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 .
Response to Arguments
Applicant's arguments filed 12/04/2025 have been fully considered but they are not persuasive. The applicant argues, on pp. 9-10 of the response, that Bocci does not disclose an auxiliary oxidant because the atomizing fluid issued through outer duct 12 is not explicitly disclosed as participating in the combustion reaction. The examiner respectfully disagrees. Bocci explicitly discloses that the atomizing fluid can be air, column 2 lines 12-13, since the atomizing fluid must be injected in intimate contact with the fuel (in order to atomize it) a person having ordinary skill in the art at the time of the filing date of the invention would recognize that the atomizing air would participate in the reaction despite Bocci not explicitly disclosing it. For this reason, the rejections are maintained.
Applicant’s arguments, see pp. 11, filed 12/04/2025, with respect to the 35 U.S.C 112(b) rejections of claims 7 and 9 have been fully considered and are persuasive. The 35 U.S.C 112(b) rejections of claims 7 and 9 have been withdrawn.
The applicant’s amendments of claims 6-7, 10-17, 19-20, and 25-26 overcome the 35 U.S.C 112(b) rejections presented in the Non-Final rejection dated 10/21/2025.
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.
Claim(s) 1 and 4-5 is/are rejected under 35 U.S.C. 102(a)(1) as being anticipated by Bocci et. al (US 4,451,230).
With respect to claim 1 Bocci discloses a burner (1), comprising a central main fuel lance [reference character 13] for supply of a liquid fuel having a main fuel outlet [reference character 14] at its downstream end, a main oxidant conduit [reference character 2] for supply of a main oxidant, having a main oxidant outlet [see annotated Fig. below] at its downstream end, a pilot fuel conduit [reference character 1] for supply of a gaseous pilot fuel1, having a pilot fuel outlet [see annotated Fig. below] at its downstream end, and an auxiliary oxidant conduit [reference character 12] for supply of an auxiliary oxidant, having an auxiliary oxidant outlet at its downstream end, wherein at least in the downstream portion (5) of the burner (1), in which main fuel outlet (14), main oxidant outlet (44), pilot fuel outlet (24) and auxiliary oxidant outlet (34) are present, the pilot fuel conduit (20), the auxiliary oxidant conduit (30) and the main oxidant conduit (40) are arranged concentrically around the central main fuel lance (10) so that central main fuel lance (10) is surrounded by the pilot fuel conduit (20), the auxiliary oxidant conduit (30) and the main oxidant conduit (40), wherein at least in said downstream portion (5) of the burner (1) the central main fuel lance (10), the pilot fuel conduit (20) and the auxiliary oxidant conduit (30) are surrounded by the main oxidant conduit (40) [see Fig. 1].
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With respect to claim 4 Bocci discloses that the main oxidant conduit (40) in said downstream section of the burner (1) comprises a swirler section [reference character 15] upstream of the main oxidant outlet.
With respect to claim 5 Bocci discloses that the outlet plane (25) of the pilot fuel outlet (24) is recessed in upstream direction from outlet plane (15) of the main fuel outlet (14) by a distance L1 [see annotated Fig. above].
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.
Claim(s) 1-3, 9, 15, 18, and 25-26 is/are rejected under 35 U.S.C. 103 as being unpatentable over Ihlenfield (US 3,163,203) in view of Bunn (US 4,610,625).
With respect to claim 1 Ihlenfield discloses a burner comprising a central main fuel lance [reference character 25] for supply of a liquid fuel having a main fuel outlet [reference character 30] at its downstream end, a main oxidant conduit [reference character 18] for supply of a main oxidant, having a main oxidant outlet [see annotated Fig. below] at its downstream end, and an auxiliary oxidant conduit [reference character 22] for supply of an auxiliary oxidant, having an auxiliary oxidant outlet [at reference character 31] at its downstream end, wherein at least in the downstream portion of the burner, in which main fuel outlet, main oxidant outlet, and auxiliary oxidant outlet are present, the auxiliary oxidant conduit and the main oxidant conduit are arranged concentrically around the central main fuel lance so that central main fuel lance is surrounded by the auxiliary oxidant conduit and the main oxidant conduit, wherein at least in said downstream portion of the burner the central main fuel lance [see Fig. 1].
Ihlenfield does not disclose a pilot fuel conduit for supply of a gaseous pilot fuel, having a pilot fuel outlet at the downstream end of the burner pilot fuel outlet such that the main fuel lance is surrounded by the pilot fuel conduit, the auxiliary oxidant conduit, and the main oxidant conduit, wherein at least in said downstream portion of the burner the central main fuel lance, the pilot fuel conduit and the auxiliary oxidant conduit are surrounded by the main oxidant conduit.
Bunn discloses a burner having a pilot fuel conduit [reference character 30] surrounding a central structure [reference character 34] which is concentrically arranged within a main oxidant conduit [reference character 26].
It would have been obvious to one of ordinary skill in the art at the time of the filing date of the invention to modify the structure taught by Ihlenfield by providing a pilot fuel and air conduit surrounding the central fuel lance, as taught by Bunn, where the central structure of Bunn [reference character 34] is analogous to the fuel lance, in order to provide a pilot flame immediately adjacent to the central fuel lance.
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With respect to claim 2 the combination of Ihlenfield and Bunn disclose a secondary fuel conduit [reference character 16] for supply of a secondary fuel, having a secondary fuel outlet [reference character 44] at its downstream end, wherein at least in the downstream portion of the burner, in which main fuel outlet, main oxidant outlet, pilot fuel outlet and auxiliary oxidant outlet are present, the secondary fuel conduit is arranged concentrically around the central main fuel lance, and wherein at least in said downstream portion of the burner the central main fuel lance, the pilot fuel conduit, the auxiliary oxidant conduit and the main oxidant conduit are surrounded fully or partially by the secondary fuel conduit [see Fig. 1 of Ihlenfield, where the pilot fuel conduit is provided in combination with Bunn].
With respect to claim 3 Ihlendield does not disclose a means for igniting the pilot fuel are present upstream the main fuel outlet inside the pilot fuel conduit and/or the auxiliary oxidant conduit.
Bunn discloses a means for igniting the pilot fuel [reference characters 32 and 34] are present upstream the main fuel outlet [reference character 46] inside the pilot fuel conduit.
It would have been obvious to one of ordinary skill in the art at the time of the filing date of the invention to modify the burner taught by the combination of Ihlenfield and Bunn by providing an igniter in the pilot fuel conduit, as taught by Bunn, in order to provide a means to ignite the pilot fuel and stabilize the main burner flame.
With respect to claim 9 the combination of Ihlenfield and Bunn disclose that the conduit end plane of the main oxidant conduit is recessed in upstream direction from conduit end plane of the secondary fuel conduit by a distance L3 [see annotated Fig. below].
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With respect to claim 15 the combination of Ihlenfield and Bunn discloses that the main oxidant conduit comprises bleed holes [reference character 57 of Ihenfield].
With respect to claim 18 the combination of Ihlenfield and Bunn discloses that the central mani fuel lance is an air assisted atomization nozzle [see column 3 lines 22-24 of Ihlenfield].
With respect to claim 21 the combination of Ihlenfield and Bunn disclose that during normal operation, the thermal output of the main fuel is 0-40% of the total thermal output of the burner, specifically, Ihlenfield discloses that the burner can be operated on gaseous fuel only [column 3 lines 33-57 of Ihlenfield], where the thermal output of the main fuel would be 0%.
With respect to claim 25 the combination of Ihlenfield and Bunn disclose a method for operating a burner (1) in accordance with claim 1, the method comprising the steps of i) starting the burner (1) using the pilot fuel, wherein the pilot fuel is a gaseous fuel [column 3 lines 15-21 of Bunn], ii) providing and igniting the main fuel [column 3 lines 23-34 of Bunn], wherein the main fuel is a liquid fuel [column 4 line 44 of Ihlenfield], particularly wherein the method additionally comprises further providing and igniting the secondary fuel, especially wherein the said secondary fuel is provided once it becomes available during an industrial process [column 3 lines 33-57].
With respect to claim 26 the combination of Ihlenfield and Bunn disclose that the method comprises a further step of continuing providing and burning the pilot fuel where required [note that column 3 lines 13-55 of Bunn do not disclose turning off the pilot light], particularly at low turndown ratios and/or to assist in combustion of hard to combust liquid fuels, to keep the flame of the main fuel stable.
Allowable Subject Matter
Claim 27 is allowed.
Claims 6-8, 10-14, 16-17, and 19-20 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
THIS ACTION IS MADE FINAL. Applicant is reminded of the extension of time policy as set forth in 37 CFR 1.136(a).
A shortened statutory period for reply to this final action is set to expire THREE MONTHS from the mailing date of this action. In the event a first reply is filed within TWO MONTHS of the mailing date of this final action and the advisory action is not mailed until after the end of the THREE-MONTH shortened statutory period, then the shortened statutory period will expire on the date the advisory action is mailed, and any nonprovisional extension fee (37 CFR 1.17(a)) pursuant to 37 CFR 1.136(a) will be calculated from the mailing date of the advisory action. In no event, however, will the statutory period for reply expire later than SIX MONTHS from the mailing date of this final action.
Any inquiry concerning this communication or earlier communications from the examiner should be directed to VIVEK K SHIRSAT whose telephone number is (571)272-3722. The examiner can normally be reached M-F 9:00AM-5:20AM.
Examiner interviews are available via telephone, in-person, and video conferencing using a USPTO supplied web-based collaboration tool. To schedule an interview, applicant is encouraged to use the USPTO Automated Interview Request (AIR) at http://www.uspto.gov/interviewpractice.
If attempts to reach the examiner by telephone are unsuccessful, the examiner’s supervisor, Steven B McAllister can be reached at 571-272-6785. The fax phone number for the organization where this application or proceeding is assigned is 571-273-8300.
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/VIVEK K SHIRSAT/Primary Examiner, Art Unit 3762
1 Although not explicitly disclosed as a “pilot fuel conduit” the fuel conduit disclosed by Bocci could be used to generate a pilot flame for ignition of the main fuel issued from the central liquid fuel lance.