having ordinary skill in the art before the effective filing date of the invention to include these features as is taught in Kendrick, in the burner system disclosed by Karkow because Kendrick states “Experiments performed by the inventors have shown that perforated flame holders 102 described herein can support very clean combustion” (paragraph [0035]). Therefore, including the perforated flame holder of Kendrick will support very clean combustion in the burner system of Karkow.
Karkow, as modified by Kendrick, does not disclose:
a pilot flame sensor configured to sense a condition of the pilot flame and to output a sensor signal indicative of the condition of the pilot flame;
controlling in accordance with software instructions stored in a non-transitory computer readable medium coupled to the controller.
However, Fu teaches:
a pilot flame sensor configured to sense a condition of the pilot flame and to output a sensor signal indicative of the condition of the pilot flame (“after a successful ignition when using the first fuel (e.g., natural gas), a flame will be generated by (or on) the first burner 12 of the first pilot burner 11, and the first thermocouple 14 will in turn be sufficiently heated (e.g., due to its proximity and/or sensitivity to the first burner 12) to generate thermoelectric potential (and/or Fe-ion when using a Fe-ion sensor)” paragraph [0050]);
controlling in accordance with software instructions stored in a non-transitory computer readable medium coupled to the controller (“Each computing device 1510 additionally can have memory 1512, one or more input controllers 1516, one or more output controllers 1515, and/or one or more communication connections 1540. The memory 1512 can be volatile memory (e.g., registers, cache, RAM, etc.), non-volatile memory (e.g., ROM, EEPROM, flash memory, etc.), or some combination thereof. In at least one embodiment, the memory 1512 can store software implementing described techniques” paragraph [0059]).
In view of Fu’s teachings, it would have been obvious to a person having ordinary skill in the art before the effective filing date of the invention to include a pilot flame sensor configured to sense a condition of the pilot flame and to output a sensor signal indicative of the condition of the pilot flame as is taught in Fu, in the burner system disclosed by Karkow because Fu states “the system uses one or more thermocouples and a printed circuit board to identify fuel type. In an embodiment with two sets of thermocouples, both can be energized by ignition, but each can have a different reaction to ignition. The difference can be detected (e.g., digitally) by the printed circuit board to determine which type or kind of fuel (e.g., gas) is being supplied and to control valves of the system accordingly” (paragraph [0008]). Therefore, including the pilot sensor will enable use of different fuels.
Additionally, the substitution of one known element (the controller of Kendrick) for another (the controller of Fu) would have been obvious to one having ordinary skill in the art at the time of the invention, since the substitution of the controller taught in Fu would have yielded predictable results, namely, means of controlling the burner system Agrizap, Inc. v. Woodstream Corp., 520 F.3d 1337, 86 USPQ2d 1110 (Fed. Cir. 2008).
Claim 68 is rejected under 35 U.S.C. 103 as being unpatentable over Karkow, in view of Kendrick, in view of Fu, and further in view of Liu (NPL, Study of flame characteristics using electric capacitance tomography), hereinafter Liu.
Regarding claim 68, Karkow, as modified by Kendrick and Fu, discloses the burner system according to claim 65.
Karkow, as modified by Kendrick and Fu, does not disclose wherein the pilot flame sensor includes at least one of an electrocapacitive sensor, an electro resistive sensor, and a tomographic sensor.
However, Liu teaches wherein the flame sensor includes at least one of an electrocapacitive sensor, an electro resistive sensor, and a tomographic sensor (“Electrical capacitance tomography (ECT) is a type of process tomography (PT) based on capacitance sensing. It features are fast response, low cost, easy implementation, non-intrusiveness, non-radiation and has the capability of acquiring 2D or 3D process parameter information. As a promising technique, ECT is widely applied in many aspects and is becoming one of the key topics in PT research [1-3]. Researchers pursuing visual measurements have obtained the in-cylinder distribution information, such as position, size and pulsation, of a premixed flame and free space using an ECT sensor [4-7]” introduction).
In view of Liu’s teachings, it would have been obvious to a person having ordinary skill in the art before the effective filing date of the invention to include wherein the flame sensor includes at least one of an electrocapacitive sensor, an electro resistive sensor, and a tomographic sensor as is taught in Liu, in the burner system as presently modified because Liu states that ECT is a fast response, low cost, easy implementation. Therefore, including ECT will improve responsiveness and simplify implementation of the sensor.
Claims 189 and 190 are rejected under 35 U.S.C. 103 as being unpatentable over Karkow, in view of Wallace (US 2971577 A), hereinafter Wallace.
Regarding claims 189 and 190, Karkow discloses the burner system of Claim 1.
Karkow does not disclose a mixing tube disposed between the one or more main fuel nozzles and the flame holder, wherein the mixing tube comprises a proximal end, disposed proximate to the one or more main fuel nozzles, and a distal end, disposed proximate to the flame holder.
However, Wallace teaches a mixing tube disposed between the one or more main fuel nozzles and the flame holder, wherein the mixing tube comprises a proximal end, disposed proximate to the one or more main fuel nozzles (“a portion of the combustion air (the primary air) is caused to enter the inlet ends 22 of the mixing tubes M where it mixes with gas from the gas jets or nozzles 20” column 3, line 29), and a distal end, disposed proximate to the flame holder (“Disposed in the outlet ends 24 of the mixing tubes M are flame holder units 32” column 3, line 16).
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In view of Wallace’s teachings, it would have been obvious to a person having ordinary skill in the art before the effective filing date of the invention to include a mixing tube as is taught in Wallace, in the burner system disclosed by Karkow because mixing tubes improve mixing of fuel and air which improves combustion.
Claim 194 is rejected under 35 U.S.C. 103 as being unpatentable over Karkow, in view of Colket (US 5318436 A), hereinafter Colket.
Regarding claim 194, Karkow discloses the burner system of Claim 1.
Karkow does not disclose wherein the pilot burner continues to support the pilot flame while the flame holder holds at least a portion of a combustion reaction of the main fuel and combustion air.
However, Colket teaches wherein the pilot burner continues to support the pilot flame while the flame holder holds at least a portion of a combustion reaction of the main fuel and combustion air (“The burner 2 includes a mixing chamber 6, in which a fuel and air mix before burning, a flame holder 8 that stabilizes a main flame, and a pilot 10, which also stabilizes the main flame” column 3, line 46).
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In view of Colket’s teachings, it would have been obvious to a person having ordinary skill in the art before the effective filing date of the invention to include wherein the pilot burner continues to support the pilot flame while the flame holder holds at least a portion of a combustion reaction of the main fuel and combustion air as is taught in Colket, in the burner system disclosed by Karkow because Colket states “Flame stability can be improved by supplementing the main flame with a pilot flame to ensure that the main flame remains lit, even at very lean conditions” (column 1, line 60). Therefore, continuing support of the pilot flame will improve main flame stability.
Allowable Subject Matter
Claims 77, 78, 82, 84, 85, and 191-193, are objected to as being dependent upon a rejected base claim, but would be allowable if rewritten in independent form including all of the limitations of the base claim and any intervening claims.
Regarding Claim 77, Karkow as modified by Kendrick, Fu, and Liu represents the closest prior art of record. However, Karkow as modified, does not disclose that the electrocapacitive sensor includes a first set of electrodes positioned laterally around the distal flame holder and configured to sense a parameter in a vicinity of the distal flame holder, as recited in claim 77. Furthermore, there is no other prior art of record that reads on this limitation, or can be reasonably combined with Karkow as modified by Kendrick, Fu, and Liu, without unreasonable hindsight reconstruction of the claimed invention. Therefore, this limitation in dependent claim 77, in combination with the limitations of claims 1, 65, and 68, contains allowable subject matter.
Claim 78 contains allowable subject matter by virtue of its dependency from claim 77.
Regarding Claim 82, Karkow as modified by Kendrick, Fu, and Liu represents the closest prior art of record. However, Karkow as modified, does not disclose that the plurality of electrodes include one or more pairs of electrodes each separated from each other by the distal flame holder, as recited in claim 82. Furthermore, there is no other prior art of record that reads on this limitation, or can be reasonably combined with Karkow as modified by Kendrick, Fu, and Liu, without unreasonable hindsight reconstruction of the claimed invention. Therefore, this limitation in dependent claim 77, in combination with the limitations of claims 1, 65, and 68, contains allowable subject matter.
Claim 84 and 85 contain allowable subject matter by virtue of its dependency from claim 82.
Regarding Claim 191, Karkow, as modified by Wallace, represents the closest prior art of record. However, Karkow as modified does not disclose wherein the pilot burner is disposed between the distal flame holder and the distal end of the mixing tube, as recited in claim 191. No art was found such that further modification of Karkow and Wallace would have rendered the claim obvious. Therefore, these limitations, when combined with every other limitation of the base and intermediate claims, distinguishes the claim from the prior art.
Claims 192 and 193 contain allowable subject matter by virtue of its dependency from claim 82.
Conclusion
The prior art made of record and not relied upon is considered pertinent to applicant's disclosure:
Haedike (US 2263170 A)
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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.
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/LOGAN P JONES/Examiner, Art Unit 3762 /MICHAEL G HOANG/Supervisory Patent Examiner, Art Unit 3762
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