JP2000110550A - Black smoke removal device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a device to remove black smoke in exhaust gas to be discharged from a diesel engine. SOLUTION: This device is constituted by furnishing a filter to capture black smoke in exhaust gas from a diesel engine, a first nozzle capable of at least feeding fuel to exhaust gas before sending it to this filter, a catalyser combustor provided between the first nozzle and the filter and capable of burning exhaust gas and a precombustor 30 furnished with a second nozzle 18 capable of feeding fuel-air mixture to the inside of a precombustion chamber 37 before feeding fuel from the first nozzle and an igniter 19 to ignite the mixture and capable of heating and raising temperature of a part of exhaust gas to specified temperature by turning and introducing it, and the igniter is provided in the neighbourhood of a spray periphery 37 of the mixture fed from the second nozzle 18, and spark discharge electrodes 19a, 19b having a semi-circular cylindrical plate 51 which is a strip stream generation means are arranged.

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. 21 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. are 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]

According to the present invention, there is provided a black smoke removing apparatus according to the present invention for solving the above-mentioned problems.
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, and a first nozzle and a filter disposed between the first nozzle and the filter. A catalyst combustor provided to combust the exhaust gas; a second nozzle capable of supplying a mixture of fuel and air into a pre-combustion chamber before supplying fuel from the first nozzle; and igniting the mixture. And a pre-combustor capable of heating and raising the temperature to a predetermined temperature by swirling and introducing a part of the exhaust gas. The pre-combustor is supplied with the igniter from the second nozzle. The spark generation means is provided near the outer edge of the spray of the air-fuel mixture, and has a wake generation means.

According to a second aspect of the present invention, there is provided a filter for trapping black smoke in exhaust gas from a diesel engine, and 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 the filter and capable of burning the exhaust gas; and supplying a mixture of fuel and air into the pre-combustion chamber before supplying the fuel from the first nozzle. A pre-combustor, which comprises a second nozzle capable of igniting the mixture and a igniter for igniting the air-fuel mixture; Is characterized in that a spraying means is provided in which the air-fuel mixture jetted from the second nozzle has a wide jet angle in the width direction.

[0012]

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. 2A is a sectional view taken along the line AA of FIG. B) is a view in the direction of arrow B in FIG. 1, FIG. 3 is a schematic view of a spark plug tip portion, and FIG. 4 is a schematic configuration diagram of a black smoke removing device.

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. 4, 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 pre-combustor 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 is provided as a first nozzle, and the fuel / air spray nozzle 14 is connected to the fuel tank 8.
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 an igniter (spark system) 19 are provided adjacent to the spray nozzle 18. The fuel / air spray nozzle 18
The pressurized fuel sent from the fuel tank 8 via the flow control valve 15 and the pressurized fuel sent from the existing compressor 16 via the flow control valve 17 in the same manner as the fuel / air spray nozzle 14 for catalytic combustion. Incoming pressurized air can be mixed and sprayed into the exhaust gas introduced into the pre-combustor 11. The igniter 19 is energized at a predetermined time from the battery 10 via a relay 20 to generate heat, and can ignite the 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. 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. 4 denote fuel pumps for supplying fuel under pressure.

The pre-combustor 30 according to the present embodiment is shown in FIG.
The pre-combustor 11 is provided as a pre-combustor, and a igniter of the pre-combustor is used as a spark generating means, and a wake generating means is arranged in a spark portion (electrode) to improve the fuel retention and improve the fuel retention. The ignitability and combustion stability are improved.

As shown in FIG. 1, a pre-combustor 30 according to the present embodiment comprises a cylindrical inner cylinder 32 and an outer cylinder 33 each having one end (upstream of exhaust gas flow) closed by a side wall 31. The exhaust pipe 4 is formed of a double cylinder, and the downstream end of the exhaust path 4 is connected to the outer cylinder 33 in a tangential direction.
During this time, the exhaust gas is swirled (see the arrow in FIG. 2A). The inner cylinder 32 is formed of, for example, a porous body, and a part of the exhaust gas is pre-combusted on the peripheral wall in the same direction as the direction in which the exhaust gas is swirled and introduced between the inner and outer cylinders 32 and 33. Inflow holes 35 for swirling and introducing into the chamber 34 are equally arranged in the circumferential direction and are formed in multiple in the cylinder axis direction.

The fuel / air spray nozzle (second nozzle) 18 described above is attached to the center of the side wall 31 so that a mixture of light oil 18a and air 18b is supplied to the pre-combustion chamber 3.
4.

On the side wall 31 side of the inner cylinder 32, a donut plate-shaped flame holding plate 36 surrounds a fuel / air spray outer edge 37 ejected from the fuel / air spray nozzle 18 into the pre-combustion chamber 34. The pre-combustion chamber 34 stabilizes combustion.

A cylindrical wire mesh 38 is provided along the inner wall of the inner cylinder 32, so that the flame holding and heat insulating properties are enhanced, and a good combustion state is maintained.

Further, inside the pre-combustor main body 32, an appropriate number (four in the figure) of turning prevention plates 39 are circumferentially arranged between the pre-combustor main body 32 and the inner cylinder 32 so as to be uniformly turned and introduced. Exhaust gas that does not flow into the pre-combustion chamber 34 of the exhaust gas that has flowed is suppressed from flowing excessively and flows into the catalytic combustor 12 side. The stable combustion in the chamber 34 is obtained.

Further, on the rear end side of the turning prevention plate 39,
A flow adjusting plate 40 having a plurality of holes is provided to adjust the flow rates of the exhaust gas flowing into the pre-combustion chamber 34 and the exhaust gas not flowing into the pre-combustion chamber 34.

Further, in the present embodiment, a secondary air injection port 42 for discharging secondary air 41 introduced from the outside is provided around the second nozzle 18 on the side of the pre-combustion chamber 34 on the side wall 31. 18 are provided. The secondary air 41 introduced here is supplied from the outside to the air chamber 43 having a double structure composed of the inner cylinder 31a and the outer cylinder 31b on the side wall 31, and from the air chamber 43 via the secondary air outlet 42. It is jetted into the pre-combustion chamber 34. The ejected secondary air 41 is different from the primary air 18b for spraying the light oil 18a supplied to the second nozzle 18, and is different from the primary air 18b.
The fuel is supplied around the fuel spray injected from the combustion chamber 34. The ratio of the amount of oxygen around the fuel spray sprayed into the pre-combustion chamber 34 is improved to improve the combustion ignitability and the stability of combustion. I have to.

The secondary air introducing means forms an air chamber 43 with the side wall 31 being doubled, and the side wall 31 is cooled by the secondary air 41 introduced from the outside, so that the cooling function of the pre-combustor is achieved. Plays.

In this embodiment, FIGS. 1 and 3
As shown in (A) to (C), the above-mentioned fuel / air spray nozzle (second nozzle) 18 is attached to the center of the side wall 31, and the pre-combustion chamber 3 is provided from the second nozzle 18.
4, a mixture 5 of fuel 18a and air 18b ejected into
A semi-cylindrical plate 51 as a wake generating means is provided in the direction orthogonal to the axial direction in the vicinity of the spray outer edge 37 of the semi-cylindrical plate 5.
1 is provided with one end of a discharge electrode (positive electrode) 19a of a spark plug 19 as an igniter, and the other discharge electrode (negative electrode) 19b is disposed at a predetermined interval d in the axial direction. A part of the supplied air-fuel mixture becomes a wake by the semi-cylindrical plate 51 which is a wake generating plate, and the air-fuel mixture 50 entrained behind the semi-cylindrical plate 51 is a spark 52 generated between the electrodes 19a and 19b. Ignition by

That is, in the present embodiment, the semi-cylindrical plate 51
Is provided near the spray outer edge of the air-fuel mixture 50, a part of the flow of the air-fuel mixture 50 supplied from the upstream side (the left side in FIG. 3A) is separated, and A flow (Kalman vortex) is generated, and the air-fuel mixture 50 retained in the downstream
Is generated between the discharge electrodes 19a and 19b.
And the ignitability is improved. In other words,
Even a gas having a low oxygen concentration such as exhaust gas can be easily ignited.

In this embodiment, the discharge electrodes 19a,
Although the electrodes 19b are arranged in the axial direction which is the flow direction of the air-fuel mixture 50, the present invention is not limited to this, and the discharge electrodes 19a and 19b are arranged along the semi-cylindrical plate 51 so as to face each other. Thus, a spark may be generated in a direction orthogonal to the axial direction.

[Operation / Effect] In such a black smoke removing device, the exhaust gas discharged from the diesel engine 1 is fed into the filter 13 via the exhaust passage 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 of 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 igniter 19 and the mixture of fuel and air is sprayed into the exhaust gas introduced into the pre-combustor 11 from the pre-combustion fuel / air spray nozzle 18 by controlling the flow control valves 15 and 17. I do.

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 supplied to the catalyst combustor 12 by the catalyst combustion fuel / air spray nozzle 14. Heat and raise the temperature to the ignition temperature of the air-fuel mixture. 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 conditions 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 the present embodiment, since the spark plug 19 having the semi-cylindrical plate 51 serving as the wake generating means is provided, the wake is generated, so that the fuel retention can be improved. It is possible to improve the ignitability of the fuel and stabilize the combustion.

Further, in the spark system which is the igniter of the present invention, since a cooling means such as a glow plug system as another igniter is not required, the number of members is reduced and the manufacturing cost of the pre-combustor is reduced. Can be achieved.

[Second Embodiment] [Configuration] FIG. 5 is an explanatory view of the structure of a pre-combustor showing a second embodiment of the present invention, FIG. 6 is a view taken in the direction of an arrow C, and FIGS.
(C) is a schematic view of the tip of the spark plug.

This is different from the first embodiment in that the semi-cylindrical plate 51 serving as the wake generating means is replaced with the one shown in FIGS.
As shown in (C), a bowl-shaped semicircular member 53 is provided. One end of one discharge electrode 19a is attached to the center of the semicircular member 53, and a predetermined distance d is set. The other discharge electrode 19b is arranged so that the tip of the electrode faces one electrode 19a. Other configurations are the same as those in FIG. The electrodes 19a, 1
The distance d between 9b is the distance in the direction in which sparking is desired,
The electrodes 19a and 19b are set so that the distance d is the shortest distance.
Is installed.

[Operation / Effect] In this embodiment, a wake of the air-fuel mixture 50 is generated by the bowl-shaped semi-spherical member 53, and one of the discharge electrodes 19 a arranged in the semi-spherical member 53 is formed. The mixture 50 is ignited by generating a spark between the air-fuel mixture and the other discharge electrode 19b.
Otherwise, the same operation and effect as those of the first embodiment can be obtained.

[Third Embodiment] [Structure] FIG. 8 is a structural explanatory view of a pre-combustor showing a third embodiment of the present invention, FIG. 9 is a view taken in the direction of an arrow D, and FIGS.
(C) is a schematic view of the tip of the spark plug.

This is different from the first embodiment in that the semi-cylindrical plate 51, which is the wake generating means, is replaced with the one shown in FIG.
As shown in (B), the tip of one of the discharge electrodes 19c has a spherical shape, and the other spherical discharge electrode 19d is disposed so as to face a predetermined distance d. Other configurations are the same as those in FIG. The size of the sphere of the discharge electrode may not be the same, and as shown in FIG. 10C, the discharge electrode 19e on the upstream side of the air-fuel mixture is at least larger than the discharge electrode 19f on the downstream side, and What is necessary is just to make it easy to generate a flow.

[Operation / Effect] In this embodiment, a special member is not required as a means for generating a wake, unlike the first and second embodiments, the discharge electrode is simply made spherical, and The wake of the air-fuel mixture is generated only by making the size of the sphere of the side electrode the same or slightly larger than that of the wake side, and one discharge electrode 19c (or 19e) and the other discharge electrode 19d
(Or 19f) to ignite the air-fuel mixture 50 by generating a spark. Otherwise, the same operation and effect as those of the first embodiment can be obtained.

[Fourth Embodiment] [Structure] FIG. 11 is an explanatory view showing the structure of a precombustor according to a fourth embodiment of the present invention, FIG. 12 is a view taken in the direction of an arrow E, and FIG.
(C) is a schematic view of a spark plug tip.

As shown in FIGS. 13A to 13C, the spherical discharge electrode in the third embodiment is formed into a cylindrical discharge electrode 19g, and the other discharge electrode 19h is also formed into a cylindrical shape. At the same time, the projections 19i, 19i are provided at positions where the opposing shortest distance d is provided. Other configurations are the same as those in FIG. Note that the columnar diameters of the discharge electrodes need not be the same, and the diameter of the discharge electrode 19e on the upstream side of the air-fuel mixture is at least larger than the diameter of the discharge electrode 19f on the downstream side, so that the wake easily occurs. I just need.

[Operation / Effect] In this embodiment, as in the third embodiment, no special member is required as a means for generating a wake, and mixing is performed by merely forming a discharge electrode in a columnar shape. A wake of air is generated, and one discharge electrode 19
The air-fuel mixture 50 is ignited by reliably generating a spark between the convex portions 19i, 19i, which is the shortest distance d between the g and the other discharge electrode 19h. Otherwise, the same operation and effect as those of the first embodiment can be obtained.

In the above-mentioned embodiment, the spark ignitability is improved by using the spark generating means having the wake generating means. However, in the following embodiments of the present invention, the fuel spray speed is reduced to reduce A case where the ignitability is improved will be described.

[Fifth Embodiment] [Configuration] FIG. 14 is a plan view illustrating the structure of a precombustor according to a fifth embodiment of the present invention, and FIG. 15 is a side view thereof. FIG. 16 is an explanatory plan view of a precombustor of a comparative example. FIG.
FIG. 7 is a spray state diagram of the second nozzle of the present embodiment. FIG. 18 is a spray distribution diagram of the second nozzle of the present embodiment.
FIG. 19 is a spray state diagram of the second nozzle of the comparative example. FIG.
0 is a spray distribution diagram of the second nozzle of the comparative example. The configuration of the pre-combustor of this embodiment is the same as that of the above-described first embodiment shown in FIG. Also,
The electrode of the igniter 19 provided in the pre-combustor is the spherical spark discharge type electrode 19 described in the third embodiment.
c, 19d. In this embodiment, as shown in FIGS. 14 and 15, it is provided with a second nozzle (internal mixing type) 61 that spread the ejection angle alpha ₁ in the width direction as a second nozzle. Since spray 62 ejected angle alpha ₁ of the width direction is ejected from a wide second nozzle 61 has a spray rate decreases, thereby improving the ignitability. The second nozzle 61 is used as a wide width direction of the spray angle alpha _1, as shown in FIG. 17. In the present embodiment, an internal mixing (mixing of light oil and air inside the nozzle) type nozzle is used as the second nozzle 61, but the present invention is not limited to this, and the spray that spreads in the width direction is used. You may use the external mixing type | mold nozzle which can perform.

On the other hand, in the precombustor shown in FIG. 16 provided with the external mixing type second nozzle 63 having a narrow spray width W _{2 in the} width direction as shown in FIG. 19 as a comparative example, the spray speed is high. And the ignitability decreases.

That is, when the second nozzle 61 shown in FIGS. 14 and 15 having a large spread angle in the width direction of the spray is used, as shown in FIG. Has a peak at about 2 m / sec (average flow velocity: 2.3 m / sec). However, when the second nozzle 63 shown in FIG. As shown in FIG. 20, the spray speed of the particle number peaks at about 16 m / sec (average flow velocity: 15.9 m / sec).
Seconds), and the difference in speed is clear. The particle diameter distributions of the second nozzle 61 having a large spray angle α _{1 in} the width direction and the second nozzle 63 having a small spray angle β _{1 in} the width direction are substantially the same (the Sauter mean particle diameter of the second nozzle 61 is 10). (0.3 μm, arithmetic average particle diameter: 5.3 μm; Sauter average particle diameter of second nozzle 63: 13.9 μm, arithmetic average particle diameter: 7.0 μm). Therefore, the spray speed of the second nozzle 61 having a wide spray angle α ₁ in the width direction is reduced, so that the ignitability is improved.

[Operation / Effect] In the present embodiment, the provision of the second nozzle 61 having a wide ejection angle α _{1 in} the width direction reduces the spray speed, thereby improving the ignitability.

When a spark type electrode is used as the igniter, the ignitability can be surely improved by reducing the spray speed.

[0055]

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. In the pre-combustor, the igniter is provided near the outer periphery of the spray of the air-fuel mixture supplied from the second nozzle, and is a spark generating means having a wake generating means. As a result of the flow, the fuel retention can be improved, and the fuel ignitability can be improved and the combustion stability can be improved. Therefore, even when applied to diesel vehicles that frequently repeat running and stopping, such as route buses and garbage trucks, even when stopped (idling state) and during low load areas, they are not affected by operating conditions. ,
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, there is provided 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 supplied to the filter, a catalytic combustor provided between the first nozzle and the filter and capable of burning the exhaust gas; Before the fuel is supplied from one 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 swirled to introduce a part of the exhaust gas. And a pre-combustor capable of heating and raising the temperature to a predetermined temperature.
Since the spraying means is provided with a wide-angle jet angle of the air-fuel mixture ejected from the nozzle, the spray speed of the air-fuel mixture is reduced and the ignitability is improved. Therefore, even when applied to diesel vehicles that frequently repeat running and stopping such as route buses and garbage trucks, even when stopped (idling state) and during low-load areas, they are not affected by operating conditions. Thus, the filter regeneration operation can be performed stably. As a result,
It is possible to reduce the load of the exhaust gas on the atmospheric environment.

[Brief description of the drawings]

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

2A is a cross-sectional view taken along line AA of FIG. 1, and FIG. 2B is a view taken in the direction of arrow B in FIG.

FIG. 3 is a schematic view of a spark plug tip.

FIG. 4 is a structural explanatory view of the graphite removing apparatus of the present invention.

FIG. 5 is a structural explanatory view of a precombustor according to a second embodiment of the present invention.

FIG. 6 is a view taken in the direction of arrow C.

FIG. 7 is a schematic view of a tip portion of the spark plug.

FIG. 8 is a structural explanatory view of a precombustor according to a third embodiment of the present invention.

FIG. 9 is a view as seen from an arrow D.

FIG. 10 is a schematic view of a tip portion of the spark plug.

FIG. 11 is a structural explanatory view of a precombustor according to a fourth embodiment of the present invention.

FIG. 12 is a view as seen from an arrow E.

FIG. 13 is a schematic view of the spark plug tip.

FIG. 14 is an explanatory plan view of a pre-combustor according to a fifth embodiment of the present invention.

FIG. 15 is an explanatory side view of a pre-combustor according to a fifth embodiment of the present invention.

FIG. 16 is an explanatory plan view of a precombustor according to a comparative example.

FIG. 17 is a spray state diagram of a second nozzle according to the fifth embodiment of the present invention.

FIG. 18 is a spray distribution diagram of the second nozzle according to the fifth embodiment of the present invention.

FIG. 19 is a spray state diagram of a second nozzle of a comparative example.

FIG. 20 is a spray distribution diagram of the second nozzle of the comparative example.

FIG. 21 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 (first nozzle) 15 Flow control valve 16 Compressor 17 Flow control valve 18 Fuel / air spray nozzle for combustion (second nozzle) 18a Light oil 18b Air 19 Igniter 19a to 19h Electrode 20 Relay 21 Black smoke removal control unit 22a, 22b Thermocouple 30 Precombustor 31 Side wall 31a Inner wall 31b Outer wall 32 Inner cylinder 33 Outer cylinder 34 Pre-combustion chamber 35 Inlet hole 36 Flame holding plate 37 Spray outer edge 38 Wire mesh 39 Rotation prevention plate 40 Flow control plate 41 Secondary air 42 Secondary air ejection port 43 Air chamber 50 Mixture 51 Semi-cylindrical plate 52 Spark 53 Half sphere member 61, 63 second nozzle 62 spraying alpha _1, alpha _{2, β 1, β 2} spray angle

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Sadanori Toyama 3000 Tana, Sagamihara-shi, Kanagawa Prefecture Mitsubishi Heavy Industries, Ltd. Sagamihara Works (72) Inventor Yukihiro Abe 3000, Tana, Sagamihara-shi, Kanagawa Mitsubishi Heavy Industries, Ltd. In Sagamihara Works (72) Inventor Kenichi Isono 3000 Tana, Sagamihara City, Kanagawa Prefecture F-term in Sagamihara Works, Mitsubishi Heavy Industries, Ltd.F-term (reference) BA19 CA02 EA01 EA17 FA12 FA13 FA16 FB02 FC02 FC07 GB06W HA15 HA36 HA42 HA45

Claims (2)

[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 to a predetermined temperature by swirling and introducing a part of the exhaust gas, wherein the igniter includes the igniter. A black smoke removing device provided near a spray outer edge of a mixture supplied from a second nozzle and having a wake generating unit. 2. 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; 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. The pre-combustor includes the second nozzle Black smoke removing device provided with a spraying means having a wide jet angle in the width direction of the air-fuel mixture jetted from the nozzle.