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 7 and 14 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 7 and 14 recite “high H2 fuel”. The term or phrase “high H2 fuel” is a relative term which renders the claim indefinite. The term “high H2 fuel” is not defined by the claim, the specification does not provide a standard for ascertaining the requisite degree, and one of ordinary skill in the art would not be reasonably apprised of the scope of the invention. It is unclear what volume percentage (or other relative measure) defines “high H2 fuel”.
Claim Rejections - 35 USC § 102
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 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, 3-6 and 8 are rejected under 35 U.S.C. 102(a)(1) as being anticipated by EP 3009741 A1 (hereinafter “BÖHMER”).
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Regarding Claims 1, 3-6 and 8, BÖHMER discloses a heater, comprising: a radiant section (14); a burner (22) located on a lower portion of the radiant section, the burner configured to receive a primary fuel stream (26) and a primary combustion air stream (52) through the burner to support a primary combustion reaction local to the burner (see primary flame 58); and a remote air pipe (38, 46) disposed on an upper portion of the radiant section (16) distal from the burner (22) and spaced from an envelope of the primary combustion reaction (see again primary flame 58), the remote air pipe configured to inject a remote combustion air stream into the radiant section to support a secondary combustion reaction (see 48; see also para. [0002]: “Air staging (also known as overfire air) is a well-known design feature for NOx control in boilers and furnaces, e.g. power plant boilers, industrial boilers for generating steam and/or hot water. Air staging involves a separation of combustion air into a primary air flow and a secondary air flow. The primary air - the majority of the total amount of combustion air - is mixed with the respective fuel in a burner, where combustion occurs at a relative low temperature producing a flue gas that is rich in fuel and deficient regarding oxygen, and moderate amounts of NOx are formed. The secondary air - the remaining combustion air - is introduced into the flue gas downstream of the burner(s) in a secondary combustion zone. There complete combustion and burnout are achieved again at a relatively low temperature minimizing the production of NOx.”; see also para. [0007]: “During operation a primary combustion zone and a secondary combustion zone can be distinguished in the combustion chamber. In the primary combustion zone fuel is combusted with the bulk of the total combustion air, typically 60-90%, while the secondary combustion air (the remaining volume 10-40% of the total combustion air) is fed to the secondary combustion zone, downstream the primary combustion zone.”); wherein the primary combustion air stream includes a majority of the total air introduced to the radiant section by the combination of the primary combustion air stream and the remote combustion air stream (see para. [0006]: “Primary combustion air, typically 60 - 90 vol.% of the total amount of combustion air, is also fed to the burner via a primary air supply, suitably a wind-box.”; see also para. [0007]: “During operation a primary combustion zone and a secondary combustion zone can be distinguished in the combustion chamber. In the primary combustion zone fuel is combusted with the bulk of the total combustion air, typically 60-90%, while the secondary combustion air (the remaining volume 10-40% of the total combustion air) is fed to the secondary combustion zone, downstream the primary combustion zone.”); wherein the primary fuel stream (26) is all of the fuel introduced to the radiant section (16); wherein the remote air pipe (38, 46) is configured to only inject the remote combustion air stream into the radiant section (16); wherein the primary combustion reaction is sub-stoichiometric combustion that minimizes NOx formation and the secondary combustion reaction is lean combustion that further lowers NOx emissions concentration (see 48; see also para. [0002]: “Air staging (also known as overfire air) is a well-known design feature for NOx control in boilers and furnaces, e.g. power plant boilers, industrial boilers for generating steam and/or hot water. Air staging involves a separation of combustion air into a primary air flow and a secondary air flow. The primary air - the majority of the total amount of combustion air - is mixed with the respective fuel in a burner, where combustion occurs at a relative low temperature producing a flue gas that is rich in fuel and deficient regarding oxygen, and moderate amounts of NOx are formed. The secondary air - the remaining combustion air - is introduced into the flue gas downstream of the burner(s) in a secondary combustion zone. There complete combustion and burnout are achieved again at a relatively low temperature minimizing the production of NOx.”; see also para. [0007]: “During operation a primary combustion zone and a secondary combustion zone can be distinguished in the combustion chamber. In the primary combustion zone fuel is combusted with the bulk of the total combustion air, typically 60-90%, while the secondary combustion air (the remaining volume 10-40% of the total combustion air) is fed to the secondary combustion zone, downstream the primary combustion zone.”); wherein the remote air pipe (38) extends vertically upward or vertically downward through the upper portion of the radiant section (16) to provide preheating of the remote combustion air stream via heat duty from the radiant section (16).
Claim Rejections - 35 USC § 103
In the event the determination of the status of the application as subject to AIA 35 U.S.C. 102 and 103 (or as subject to pre-AIA 35 U.S.C. 102 and 103) is incorrect, any correction of the statutory basis (i.e., changing from AIA to pre-AIA ) for the rejection will not be considered a new ground of rejection if the prior art relied upon, and the rationale supporting the rejection, would be the same under either status.
The following is a quotation of 35 U.S.C. 103 which forms the basis for all obviousness rejections set forth in this Office action:
A patent for a claimed invention may not be obtained, notwithstanding that the claimed invention is not identically disclosed as set forth in section 102, if the differences between the claimed invention and the prior art are such that the claimed invention as a whole would have been obvious before the effective filing date of the claimed invention to a person having ordinary skill in the art to which the claimed invention pertains. Patentability shall not be negated by the manner in which the invention was made.
The factual inquiries for establishing a background for determining obviousness under 35 U.S.C. 103 are summarized as follows:
1. Determining the scope and contents of the prior art.
2. Ascertaining the differences between the prior art and the claims at issue.
3. Resolving the level of ordinary skill in the pertinent art.
4. Considering objective evidence present in the application indicating obviousness or nonobviousness.
This application currently names joint inventors. In considering patentability of the claims the examiner presumes that the subject matter of the various claims was commonly owned as of the effective filing date of the claimed invention(s) absent any evidence to the contrary. Applicant is advised of the obligation under 37 CFR 1.56 to point out the inventor and effective filing dates of each claim that was not commonly owned as of the effective filing date of the later invention in order for the examiner to consider the applicability of 35 U.S.C. 102(b)(2)(C) for any potential 35 U.S.C. 102(a)(2) prior art against the later invention.
Claims 2, 11-13, 16 and 20 are rejected under 35 U.S.C. 103 as being unpatentable over BÖHMER.
Regarding Claim 2, BÖHMER does not explicitly disclose wherein the remote air pipe is spaced from the burner by a distance of at least two meters.
Nonetheless, it would have been obvious to one having ordinary skill in the art at the time the invention was made to modify BÖHMER wherein the remote air pipe is spaced from the burner by a distance of at least two meters, since it has been held that discovering an optimum value of a result effective variable involves only routine skill in the art. See MPEP 2144.05(II). In the present case, BÖHMER discloses, at para. [0008]: “In this embodiment the secondary air supply is a manifold system comprising at least an inlet duct for secondary air in fluid communication with a distribution channel. The distribution channel is provided with a plurality of injection nozzles for delivering the secondary air to the flue gas. E.g. the injection nozzles are spaced apart, such as at predetermined intervals. The injection nozzles can be grouped together forming subgroups of closely set nozzles, while the distance between subgroups might vary. The size of the nozzle openings might vary as well. The injection nozzles are preferably designed, including number, position, dimensions and direction, such that an intimate mixing with the flue gas occurs in the secondary combustion zone. The peripheral distribution channel such as an annular passageway, e.g. made from metal, refractory materials and/or concrete, extends in a direction perpendicular to the main flow of gas, and as it projects away from the enclosure wall to the centre, it forms a flow restriction for the flue gas flow. This restriction contributes to internal recirculation of flue gas, if any depending on the type of burner and design of boiler or furnace, which is beneficial in suppressing NOx generation This restriction also acts as a venturi thereby enhancing the draw of flue gas to the outlet and promoting the thorough mixing of the secondary air with the flue gas, thereby on its turn improving complete combustion and burnout.” (Emphasis mine). The results effective variable in this case comprises positioning said remote air pipe spaced from the burner by a distance such that an intimate mixing with the flue gas occurs in the secondary combustion zone. In addition, the position of the secondary air outlets from said remote air pipe forms a flow restriction for the flue gas flow. This restriction contributes to internal recirculation of flue gas, if any depending on the type of burner and design of boiler or furnace, which is beneficial in suppressing NOx generation This restriction also acts as a venturi thereby enhancing the draw of flue gas to the outlet and promoting the thorough mixing of the secondary air with the flue gas, thereby on its turn improving complete combustion and burnout.
Regarding Claims 11-13, 16 and 20, BÖHMER discloses all of the claim limitations as is evident from the discussion of Claims 1-6 and 8 above. The limitations of independent Claim 11 are a combination of the limitations of Claims 2 and 6 (including the limitations of the parent claim, independent Claim 1). The limitations of Claims 12-13, 16 and 20 either mirror the limitations of Claims 1-6 and 8 or are the same limitation(s) stated alternatively.
Claims 7 and 9 are rejected under 35 U.S.C. 103 as being unpatentable over BÖHMER in view of US 20080286706 A1 (hereinafter “PONZI”).
Regarding Claim 7, BÖHMER does not disclose wherein the primary fuel stream is high H2 fuel.
PONZI teaches a heater wherein the primary fuel stream is high H2 fuel (see para. [0044]: “As used herein, "conventional fuel" refers to mixtures comprising methane, hydrogen, and higher hydrocarbons that exist as vapors as they enter the furnace. Non-limiting examples of conventional fuels include refinery or petrochemical fuel gases, natural gas, or hydrogen. As used herein, "synthesis gas" is defined as a mixture comprising carbon monoxide and hydrogen. Non-limiting examples of synthesis gas fuels include the products of the gasification or partial oxidation of petroleum coke, vacuum residues, coal, or crude oils. All ratios and percentage values used herein are based on mass unless specifically indicated otherwise.”).
It would have been obvious to one having ordinary skill in the art before the effective filing date of the invention to modify BÖHMER wherein the primary fuel stream is high H2 fuel as taught and/or suggested by PONZI, since both references teach a fuel-fired heater, it would have been obvious to one skilled in the art to substitute one fuel for the other to achieve the predictable result of generating a flame.
Regarding Claim 9, BÖHMER discloses wherein the burner (22) is a hearth burner.
BÖHMER does not disclose the heater further comprising: a wall burner located at the upper portion of the radiant section and configured to burn any remaining hydrocarbons from the primary fuel stream following the primary combustion reaction and the secondary combustion reaction in a tertiary combustion reaction local to the wall burner.
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PONZI teaches a heater wherein the burner (46) is a hearth burner, the heater further comprising: a wall burner (56) located at the upper portion of the radiant section (see 34, 36) and configured to burn any remaining hydrocarbons from the primary fuel stream following the primary combustion reaction (generated by burner 46) and the secondary combustion reaction (generated by one or more of the lowest wall burners 56) in a tertiary combustion reaction local to the wall burner (generated by one or more of the highest wall burners 56).
It would have been obvious to one having ordinary skill in the art before the effective filing date of the invention to modify BÖHMER by further comprising: a wall burner located at the upper portion of the radiant section and configured to burn any remaining hydrocarbons from the primary fuel stream following the primary combustion reaction and the secondary combustion reaction in a tertiary combustion reaction local to the wall burner as taught and/or suggested by PONZI, since PONZI states at para. [0056]: “The excess air from the hearth burner flame mixes with the fuel rich effluent from the wall burner and combusts at higher elevation in the firebox as compared to conventional furnace operating conditions. This reduces hearth burner-wall burner interaction, preventing the vertical flame of the hearth burner from detaching from the wall and forming hot spots. It is also responsible for reducing NOx.” And, states at para. [0058]: “The combination of more excess air in the hearth burners and sub-stoichiometric air in the wall burners thus also reduces NOx and provides a smoother heat release profile across the vertical length of the firebox, and promotes more uniform coil metal temperatures and better use of coil metallurgy. In sum, operating a pyrolysis furnace according to the disclosed firing pattern improves coil utilization by effecting greater uniformity in the tube metal temperature and flux profile over the coil throughout the elevation of the firebox as evidenced by the data provided below.”
Claim 17 is rejected under 35 U.S.C. 103 as being unpatentable over BÖHMER in view of US 6085674 A (hereinafter “ASHWORTH”).
Regarding Claim 17, BÖHMER does not disclose wherein the burner is a first burner, the heater further comprising: a second burner located on the side wall of the radiant section proximate the remote air pipe.
ASHWORTH teaches a heater wherein the burner is a first burner (10), the heater further comprising: a second burner (also 10) located on the side wall of the radiant section proximate the remote air pipe (see 32).
It would have been obvious to one having ordinary skill in the art before the effective filing date of the invention to modify BÖHMER wherein the burner is a first burner, the heater further comprising: a second burner located on the side wall of the radiant section proximate the remote air pipe as taught and/or suggested by ASHWORTH, since ASHWORTH’s Abstract states that such an arrangement results in “a method and apparatus for reducing NOx emissions from the combustion of carbonaceous fuels using three stages of oxidation. In the first stage, a partial oxidation combustor is used to partially combust the fuel in the presence of heated combustion air. The fuel gas produced in the partial oxidation process is passed to a second stage partial oxidation combustor while molten slag is removed and disposed of. A second preheated combustion air is introduced into the second stage combustor to produce a reducing flue gas. A third combustion air is mixed with the flue gas in a third stage combustor to substantially complete the combustion process… The stochiometric ratios at each stage of combustion are controlled to minimize overall NOx emissions to acceptable levels.”
Claim 18 is rejected under 35 U.S.C. 103 as being unpatentable over BÖHMER in view of ASHWORTH as applied to Claim 17 above, and further in view of US 20090136880 A1 (hereinafter “HENDERSHOT”).
Regarding Claim 18, BÖHMER in view of ASHWORTH does not disclose wherein the second burner is a single row of wall burners configured to support a tertiary combustion reaction to burn any remaining hydrocarbon in the primary fuel stream following the primary combustion reaction and the secondary combustion reaction.
HENDERSHOT teaches a heater wherein the second burner (20) is a single row of wall burners configured to support a tertiary combustion reaction (see the uppermost row of burners 20) to burn any remaining hydrocarbon in the primary fuel stream following the primary combustion reaction (see hearth/floor burners 10) and the secondary combustion reaction (see low rows of burners 20 below the uppermost row of burners 20).
It would have been obvious to one having ordinary skill in the art before the effective filing date of the invention to modify BÖHMER in view of ASHWORTH wherein the second burner is a single row of wall burners configured to support a tertiary combustion reaction to burn any remaining hydrocarbon in the primary fuel stream following the primary combustion reaction and the secondary combustion reaction as taught and/or suggested by HENDERSHOT, since it has been 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). See also DUPLICATION OF PARTS: MPEP 2144.04 (VI-B). In the present case, the desired heat out of said second burner is simply divided into a number of wall burners rather than a singular wall burner.
Claims 14 and 15 are rejected under 35 U.S.C. 103 as being unpatentable over BÖHMER in view of EP 0543155 A1 (hereinafter “HAUMANN”).
Regarding Claim 14, BÖHMER does not explicitly disclose wherein the primary combustion air stream is preheated, or the primary fuel stream is high H2 fuel, or both.
HAUMANN teaches a heater wherein the primary combustion air stream (26) is preheated.
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It would have been obvious to one having ordinary skill in the art before the effective filing date of the invention to modify BÖHMER wherein the primary combustion air stream is preheated as taught and/or suggested by HAUMANN, since combustion air preheating is known to enhance the suppression of NOx formation, see the provide English translation of HAUMANN which states: “The proposed solution is a double air staging method. The substoichiometric operation of a boiler can reduce nitrogenous fuel compounds. Reaction kinetic studies show a pronounced optimum for the air ratio. The reduction mechanism increases with increasing air preheating. The optimum shifts to richer operating conditions. If fuel and air are premixed, a combustion process can be realized at the optimum point. The main advantage of the invention is that, as a result of these findings, the air is preheated above the previous level before a very rich, but homogeneous mixture of fuel and primary air is generated in burners, the mixture then being partially burned in a pre-combustion chamber becomes. The time spent in this pre-combustion chamber is selected so that the breakdown of nitrogen compounds (TFN = total fixed nitrogen) is well advanced.”
Regarding Claim 15, BÖHMER does not disclose wherein the remote air pipe extends through the side wall of the radiant section without a substantial change in direction.
HAUMANN teaches a heater wherein the remote air pipe (see 28) extends through the side wall of the radiant section (22) without a substantial change in direction (see Fig. 1).
It would have been obvious to one having ordinary skill in the art before the effective filing date of the invention to modify BÖHMER wherein the remote air pipe extends through the side wall of the radiant section without a substantial change in direction as taught and/or suggested by HAUMANN, since such a modification would provided the tubing/pipework/ducting required for said remote air pipe substantially external to said radiant section thereby providing easier access to said tubing/pipework/ducting for purposes such as inspection, maintenance, repair or replacement.
Allowable Subject Matter
Claims 10 and 19 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.
Conclusion
The prior art made of record and not relied upon is considered pertinent to applicant's disclosure because the references are either in the same field of endeavor or are reasonably pertinent to the particular problem with which the applicant was concerned. Please see form PTO-892 (Notice of References Cited) attached to, or included with, this Office Action.
Any inquiry concerning this communication or earlier communications from the examiner should be directed to JORGE A PEREIRO whose telephone number is (571)270-3932 and whose fax number is (571) 270-4932. The examiner can normally be reached on M-F 9:00 - 5:00 EST.
If attempts to reach the examiner by telephone are unsuccessful, the examiner’s supervisor, Helena Kosanovic can be reached at (571) 272-9059. The fax phone number for the organization where this application or proceeding is assigned is 571-273-8300.
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/JORGE A PEREIRO/ Primary Examiner, Art Unit 3799
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