U.S. patent application number 10/110070 was filed with the patent office on 2003-01-30 for atomizing burner.
Invention is credited to Mittmann, Bernd, Sallinger, Christine, Wolf, Felix.
Application Number | 20030022123 10/110070 |
Document ID | / |
Family ID | 7652045 |
Filed Date | 2003-01-30 |
United States Patent
Application |
20030022123 |
Kind Code |
A1 |
Wolf, Felix ; et
al. |
January 30, 2003 |
Atomizing burner
Abstract
The invention relates to an atomizing burner, especially for use
in an automobile auxiliary heating system, comprising an atomizing
nozzle (2) for processing the fuel, an ignition device (29) and a
combustion chamber (8). An iar conduction device (10, 12, 14) is
connected upstream of a nozzle holder (3) of the atomizing nozzle
(2) in order to achieve finer atomization of the fuel. Said air
conduction device subjects the combustion air streaming into the
atomizing nozzle (2) to a swirl.
Inventors: |
Wolf, Felix; (Augsburg,
DE) ; Mittmann, Bernd; (Germering, DE) ;
Sallinger, Christine; (Unterschleissheim, DE) |
Correspondence
Address: |
NIXON PEABODY, LLP
8180 GREENSBORO DRIVE
SUITE 800
MCLEAN
VA
22102
US
|
Family ID: |
7652045 |
Appl. No.: |
10/110070 |
Filed: |
July 18, 2002 |
PCT Filed: |
August 6, 2001 |
PCT NO: |
PCT/EP01/09065 |
Current U.S.
Class: |
431/354 ;
239/463; 239/468; 239/472 |
Current CPC
Class: |
F23D 11/103 20130101;
F23C 2900/07001 20130101 |
Class at
Publication: |
431/354 ;
239/463; 239/468; 239/472 |
International
Class: |
F23D 014/02 |
Foreign Application Data
Date |
Code |
Application Number |
Aug 6, 2000 |
DE |
100 39 152.4 |
Claims
1. Atomizer burner, especially for use in motor vehicle auxiliary
heating systems, with an atomizer nozzle (2) for preparing the
fuel, an ignition means and a combustion chamber (8), characterized
in that the air-guiding means (10, 10') is connected upstream of
the burner nozzle assembly (3) of the atomizer nozzle (2) and
swirls the combustion air flowing into the atomizer nozzle (2).
2. Atomizer burner as claimed in claim 1, wherein the air-guiding
means (10) has swirl blades (17).
3. Atomizer burner as claimed in claim 2, wherein the swirl blades
(17) are located on a carrier (12) which is mounted on the burner
nozzle assembly (3) and wherein two swirl blades (17) at a time
together with the carrier (12) and the burner nozzle assembly (3)
form a conical channel (19).
4. Atomizer burner as claimed in claim 1, wherein the air-guiding
means (10') has a pot-shaped sleeve (30) which is mounted on the
burner nozzle assembly (3) with axial air openings (32) formed in
it and peripheral air openings (34, 35) formed in the peripheral
wall (33).
5. Atomizer burner as claimed in claim 4, wherein the peripheral
air openings (34) are holes formed almost tangentially to the
peripheral wall (33).
6. Atomizer burner as claimed in claim 4 or 5, wherein there are
air guide blades (36) on the peripheral air openings (35).
7. Atomizer burner as claimed in one of claims 4 to 6, wherein the
axial air openings (32) and the peripheral air openings (34; 35)
are matched to one another such that a defined swirl is imparted to
the combustion air.
8. Atomizer burner as claimed in one of claims 4 to 7, wherein the
sleeve (30) is connected by form-fit to the burner nozzle assembly
(3).
9. Atomizer burner as claimed in one of claims 4 to 7, wherein the
sleeve (30) is connected by force-fit to the burner nozzle assembly
(3).
10. Atomizer burner as claimed in one of claims 4 to 7, wherein the
sleeve (30) is slipped onto the burner nozzle assembly (3).
11. Atomizer burner as claimed in one of the preceding claims,
wherein the atomizer nozzle (2) has an internal cross section which
has a static pressure profile over its run which has at least
directly around the outlet opening (13) of the fuel from the fuel
feed (11) its minimum, resulting in a high flow velocity which
tears the fuel out of the fuel feed (11) and atomizes it.
12. Atomizer burner as claimed in one of the preceding claims,
wherein the atomizer nozzle (2) is a Venturi nozzle.
Description
[0001] This invention relates to an atomizer burner, especially for
use in a motor vehicle auxiliary heating system, with an atomizer
nozzle to prepare the fuel, an initiation means, and a combustion
chamber.
[0002] In the most varied applications, for example the area of
fuel-fired heaters as heaters for a motor vehicle or auxiliary
heating systems for motor vehicles it is necessary to prepare the
liquid fuel which is to be burned for example in a burner and to
bring it into a state suitable for combustion.
[0003] A known device which is used especially in auxiliary heating
systems for motor vehicles or other mobile units contains an
absorbent body, for example a nonwoven to which liquid fuel is
supplied by a fuel supply line. The fuel supplied to this absorbent
body vaporizes as the combustion air flow is delivered and can then
be ignited using for example a glow plug.
[0004] In spite of the advantages of this simple type of
gasification of liquid fuels, this device also has disadvantages.
Thus, in these vaporizers which are used in burner devices,
considerable time is required until a usable flame has formed,
adversely affecting the response times of burners equipped with one
such vaporizer.
[0005] To circumvent these defects, atomizer burners have been
developed in which the vaporizer means is replaced by an atomizer
nozzle. But it has been shown that the atomizer nozzles used in
atomizer burners cannot effect the required atomization in every
case.
[0006] The object of this invention is therefore to devise an
atomizer burner which enables high-quality atomization of the fuel
for quick response times of the burner and high efficiency thereof
and which can be operated and produced easily and economically.
[0007] This object is achieved in a generic atomizer burner as
claimed in the invention in that upstream of the burner nozzle
assembly of the atomizer nozzle an air-guiding means is connected
which swirls the combustion air which flows into the atomizer
nozzle. By swirling this nozzle air the atomization quality and
thus the efficiency of the atomizer burner can be greatly improved
since the combustion air velocity and nozzle air velocity are
additionally increased as a result of the impressed tangential
motion component.
[0008] Advantageous embodiments of the invention are given in the
dependent claims.
[0009] When a Venturi diffusor is connected downstream of the
arrangement, its opening angle advantageously increases with
increasing swirl.
[0010] In one preferred embodiment the air-guiding means has swirl
blades which impress a swirl on the combustion air flow on its path
to the atomizer nozzle.
[0011] It is advantageously provided that the swirl blades are
located on a carrier mounted on the burner nozzle assembly and that
two swirl blades at a time together with the carrier and the burner
nozzle assembly form a conical channel. Depending on the angle
adjustment of these swirl blades to one radial plane at a time the
tangential air proportion and thus the nozzle air swirl can be
adjusted. The swirl blades can be arranged roughly radially or
essentially tilted to the radial. The swirl blades can be made
planar or curved in the flow direction.
[0012] According to one alternative preferred embodiment it is
provided that the air-guiding means has a pot-shaped sleeve with
axial holes and tangential holes made in it and that the sleeve is
mounted on the burner nozzle assembly, and the mounting can be made
form-fitted or force-fitted. Alternatively the sleeve can be
slipped onto the burner nozzle assembly.
[0013] The axial and tangential holes are matched to one another
such that a defined swirl is imparted to the combustion air. The
swirl can thus be determined by the choice of size, arrangement and
execution of the tangential and axial holes to one another with
respect to its characteristics.
[0014] Preferably the atomizer nozzle has an internal cross section
which has a pressure profile over its run which at least directly
around the outlet opening of the fuel from the fuel feed shows a
value which is reduced compared to the pressure prevailing in the
fuel feed. The amount of pressure reduction is chosen such that the
fuel is sucked out of the fuel feed and is atomized in doing so.
The internal cross section of the atomizer nozzle is feasible made
as a Venturi nozzle.
[0015] Other properties and advantages of this invention follow
from the description of preferred embodiments with reference to the
attached drawings.
[0016] FIG. 1 shows in a schematic lengthwise cross sectional view
one preferred embodiment of an atomizer burner as claimed in the
invention;
[0017] FIG. 2 shows in a perspective view the air-guiding means of
the atomizer burner of FIG. 1;
[0018] FIG. 3 shows in a schematic lengthwise cross sectional view
a second preferred embodiment of an atomizer burner as claimed in
the invention;
[0019] FIG. 4 shows in a schematic cross sectional view along line
A-A in FIG. 3 the air-guiding means of the embodiment as shown in
FIG. 3; and
[0020] FIG. 5 shows in a schematic cross sectional view as shown in
FIG. 4 an alternative embodiment of the air-guiding means.
[0021] An atomizer burner which is intended especially for use in a
motor vehicle auxiliary heating system contains (see FIG. 1) an
atomizer burner 2 with a burner nozzle assembly 3, fuel supply 4
for feeding fluid fuel to the atomizer area 6 of the atomizer
nozzle 2 and a combustion chamber 8 which is surrounded by a heat
shield 9 as the peripheral boundary. Upstream of the burner nozzle
assembly 3 of the atomizer nozzle 2 an air-guiding means 10 is
connected; it impresses a swirl on the nozzle air flowing into the
atomizer nozzle 2. In the embodiment shown in FIG. 1 the atomizer
nozzle 2 is made as a Venturi nozzle which has an air inflow
channel 5 and an atomizer area 6 which widens in the flow direction
and through which flows the atomizer air flow which flows into the
atomizer nozzle 2 via the air-guiding means 10. A fluid or fuel
feed 11, for example a fuel needle, projects into the air inflow
channel 5 of the atomizer nozzle 2 (see also FIG. 2) and has a
specifically arranged outlet opening 13. The fuel feed 11 is
located preferably on the middle axis 7 of the atomizer nozzle 2 or
of the air inflow channel 5 and of the atomizer area 6 of the
Venturi nozzle.
[0022] If a combustion air flow flows through the atomizer nozzle
2, within the atomizer nozzle 2 a pressure profile builds up, in
the air inflow channel 5 first a high static pressure prevailing
which decreases in the flow direction to the atomizer area 6 and
which at the outlet opening 13 of the fuel feed 11 for the fuel to
be atomized has reached its minimum. The fuel delivered from the
fuel feed 11 to the outlet opening 13 is intaken for this reason
such that upon emerging from the outlet opening 13 of the fuel feed
11 it is broken up by the high air velocity at this point and is
thus atomized. The fuel feed 11 can be a line, a fuel needle, or a
fluid nozzle in order to deliver the fuel to be atomized almost
unpressurized to the Venturi nozzle.
[0023] Since the atomizer nozzle 2 according to the embodiment of
the burner shown in FIG. 1 is exposed to high thermal loads, it is
preferably made of ceramic. Compared to steel a ceramic material as
an alternatively usable material has important thermomechanical
advantages such as lower thermal conductivity and lower coefficient
of thermal expansion.
[0024] The air-guiding means 10 contains in the embodiment of the
atomizer burner shown in FIG. 1 a carrier 12 which is located at a
distance to the end face 15 of the burner nozzle assembly 3, which
is formed for example as a round disk, and which together with the
end face 15 of the burner nozzle assembly 3 forms an annular gap
14. On the carrier 12 there are swirl blades 17 which are pointed
against the end face 15 of the burner nozzle assembly 3 and adjoin
it in the installation position. The swirl blades 17 are arranged
offset on the carrier with respect to a radial line through the
center point of the carrier 12 formed by the fuel feed 11 in order
to produce a tangential flow component. Two swirl blades 17 at a
time together with the carrier 12 and the burner nozzle assembly 3
form a conical channel 19 (see FIG. 2). Upon inflow into the
atomizer nozzle 2 a swirl is impressed on the combustion air flow
flowing through the annular gap 14 by the swirl blades 17 and the
conical channels 19.
[0025] The heat shield 9 or the combustion chamber 8 in the
embodiment shown in FIG. 1 on its bottom has secondary air holes 16
which can be distributed over the annular edge area of the bottom
of the heat shield 9. FIG. 1 shows by way of example only two of
these secondary air holes 16. In addition, in the side or
peripheral wall of the heat shield 9 there can be secondary air
holes. The heat shield 9 of the combustion chamber 8 is securely
attached as a separate component via a seal 18 and a flange 20 to
the burner nozzle assembly 3 for example by means of screws 23. The
flange 20 contains another air-guiding means 21 for swirling the
secondary air which is flowing into the combustion space 8 through
the secondary air holes 16. The air-guiding means 21 likewise
contains in an annular gap 22 swirl blades 25 which are arranged
roughly radially and which cause a tangential flow component for
generating swirls in the manner already described.
[0026] The atomizer burner furthermore contains within the
combustion chamber 8 in the atomization direction of the fuel in
the flame zone a damming body which is preferably a baffle plate 24
which can be made preferably conical, convex or concave. The baffle
plate 24 in this embodiment is made pot-shaped as a disk with a
collar 26 against the atomization direction of the fuel, the
diameter of the baffle plate 24 being less than that of the
combustion chamber 8, and the ratio of the diameter of the baffle
plate 24 to the diameter of the combustion chamber 8 preferably
being between 0.6 and 0.9. The baffle plate 24 is mounted on the
heat shield 9 with mounting brackets 28. The ratio of the axial
distance of the baffle plate 24 from the atomization point of the
fuel at the outlet opening 13 of the fuel feed 11 to the diameter
of the combustion chamber 8 is preferably between 0.3 and 0.6. An
ignition means 29 which is shown schematically with broken lines
for igniting the atomized fuel is located in the combustion chamber
8 following the Venturi nozzle.
[0027] A second embodiment of an atomizer burner (see FIGS. 3 and 4
in which compared to the first embodiment identical elements are
provided with identical reference numbers) contains an air-guiding
means 10' which has a pot-shaped sleeve 30, in the bottom of which
axial air holes 32 are formed, for example, axial holes, and in its
peripheral wall 33 peripheral air holes 34 are formed which are
also called tangential holes due to their alignment. The sleeve 30
is mounted on the burner nozzle assembly 3 of the atomizer nozzle
2, for example by slipping it onto the burner nozzle assembly 3 or
by some other form-fitted, force-fitted or material connections.
The axial holes 32 and the tangential holes 34 are matched to one
another such that a defined swirl is imparted to the combustion air
which flows into the air inflow channel 5 and afterwards into the
atomizer area 6.
[0028] FIG. 4 shows a sample arrangement of the axial air openings
or axial holes 32 and the peripheral air openings or tangential
holes 34 in the sleeve 30. By varying the number of openings or
holes 32, 34 and their size and arrangement the swirl of the
combustion air flow can be adjusted if necessary.
[0029] The pot-shaped sleeve 30 which is shown in FIG. 5 has in its
peripheral wall 33 air openings 35 which are bounded towards the
center of the sleeve 30 by one air guide blade at a time. A
tangential flow component is impressed on the inflowing combustion
air by the air guide blades 36.
[0030] It is apparent that combinations of the individual features
of the two embodiments for adjusting the desired air-guiding action
are possible.
[0031] Reference Number List
[0032] 2 atomizer nozzle
[0033] 3 burner nozzle assembly
[0034] 4 fuel supply
[0035] 5 air inflow channel
[0036] 6 atomizer area
[0037] 7 middle axis
[0038] 8 combustion chamber
[0039] 10 air-guiding means
[0040] 10' air-guiding means
[0041] 11 fuel feed
[0042] 12 carrier
[0043] 13 outlet opening
[0044] 14 annular gap
[0045] 15 end face
[0046] 16 secondary air hole
[0047] 17 swirl blade
[0048] 18 seal
[0049] 19 channel
[0050] 20 flange
[0051] 21 air-guiding means
[0052] 22 annular gap
[0053] 24 baffle plate
[0054] 25 swirl blade
[0055] 26 collar
[0056] 28 mounting bracket
[0057] 29 ignition means
[0058] 30 sleeve
[0059] 32 axial hole
[0060] 33 peripheral wall
[0061] 34 air opening
[0062] 35 air opening
[0063] 36 air guide blade
* * * * *