WACKER CHEMIE AG

Patent Trials and Appeals Board

Jul 16, 2020

2019004817 (P.T.A.B. Jul. 16, 2020)

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.
14/889,347 11/05/2015 Simon PEDRON WASN0229PUSA 6544
22045 7590 07/16/2020
Brooks Kushman
1000 Town Center
22nd Floor
Southfield, MI 48075
EXAMINER
LEUNG, JENNIFER A
ART UNIT PAPER NUMBER
1774
NOTIFICATION DATE DELIVERY MODE
07/16/2020 ELECTRONIC
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.
Notice of the Office communication was sent electronically on above-indicated "Notification Date" to the
following e-mail address(es):
docketing@brookskushman.com
kdilucia@brookskushman.com
PTOL-90A (Rev. 04/07)

UNITED STATES PATENT AND TRADEMARK OFFICE
____________
BEFORE THE PATENT TRIAL AND APPEAL BOARD
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Ex parte SIMON PEDRON and GERHARD FORSTPOINTNER
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Appeal 2019-004817
Application 14/889,347
Technology Center 1700
____________
Before CHRISTOPHER C. KENNEDY, DEBRA L. DENNETT, and
JANE E. INGLESE Administrative Patent Judges.

DENNETT, Administrative Patent Judge.
DECISION ON APPEAL1
STATEMENT OF THE CASE
Pursuant to 35 U.S.C. § 134(a), Appellant2 appeals from the
Examiner’s decision to reject claims 20–35 of Application 14/889,347,
which constitute all the claims pending in this application. We have
jurisdiction under 35 U.S.C. § 6(b).

1 In our Decision, we refer to the Specification (“Spec.”) of Application No.
14/889,347 filed Nov. 5, 2015; the Final Office Action dated July 6, 2018
(“Final Act.”); the Advisory Action dated Oct. 9, 2018 (“Adv. Act.); the
Appeal Brief filed Feb. 4, 2019 (“Appeal Br.”); the Examiner’s Answer
dated Apr. 2, 2019 (“Ans.”); and the Reply Brief filed May 30, 2019 (“Reply
Br.”).
2 We use the word “Appellant” to refer to “applicant” as defined in 37
C.F.R. § 1.42. Appellant identifies the real party in interest as Wacker
Chemie AG. Appeal Br. 1.
Appeal 2019-004817
Application 14/889,347
2
For the reasons set forth below, we REVERSE.
The subject matter of the invention relates to fluidized bed reactors
and a method for producing granular polysilicon. Spec. 1, ll. 5–6.
Polysilicon granules produced in a fluidized bed reactor have bulk material
properties and can be used directly as a raw material. Spec. 1, ll. 14–16, 19.
According to the Specification, pressure conditions varying with time and
locality in fluidized beds cause fluctuations of the gas mass streams that are
fed, leading to instabilities in the chemical process and in the temperature
distribution. Spec. 3, ll. 21–28. The openings in a conventional gas
distributor plate via which all gas mass streams can be fed do not have a
sufficient pressure drop for distributing the respective mass streams in a
uniform manner with respect to time and locality. Spec. 3, ll. 34–4, ll. 2.
Applicant accomplishes a uniform distribution of gas mass streams
fed to a fluidized bed over time and all inlet openings via Laval nozzles,
preferably operated at a supercritical pressure ratio. Spec. 7, ll. 32–36. A
Laval nozzle is a flow element having an initially convergent and
subsequently divergent cross section, wherein the transition from one part to
the other part proceeds gradually. Spec. 5, ll. 14–17.
Claim 20, reproduced below from the Claims Appendix of the Appeal
Brief, illustrates the claimed subject matter:
20. In a fluidized bed reactor for producing granular
polysilicon, having an inner reactor tube for a fluidized bed of
granular polysilicon, the inner reactor tube having a reactor
base with openings for entry of fluidizing gas and reaction gas,
a heater for heating the fluidized bed of polysilicon, a silicon
particle feed, an opening above the fluidized bed for removing
offgas, and an opening in the inner reactor tube for removing a
granular silicon product, the improvement comprising:
Appeal 2019-004817
Application 14/889,347
3
at least two reaction gas openings in the reactor base,
each of the at least two reaction gas openings fed by a Laval
nozzle positioned outside of the reactor tube and upstream of
the at least two reaction gas openings, the Laval nozzle suitable
for expanding supercritically at least one mass stream of
reaction gas, the at least two reaction gas openings comprising a
gas distributor, a valve, a hole in the reactor base, or a nozzle,
wherein the intake pressure of the Laval nozzle is controlled by
gas quantity regulation.
REFERENCES
The Examiner relies on the following references in rejecting the
claims:
Name Reference Date
Schmit US 5,489,166 Feb. 6, 1996
Hertlein et al.
(“Hertlein”)
US 2008/0241046 A1 Oct. 2, 2008
REJECTIONS
The Examiner maintains the rejection of claims 20–35 under 35
U.S.C. § 1033 as obvious over Hertlein in view of Schmit. Final Act. 3–11.
DISCUSSION
Having considered the respective positions advanced by the Examiner
and Appellant in light of the record before us, we reverse the Examiner’s
rejections based on arguments presented by Appellant.
With respect to all of the claims, the Examiner finds that Hertlein
discloses the fluidized bed reactor and related limitations recited in claim 20.

3 Because this application was filed after the March 16, 2013, effective date
of the America Invents Act, we refer to the AIA version of the statute.

Appeal 2019-004817
Application 14/889,347
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Final Act. 3–5, 8–11. The Examiner finds that Hertlein does not disclose
that each of the at least two reaction gas openings is fed by a Laval nozzle
positioned outside the reactor tube and upstream of the reaction gas
openings. Id. at 4. The Examiner finds that Schmit teaches a Laval nozzle
situated upstream of openings. Id. at 5. The Examiner determines
It would have been obvious to one of ordinary skill in the art
before the effective filing date of the claimed invention to
provide a Laval nozzle upstream of each of the [at] least two
reaction gas openings in the reactor of Hertlein et al., on the basis
of suitability for the intended use thereof, because the at least two
reaction gas openings could then be supplied with reaction gas
by a supersonic flow through the Laval nozzle, which would
make it possible to fix the gas flow rate at a defined value, as
taught by Schmit.
Id.; see also Ans. 11.
Hertlein discloses a fluidized bed reactor for producing granular
polysilicon in which a gas or gas mixture containing silicon is fed through
the fluidized bed, depositing elementary silicon on all hot surfaces to grow
silicon particles. Hertlein ¶¶ 1, 4. Hertlein teaches a problem in such
devices is deposition of silicon on the hot reactor surfaces such as the reactor
walls, resulting in thermo-mechanical loading of the reactor and reactor
outages. Id. ¶ 4. Hertlein teaches use of a fluidizing gas, a reaction gas
comprising a high proportion of a gaseous silicon compound, as well as a
“wall-shielding” gas comprising 99.5 to 95 mol.% hydrogen and 0.5 to 5
mol.% gaseous silicon compound. Id. ¶¶ 20, 24. Hertlein’s wall-shielding
gas is present on the surface of the reactor, provided in the region of the
reactor surfaces. Id.
Schmit, which relates to removing granular or pulverulent solid
residues from a gas purification installation, describes creating overpressure
Appeal 2019-004817
Application 14/889,347
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in a closed vessel with two Laval nozzles, one between the gas supply
source and fluidization surface and the other in the gas removal pipeline.
Schmit col. 1, ll. 7–11; col. 4, ll. 33–37. Schmit teaches the fluidization
device is supplied with gas preferably by a supersonic flow through a Laval
nozzle. Id. col. 7, ll.7–10.
During examination, the Examiner bears the initial burden of
establishing a prima facie case of obviousness. In re Oetiker, 977 F.2d
1443, 1445 (Fed. Cir. 1992). “[R]ejections on obviousness grounds cannot
be sustained by mere conclusory statements; instead, there must be some
articulated reasoning with some rational underpinning to support the legal
conclusion of obviousness.” KSR Int’l v. Teleflex Inc., 550 U.S. 398, 418
(2007) (quoting In re Kahn, 441 F.3d 977, 988 (Fed. Cir. 2006)); see also,
Ball Aerosol and Specialty Container, Inc. v. Ltd. Brands, Inc., 555 F.3d
984, 993 (Fed. Cir. 2009) (“[T]he analysis that ‘should be made explicit’
refers not to the teachings in the prior art of a motivation to combine, but to
the court’s analysis.”). “Obviousness requires more than a mere showing
that the prior art includes separate references covering each separate
limitation in a claim under examination.” Unigene Labs., Inc. v. Apotex,
Inc., 655 F.3d 1352, 1360 (Fed. Cir. 2011). “Rather, obviousness requires
the additional showing that a person of ordinary skill at the time of the
invention would have selected and combined those prior art elements in the
normal course of research and development to yield the claimed invention.”
Id.
While the individual elements of the claims may appear in the
individual references, we discern no motivation to combine the references in
the manner suggested by the Examiner.
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Application 14/889,347
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Specifically, the Examiner has not convincingly explained why one
skilled in the art would modify Hertlein’s device, which minimizes wall
deposition of silicon by flow of a wall-shielding gas that blankets the walls,
by employing Schmit’s Laval nozzle to inject reaction gas at supersonic
flow. See Appeal Br. 5.
As Appellant explains, Hertlein desires inhomogeneous distribution of
gas in the reactor, so that gas along the walls of the reactor is 99.5 to 95
mol.% hydrogen, and 0.5 to 5 mol.% gaseous silicon compound. Reply Br.
8–9; see also Hertlein ¶ 12. The gas in the reaction space, in contrast, must
have a much higher silicon content in order to deposit silicon onto silicon
seeds. Hertlein ¶ 20. The Examiner fails to explain why one of ordinary
skill in the art would provide reaction gas to Hertlein at supersonic flow via
Laval nozzles, given that the “predictable result” would be homogenization
of gases in the reactor, defeating Hertlein’s intended purpose. See DePuy
Spine, Inc. v. Medtronic Sofamor Danek, Inc., 567 F.3d 1314, 1326 (Fed.
Cir. 2009) (“[T]he ‘predictable result’ discussed in KSR refers not only to
the expectation that prior art elements are capable of being physically
combined, but also that the combination would have worked for its intended
purpose.”).
We are persuaded that the Examiner has not provided sufficient
reasons to support the position that Hertlein and Schmit may be combined in
a manner that would render the claimed subject matter obvious. We do not
sustain the rejection of claims 20–35 as obvious over Hertlein in view of
Schmit.
DECISION SUMMARY
In summary:
Appeal 2019-004817
Application 14/889,347
7
Claims
Rejected
35 U.S.C.
§
Reference(s)/Basis Affirmed Reversed
20–35 103 Hertlein, Schmit 20–35
REVERSED