U.S. patent application number 11/891299 was filed with the patent office on 2008-01-31 for window device, diagnosis system for combustion processes, and combustion chamber.
This patent application is currently assigned to Deutsches Zentrum fuer Luft-und Raumfahrt e.V.. Invention is credited to Claus Wahl.
Application Number | 20080022992 11/891299 |
Document ID | / |
Family ID | 36095856 |
Filed Date | 2008-01-31 |
United States Patent
Application |
20080022992 |
Kind Code |
A1 |
Wahl; Claus |
January 31, 2008 |
Window device, diagnosis system for combustion processes, and
combustion chamber
Abstract
A window device for a space laden with carbon-containing
particles, in particular, for a combustion space, comprising at
least one optically transparent window element, is proposed, the at
least one window element having a coating comprising an oxidation
catalyst material for degradation of carbon-containing window
contaminations.
Inventors: |
Wahl; Claus; (Vaihingen/Enz,
DE) |
Correspondence
Address: |
Lipsitz & McAllister, LLC
755 MAIN STREET
MONROE
CT
06468
US
|
Assignee: |
Deutsches Zentrum fuer Luft-und
Raumfahrt e.V.
Koeln
DE
|
Family ID: |
36095856 |
Appl. No.: |
11/891299 |
Filed: |
August 9, 2007 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
PCT/EP06/01524 |
Feb 21, 2006 |
|
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11891299 |
Aug 9, 2007 |
|
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Current U.S.
Class: |
126/200 |
Current CPC
Class: |
F02P 15/006 20130101;
F23M 11/042 20130101; B08B 17/06 20130101; G01M 15/10 20130101;
C03C 17/06 20130101; C03C 17/008 20130101; C03C 17/23 20130101;
C03C 2217/228 20130101 |
Class at
Publication: |
126/200 |
International
Class: |
F24C 15/04 20060101
F24C015/04 |
Foreign Application Data
Date |
Code |
Application Number |
Feb 22, 2005 |
DE |
10 2005 009 285.3 |
Claims
1. Window device for a space laden with carbon-containing
particles, comprising: at least one optically transparent window
element; wherein said at least one window element has a coating
comprising an oxidation catalyst material for degradation of
carbon-containing window contaminations.
2. Window device in accordance with claim 1, wherein the oxidation
catalyst material is so selected that window contaminations are
degradable at least above a limit temperature.
3. Window device in accordance with claim 1, wherein the oxidation
catalyst material is so selected that window contaminations are
degradable at least above a temperature ranging from 300.degree. C.
to 450.degree. C.
4. Window device in accordance with claim 1, wherein the oxidation
catalyst material comprises a material from the 8.sup.th subgroup
of the Periodic Table.
5. Window device in accordance with claim 1, wherein the coating
comprises platinum.
6. Window device in accordance with claim 1, wherein the coating is
made of platinum or platinum-rhodium.
7. Window device in accordance with claim 1, wherein the oxidation
catalyst material comprises cerium oxide.
8. Window device in accordance with claim 1, wherein the coating is
vapor-deposited.
9. Window device in accordance with claim 1, wherein the coating is
subjected to a temperature treatment.
10. Window device in accordance with claim 1, wherein the coating
forms a surface of the at least one window element.
11. Window device in accordance with claim 1, wherein the coating
faces towards the inside area of the space laden with
carbon-containing particles.
12. Window device in accordance with claim 1, wherein the space
laden with carbon-containing particles is a combustion space.
13. Use of a coating with a material from the 8.sup.th subgroup of
the Periodic Table, in particular, a platinum coating or
platinum-containing coating, or with cerium oxide, on an optically
transparent window element for degradation of deposits of
carbon-containing material on windows.
14. Diagnosis system for combustion processes, comprising: at least
one optical sensor; and one or more window devices, said window
device comprising: at least one optically transparent window
element; wherein said at least one window element has a coating
comprising an oxidation catalyst material for degradation of
carbon-containing window contaminations.
15. Combustion chamber with a combustion space, which is provided
with at least one window device, said window device comprising: at
least one optically transparent window element; wherein said at
least one window element has a coating comprising an oxidation
catalyst material for degradation of carbon-containing window
contaminations.
Description
[0001] This application is a continuation of international
application number PCT/EP2006/001524 filed on Feb. 21, 2006.
[0002] The present disclosure relates to the subject matter
disclosed in international application number PCT/EP2006/001524 of
Feb. 21, 2006 and German application number 10 2005 009 285.3 of
Feb. 22, 2005 which are incorporated herein by reference in their
entirety and for all purposes.
BACKGROUND OF THE INVENTION
[0003] The invention relates to a window device for a space laden
with carbon-containing particles, in particular, for a combustion
space, comprising at least one optically transparent window
element.
[0004] It may prove necessary to observe combustion processes.
Window devices of the kind described at the outset are required for
this.
SUMMARY OF THE INVENTION
[0005] In accordance with the present invention, a window device is
provided, which can be employed in a simple way.
[0006] In accordance with an embodiment of the invention, the at
least one window element has a coating comprising an oxidation
catalyst material for degradation of carbon-containing window
contaminations.
[0007] Carbon-containing particles such as soot particles may
settle on the at least one window element of the window device, or
a layer of tar may also form on the at least one window element.
The transparency is thereby impaired, and, in the worst case,
observation of the space is no longer possible, i.e., the window
device no longer fulfills its function.
[0008] In accordance with the invention, a coating consisting of an
oxidation catalyst material for carbon is provided. Carbon can
thereby be catalytically oxidized to volatile constituents, in
particular, during the combustion of hydrocarbons, so that window
contaminations can be chemically degraded. A self-cleaning effect
for the corresponding window device is thereby provided, whereby
the observability is, in turn, ensured.
[0009] With the solution according to the invention, for example,
direct combustion processes can be observed by means of, for
example, a diagnosis system. By virtue of the self-cleaning effect,
a high degree of reliability is ensured in a quantitative
evaluation of the observation. The results of the analysis can then
also be used, for example, for controlling the combustion.
[0010] The window device according to the invention may be provided
as a separate device. It may also be, for example, part of an
optical diagnosis system, which, for example, comprises one or more
light guides. In this case, a light guide may constitute a window
element, and the coating is then disposed on the light guide.
[0011] In particular, the oxidation catalyst material is so
selected that window contaminations are degradable above a limit
temperature. At high temperatures from approximately 600.degree. C.
to 700.degree. C., carbon-containing window contaminations such as
layers of soot and layers of tar usually decompose by themselves.
Such deposits on windows can also be degraded at lower temperatures
by means of an oxidation catalyst material. In particular, deposits
of carbon-containing material on windows are degradable above a
temperature of from approximately 300.degree. C. to 450.degree.
C.
[0012] The oxidation catalyst material comprises, in particular, a
material from the 8.sup.th subgroup of the Periodic Table. The
coating may consist of such a material, or further materials may be
present in the coating. It is also possible for the coating to
comprise different oxidation catalyst materials.
[0013] In particular, the coating comprises platinum. Platinum acts
as an oxidation catalyst material, by means of which carbon can be
chemically transformed into volatile constituents. The coating may
be formed from platinum or comprise platinum.
[0014] For example, the coating is made from platinum or
platinum-rhodium.
[0015] It is also conceivable for, for example, yttrium or
palladium to be used as oxidation catalyst material.
[0016] It may, for example, also be provided that the oxidation
catalyst material comprises cerium oxide (CeO.sub.2). The coating
may be entirely or partially made from cerium oxide. It is expected
that the ignition temperature of soot will be reduced to
300.degree. C. to 350.degree. C. by cerium oxide as oxidation
catalyst material.
[0017] The coating can be produced in a simple way by
vapor-depositing. A thickness of the coating in the nanometer range
or submicrometer range can thereby be produced, which has a
sufficient oxidation catalyst property and, on the other hand, does
not impair the transparency of the window element to any
considerable degree.
[0018] It may be advantageous for the coating to be subjected to a
temperature treatment. This may possibly ensure better adhesion of
the corresponding coating; for example, the coating is
sintered.
[0019] In particular, the coating forms a surface of the at least
one window element, i.e., the coating on the window element faces
outwards (so that it can face into the combustion space).
[0020] It is then expedient for the coating to face towards the
inside area of the space laden with carbon-containing particles so
as to be able to degrade window contaminations coming from the
inside area.
[0021] In accordance with the invention, a coating with a material
from the 8.sup.th subgroup of the Periodic Table and, in
particular, a platinum coating or platinum-containing coating, or a
coating with cerium oxide, is used on an optically transparent
window element for degradation of deposits of carbon-containing
material on windows.
[0022] In accordance with the invention, a diagnosis system for
combustion processes is provided, which comprises at least one
optical sensor and one or more window devices according to the
invention. By means of the window device with the at least one
optically transparent window element, electromagnetic signals can
be coupled out and fed to an optical sensor for detection. The
coupling-out of signals is ensured by the solution according to the
invention.
[0023] The solution according to the invention may, for example, be
formed on a light guide, or a window device may be provided, which
is disposed in front of a light guide.
[0024] The solution according to the invention may be employed, in
particular, in conjunction with a diagnosis system as described in
DE 199 01 795 A1 and in U.S. Pat. No. 6,487,899.
[0025] Furthermore, in accordance with the invention, a combustion
chamber with a combustion space, having at least one window device
according to the invention, may be provided.
[0026] The combustion space of such a combustion chamber can be
observed by means of the at least one window device, with no
mechanical cleaning of the window device being required or the
cleaning intervals for the mechanical cleaning be considerably
prolongable.
[0027] The following description of preferred embodiments serves in
conjunction with the drawings to explain the invention in more
detail.
BRIEF DESCRIPTION OF THE DRAWINGS
[0028] FIG. 1 shows a schematic representation of an embodiment of
a combustion chamber which is provided with an embodiment of a
window device according to the invention;
[0029] FIG. 2 shows a schematic representation of an embodiment of
a diagnosis system which is disposed on a combustion chamber;
and
[0030] FIG. 3 shows an enlarged detail of the diagnosis system
according to FIG. 2 in a sectional view.
DETAILED DESCRIPTION OF THE INVENTION
[0031] A first embodiment of a window device according to the
invention, designated by 10 in FIG. 1, comprises a window element
12 which is optically transparent. The window element 12 is made,
for example, of quartz glass.
[0032] The window element 12 is, for example, in the form of a
window pane with flat surfaces 14, 16 spaced apart in parallel
relation to each other.
[0033] The window element 12 is held, for example, on a frame 18.
By means of this frame 18, the window device 10 is seated on a
combustion chamber 20. The frame 18 is fixed to a combustion
chamber wall 22 and held in this wall.
[0034] The combustion chamber 20 comprises a combustion space 24
which is laden with carbon-containing particles such as soot
particles. The carbon-containing particles result from the
combustion (indicated by reference numeral 26) of, for example,
hydrocarbons.
[0035] The carbon-containing particles may form a deposit on the
window element 12. Soot deposits, tar deposits, etc. may settle on
the window element 12. The optical transparency is thereby
impaired.
[0036] In accordance with the invention, a coating 28 facing
towards the combustion chamber 24 is provided on the window element
12. This coating 28 contains an oxidation catalyst material or is
formed by an oxidation catalyst material, by means of which carbon
is catalytically oxidizable to volatile components. Carbon deposits
on the window element 12 can thereby be disintegrated without any
mechanical cleaning of the window element 12 being required for
maintaining the optical transparency.
[0037] In particular, the coating 28 is formed by platinum or
platinum-rhodium, or the coating contains platinum or
platinum-rhodium as oxidation catalyst material.
[0038] It is, for example, also possible for the coating 28 to be
formed by cerium oxide (CeO.sub.2) or for the coating to contain
cerium oxide as oxidation catalyst material.
[0039] In particular, the oxidation catalyst material is
vapor-deposited onto the window element 12 to produce the coating
28. The coating 28 forms a surface of the window element 12, which
faces into the combustion space 24.
[0040] It may be provided that after its application, a coating is
subjected to a temperature treatment in order to ensure better
adhesion of the thus modified coating 28.
[0041] The thickness of the coating lies in the nanometer range
(with a thickness of a few nanometers) or in the submicrometer
range. The thickness of the coating should be comparable to the
wavelength of light and, in particular, it should be smaller.
[0042] By virtue of the solution according to the invention,
contaminations of the window element 12 can be degraded at least
above certain temperatures, so that no mechanical cleaning is
required. For example, it is thus possible for carbon-containing
contaminations on the window element 12 to be degraded above a
temperature of from approximately 300.degree. C. to 450.degree.
C.
[0043] A window device according to the invention with one or more
coated window elements can be disposed directly on a combustion
chamber 20. It is also possible for one or more corresponding
window devices to be disposed at a space such as, for example, a
flue space, which is in communication with a combustion chamber
20.
[0044] For example, it may also be provided that a diagnosis system
for combustion processes is provided with one or more window
devices according to the invention.
[0045] An example of a diagnosis system for combustion processes is
shown schematically in FIG. 2 and designated there in its entirety
by 30. It comprises one or more diagnosis elements 32 insertable in
a combustion space 34 in order to detect electromagnetic radiation
occurring in the combustion chamber. The combustion space 34 is
enclosed by a combustion chamber wall 36. The diagnosis system 30
comprises, in particular, one or more optical sensors.
[0046] The diagnosis element 32 is, for example, in the form of a
spark plug and has the usual spark plug elements and functions. For
example, a screw-in member 38 is provided, which is screwable into
a threaded bore 40 of the combustion chamber wall 36 and carries an
earth electrode 42 on its side facing the combustion space 34. Such
an earth electrode 42 is usually bent. The screw-in member 38
comprises an external thread 39.
[0047] Inserted in the screw-in member 38 is a ceramic member 44
which insulates a high-voltage electrode 46 extending through the
ceramic member 44 from the screw-in member 38. The high-voltage
electrode 46 projects with a front end 48 over the ceramic member
44 and is seated at a defined distance from the earth electrode 42
so as to be able to generate the ignition spark.
[0048] The ceramic member 44 is provided with a number of
through-holes 50 (FIG. 3), which extend from an end portion 52 of
the ceramic member 44 that is remote from the screw-in member 38 to
a front end portion 54 of the ceramic member 44 that tapers
conically in relation to the screw-in member 38 and projects into
the combustion space 34, and through this end portion 54 to an
opening 56 on the combustion chamber side, which preferably lies
close to the end 48 of the high-voltage electrode 46 at its
combustion chamber side and in the region of a conical surface 58
of the front end portion 54. The conical surface 58 preferably
extends conically in relation to an axis 60 which, at the same
time, is the center axis of the high-voltage electrode 46.
[0049] Inserted in each of the through-holes 50 is a light guide
62, which passes through the respective through-hole 50 and
terminates with a light guide end 64 at the combustion chamber
side. The light guide end 64 is preferably disposed so as to still
lie in the through-hole 50 extending through the ceramic member 44
at a distance from the opening 56 thereof at the combustion chamber
side, so that a portion 66 of the through-hole 50, which serves to
protect the light guide end at the combustion chamber side, remains
between the light guide end 64 at the combustion chamber side and
the opening 56 at the combustion chamber side.
[0050] At the same time, the portion 66 serves to define for the
electromagnetic radiation entering from the combustion space 34 an
aperture screen which sets an aperture A, with which it is possible
to detect electromagnetic radiation from a spatial area 49 of the
combustion space 34.
[0051] The light guide end 64 may be provided with a coating
corresponding to the coating 28. A window element is thereby formed
by means of the light guide itself, and the coating (indicated by
reference numeral 70 in FIG. 3) provides for a "self-cleaning" of
the light guide end 64 with respect to carbon deposits.
[0052] (Alternatively or additionally), it is also possible for a
window device 72 comprising a window element with a coating as
described hereinabove to be disposed at or in the proximity of the
opening 56. The portion 66 and hence the light guide end 64 is
mechanically closed off from the combustion space 34 by the window
device 72, so that no carbon-containing particles can reach the
light guide end 64.
[0053] The window device 72 with its oxidation catalyst material
coating has, as described hereinabove, a self-cleaning effect.
[0054] The light guide ends 64 are formed or possibly ground such
that a central direction of incidence E, forming a bisector of the
aperture A, of the electromagnetic radiation coming from the
combustion space 34 can run at an angle to the center axis 60 and
preferably also at an angle to a longitudinal direction 74 of the
through-hole 50 in a portion 76 of the through-hole 50 following on
from the portion 66, this portion 76 extending as far as an opening
of the through-hole 50, which is remote from the combustion space
34, and from which, for example, the light guide 62 is led out and
led to a diagnosis-compiling device 78.
[0055] The diagnosis-compiling device 78 comprises one or more
optical sensors, and, in particular, each light guide has its own
optical sensor.
[0056] A diagnosis system 30 as described hereinabove is disclosed
in DE 199 01 795 and in U.S. Pat. No. 6,487,899 and explained in
more detail therein. Reference is made explicitly to this
publication.
[0057] Combustion processes in the combustion space 34 can be
analyzed and a diagnosis made with such a diagnosis system. The
combustion processes can, for example, be controlled on the basis
of the diagnosis.
[0058] A deposit of carbon-containing material such as soot and/or
tar can be degraded by the window device according to the invention
(formed either by means of the light guide with the coating 70 or
by a separate window device 72), i.e., a self-cleaning function can
be provided. The optical transparency is thereby ensured, so that
light signals can reach the diagnosis-compiling device 78 with its
optical sensors.
* * * * *