11680460 (B.P.A.I. May. 15, 2012)

Ex Parte Perry et al

Board of Patent Appeals and InterferencesMay 15, 2012

11680460 (B.P.A.I. May. 15, 2012)

UNITED STATES PATENT AND TRADEMARK OFFICE ____________ BEFORE THE BOARD OF PATENT APPEALS AND INTERFERENCES ____________ Ex parte DOUGLAS M. PERRY and JEFFREY T. RAFTER ____________ Appeal 2010-005630 Application 11/680,460 Technology Center 3700 ____________ Before JENNIFER D. BAHR, LINDA E. HORNER, and STEVEN D.A. McCARTHY, Administrative Patent Judges. HORNER, Administrative Patent Judge. DECISION ON APPEAL STATEMENT OF THE CASE Douglas M. Perry and Jeffrey T. Rafter (Appellants) seek our review under 35 U.S.C. § 134 of the Examiner’s decision rejecting claims 1-27. We have jurisdiction under 35 U.S.C. § 6(b). A hearing was held on May 10, 2012. We REVERSE. Appeal 2010-005630 Application 11/680,460 2 THE INVENTION Appellants’ claimed invention relates to a low-emission industrial burner, and in particular, to a burner and process for burning a combustible air/fuel mixture to produce a flame. Spec. 1, para. [0002]. Claim 1, reproduced below, is representative of the subject matter on appeal. 1. An air-fuel combustion system comprising an air/fuel transfer duct adapted to discharge an air-and- fuel mixture into a combustion chamber, an air-supply duct containing a first airflow channel in fluid communication with the air/fuel transfer duct, a separate second airflow channel in fluid communication with the air/fuel transfer duct, and a swirler located in the second airflow channel and configured to swirl combustion air flowing through the second airflow channel, and a fuel-supply duct coupled to the first airflow channel to discharge a first fuel stream generated from fuel flowing in the fuel-supply duct into combustion air flowing in the first airflow channel to produce a straight-line air/fuel mixture discharged from the first airflow channel into the air/fuel transfer duct and coupled to the second airflow channel to discharge a second fuel stream generated from fuel flowing in the fuel-supply duct into swirling combustion air flowing in the second airflow channel to produce a swirling air/fuel mixture discharged from the second airflow channel into the air/fuel transfer duct, wherein the air/fuel transfer duct is configured to provide means for conducting the straight-line air/fuel mixture discharged from the first airflow channel and the swirling air/fuel mixture discharged from the second airflow channel to a combustion chamber for combustion therein. Appeal 2010-005630 Application 11/680,460 3 THE EVIDENCE The Examiner relies upon the following evidence: Azuhata US 4,515,094 May 7, 1985 Flament US 4,919,611 Apr. 24, 1990 Toyoshima US 5,460,514 Oct. 24, 1995 Sarv ‘094 US 5,807,094 Sep. 15, 1998 Sarv ‘454 US 6,951,454 B2 Oct. 4, 2005 THE REJECTIONS Appellants seek review of the following rejections: 1. Claims 1-14 and 22-25 are rejected under 35 U.S.C. § 103(a) as unpatentable over Sarv ‘454 and Azuhata. 2. Claims 15, 17, 18, and 20 are rejected under 35 U.S.C. § 103(a) as unpatentable over Sarv ‘454, Azuhata, and Sarv ‘094. 3. Claims 16, 19, and 21 are rejected under 35 U.S.C. § 103(a) as unpatentable over Sarv ‘454, Azuhata, Sarv ‘094, and Toyoshima. 4. Claims 26 and 27 are rejected under 35 U.S.C. § 103(a) as unpatentable over Sarv ‘454, Azuhata, and Flament. ISSUES The issues presented by this appeal are: Would the burner of Sarv ‘454, as modified by the teaching of Azuhata, have an air/fuel transfer duct as called for in claims 1 and 22? Would operation of the burner of Sarv ‘454, as modified by the teaching of Azuhata, include the step of flowing a swirling air/fuel mixture alongside a non-swirling straight-line air/fuel mixture in an air/fuel transfer channel in a direction toward a combustion chamber to generate an air-and- Appeal 2010-005630 Application 11/680,460 4 fuel mixture flowing in the air/fuel transfer channel as called for in claim 24? ANALYSIS Rejection of claims 1-14 and 22-25 based on Sarv ‘454 and Azuhata Claim 1 recites “an air/fuel transfer duct adapted to discharge an air- and-fuel mixture into a combustion chamber” and “wherein the air/fuel transfer duct is configured to provide means for conducting the straight-line air/fuel mixture discharged from the first airflow channel and the swirling air/fuel mixture discharged from the second airflow channel to a combustion chamber for combustion therein.” Appellants argue that “[t]here is no structure [or equivalent] in either Sarv et al. or Azuhata et al. that corresponds to appellants’ air-fuel transfer channel.” App. Br. 6. The Examiner found that in the burner of Sarv ‘454 “the fuel mixture from [inner passageway] (57) mixes with the air from [outer passageway] (67) at the transfer location [burner outlet] (40) before the combustion zone (20).” Ans. 14. The Examiner determined that “when modified by Azuhata et al1, the transfer duct (40) will indeed transfer the two respective flows as claimed.” Id. We disagree with the Examiner’s finding that the furnace wall burner opening 40 of Sarv ‘454 is the “claimed air-fuel transfer duct.” In particular, the Examiner’s finding that the fuel mixture from passageway 57 mixes with 1 The Examiner states that “Azuhata is used to modify Sarv et al for the creation of the straight-line and swirling air/fuel mixtures.” Ans. 14. In particular, the proposed change is to add pulverized coal to the outer passageway 57 of Sarv to provide a swirling air/fuel mixture. Ans. 15. Appeal 2010-005630 Application 11/680,460 5 the air from passageway 67 prior to the combustion zone 20 is not supported by a preponderance of the evidence. Sarv ‘454 discloses a burner 10, a boundary wall of a furnace 12, and a furnace wall burner opening or port 40 defined by the burner throat 30. Col. 4, ll. 10-17; fig. 2. Sarv ‘454 describes that a first sleeve member 62 is concentrically spaced about a supply pipe 50 and injector 100 to form an inner annular passageway 57 for conveying a mixture of air and pulverized coal to the combustion zone 20, and a second sleeve member 63 is concentrically spaced about the first sleeve member 62 to form an outer annular passageway 67 for conveying secondary air 59 to the combustion zone. Col. 4, ll. 17-23; fig. 2. The gas injector element 100 is positioned in the center of the burner 10 in burner throat 30, and gaseous fuel 55 is injected from gas injector element 100 into combustion zone 20 and ignited. Col. 4, ll. 36-37 and 40-43. Sarv ‘454 discloses that “[t]ypically, a horizontally extending flame is generated at the gas injector element 100.” Col. 4, ll. 43-44. Because the flame extends from the injector element 100, which is disposed within the burner opening 40 at the burner throat 30, the combustion zone 20 includes the area in the burner throat 30 surrounding the injector element 100. As such, the air-fuel mixture from passageway 57 and the air from passageway 67 cannot be mixed prior to the combustion zone 20. Rather, the flows from each of these passageways are introduced directly into the combustion zone 20, without passing through any air/fuel transfer duct, as called for in claim 1. Appeal 2010-005630 Application 11/680,460 6 Appellants further argue that the Examiner’s stated reason to combine “is without basis in fact” and that to add fuel to passageway 67 “would significantly change the operation of Sarv et al.[, f]or example, changing from air flow to a flow of fuel and air would change shape of the flame, heat generated, NOx generation, etc.” App. Br. 8; Reply Br. 2. The goal of Sarv ‘454 is to “provide a gaseous fuel injector for a burner, which simultaneously produces short flames and low CO and NOx emissions via unique drilling patterns” which impart a swirling action to the gaseous fuel jets as they emerge from the discharge holes. Col. 2, ll. 34-41. Sarv ‘454 teaches that mixing of the gaseous fuel and air is improved as compared to non-swirling fuel jets, resulting in significant reductions in the flame length and CO emissions, and NOx emissions comparable to other single gas injectors. Col. 2, ll. 41-44. We agree with Appellants that adding fuel to the outer passageway of Sarv ‘454 would change the operation of Sarv’s burner by changing the shape of the flame. In light of this fact, the Examiner has not adequately explained why one of ordinary skill in the art would have been led to modify Sarv ‘454 with the teaching of Azuhata. For these reasons, we cannot sustain the Examiner’s rejection of claim 1, or dependent claims 2-14, as unpatentable over Sarv ‘454 and Azuhata. Independent claim 22 calls for “an air/fuel transfer duct adapted to discharge an air-and-fuel mixture into a combustion chamber,” “first-stage means for mixing a first fuel stream . . . with a laminar flow of air . . . to produce a non-swirling straight-line air/fuel mixture entering the air/fuel transfer duct,” and “second-stage means for mixing a second-fuel stream . . . Appeal 2010-005630 Application 11/680,460 7 with a swirling flow of air . . . to produce a swirling air/fuel mixture surrounding the non-swirling straight-line air/fuel mixture and entering the air/fuel transfer duct.” For the reasons stated supra, we find that Sarv ‘454, as modified by Azuhata, would not result in an air/fuel transfer duct that receives the straight-line and swirling air/fuel mixtures and discharges these mixtures into a combustion chamber. Further, we find that the Examiner has not adequately explained why one of ordinary skill in the art would have been led to modify Sarv ‘454 with the teaching of Azuhata. Accordingly, we cannot sustain the Examiner’s rejection of claim 22, or dependent claim 23, as unpatentable over Sarv ‘454 and Azuhata. Independent method claim 24 is directed to a process for generating an air-and-fuel mixture and includes the step of “flowing [a] swirling air/fuel mixture alongside [a] non-swirling straight-line air/fuel mixture in an air/fuel transfer channel in a direction toward a combustion chamber to generate and air-and-fuel mixture flowing in the air/fuel transfer channel.” For the reasons stated supra, we find that Sarv ‘454, as modified by Azuhata, would not result in a method including the step of generating an air-and fuel mixture from the straight-line and swirling air/fuel mixtures and flowing that air-and-fuel mixture in a direction towards a combustion chamber. Further, we find that the Examiner has not adequately explained why one of ordinary skill in the art would have been led to modify Sarv ‘454 with the teaching of Azuhata . Accordingly, we cannot sustain the Examiner’s rejection of claim 24, or dependent claim 25, as unpatentable over Sarv ‘454 and Azuhata. Appeal 2010-005630 Application 11/680,460 8 Rejection of claims 15, 17, 18, and 20 based on Sarv ‘454, Azuhata, and Sarv ‘094, claims 16, 19, and 21 based on Sarv ‘454, Azuhata, Sarv ‘094, and Toyoshima, and claims 26 and 27 based on Sarv ‘454, Azuhata, and Flament Claims 15-21 depend from independent claim 1 and claims 26 and 27 depend from independent claim 24. The Examiner’s rejections of these claims rely on the base combination of Sarv ‘454 and Azuhata and the determination that this combination would result in the air/fuel transfer duct of claim 1 and the flowing step of claim 24. Ans. 9-13. For the reasons discussed supra, we find the Examiner’s rejection of claims 1 and 24 deficient. The Examiner does not rely on Sarv ‘094, Toyoshima, or Flament to cure the deficiencies in the Sarv ‘454/Azuhata combination. Id. As such, the Examiner has not set forth a prima facie case of obviousness of dependent claims 15-21, 26, and 27. Accordingly, we cannot sustain the rejections of these claims. CONCLUSIONS The burner of Sarv ‘454, as modified by the teaching of Azuhata, would not have an air/fuel transfer duct as called for in claims 1 and 22. Operation of the burner of Sarv ‘454, as modified by the teaching of Azuhata, would not include the step of flowing a swirling air/fuel mixture alongside a non-swirling straight-line air/fuel mixture in an air/fuel transfer channel in a direction toward a combustion chamber to generate an air-and- fuel mixture flowing in the air/fuel transfer channel as called for in claim 24. Appeal 2010-005630 Application 11/680,460 9 DECISION The decision of the Examiner to reject claims 1-27 is REVERSED. REVERSED mls