Ex parte Klobucar

Board of Patent Appeals and Interferences

Jun 29, 2000

08854516 (B.P.A.I. Jun. 29, 2000)

THIS OPINION WAS NOT WRITTEN FOR PUBLICATION
The opinion in support of the decision being entered today (1) was not written for publication in a law journal and (2) is
not binding precedent of the Board.
Paper No. 14
UNITED STATES PATENT AND TRADEMARK OFFICE
____________
BEFORE THE BOARD OF PATENT APPEALS
AND INTERFERENCES
____________
Ex parte JOSEPH M. KLOBUCAR
____________
Appeal No. 1999-1738
Application No. 08/854,516
____________
ON BRIEF
____________
Before McCANDLISH, Senior Administrative Patent Judge, COHEN and BAHR, Administrative
Patent Judges.
BAHR, Administrative Patent Judge.
DECISION ON APPEAL
This is a decision on appeal from the examiner's final rejection of claims 1, 5 and 6.
Claims 2-4, the only other claims remaining in this application, stand allowed.
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Application No. 08/854,516
BACKGROUND
The appellant's invention relates to a method of rapidly cooling a regenerative thermal
oxidizer. An understanding of the invention can be derived from a reading of exemplary claim
1, which appears in the appendix to the appellant's brief.
The prior art references of record relied upon by the examiner in rejecting the appealed
claims are:
Gross et al. (Gross) 5,101,741 Apr. 7, 1992
Houston 5,417,927 May 23, 1995
Klobucar et al. (Klobucar) 5,538,420 Jul. 23, 1996
The following rejections stand before us for review.
1. Claims 1, 5 and 6 stand rejected under 35 U.S.C. ß 103 as being unpatentable over
Houston.
2. Claims 1, 5 and 6 stand rejected under 35 U.S.C. ß 103 as being unpatentable over
Gross.
3. Claims 1, 5 and 6 stand rejected under 35 U.S.C. ß 103 as being unpatentable over
Klobucar.
Reference is made to the main and reply briefs (Paper Nos. 9 and 11) and the answer
(Paper No. 10) for the respective positions of the appellant and the examiner with regard to the
merits of these rejections.
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Application No. 08/854,516
OPINION
In reaching our decision in this appeal, we have given careful consideration to the
appellant's specification and claims, to the applied prior art references, and to the respective
positions articulated by the appellant and the examiner. For the reasons which follow, we
cannot sustain any of the examiner's rejections.
Each of Houston, Gross and Klobucar discloses a regenerative thermal oxidizer or
incinerator comprising a combustion chamber and at least two, but preferably three, heat
exchangers (or regenerators) in communication with the combustion chamber, each of the heat
exchangers having a flow valve or separate inlet and outlet flow valves for selectively
communicating the regenerator with either a source of impure air to be cleaned or a clean air
discharge stack or a source of purge air (which may be either recycled air from the clean air
discharge or a separate source of clean air). The valves are controlled such that, at any given
time, one of the heat exchangers acts as an inlet heat exchanger for delivering impure air to the
combustion chamber, a second heat exchanger acts as an outlet heat exchanger for delivering
cleaned air from the combustion chamber to the discharge stack and the purge air passes
through the third heat exchanger into the combustion chamber and out through the outlet heat
exchanger. At predetermined intervals, the positions of the valves are altered such that the
roles of the heat exchangers are sequentially interchanged.
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Application No. 08/854,516
Houston further discloses a fuel gas supply line 36 connected to the impure gas inlet 15
by a line 57 and connected directly to the combustion chamber 25 by a line 56. A temperature
sensor 103 for monitoring the temperature of the combustion chamber controls a fuel shut-off
valve 100 to adjust the flow of fuel in accordance with the temperature of the combustion
chamber. Contrary to the examiner's assertion on page 3 of the answer, the temperature
sensor 103 is not disclosed as controlling cyclic operation of the valves in conduits 61-68 and
71-73. During the first part of a cycle interval, a valve 54 in the line 57 remains open so that
fuel is mixed with the impure air prior to its entry into the combustion chamber, thereby
improving the destruction efficiency of the oxidizer. The valve 54 is closed by a control 52
during the last 1 to 19% of the cycle interval to minimize the impurity in the inlet heat
exchanger (regenerator) during this time, thereby minimizing the impurity in the cleaned air
passing through that same heat exchanger when it becomes an outlet heat exchanger during a
subsequent cycle interval. If necessary or desired for a particular process, a valve 53 in the
line 56 can be opened during the portion of the cycle interval in which the valve 54 is closed to
supply fuel directly to the combustion chamber.
The disclosures of Gross and Klobucar are both directed to cleaning or bake-out cycles
in which extremely hot air is passed through the heat exchangers to bake-out any residues
accumulating therein. Gross achieves this by providing an inlet manifold isolation valve 48 in
the dirty air inlet manifold 38 and a valve 46 in an alternate inlet line 44. During normal
Appeal No. 1999-1738 Page 5
Application No. 08/854,516
operation, the valve 46 is closed and the valve 48 is open so that dirty air is delivered through
the heat exchanger 24, 26 or 28 which is then acting as the inlet heat exchanger to the
combustion chamber 22 and then passed out through the outlet heat exchanger. During a
cleaning cycle, the valve 48 is closed, thereby cutting off delivery of dirty air to the inlet
manifold 38 and the valve 46 is opened to deliver the dirty air directly to the combustion
chamber 22 via the alternate inlet line 44. Consequently, the air passing through the system is
raised to an unusually high temperature. The inlet and outlet valves 34, 36 of the heat
exchangers continue to cycle during the cleaning cycle (column 3, lines 65-66). The high
temperature air passes outwardly through the heat exchangers 24, 26 and 28 and through the
valves 34, 36 as they are cyclically opened, baking-out or oxidizing dried or condensed fluids
along the way. Klobucar, on the other hand, provides a separate air source 56 which is passed
through a burner 54 and then delivered to an inlet branch 32 leading to a heat exchanger 24,
26, 28. This hot air passes through the inlet heat exchanger, into the combustion chamber and
out through the outlet heat exchanger to bake-out or oxidize deposits therein.
As apparently recognized by the examiner, none of the references, Houston, Gross and
Klobucar, applied in rejecting the claims mentions a cool-down procedure for the incinerator or
oxidizer or discloses a step of increasing the cycle time of the open inlet and outlet valves to
rapidly cool the regenerative thermal oxidizer as required by independent claim 1 and claims 5
and 6 which depend from claim 1. Nevertheless, the examiner points out that "[t]he prior art
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Application No. 08/854,516
references are capable of increasing the cycle time as one desires" and asserts that it would
have been obvious to operate the inlet and outlet valves of any of Houston, Gross and Klobucar
in the manner claimed in order to efficiently cool the regenerative thermal oxidizer (answer,
pages 3-5).
Rejections based on 35 U.S.C. ß 103 must rest on a factual basis. In making such a
rejection, the examiner has the initial duty of supplying the requisite factual basis and may not,
because of doubts that the invention is patentable, resort to speculation, unfounded assumptions
or hindsight reconstruction to supply deficiencies in the factual basis. In re Warner, 379 F.2d
1011, 1017, 154 USPQ 173, 178 (CCPA 1967), cert. denied, 389 U.S. 1057 (1968).
While the examiner may be correct that the prior art apparatus is capable of increasing
the cycle time as desired, none of the applied references teaches or suggests a method of
operation in this manner. The mere fact that the prior art could be so modified would not have
made the modification obvious unless the prior art suggested the desirability of the modification.
See In re Mills, 916 F.2d 680, 682, 16 USPQ2d 1430, 1432 (Fed. Cir. 1990); In re Gordon,
733 F.2d 900, 902, 221 USPQ 1125, 1127 (Fed. Cir. 1984). In this instance, the examiner
has adduced no evidence that one of ordinary skill in the art would have appreciated that
increasing the cycle time of the heat exchanger inlet/outlet valves would improve the rate of
cool-down of the regenerator or that such a technique was known in the art at the time of the
appellant's invention for rapid cool-down of a regenerative thermal oxidizer. Therefore, it
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Application No. 08/854,516
appears to us that the examiner has impermissibly resorted to speculation or hindsight
reconstruction in rejecting the appellant's claims.
Accordingly, we cannot sustain any of the examiner's rejections of claims 1, 5 and 6
under 35 U.S.C. ß 103 as being unpatentable over any of Houston, Gross and Klobucar.
CONCLUSION
To summarize, the decision of the examiner to reject claims 1, 5 and 6 under 35 U.S.C.
ß 103 is reversed.
REVERSED
HARRISON E. McCANDLISH )
Senior Administrative Patent Judge )
)
)
)
) BOARD OF PATENT
IRWIN CHARLES COHEN ) APPEALS
Administrative Patent Judge ) AND
) INTERFERENCES
)
)
)
JENNIFER D. BAHR )
Administrative Patent Judge )
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Application No. 08/854,516
jdb/ki
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Application No. 08/854,516
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