U.S. patent application number 11/993728 was filed with the patent office on 2010-06-17 for inner flame burner for regeneration of diesel particulate filter.
This patent application is currently assigned to KOREA INSTITUTE OF MACHINERY AND MATERIALS. Invention is credited to Won Seok Hong, Seong Hyun Jeong, Seong Hun Sim.
Application Number | 20100146939 11/993728 |
Document ID | / |
Family ID | 37178552 |
Filed Date | 2010-06-17 |
United States Patent
Application |
20100146939 |
Kind Code |
A1 |
Sim; Seong Hun ; et
al. |
June 17, 2010 |
INNER FLAME BURNER FOR REGENERATION OF DIESEL PARTICULATE
FILTER
Abstract
Provided is a burner for regenerating a diesel engine
particulate filter. The burner includes: a combustion chamber for
receiving exhaust gas from a diesel engine; a carburetor for
gasifying liquid fuel; a mixed gas supplying unit for mixing the
gasified fuel with an external air, and supplying the mixed gaseous
fuel to the combustion chamber; a mixed gas storing chamber
disposed in the combustion chamber for receiving the mixed gaseous
fuel and instantly storing the received mixed gaseous fuel; an
inner flame combustor made of porous material for injecting the
mixed gaseous fuel toward the inside of the inner flame combustor,
and disposed in the combustion chamber to allow an exhaust gas to
flow through the inner flame combustor; an igniter for igniting the
mixed gaseous fuel; and a flame sensor for sensing the flame on the
inner flame combustor.
Inventors: |
Sim; Seong Hun; (Daejeon,
KR) ; Jeong; Seong Hyun; (Daejeon, KR) ; Hong;
Won Seok; (Daejeon, KR) |
Correspondence
Address: |
RABIN & Berdo, PC
1101 14TH STREET, NW, SUITE 500
WASHINGTON
DC
20005
US
|
Assignee: |
KOREA INSTITUTE OF MACHINERY AND
MATERIALS
Daejeon
KR
|
Family ID: |
37178552 |
Appl. No.: |
11/993728 |
Filed: |
June 21, 2006 |
PCT Filed: |
June 21, 2006 |
PCT NO: |
PCT/KR2006/002398 |
371 Date: |
December 21, 2007 |
Current U.S.
Class: |
60/286 ; 431/287;
431/350; 60/295; 60/303 |
Current CPC
Class: |
F01N 3/0256
20130101 |
Class at
Publication: |
60/286 ; 60/303;
60/295; 431/350; 431/287 |
International
Class: |
F01N 9/00 20060101
F01N009/00; F01N 3/10 20060101 F01N003/10; F01N 3/023 20060101
F01N003/023; F23D 14/46 20060101 F23D014/46; F23Q 13/00 20060101
F23Q013/00 |
Foreign Application Data
Date |
Code |
Application Number |
Jul 22, 2005 |
KR |
10-2005-0066642 |
Claims
1. A burner for regenerating a diesel engine particulate filter,
comprising: a combustion chamber for receiving a exhaust gas from a
diesel engine through at least one of connecting pipes connected to
an exhaust gas channel of the diesel engine; a carburetor for
gasifying liquid fuel; a mixed gas supplying unit for mixing the
gasified fuel from the carburetor with an external air for burning,
and supplying the mixed gaseous fuel to the combustion chamber; a
mixed gas storing chamber disposed in the combustion chamber for
receiving the mixed gaseous fuel from the mixed gas supplying unit
and instantly storing the received mixed gaseous fuel; an inner
flame combustor made of porous material for injecting the mixed
gaseous fuel supplied from the mixed gas storing chamber in a
direction from the outside to the inside of the inner flame
combustor, and disposed in the combustion chamber to allow an
exhaust gas to flow through the inner flame combustor; an igniter
for igniting the mixed gaseous fuel injected toward the inside of
the inner flame combustor; and a flame sensor for sensing whether
the flame is made on the surface of the inner flame combustor or
not.
2. The burner of claim 1, further comprising at least one of
swirlers disposed at an inlet of the combustion chamber to swirl
the exhaust gas so as to flow the exhaust gas into the inside of
the inner flame combustor while the exhaust gas swirling.
3. The burner of claim 1, wherein the connecting pipe is disposed
in a tangential direction from the cross section of the combustion
chamber in order to flow the exhaust gas into the inner flame
combustor disposed in the combustion chamber.
4. The burner of claim 1 wherein the inner flame burner has a
cyclone shape.
5. The burner according to claim 1, further comprising a gas-flow
uniform unit disposed between the mixed gas supplying unit and the
mixed gas storing chamber in an annular shape that forms a
concentric circle with the combustion chamber for making the mixed
gas to uniformly flow into the mixed gas storing chamber in a
radial direction of the combustion chamber.
6. The burner of claim 5, further comprising a flow-rate uniform
unit for making a flow-rate of a mixed gas uniform in a length
direction of the mixed gas by sustaining the pressure distribution
of the mixed gas uniformly in the length direction of the inner
flame combustor.
7. The burner of claim 1, wherein the carburetor includes: a
gasifying chamber for gasifying a liquid fuel; an atomizer for
atomizing the liquid fuel into fine liquid drops and supplying the
atomized liquid fuel to the gasifying chamber; and a convey air
inflow line for forming a channel to flow an external air into the
gasifying chamber for conveying the gasified fuel into a mixed gas
supplying unit.
8. The burner of claim 7, wherein the convey air inflow line has a
predetermined portion disposed to pass the exhaust gas channel of
the diesel engine for heating an external air flowing along the
convey air inflow line through heat-exchanging with the exhaust gas
outputted from the diesel engine and flowing the heated air into
the gasifying chamber.
9. The burner of claim 7, wherein the mixed gas supplying unit
includes: a mixing chamber for forming a mixed gas by mixing an
external air for burning and a gasified fuel; a burning air inflow
line communicated with the mixing chamber for forming a channel for
flowing an external air for burning into the mixing chamber; a fuel
inflow line communicated with the mixing chamber and the gasifying
chamber for forming a channel for flowing a gasified fuel into the
mixing chamber; a mixed gas inflow line communicated with the
mixing chamber and the mixed gas storing chamber for forming a
channel for flowing the mixed gas from the mixing chamber into the
mixed gas storing chamber.
10. The burner of claim 9, wherein an external air inflow passage
formed in the burning air inflow line and the mixing chamber are
formed in a ventury shape that has a cross-section gradually
reduced along the flow of the external air for burning.
11. The burner of claim 9, wherein the burning air inflow line has
a predetermined portion disposed to pass the exhaust gas channel of
the diesel engine for heating an external air flowing along the
convey air inflow line through heat-exchanging with the exhaust gas
outputted from the diesel engine and flowing the heated air into
the mixing chamber.
12. The burner of claim 7, further comprising an electric control
unit for electrically feedback-controlling: a temperature and a
pressure of at least one spot in the combustion chamber; an amount
of flowing external air for conveying into the gasifying chamber, a
temperature and pressure inside the gasifying chamber; a
temperature, a pressure, and an amount of flowing an external air
for burning into the mixed gas supplying unit; an amount of flowing
a liquid fuel supplied from the fuel pump; a temperature and a
pressure of an exhaust gas after passing through a diesel
particulate filter; and operations of the combustor, the igniter,
the flame sensor and the fuel pump.
13. The burner of claim 12, wherein the gasifying unit includes: an
electric valve for controlling an amount of external air for
conveying, which is supplied through the convey air inflow line, in
response to the electric control unit; and a temperature and
pressure sensor for sensing a temperature and pressure in the
gasifying chamber and providing the sensing signal to the electric
control unit.
14. The burner of claim 12, wherein the mixed gas supplying unit
includes: an electric valve for controlling an amount of flowing an
external air for burning, which is supplied through the burning air
inflow line, in response to the electric control unit; and a
temperature and pressure sensor for sensing a temperature and
pressure of the external air for burning and providing the sensing
signal to the electric control unit.
15. The burner of claim 12, further comprising: a clean air
supplying line communicated with an outside for supplying an
external air into an ignite member of the igniter; and an electric
valve for controlling an amount of flowing the external air
supplied from the clean air supplying line in response to the
electric control unit.
16. The burner of claim 12, further comprising: a clean air
supplying line communicated with an outside for supplying an
external air to a flame sensing member of the flame sensor; and an
electric valve for controlling an amount of flowing the external
air supplied from the clean air supplying line in response to the
electric control unit.
17. The burner of claim 12, wherein the electric control unit
drives the burner when a difference of pressures detected at a
front and a rear of a diesel particulate filter is greater than a
predetermined threshold, and stops the burner when the difference
is smaller than the predetermined threshold.
18. The burner of claim 1, wherein an inner surface of the
combustion chamber is lined with at least one of ceramic wool,
creak wool or fire brick.
19. The burner of claim 1, wherein the porous material of the
combustor is one selected from the group consisting of mat type
metal fiber, ceramic and foam metal.
20. The burner of claim 19, wherein the inner flame combustor has
one selected from the group consisting of a cylinder shape, a cone
shape, a rectangle pipe shape, and combination thereof, which
include a hollow hole defining the exhaust gas channel.
21. The burner of claim 1, further comprising a heat resistant
metal mash separately disposed inside the inner flame combustor for
radiant heat-exchanging with the inside surface of the inner flame
combustor.
22. The burner of claim 1, wherein the inner flame combustor
further includes a porous supporting member for holding the shape
of the porous material by being connected to the outer surface of
the porous material.
23. The burner of claim 1, wherein the igniter is one of a spark
plug for igniting the mixed gas by generating electrical sparks,
and a grow plug for accumulating heat at the one end.
Description
TECHNICAL FIELD
[0001] The present invention relates to a diesel particulate filter
(DPF); and more particularly, to a burner for regenerating a DPF
that reduces soot by filtering soot particles included in an
exhaust gas outputted from a diesel engine.
BACKGROUND ART
[0002] Diesel engines have been generally equipped in trains,
vessels, and commercial vehicles. Also, diesel passenger vehicles
came out to the market, recently. Thus, the use of diesel engines
has increased.
[0003] As the use for diesel engines has increased, the large
amount of particulate matters (PM) such as soot and soluble organic
fraction (SOF) are produced from the diesel engines. Since such
particulate matters (PM) are major factors for environment
pollution, especially, air pollution. Therefore, the regulation of
diesel engines has become tightened.
[0004] In order to resolve the pollution problem of diesel engines,
a diesel particulate filter (DPF) was introduced. The DPF collects
soot outputted from a diesel vehicle in order to prevent soot
particles from being exhausted into the air. Also, there are many
researches in progress for developing the DPF.
[0005] FIG. 1 shows a conventional diesel particulate filter for
reducing soot produced from a diesel engine, which were introduced
in Korea Patent Publication No. 2003-0003599.
[0006] Referring to FIG. 1, the conventional diesel particulate
filter (DPF) includes a main body 10 having a monolith type ceramic
filter 11 for filtering soot particles in an exhaust gas outputted
from a diesel engine, and a burner 1 for generating the monolith
ceramic filter 11. The burner 1 includes a combustor 4 for
injecting mixed fuel supplied from a fuel injection pump 2 and an
air pump 3, and an ignition rod 5.
[0007] In the conventional DPF, soot particles included in the
exhaust gas outputted from the diesel engine are collected by the
monolith type ceramic filter 11. When the large amount of soot
particles is trapped in the ceramic filter 11, the pressure loss of
the ceramic filter 14 significantly increases. It greatly
influences the back pressure of a diesel engine. Therefore, the
soot particles collected in the filter must be removed regularly
from the filter 11 when a predetermined pressure is dropped.
Conventionally, the soot particles are removed from the filter 11
by increasing the temperature of exhaust gas to be higher than the
oxidation temperature of the soot, for example, higher than
600.degree. C., so as to oxidize (burn) the soot particles trapped
in the ceramic filter 11. In order to raise the temperature of the
exhaust gas to be higher than the oxidation temperature of the soot
particles, the flame of the burner 1 is used as a heat supplying
device. That is, a pressure sensor 6 may sense that an internal
pressure of the ceramic filter 11 increases after the large amount
of soot particles such as carbon is trapped in the filter. Then,
the pressure sensor 6 informs the controller 7 that the internal
pressure increases, and the controller 7 drives the burner I to
burn the soot particles in the filter 11. Then, the combustor 4
injects the fuel, and the ignition rod 5 ignites the fire on the
injected fuel. The combustor 4 raises the internal temperature of
the exhaust gas channel 20, while a flame holder 8 sustains the
flame made by the combustor 4. Therefore, the soot particles
collected at the ceramic filter 11 are burned and eliminated. Then,
the ceramic filter 11 can be newly used to collect the soot
particles outputted from the diesel engine.
[0008] As described above, the conventional liquid fuel injection
type burner lengthily forms the flame as shown in FIG. 1. It is
difficult to stably sustain the lengthily formed flame although the
flame holder 8 is included. Also, the stability of the flame is
greatly influenced by driving conditions of the engine. That is, it
is very difficult to stably sustain when the amount of following
the exhaust gas outputted from the engine and the pressure
conditions change abruptly. Thus, the flame uncontrollably shakes
in the exhaust gas, and is easily extinguished. These shortcomings
make the conventional DPF to become unpractical.
[0009] Especially, the amount of flowing the exhaust gas or the
pressure abruptly varies when the diesel engine accelerates or
decelerates. In this case, it is very difficult to increase or
sustain the temperature in the exhaust gas channel 20 because the
abrupt variation makes the flame instable and to be extinguished.
Accordingly, the regeneration of the filter through oxidizing the
soot particles trapped in the filter becomes difficult. That is,
the conventional burner may sustain the flame stably when the
diesel engine is regularly driven, for example, when the engine is
kept ticking over, when the engine is driven at a constant speed,
and when the engine stops. However, the conventional burner cannot
sustain the flame stably or often extinguishes the flame when the
driving conditions of the diesel engine abruptly change, for
example, when the diesel engine accelerates or decelerates. In this
case, the conventional burner cannot smoothly burn the soot
particles trapped in the filter 11. Therefore, the state of the
diesel particulate filter is getting deteriorated. Finally, the
filter 11 becomes incapable of filtering diesel particulate.
DISCLOSURE OF INVENTION
Technical Problem
[0010] It is, therefore, an object of the present invention to
provide a burner for generating a diesel particulate filter, which
is enhanced to constantly sustain a stable flame in the flow of
exhaust gas without being influenced by the abrupt variation of
driving conditions of the diesel engine.
Technical Solution
[0011] In accordance with one aspect of the present invention,
there is a burner for regenerating a diesel engine particulate
filter including: a combustion chamber for receiving a exhaust gas
from a diesel engine through at least one of connecting pipes
connected to an exhaust gas channel of the diesel engine; a
carburetor for gasifying liquid fuel; a mixed gas supplying unit
for mixing the gasified fuel from the carburetor with an external
air for burning, and supplying the mixed gaseous fuel to the
combustion chamber; a mixed gas storing chamber disposed in the
combustion chamber for receiving the mixed gaseous fuel from the
mixed gas supplying unit and instantly storing the received mixed
gaseous fuel; an inner flame combustor made of porous material for
injecting the mixed gaseous fuel supplied from the mixed gas
storing chamber in a direction from the outside to the inside of
the inner flame combustor, and disposed in the combustion chamber
to allow an exhaust gas to flow through the inner flame combustor;
an igniter for igniting the mixed gaseous fuel injected toward the
inside of the inner flame combustor; and a flame sensor for sensing
whether the flame is made on the surface of the inner flame
combustor or not.
[0012] The burner may further include at least one of swirlers
disposed at an inlet of the combustion chamber to swirl the exhaust
gas so as to flow the exhaust gas into the inside of the inner
flame combustor while the exhaust gas swirling.
[0013] The connecting pipe may be disposed in a tangential
direction from the cross section of the combustion chamber in order
to flow the exhaust gas into the inner flame combustor disposed in
the combustion chamber.
[0014] The inner flame burner may have a cyclone shape.
[0015] The burner may further include a gas-flow uniform unit
disposed between the mixed gas supplying unit and the mixed gas
storing chamber in an annular shape that forms a concentric circle
with the combustion chamber for making the mixed gas to uniformly
flow into the mixed gas storing chamber in a radial direction of
the combustion chamber.
[0016] The burner may further include a flow-rate uniform unit for
making a flow-rate of a mixed gas uniform in a length direction of
the mixed gas by sustaining the pressure distribution of the mixed
gas uniformly in the length direction of the inner flame
combustor.
[0017] The carburetor may include: a gasifying chamber for
gasifying a liquid fuel; an atomizer for atomizing the liquid fuel
into fine liquid drops and supplying the atomized liquid fuel to
the gasifying chamber; and a convey air inflow line for forming a
channel to flow an external air into the gasifying chamber for
conveying the gasified fuel into a mixed gas supplying unit.
[0018] The convey air inflow line may have a predetermined portion
disposed to pass the exhaust gas channel of the diesel engine for
heating an extern air flowing along the convey air inflow line
through heat-exchanging with the exhaust gas outputted from the
diesel engine and flowing the heated air into the gasifying
chamber.
[0019] The mixed gas supplying unit may include: a mixing chamber
for forming a mixed gas by mixing an external air for burning and a
gasified fuel; a burning air inflow line communicated with the
mixing chamber for forming a channel for flowing an external air
for burning into the mixing chamber; a fuel inflow line
communicated with the mixing chamber and the gasifying chamber for
forming a channel for flowing a gasified fuel into the mixing
chamber; a mixed gas inflow line communicated with the mixing
chamber and the combustion chamber for forming a channel for
flowing the mixed gas from the mixing chamber into the mixed gas
storing chamber.
[0020] An external air inflow passage formed in the burning air
inflow line and the mixing chamber may be formed in a ventury shape
that has a cross-section gradually reduced along the flow of the
external air for burning.
[0021] The burning air inflow line may have a predetermined portion
disposed to pass the exhaust gas channel of the diesel engine for
heating an external air flowing along the convey air inflow line
through heat-exchanging with the exhaust gas outputted from the
diesel engine and flowing the heated air into the mixing
chamber.
[0022] The burner may further include an electric control unit for
electrically feedback-controlling: a temperature and a pressure of
at least one spot in the combustion chamber; an amount of flowing
external air for conveying into the gasifying chamber, a
temperature and pressure inside the gasifying chamber; a
temperature, a pressure, and an amount of flowing an external air
for burning into the mixed gas supplying unit; an amount of flowing
a liquid fuel supplied from the fuel pump; a temperature and a
pressure of an exhaust gas after passing through a diesel
particulate filter; and operations of the combustor, the igniter,
the flame sensor and the fuel pump.
[0023] The gasifying unit may include: an electric valve for
controlling an amount of external air for conveying, which is
supplied through the convey air inflow line, in response to the
electric control unit; and a temperature and pressure sensor for
sensing a temperature and pressure in the gasifying chamber and
providing the sensing signal to the electric control unit.
[0024] The mixed gas supplying unit may include: an electric valve
for controlling an amount of flowing an external air for burning,
which is supplied through the burning air inflow line, in response
to the electric control unit; and a temperature and pressure sensor
for sensing a temperature and pressure of the external air for
burning and providing the sensing signal to the electric control
unit.
[0025] The burner may further include: a clean air supplying line
communicated with an outside for supplying an external air into an
ignite member of the igniter; and an electric valve for controlling
an amount of flowing the external air supplied from the clean air
supplying line in response to the electric control unit.
[0026] The burner may further include: a clean air supplying line
communicated with an outside for supplying an external air to a
flame sensing member of the flame sensor; and an electric valve for
controlling an amount of flowing the external air supplied from the
clean air supplying line in response to the electric control
unit.
[0027] The electric control unit may drive the burner when a
difference of pressures detected at a front and a rear of a diesel
particulate filter is greater than a pre-determined threshold, and
stops the burner when the difference is smaller than the
pre-determined threshold.
[0028] An inner surface of the combustion chamber may be lined with
at least one of ceramic wool, creak wool or fire brick.
[0029] The porous material of the combustor may be one selected
from the group consisting of mat type metal fiber, ceramic and foam
metal.
[0030] The inner flame combustor may have one selected from the
group consisting of a cylinder shape, a cone shape, a rectangle
pipe shape, and combination thereof, which include a hollow hole
defining the exhaust gas channel.
[0031] The burner may further include a heat resistant metal mash
separately disposed inside the inner flame combustor for radiant
heat-exchanging with the inside surface of the inner flame
combustor.
[0032] The inner flame combustor may further include a porous
supporting member for holding the shape of the porous material by
being connected to the outer surface of the porous material.
[0033] The igniter may be one of a spark plug for igniting the
mixed gas by generating electrical sparks, and a grow plug for
accumulating heat at the one end.
Advantageous Effects
[0034] A burner for regenerating a diesel particulate filter
according to the present invention has following advantages.
[0035] At first, the burner according to the present invention can
instantly ignite and extinguish flames because the burner includes
an inner flame combustor that is formed of porous metal fiber
having a plurality of fine flame holes. After forming the flame on
the inner flame combustor, the burner can stably sustain the flames
in the flow of exhaust gas when the exhaust gas flows into a
combustion chamber, when the engine is kept ticking over, when the
engine is driven at a constant speed. Also, the inner flame burner
according to the present invention can sustain the flame stably
while the exhaust gas outputted from the diesel engine flows into
the combustion chamber, and when the amount of flowing the exhaust
gas and the pressure thereof abruptly change due to the abrupt
variation of the load of the diesel engine.
[0036] Since the burner according to the present invention includes
the inner flame combustor having a comparatively larger surface by
forming the inner flame combustor made of porous material in a
cylinder shape, and a rectangle pipe shape, the heat can be
transferred quickly from the flames to the exhaust gas, and the
constant temperature is uniformly sustained in the combustion
chamber.
[0037] Furthermore, the burner according to the present invention
swirls the exhaust gas to move soot particles in the exhaust gas
toward the edges of the flow of the exhaust gas and forms the
flames along the edges to effectively oxidize the soot particles so
as to reduce the concentration of the soot particles in the exhaust
gas that flows into the filter. Therefore, the life time of the
filter is lengthened because the low concentrated exhaust gas flows
into the filter, and the amount of fuel wasted for forming flames
is reduced because the burning interval of the burner is also
lengthened.
[0038] In addition, the inside wall of the combustion chamber is
lined with heat resistant material such as ceramic and firebrick to
insulate and to accumulate heat at the same time, and the
insulating material can be sustained to be clean because the soot
particles on the insulating material are oxidized by the
accumulated heat.
[0039] Moreover, the burner according to the present invention
effectively regenerates a diesel particulate filter by stably
sustaining the flames. Therefore, the burner can effectively
prevent the environmental pollution caused by the exhaust gas.
[0040] Finally, the burner according to the present invention can
be used to regenerate a particulate filter in diesel engines which
are equipped in trains, vessels and vehicles. The applicability of
the burner according to the present invention is very wide as other
purposes of the burner. It is very valuable in a view of the
environmental population.
BRIEF DESCRIPTION OF THE DRAWINGS
[0041] The above and other objects and features of the present
invention will become apparent from the following description of
the preferred embodiments given in conjunction with the
accompanying drawings, in which:
[0042] FIG. 1 is a diagram a conventional diesel particulate
filter;
[0043] FIG. 2 is a diagram illustrating a diesel particulate filter
having a burner for regenerating the diesel particulate filter
according to the first embodiment of the present invention;
[0044] FIG. 3 is a diagram illustrating a diesel particulate filter
having a burner for regenerating the diesel particulate filter
according to the second embodiment of the present invention;
and
[0045] FIGS. 4 through 7 show a burner for regenerating a diesel
particulate filter according to the third embodiment of the present
invention.
BEST MODE FOR CARRYING OUT THE INVENTION
[0046] Other objects and aspects of the invention will become
apparent from the following description of the embodiments with
reference to the accompanying drawings, which is set forth
hereinafter.
[0047] FIG. 2 is a diagram illustrating a diesel particulate filter
having a burner for regenerating the diesel particulate filter
according to the first embodiment of the present invention.
[0048] Referring to FIG. 2, the burner for regenerating the diesel
particulate filter according to the first embodiment includes one
end connected to an exhaust gas channel through at least one of
connecting pipes 131 and other end connected to a particulate
filtering device such as a filter 140 for collecting soot
particles. The burner according to the first embodiment includes an
inner flame combustor 100 made of porous mat type metal fiber for
burning gasified fuel, a carburetor 120 for gasifying fuel to
supply the gasified fuel to the inner flame combustor 100, a mixed
gas supplying unit 110 for mixing the gasified fuel from the
carburetor 120 and an external air for burning and supplying the
mixed gas to the inner flame combustor 100, a combustion chamber
130 where the inner flame combustor 100 is disposed and receives an
exhaust gas from a diesel engine, and an electric control unit 160
for electrically controlling the burner.
[0049] The inner flame combustor 100 is made of porous material in
order to inject the mixed gas, which is supplied into the
combustion chamber 130, in a direction from the outside to the
inside thereof. The inner flame combustor 100 is disposed in the
combustion chamber 130 so as to flow the exhaust gas from the
connected pipe 131 into the inside thereof. The porous material of
the inner flame combustor 100 may be mat type metal fiber, foam
metal and ceramic which have high heat resistant characteristics.
Herein, the inner flame combustor 100 may further include a porous
supporting member 106 for holding the shape of the porous material
by being coupled to the outside of the porous material.
[0050] Meanwhile, a heat resistant metal mash 107 may be disposed
inside the inner flame combustor 100 to be separated from the inner
side of the inner flame combustor 100. The heat resistant metal
mash 107 may extremely raise the temperature of the exhaust gas
that flows around the heat resistant metal mash 107 through radiant
heat-exchanging with the inside of the inner flame combustor
100.
[0051] The carburetor 120 includes a gasifying chamber 121 for
gasifying a liquid fuel, an atomizer 122 for atomizing liquid fuel
such as diesel, which is pumped from a fuel tank (not shown) by a
fuel pump 128, into fine liquid drops and supplying the atomized
fuel, a heat source 123 for supplying heat for gasifying the fuel,
a temperature and pressure sensor 124 for sensing the temperature
and pressure of the atomizer 121 and supplying the sensed signal to
the electric control unit 160, a convey air inflow line 125 for
forming a passage to flow an external air to the gasifying chamber
121 in order to partially mix the gasified fuel with the air and to
convey the gasified fuel, an electric valve 126 for electrically
controlling the amount of flowing the external air, which is
supplied through the convey air inflow line 125, and a liquid drop
convey line 127 for flowing the liquid drops of atomized fuel from
the atomizer 122 to the gasifying chamber 121.
[0052] The mixed gas supplying unit 110 mixes the gasified fuel
from the carburetor 120 and the external air for burning, and
supplying the mixed air to the inner flame combustor 100. the mixed
gas supplying unit 100 includes a mixing chamber 111 for forming
the mixed gas by mixing an external air with the gasified fuel, a
burning air inflow line 112 communicated with the mixing chamber
111 for forming a passage for flowing an air into the mixing
chamber 111, a fuel inflow line 113 communicated with the mixing
chamber 111 and the gasifying chamber 121 for forming a passage to
flow the mixed gas into the mixing chamber 11, and a mixed gas
inflow line 114 communicated with the mixing chamber 111 and the
combustion chamber 130 for forming a passage to flow the mixed gas
into the combustion chamber 130. Herein, the passages for flowing
the external air for burning to the mixing chamber 111 through the
burning air inflow line 112 is formed in a ventury shape that has a
gradually reduced cross-section. By forming the passage in the
ventury shape, the mixed gas formed at the gasifying chamber 121 of
the carburetor 120 smoothly moves to the mixing chamber 111 of the
mixed gas supplying unit 110. Therefore, the mixed gas made of the
fuel and the air is smoothly supplied to the inner flame combustor
100.
[0053] A gas-flow uniform unit 133 makes the mixed gas to flow from
the mixed gas supplying unit 110 into a mixed gas storing chamber
134 uniformly in a radial direction of the combustion chamber. The
gas-flow uniform unit 133 has an annular shape that forms the
concentric circle with the inner surface of the combustion chamber
130 and is made of porous material such as honeycomb. The gas-flow
uniform unit 133 makes the mixed gas to flow uniformly into the
mixed gas storing chamber 134. Then, the mixed gas is injected
through the surface of the inner flame combustor 100 that is
disposed in the combustion chamber and made of porous material.
When the mixed gas is injected through the inner flame combustor
100, the igniter 101 ignites the mixed gas injected from the
surface of the inner flame combustor 100 to the inside thereof
through electric discharging. Then, the flames are formed on the
inner flame combustor 100 toward the inside of the inner flame
combustor 100.
[0054] The ignite performance of the igniter 101 may be degraded by
pollution such as soot particles. Therefore, a grow plug may be
used as the igniter 101. The grow plug ignites the mixed gas by
accumulating heat at the one end thereof. If a spark plug, which
ignites the mixed gas by generating the electrical sparks, is used
as the igniter 101, the igniter 101 must be sustained as clean. In
order to sustain the igniter 101 to be clean, a clean air supplying
line 104 may be further included to supply clean external air to
the igniter 101. Also, since the igniter 101 must be stopped when
the flames are formed on the inner flame combustor 100, a flame
sensor 103 is disposed. In order to sustain the flame sensor 103 or
a flame sensing member of the flame sensor 103 to be clean, a clean
air inflow line 104 may be further included for supplying fresh
air.
[0055] The combustion chamber 130, which provides a space for
receiving the exhaust gas from the diesel engine, includes a
fireproof thermal insulator 132 for thermally insulating all walls
that contact the external environment. In the combustion chamber
130, a temperature and pressure sensor 138 for sensing a
temperature and pressure in the combustion chamber 130 is disposed
and a connecting pipe 131 is connected as an exhaust gas passage.
Also, the elements of the burner such as the inner flame combustor
100, the igniter 101, the flame sensor 103 and the clean air inflow
line 104 are disposed in the combustion chamber 130.
[0056] Meanwhile, electric valves 126, 115, 105 and 129 are
disposed to control the amount of flowing an external air for
conveying, the amount of flowing an external air for burning, the
amount of flowing a clean air, and the amount of flowing the fuel
in the fuel pump. The levels of opening and closing the electric
valves 126, 115, 105 and 129 are controlled by the electric control
unit 160 through exchanging the sensing signals with the electric
control unit 160. The electric control unit 160 feedback controls
the operations of the igniter 101, the power supply 102, and the
flame sensor 103, and the sensing and control operations of the
temperature and pressure sensor 138 in the carburetor 120 in order
to normally drive the elements.
[0057] Hereinafter, the operation of the burner according to the
present invention will be described.
[0058] When a diesel engine is driven, an exhaust gas passes the
inside of the inner flame combustor 100 disposed in the combustion
chamber 130 along the connecting pipe 131 and is outputted through
a discharging pipe 150. While the exhaust gas passes, the Soot
particles and SOF included in the exhaust gas are trapped in a
diesel particulate filter 140 which is disposed between the
combustion chamber 130 and the discharging pipe 150. As the amount
of soot particles trapped in the diesel particulate filter 140
increases, the pressure loss of the diesel particulate filter 140
gradually increases. The temperature and pressure sensor 138
disposed at the front end of the diesel particulate filter 140, and
the temperature and pressure sensor 141 disposed at the rear end of
the diesel particulate filter 140 continuously transfer the
pressure and temperature signals of the particulate filter 140 to
the electric control unit 160. When the pressure difference between
the front and the rear end of the particulate filter 140 becomes
greater than a predetermined threshold value, the burner is driven
as follows in response to an operation start signal from the
electric control unit 160.
[0059] When the fuel pump 121 is driven according to the operation
start signal from the electric control unit 160, the atomizer 122
atomizes the liquid fuel and the atomized fuel flows into the
gasifying chamber 121. The gasifying chamber 121 gasifies the fuel
using the gasifying heat source 123. The gaseous fuel is mixed with
the air injected from the convey air inflow line 125. Then, the
gaseous fuel mixed with the air flows into the mixing chamber 111
in the mixed gas supplying unit 110 through the fuel inflow line
113. Herein, the external air for burning flows into the mixing
chamber 111. As a result, the mixed gas is supplied to the inner
flame combustor 100 quantitatively by storing the mixed gas in the
mixed gas storing chamber 123 through the gas-flow uniform unit
133. Then, the mixed gas is injected into the exhaust gas flowing
inside the inner flame combustor 100. Herein, the power is supplied
to the igniter 101 from the high voltage power supply 102, and the
igniter 101 ignites the mixed gas so as to form flames in a
direction from the surface of the inner flame combustor 100 toward
the inside of the combustion chamber.
[0060] After forming the flames on the inner flame combustor 100,
the flame sensor 103 transmits a flame detecting signal to the
electric control unit 160, and the igniter 101 is stopped in
response to a signal transmitted from the electric control unit
160. Then, the flames are stably sustained on the inner flame
combustor 100.
[0061] The flame formed on the inner flame combustor 100 oxidizes
the soot particles trapped in the diesel particulate filter 140 by
increasing the temperature of the exhaust gas flowing through the
combustion chamber 130 higher than the oxidization temperature of
the soot particles. That is, the diesel particulate filter 140 is
regenerated.
[0062] If the pressure difference between the front and the rear
end of the diesel particulate filter 140 returns to an original
state, the electric control unit 160 stops the fuel pump 128.
Accordingly, the carburetor 120 also stops. According to the
operations of the electric values 126, 115, 105 and 129, the inflow
of external air for conveying and burning also stops so as to
extinguish the flame on the inner flame combustor 100. As described
above, the electric control unit 160 controls the burner to ignite
the flame, to sustain the flame stably and to extinguish the flame
according to the pressure difference between the front and the read
end of the diesel particulate filter 140 that traps the soot
particles. Therefore, the regeneration of the diesel particulate
filter 140 is stably performed even if the diesel engine is
driving.
[0063] Also, the electric control unit 160 automatically controls
the amount of fuel, the amount of flowing the air for conveying and
burning to be the optimal state according to the driving condition
variation of the diesel engine. Therefore, the flames on the inner
flame combustor 100 can be stably sustained without being
extinguished although the driving condition of the diesel engine
abruptly changes.
[0064] Meanwhile, the most of conventional burners for regenerating
a diesel particulate filter are a liquid fuel injection type burner
that often unintentionally extinguishes the flames or cannot
sustain the flames stably when the load variation of the diesel
engine abruptly changes. Therefore, the most of the conventional
burners is driven only when the diesel engine is regularly driven,
for example, when the engine is kept ticking over, when the engine
is driven at a constant speed, and when the engine stops.
Therefore, the conventional burner cannot be used for regeneration
practically.
[0065] However, in the present invention, since the inner flame
combustor 100 is made of porous material having a plurality of fine
flame holes such as metal fibers, a plurality of short flames are
formed at allatonceness. Also, the heat on the inner flame
combustor 100 prevents the flames from being easily extinguished
and quickly ignites flames all over the surface of the inner flame
combustor 100. Since the flames on the inner flame combustor 100
are formed along the edges of the exhaust gas flow, the flames can
sufficiently heat the inner flame combustor 100 although the
driving condition of the diesel engine and the amount of flowing
the exhaust gas abruptly change. Moreover, since the size of flame
is very small, the variation thereof is also very small. Therefore,
the flames on the inner flame combustor 100 are stably
sustained.
[0066] When the exhaust gas flows into the inside of the inner
flame combustor 100 disposed in the combustion chamber 130 after
forming the flame on the inner flame combustor 100, the burner
according to the first embodiment can ignite, extinguish and stably
sustain the flames in the flow of exhaust gas when the exhaust gas
flows into a combustion chamber, when the engine is kept ticking
over, when the engine is driven at a constant speed. Also, the
burner according to the first embodiment can sustain the flame
stably while the exhaust gas outputted from the diesel engine flows
into the combustion chamber, and when the amount of flowing the
exhaust gas and the pressure thereof abruptly change due to the
abrupt variation of the load of the diesel engine.
[0067] While the burner according to the present invention has been
described with respect to the first embodiment, it will be apparent
to those skilled in the art that various changes and modifications
may be made. That is, the burner according to the present invention
may include various embodiments that gasifies a liquid fuel,
injects the gasified fuel through the inner flame combustor 100
which is made of porous material and disposed along the edges of
the combustion chamber where the exhaust gas flows into, and
ignites the gasified fuel to form flames on the inner flame
combustor 100 so as to transfer the heat from the edges of the
exhaust gas to the center area by the flames. Herein, the porous
material may be porous metal mat, metal fiber mat, porous ceramic,
foam metal and foam ceramic.
[0068] Also, an ultrasonic liquid fuel atomizer 122 may be disposed
between the fuel pump 128 and the gasifying chamber 121 to improve
the gasifying performance. Although the ultrasonic liquid fuel
atomizer 122 is not included, the object of the present invention
can be archived through using the liquid fuel carburetor.
Furthermore, various units that gasify liquid fuel although the
heat source is not used to gasify the liquid fuel may be used as
the carburetor in the present invention.
[0069] In the first embodiment of the present invention, the
external air flew into the gasifying chamber 121 and the mixing
chamber 111 is described as the normal temperature air. However,
the burner according to the present invention may pre-heat the
external air by guiding the external air to pass through the
exhaust gas outputted from the engine before flowing into the
gasifying chamber 121 and the mixing chamber 111. That is, the
external air may be heated by heat-exchanging with the exhaust gas
while passing the exhaust gas.
[0070] In the first embodiment of the present invention, the inner
flame combustor 100 has a cylinder shape. However, the present
invention is not limited thereby. It is obvious to those skilled in
the art that the inner flame combustor 100 may have any shapes that
allows the exhaust gas to pass through the hollow hole of the inner
flame combustor 100 to the diesel particulate filter.
[0071] Furthermore, the inner flame combustor 100 according to the
first embodiment is formed of porous metal fiber in a mat shape.
However, the inner flame combustor 100 may be formed of porous
metal, foam metal, porous ceramic or other high heat resistant
porous materials. Hereinafter, a burner for regenerating a diesel
particulate filter according to the second embodiment of the
present invention will be described with reference to FIG. 3. Since
the burner according to the second embodiment has the similar
structure compared to the burner according to the first embodiment,
the detailed descriptions of identical elements will be
omitted.
[0072] The burner according to the first embodiment has a structure
that instantly stores gasified fuel from the carburetor into the
mixed gas storing chamber 134 through the gas-flow uniform unit 133
as shown in FIG. 2. However, the burner according to the second
embodiment, as shown in FIG. 3, additionally includes a flow-rate
uniform unit 135 in the mixed gas storing chamber 134.
[0073] When the mixed gas is injected from the mixed gas storing
chamber 134 to the inside of the inner flame combustor 100, the
injecting speeds in the length direction of the inner flame
combustor 100 are generally different at spots in the length
direction of the inner flame combustor 100.
[0074] That is, the injecting speeds become varied by the influence
of the pressure distribution in the length direction of the mixed
gas storing chamber because the distance between the inner flame
combustor 100 and the side wall of the combustion chamber 130 is
constant. In the burner according to the second embodiment, the
flow-rate uniform unit 135 disposed in the mixed gas storing
chamber 134 for eliminating the influence of the pressure
distribution in the length direction.
[0075] Hereinafter, a burner for regenerating a diesel particulate
filter according to the third embodiment of the present invention
will be described with reference to FIGS. 4 through 7. Since the
burner according to the third embodiment has the similar structure
compared to the burners according to the first and the second
embodiments, the detailed descriptions of the identical elements
will be omitted.
[0076] When the exhaust gas flows from the diesel engine into the
combustion chamber, the burner according to the third embodiment
swirls the exhaust gas in order to maximize the regeneration
efficiency.
[0077] Since the flames formed on the inner flame combustor 100 are
formed along edges of the combustion chamber 130, which is the
outside of the exhaust gas flow, the flames are not influenced by
the exhaust gas flow variation. The heat is transferred from the
flames to the exhaust gas mainly through radiant heat-exchanging
with a convention current. Herein, the heat transfer mechanism
between the flames and the exhaust gas significantly influences the
level of increasing an exhaust gas temperature and the time of
increasing the exhaust gas temperature. If the flow of the exhaust
gas is swirling, the heat transfer mechanism may have superior
characteristics in the view of heat and material transfer. The
centrifugal force made by swirling moves soot particles in the
exhaust gas to the edges of the combustion chamber 130. Since the
flames are formed along the edges of the combustion chamber 130,
the soot particles in the exhaust gas are effectively oxidized.
Finally, the concentration of the soot particles in the exhaust gas
becomes reduced when the exhaust gas enters the filter 140.
Accordingly, the filter 140 collects less amount of soot particles
until the pressure difference of the filter 140 reaches at a
predetermined threshold value. Therefore, the life time of the
filter 140 becomes significantly lengthened, and the performance
thereof is also improved.
[0078] That is, the burning interval of the burner for the
identical pressure difference becomes extended so the life time of
the filter 140 is significantly lengthened. The amount of fuel used
is also significantly reduced in proportional to the lengthened
burning interval.
[0079] Swirling the exhaust gas as described above can be achieved
by modifying the configuration of the burner according to the
present invention as follows.
[0080] At first, as shown in FIG. 4, a burner for regenerating a
diesel particulate filter may be configured to have the above
mentioned advantages by disposing a swirler 136 at the inlet of the
combustion chamber 130. The swirler 136 swirls the exhaust gas flew
into the combustion chamber 130. Then, the swirling exhaust gas
flows into the combustion chamber 130. The burner may additionally
include the flow-rate uniform unit 135 for eliminating the
influence of the pressure distribution in the length direction,
which is included in the burner according to the second embodiment
as shown in FIG. 3, in the mixed gas storing chamber 134 with the
configuration that instantly stores the gasified fuel from the
carburetor 120 in the mixed gas storing chamber 134 through the
gas-flow uniform unit 133 as shown in FIG. 5.
[0081] Secondly, as shown in FIG. 6, a burner for regenerating a
diesel particulate filter may be configured to have the above
mentioned advantages by disposing the connecting pipe 137 in a
tangential direction for the cross section of the combustion
chamber 130 in order to flow the exhaust gas in the tangential
direction of the combustion chamber 130. According to this
configuration, the exhaust gas flows into the combustion chamber
130 while the exhaust gas is swirling. Preferably, the burner may
additionally include the flow-rate uniform unit 135 in the mixed
gas storing chamber 134 for eliminating the influence of the
pressure distribution in the length direction with the structure
that instantly stores the gasified fuel from the carburetor 120 in
the mixed gas storing chamber 134 through the gas-flow uniform unit
133 as shown in FIG. 2.
[0082] Thirdly, as shown in FIG. 7, a burner for regenerating a
diesel particulate filter may be configured to have the above
mentioned advantages by disposing the connecting pipe 137 in the
tangential direction from the cross section of the combustion
chamber 130 in order to flow the exhaust gas in the tangential
direction of the combustion chamber 130, and forming the inner
flame combustor 100 in a cyclone shape that maximally uses the
centrifugal force. In this case, a negative pressure is formed in
the combustion chamber, and the negative pressure attenuates the
pressure increment when the engine loads varies by the abrupt
variation of driving conditions of the diesel engine. Therefore,
the flames are further stably sustained although the engine load
changes abruptly. Furthermore, it is preferable that the burner may
additionally include the flow-rate uniform unit 135 having the
identical shape of the cyclone shape of the inner flame combustor
100 for removing the influence of the pressure distribution in the
length direction with the structures that instantly stores the
gasified fuel from the carburetor 120 in the mixed gas storing
chamber 134 through the gas-flow uniform unit 133.
[0083] While the present invention has been particularly shown and
described with reference to exemplary embodiments thereof, it will
be understood by those of ordinary skill in the art that various
changes in form and details may be made therein without departing
from the spirit and scope of the present invention as defined by
the following claims.
* * * * *