Borsig GmbH

Patent Trials and Appeals Board

Jul 27, 2021

2021000881 (P.T.A.B. Jul. 27, 2021)

UNITED STATES PATENT AND TRADEMARK OFFICE
UNITED STATES DEPARTMENT OF COMMERCE
United States Patent and Trademark Office
Address: COMMISSIONER FOR PATENTS
P.O. Box 1450
Alexandria, Virginia 22313-1450
www.uspto.gov
APPLICATION NO. FILING DATE FIRST NAMED INVENTOR ATTORNEY DOCKET NO. CONFIRMATION NO.
15/297,486 10/19/2016 Jan M¿GGENBURG 75619 8400
23872 7590 07/27/2021
MCGLEW & TUTTLE, PC
P.O. BOX 9227
SCARBOROUGH STATION
SCARBOROUGH, NY 10510-9227
EXAMINER
MALIK, RAHEENA REHMAN
ART UNIT PAPER NUMBER
3763
MAIL DATE DELIVERY MODE
07/27/2021 PAPER
Please find below and/or attached an Office communication concerning this application or proceeding.
The time period for reply, if any, is set in the attached communication.
PTOL-90A (Rev. 04/07)
UNITED STATES PATENT AND TRADEMARK OFFICE
BEFORE THE PATENT TRIAL AND APPEAL BOARD
Ex parte JAN MÜGGENBURG
Appeal 2021-000881
Application 15/297,486
Technology Center 3700
Before EDWARD A. BROWN, JEREMY M. PLENZLER, and
CARL M. DEFRANCO, Administrative Patent Judges.

DEFRANCO, Administrative Patent Judge.

DECISION ON APPEAL
STATEMENT OF THE CASE
Pursuant to 35 U.S.C. § 134(a), Appellant appeals from the
Examiner’s decision to reject claims 1–12 and 15–22.1 Claims 13 and 14 are
canceled. We have jurisdiction under 35 U.S.C. § 6(b). We reverse.

1 We use the word “Appellant” to refer to “applicant” as defined in 37
C.F.R. § 1.42(a). Appellant identifies the real party in interest as Borsig
GmbH. Appeal Br. 1.
Appeal 2021-000881
Application 15/297,486

2
CLAIMED SUBJECT MATTER
Of the claims on appeal, claims 1, 12, and 22 are independent. All
three independent claims are directed to a “heat exchanger.” Claim 1,
reproduced below, is illustrative of the claimed subject matter.
1. A heat exchanger comprising:
a cylindrical jacket;
a plurality of heat transfer tubes;
a centrally arranged bypass tube;
a gas inlet chamber tube plate cooperating with the
cylindrical jacket to form a gas inlet chamber;
a gas outlet chamber tube plate cooperating with the
cylindrical jacket to form a gas outlet chamber, the bypass tube
and the heat transfer tubes being held between the gas inlet
chamber tube plate and the gas outlet chamber tube plate,
wherein the gas inlet chamber tube plate and the gas outlet
chamber tube plate are connected to the cylindrical jacket to
form a jacket space therewithin, whereby the heat transfer tubes
and the bypass tube are enclosed and a coolant can be
introduced into the jacket space;
at least one inlet pipe connected to the cylindrical jacket
for introducing a coolant into the jacket space to a jacket side of
the heat transfer tubes;
at least one outlet pipe connected to the cylindrical jacket
for draining off a water/vapor mixture from the jacket space,
which is produced by indirect heat transfer via the jacket side of
the heat transfer tubes;
an inlet pipe arranged laterally or axially at the gas inlet
chamber in front of the tube plate in a gas flow direction for
introducing a hot process gas stream into the heat transfer tubes
and into the bypass tube on a gas inlet side of inlet chamber
tube plate;
a discharge pipe arranged laterally or axially at the gas
outlet chamber behind the tube plate in the gas flow direction
for draining off a mixture of the cooled process gas streams
Appeal 2021-000881
Application 15/297,486

3
from the heat transfer tubes and from the uncooled process gas
stream from the bypass tube on the gas outlet side of the outlet
chamber tube plate; and
a control device comprising a drive and a throttle valve
connected to the drive for setting a gas outlet temperature of the
heat exchanger to a certain temperature range by mixing the
cooled process gas streams from the heat transfer tubes with the
uncooled process gas stream from the bypass tube, the throttle
valve being arranged at an outlet end of the bypass tube, the
throttle valve being arranged in a valve housing, the drive being
arranged outside the heat exchanger, wherein a discharge rate
and a discharged quantity of the uncooled process gas stream
from the bypass tube is controlled by the throttle valve and is
adjustable via the drive of the control device, wherein the
throttle valve is manufactured from a material resistant
to high-temperature corrosion in a temperature range sensitive
to high-temperature corrosion and wherein the valve housing is
manufactured from a material not necessarily fully resistant to
high temperature corrosion, but operated at a temperature
outside of the range of high temperature corrosion and wherein
the valve housing is protected by an insulation against high
temperatures, the temperature range being around 500°C to
about 850°C, the material resistant to high-temperature
corrosion comprising a ceramic material.

Appeal Br. 43–44 (Claims App.) (emphases added).
EXAMINER’S REJECTIONS
Claims 1, 10–12, 19, and 22 stand rejected under 35 U.S.C. § 103 as
unpatentable over Jekerle (US 7,412,945 B2, iss. Aug. 19, 2008), Hernblom
(US 2011/0059335 A1, pub. Mar. 10, 2011), and Primdahl (US 5,852,990,
iss. Dec. 29, 1998).
Claims 2–9, 15–18, 20, and 21 stand rejected under 35 U.S.C. § 103
as unpatentable over Jekerle, Hernblom, Primdahl, and Von Kossak-
Glowczewski (US 2012/0305847 A1, pub. Dec. 6, 2012).
Appeal 2021-000881
Application 15/297,486

4
ANALYSIS
A. Obviousness Over Jekerle, Hernblom, and Primdahl
We begin with claim 1. The Examiner finds that Jekerle discloses
essentially all the components of the heat exchanger as recited by claim 1,
including the recited “throttle valve being arranged at an outlet end of the
bypass tube” in the heat exchanger. Final Act. 2–4 (mapping Jekerle’s
control stopper 12 to the recited “throttle valve” and Jekerle’s bypass pipe 4
to the recited “bypass tube”). The Examiner acknowledges, however, that
Jekerle lacks the claim recitation that “the throttle valve is manufactured
from a material resistant to high-temperature corrosion in a temperature
range sensitive to high temperature corrosion, the temperature range being
around 500°C to about 850°C, [and] the material resistant to high-
temperature corrosion comprising a ceramic material.” Id. at 4.
For supplying those missing limitations, the Examiner points to
Hernblom’s teaching of a heat exchanger tube that resists temperatures
“between 400 and 900° C,” and points to Primdahl’s teaching of a heat
exchanger nozzle made of “ceramic material.” Id. at 4–5 (citing Hernblom
¶ 96; Primdahl 2:23–30, Fig. 1). With those teachings in mind, the
Examiner determines that one skilled in the art would deem it obvious
to modify Jekerle’s throttle valve to be manufactured from a
material resistant to high-temperature corrosion being in a
temperature range of 500°C to 850°C as similarly taught . . . by
Hernblom and to comprise the material of a ceramic material as
taught by Primdahl in order to protect the throttle valve from
high temperature corrosion.

Id. at 5 (emphasis added). The Examiner advances essentially the same
findings and rationale in rejecting independent claims 12 and 22, which
recite limitations similar to claim 1. Id. at 6–11.
Appeal 2021-000881
Application 15/297,486

5
We see error in the Examiner’s reason for combining the teachings of
Hernblom and Primdahl with Jekerle. As Appellant correctly notes, Jekerle
“already solves the problem of preventing corrosion” of its control stopper
12 by providing that the stopper is cooled via cooling medium 32. Appeal
Br. 13–16 (citing Jekerle, 1:49–63, 2:5–8, 4:16–20). And, because the
purpose of Jekerle’s fluid-cooled stopper is to prevent corrosion, Appellant
explains, one skilled in the art would have no reason to look to either
Hernblom or Primdahl to perform that same job. Id. at 13, 16.
The record fully supports Appellant’s position. Jekerle explains that
existing stoppers and dampers have difficulty controlling the high thermal
load caused by the very hot plumes emanating from the outlet end of a heat
exchanger’s bypass tube. See Jekerle, 1:32–44. As such, Jekerle recognizes
the need “to create a control stopper that, on the one hand, is able to
withstand the high exhaust gas temperatures, and on the other hand, to avoid
the formation of hot plumes when the exhaust gases exit from the bypass
pipe outlet end.” Id. at 1:49–53. Jekerle’s solution provides that the stopper
be cooled by a cooling medium that, in turn, extends into the bypass pipe
such that the exhaust gas flows over the outer surface of the fluid-cooled
stopper. Id. at 1:54–63, Fig. 2. According to Jekerle, providing the stopper
with a cooling medium has the dual advantage that hot plumes are avoided
as the exhaust gases exit the bypass pipe and “thermal corrosion to the
stopper is avoided, and the functionality and life span of the control element
is significantly improved or increased, as the case may be.” Id. at 2:5–8.
Those disclosures by Jekerle show that the fluid-cooled stopper is
critical to the function of Jekerle’s heat exchanger. Thus, rather than leading
one skilled in the art to replace Jekerle’s fluid-cooled stopper with a ceramic
Appeal 2021-000881
Application 15/297,486

6
stopper, one skilled in the art more likely would avoid such a modification
due to the critical nature of the cooling medium not only in preventing hot
plumes at the bypass outlet but also in preventing thermal corrosion of the
stopper itself. As such, we are not persuaded that one skilled in the art
would have been led to the teachings of either Hernblom or Primdahl “in
order to protect [Jekerle’s] throttle valve from high temperature corrosion,”
as the Examiner posits, when Jekerle’s fluid-cooled stopper already achieves
that critical function. Thus, we do not sustain the Examiner’s rejection of
claim 1.
Independent claims 12 and 22 recite similar structure to claim 1. In
rejecting these claims, the Examiner relies on the same flawed reasoning to
combine Jekerle, Hernblom, and Primdahl as that discussed above with
respect to claim 1. See Final Act. 8, 11. Thus, for the same reasons we do
not sustain the Examiner’s rejection of claim 1, we do not sustain the
rejection of independent claims 12 and 22. Furthermore, claims 10, 11, 14,
and 19 depend from independent claims 1 and 12, and the Examiner’s
rejection of these dependent claims inherits the same flawed reasoning as
discussed with respect to the independent claims. Thus, we also do not
sustain the rejection of dependent claims 10, 11, 14, and 19.
B. Obviousness Over Jekerle, Hernblom, Primdahl, and Von Kossak-
Glowczewski
Claims 2–9, 15–18, 20, and 21 depend ultimately from either claim 1
or claim 12. See Appeal Br. 44–50 (Claims App.). The Examiner’s addition
of Von Kossak-Glowczewski to this obviousness rejection does not remedy
the deficiency discussed above with respect to the Examiner’s combination
of Jekerle, Hernblom, and Primdahl. See Final Act. 11–17. Thus, for the
same reason discussed above with respect to claims 1 and 12, we also do not
Appeal 2021-000881
Application 15/297,486

7
sustain the Examiner’s obviousness rejection of dependent claims 2–9, 15–
18, 20, and 21.
CONCLUSION
Claim(s)
Rejected
35 U.S.C. § Reference(s)/Basis Affirmed Reversed
1, 10–12,
19, 22
103 Jekerle, Hernblom,
Primdahl
1, 10–12, 19,
22
2–9, 15–18,
20, 21
103 Jekerle, Hernblom,
Primdahl, Von Kossak-
Glowczewski
2–9, 15–18,
20, 21
Overall
Outcome
1–12, 15–22
REVERSED