Ex Parte MA

Board of Patent Appeals and Interferences

Jun 16, 2003

09463540 (B.P.A.I. Jun. 16, 2003)

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not written for publication and is not binding precedent of the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. 18
UNITED STATES PATENT AND TRADEMARK OFFICE
__________
BEFORE THE BOARD OF PATENT APPEALS
AND INTERFERENCES
__________
Ex parte THOMAS TSOI HEI MA
__________
Appeal No. 2003-0659
Application 09/463,540
___________
ON BRIEF
___________
Before McQUADE, WARREN and OWENS, Administrative Patent Judges.
OWENS, Administrative Patent Judge.
DECISION ON APPEAL
This appeal is from the final rejection of claims 1-16,
which are all of the claims in the application.
THE INVENTION
The appellant claims a method for purging a lean NOx trap,
and claims a lean burn engine and an exhaust gas flow treating
system having a device capable of carrying out that method.
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Application 09/463,540

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Claim 1, directed toward the method, is illustrative:
1. A method of purging a lean NOx trap that has a matrix
(16) of narrow flow passages and is arranged in the exhaust
system of a lean burn engine, the method comprising the steps of
providing a flow straightening matrix (12) of narrow flow
passages preceding the NOx trap matrix (16) and separated from
the NOx trap matrix by a narrow chamber (14), and periodically
injecting reducing gases in bursts into the narrow chamber (14),
each burst having sufficient mass and flow rate to fill the
narrow chamber (14) with the reducing gases and to displace the
exhaust gases previously present in the narrow chamber (14) into
the narrow flow passages of the flow straightening matrix (12)
and of the trap (16) without significantly mixing with the
exhaust gases previously present in the narrow chamber.
THE REFERENCES
Alcorn 4,912,776 Mar. 27, 1990
Martin et al. (Martin) 6,003,305 Dec. 21, 1999
(filed Sep. 2, 1997)
Hartweg et al. (Hartweg) 6,004,520 Dec. 21, 1999
(filed Dec. 12, 1996)
THE REJECTIONS
The claims stand rejected as follows: claims 1, 2 and 10
under 35 U.S.C. § 102(e) as anticipated by Alcorn or Hartweg, and
claims 1-16 under 35 U.S.C. § 103 as obvious over Hartweg in view
of Martin, or over Martin in view of Alcorn.
OPINION
We reverse the aforementioned rejections.
Rejection under 35 U.S.C. § 102(e) over Alcorn
“Anticipation requires that every limitation of the claim in
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Application 09/463,540

3
issue be disclosed, either expressly or under principles of
inherency, in a single prior art reference.” Corning Glass Works
v. Sumitomo Electric, 868 F.2d 1251, 1255-56, 9 USPQ2d 1962, 1965
(Fed. Cir. 1989).
The appellant’s method claim (1) requires a step of
periodically injecting reducing gases in bursts into a narrow
chamber, each burst having sufficient mass and flow rate to fill
the narrow chamber with reducing gases and to displace the
exhaust gases previously present in the narrow chamber without
significantly mixing with those exhaust gases. The appellants’
engine claims (2-9) and claims (10-16) to a system for treating
exhaust gases require a device which is capable of carrying out
that method step.
Alcorn discloses a method and apparatus for removing
nitrogen oxides from a gas stream which can be exhaust gas from
an internal combustion engine (col. 1, lines 23-29). The
apparatus includes two catalytic reactors in series, the first
for oxidizing NO to NO2 and the second for reducing NO2 with
ammonia which is introduced between the reactors (col. 3,
lines 27-31; col. 5, lines 10-26; figure 1). Alcorn teaches that
“ammonia is added to the gas stream through the perforated
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Application 09/463,540

4
tube 22, and the gas stream is thoroughly mixed” (col. 5,
lines 21-23).
The examiner argues that Alcorn discloses periodically
injecting reducing gases in bursts into a narrow chamber (answer,
page 3). Alcorn discloses a space (5) between the catalyst
carriers (13 and 14), and teaches that in this space reducing gas
(ammonia) is added to the gas stream (col. 5, lines 1-4; col. 5,
lines 21-22; figure 1). Alcorn, however, does not disclose that
the space is narrow or that the reducing gas is periodically
injected in bursts.
The examiner argues that Alcorn’s reducing gas displaces the
exhaust gases previously present in the space between the
catalyst carriers without significantly mixing with the exhaust
gases previously present in that space (answer, pages 3-4). This
interpretation of Alcorn is incorrect. What Alcorn teaches is
that the reducing gas is added to the gas stream through a
perforated tube and the gas stream is thoroughly mixed (col. 5,
lines 21-23).
The examiner argues that Alcorn’s injected reducing gas must
be at a higher pressure than the exhaust gas and that, therefore,
the reducing gas displaces the exhaust gas and continues to
expand to fill the space between the catalyst carriers (answer,
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5
page 9). Alcorn’s teaching that the reducing gas and the exhaust
gas are thoroughly mixed in the space between the catalyst
carriers (col. 5, lines 21-23) indicates that the examiner’s
reasoning is incorrect.
The examiner, therefore, has not carried the burden of
establishing a prima facie case of anticipation over Alcorn of
the invention claimed in any of the appellant’s claims.
Rejection under 35 U.S.C. § 102(e) over Hartweg
Hartweg discloses a device for reducing pollutants in
internal combustion engine exhaust gas (col. 1, lines 7-20). “By
adding reducing agent at a point after which the catalyst no
longer has any catalytic effect with respect [to] at least one of
the pollutants, the reduction of pollutants, particularly of
nitrogen oxides, can be increased to more than 40%” (col. 1,
lines 42-46). In one embodiment there are three catalyst
segments, the first two being separated by space 8 and the second
two being separated by space 8' (figure 3). Reducing agent is
introduced through a nozzle ring into space 8 and through an
atomizing nozzle into space 8' (col. 3, lines 36-41). Hartweg
teaches that “[t]he reducing agent flows into the respective
space 8 and 8' and mixes with the already partially purified
exhaust gas. The space 8 and 8' can therefore also be regarded
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as a sort of mixing chamber” (col. 3, lines 42-45).
The examiner argues that Hartweg’s chambers 8 and 8' are
narrow and that Hartweg periodically injects reducing gases in
bursts into these chambers (answer, page 4). Hartweg, however,
does not disclose that spaces 8 and 8' are narrow or that the
reducing agent is injected in bursts. Hartweg merely discloses
is that the reducing agent flows into spaces 8 and 8' (col. 3,
line 42).
The examiner argues that Hartweg’s reducing agent fills
spaces 8 and 8' and displaces the exhaust gases previously
present in those spaces without significantly mixing with the
exhaust gases (answer, pages 4 and 9). Hartweg’s teaching that
“[t]he reducing agent flows into the respective space 8 and 8'
and mixes with the already partially purified exhaust gas”
(col. 3, lines 42-43) indicates that the examiner’s
interpretation of the reference is incorrect.
Thus, the examiner has not established a prima facie case of
anticipation by Hartweg of the invention claimed in any of the
appellant’s claims.
Rejection under 35 U.S.C. § 103
over Martin in view of Alcorn
Martin discloses a flameless thermal oxidizer for
Appeal No. 2003-0659
Application 09/463,540

1 Martin’s supplemental fuel stream (5) and reductant
stream (7) are different streams (col. 10, lines 42-43; col. 11,
lines 5-6).
7
simultaneously reducing the concentrations of soot and oxides of
nitrogen in internal combustion engine exhaust (col. 5, lines 29-
32 and 45-48). The thermal oxidizer (10a) includes a reductant
delivery system (148) for injecting a reductant stream (7) into a
process stream (9) which contains exhaust gas (col. 8, lines 12-
17; col. 11, lines 4-6). The reductant preferably is injected
upstream of a matrix (14a), which is a bed of solid, heat
resistant media, to enable the reductant to be heated by the
matrix and to enhance mixing (col. 8, lines 25-26; col. 11,
lines 6-8). The reductant also can be injected directly into the
matrix, or can be combined with an air stream (4), fuel
stream (5) or hot gas stream (6), each of which is a component of
the process stream (col. 11, lines 9-14; figure 1).
The examiner argues that Martin discloses “periodically
injecting reducing gases in bursts into the narrow chamber (88)”
(answer page 6). Martin calls chamber 88 a fuel vaporization
chamber and discloses spraying supplemental fuel into that
chamber (col. 10, lines 38-53). Even if the supplemental fuel
can be considered a reducing gas,1 Martin does not disclose
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periodically injecting the supplemental fuel in bursts into the
chamber and does not disclose that the chamber is narrow.
The examiner argues that Martin discloses that chamber 88 is
filled with reducing gas which displaces the exhaust gases
previously present in the chamber without significantly mixing
with those exhaust gases (answer, pages 6-7 and 9). This
argument is based upon an incorrect interpretation of the
reference. Chamber 88 is a fuel vaporization chamber which
supplies vaporized supplemental fuel for mixing with the process
stream containing exhaust gas (col. 10, lines 41-43; figure 11).
Martin does not disclose that chamber 88 ever contains exhaust
gas. Moreover, as discussed above, Martin teaches that his
reductant gas mixes with the exhaust gas.
The examiner relies upon Alcorn only for a disclosure of a
flow straightening matrix (answer, pages 7-8), and not for any
disclosure which remedies the above-discussed deficiency in
Martin.
Accordingly, we conclude that the examiner has not carried
the burden of establishing a prima facie case of obviousness of
the invention claimed in any of the appellant’s claims over the
combined teachings of Martin and Alcorn.
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Rejection under 35 U.S.C. § 103
over Hartweg in view of Martin
The examiner argues that Hartweg and Martin disclose the
step and device recited in the appellant’s claims for
periodically injecting reducing gases (answer, pages 4-6). This
argument is not well taken for the reasons given above regarding
the rejection under 35 U.S.C. § 102(e) over Hartweg and the
rejection under 35 U.S.C. § 103 over Martin in view of Alcorn.
Thus, we conclude that the examiner has not established a
prima facie case of obviousness of the invention claimed in any
of the appellant’s claims over the combined teachings of Hartweg
and Martin.
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DECISION
The rejections of claims 1, 2 and 10 under 35 U.S.C.
§ 102(e) as anticipated by Alcorn or Hartweg, and claims 1-16
under 35 U.S.C. § 103 as obvious over Hartweg in view of Martin,
or over Martin in view of Alcorn, are reversed.
REVERSED
)
JOHN P. McQUADE )
Administrative Patent Judge )
)
)
) BOARD OF PATENT
CHARLES F. WARREN )
Administrative Patent Judge ) APPEALS AND
)
) INTERFERENCES
)
TERRY J. OWENS )
Administrative Patent Judge )
TJO/ki
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