U.S. patent application number 15/127088 was filed with the patent office on 2017-09-07 for device for the thermal post-combustion of exhaust air.
The applicant listed for this patent is Durr Systems AG. Invention is credited to Eberhard WAHL.
Application Number | 20170254531 15/127088 |
Document ID | / |
Family ID | 52781018 |
Filed Date | 2017-09-07 |
United States Patent
Application |
20170254531 |
Kind Code |
A1 |
WAHL; Eberhard |
September 7, 2017 |
DEVICE FOR THE THERMAL POST-COMBUSTION OF EXHAUST AIR
Abstract
A device for the post-combustion of exhaust air, comprises a
burner, which has a fuel nozzle, and a burner cone and which
protrudes in a raw-gas chamber, into an exhaust-air flow of exhaust
air to be treated at least by the burner cone of the burner. The
burner cone has a one- or a multi-part wall, which wall surrounds
the pre-mixing chamber and has one or more wall segments. The fuel
nozzle comprises an opening of at least one fuel outlet for
discharging fuel into the pre-mixing chamber. The wall bounding the
pre-mixing chamber outwardly on the lateral side has a structure
such that the pre-mixing chamber formed in the interior of the wall
opens in the downward direction in the manner of a funnel on at
least one cone longitudinal segment symmetrically to an axis of
symmetry defining the axial direction of the burner. The burner
cone comprises, in at least one longitudinal segment of the cone
longitudinal segment of the wall, which cone longitudinal segment
opens in the manner of a funnel, a plurality of tangential inlet
openings in order for exhaust air surrounding the burner cone to
enter the pre-mixing chamber tangentially.
Inventors: |
WAHL; Eberhard;
(Oppenweiler, DE) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
Durr Systems AG |
Bietigheim-Bissingen |
|
DE |
|
|
Family ID: |
52781018 |
Appl. No.: |
15/127088 |
Filed: |
March 16, 2015 |
PCT Filed: |
March 16, 2015 |
PCT NO: |
PCT/EP2015/055385 |
371 Date: |
March 13, 2017 |
Current U.S.
Class: |
1/1 |
Current CPC
Class: |
F23C 9/006 20130101;
F23C 2202/20 20130101; F23C 2900/07002 20130101; F23C 9/00
20130101 |
International
Class: |
F23C 9/00 20060101
F23C009/00 |
Foreign Application Data
Date |
Code |
Application Number |
Mar 20, 2014 |
DE |
10 2014 205 200.9 |
Claims
1-27. (canceled)
28. A device, comprising an industrial system (12) and a
post-combustion device (01), provided in an exhaust air stream (02)
of the industrial system (12) for the post-combustion of exhaust
air in the exhaust air stream (02), said device being separate from
the industrial system (12) and disposed downstream of said system,
wherein the post-combustion device (01) comprises a burner (04),
which has a fuel nozzle (07) and a burner cone (06), and which
protrudes, at least with its burner cone (06), in a raw gas chamber
(09) into exhaust air of the exhaust air stream (02) to be treated
that is coming from the system (12) upstream, wherein the burner
cone (06) has a single-part or multi-part wall (43) that surrounds
a premix chamber (42), and the fuel nozzle (07) comprises an
opening of at least one fuel outlet (44) for discharging fuel into
the premix chamber (42), and wherein the wall (43) that bounds the
premix chamber (42) outwardly on the lateral side has a structure
such that the premix chamber (42) formed inside the wall opens up
in the downstream direction in the manner of a funnel on at least
one longitudinal cone segment, symmetrically to an axis of symmetry
(S) that defines the axial direction of the burner (04),
characterized in that the burner cone (06) comprises, in at least
one longitudinal segment of the longitudinal cone segment of the
wall (43), which longitudinal cone segment opens up in the manner
of a funnel, a plurality of tangential inlet openings (54) in order
for exhaust air surrounding the burner cone (06) to enter the
premix chamber (42) tangentially, said inlet openings being formed
by a fan-like arrangement of a plurality of wall segments (43.1;
43.2; 43.3; 43.4).
29. The device according to claim 28, characterized in that the
tangential inlet openings (54) are spaced from one another
circumferentially and/or are each raised radially on the outside of
the wall (43) away from the preceding lateral circumferential
section, as viewed in the circumferential direction, and/or are
embodied as gap-like or slot-like openings that extend in the axial
direction, and/or extend that over at least the length of the
longitudinal cone segment that opens up in the manner of a
funnel.
30. The device according to claim 28, characterized in that the
wall (43) of the burner cone (06), at least in the longitudinal
cone segment that opens up in the manner of a funnel, is formed by
a plurality of n wall segments (43.1; 43.2; 43.3; 43.4) that are
arranged radially symmetrically in a fan-like manner around the
axial direction that forms the axis of symmetry (S) and/or are each
rotated around respective rotational axes that do not coincide with
one another or with the axis of symmetry (S), and/or the wall
segments (43.1; 43.2; 43.3; 43.4) are formed with a number of n
wall segments (43.1; 43.2; 43.3; 43.4) as N-th shells, in
particular as n partial conical shells.
31. The device according to claim 28, characterized in that the
wall (43) of the burner cone (06), at least in the longitudinal
cone section that opens up in the manner of a funnel, is formed by
a number n of more than two wall segments (43.1; 43.2; 43.3; 43.4)
that are arranged radially symmetrically in a fan-like manner
and/or are each rotated around the axial direction that forms the
axis of symmetry (S), and/or in at least one longitudinal segment
of the longitudinal cone segment of the wall (43) that opens up in
the manner of a funnel, comprises more than two tangential inlet
openings (54) for a tangential inlet of the exhaust air surrounding
the burner cone (06) into the premix chamber (42).
32. The device according to claim 28, characterized in that the
wall (43) of the burner cone (06), at least in the longitudinal
cone section that opens up in the manner of a funnel, is formed by
at least four wall segments (43.1; 43.2; 43.3; 43.4) that are
arranged radially symmetrically in a fan-like manner and/or are
rotated around the axial direction that forms the axis of symmetry
(S), and/or, in at least one longitudinal segment of the
longitudinal cone segment of the wall (43) that opens up in the
manner of a funnel, comprises at least four tangential inlet
openings (54) for a tangential inlet of the exhaust air surrounding
the burner cone (06) into the premix chamber (42).
33. The device according to claim 30, characterized in that the
angle segments that are covered with respect to the axis of
symmetry (S) in the circumferential direction by the respectively
adjacent wall segments (43.1; 43.2; 43.3; 43.4) continue at least
without gaps or overlap.
34. The device according to claim 30, characterized in that the
wall segments (43.1; 43.2; 43.3; 43.4) are in turn formed in the
circumferential direction by a number m of individual segments
(43.1x; 43.2x; 43.3x; 43.4x) that adjoin one another to form the
relevant wall section (43.1; 43.2; 43.3; 43.4).
35. The device according to claim 28, characterized in that the
tangential inlet openings (54) are configured such that only a flow
of air that is not a purely radial flow in relation to the axis of
symmetry (S) and instead comprises at least one tangential
component of motion can pass through these openings into the
interior of the cone.
36. The device according to claim 28, characterized in that the
structure of the wall (43) is embodied such that the premix chamber
(42) formed in its interior opens up in the manner of a funnel over
at least one longitudinal cone segment that is situated downstream
of the at least one fuel outlet (44) in the axial direction of the
burner (04) and extends in the axial direction of the burner,
symmetrically to the axis of symmetry (S) that defines the axial
direction of the burner (04), in a direction extending in the axial
direction of the burner from the fuel nozzle to the outlet side
premix chamber opening.
37. The device according to claim 28, characterized in that each of
the tangential inlet openings (54) is formed between two n wall
segments (43.1; 43.2; 43.3; 43.4) that adjoin one another in the
circumferential direction of the burner cone (06), in that said
wall segments are configured in the form of cone segments of a cone
that has a closed outer peripheral line, but are each arranged
rotated relative to the arrangement that forms the closed outer
peripheral line, around an axis that is spaced the same distance in
each case from the axis of symmetry (S), in the same direction of
rotation and/or the same angle.
38. The device according to claim 28, characterized in that the
burner (04) has, in an end-face bottom (49) of the burner cone
(04), one or more mouths of one or more passages (48) that lead
from the raw gas chamber (09) surrounding the burner (04) into the
premix chamber (42), through which passages exhaust air enters
and/or can enter the premix chamber from the raw gas chamber (09)
surrounding the burner (04), in an axial or predominantly axial
direction of flow, i.e. with an axial flow component that is
greater than the radial flow component.
39. The device according to claim 38, characterized in that in the
circumferential direction, a plurality of passages are provided in
an annular region of the bottom (49), which annular region extends
in a plane that runs perpendicular to the axis of symmetry (S)
outside of a circumferential line that projects into this plane and
that encompasses the mouth or mouths of the at least one fuel
outlet (44), said annular region also extending within the wall
(43) that extends at the axial height of the passages (48), and/or
said passages are provided in a base segment at the axial height or
axially upstream of the fuel nozzle end.
40. The device according to claim 38, characterized in that the
bottom (49) is formed by the side, facing the cone interior, of a
cone base (46) embodied as a shroud ring or spoke ring, which, as
viewed in the circumferential direction of the fuel nozzle (07),
has a plurality of passages (48) that extend predominantly in the
axial direction and/or that enable a predominantly axial flow.
41. The device according to claim 40, characterized in that the
cone base (46) that bounds the bottom (49) at its end face is
embodied in the manner of a flange (46), which can be detachably
connected to an attachment (47) arranged on the fuel nozzle (07) or
to an attachment situated upstream thereof, and/or which supports
the single-part or multi-part wall (43) of the burner cone (06)
spaced radially from the wall of the burner nozzle (07) and/or
which comprises predominantly axially extending passages (48) in
the region between the wall of the burner nozzle (07) and the wall
(43) of the burner cone (06).
42. The device according to claim 38, characterized in that the
bottom (49) the bottom (49) is formed by an intermediate space
between the upstream end of the wall (43) and the fuel nozzle (07)
at the axial level or axially upstream of the fuel nozzle end,
which intermediate space is open all the way around with the
exception of spoke-like supporting elements.
43. The device according to claim 40, characterized in that on a
circumferential line that lies radially further inward with respect
to the axis of symmetry (S) than the mouth of the one or more
bottom-side passages (48) on the interior side of the cone, but
lies radially further outward with respect to the axis of symmetry
than the opening of the at least one fuel outlet (44), a multi-part
guide element (51) that extends continuously or sectionally around
the entire circumference, or a multi-part guide element that is
interrupted sectionally is arranged radially between the at least
one fuel outlet (44) and the at least one passage (48).
44. The device according to claim 28, characterized in that the
fuel nozzle (07) and the upstream end of the burner cone (07), as
viewed in the axial direction, are arranged overlapping or at least
continuing without interruption, and/or the wall (43) of the burner
cone (06), in particular a base segment of the burner cone (06),
surrounds the fuel nozzle (07) at least at the level of the at
least one fuel outlet.
45. The device according to claim 28, characterized in that all or
a plurality of the wall segments (43.1; 43.2; 43.3; 43.4) of a wall
(43) that is embodied as a multi-part wall are configured, at least
in the longitudinal cone section that opens up, in the form of
shroud segments (43.1; 43.2; 43.3; 43.4) of a radially
symmetrically configured frustoconical or I-sided frustopyramidal
shroud that has a closed profile, and are arranged rotated in the
same direction of rotation and by the same angle of rotation, about
respective axes that extend in the longitudinal direction on a
common conical or cylindrical lateral surface that encompasses the
axis of symmetry (S) concentrically.
46. The device according to claim 28, characterized in that the
burner cone (04), in its burner cone segment that opens up or in at
least a portion of this burner cone segment, has an effective inner
taper having a slant angle (.phi.; .phi.1) of the conical shroud of
5.degree. to 15.degree. in relation to the axis of symmetry
(S).
47. The device according to claim 28, any one of the preceding
claims, characterized that the inner wall (43) of the burner cone
(06) that bounds the premix chamber (42) outwardly on the lateral
side is configured in terms of its shape and its structure, at
least in the longitudinal cone section that opens up in the manner
of a funnel, to accommodate a maximum virtual truncated cone with
the largest possible cross-sectional profile, which is in contact
with the wall (43) at at least three points, spaced from one
another circumferentially, in each of at least two cross-sectional
planes that are spaced from one another axially, wherein the wall
(43) of the burner cone (06) is configured such that, in a plane
that comprises the axis of symmetry, this maximum virtual truncated
cone forms a cone angle of 18.degree. to 30.degree., in particular
20.degree. to 26.degree., preferably 23.degree..+-.1.degree..
48. The device according to claim 28, characterized in that the
wall segments (43.1; 43.2; 43.3; 43.4) of the burner cone (06) that
bound the premix chamber (42) outwardly on the lateral side, in the
longitudinal cone section that opens up in the manner of a funnel,
are configured in terms of their shaping and their structure as
having a taper that varies in the circumferential direction in
relation to the axis of symmetry (S), a lateral surface line that
extends in this longitudinal cone segment that opens up in the
manner of a funnel, in the longitudinal direction of the burner
cone on the inside of the wall segment (43.1; 43.2; 43.3; 43.4) in
the longitudinal direction of the burner (04), and that is slanted
the most in relation to the axial direction forms a slant in
relation to the axial direction having an slant angle (.phi.2) of
no more than 16.degree., advantageously no more than 15.degree., in
particular no more than 13.degree., and/or a lateral surface line
that extends in this longitudinal cone segment that opens up
therein in the manner of a funnel, in the longitudinal direction of
the burner cone on the inside of the wall segment (43.1; 43.2;
43.3; 43.4) in the longitudinal direction of the burner (04), and
that is slanted the least in relation to the axial direction forms
a slant in relation to the axial direction having a slant angle of
at least 8.degree., advantageously at least 9.degree., in
particular at least 10.degree..
49. The device according to claim 28, characterized in that the
burner cone (06) comprises, in the region of its downstream end, a
cover element (53) that is connected to the wall (43) and that
comprises an outlet opening (13) that leads out of the cone
interior at the end face of the burner cone (06) in the
circumferential direction, and extends with its inner
circumferential line that delimits the outlet opening (13) in a
plane that is perpendicular to the axial direction, said cover
element extending, in an inner and/or outer edge region, in
particular in the manner of a collar, radially beyond the profile
that is defined at the end face by the lateral profile of the wall
(43), into the space surrounding the burner cone (06) and/or into
the space that is surrounded by the cover element (53).
50. The device according to claim 28, characterized in that the
burner cone (06) is configured, in the region of its downstream
end, as having a plurality of flow restrictors (59; 63; 64; 66)
that extend out of the profile defined at the end face by the
lateral profile of the wall (43), and into the space surrounding
the burner cone (06) at its downstream end, and that are spaced
from one another in the circumferential direction of the burner
cone (06).
51. The device according to claim 50, characterized in that a
plurality or all of the flow restrictors (59; 63; 64; 66) are
arranged on a cover element (53) according to claim 20, and/or are
formed as guide vanes (59; 63; 64) made of flat sheet metal
material, which are embodied as planar or as having at least one
planar portion, wherein said flow restrictors are arranged with
the, or with at least one of their planar portions slanted in
relation to the plane of the outlet opening (16), which is
perpendicular to the axial direction.
52. The device according to claim 28, characterized in that the
burner (04) protrudes with at least its burner cone (06) into an
exhaust air stream (02) of exhaust air to be treated, which comes
from an industrial system (12) and contains a hydrocarbon load.
53. The device according to claim 28, characterized in that a raw
gas inlet (19) is provided, via which the fluid stream or exhaust
air stream (02) to be purified, coming from the system (03), can be
fed as a raw gas stream (02) to the device.
54. The device according to claim 28, characterized in that
upstream of the raw gas chamber (09) in the raw gas path, a heat
exchanger (24) is provided, by means of which an exchange of heat
is or can be carried out between already treated, hot, purified gas
exiting a combustion chamber (11) and a raw gas formed by exhaust
air from the system (12) upstream that has yet to be treated.
55. The device according to claim 28, characterized in that a
combustion chamber (11) is connected downstream of the raw gas
chamber (09) that surrounds the burner cone (06).
56. The device according to claim 28, characterized in that an
inlet opening of the combustion chamber (11) and the burner cone
(06), at the level of outlet opening (13), are dimensioned and
arranged relative to one another such that between the edge of the
burner cone (06) that defines its external periphery on the outlet
side and the edge of an inlet-side combustion chamber wall (17)
that defines the inlet opening an inlet gap (18) is formed, through
which raw gas is able to flow out of the raw gas chamber (09) and
into the combustion chamber (11) on a direct path, i.e. without
first passing into a premix chamber of the burner cone (06) that is
formed in the interior of the burner cone (06).
57. The device according to claim 28, characterized in that for the
inlet of exhaust air into the raw gas chamber (02), a route segment
through a flow cross-section (21) is provided, which is bounded on
at least one side by the exterior of a combustion chamber wall
(22).
Description
CROSS REFERENCE TO RELATED APPLICATIONS
[0001] This application is the U.S. national phase, under 35 U.S.C.
.sctn.371, of PCT/EP2015/055385, filed Mar. 16, 2015; published as
WO 2015/140085A1 on Sep. 24, 2015 and claiming priority to De 10
2014 205 200.9, filed Mar. 20, 2014, the disclosures of which are
expressly incorporated herein by reference.
FIELD OF THE INVENTION
[0002] The present invention relates to a device comprising an
industrial system and a post-combustion device. The device is
provided in an exhaust air stream of the industrial system for the
post-combustion of exhaust air in the exhaust air stream. The
device is separate from the industrial system and is disposed
downstream of that system. The post-combustion device comprises a
burner which is a fuel nozzle and a burner cone, and which
protrudes, at least with its burner cone, in a raw gas chamber into
exhaust air of the exhaust air stream to be treated that is coming
from the system upstream. The burner cone has a single-part or a
multi-part wall that surrounds a premix chamber. The fuel nozzle
comprises an opening of at least one fuel outlet for discharging
fuel into the premix chamber. A wall that bounds the premix chamber
outwardly, on the lateral side, has a structure such that the
premix chamber, which is formed inside the wall, opens up, in the
downstream direction, in the manner of a funnel on at least one
longitudinal cone segment, symmetrically to an axis of symmetry
that defines the axial direction of the burner.
BACKGROUND OF THE INVENTION
[0003] A brochure entitled "CleanAir Exhaust Air Purification
Systems", published by KBA MetalPrint and dated March 2008, in the
section relating to the "thermal exhaust air purification TNV"
process, describes a device for the thermal post-combustion of
exhaust air having a burner, the burner cone of which opens up in
the manner of a funnel in the axial direction of the burner toward
the downstream cone opening. The burner is arranged with at least
the burner cone in a chamber situated upstream of a combustion
chamber, and is surrounded by exhaust air to be treated. A tube
bundle heat exchanger that exchanges thermal energy with the
purified gas stream is provided in the exhaust gas stream flowing
upstream of the burner.
[0004] DE 37 38 141 A1 discloses a burner, the burner cone of which
encompasses a fuel nozzle tube. The wall segment of the cone, which
opens up in the shape of a frustoconical shroud, is equipped with
through-openings, through which exhaust gas can flow from a channel
that surrounds the cone and conducts the exhaust gas into the
interior of the cone. Parallel to this, exhaust gas flows through
an annular gap that is formed between the combustion chamber
faceplate and the cone into the combustion chamber. To prevent any
damage that may result from overheating, the burner cone is made of
what is known as engineering ceramics, in particular silicon
infiltrated silicon carbide.
[0005] DE 196 54 009 A1 discloses a cone burner which has a burner
cone comprising two partial conical shell-shaped bodies that are
offset from one another radially at their end sections, as viewed
in the circumferential direction, and thereby form tangential inlet
openings for combustion air. In the region of the cylindrical
beginning part of the cone, liquid fuel is preferably atomized via
a nozzle into the cone interior. In the region of the tangential
inlet openings, gaseous fuel is also preferably injected via
nozzles through radially inwardly directed openings in the wall of
the partial body, into the combustion air that is flowing in
tangentially. The evaporation inside the premix chamber of the
liquid fuel that has been injected through the nozzle can be
supported by preheating the infed combustion air or by enriching
said combustion air with recycled exhaust gas.
[0006] DE 41 13 681 A1 and DE 195 45 310 A1 disclose burner
embodiments similar to that of DE 196 54 009 A1, however in DE 41
13 681 A1 the radial injection into the tangential inlet openings
is carried out via radially directed openings in feed conduits that
extend parallel to the inlet openings. In this case as well, a
recirculation of a certain quantity of the exhaust gas into the
supplied fresh air to produce the combustion air may prove
advantageous when used with gas turbine groups or atmospheric
combustion installations. In DE 195 45 310 A1, the burner cone is
formed by a plurality of partial conical shell-shaped bodies, in
the description of one embodiment, four such bodies. The conical
axes of the conical partial shells lie along a common cone axis,
resulting in a straight conical lateral surface line that is
interrupted by inlet channels.
[0007] DE 195 45 309 A1 discloses a premix burner for use with a
gas turbine group, for example, and having two partial conical
bodies, between which slot-like tangential inlet openings are
formed for the inlet of compressed combustion air that is produced
in a compressor. Gaseous fuel is injected in the region of the
tangential inlet slots. At partial load, if operation is no longer
guaranteed solely by the injection in the region of the slots, fuel
is additionally injected via a nozzle through a feed lance in the
region of the backflow zone, thereby avoiding any pulsation between
full-load and partial-load operation. In a hollow space between the
lance tube that delimits the feed lance and the fuel tube arranged
coaxially therein, combustion air flows to the lance tip, which
leads to the area of the backflow zone.
[0008] CH 684 962 A5 discloses a burner for operating an internal
combustion engine, a combustion chamber of a gas turbine group, or
a combustion installation, having a burner cone which is likewise
formed by partial conical bodies, in which fuel is injected in the
region of the tangential inlet slots. If necessary, in addition to
being introduced tangentially, axial combustion air may be
introduced downstream of the ignition electrodes into the hollow
conical space.
[0009] DE 102 05 428 A1 relates to a burner for a heat generating
system. Flow restrictors are provided in the outlet opening of the
burner.
[0010] WO 2006/048405 A1 also relates to a burner for a heat
generating system. On the outlet side of the burner cone, internal
attachments that form transition channels are provided in the flow
path of the exiting combustion gas stream.
[0011] U.S. Pat. No. 6,599,121 B2 relates to a burner for a turbo
power machine having a plurality of conical partial shells, in
which, in the slots that are formed between said partial shells,
combustion air is provided with fuel and is introduced tangentially
into the cone interior. To stabilize the burner in terms of fluid
mechanics, in at least one circumferential section a
cross-sectional tapering is provided at some points along the axial
profile of the conical flow by appropriate shaping or internal
attachments that deform the flow profile. The circumferential
section that has a tapering cross-section extends at an angle of
2.degree. to 45.degree., especially 5.degree. to 15.degree., in
relation to the burner axis in the last one-third of the burner
cone downstream.
[0012] EP 0629817 A2 discloses a combustion system that consists
substantially of a combustion chamber with a premix burner. In said
system, flue gas that is produced during the combustion of fuel is
passively recirculated. The burner cone comprises two tangential
inlets, formed by the offset of two conical partial bodies, for the
inlet of combustion air. Fresh air is fed to the burner axially in
the base region and radially in the cone region, as a tangential
flow that draws flue gas along with it into the interior of the
burner by virtue of the suctioning effect of jet injectors. Fuel
nozzles are provided in the region of the tangential inlets.
[0013] DE 100 22 969 A1 relates to a burner for operating a unit
for generating a hot gas, comprising a burner cone formed by two
conical partial bodies in a fan-like arrangement. To reduce the
amplitudes of thermoacoustic oscillations, a plurality of flow
restrictors project into the flow. The flow restrictors are
preferably provided at the burner outlet and are particularly
advantageously also provided along the tangential air openings.
Openings for the infeed of fuel may also be provided in the region
of the tangential air openings.
[0014] EP 0 780 630 A2 relates to a burner for a heat generator.
The burner comprises a conical swirl generator and a fuel nozzle.
The burner cone comprises two tangential inlets, formed by the
offset of two conical partial bodies, for the inlet of combustion
air. The combustion air may be enriched with recirculated exhaust
gas for preheating. In the region of the fuel nozzle tip, openings
are provided, arranged radially or quasi-radially, through which a
scavenging air flows into the cross-section, which is determined by
the size of the fuel nozzle.
[0015] JP 2004 053 048 A discloses a premix burner in which, in a
front wall that bounds the cone on the base side, axial bores
appear to be provided, which lead on the other side into a pilot
mixed gas line. The cone comprises apertures through which a main
fuel gas mixture flows from the outside into the cone interior.
[0016] US 2007/0254254 A1 relates to a conical cyclonic oxidizing
burner, in which hydrocarbon-containing gas obtained from a
pyrolysis unit is fed to the side of the burner that has a smaller
cross-section. Fuel, e.g. in the form of propane, can be fed via
hoses to the interior of the conical burner basket in the region of
the cone wall. Also provided in the wall of the conical burner
basket are rings of openings, on the inner sides of which dampers
are provided for generating a cyclonic flow. These measures,
optionally along with a fan source that can be used to generate a
circular flow in the combustion chamber surrounding the burner
basket, are designed to generate a cyclonic flame on the inner wall
of the burner basket.
[0017] DE 198 48 661 A1 relates to a thermal post-combustion system
in which a burner is arranged with its cone in the exhaust gas
stream. Openings are provided in the conical shroud, through which
the exhaust air flows into the cone interior. To form a swirling
flow, the openings located farthest downstream are equipped with
elements that project inward for directing the flow of exhaust
air.
[0018] GB 1 276 199 A also relates to a thermal post-combustion
system for polluted exhaust air, which has a burner cone arranged
in the exhaust air stream and comprising radial air openings.
[0019] EP 0 436 113 A1 discloses a burner for a combustion system,
to which flue gas that is recirculated from the burner is fed, in
addition to fresh air.
SUMMARY OF THE INVENTION
[0020] The object of the present invention is to provide a device
that comprises an industrial system and a post-combustion
device.
[0021] The object is achieved according to the invention by the
provision of the burner cone having, in at least one longitudinal
segment of the longitudinal cone segment of the wall, which
longitudinal cone segment opens up in the manner of a funnel, a
plurality of tangential inlet openings in order for exhaust air
surrounding the burner cone to enter the premix chamber
tangentially, the inlet opening being formed by a fan-like
arrangement of a plurality of wall segments.
[0022] The advantages that can be achieved with the invention
consist in particular in that it enables a particularly effective
and energy-efficient post-combustion of exhaust air, which
nevertheless meets high standards in terms of residual
pollutants.
[0023] High efficiency is promoted, for example, by preheating the
exhaust air that will be post-combusted to temperatures, e.g. of
>500.degree. C. and/or by directing the flow of the exhaust air
and/or fuel in a way that is advantageous to a premixing of the
exhaust air to be purified with the fuel gases.
[0024] For the embodiment of a post-combustion device, it is
therefore particularly advantageous, e.g. for the exhaust air that
will be purified to be preheated in conjunction, preferably in
conjunction with a burner designed specifically for that
purpose.
[0025] Overheating and damage to the burner wall are prevented, for
example, by a specific direction of the flow of air in the burner
or burner cone that has no negative impact on mixing and hence on
the effectiveness of post-combustion. By means of a tangential air
inlet and/or an air inlet entering predominantly axially close to
the conical shroud on the bottom side, and/or a specific actual or
effective taper, for example in an angle range for the opening
angle ranging, e.g. from 10.degree. to 30.degree., in particular
from 14.degree. to 24.degree., or in an angle range for the slope
of the cone wall of the effective inner or actual cone ranging,
e.g. from 5.degree. to 15.degree., in particular from 7.degree. to
12.degree., a cushion of inlet air is generated or maintained on
the inner wall of the burner cone, so that the flame is generated
in an "air basket" that is formed in this manner.
[0026] An embodiment of the burner cone having tangential air inlet
openings can be particularly advantageous for the formation of a
swirling flow--which, e.g. stabilizes the flame despite any
additional radial inlet of air that may occur. These air inlet
openings can preferably be formed by configuring the burner cone
shroud or at least a portion thereof as a radially symmetrical, in
particular a fan-like and/or rotated arrangement of a plurality of
wall segments, e.g. more than two, preferably four, of a wall
embodied as comprising a single part, or preferably multiple
parts.
[0027] The formation of the air basket that protects the wall
against excessively high temperatures can advantageously result
from, or can at least be promoted by radial air inlet openings in
the wall and/or in particular by an air inlet proceeding from the
bottom and/or by the conical shape.
[0028] In an advantageous embodiment in which the flow of inlet air
proceeds from the bottom and is directed along the wall, i.e. an
annular lateral flow that forms the air basket, an advantageous
refinement involves this inlet air flowing in between the
bottom-side end face of the conical shroud and an additional
annular guide element, e.g. guide plate, which encompasses the
end-face burner nozzle profile.
[0029] For the purpose of forming the air basket, as an alternative
to the above, or preferably in addition to the axial flow of inlet
air and/or in addition to the swirling flow and/or in addition to
the preferred conical geometry, i.e. the shell-like structure
and/or the taper, radial air inlet openings, for example as
injector openings, may be provided in the conical shroud. The
degree of openness of the injector openings, or of some of the
injector openings, may be variable to allow the air flow and the
flow of air along the shell to be adjusted.
[0030] Mixing and hence the effectiveness of post-combustion can be
improved, solely or even in conjunction with the axial inlet air
stream and/or the swirling flow and/or the shell-like cone
structure and/or the taper and/or the radial air inlet openings in
the region of the downstream end of the cone, by means of flow
restrictors that project into the space surrounding the burner cone
on its exterior, close to or in the plane of the outlet opening of
the burner cone. This improvement is achieved particularly in
conjunction with the annular flow along the shroud, which must be
broken up at the end of the cone and swirled with the remaining
flow of inlet air.
[0031] Particularly in addition to the axial inlet air stream
and/or the swirling flow and/or the shell-like cone structure
and/or the taper and/or the radial air inlet openings and/or the
flow restrictors, the burner cone may also comprise a cover plate
on the downstream side, by means of which a necessary pressure
difference is produced inside the cone and/or tangential inlet
openings are closed.
[0032] The burner and the post-combustion device are embodied to
function together, for example, such that when the burner is
operated, the exhaust air is heated to a temperature level of
>600.degree. C., in particular greater than 650.degree. C.,
preferably >700.degree. C., e.g. about 750.degree. C., at which
the pollutants, e.g. hydrocarbons, react with the oxygen from the
exhaust air to produce CO/CO.sub.2 and water.
[0033] Exhaust air is understood here, for example, as exhaust air
streams or exhaust gas streams that contain, e.g. a significant
hydrocarbon load and/or a hydrocarbon load that is above the limits
allowable in Germany, for example. For example, the exhaust gas
stream or exhaust air stream to be treated and/or surrounding the
burner cone contains at least 5 g/m.sup.3 hydrocarbon
compounds.
[0034] In an advantageous refinement of the post-combustion device,
an exchange of heat is provided in the purified gas stream, by
means of which thermal energy can be released in a fluid stream for
a process or for heating the system that emits the exhaust air to
be purified.
BRIEF DESCRIPTION OF THE DRAWINGS
[0035] Embodiment examples of the invention are illustrated in the
set of drawings and will be specified in greater detail in the
following.
[0036] The drawings show:
[0037] FIG. 1 a schematic diagram of a post-combustion device
situated downstream of an industrial system;
[0038] FIG. 2 an enlarged representation of the post-combustion
device of FIG. 1;
[0039] FIG. 3 a schematic diagram showing a front portion of the
post-combustion device with a burner;
[0040] FIG. 4 an oblique, perspective view from the front of an
embodiment of the burner;
[0041] FIG. 5 a perspective view from the rear of an embodiment of
the burner;
[0042] FIG. 6 a side view of an embodiment of the burner;
[0043] FIG. 7 a schematic diagram illustrating a) a first and b) a
second cross-section through the wall of the burner;
[0044] FIG. 8 a schematic longitudinal sectional view of the burner
in the region of an outlet opening of the fuel nozzle;
[0045] FIG. 9 a slightly perspective view from the front of an
embodiment of the burner.
DESCRIPTION OF THE PREFERRED EMBODIMENT
[0046] A device 01 for the thermal aftertreatment, in particular
for the post-combustion of a gaseous fluid stream 02, for example
contaminated with pollutants, e.g. a post-combustion device 01,
comprises a burner 04 that can be or is operated using liquid or
preferably gaseous fuel 03, in particular a cone burner 04
comprising a fuel infeed 07, e.g. fuel nozzle 07, and what is known
as a burner cone 06, with at least the burner cone 06 of said cone
burner projecting into and/or being arranged in the flow path of
the fluid stream 02, in particular the exhaust air stream 02, to be
treated. The preferably gaseous fuel 03, e.g. natural gas, propane
or LPG, can be fed into the space surrounded by the burner cone 06
via fuel nozzle 07 (see, e.g. FIG. 1, FIG. 2 and FIG. 3).
[0047] For the sake of simplicity--unless otherwise specifically
distinguished in the relevant passage--the term "exhaust air" used
for the gaseous fluid to be purified is understood both as a fluid
actually in the form of a process exhaust air or "cold exhaust gas"
and as a "hot" exhaust gas, in particular as a fluid in the form of
combustion exhaust gas to be treated thermally by post-combustion,
or as a fluid stream 02 in the form of an exhaust air or exhaust
gas stream 02. The "exhaust air" that has not yet been thermally
aftertreated by post-combustion, also referred to as raw gas,
comes, for example, from a system 12, in particular an industrial
system, situated on the upstream side (or even upstream) of the
device 01 with respect to the exhaust air to be treated. For
example, this air that is actually in the form of exhaust air, e.g.
in the form of indoor air or process exhaust air that is
contaminated with pollutants, comes from a room in an industrial
plant or from a process of a system 12 embodied as a production
and/or processing system 12, or this air in the form of combustion
exhaust gas comes from a combustion chamber of a system 12 embodied
as a combustion system 12.
[0048] During thermal aftertreatment, the exhaust air that is
loaded with pollutants is heated by an open flame, and oxidizable
pollutants, such as hydrocarbons, are oxidized at high
temperatures, e.g. temperatures >600.degree. C., in particular
greater than 650.degree. C., preferably >700.degree. C. For
example, hydrocarbons are oxidized to carbon dioxide and water. The
oxygen required for this process is entrained and/or supplied, for
example, as a constituent of the raw gas to be purified. Unlike
burner systems that are used for generating power, in this case
burner 04 is not specifically charged, e.g. with--in particular
compressed--ambient air (i.e., a gas mixture typical of
low-pollution purified air), and is instead located in an
atmosphere or environment formed by exhaust air and having a
hydrocarbon concentration, e.g. of at least or greater than 0.5
g/m.sup.3 (25.degree. C., 1,013 mbar), in particular of at least
1.0 g/m.sup.3. In other words, in addition to the fuel on the raw
gas side 03, only an exhaust air which is contaminated with
pollutants but which carries an oxygen fraction of, e.g. at least
5%, preferably at least 10%, and has a hydrocarbon load of at least
0.5 g/m.sup.3 is fed to burner 04.
[0049] Downstream of the post-combustion process, a purified gas
stream 08 comprising the thermally aftertreated raw gas stream 02
exits the post-combustion device 01.
[0050] In a first embodiment of post-combustion device 01 which is
least complex and not explicitly shown here, burner 04 or the
burner cone 06 thereof can protrude directly into a pipe segment of
a pipeline that discharges the exhaust air stream 02 of system 06,
or can be provided in such a pipe segment. This pipe segment can be
widened in the form of a chamber in terms of its cross-section in
relation to an intake segment of the pipeline on the raw gas side
and an outlet segment of the pipeline on the purified gas side.
[0051] In an embodiment that is preferable with respect to handling
and/or modularity and/or efficiency, burner 04 is part of a device
01 configured as an independent post-combustion unit 01, and
projects with at least burner cone 06 into a raw gas chamber 09
that conducts the exhaust air to be treated in the interior of unit
01. Raw gas chamber 09 that surrounds burner cone 06 is connected
downstream to a combustion chamber 11, with a downstream outlet
opening 13 of burner cone 06 leading to the inlet opening of said
combustion chamber, and with the combustion chamber having one or
more parallel outlet openings 14; 16 for the outlet of the
post-combusted purified gas from combustion chamber 11.
[0052] The inlet opening of combustion chamber 11 and burner cone
06, at the level of outlet opening 13, are dimensioned and arranged
relative to one another, e.g. such that between the edge of burner
cone 06 that defines its external periphery on the outlet side and
the edge of a combustion chamber wall 17 on the inlet side, in
particular the end-face side, that defines the inlet opening, an
inlet gap 18 is formed, through which raw gas is able to flow out
of raw gas chamber 09 and into combustion chamber 11 on a direct
path, i.e. without first passing into a premix chamber of the
burner cone 06, formed in the interior of burner cone 06. This
inlet gap 18 can be embodied as a freely open inlet gap 18 that
extends continuously around the periphery--if appropriate with the
exception of supporting and/or retaining elements arranged between
burner cone 06 and combustion chamber 11--or as a freely open inlet
gap that extends in total, e.g. over a total angle range of at
least 270.degree., preferably at least 300.degree. of the
circumference. The plane of the inlet opening into combustion
chamber 11 and the plane of the outlet opening 13 of burner cone 06
need not, but may coincide. However, they may also be spaced from
one another, parallel to one another and in the axial direction of
burner 04, so that the cross-sectional area of the gap encircling
the burner cone edge, which is planar when these two planes
coincide, forms a frustoconical shroud-like area if the two planes
are offset axially.
[0053] The fluid stream or exhaust air stream 02 to be purified can
be fed as a raw gas stream 02 to raw gas chamber 09 provided inside
post-combustion unit 01, in particular to a raw gas inlet 19 of
post-combustion unit 01, on the upstream side or the raw gas side,
from system 03 via an appropriate pipeline.
[0054] In a simple variant, raw gas inlet 16 can lead directly into
the raw gas chamber 09 surrounding burner cone 06.
[0055] In a variant that is advantageous in terms of power,
however, the flow is fed into raw gas chamber 09 via a flow path
along a route segment through a flow cross-section 21 that is
bounded on at least one side by the exterior of a combustion
chamber wall 22, in particular a longitudinal combustion chamber
wall 22. For the preferred case of a cylindrical combustion chamber
11 and a cylindrical shell 23, e.g. outer shell 23 of
post-combustion unit 01, which surrounds the combustion chamber 11
concentrically, at least over the length of combustion chamber 11,
flow cross-section 21 may be formed as an annular gap 21 over at
least one path segment. This annular gap can be embodied as a
freely open flow cross-section that extends over the entire
circumference of the circular ring--with the exception of any
supporting and/or retaining elements that may be provided between
combustion chamber 11 and shell 23--or, e.g. as a freely open
cross-section that occupies a total of at least 80%, preferably at
least 90% of the uninterrupted area of the circular ring. As
exhaust air of the exhaust air stream 02 that will be
post-combusted further downstream flows along combustion chamber
outer wall 22, it can absorb energy in the form of heat by way of a
heat exchange with combustion chamber outer wall 22.
[0056] In place of, or preferably in addition to a heat exchange
with combustion chamber outer wall 22, a heat exchanger 24 for
recuperative heat exchange, e.g. embodied as a tube bundle heat
exchanger 24 having a plurality of pipes 26 configured for parallel
flow, can be provided in the raw gas path, upstream of raw gas
chamber 09, preferably upstream of the e.g. annular flow
cross-section 21 that extends along combustion chamber outer wall
22, which heat exchanger is or can be used for an exchange of heat
between the already post-combusted hot, purified gas of the
purified gas stream 08 and the raw gas of the raw gas stream 02
that has yet to be purified. In principle, heat exchanger 24 can be
embodied as a separate unit disposed upstream of device 01, or
preferably as structurally integrated into post-combustion unit 01
and disposed downstream of raw gas inlet 19 in the flow path.
[0057] In this case, in principle, the raw gas either can be
conducted within the tubes 22 of heat exchanger 24 or, preferably,
can bypass the tubes 26 of heat exchanger 21 on their exterior.
Conversely, the purified gas can bypass the tubes 26 of heat
exchanger 21 on their exterior, or can preferably be conducted
within the parallel tubes 22 of heat exchanger 24 to a common
collection and discharge chamber 27, before the purified gas stream
08 exits device 01 through a purified gas outlet 28.
[0058] In the advantageous embodiment illustrated, the unpurified
exhaust air is conducted through the tube bundle of heat exchanger
24 in the cross-flow/counter-flow. The exhaust air is preheated and
flows within the outer annular gap 21 around combustion chamber 11
to the opposite end of combustion chamber 11, where it is deflected
toward burner 04. In an advantageous embodiment described in
greater detail below, one portion of the exhaust air flows from the
side and/or from the upstream end face through burner 04 itself,
and thereby also serves as a source of oxygen for combustion in the
burner 04, while another portion flows past burner 04 passing
through inlet gap 18, which is annular, for example, into
combustion chamber 11. The two parts are then mixed with the hot,
combusted exhaust air/gas mixture from burner cone 06 to a target
temperature of, e.g. >700.degree. C., e.g. 720.degree. C. to
750.degree. C. The pollutant gases (primarily hydrocarbons)
contained in the uncombusted exhaust air then burn in the
combustion chamber to CO.sub.2 and water, as soon as they reach the
desired reaction temperature. Advantageously, the turbulence in
combustion chamber 11 and the dimensions of the geometric
configuration thereof are such that the residence time in
combustion chamber 11, e.g. at least 0.5 seconds, is sufficient to
cause the fractions of residual CO, NO.sub.x and uncombusted
hydrocarbon concentrations to drop below legally permitted levels.
The combusted, purified exhaust air then flows out through the
tubes of heat exchanger 24 and gives up a large portion of its heat
to the unpurified exhaust air flowing behind it.
[0059] In addition to tubes 26 of heat exchanger 24, a bypass route
29--e.g. extending centrally--may be provided, the flow-through
rate of which can be adjusted remotely, for example by means of a
control means 34, for example, an actuating drive 34, via an
adjusting element 31, e.g. an adjustable damper 31. This allows the
heating of the raw gas, for example, to be varied within
limits.
[0060] For conveying the raw gas that will be post-combusted
through post-combustion device 01, a gas conveying means 32, e.g. a
conveying means embodied as a ventilator, a compressor or a pump,
can be provided in post-combustion device 01 or in the tubing that
conducts the raw gas stream 02 leading to post-combustion device
01.
[0061] In an embodiment of post-combustion device 01 that is
provided in place of or preferably in addition to heat exchanger
24, or in an exhaust air treatment system that comprises device 01,
downstream of the post-combustion device 01, which is preferably
embodied with or optionally without heat exchanger 24, a heat
recovery device 33 can be provided in the flow path of purified gas
stream 08. In principle, heat recovery may be based on any
technology, but is preferably embodied as recuperative, with a
recovery of the heat via a heat exchanger 36 between the still hot,
purified gas stream 08 and a fluid of a heat exchanger fluid stream
37 on the usable heat side, e.g. a heating fluid cycle 37. Although
the heat recovery device 33 may, in principle, likewise be
structurally integrated into the post-combustion device 01
configured as unit 01, if provided it is preferably embodied as an
independent unit 33 situated downstream of post-combustion device
01 in a system for exhaust air treatment. For example, the output
of heat can be variable, for example, over the flow route by remote
actuation via a control means 38, for example, an actuating drive
38, by means of a control element 39, e.g. a system of adjustable
dampers 39. This allows the temperature of the purified gas stream
08' exiting the heat recovery device 33, which gas will be
discharged downstream, for example, into the environment via, e.g.
a chimney 41, to be varied within limits. This may be necessary in
order to maintain the prescribed dew point limit for the chimney
vent.
[0062] For the aforementioned embodiments and variants of the
device 01 for thermal post-combustion and/or exhaust air treatment
comprising the post-combustion device 01, the burner 04 embodied as
a cone burner 04 according to the invention is configured in a
variant described in the following as having one or more of the
particularly advantageous features set forth in the following.
[0063] The term "burner cone" 06 as used herein does not refer to a
cone as a body in a geometric sense having a regular and e.g.
uninterrupted surface of revolution on the lateral side, and
instead--as is customary in the context of cone burners--refers to
a single-part or multi-part component comprising a single-part or
multi-part conical shroud 43, hereinafter also referred to as wall
43 or wall structure 43, optionally interrupted outwardly by air
through-openings, and laterally bounding a premix chamber 42, the
cross-sectional area of which opens up in the manner of a funnel
toward the outlet (see, e.g. FIG. 4 and FIG. 5). This e.g. wall 43
or wall structure 43, which opens up, at least in one longitudinal
segment, in the manner of a funnel toward the outlet opening of
burner cone 06, can form an irregular inner circumferential line
that deviates from a circular line and is optionally interrupted at
points, as viewed in one or more cross-sections lying perpendicular
to the axial direction of burner 04 (see, e.g. FIG. 6 and FIG. 7).
The space that is surrounded by burner cone 06 or by the wall 43 or
multi-part wall structure 43 thereof forms premix chamber 42, in
which exhaust gas that contains (residual) oxygen can be mixed with
the fuel 03.
[0064] The axial direction of burner 04 is determined, e.g., by the
path of a center of gravity axis or axis of symmetry S of the
burner cone 06, which is configured as rotationally symmetrical or
as at least n-fold (n.epsilon., n>1), e.g. at least two-fold,
radially symmetrical with respect to its side that delimits the
interior space, at least in a longitudinal cone segment that opens
up in the manner of a funnel. Upstream and/or downstream of this
longitudinal segment that opens up, burner cone 06 need not, but
may likewise be embodied as symmetrical in the aforementioned
manner, e.g. as at least radially symmetrical--with regard to at
least the side of its wall 43 or wall structure 43 that delimits
the interior space. In the interest of simplicity, beyond the
configuration of the inner side of the wall, burner cone 06 may
also be embodied as a whole as structurally symmetrical, e.g. at
least radially symmetrical, around the axis of symmetry
S--optionally with the exception of attachments that are irrelevant
in terms of fluid mechanics, such as mountings or necessary
electronics and/or sensors, for example. Radial symmetry or
rotational symmetry in this case is understood as a form of
symmetry in which, when an object is rotated a certain angle around
an axis of symmetry, the object will return to alignment with
itself. With an n-fold radial or rotational symmetry, a
360.degree./n rotation will map the object onto itself.
[0065] Fuel nozzle 07 comprises at least one fuel outlet 44 for
delivering the, e.g. liquid or preferably gaseous fuel 03 into the
premix chamber 42 formed inside burner cone 06. In principle, fuel
nozzle 07 may be embodied as having any geometry with one or more
openings 44 as an outlet or outlets directed toward the premix
chamber. Preferably, however--at least in the region of its end
segment near the cone--it is tubular in configuration and has a
circular discoid or annular opening 44, provided centered on its
front end, forming the fuel outlet 44. In one variant, additional,
optionally smaller openings may be provided, arranged symmetrically
around the central opening 44.
[0066] Fuel nozzle 07 and burner cone 06 are advantageously
arranged relative to one another, as viewed in the axial direction,
such that at least a base segment of burner cone 06, e.g. an
upstream end of wall 43 or a cone base 46 provided specifically for
this purpose, which supports the upstream end of wall 43 or wall
structure 43, surrounds fuel nozzle 07 at least at the level of the
at least one fuel outlet, but preferably at a longitudinal segment
that extends upstream from the fuel outlet, e.g. in the manner of a
sleeve.
[0067] The terms upstream side, upstream, downstream side and
downstream--unless otherwise indicated or obviously otherwise
intended--refer to the direction of flow, as viewed in the axial
direction, of the fuel in the region of fuel nozzle 07 near the
outlet.
[0068] In the case of a cone base 46 provided specifically for this
purpose, said base forms the upstream end-face cover of burner cone
06 and supports the single-part or multi-part wall 43 or wall
structure 43 on the conical shroud side. Otherwise, the upstream
end-face cover of burner cone 06 is formed by the upstream end of
wall 43 or wall structure 43.
[0069] Cone base 46--regardless of its characterization--can be
structurally assigned to fuel nozzle 07, in which case in order to
remove premix chamber 42, the connection between cone base 46 and
wall 43 or wall structure 43 must be separated. Conversely,
however, in a preferred embodiment, cone base 46 may be
structurally assigned to burner cone 06, in which case in order to
remove burner cone 06, the cone base 46 that supports wall 43 or
wall structure 43 must be removed from burner nozzle 07 or from an
attachment 47 of burner nozzle 07 between fuel nozzle 07 and cone
base 46. In addition, to enable further disassembly of burner 04,
cone base 46 may also be detachably connected to wall 43 or wall
structure 43.
[0070] Bottom 49 may be formed by the side, facing the cone
interior, of a cone base 46 embodied as a shroud ring or spoke
ring, which, as viewed in the circumferential direction of fuel
nozzle 07, has a plurality of passages 48 extending predominantly
in the axial direction and/or enabling a predominantly axial
flow--e.g. regions that remain open between spoke-like support
elements or axial through-openings introduced into a ring. In
principle, bottom 49 may also be formed by an intermediate space
that is open around the entire circumference between the upstream
end of wall 43 and fuel nozzle 07 at the axial level or axially
upstream of the fuel nozzle end, if cone 06 is attached, for
example, not to burner nozzle 07 or to a tube segment that
continues this nozzle upstream, but from the outside, e.g. to an
exhaust gas chamber wall or combustion chamber wall.
[0071] A plurality of passages 48 are preferably provided in the
end-face bottom 49 of the burner or burner cone 06, around fuel
nozzle 07 and/or at least around the projection thereof along the
axis of symmetry S, as viewed in the plane that is perpendicular to
the axis of symmetry S. Passages 49 are configured, e.g. such that
they produce a predominantly axial flow upon outlet of the exhaust
air into the cone interior.
[0072] In an advantageous embodiment, cone base 46 is formed by a
component in the manner of an end plate having a preferably annular
opening, which, when installed, receives the preferably tubular
fuel nozzle 07, for example, and is e.g. detachably connected to
fuel nozzle 07 in a force-fitting and/or interlocking connection.
Cone base 46 is preferably embodied as annular and can be
configured in the manner of a clamping ring set, in which case one
of the two clamping rings supports wall 43 or wall structure 43 and
can be frictionally connected by means of a clamping ring to the
outer periphery of fuel nozzle 07.
[0073] Preferably, cone base 46 is formed by an end plate, e.g. in
an embodiment as a flange 46, in particular a flange ring 46, for
example with an annular recess, which flange ring can be connected
to an attachment 47 embodied as a flange 47, in particular a flange
ring 47, arranged, for example, on the periphery of fuel nozzle 07,
flush or preferably with an offset in relation to the nozzle end
face of fuel nozzle 07 (see, e.g. FIG. 8). When installed, cone
base 46, embodied e.g. as a clamping ring or flange 46, is
preferably positioned with its circular opening centered in
relation to the axial direction of burner 04.
[0074] Wall 43 or wall structure 43 is arranged with its upstream
end spaced radially from the lateral surface of the particularly
tubular burner nozzle 07, at least in sections over a portion of
the circumference, advantageously predominantly, and preferably
over the entire circumferential range, so that between the upstream
end of wall 43 or wall structure 43 and burner nozzle 07, at least
in the circumferential direction thereof, an intermediate space
having a distance d, e.g. a distance d of at least 1 mm,
advantageously at least 5 mm, in particular at least 10 mm between
burner nozzle 07 and wall 43 or wall structure 43 is provided in
the radial direction in sections, but preferably around the entire
circumference--with the exception of any supporting and/or
retaining elements that may be provided. Where appropriate, an
annular intermediate space that is freely open or sectionally open
to a flow, e.g. with the exception of any supporting and/or
retaining elements that may be provided, may be formed in this end
region between burner nozzle shroud and wall 43 or wall structure
43, said space having an annular width of, e.g. at least 1 mm,
advantageously at least 5 mm, in particular at least 10 mm. In this
case, the optionally interrupted, freely open intermediate space
represents a passage through which fluid can flow in an end-face
bottom 49 of burner cone 06. Bottom 49 then refers to the narrower
upstream end of burner cone 06, which surrounds the downstream end
of fuel nozzle 07, and together with the latter, forms the upstream
cover of premix chamber 42.
[0075] For the embodiment of an expressly provided cone base 46--in
particular surrounding the tubular burner nozzle 07--said cone base
supports the upstream front end of wall 43 or wall structure 43, at
least sectionally over a portion of the circumference,
advantageously predominantly, and preferably over the entire
circumferential range, spaced radially from the lateral surface of
the particularly tubular burner nozzle 07, so that on the side of
the cone base that faces the premix chamber, at least sectionally
in the circumferential direction of burner nozzle 07, but
preferably over the entire circumference, a distance d in the
radial direction, e.g. a distance d of at least 1 mm,
advantageously at least 5 mm, in particular at least 10 mm is
created between burner nozzle 07 and wall 43 or wall structure
43.
[0076] In an advantageous embodiment illustrated in the diagrams,
in the embodiment with an expressly provided cone base 46, an
annular intermediate space is also provided in this end region
between burner nozzle shroud and the upstream end of wall 43 or
wall structure 43, said intermediate space having an annular width
of, e.g. at least 1 mm, advantageously at least 5 mm, in particular
at least 10 mm. In a preferred embodiment, a plurality of passages
48 that lead into the intermediate space and act e.g. as air inlet
nozzles 48 are provided in the circumferential direction in cone
base 46. Passages 48 lead into the interior of the premix chamber
in bottom 49 or on the end face of the cone base 46, embodied in
particular as an end plate, which end face delimits the bottom 49
on the premix chamber side, within the periphery that is surrounded
by the upstream end of wall 43.
[0077] Passages 48 end, for example, e.g. coming from the upstream
end face of cone base 46, in an intermediate space that is formed
between the upstream end of wall 43 or wall structure 43 and the
fuel nozzle shroud.
[0078] The passages can, in principle, be embodied, e.g. as round
boreholes or in the manner of intermediate spaces formed by
spoke-like braces. In an advantageous embodiment, they are embodied
as rectangular slot-like channels, which creates a guided flow for
the purpose of forming an air cushion or air basket on the inner
side of the wall.
[0079] Burner 04 advantageously has at least one mouth of the at
least one passage 48 leading out of the space 09 that surrounds
burner 04, preferably on the end face, into the cone interior (as
an open ring or as a plurality of passages 48), preferably in an
upstream base segment at the axial height or upstream of the
downstream end of fuel nozzle 07, i.e. depending on its embodiment,
upstream of the tube thereof or the outlet opening 14 thereof.
[0080] The upstream end face of the burner cone 06 or of the premix
chamber formed by burner cone 06 that is without an expressly
provided cone base 46, e.g. is open in an annular shape, with the
exception of any supporting and/or retaining elements that may be
provided, or that is completely closed off as cone base 46, or is
preferably only partially closed off, is also referred to as the
bottom 49 of burner cone 06, and in a preferred embodiment, gaseous
fluid, for example, exhaust air from the raw gas chamber 09, can
flow through said bottom. In this case, a flow component extending
predominantly in the axial direction of burner 04 can flow through
bottom 49, i.e. the vector that characterizes the flow has a
greater directional component in the axial direction as compared
with a radial component. A flow through bottom 49 in the axial
direction without a significant radial component is preferred. In
the aforementioned case of an expressly provided cone base 46, the
exhaust air flows as inlet air through the passages 48 in cone base
46, and otherwise, the exhaust air flows through the intermediate
space which is sectionally open or open around the entire
circumference between wall 43 or wall structure 43 and the burner
nozzle shroud.
[0081] In the embodiment having a cone base 46 configured as a
flange 46, said cone base may be connected via fastening means 49,
e.g. via threaded connectors 49, to the attachment 47, e.g. flange
47, located on fuel nozzle 07. In the case comprising a
flow-through bottom, this attachment 47 is embodied as having a
structure that enables a flow through the passages, e.g. recesses
or passages 52 that are likewise aligned with passages 48.
[0082] Burner 04 is thus configured between the upstream end of the
single-part or multi-part wall of burner cone 06 and the outer
periphery of the burner nozzle 07 that is surrounded by a base
segment of burner cone 06, at the level or upstream of the fuel
nozzle mouth, as having a bottom 49 through which gaseous fluid can
flow at least predominantly in the axial direction. The
predominantly axially extending passage 48 preferably leads from an
end-face opening that leads to the environment to the mouth that is
located in bottom 49.
[0083] In a particularly advantageous refinement of the burner
embodiment in which fluid can flow through in the region of bottom
49, a guide element 51 that is continuous around its entire
circumference, or is multi-part in sections can be positioned
radially between the at least one fuel outlet and the passages, on
a circumferential line that lies further inward radially than the
mouth of the one or more bottom-side passages 48. The guide element
51 or the relevant segment thereof is used to guide the fluid, e.g.
exhaust gas, that is flowing through the respective passage 48 into
a direction angled away from the axis of symmetry S, in the
direction of wall 43 that opens up in the manner of a funnel, where
said fluid forms a lateral surface flow. By means of passages 48
provided around the entire circumference, in conjunction with a
guide element 51, e.g. guide plate 51, arranged sectionally or
continuously around the circumference, an annular lateral flow of
the fluid, e.g. the exhaust gas, out of the raw gas chamber 09 is
formed, protecting wall 43 against overheating under the direct
influence of the burner flame. Guide element 51 is preferably
embodied as a guide plate 51 that extends around the entire
circumference and is embodied, for example, as a frustoconical
shroud that opens up downstream in the axial direction. The slant
angle measured in relation to the axis of symmetry (=one-half the
opening angle) of the guide plate 51 formed, e.g. as a
frustoconical shroud should lie within the range of the preferred
angle range for the conical segment that opens up, e.g. within the
range of 10.degree. to 20.degree., in particular 12.degree. to
16.degree.. The guide element 51 embodied, in particular, as guide
plate 51 extends, as viewed in the axial direction, e.g. at least
at the level of the downstream end of the tubular piece that
delimits the fuel nozzle 07 on the lateral side, over at least a
length of 10 mm, preferably at least 20 mm. This allows the axial
direction of flow to be directed effectively in the direction of
the wall profile once the fluid has exited.
[0084] In the case of a burner cone 06 in which the opening up of
the segment begins only after a straight intake segment, guide
plate 51 is configured as extending first in a tubular fashion over
the length of the straight intake segment, and as then extending
over at least another 10 mm, preferably at least 20 mm, following
the bend of the wall 43.
[0085] The described embodiment in which fluid flows through the
bottom side effects a substantial improvement in a burner 04 for
the post-combustion of exhaust gases, but may be particularly
advantageous with respect to the radially symmetrical and/or
chord-like configuration and/or with respect to taper when combined
with a variant of the embodiment of the conical shroud 43 described
in the following, and/or in conjunction with a variant of the
embodiment of the downstream cone edge that further enhances
turbulence.
[0086] As was already described above, burner cone 06, as a
single-part or multi-part component, comprises a premix chamber 42,
the cross-sectional area of which opens in the manner of a funnel
toward the outlet, over at least a longitudinal cone segment.
Burner cone 06, or the wall 43 thereof, on the longitudinal cone
segment of the cone which is situated downstream of fuel outlet 44
in the axial direction of burner 04, and which opens up in the
manner of a funnel, surrounds and/or encompasses a section of the
premix chamber which has a flow cross-sectional area that increases
in size continuously as the distance from the fuel outlet
increases, and which is measured perpendicular to the axial
direction.
[0087] Burner cone 06, as set forth in this example, can be
embodied as opening up in the manner of a funnel over its entire
length--for example with the exception of a cone base 46 that is
optionally expressly provided for mounting and/or a cover element
53 that is optionally expressly provided for stability and/or
functional purposes. In an embodiment not shown, the burner cone
can comprise an intake segment extending with a constant
cross-sectional area and having a correspondingly shaped wall,
and/or an outlet segment extending with a constant cross-sectional
area and having a correspondingly shaped wall.
[0088] In an alternative embodiment, burner cone 06 can have a
segment that tapers down again, downstream of the segment that
opens up in the manner of a funnel.
[0089] In a first embodiment, wall 43 or wall structure 43 can, in
principle, be embodied in at least the longitudinal cone segment
that opens up--with respect to the inner lateral wall surface
thereof--as integral and/or as rotationally symmetrical around the
axial direction of burner 04 that coincides with the axis of
symmetry. This can be the case regardless of the optionally
provided air through-openings for the wall 43, which in that case
is optionally interrupted at certain points. In this specific,
radially symmetrical case of radial symmetry for wall 43 or wall
structure 43 of burner cone 06, said wall or wall structure extends
in segments spaced axially from one another on circumferential
lines of varying radii, wherein the space surrounded by wall 43 or
wall structure 43 in the longitudinal segment of the cone that
opens up has the shape of a truncated cone and can accommodate a
(virtual) truncated cone of this type that is in physical contact
with the full surface of wall 43.
[0090] In an advantageous second embodiment of the lateral surface
of wall 43 or wall structure 43 of burner cone 06, said lateral
surface, at least in the longitudinal segment of the cone that
opens in the manner of a funnel, has a wall structure that delimits
the premix chamber n-fold radially symmetrically with respect to
the axial direction (with n.epsilon., n.gtoreq.2), at least with a
number of at least 2, i.e. n.gtoreq.2, advantageously with a number
of more than two, i.e. n>2, in particular with a number of at
least 4, i.e. n.gtoreq.4, preferably four, i.e. n=4, and/or is
configured as having n shell-like wall segments 43.1; 43.2; 43.3;
43.4, for example, e.g. what is known as cone leaves 43.1; 43.2;
43.3; 43.4 or simply leaves 43.1; 43.2; 43.3; 43.4, for example, as
n "nth-shells", preferably four quarter shells, arranged radially
symmetrically around the axial direction that forms the axis of
symmetry S.
[0091] In a special case of the second embodiment with radial
symmetry for wall 43 or wall structure 43 of burner cone 06, in a
first variant, the individual shell-like wall segments 43.1; 43.2;
43.3; 43.4 of the multi-part wall structure 43 are arranged with
their sectional lines, as viewed in cross-section, on
circumferential lines if the wall segments are configured as
partial frustoconical shells, or with their sectional lines, as
viewed in cross-section, on a closed polygonal shape of a pyramidal
base if the wall segments are configured as sides of a truncated
pyramid, wherein in the longitudinal segment of the cone that opens
up, the space surrounded by wall 43 or wall structure 43 has the
form of a truncated cone in the first case, and the form of an
m-sided truncated pyramid in the second case (thus in this case,
n=m). In both cases, this inner space defined by wall 43 or wall
structure 43 can thus accommodate a maximum (virtual) truncated
cone, which in the first case is in planar physical contact with
the entire wall 43 or wall structure 43 that surrounds the inner
space, and in the second case is in linear physical contact
therewith along the lateral heights of the sides of the truncated
cone.
[0092] Whether in a rotationally symmetrical or non-rotationally
symmetrical, only radially symmetrical embodiment of the cone
segment that opens up, in an advantageous embodiment, the wall 43
or wall structure 43 that surrounds and/or encompasses the burner
cone 06 outwardly has at least one interruption, in particular a
plurality of interruptions 54, e.g. air or exhaust air inlet
openings 54, over the entire longitudinal cone segment that opens
in the manner of a funnel, or at least a portion thereof, as viewed
in the cross-section extending perpendicular to the axial
direction, through which openings exhaust air to be treated can
flow out of the space surrounding the burner into the interior of
the burner.
[0093] In a preferred embodiment, these exhaust air or air inlet
openings 54 are configured as tangential inlet openings 54 that are
raised radially outward from the circumferential line, to enable a
tangential air inlet of the air or exhaust air that surrounds
burner cone 06. These tangential inlet openings 54, preferably
configured as gaps or slots in the longitudinal direction of burner
06, are preferably formed by a spacing of the edge regions of
adjacent circumferential segments of a single-part or multi-part
wall 43 or wall structure 43, between which inlet opening 54 is
formed, radially from one another in relation to the axis of
symmetry S, at the axial height of an inlet opening 54 in question,
as viewed in the circumferential direction. In principle, these
inlet openings 54 can be formed by an appropriate configuration of
circumferential segments having through-openings and the formation
of a single-part wall 43 or preferably by the geometric arrangement
of individual wall segments 43.1; 43.2; 43.3; 43.4. In that case,
when a negative pressure forms in the interior of the cone, only
air with at least a significant tangential component can be
suctioned in through the inlet openings 54.
[0094] Whether the cone segment that opens up is in a rotationally
symmetrical, a non-rotationally symmetrical, or only a radially
symmetrical embodiment, a--specific or effective "inner"--taper
(i.e. of the maximum truncated cone to be accommodated in the
segment that opens up) having a slant angle .phi. in relation to
the burner axis or axis of symmetry S (=e.g. one-half the opening
angle) of 5.degree. to 15.degree., in particular of 7.degree. to
12.degree., is of particular advantage in terms of fluid mechanics.
In this connection, the inner wall of wall 43 or wall structure 43
of burner cone 06 that delimits the premix chamber outwardly on the
lateral side, at least in the longitudinal cone segment that opens
up in the manner of a funnel, is configured in terms of its shaping
and its structure to accommodate a maximum (virtual) truncated cone
of the greatest possible cross-sectional profile, which is defined
as a cone that is in contact at at least three points, spaced from
one another circumferentially, in each of at least two
cross-sectional planes that are spaced from one another axially,
wherein a surface line of this maximum virtual straight truncated
cone, projected into a sectional plane of burner cone 06 comprising
the axis of symmetry S and extending in the longitudinal direction
of the burner cone, forms a slant angle of 5.degree. to 15.degree.,
particularly of 7.degree. to 12.degree., preferably of
10.degree..+-.1.degree. in relation to the axial direction or the
axis of symmetry S.
[0095] In a preferred second variant of the second embodiment of
the configuration of wall 43 or wall structure 43 of burner cone 06
described here, having an n-fold radially symmetrical
circumferential profile, in the longitudinal cone segment that
opens up, the circumferential segments u1; u2; u.3; u.4 formed by
the individual wall segments 43.1; 43.2; 43.3; 43.4 of a
single-part or more particularly a multi-part embodiment of wall
43, as viewed in the cross-section extending perpendicular to the
axial direction, in contrast to the first variant, do not follow
the same circumferential line K1; K2; K1'; K2' or closed polygonal
shape, at least not over their entire length, and instead, the
mutually adjacent circumferential section ends of two wall segments
43.1; 43.2; 43.3; 43.4 that adjoin one another in the
circumferential direction are offset radially relative to one
another. The radial offset of the adjacent circumferential segment
ends, which overlap or at least continue without gaps, for example,
in the angle range around the axis of symmetry S, forms tangential
air or exhaust air inlet openings 54 by means of which a swirl
formation is stimulated in the interior of the cone.
[0096] Burner cone 06, at least in the burner cone segment of wall
43 that opens up in the manner of a funnel, thus preferably
comprises n, e.g. more than two, or even at least four tangential
inlet openings 54 that are formed by the fan-like arrangement, for
example, of the preferably (partially) shell-like wall segments
43.1; 43.2; 43.3; 43.4, spaced from one another in the
circumferential direction, and each raised radially--in particular
outwardly--away from the preceding circumferential shroud segment,
to create a tangential air inlet of the exhaust air surrounding
burner cone 06.
[0097] In a particularly advantageous embodiment of wall segments
43.1; 43.2; 43.3; 43.4 of the second variant, in which said wall
segments have a shell-like shape, e.g. they are shaped as a partial
frustoconical shell or as a side of a truncated pyramid, or have
some other shape, the n wall segments 43.1; 43.2; 43.3; 43.4 that
are offset radially symmetrically are arranged each rotated about a
respective imaginary axis that extends parallel to the axial
direction or to the axis of symmetry S in relation to an
orientation that forms a closed frustoconical shell structure or
frustopyramidal shroud structure. In this case, e.g. all of the
axes intersect a circumferential line extending concentrically
around the axis of symmetry S, spaced equidistant from one another
in the circumferential direction. Such a rotated arrangement of
wall segments 43.1; 43.2; 43.3; 43.4, which otherwise have the same
configuration, results in a fan-like conical lateral surface in the
circumferential direction.
[0098] In an advantageous embodiment of this type, the partial
conical axes of the wall segments 43.1; 43.2; 43.3; 43.4 embodied
as partial conical shells do not lie on a common conical axis, so
that each of the aforementioned tangential inlet openings 54, in
its cross-section that opens up on the exterior of wall 43, is
raised radially from the circumferential shroud segment preceding
it, as viewed in the circumferential direction.
[0099] In a specific advantageous variant of this embodiment, wall
segments 43.1; 43.2; 43.3; 43.4 are embodied as shroud segments
43.1; 43.2; 43.3; 43.4 of identical size that make up a conical
shroud which is embodied as radially symmetrical and has a closed
profile, e.g. as a frustoconical shroud or e.g. as an I-fold
(I.epsilon., I.gtoreq.n, e.g. I=n*m) frustopyramidal shroud, in
which each such shroud segment is rotated by the same angle in
relation to an aforementioned respective axis--e.g. parallel to the
axis of symmetry S. Each of these shroud segments 43.1; 43.2; 43.3;
43.4 can be lengthened slightly in the circumferential direction
relative to its length in the closed form (see angle .delta.), so
that the shroud segments 43.1; 43.2; 43.3; 43.4 that are rotated in
this manner in the circumferential angle with respect to the axis
of symmetry S at least continue directly or advantageously overlap
slightly.
[0100] In the case of the wall 43 or wall structure 43 which, in
the second variant, does not extend in the cross-section of the
segment that opens up entirely along a circumferential line K1; K2;
K1'; K2' in each cross-section of the opening cone segment that has
the circumferential segments, and which has, e.g. wall segments
43.1; 43.2; 43.3; 43.4 arranged in a fan-like manner as described
above and/or rotated circumferentially, and/or in the case in which
the shaping of the wall segments 43.1; 43.2; 43.3; 43.4 in the
circumferential direction results in the aforementioned differently
angled lateral surface lines relative to the axis of symmetry S, in
a first method for characterizing taper that does not consider the
degree of radial offset of the adjacent circumferential segment
ends and/or the degree of the aforementioned rotation, and/or a
twisting of wall segments 43.1; 43.2; 43.3; 43.4, the greatest
possible cross-sectional profile may be used as the taper that is
effective for the swirling movement and/or the proximity to the
flame in a first approximation of the aforementioned maximum
(virtual) internal truncated cone, as was defined above in
connection with the first variant. This virtual truncated cone
corresponds to the greatest possible concrete straight truncated
cone that can be inserted into the segment of the cone that opens
up, and may at the same time correspond to the minimum effective
slant angle .phi.1 of the most acute truncated cone, as defined in
the following embodiment.
[0101] Regarding a further characterization, optionally in addition
to the aforementioned characterization based on the maximum
possible inner truncated cone in question, for the configuration of
the burner cone 06 embodied as radially symmetrical in a fan-like
manner, the most acutely tapered virtual truncated cone, which is
determined by the inwardly directed regions of wall 43 of each wall
segment with the smallest slant angle, and also the most obtusely
tapered virtual truncated cone, which is determined by the inwardly
directed regions of wall 43 that have the greatest slant angle
relative to the axis of symmetry S, may both be used.
[0102] Here, a particular advantageous embodiment of burner cone 06
is one in which wall segments 43.1; 43.2; 43.3; 43.4 of burner cone
06, in the region of the wall 43 or wall structure 43 that bounds
premix chamber 42 outwardly, are configured in terms of their
shaping and their structure, at least in the longitudinal cone
segment that opens up--in a quasi-funnel shape--such that the
sharpest virtual truncated cone has a cone angle or opening angle
of at least 10.degree., advantageously at least 14.degree., i.e. a
surface line that extends in this longitudinal cone segment that
opens up in the manner of a funnel, in the longitudinal direction
of the burner cone on the inside of the same wall segment, and is
slanted the smallest degree in relation to the axial direction,
forms an slant angle of at least 5.degree., preferably at least
7.degree., with the axial direction in a vertical projection in a
sectional plane that comprises the axial direction, however in this
embodiment, said surface line lies below that of the more obtusely
angled truncated cone. In an embodiment of this type, having a
varying slant in the circumferential direction of the shells, has a
maximum cone angle or opening angle of, e.g. no more than
50.degree., advantageously no more than 40.degree., i.e. a surface
line that extends in this longitudinal cone segment that opens up
in the manner of a funnel, in the longitudinal direction of burner
cone 06 on the inside of the wall segment, and is slanted the
greatest degree in relation to the axial direction, the more
obtusely angled virtual truncated cone forms a maximum slant angle
of, e.g. no more than 25.degree., advantageously no more than
20.degree., with the axial direction in a vertical projection on a
sectional plane that comprises the axial direction.
[0103] A "mean" taper or a mean slant angle .phi.* that can be used
in this way to obtain a more specific geometric characterization is
determined, for example, by averaging. The averaging is determined,
for example, by integral averaging along the circumferential
direction of the slant of all surface lines, i.e., weighted over
the circumferential length in question, corresponds to the mean
that results from sweeping over a plane that extends through the
axis of symmetry S along the circumferential segment in question,
e.g. the 360.degree. circumference, or the angle range encompassed
by the wall segment in question, on the inner side of wall 43 or
wall structure 43. This averaged slant can advantageously measure
10.degree. to 20.degree., more particularly 12.degree. to
17.degree..
[0104] In the embodiment of burner wall 43 in which the wall
segments 43.1; 43.2; 43.3; 43.4 are embodied, as described above,
in the form of shroud segments of a radially symmetrical truncated
pyramid or truncated cone that are rotated relative to one another,
the integral mean corresponds to the arithmetic mean, for
example.
[0105] In the fan-like embodiment having two surface lines with
different slants and/or having shroud segments 43.1; 43.2; 43.3;
43.4 that are each rotated relative to the others around the axial
direction, wall segments 43.1; 43.2; 43.3; 43.4 each have, in the
region of a first end as viewed in a circumferential direction of
burner cone 06, a first lateral surface line extending in the
longitudinal direction of burner cone 06 which is slanted in
relation to the axial direction at, e.g. a first slant angle, e.g.
the smaller slant angle .phi.1, and in the region of a second end
with respect to the circumferential direction of burner cone 06,
each have a second lateral surface line extending in the
longitudinal direction of burner cone 06 which is slanted in
relation to the axial direction at, e.g. a second slant angle, e.g.
the greater slant angle .phi.2.
[0106] In an embodiment which is advantageous for the fan-like
configuration, the slant angles at the two points of greatest
deviation differ from one another by a maximum of 5.degree.,
advantageously by a maximum of 3.degree..
[0107] In the longitudinal cone segment of burner cone 06 (cone
segment) that opens downstream in the manner of a funnel, a
plurality, e.g. the number n, of such wall segments 43.1; 43.2;
43.3; 43.4 in which the first and second ends are slanted
differently are thus arranged staggered in the circumferential
direction of burner cone 06 in such a way that, as viewed in the
circumferential direction of burner cone 06, a less steeply slanted
second end of a first wall segment 43.1; 43.2; 43.3; 43.4 that
extends over a first angle range, e.g. 360.degree./n, optionally
plus a slight intersection .delta. (.delta. being from 1.degree. to
5.degree.), in particular 90.degree. or 90.degree.+.delta., is
continued by a first end of a second wall segment 43.2; 43.3; 43.4;
43.1 which is slanted more steeply than the second end of the first
wall segment 43.1; 43.2; 43.3; 43.4, and which adjoins the first
angle range without gaps or with a slight angular overlap .delta.
(intersection) with respect to the angle in relation to the burner
longitudinal axis as the center. The angle segments that are
covered with respect to the axis of symmetry S by the respectively
adjacent wall segments 43.1; 43.2; 43.3; 43.4 in the
circumferential direction thus continue at least without gaps, or
even overlap one another slightly as described above. This prevents
a purely radial flow--with respect to the axis of symmetry
S--through the tangential inlet openings 54 that are formed between
the adjacent wall segments 43.1; 43.2; 43.3; 43.4. In this case,
the first end of the second wall segment 43.2; 43.3; 43.4; 43.1,
for example in at least one downstream end segment of the
longitudinal cone segment that opens up downstream in the manner of
a funnel, is spaced further radially from the longitudinal axis of
the burner than the second end of the first wall segment 43.1;
43.2; 43.3; 43.4.
[0108] In the region of cone base 46, the cone leaves 43.1; 43.2;
43.3; 43.4 arranged adjacent to one another in a fan-like manner
may converge at their end segments or, as in the advantageous
embodiment shown, for example, may border the cone bottom 49,
spaced radially from one another. In the first case, the area
between the adjacent cone leaves 43.1; 43.2; 43.3; 43.4 is closed
down to the bottom 49, and in the preferred second case, a
tangential air inlet or exhaust air inlet opening 54 is formed
between the adjacent cone leaves 43.1; 43.2; 43.3; 43.4 down to the
bottom 49, however the gap width of said opening may taper down to
the bottom.
[0109] FIG. 6 and FIG. 7 illustrate the circumstances of the
described embodiment having a varying slant for the second variant,
with FIG. 7 showing, in a schematic diagram of two cross-sections
I-I; II-II, spaced from one another in the axial direction (see,
e.g. FIG. 6), of the longitudinal cone segment that opens up, an
inner lateral surface M1; M2 of a virtual truncated cone indicated
by circumferential lines K1 and K1', and an outer lateral surface
of a virtual truncated cone indicated by circumferential lines K2
and K2'. FIG. 6 shows, for example, in the case of a rotationally
symmetrical burner cone embodiment, a smaller slant angle .phi.1
provided by way of example for an inner virtual truncated cone,
which as the "effective" slant angle may correspond to an actual
slant angle .phi., for example in the case of rotational symmetry,
a larger slant angle .phi.2 provided by way of example for an outer
virtual truncated cone, and a mean slant angle .phi.* obtained by
way of example from an aforementioned averaging.
[0110] Cone 06 is preferably embodied as having an effective or
mean slant of this type, so that the effective or mean inner radius
or inner diameter that is obtained therefrom increases in size from
the upstream end to the downstream end of the funnel-shaped cone
segment by a factor of 4.8 to 5.8, in particular of 5.0 to 5.5. For
example, cone 06 may be embodied as having an effective or mean
diameter of 500 mm to 700 mm, in particular of 550 mm to 650 mm, at
the downstream cone end of its funnel-shaped longitudinal
segment.
[0111] For the aforementioned advantageous case of a conical shroud
embodied as shroud segments 43.1; 43.2; 43.3; 43.4 of a radially
symmetrical shroud that has a closed profile--optionally with an
extension in the circumferential direction to form the closed angle
range and optionally with an overlap--wall segments 43.1; 43.2;
43.3; 43.4 are formed by shroud segments 43.1; 43.2; 43.3; 43.4 of
equal size forming an e.g. I-sided straight frustopyramidal shroud
or a straight frustoconical shroud, with the slant of the pyramidal
side surfaces in relation to the axial direction in the first case,
and the slant of the frustoconical lateral surface in the second
case preferably corresponding to that of the aforementioned actual
or effective slant angle .phi., i.e. 5.degree. to 15.degree., in
particular 7.degree. to 12.degree.. The rotation, for example, by
3.degree. to 10.degree., about the axis in each case results in the
difference in the slant .phi.1; .phi.2 in relation to the axis of
symmetry S or the axial direction of burner cone 06 or burner 04,
at the two circumferential ends of the shroud segment 43.1; 43.2;
43.3; 43.4 relative to one another, caused by the rotation.
[0112] Both for the actual truncated cone in a radially symmetrical
embodiment, and for the maximum virtual inner truncated cone, the
inner wall 43 of burner cone 06 that delimits premix chamber 42
outwardly on the lateral side, at least in the longitudinal cone
segment that opens up in the manner of a funnel, is preferably
configured in terms of its shape and its structure to accommodate a
maximum virtual truncated cone having the largest possible
cross-sectional profile, which cone is in contact with wall 43,
e.g. at at least three points, spaced from one another
circumferentially, in each of at least two cross-sectional planes
that are spaced from one another axially, and the lateral surface
line extending on the frustoconical lateral surface of this maximum
virtual truncated cone in its longitudinal direction forms a slant
angle of 5.degree. to 15.degree., preferably of 7.degree. to
12.degree., with the axis of symmetry S, which slant angle is
constant in the circumferential direction.
[0113] The ends of the shroud segments 43.1; 43.2; 43.3; 43.4 that
adjoin one another circumferentially, but the end regions of which
are spaced from one another radially, may be partially connected to
one another via supporting elements 68, thereby increasing the
stability of the cone structure.
[0114] In principle, the n circumferential segments u1; u2; u.3;
u.4 of the wall segments 43.1; 43.2; 43.3; 43.4 or shroud segments
43.1; 43.2; 43.3; 43.4, as viewed in the circumferential direction,
can be formed by a homogeneous component having a curved profile
that is curved without kinks in the cross-sectional plane that
extends perpendicular to the axial direction.
[0115] Downstream, burner cone 06 can be capped off by a cover
element 53 that is connected--in particular in a bonded or
interlocking connection--to wall 43 or wall structure 43, e.g. a
cover plate 53 that surrounds the opening. This cover plate 53 may
be embodied solely for reinforcement purposes and/or for forming an
edge 62 or edge region 62 that surrounds the end-side outer contour
of wall 43 or wall structure 43 in the manner of a collar.
Alternatively or additionally, cover plate 53 may be arranged
and/or embodied as covering the downstream end of the tangential
air or exhaust air inlet openings 54 that are formed between the
wall segments 43.1; 43.2; 43.3; 43.4, which are adjacent in the
circumferential direction. An edge 62 configured in this manner can
be used to enhance the swirling of the air or exhaust air entering
the combustion chamber 11 through the inlet gap 18, and an end-face
covering 61 of the air inlet or exhaust air inlet openings 54 can
be used to enhance the tangential flow.
[0116] In an embodiment of burner cone 06 which is advantageous in
principle, e.g. in terms of manufacturing, regardless of the
remaining configuration of the wall 43 or wall structure 43 and/or
of the flow capacity on the bottom side, but which is particularly
advantageous when combined with other specified features, said
burner cone is formed in the circumferential direction by a number
of individual planar segments, e.g. guide panels, more particularly
flat sheet metal strips, which are all connected, or which are
connected in groups, in a bonded or interlocking connection in the
circumferential direction, wherein e.g. a curvature is created by a
slanted joint between two adjacent joined segments. The segments,
which are all connected or are connected in groups, are
connected--in particular in a bonded or interlocking
connection--e.g. in the region of the upstream end to, e.g. the
cone base 46 and/or in the region of the downstream burner cone
end, for example, to cover element 53, e.g. to a cover plate 53
that surrounds the opening. Cover plate 53 may be embodied for
reinforcement purposes.
[0117] In the cone segment that opens up in the manner of a funnel,
wall 43 or wall structure 43 has in the circumferential direction a
plurality of planar segments, e.g. flat sheet metal strips,
extending longitudinally along burner 04 at an angle relative to
the axial direction of burner 04, thereby forming circumferential
segments that extend in a chord-like manner, as viewed in
cross-section.
[0118] In an embodiment that is advantageous, e.g. in terms of
production engineering, for the embodiment that comprises a number
n of wall segments 43.1; 43.2; 43.3; 43.4, the wall segments 43.1;
43.2; 43.3; 43.4 are in turn formed in the circumferential
direction by a number m of individual segments 43.1x; 43.2x; 43.3x;
43.4x (see, e.g. FIG. 7b), in which x=2 to m, m.epsilon., m>1,
e.g. m>3, in particular n.gtoreq.5). The m segments 43.1x;
43.2x; 43.3x; 43.4x are interconnected and are connected in the
region of their upstream end, for example, to cone base 46 and/or
in the region of the downstream burner cone end, for example, to a
cover element 53--in particular via bonded or interlocking
connections.
[0119] For the aforementioned advantageous case in which wall
segments 43.1; 43.2; 43.3; 43.4 are configured as shroud segments
43.1; 43.2; 43.3; 43.4 of a radially symmetrical conical shroud
that has a closed profile, the n shroud segments 43.1; 43.2; 43.3;
43.4 of a truncated pyramid, for example, in turn comprise segments
43.1x; 43.2x; 43.3x; 43.4x, in which case the part of the
description relating to the slant of the pyramidal side surfaces
may be applied, e.g. to the slant of these partial surfaces. In
that case, the conical shroud is then formed substantially--i.e.
optionally plus the aforementioned slight addition in the
circumferential direction--by the shroud segments 43.1; 43.2; 43.3;
43.4 of a regular or irregular truncated pyramid having I=n*m side
surfaces, with I equal or at least partially geometrically distinct
frustopyramidal sides.
[0120] In an embodiment of burner cone 06 that is fundamentally
advantageous in terms of, e.g. fluid mechanics, regardless of the
remaining configuration of wall 43 or wall structure 43 and/or
regardless of the flow-through capacity on the bottom side, and/or
regardless of a turbulence enhancement as described in the
following, but which is particularly advantageous when combined
with additional specified features, wall 43 or wall structure 43
can comprise, in its wall surface that encloses the inner space,
axial air inlet or exhaust air inlet openings 56; 57 which are
different from optional tangential air inlet openings 54, and which
are embodied as, e.g. round boreholes 56 or as recesses 57
configured as having a slot-like profile, through which at least
also fluid having a flow direction directed purely radially to the
axis of symmetry S can flow. It is also possible for both types of
air inlet or exhaust air inlet openings 56; 57 to provided. In
addition, exhaust air inlet openings 56; 57 may be provided,
preferably exhaust air inlet openings 57 that are configured in the
form of slots and that have partial covers 58, e.g. dampers 58,
which are braced outwardly along the edge. These dampers 58 may
correspond, for example, substantially to the shape of the relevant
exhaust air inlet openings 56; 57, and the angle of these dampers
relative to the surrounding closed shroud surface may be adjustable
for the purpose of adjusting the flow of air or exhaust air passing
through, e.g. they may be bendable along the connection that exists
along one side of the exhaust air inlet opening 56; 57, on the edge
of damper 58.
[0121] The radial air inlet or exhaust air inlet openings 56; 57 in
wall 43 or wall structure 43 act as inlet air injectors, and also
contribute to the formation of the air cushion or air basket and/or
to the infeed of oxygen on the inner wall side.
[0122] In principle independently of, and advantageously in
combination with one or more of the aforementioned advantageous
features of burner 04 is the embodiment of the configuration of the
downstream cone end, as viewed in the axial direction of burner 04,
that enhances the turbulence of the fluid stream, in particular the
exhaust air stream 02, flowing past the outside of burner 04, in
which said cone end has a plurality of first and/or second flow
restrictors 59; 63; 64; 66, extending out of the profile which is
determined by the end-side contour of the single-part or multi-part
conical shroud 43 that surrounds the premix chamber, and optionally
by the cover 61 that protrudes in the manner of a collar and is
present in the plane of outlet opening 13 of burner cone 06, and
into the space that surrounds the burner cone 06, in particular
into the inlet gap 18 toward the combustion chamber 11 situated
downstream, and spaced from one another in the circumferential
direction of burner cone 06. These flow restrictors can, in
principle, themselves be formed or attached directly in the region
of the front end face to the wall of the wall 43 or wall structure
43 that forms the conical shroud.
[0123] The function of the flow restrictors 59; 63; 64; 66 is to
effectively mix the hot combustion gases from the flame with the
inlet air flowing outside the burner 04, through the inlet gap 18
and into combustion chamber 11. The flow restrictors 59; 63; 64; 66
extending at a slant or flat in relation to the plane of outlet
opening 16, and embodied e.g. as guide vanes 59; 63; 64; 66 thereby
disruptively break up the stream of air flowing through the inlet
gap 18 and/or the substantially rotationally symmetrical conical
flow in burner cone 06, and with it the substantially rotationally
symmetrical flame, thereby mixing the gas stream from inside the
burner with the gas stream from inlet gap 18.
[0124] In an advantageous embodiment of burner cone 06 that is
particularly advantageous, e.g. when combined with the fan-like
configuration, flow restrictors 59; 63; 64; 66 that project outward
from the profile are integrally formed onto cover plate 53 that
caps off the downstream end of burner cone 06, or are attached to
said cover plate in an interlocking or bonded connection.
[0125] Flow restrictors 59; 63; 64 that are formed on or attached
to the conical shroud or to cover plate 53 are formed, e.g. as
guide vanes 59; 63; 64 made of flat sheet metal material, and are
embodied as planar or as having at least one planar portion; they
are preferably arranged with the planar portion, or with at least
one of the planar portions, slanted in relation to the plane of
outlet opening 16, which is perpendicular to the axial direction.
For example, the flow restrictors 59; 63; 64 embodied as guide
vanes 59; 63; 64 can be embodied as integral with or connected
along one of their side edges to cover plate 53, such that the flow
restrictors can be bent to a greater or lesser degree in order to
adjust the turbulence.
[0126] For example, first flow restrictors 59 embodied as flat
guide vanes 59 can be arranged with one edge on an edge section of
the portion of the cover plate 62 that caps off the tangential air
inlet or exhaust air inlet openings 54 at the front end.
[0127] Alternatively or additionally, second flow restrictors 63;
64 embodied as flat guide vanes 59 can be arranged with one edge on
an edge section of the portion of the cover plate 62 that covers
wall 43 or wall structure 43 in the region of wall segments 43.1;
43.2; 43.3; 43.4.
[0128] Guide vanes 59; 63; 64, in particular the first guide vanes
59, may, in principle, all point outward, upstream or downstream,
from the plane of the outlet opening 16; preferably, however, some
of said guide vanes point upstream and some downstream. Guide vanes
59; 63; 64, in particular the second guide vanes 63; 64, may be
arranged as a pair of guide vanes 63, 64 on the two sides, as
viewed in the circumferential direction, of a segment 66 that
extends outward radially from the periphery of the cover plate 62,
with e.g. one guide vane pointing outward and downstream from the
plane of outlet opening 16, and the other pointing upstream.
[0129] The aforementioned device 01 for thermal aftertreatment
comprises burner 04 in one of the aforementioned embodiments, with
one or with a combination of several of the features highlighted
above as advantageous.
[0130] In a refinement of device 01, combustion chamber 11 has in
its interior a turbulence generating device 67, for example, a
baffle plate 67, assigned to the chamber. The turbulence generating
device 67 embodied as a baffle plate 67 extends, e.g. parallel to
the plane of outlet opening 16 of burner 04 and substantially
centrically to the axial direction of burner 04.
[0131] While a preferred embodiment of a device comprising an
industrial system and a post-combustion device in accordance with
the present invention has been set forth fully and completely
hereinabove, it will be apparent to one of skill in the art that
changes can be made to the present invention, without departing
from the true spirit and scope of the invention which is
accordingly to be limited only by the appended claims.
* * * * *