JP2966840B1 - Black smoke removal device - Google Patents

Abstract

A device for removing black smoke in exhaust gas discharged from a diesel engine is provided. SOLUTION: A filter for trapping black smoke in exhaust gas from a diesel engine, a first nozzle capable of supplying at least fuel to the exhaust gas before being sent to the filter, the first nozzle and the filter And a second combustor 18 that can supply a mixture of fuel and air into the pre-combustion chamber 37 before supplying fuel from the first nozzle. And an igniter 19 for igniting the air-fuel mixture, a pre-combustor 1 capable of heating and raising the temperature to a predetermined temperature by swirling and introducing a part of the exhaust gas.
The pre-combustor 11 includes a second nozzle 1
8 is formed with a groove 47 of a surrounding member surrounding the vicinity of the outlet.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a device for removing black smoke from exhaust gas discharged from a diesel engine, and more particularly, to a diesel engine such as a route bus or a garbage truck that repeatedly travels and stops. It is effective when applied to cars.

[0002]

2. Description of the Related Art In recent years, it has been confirmed that fine particles (DEP) contained in black smoke generated by incomplete combustion of a diesel engine have a bad influence on human health. Various exhaust purifying devices “diesel particulate filter (DPF) devices” (hereinafter referred to as black smoke removing devices) for reducing exhaust particulates have been developed.

FIG. 14 shows a schematic configuration of a conventional black smoke removing apparatus. As shown in FIG.
Is connected to one end of an exhaust passage 111 for exhausting the exhaust gas 100. Near the other end of the exhaust path 111, an injector 116 for injecting the fuel 101 such as light oil into the exhaust path 111 is attached. The other end of the exhaust path 111 has a mixer 1 for mixing the exhaust gas 100 and the fuel 101.
Seventeen inlet sides are connected. At the outlet side of the mixer 117, a catalytic combustor 118 capable of burning the exhaust gas 100 is provided.
Are connected at the entrance side. An outlet side of the catalytic combustor 118 is connected to an inlet side of a honeycomb-shaped ceramic filter 119 that captures black smoke from the exhaust gas 100.

[0004] The diesel engine 110 is provided with various sensors (not shown) for detecting the number of revolutions of the engine 110, the exhaust gas temperature, and the like. On the other hand, on the outlet side of the catalytic combustor 118, various sensors (not shown) for detecting the pressure, temperature, and the like of the exhaust gas at the relevant site are provided. The detection signals of these various sensors are input to the control device 120. The control device 120 controls the driving of the injector 116 according to the input signal.

In such a black smoke removing apparatus, when the exhaust gas 100 discharged from the diesel engine 110 is fed into the filter 119 via the exhaust path 111, the mixer 117, and the catalytic combustor 118, the filter 119 Captures black smoke from the exhaust gas 100, so that the filter 11
Purified gas 103 from which the black smoke has been removed is discharged from the outlet side of No. 9.

[0006] As the black smoke in the exhaust gas 100 is captured by the filter 119 in this way, the filter 119 is gradually clogged and the engine output is reduced due to an increase in pressure loss. Eventually, the engine cannot operate. Therefore, the control device 120 controls the injector 116 based on the detection signals from the various sensors, and when the injector 116 appropriately injects a predetermined amount of the fuel 101 into the exhaust path 111, the fuel 101 and the exhaust gas 100 are mixed in a mixer 117 and burned in a catalytic combustor 118.
Accordingly, when the exhaust gas 100 passes through the filter 119, the exhaust gas 100 heats and burns the black smoke captured by the filter 119, and removes the black smoke from the filter 119 to prevent clogging. doing.

[0007]

However, when the above-mentioned black smoke removing device is applied to a diesel engine vehicle which repeatedly travels and stops frequently, such as a route bus or a garbage truck, when the vehicle is stopped (idling state). And the temperature of the exhaust gas 100 when the engine load is low, etc.
Since the ignition temperature of the first catalytic combustor 118 does not reach, the regeneration operation of the filter 119 is performed during running (during engine
High load area). For this reason,
Vehicle operation was hindered. Further, depending on the operating condition of the vehicle, the amount of black smoke to be burned at one time is large, the amount of heat generated in the filter 119 is increased, the temperature of the filter 119 becomes extremely high, and the filter 119 is damaged. There was a problem.

For this reason, when the black smoke removing device is applied to a diesel engine vehicle which repeatedly travels and stops frequently, such as a route bus or a garbage truck, the device can be used when the vehicle is stopped (idling state) and when the engine is under a low load. Exhaust gas is treated efficiently to burn graphite reliably and stably.
It is desired that a black smoke removing device capable of reducing the load of the exhaust gas on the atmospheric environment be quickly introduced.

In view of the above, the present invention provides a method of effectively and stably burning black smoke trapped in a filter even when the temperature of exhaust gas of a diesel engine is low. It is an object of the present invention to provide a black smoke removing device capable of performing the above-mentioned.

[0010]

SUMMARY OF THE INVENTION In order to solve the above-mentioned problems, a black smoke removing device according to the present invention comprises a filter for trapping black smoke in exhaust gas from a diesel engine, and a filter for supplying black smoke to the filter. A first nozzle capable of supplying at least fuel to the exhaust gas, a catalytic combustor provided between the first nozzle and the filter, capable of burning the exhaust gas, and supplying fuel from the first nozzle Before that, a second nozzle capable of supplying a mixture of fuel and air into the pre-combustion chamber and an igniter for igniting the mixture are provided, and a part of the exhaust gas is swirled and heated to a predetermined temperature. A pre-combustor capable of warming, the pre-combustor includes a pulsation prevention device for preventing pulsation of the swirl-introduced exhaust gas, and pre-combustion of the exhaust gas passing through the pulsation prevention device. The second nozzle in the room And introducing the ambient.

The invention of claim 2 is characterized in that, in claim 1, a flow path for guiding a seal gas around the second nozzle is formed.

According to a third aspect of the present invention, in the first or second aspect, the pre-combustor includes a flame-shorting plate that blocks a flame in the pre-combustion chamber at a front end side, and swirl-introduced exhaust gas. And a pulsation prevention device for preventing pulsation of the exhaust gas, and exhaust gas passing through the pulsation prevention device is introduced from around the second nozzle in the pre-combustion chamber.

[0013]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, a black smoke removing device according to the present invention will be described in detail with reference to the drawings using embodiments, but the present invention is not limited thereto.

[First Embodiment] [Configuration] FIG. 1 is a schematic view of a pre-combustor according to a first embodiment of the present invention, FIG. 2 is a sectional view taken along the line AA, and FIG.
FIG. 4 is a sectional view taken along line B-C, FIG. 4 is a sectional view taken along line CC, and FIG.

First, an outline of the configuration of a black smoke removing device in which a pre-combustor according to the present embodiment is installed will be described with reference to FIG.

As shown in FIG. 5, the diesel engine 1
An intake path 3 for sucking fresh air and an exhaust path 4 for discharging exhaust gas are respectively connected to the combustion chamber 2 through valves (not shown), and an injector 5 and a glow as an igniter. A plug 6 is provided. The injector 5 is controlled by the fuel injection control unit 7 to inject pressurized fuel (light oil) from the fuel tank 8 into the combustion chamber 2 at a predetermined injection timing and injection amount, and the glow plug 6 is controlled for starting. When the engine is started, the unit 9 controls the power supply from the battery 10 to generate heat.

The downstream end of the exhaust passage 4 is connected to the inlet side of a precombustor 11 described later. At the outlet side of the pre-combustor 11, a catalytic combustor 12 using platinum or the like capable of burning exhaust gas and a honeycomb-shaped ceramic (or non-woven fabric) filter 13 for capturing black smoke from the exhaust gas are provided. Are sequentially connected. These pre-combustors 11,
The catalytic combustor 12 and the filter 13 are integrally formed in a cylindrical shape.

Immediately before the catalytic combustor 12, a fuel / air spray nozzle 14 for catalytic combustion as a first nozzle is provided.
And pressurized air sent from the existing compressor 16 through the flow control valve 17 and mixed into the exhaust gas that has passed through the pre-combustor 11. It can be sprayed.

On the inlet side of the pre-combustor 11, a pre-combustion fuel / air spray nozzle 18 as a second nozzle and a glow plug 19 as an igniter are provided adjacent to the spray nozzle 18. The fuel / air spray nozzle 1
Reference numeral 8 denotes a pressurized fuel sent from the fuel tank 8 via the flow control valve 15 and a feed from the existing compressor 16 via the flow control valve 17, similarly to the fuel / air spray nozzle 14 for catalytic combustion. The pressurized air is mixed and sprayed into the exhaust gas introduced into the pre-combustor 11. The glow plug 19 is energized at a predetermined time from the battery 10 via a relay 20 to generate heat, and can ignite an air-fuel mixture sprayed from the fuel / air spray nozzle 18.

The flow control valves 15 and 17 and the relay 20 are driven and controlled by a signal from a control unit 21 for removing black smoke, and the control unit 21 is provided with an exhaust Detection signals from a thermocouple 22a for detecting gas temperature and a thermocouple 22b interposed in the pre-combustor 11 and detecting the temperature of exhaust gas after pre-combustion are input. The control unit 21 receives detection signals from various sensors (not shown) that detect the rotation speed of the diesel engine 1 and the like, and various signals (not shown) that detect the pressure and temperature of the exhaust gas from the catalytic combustor 12. A detection signal is input as appropriate. still,
Reference numerals 23a and 23b in FIG. 5 denote fuel pumps for supplying fuel under pressure.

The pre-combustor 31 according to this embodiment is shown in FIG.
The pre-combustor 11 is provided to stably perform combustion in a pre-combustion chamber of the pre-combustor. As shown in FIG. 1, one end (upstream of the exhaust gas flow) of the pre-combustor 11 according to the present embodiment
A pulsation prevention damper chamber (hereinafter referred to as a “damper chamber”) formed of a double cylinder having a space inside including a damper inner cylinder 33 and a damper outer cylinder 34 inside a cylindrical pre-combustor main body 32 closed by 1. ) Is disposed, and the downstream end of the exhaust passage 4 is tangentially connected to the pre-combustor main body 32, and exhaust gas is swirled between the pre-combustor main body 32 and the damper outer cylinder 35. (See arrow in the figure). As shown in FIG. 2, an inlet pipe 36 for swirling and introducing a part of the exhaust gas in the same direction as the direction in which the exhaust gas is swirled into the damper chamber 35 is provided on the peripheral wall of the damper outer cylinder 34. They are arranged equally in the circumferential direction and are multiplexed in the cylinder axis direction. Also, on the peripheral wall of the damper inner cylinder 33, FIG.
As shown in (1), introduction pipes 38 for introducing the exhaust gas into the pre-combustion chamber 37 are equally arranged in the circumferential direction and are formed in multiple in the cylinder axis direction.

At the center of the side wall 31 of the pre-combustor main body 32, the above-mentioned fuel / air spray nozzle 18 is attached.
The above-described glow plug 19 is attached to the upper portion of the side wall 31 obliquely downward so that the heat generating portion at the tip thereof straddles the outer edge of the fuel / air spray injected into the inside. A donut plate-shaped flame holding plate 39 is provided on the side wall 31 side of the introduction pipe 38 of the damper inner cylinder 34, and a fuel / air spray outer edge 40 ejected from the fuel / air spray nozzle 18 into the pre-combustion chamber 37. It is attached so as to surround it, and generates a donut plate-shaped flame to stabilize combustion in the pre-combustion chamber 37. Further, a cylindrical wire net 41 is provided along the inner wall of the damper inner cylinder 33 so as to enhance the flame holding and heat retaining properties and maintain a good combustion state.

Also, inside the pre-combustor main body 32, a suitable number (four in the figure) of rotation preventing plates 42 are circumferentially arranged between the pre-combustor main body 32 and the damper outer cylinder 34 to uniformly introduce the rotation. Excessive exhaust gas that does not flow into the damper chamber 35 is suppressed from flowing into the catalytic combustor 12 in the exhaust gas that has been exhausted, whereby negative pressure in the pre-combustion chamber 37 is suppressed, and the pre-combustion chamber 37 is suppressed. 3
7 so that stable combustion can be obtained.

Further, on the rear end side of the turning prevention plate 42,
A flow control plate 43 having a plurality of holes is provided to control the flow rates of the exhaust gas flowing into the damper chamber 35 and the exhaust gas not flowing into the damper chamber 35.

A support member 45 is provided on the downstream side of the damper chamber 35 where the rotation preventing plate 42 of the damper chamber 35 is mounted.
A flat flame reducing plate 46 for shortening the flame by interrupting the front end side of the flame by the combustion in the pre-combustion chamber 37 through the
Is installed. By providing a flame reducing plate 46 inside the pre-combustor 11, the catalytic combustor 12 shown in FIG.
It is possible to prevent ignition of fuel at the fuel / air injection nozzle 14 provided immediately before. Further, it is possible to prevent the flame from the pre-combustor 11 from coming into direct contact with the catalytic combustor 12 and prevent the catalytic combustor 12 from deteriorating.

On the side wall 31 of the damper inner cylinder 33,
Outflow pipes 71 for discharging the exhaust gas flowing into the damper chamber 35 toward the periphery of the second nozzle 18 in the pre-combustion chamber 37 are equally arranged in the circumferential direction.
A cylindrical guide ring 72 for introducing the exhaust gas flowing from 1 along the side wall 31 is mounted. This is because the air contained in the light oil injected from the second nozzle 18 is for spraying the light oil, and does not contain air enough to burn the light oil sufficiently. Also, exhaust gas is allowed to flow in order to eliminate oxygen deficiency. In general, the exhaust gas has an oxygen content of about 19% at a low load, and sufficiently contributes to combustion. Further, the pulsation of the supplied exhaust gas in the damper chamber 35 is reduced, so that there is no adverse effect on the combustion.

In this embodiment, the pre-combustion chamber 3
In the vicinity of the second nozzle 18 provided at the center of the side wall 31 of the nozzle 7, a conical groove 47 is formed as a surrounding member surrounding the vicinity of the outlet of the second nozzle 18, and the second nozzle 18 is formed by the groove 47. Spray of light oil and air sprayed from 18 4
The convection formed by the vortex 8 is formed into a small convection vortex 49 as shown in FIG.

This is to prevent the following problems. Generally, as shown in FIGS. 12 and 13, when convection is formed by the spray, convection is generated around the spray 48 by the spray 48 ejected from the second nozzle 18, and the convection is increased by a large convection vortex 50. The fine soot and the like generated by incomplete combustion ride on the large convection vortex 50 and are carried to the vicinity of the second nozzle 18, adhere to the wall surface and the vicinity of the nozzle, and hinder the spray from the second nozzle 18. Or block the ejection opening of the second nozzle. In the present embodiment, the small convection vortex 4 is formed by forming the conical groove 47.
Since only 9 is generated, soot generated inside the pre-combustion chamber 37 is prevented from being carried to the vicinity of the second nozzle. Note that the shape of the groove 47 is not limited to a conical groove, and may be a U-shaped groove or the like, or a groove having a tapered shape having a plurality of steps.

[Operation / Effect] In such a black smoke removing apparatus, the exhaust gas discharged from the diesel engine 1 is fed into the filter 13 via the exhaust path 4, the pre-combustor 11, and the catalytic combustor 12. Then, since the filter 13 captures black smoke from the exhaust gas, the exhaust gas from which the black smoke has been removed is discharged from the filter 13. In the present embodiment, the catalytic combustor 12 also purifies HC and CO in the exhaust gas.

As described above, the black smoke in the exhaust gas is filtered by the filter 1.
As 3 is captured, the black smoke captured by the filter 13 is accumulated. Then, the control unit 21 for removing black smoke controls the flow control valves 15 and 17 based on the detection signals from the various sensors to pre-combust the mixture of fuel and air from the fuel / air spray nozzle 14 for catalytic combustion. Is sprayed into the exhaust gas passing through the vessel 11.

At this time, when the vehicle is running (middle engine / high load range)
For example, if the temperature of the exhaust gas from the diesel engine 1 has reached the ignition temperature of the air-fuel mixture in the catalytic combustor 12 (about 300 ° or more), the air-fuel mixture and the exhaust gas are burned in the catalytic combustor 12. Is done. Thereby, when the exhaust gas passes through the filter 13, the exhaust gas
The black smoke trapped in the filter 3 is heated and burnt, and the black smoke is removed from the filter 13 to prevent clogging.

On the other hand, when the temperature of the exhaust gas from the diesel engine 1 has not reached the ignition temperature in the catalytic combustor 12 when the vehicle is stopped (idling state) or when the engine is in a low load range, the control for black smoke removal is performed. The unit 21 detects with the thermocouple 22a interposed in the exhaust path 4 and
Is supplied to the glow plug 19 and the mixture of fuel and air from the pre-combustion fuel / air spray nozzle 18 is introduced into the exhaust gas introduced into the pre-combustor 11 by controlling the flow control valves 15 and 17. Spray.

As a result, the air-fuel mixture sprayed from the fuel / air spray nozzle 18 is ignited and burned together with the exhaust gas, and the exhaust gas from the exhaust passage 4 is heated to the catalyst combustion start temperature.
Raise the temperature. As a result, the exhaust gas that has passed through the pre-combustor 11 is burned in the catalytic combustor 12, and when passing through the filter 13, the black smoke captured by the filter 13 is heated and burned, and Removes black smoke from garbage and prevents clogging. In other words, the filter 13
Is reproduced.

Therefore, even when the present invention is applied to a diesel vehicle such as a route bus or a garbage truck that repeatedly travels and stops frequently, it is not affected by the running condition even when the vehicle is stopped (idling state) or when the engine is under a low load. , The filter 13 can be regenerated. Further, the black smoke captured by the filter 13 can be periodically burned and removed. In addition, the amount of heat generated in the filter 13 can be suppressed to a certain value or less to prevent the filter 13 from being damaged.

In this embodiment, a conical groove 47 is formed in the vicinity of the second nozzle 18, so that the light oil / air spray 4 sprayed from the second nozzle 18 is formed.
The convection formed by the nozzle 8 can be an extremely small convection vortex 49, so that soot generated inside the pre-combustion chamber 37 is prevented from being carried to the vicinity of the second nozzle 18.

Further, a damper chamber 35 is provided in the pre-combustor 11, and exhaust gas is swirled between the pre-combustor body 32 and the damper outer cylinder 34, and an inflow pipe 36 and an introduction pipe provided in the damper chamber are provided. 38, the pulsation of the exhaust gas is attenuated, and the rectified exhaust gas is swirled into the pre-combustion chamber 37 in the damper inner cylinder 33. The influence on the state is prevented, and the ignitability and the combustibility are improved.

On the upstream side of the damper inner cylinder 33, the exhaust gas flowing into the damper chamber 35 is supplied to the second combustion chamber 37 in the pre-combustion chamber 37.
Outflow pipe 71 for flowing out around nozzle 18
Are uniformly arranged in the circumferential direction, so that the shortage of fuel air from the second nozzle 18 is eliminated, thereby improving the ignitability and the combustibility.

In the present embodiment, the damper chamber 3
5, the exhaust gas outlet 35a is provided on the catalyst combustor 12 side, so that convective gas can be discharged in the damper chamber 35, and the exhaust gas allows the damper inner cylinder 33 to be cooled. Has improved durability.

In the pre-combustion chamber 37, a flat flame shortening plate 46 for shortening the flame by interrupting the flame caused by the combustion is provided.
Is attached, it is possible to prevent ignition of fuel at the fuel / air injection nozzle 14 provided immediately before the catalytic combustor 12. Further, it is possible to prevent the flame from the pre-combustor 11 from coming into direct contact with the catalytic combustor 12,
The deterioration of the catalytic combustor 12 can be prevented.

[Second Embodiment] [Structure] FIG. 6 is an explanatory view of a main part structure of a precombustor according to a second embodiment of the present invention.

In this embodiment, a donut-shaped plate 51 is provided in the groove 47 in the first embodiment, and an air introduction pipe 52 is provided in a space in the donut-shaped 51 (FIGS. 6A, 6B and 6 B).
(C), so as to prevent the soot from entering the space inside the donut-shaped plate 51 by introducing a small amount of air as a seal gas that does not affect the spraying of the second nozzle 18. ing. Other configurations are the same as those in FIG.

[Operation / Effect] In this embodiment as well, the donut-shaped plate 51 prevents the convection vortex from entering and maintains the good combustion by always actively cleaning the inside with air. And the first
The same operation and effect as in the embodiment can be obtained.

[Third Embodiment] [Structure] FIG. 7 is an explanatory view of a main part structure of a precombustor according to a third embodiment of the present invention.

In this case, instead of the donut-shaped plate 51 in the second embodiment, a tube 53 having a bottomless frustoconical flange 53a is provided so as to surround the vicinity of the second nozzle (FIG. 7). (See (A), (B) and (C)), the air introduction pipe 52
The air introduced from the second nozzle 18 is introduced to the vicinity of the second nozzle 18. Other configurations are the same as those in FIG.

[Operation / Effect] Also in this embodiment, the air introduced by the cylinder 53 is supplied to the second nozzle 18.
, The soot is positively prevented from adhering to the vicinity of the second nozzle 18 and the nozzle portion is cleaned, so that good combustion can be maintained. The same operation and effect as in the first embodiment can be obtained.

[Fourth Embodiment] [Structure] FIG. 8 is an explanatory view of a main part structure of a precombustor according to a fourth embodiment of the present invention.

In the third embodiment, a blowing flange 54 is provided around the opening of the cylinder 53 having the bottomless truncated cone-shaped flange on the side of the second nozzle 18 (FIG. 8A). (B),
(Refer to (C)), the air introduced from the air introduction pipe 52 is introduced to the vicinity of the second nozzle 18 with further improved directivity. Other configurations are the same as those in FIG.

[Operation and Effect] Also in this embodiment, the directionality of the air introduced from the air introduction pipe 52 is further improved to positively prevent soot from adhering near the second nozzle 18, By cleaning the part, good combustion can be maintained, and the same operation and effect as in the first embodiment can be obtained.

[Fifth Embodiment] [Structure] FIG. 9 is an explanatory view showing the structure of a main part of a precombustor according to a fifth embodiment of the present invention.

This is the same as the cylinder 5 in the fourth embodiment.
A swirler 56 having a plurality of blades 55 is provided on the blow-out flange portion 3 of FIG. 3 (see FIG. 9D), and the introduced air is swirled and introduced. Other configurations are shown in FIG.
Is the same as Instead of the blades 55 of the swirler 56, as shown in FIG. 9 (E), slits 57 may be formed so as to direct the air to be introduced toward the center, and may be rectified.

[Operation / Effect] In this embodiment as well, air is swirled into the inside by the swirler 56, so that the influence on the spray is eliminated, and the second effect is positively obtained.
By preventing soot from adhering to the vicinity of the nozzle 18 and cleaning the nozzle portion, good combustion can be maintained, and the same operation and effect as in the first embodiment can be obtained.

[Sixth Embodiment] [Structure] FIG. 10 is an explanatory view of a main part structure of a precombustor according to a sixth embodiment of the present invention.

This is because the conical groove 4 as in the first embodiment is used.
7 without forming the second nozzle 18 on the flat side wall.
A thin cylinder 61 having an opening 61a for the spray 48 at the center is provided as a surrounding member surrounding the vicinity of the air outlet, and an air introduction pipe 62 for introducing air into the cylinder 61 is provided. Other configurations are the same as those in FIG.

[Operation / Effect] In this embodiment, the vicinity of the second nozzle is also cleaned by the introduction introduced into the cylinder 61, so that soot does not enter on the convection vortex 63 and good combustion is achieved. Can be maintained, and the same operation and effect as in the first embodiment can be obtained.

[Seventh Embodiment] [Structure] FIG. 11 is an explanatory view showing the structure of a main part of a precombustor according to a seventh embodiment of the present invention.

This corresponds to the cylinder 61 in the sixth embodiment.
The swirler 56 having the plurality of blades 55 according to the fifth embodiment is provided in the opening portion of the fifth embodiment, and the slit portions 57 are evenly formed so that air is swirled and introduced or rectified. . Other configurations are the same as those in FIG.

[Operation / Effect] In this embodiment as well, since the air is swirled into the inside by the swirler 56 and the slit portion 57 or is rectified, the air is introduced into the vicinity of the second nozzle in a directional manner. By positively preventing soot from adhering to the vicinity of the second nozzle 18 and cleaning the nozzle portion, good combustion can be maintained, and the same operation and effect as those of the first embodiment can be obtained. can get.

[0058]

According to the first aspect of the present invention, a filter for capturing black smoke in exhaust gas from a diesel engine, and at least fuel can be supplied to the exhaust gas before being sent to the filter. A first nozzle, a catalytic combustor provided between the first nozzle and the filter and capable of burning the exhaust gas, and before supplying fuel from the first nozzle,
A second nozzle capable of supplying a mixture of fuel and air into the pre-combustion chamber and an igniter for igniting the mixture are provided, and a part of the exhaust gas is swirled and heated to a predetermined temperature. A pre-combustor, wherein the pre-combustor has a second
With the surrounding member that surrounds the vicinity of the outlet of the nozzle, the convection formed by the spray of light oil and air sprayed from the second nozzle can be reduced to a small convection vortex. The soot is prevented from being carried to the vicinity of the second nozzle. Therefore, even when applied to diesel vehicles that repeat running and stopping frequently, such as route buses and garbage trucks, even at the time of stopping (idling state) and at the time of low load, etc., it is not affected by the operation situation, The regeneration operation of the filter can be performed stably. As a result, it is possible to reduce the load of the exhaust gas on the atmospheric environment.

According to the second aspect of the present invention, in the first aspect, the flow path for guiding the seal gas around the second nozzle is formed, so that the introduced seal gas positively and positively activates the seal gas. By preventing soot from adhering to the vicinity of the two nozzles and cleaning the nozzle portion, good combustion can be maintained.

According to a third aspect of the present invention, in the first or second aspect, the pre-combustor is swirl-introduced into the pre-combustor with a flame shortening plate for blocking a flame in the pre-combustion chamber at a front end side. A pulsation prevention device that prevents pulsation of exhaust gas is provided,
The exhaust gas that has passed through the pulsation prevention device is passed through a second combustion chamber in the pre-combustion chamber.
Since the gas is introduced from around the nozzle, the pulsation of the exhaust gas introduced into the pre-combustion chamber is prevented, and the ignitability is prevented from being reduced by eliminating the shortage of the fuel air from the second nozzle. Further, it is possible to prevent ignition of fuel at the fuel / air injection nozzle provided immediately before the filter. Therefore, even when applied to diesel vehicles that frequently repeat running and stopping such as route buses and garbage trucks, the filter regeneration work can be stably performed even in low load areas such as idling when stopping. It can be carried out.

[Brief description of the drawings]

FIG. 1 is a structural explanatory view of a precombustor according to a first embodiment of the present invention.

FIG. 2 is a sectional view taken along line AA of FIG.

FIG. 3 is a sectional view taken along line BB of FIG. 1;

FIG. 4 is a schematic view of a main part near a second nozzle of a pre-combustor.

FIG. 5 is a structural explanatory view of the graphite removing apparatus of the present invention.

FIG. 6 is an explanatory diagram of a main part structure of a precombustor according to a second embodiment of the present invention.

FIG. 7 is an explanatory diagram of a main part structure of a precombustor according to a third embodiment of the present invention.

FIG. 8 is an explanatory diagram of a main part structure of a precombustor according to a fourth embodiment of the present invention.

FIG. 9 is an explanatory diagram of a main part structure of a precombustor according to a fifth embodiment of the present invention.

FIG. 10 is an explanatory diagram of a main part structure of a precombustor according to a sixth embodiment of the present invention.

FIG. 11 is an explanatory diagram of a main part structure of a precombustor according to a seventh embodiment of the present invention.

FIG. 12 is a structural explanatory view of a pre-combustor of a comparative example.

FIG. 13 is an explanatory view of a main part structure.

FIG. 14 is a schematic configuration diagram of an embodiment of a conventional black smoke removing device.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Diesel engine 3 Intake path 4 Exhaust path 8 Fuel tank 10 Battery 11 Precombustor 12 Catalytic combustor 13 Filter 14 Catalyst combustion fuel / air spray nozzle 15 Flow control valve 16 Compressor 17 Flow control valve 18 Precombustion fuel / air Spray nozzle 19 Glow plug 20 Relay 21 Black smoke removal control unit 22a, 22b Thermocouple 31 Side wall 32 Precombustor main body 33 Damper inner cylinder 34 Damper outer cylinder 35 Pulsation prevention damper chamber (damper chamber) 36 Inflow pipe 37 Precombustion chamber REFERENCE SIGNS LIST 38 introduction pipe 39 flame holding plate 40 spray outer edge 41 wire netting 42 anti-rotation plate 43 flow rate adjustment plate 45 support member 46 flame retarding plate 47 conical groove 48 spraying 49 convection vortex 51 donut-shaped plate 52 air introduction tube 53 cylinder 54 blowing Wall 55 Blade 56 Swirler 57 Slit 61 Cylinder 62 Air introduction pipe 71 Outflow pipe 72 Guide ring

──────────────────────────────────────────────────続 き Continuing on the front page (72) Osamu Matsumoto, Inventor 3000 Tana, Sagamihara-shi, Kanagawa Prefecture Mitsubishi Heavy Industries, Ltd. Sagamihara Works (56) References JP-A-2-104911 (JP, A) JP-A-2-146408 (JP, A) JP-A-59-134313 (JP, A) JP-A-60-155714 (JP, A) U) Tokuji Hei 4-32925 (JP, B2) Tokuji Hei 6-6181 (JP, Y2) Tokuji Hei 6-6182 (JP, Y2) Tokuji Hei 1-337141 (JP, Y2) (58) Survey Field (Int.Cl. ⁶ , DB name) F01N 3/02 301-341

Claims (3)

(57) [Claims] 1. A filter for capturing black smoke in exhaust gas from a diesel engine, a first nozzle capable of supplying at least fuel to the exhaust gas before being sent to the filter, A catalyst combustor provided between the first nozzle and a filter that can burn the exhaust gas; and a second nozzle that can supply a mixture of fuel and air into a pre-combustion chamber before supplying fuel from the first nozzle. An igniter for igniting the air-fuel mixture; and a pre-combustor capable of heating and raising the temperature of the exhaust gas to a predetermined temperature by swirling and introducing a part of the exhaust gas. A black smoke removing device having a surrounding member surrounding the outlet. 2. The black smoke removing device according to claim 1, wherein a flow path for guiding a seal gas is formed around the second nozzle. 3. The pre-combustor according to claim 1, wherein the pre-combustor has a flame shortening plate for cutting off a front end side of a flame in the pre-combustion chamber, and a pulsation prevention for preventing pulsation of swirl-introduced exhaust gas. A black smoke removing device comprising a device and introducing exhaust gas passing through the pulsation preventing device from around a second nozzle in a pre-combustion chamber.