Ex parte Ryham

Board of Patent Appeals and Interferences

May 23, 2001

08420730 (B.P.A.I. May. 23, 2001)

-1-
The opinion in support of the decision being
entered today was not written for publication
and is not binding precedent of the Board.
Paper No. 20
UNITED STATES PATENT AND TRADEMARK OFFICE
________________
BEFORE THE BOARD OF PATENT APPEALS
AND INTERFERENCES
________________
Ex parte ROLF C. RYHAM
________________
Appeal No. 1998-3168
Application No. 08/420,730
________________
ON BRIEF
________________
Before KIMLIN, WALTZ and DELMENDO, Administrative Patent
Judges.
KIMLIN, Administrative Patent Judge.
DECISION ON APPEAL
This is an appeal from the final rejection of claims 1,
5-15, 17-20, 23 and 27. Claims 2-4, 16, 21, 22 and 26, the
other
claims remaining in the present application, have been
objected to by the examiner. Claim 1 is illustrative:
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1. A method of producing steam having less sulfur-
containing noncondensible gases than steam produced by
flashing black liquor, including sulphur [sic] compounds,
directly into steam, comprising the steps of:
(a) passing hot black liquor, including sulphur [sic]
compounds, at a temperature of about 120-165EC from a digester
through a heat exchanger; and
(b) passing an evaporable liquid to be evaporated through
the heat exchanger into heat exchange contact with the hot
black liquor so that the evaporable liquid is heated so that
it is ultimately evaporated to produce steam having less
sulfur-containing noncondensible gases than steam produced by
flashing black liquor, including sulphur [sic] compounds,
directly into steam.
The examiner relies upon the following references as
evidence of obviousness:
Dean 2,029,360Feb. 4, 1936
Schlichtig 3,641,784 Feb. 15, 1972
Elmore et al. (Elmore) 4,897,157 Jan. 30, 1990
Appellant's claimed invention is directed to a method and
system for producing steam that has less sulfur-containing
noncondensible gases than steam produced by the flashing of
black liquor. The method entails passing hot black liquor
through a heat exchanger for heating an evaporable liquid,
i.e., water, that is ultimately evaporated to produce steam.
The produced steam, which has little, if any, sulfur-
containing noncondensible gases, can be used to treat
comminuted cellulosic fibers prior to the introduction of the
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fibers into a digester. In essence, rather than flashing the
black liquor to produce sulfur-containing steam, appellant's
method uses hot black liquor to heat a purer form of water,
i.e., water not containing sulfur, to produce a steam.
Appealed claims 1, 11-14, 15, 20 and 23 stand rejected
under 35 U.S.C. § 103 as being obvious over Elmore in view of
Dean. Claims 5-10, 17-19 and 27 stand rejected under
35 U.S.C. § 103 as being unpatentable over Elmore in view of
Dean and Schlichtig.
We have thoroughly reviewed each of appellant's arguments
for patentability, as well as the declaration evidence relied
upon in support thereof. However, we are in complete
agreement with the examiner that the claimed subject matter
would have been obvious to one of ordinary skill in the art
within the meaning of § 103 in view of the applied prior art.
Accordingly, we will sustain the examiner's rejections for the
reasons set forth in the Answer, which we incorporate herein,
and we add the following for emphasis only.
There is no dispute that Elmore produces multiple steam
streams by flashing black liquor for the purpose of recovering
heat energy in the system. There is also no dispute that Dean
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teaches a process for recovering heat energy by utilizing the
vapor stream from a digester to produce pure steam for uses
"such as the operation of evaporators, paper mill dryers and
also during the preheating period for the operation of
digesters" (page 1, column 1, lines 37-39). Accordingly,
based on the collective teachings of Elmore and Dean, we are
convinced that it would have been obvious for one of ordinary
skill in the art to modify the system of Elmore by using the
hot black liquor to form
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steam from non-sulfur containing water through the use of a
heat exchanger. We cannot agree more with the examiner's
rationale
that:
[I]f one is concerned with the recovery of
heat energy from the digester and producing
pure and clean steam for use in the paper
mill dryer, it would have been obvious to
modify the heat energy recovery and steam
generation of Elmore by using indirect heat
exchanger and fresh clean water as a source
of evaporable liquid inlet to produce clean
steam as taught by Dean [sentence bridging
pages 8 and 9 of Answer].
Since both Elmore and Dean are directed to paper milling
processes and are concerned with the efficient recovery of
heat energy, we do not agree with appellant that Dean is non-
analogous art with respect to the disclosure of Elmore and the
claimed invention.
Appellant asks at page 5 of the principal brief "what
would motivate one of ordinary skill in the art to act upon
the stream 60 which does contain sulfur compounds in Elmore et
al[.] so that it did not contain sulfur compounds?" We find
the motivation clearly spelled out in Dean, i.e., the
motivation to produce pure steam for the unit operations which
require it, namely, evaporators, paper mill dryers, and during
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the preheating period for the operation of digesters. This
motivation is expressly stated by Dean (page 1, column 1,
lines 36 et seq.).
Appellant contends at page 6 of the principal brief that
Dean is non-analogous prior art because "[n]ot only does the
disclosure of Dean apply solely to batch digesters, but the
disclosure of Dean applies to old obsolete batch digesters."
However, appellant's own specification states that the present
invention is applicable to continuous or batch digesters (page
2, lines 19-21).
Appellant also maintains that "[b]oth the disclosure of
Dean and other conventional batch digester recovery systems
are limited to the recovery of heat from vapor and none employ
the hot spent cooking liquids as does the present invention"
(page 7 of principal brief, last paragraph). However, it is
our view that appellant ascribes too narrow an interpretation
of Dean by one of ordinary skill in the art. In our view, one
of ordinary skill in the art would have understood Dean as
teaching the production of a pure form of steam from
sufficiently hot streams of a paper milling process, be they
liquid or vapor.
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Application No. 08/420,730
NCG is an acronym for non-condensible gas.1
-7-
Appellant relies upon the Declaration of Carl L. Elmore,
one of the inventors of the applied Elmore reference, as
evidence of nonobviousness. Mr. Elmore states at page 2 of
the Declaration that "I did not look upon the '157 patent as
including a method or apparatus for producing steam having
less NCG than steam produced by conventional black liquor
flashing." In response to this Declaration, the examiner1
withdrew a rejection under 35 U.S.C. § 102 over Elmore.
However, while the declarant states in the sentence bridging
pages 4 and 5 of the Declaration that "in 1995 it would have
been very desirable to be able to have a method of producing
steam from hot black liquor that contained relatively little
sulfur NCG, particularly for use in steaming incoming wood
chips," the Declaration fails to present any evidence or even
opinion that the claimed method of producing a purer form of
steam would have been nonobvious to one of ordinary skill in
the art, particularly in light of the Dean disclosure. The
declarant offers no opinion regarding how one of ordinary
skill in the art, at the time of filing the present
application, would have interpreted the disclosure of Dean.
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Consequently, we find that the Declaration is of little
probative value in rebutting the evidence of obviousness
presented by the examiner.
As for the examiner's § 103 rejection of claims 5-10, 17-
19 and 27 over the additional teaching of Schlichtig, we agree
with the examiner that it would have been prima facie obvious
for one of ordinary skill in the art to employ the claimed
inductor to improve the heat transfer efficiency in the heat
exchanger.
In conclusion, based on the foregoing and the reasons
well-stated by the examiner, the examiner's decision rejecting
the appealed claims is affirmed.
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No time period for taking any subsequent action in
connection with this appeal may be extended under 37 CFR
§ 1.136(a).
AFFIRMED
EDWARD C. KIMLIN )
Administrative Patent Judge )
)
)
)
)
THOMAS A. WALTZ ) BOARD OF PATENT
Administrative Patent Judge ) APPEALS AND
) INTERFERENCES
)
)
)
ROMULO H. DELMENDO )
Administrative Patent Judge )
ECK:clm
Appeal No. 1998-3168
Application No. 08/420,730
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