Ex parte Cameron

Board of Patent Appeals and Interferences

Jul 26, 2000

08512395 (B.P.A.I. Jul. 26, 2000)

1
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publication in a law journal and (2) is not binding precedent of the Board.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. 21
UNITED STATES PATENT AND TRADEMARK OFFICE
__________
BEFORE THE BOARD OF PATENT APPEALS
AND INTERFERENCES
__________
Ex parte GORDON M. CAMERON
__________
Appeal No. 1999-2643
Application 08/512,395
___________
ON BRIEF
___________
Before COHEN, FRANKFORT, and MCQUADE, Administrative Patent
Judges.
MCQUADE, Administrative Patent Judge.
DECISION ON APPEAL
Gordon M. Cameron appeals from the final rejection of
claims 1, 2 and 4. Claims 3, 5 through 8 and 15, the only
other claims pending in the application, stand withdrawn from
consideration pursuant to 37 CFR § 1.142(b).
The subject matter on appeal relates to “gas-to-gas heat
exchangers for use in sulphuric acid manufacturing plants”
Appeal No. 1999-2643
Application 08/512,395
2
(specification, page 1). Claim 1 is illustrative and reads as
follows:
1. A shell and tube, gas-to-gas heat exchanger for use
in the manufacture of sulphuric acid by the contact process
involving heat transfer between dry gases, said exchanger
comprising a shell having a first shell portion defining a
first shell space, a second shell portion defining a second
shell space and a third shell portion defining a third shell
space, said second shell space being located between said
first and said third shell spaces; an annular tube bundle
comprising a plurality of tubes within said shell and
extending longitudinally through said first shell space, said
second shell space and said third shell space and defining a
core space free of said tubes within said bundle and an
annular space free of tubes between said shell and said
annular bundle; said shell having a first gas conduit means
and a second gas conduit means; each of said tubes having a
tube gas input means and a tube gas output means and baffle
means;
the improvement wherein said first shell portion further
defines a first shell aperture in communication with said
first shell space and through which a first gas stream
operably passes; said second shell portion further defines a
second shell aperture in communication with said second shell
space and through which a second gas stream operably passes;
said third shell portion further defines a third shell
aperture in communication with said third shell space and
through which a third gas stream operably passes; said baffle
means so located within said first, said second and said third
shell spaces as to operatively direct said first gas, said
second gas and said third gas streams, within said first shell
space, said second shell space and said third shell space,
respectively, in radial flow across said tube bundle; wherein
said second shell space constitutes a chamber within which
said second gas stream comprises a mixture of said first gas
stream and said third gas stream.
Appeal No. 1999-2643
Application 08/512,395
Appealed claim 1 is a Jepson-type claim. Thus, the heat1
exchanger recited in its preamble is impliedly admitted to be
old in the art. See 37 CFR § 1.75(e) and MPEP § 2129. The
appellant has not challenged this implication.
3
The items relied upon by the examiner as evidence of
obviousness are:
Katterjohn, Jr. 3,859,735 Jan. 14,
1975
(Katterjohn)
Magari et al. 4,991,648 Feb. 12,
1991
(Magari)
The shell and tube, gas-to-gas heat exchanger for the
manufacture of sulphuric acid recited in the preamble of
appealed claim 1 (the admitted prior art).1
Claims 1, 2 and 4 stand rejected under 35 U.S.C. § 103 as
being unpatentable over the admitted prior art in view of
Katterjohn and Magari.
Reference is made to the appellant’s brief (Paper No. 19)
and to the examiner’s answer (Paper No. 20) for the respective
positions of the appellant and the examiner with regard to the
merits of this rejection.
Implicit in the examiner’s reliance on the preamble of
Jepson-type claim 1 as admitted prior art is the concession
Appeal No. 1999-2643
Application 08/512,395
4
that the heat exchanger encompassed by the admission fails to
respond
to the limitations in the claim defining the appellant’s
improvement. These deficiencies in the admitted prior art
find no cure in Katterjohn and Magari.
Katterjohn discloses a heat exchanger which functions as
a preheater for a clothes dryer or the like. This heat
exchanger/preheater 10 includes a shell housing 20, an air
intake chamber C at the bottom of the shell housing for1
receiving hot exhaust air from the dryer, an air discharge
chamber C at the top of the shell housing for discharging2
cooled exhaust air to the atmosphere, a heat exchange chamber
C between the air intake and discharge chambers, heat exchange
tubes 27 for feeding the exhaust air through the heat exchange
chamber from the intake chamber to the discharge chamber,
inlet orifice means O and O in the shell housing at the lower1 2
and upper ends of the heat exchange chamber C for taking in
ambient air, and an output passage P in the shell housing
intermediate the orifices O and O for discharging to the1 2
dryer ambient air which has been preheated through scrubbing
Appeal No. 1999-2643
Application 08/512,395
5
contact with the heat exchange tubes. According to
Katterjohn, this particular arrangement of elements promotes
maximum heat transfer efficiency (see column 5, line 55,
through column 6, line 63).
Magari discloses a prior art heat exchanger (see Figure
14) used in an acrylic acid reactor. As explained by Magari,
a plurality of reaction tubes (heat transfer tubes)
1 packed with a catalyst and disposed in parallel to
one another are fixed by upper and lower header
plates 2. A heat medium serving as shell side fluid
is introduced into a reactor shell 11 through an
inlet nozzle 3 at the lower portion of the reactor
shell 11, and after reaction heat has been
recovered, the heat medium is discharged through an
outlet nozzle 4 at the upper portion of the reactor
shell 11. At that time, in order to improve the
heat transfer performance of the heat medium, a
plurality of baffle plates 5 are disposed within the
reactor shell 11. The arrangement is such that raw
material gas formed by mixing heated fluid propylene
with air may flow into the reaction tubes 1 from the
above through a nozzle 6, and after acrylic acid has
been produced in the tubes 1 it is discharged
through a nozzle 7 [column 1, lines 32 through 49].
In one embodiment (see Figure 16), the prior art baffle plates
take the form of alternating annular and circular plates 5b,
5b’, which would appear to promote fluid flow radially
Appeal No. 1999-2643
Application 08/512,395
6
inwardly and outwardly relative to the array of heat exchange
tubes.
In rejecting claim 1 under 35 U.S.C. § 103, the examiner
concludes (see pages 4 and 5 in the answer) that it would have
been obvious at the time the invention was made to a person
having ordinary skill in the art to provide the admitted prior
art heat exchanger with (1) first, second and third shell
spaces and apertures of the sort recited in claim 1 in view of
Katterjohn and (2) baffle means within such shell spaces to
direct the gas streams therein in radial flow across the tube
bundle in view of Magari, all to improve the heat transfer
performance of the admitted prior art heat exchanger.
Obviousness cannot be established by combining the
teachings of the prior art to produce the claimed invention
absent some teaching or suggestion supporting the combination.
In re Fritch, 972 F.2d 1260, 1266, 23 USPQ2d 1780, 1784 (Fed.
Cir. 1992). In other words, under 35 U.S.C. § 103, the
teachings of references can be combined only if there is some
suggestion or incentive to do so. Id.
It goes without saying that in the heat exchanger art
optimum heat transfer efficiency is usually, if not always, a
Appeal No. 1999-2643
Application 08/512,395
7
prime consideration. Nonetheless, this general desire for
high performance does not justify the particular reference
combination proposed by the examiner which involves a
modification of the admitted prior art heat exchanger in view
of Katterjohn, and then a further modification of the initial
modification in view of Magari. Having carefully evaluated
the differences between the invention recited in claim 1 and
the applied prior art in light of the fair teachings and
suggestions of this prior art, we are satisfied that the
examiner has engaged in an impermissible
hindsight reconstruction of the invention by using the
appellant’s claims as a blueprint to selectively piece
together isolated disclosures in the prior art.
Accordingly, we shall not sustain the standing 35 U.S.C.
§ 103 rejection of claim 1, or of claims 2 and 4 which depend
therefrom, as being unpatentable over the admitted prior art
in view of Katterjohn and Magari.
The decision of the examiner is reversed.
REVERSED
Appeal No. 1999-2643
Application 08/512,395
8
IRWIN CHARLES COHEN )
Administrative Patent Judge )
)
)
) BOARD OF PATENT
)
CHARLES E. FRANKFORT ) APPEALS AND
Administrative Patent Judge )
) INTERFERENCES
)
)
)
)
JOHN P. MCQUADE )
Administrative Patent Judge )
JPM/kis
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