JPH1047037A - Particulate separating device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent an insulation member interposed at a support part for the discharge electrode of a particulate separating device and to block the occurrence of electric breakdown. SOLUTION: A flow passage for particulate containing fluid has two ends at which inlet pipes 2 are arranged and a central part at which an output pipe 3 is arranged. A rod-form discharge electrode 5 and a cylindrical scavenging electrode 8 arranged at the periphery of the discharge electrode 5, and a high voltage is applied therebetween. A support part for the discharge electrode 5 is supported by a device body in which a porcelain pipe 10 is fitted and which is formed conductively to the scavenging electrode 8. A porcelain cover 24 is arranged at the periphery of the porcelain pipe 10 and further, seal air injection means to blow air against the whole periphery of the surface of the porcelain pipe 10 is provided. The seal air injection means comprises a seal air nozzle 19 having an annular injection nozzle are formed at the periphery of the porcelain pipe 10; an air chamber 20 communicated therewith; and an air compressor connected to the air chamber 20.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a fine particle separating apparatus for separating fine particles from a fluid containing fine particles, and is effective for use in separating harmful fine particles contained in exhaust gas of an internal combustion engine. .

[0002]

2. Description of the Related Art Exhaust gas discharged from an internal combustion engine contains harmful fine particles, and as a technology for separating these fine particles, there is known a technology for charging and separating fine particles (for example, Japanese Unexamined Patent Publication No. Hei 5- 277313). this is,
A straight rod-shaped discharge electrode in the flow path of the fluid containing fine particles,
A cylindrical collecting electrode is provided around it, and a high voltage is applied between the discharge electrode and the collecting electrode to form an electrostatic field. The microparticles contained in the fluid are charged, and the microparticles are electrically adsorbed and collected.

[0003]

An end of the discharge electrode is supported by a device body fitted with an insulator tube and electrically conductive with respect to the collecting electrode. Insulation is achieved. However, when the harmful fine particles in the exhaust gas are separated by the above fine particle separator, the harmful fine particles adhere to the surface of the insulator tube, and the main component of the harmful fine particles is conductive carbon. Thus, there is a problem that sparks are reached in a short time and the separation of fine particles becomes impossible.

An object of the present invention is to prevent an insulating member interposed in a support portion of a discharge electrode of a particle separation device from being contaminated by particles, thereby preventing dielectric breakdown.

[0005]

According to the present invention, a discharge electrode is provided in a flow path of a fine particle-containing fluid having an inlet and an outlet, and a collecting electrode is provided around the discharge electrode. A high voltage is applied between the collector electrode and an electrostatic field is formed,
The fine particles contained in the fine particle-containing fluid are charged while the fine particle-containing fluid passes through the electrostatic field, and the fine particles are electrically adsorbed and collected. In a fine particle separation device supported by an insulating member interposed in a device main body that is configured to be conductive with respect to the collector electrode, a pollution prevention cover disposed so as to surround the periphery of the insulating member; Seal air injection means for blowing air over the entire surface of the insulating member, wherein the contamination prevention cover and the seal air injection means are provided on the inlet side of the flow path of the fine particle-containing fluid. .

The inlet and outlet of the flow path of the fluid containing fine particles can be constructed as follows. That is, the inlets are formed at both ends of the flow path, and the outlets are formed in the middle of the flow path. Alternatively, the inlet is formed at one end of the channel,
The outlet is formed at the other end of the flow path.

In addition, a plurality of flow paths for the fluid containing fine particles are provided,
It may have a structure having. In this case, the outlets of the plurality of flow paths can be formed as one common outlet.

In the above, the angle between the direction of air injection by the seal air injection means and the surface of the insulating member is zero.
It is desirably in the range of degrees to 30 degrees.

The pollution prevention cover is preferably formed of an insulating material, and for example, ceramics can be used. As a material of the insulating member interposed in the support portion of the discharge electrode, for example, ceramics can be used.

The fine particles are prevented from adhering to the surface of the insulating member by the contamination preventing cover disposed around the insulating member interposed in the supporting portion of the discharge electrode. Furthermore, since air is blown over the entire surface of the insulating member by the seal air injection means, the fine particles are further prevented from adhering to the surface of the insulating member.

[0011]

DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of the present invention will be described below with reference to FIG.
And FIG. FIG. 1 is a front sectional view of the fine particle separation device of the present invention. 2 shows one end of FIG. 1 in an enlarged manner, (a) is a front sectional view, and (b) is a left side view.

The particle separating apparatus 70 has an elongated and straight metal cylindrical case 1, and an inlet pipe 2 is attached to both ends of the cylindrical case 1, and an outlet pipe 3 is provided at the center.
Is attached.

The inlet pipe 2 is a straight circular pipe having a fluid inlet, and is connected to the periphery of the inlet end of the cylindrical case 1. The central axis of the inlet pipe 2 is displaced from the central axis of the cylindrical case 1, and the central axis of the inlet pipe 2 is located near the outer periphery of the cylindrical case 1. Also, inlet pipe 2
Is provided with a throttle plate 4 substantially in the tangential direction of the cylindrical case 1, and the inside of the inlet pipe 2 is configured such that the cross-sectional area decreases toward the cylindrical case 1. Therefore, the fluid flowing into the inlet pipe 2 becomes high-speed in the inlet pipe 2 and further flows into the cylindrical case 1 to form a high-speed swirling flow.

In the cylindrical case 1, a straight rod-shaped discharge electrode 5 is provided along the axis. The discharge electrode 5 has a large number of needle-shaped protrusions 7 protruding radially radially at intervals in the longitudinal direction on a straight shaft body 6.

In the cylindrical case 1, between the inlet tube 2 and the outlet tube 3, a cylindrical collecting electrode 8 is concentric with the cylindrical case 1 at a slight distance from the inner periphery of the cylindrical case 1. It is arranged and both ends are conductively fixed to the cylindrical case 1. The collecting electrode 8 is formed by forming a punched metal having a large number of holes into a cylindrical shape, and winding a wire mesh around the outer periphery of the cylindrical shape. For example, a punched metal having a large number of holes of 5 mmφ and a pitch of 8 mm can be used, and a wire mesh of, for example, 24 mesh can be used.

Therefore, as described later, a high voltage is applied between the discharge electrode 5 and the collecting electrode 8 so that the electrostatic field formed between the discharging electrode 5 and the collecting electrode 8 contains harmful fine particles. When the exhaust gas moves while turning, the harmful fine particles in the exhaust gas are charged and adsorbed and collected by the collection electrode 8, and the exhaust gas from which the fine particles have been removed flows toward the outlet pipe 3. Further, a part of the exhaust gas penetrates through the collecting electrode 8 from the discharge electrode 5 side and enters a space 9 between the collecting electrode 8 and the cylindrical case 1, and harmful fine particles in the exhaust gas are removed from the inner surface of the cylindrical case 1. The exhaust gas that has been adsorbed and collected on the outer periphery of the collecting electrode 8 and from which the fine particles have been removed thereafter penetrates through the collecting electrode 8, enters the discharge electrode 5 side, and flows toward the outlet tube 3 side.

Next, the support of the discharge electrode 5 will be described. Both ends of the discharge electrode 5 are supported at the inlet end of the cylindrical case 1 where the inlet tube 2 is arranged.

Hereinafter, one support portion (the support portion on the left side of the drawing) will be described. The discharge electrode 5 has a circular insulator tube 10 fitted around the outer periphery of an end portion of the cylindrical case 1, and protrudes outside through the open end of the cylindrical case 1. At the opening end of the cylindrical case 1, a metal seal air guide member 11 is provided.

The seal air guide member 11 comprises an inner seal air guide 12 and an outer seal air guide 13. The inner seal air guide 12 is a flanged cylindrical body and has a flange on the outer periphery of the body. The outer seal air guide 13 is also a cylindrical body with a flange, and has a flange on the outer periphery of the trunk.

The inner seal air guide 12 is provided on the insulator tube 10.
Has an inner diameter fitted to the outer periphery of the. The inner diameter of the outer seal air guide 13 is formed to be slightly larger than the outer diameter of the body of the inner seal air guide 12, and the outer seal air guide 13 is concentric with the outside of the body of the inner seal air guide 12. When arranged, an annular gap 18 is formed between the inner peripheral surface of the outer seal air guide 13 and the outer peripheral surface of the body of the inner seal air guide 12 to form a seal air nozzle 19.

The inner seal air guide 12 and the outer seal air guide 13 are arranged concentrically, and in a state where the outer peripheral ends of both flanges are in contact with each other, the opposite end faces of both flanges are provided. An air chamber 20 closed from the outside and communicating with the gap 18 is formed in an annular shape.

Therefore, the inner seal air guide 12
And the outer seal air guide 13 are arranged concentrically,
The flanges of the outer seal air guide 13 and the flanges of the outer seal air guide 13 and the opening end of the cylindrical case 1 are fixed to each other. The seal air nozzle 19 is configured.

The outer peripheral surface of the body of the inner seal air guide 12 and the inner peripheral surface of the body of the outer seal air guide 13
Since the predetermined portion near the opening end is formed in a tapered shape in which the diameter gradually decreases toward the tip, the injection direction of the seal air nozzle 19 forms an angle with the surface (axial direction) of the insulator tube 10, and its angle Is set to 30 degrees or less.

In the flange of the inner seal air guide 12, three air holes 21 communicating with the air chamber 20 are formed at equal intervals in the circumferential direction so as to penetrate in the axial direction.

The insulator tube 10 inserted and supported by the inner seal air guide 12 has a flange 10a on the outer periphery of the end, and the flange 10a is formed on the outer end surface of the flange of the inner seal air guide 12. Placed in the recess 22 that is
The insulator tube 10 is fixed to the inner seal air guide 12 by inserting the fixing ring 23 into the protruding end of the insulator tube 10 and fixing the fixing ring 23 and the flange portion of the inner seal air guide 12.

Therefore, the inner seal air guide 12
When air is sent into the air chamber 20 from a sealing compressed air source, for example, an air compressor (not shown), from the air hole 21 formed in the air hole, the air is blown from the seal air nozzle 19 to the entire surface of the insulator tube 10. Therefore, the adhesion of fine particles to the surface of the insulator tube 10 by the seal air injected from the seal air nozzle 19 is prevented.

In the inlet end of the cylindrical case 1,
A cylindrical insulator cover 24 is arranged concentrically with the insulator tube 10 so as to cover the periphery of the insulator tube 10. One end of the insulator cover 24 is fixed to the end surface of the flange portion of the outer seal air guide 13, extends inside the cylindrical case 1, and covers substantially the entire exposed surface of the insulator tube 10.

The support structure of the discharge electrode 5 at the other support portion (the support portion on the right side of the drawing) of the discharge electrode 5 has the same structure as described above.

As described above, the support portions at both ends of the discharge electrode 5 are insulated and supported by the apparatus main body composed of the cylindrical case 1 and the seal air guide member 11 with the insulator tube 10 interposed therebetween. I have.

A DC high voltage power supply 25 is connected between the discharge electrode 5 and the outer peripheral portion of the inlet side end of the cylindrical case 1 so that a DC high voltage is applied between the discharge electrode 5 and the collecting electrode 8. So that a high-voltage electrostatic field is formed between the discharge electrode 5 and the collection electrode 8. Normally, the discharge electrode 5 is used as a cathode and the collection electrode 8 is used as an anode. Since the discharge electrode 5 has a large number of protrusions 7 and the trapping electrode 8 has an uneven electric field having a cylindrical shape, a locally high voltage is generated even at a relatively low voltage, and corona discharge easily occurs.

The operation will be described below. Exhaust gas flowing into the apparatus from both inlet pipes 2 is accelerated by the throttle plate 4 in the process of passing through the inlet pipes 2 and flows into the cylindrical case 1 to form a high-speed swirling flow. A high-voltage electrostatic field is formed between the discharge electrode 5 and the collection electrode 8 in the cylindrical case 1, and the fine particles in the exhaust gas are charged and collected while the exhaust gas passes through the electrostatic field. It is adsorbed and collected on the electrode 8. Part of the exhaust gas penetrates through the collecting electrode 8 and enters the space 9 between the cylindrical case 1 and the collecting electrode 8, and the fine particles in the exhaust gas cause the fine particles in the inner surface of the cylindrical case 1 and the collecting electrode 8. It is adsorbed and collected on the outer surface, and then penetrates the collecting electrode 8 and flows into the discharge electrode 5 side.

The exhaust gas from which the fine particles have been separated as described above is discharged through the central outlet pipe 3 of the cylindrical case 1.

As described above, the exhaust gas is supplied to the fine particle separation device 7.
In the process of flowing into the inside and separating and removing the fine particles,
Exhaust gas flowing into the cylindrical case 1 from the inlet pipe 2 is prevented from contacting the insulator tube 10 by the insulator cover 24, so that particles in the exhaust gas adhere to the surface of the insulator tube 10. Blocked by

The exhaust gas turns around the outer periphery of the insulator cover 24 and flows into the flow path between the discharge electrode 5 and the collecting electrode 8, and a part of the exhaust gas flows between the insulator cover 24 and the insulator tube 10. Enter the gap. However, since air is blown from the seal air nozzle 19 over the entire surface of the insulator tube 10 as described above, the particles in the exhaust gas are prevented from adhering to the surface of the insulator tube 10 by the seal air. You.

As described above, since the fine particles (mainly carbon) in the exhaust gas are prevented from adhering to the surface of the insulator tube 10, the discharge electrode 5 and the collecting electrode 8 reach the spark. Is prevented.

FIGS. 3 and 4 show another embodiment 2 of the present invention.
Is shown. The second embodiment differs from the first embodiment in the formation of an inlet and an outlet in the flow path of the fluid containing fine particles. Also, the formation of the air chamber and the seal air nozzle is different. Other structures are the same as those of the first embodiment.

In the second embodiment, an inlet tube 2 is attached to one end of an elongated straight metal cylindrical case 1 and an outlet tube 3 is attached to the other end.

The inlet pipe 2 is the same as in the first embodiment,
This is a straight circular pipe having a fluid inlet, connected to the periphery of the inlet end of the cylindrical case 1, and has the same configuration as the inlet pipe 2 in the first embodiment. Therefore, the fluid flowing into the inlet pipe 2 becomes high-speed in the inlet pipe 2 and further flows into the cylindrical case 1 to form a high-speed swirling flow.

The outlet pipe 3 is a tapered circular pipe having a fluid discharge port, and is concentrically connected to the open end of the cylindrical case 1 opposite to the inlet pipe 2.

As in the first embodiment, a discharge electrode 5 and a collecting electrode 8 are provided between the inlet tube 2 and the outlet tube 3 in the cylindrical case 1.

The discharge electrode 5 is supported at the inlet end of the cylindrical case 1 where the inlet tube 2 is arranged.
Hereinafter, the support portion will be described.

The seal air guide member 31 according to the second embodiment is composed of one seal air guide. That is, in the second embodiment, the seal air guide member 31 is a cylindrical body with a flange, and the flange 33
have. The inner circumference of the flange portion 33 is the insulator tube 10
The inner diameter of the body 32 is formed to be slightly larger than the outer diameter of the insulator tube 10, and the insulator tube 10 is inserted through the seal air guide member 31. When arranged concentrically, an annular gap 34 is formed between the inner peripheral surface of the body 32 of the seal air guide member 31 and the outer peripheral surface of the insulator tube 10, and constitutes a seal air nozzle 35. ing.

The flange 3 of the seal air guide member 31
A concave portion 36 is formed on the inner peripheral surface of each of the three portions, and a concave portion 36 is formed between the seal air guide member 31 and the insulator tube 10 in a state where the seal air guide member 31 and the insulator tube 10 are concentrically arranged. An air chamber 37 closed from the outside and communicating with the gap 34 is formed in a ring shape.

Therefore, the insulator tube 10 is inserted through the seal air guide member 31 and is arranged concentrically, and the flange 33 and the open end of the cylindrical case 1 are fixed to each other. And a seal air nozzle 35 having an injection port formed in an annular shape around the insulator tube 10.

Since the inner peripheral surface of the body 32 of the seal air guide member 31 and the outer peripheral surface of the insulator tube 10 are parallel to each other, the injection direction of the seal air nozzle 35 is parallel to the surface (axial direction) of the insulator tube 10. It is.

The flange 3 of the seal air guide member 31
3, three air holes 38 communicating with the air chamber 37 are formed in the axial direction at equal intervals in the circumferential direction.

Therefore, if air is sent into the air chamber 37 from the air hole 38 formed in the seal air guide member 31 by a compressed air source for sealing, for example, an air compressor (not shown), the air flows from the seal air nozzle 35 to the insulator. Because it is sprayed all around the surface of the pipe 10,
Particles are prevented from adhering to the surface of the insulator tube 10 by the seal air injected from the seal air nozzle 35.

The insulator tube 10 inserted and supported by the seal air guide member 31 has a flange 10a on the outer periphery of the end.
This flange portion 10a is a flange portion 33 of the seal air guide member 31.
The fixing ring 40 is inserted into the protruding end of the insulator tube 10 and the fixing ring 40 is fixed to the flange 33 of the seal air guide member 31. Thereby, the insulator tube 10 is fixed to the seal air guide member 31.

The end of the discharge electrode 5 on the side of the outlet tube 3 is not supported and is configured as a free end.

As described above, the inlet tube 2 of the discharge electrode 5
The end on the side is the cylindrical case 1 and the seal air guide member 31
The insulator tube 10 is interposed and supported in an insulating manner in the apparatus main body constituted by the above. The end on the outlet tube 3 side is a free end.

The operation will be described below. Exhaust gas flowing into the apparatus from the inlet pipe 2 is accelerated by the throttle plate 4 in the process of passing through the inlet pipe 2 and flows into the cylindrical case 1 to form a high-speed swirling flow. A high-voltage electrostatic field is formed between the discharge electrode 5 and the collection electrode 8 in the cylindrical case 1, and the fine particles in the exhaust gas are charged and collected while the exhaust gas passes through the electrostatic field. It is adsorbed and collected on the electrode 8. Part of the exhaust gas penetrates through the collecting electrode 8 and enters the space 9 between the cylindrical case 1 and the collecting electrode 8, and the fine particles in the exhaust gas cause the fine particles in the inner surface of the cylindrical case 1 and the collecting electrode 8. It is adsorbed and collected on the outer surface, and then penetrates through the collecting electrode 8 and flows into the discharge electrode 5 side.

The exhaust gas from which the fine particles have been separated as described above is discharged through the outlet pipe 3 of the cylindrical case 1.

As in the first embodiment, a cylindrical insulator cover 24 is disposed concentrically with the insulator tube 10 at the entrance end of the cylindrical case 1 so as to cover the periphery of the insulator tube 10. . One end of the insulator cover 24 is fixed to the end face of the flange 33 of the seal air guide member 31, extends inside the cylindrical case 1, and covers the exposed surface of the insulator tube 10.

Therefore, in the process in which the exhaust gas enters the apparatus from the inlet pipe 2 and is discharged from the outlet pipe 3,
As in the first embodiment, the insulator cover 24 and the seal air blown from the seal air nozzle 35 prevent the particles in the exhaust gas from adhering to the surface of the insulator tube 10.

FIG. 5 shows still another embodiment 3 of the present invention. In the third embodiment, the flow path of the fine particle-containing fluid is 2
I have one.

In the particle separating apparatus 70 of the third embodiment, two elongated, straight metal cylindrical cases 1 are arranged in parallel, and an inlet pipe 2 is attached to one end of each cylindrical case 1. One common outlet pipe 3 is connected to the open end of the two cylindrical cases 1 opposite to the inlet pipe 2.

The inlet pipe 2 is the same as in the first embodiment,
It is a straight circular pipe having a fluid inlet, connected to the periphery of the inlet end of the cylindrical case 1, and has the same configuration as the inlet pipe 2 in the first embodiment. Therefore, the fluid flowing into the inlet pipe 2 becomes high-speed in the inlet pipe 2 and further flows into the cylindrical case 1 to form a high-speed swirling flow.

The outlet pipe 3 is a tapered circular pipe. The inlet opening of the outlet pipe 3 communicates with each of the two cylindrical cases 1, and the central axis of the outlet of the outlet pipe 3 is two cylindrical cases 1.
It is located at the center between the two.

As in the first embodiment, a discharge electrode 5 and a collecting electrode 8 are provided between the inlet tube 2 and the outlet tube 3 in the cylindrical case 1.

The discharge electrode 5 is supported at the inlet end of the cylindrical case 1 where the inlet tube 2 is arranged.
Hereinafter, the support portion will be described.

A circular insulator tube 10 is fitted around the outer periphery of the discharge electrode 5 at the end of the cylindrical case 1.
Projecting outward through the opening end. A metal seal air guide member 1 is provided at the open end of the cylindrical case 1.
1 is provided.

The seal air guide member 11 includes an inner seal air guide 12 and an outer seal air guide 13. The inner seal air guide 12 is a flanged cylindrical body and has a flange on the outer periphery of the body. The outer seal air guide 13 is also a cylindrical body with a flange, and has a flange on the outer periphery of the trunk.

The inner seal air guide 12 is provided on the insulator tube 10.
Has an inner diameter fitted to the outer periphery of the. The inner diameter of the outer seal air guide 13 is formed to be slightly larger than the outer diameter of the body of the inner seal air guide 12, and the outer seal air guide 13 is concentric with the outside of the body of the inner seal air guide 12. When arranged, an annular gap 18 is formed between the inner peripheral surface of the outer seal air guide 13 and the outer peripheral surface of the body of the inner seal air guide 12 to form a seal air nozzle 19.

The inner seal air guide 12 and the outer seal air guide 13 are arranged concentrically, and the outer peripheral end of the flange of the inner seal air guide 12 is fixed to the open end of the cylindrical case 1. By fixing the outer peripheral end of the flange portion 13 to the inner peripheral surface of the cylindrical case 1, an air chamber 20 closed from the outside and communicating with the gap 18 is formed annularly between the opposed end surfaces of both flange portions. It is configured to:

Therefore, the inner seal air guide 12
And the outer seal air guide 13 are arranged concentrically,
The outer peripheral end of the flange portion of the inner seal air guide 12 is fixed to the open end of the cylindrical case 1, and the outer seal air guide 13
The outer end of the flange portion is fixed to the inner peripheral surface of the cylindrical case 1, so that the air chamber 20 and the seal air nozzle 19 communicating with the air chamber 20 and having an injection port formed annularly around the insulator tube 10. Are configured.

The outer peripheral surface of the body of the inner seal air guide 12 and the inner peripheral surface of the body of the outer seal air guide 13
Since the predetermined portion near the opening end is formed in a tapered shape in which the diameter gradually decreases toward the tip, the injection direction of the seal air nozzle 19 forms an angle with the surface (axial direction) of the insulator tube 10, and its angle Is set to 30 degrees or less.

In the flange portion of the inner seal air guide 12, three air holes 21 communicating with the air chamber 20 are formed at equal intervals in the circumferential direction so as to penetrate in the axial direction.

Therefore, the inner seal air guide 12
When air is sent into the air chamber 20 from a sealing compressed air source, for example, an air compressor (not shown), from the air hole 21 formed in the air hole, the air is blown from the seal air nozzle 19 to the entire surface of the insulator tube 10. Therefore, the adhesion of fine particles to the surface of the insulator tube 10 by the seal air injected from the seal air nozzle 19 is prevented.

At the protruding end of the insulator tube 10 inserted and supported by the inner seal air guide 12, an insulator tube mounting clamp 4 is provided.
1 is inserted and fixed, and this is the inner seal air guide 12
The insulator tube 10 is fixed to the inner seal air guide 12 by being fixed to the outer end surface of the inner seal air guide 12.

The end of the discharge electrode 5 on the side of the outlet tube 3 is not supported and is configured as a free end.

As described above, the ends of the two flow paths on the side of the inlet tube 2 of each discharge electrode 5 are connected to the apparatus body composed of the cylindrical case 1 and the seal air guide member 11 via the insulator tube 10. The outlet pipe 3 side is a free end.

The operation will be described below. Exhaust gas flowing into the apparatus from the inlet pipe 2 is accelerated by the throttle plate 4 in the process of passing through the inlet pipe 2 and flows into the cylindrical case 1 to form a high-speed swirling flow. A high-voltage electrostatic field is formed between the discharge electrode 5 and the collection electrode 8 in the cylindrical case 1, and the fine particles in the exhaust gas are charged and collected while the exhaust gas passes through the electrostatic field. It is adsorbed and collected on the electrode 8. Part of the exhaust gas penetrates through the collecting electrode 8 and enters the space 9 between the cylindrical case 1 and the collecting electrode 8, and the fine particles in the exhaust gas cause the fine particles in the inner surface of the cylindrical case 1 and the collecting electrode 8. It is adsorbed and collected on the outer surface, and then penetrates through the collecting electrode 8 and flows into the discharge electrode 5 side.

The exhaust gas from which the fine particles have been separated as described above is discharged through the outlet pipe 3 of the cylindrical case 1.

As in the first embodiment, a cylindrical insulator cover 24 is disposed concentrically with the insulator tube 10 so as to cover the periphery of the insulator tube 10 as in the first embodiment. . One end of the insulator cover 24 is fixed to the end face of the flange portion of the outer seal air guide 13, extends into the cylindrical case 1, and covers the exposed surface of the insulator tube 10.

Therefore, in the process in which the exhaust gas enters the apparatus from the inlet pipe 2 and is discharged from the outlet pipe 3,
As in the first embodiment, the insulator cover 24 and the seal air blown from the seal air nozzle 19 prevent particles in the exhaust gas from adhering to the surface of the insulator tube 10.

Hereinafter, a durability test of the fine particle separation device will be described. (1) Configuration of Test Apparatus The configuration of the test apparatus will be described with reference to FIG. The exhaust port of the diesel engine 71 is connected to the particulate separation device 7 by a pipe 72.
0 is connected to the inlet pipe. Flow meter 73
And the smoke concentration detector 74 are connected. Also,
Piping 72 between the diesel engine 71 and the flow meter 73
Is provided with a valve 75, and a discharge pipe 76 is connected to the pipe 72 on the upstream side of the valve 75, and a valve 77 is provided in the pipe 76. A pipe 78 is connected to an outlet pipe of the particle separation device 70, and a smoke concentration detector 79, and then a ceramic filter 80 and a smoke concentration detector 81 are connected to the pipe 78. A discharge port of an air compressor 82 is connected to an air hole on the inlet side of the particle separation device 70 by a pipe 83. A DC high-voltage power supply 2 is provided between one end of the discharge electrode of the particle separation device 70 and the outer periphery of the cylindrical case.
5 is connected.

(2) Sample Particle Separation Apparatus Example 1 In the particle separation apparatus described in Embodiment 1, the angle between the injection direction of the seal air nozzle 19 and the surface (axial direction) of the insulator tube 10 is 5 degrees. . Example 2 This is the fine particle separation device described in the second embodiment.

(3) Test conditions Engine: In-line 6-cylinder direct-injection diesel engine Engine speed: 1600 rpm Exhaust gas flow rate: 8 m ³ / min Exhaust gas inlet pipe temperature: 400 ° C. Applied voltage: 25 kV Smoke concentration: Bosch2 Load: All 90% of load Test time: 500 hours Seal air flow rate: Same for each example.

(4) Test Method After the engine speed is set to 1600 rpm and the load is set to 90% load, exhaust gas is passed through the particle separation device 70. At this time, the smoke concentration of the exhaust gas flowing into the particle separation device 70 is measured by the smoke concentration detector 74, and the Bosch concentration is measured.
2. Immediately after that, 25 kV is applied to the particle separation device 70 to perform a durability test. During the test, measure the discharge current,
Further, the applied voltage, smoke concentration, and inlet pipe temperature are measured every 30 minutes.

(5) Test Results As shown in FIG. 7, in Examples 1 and 2, corona discharge was stable and no spark was generated.

In all cases, the target value was 70% or more before sparking in each case.

One hour after completion of the test, the change in weight of the fine particle separator 70 is measured, the actual amount of collected fine particles is measured, and the smoke concentration detectors 7 before and after the fine particle separator 70 are measured.
4,79, the concentration detected in SAENo. 84041
When the amount of collected fine particles was calculated with reference to FIG. 2, there was a difference between the amount of collected fine particles (calculated value) and the actual change in weight of the particle separation device, and the actual amount of change in weight was smaller than the calculated value. hand,
Underweighed. This is considered to be because some of the fine particles were burning. The ceramic filter 80
Is provided to verify that the collection amount of fine particles calculated from the concentrations detected by the smoke concentration detectors 74 and 79 substantially matches the actual collection amount. It was confirmed that the amount of fine particles collected by the calculation based on the concentrations detected by the smoke concentration detectors 79 and 81 before and after and the amount of fine particles actually collected by the ceramic filter 80 substantially matched. Was done.

[0083]

As described above, according to the present invention, it is possible to prevent the insulating member interposed in the support portion of the discharge electrode of the particle separation device from being contaminated by the particles and to prevent the dielectric breakdown. In addition, it is possible to provide a fine particle separation device having excellent durability.

[Brief description of the drawings]

FIG. 1 shows an embodiment of the present invention, and is a front sectional view of a particle separation device.

FIG. 2 is an enlarged view of one end of FIG. 1, wherein (a) is a front sectional view and (b) is a left side view.

FIG. 3 shows another embodiment of the present invention, and is a front sectional view of a particle separation device.

FIG. 4 is an enlarged view of one end of FIG. 3, (a) is a front sectional view, and (b) is a left side view.

FIGS. 5A and 5B show still another embodiment of the present invention, wherein FIG. 5A is a front sectional view of a particle separation device, and FIG. 5B is a left side view thereof.

FIG. 6 is a configuration diagram showing a test device for a durability test.

FIG. 7 is a graph showing test results.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Cylindrical case, 2 ... Inlet tube, 3 ... Outlet tube, 4 ... Throttle plate, 5 ... Discharge electrode, 6 ... Shaft, 7 ... Projection, 8 ... Collection electrode, 9 ... Space part, 10 ... Insulator tube, 10a ... flange, 11 ...
Seal air guide member, 12: inner seal air guide, 13: outer seal air guide, 18: gap, 19
... Seal air nozzle, 20 ... Air chamber, 21 ... Air hole, 2
2 ... recess, 23 ... fixing ring, 24 ... insulator cover, 25
... DC high voltage power supply, 31 ... Seal air guide member, 32 ...
Body part, 33 flange, 34 gap, 35 seal air nozzle, 36 recess, 37 air chamber, 38 air hole, 39
Recess, 40: fixing ring, 41: mounting clamp, 70:
Particle separation device, 71: Diesel engine, 72: Piping, 73: Flow meter, 74: Smoke concentration detector, 75:
Valve, 76: piping, 77: valve, 78: piping, 79: smoke concentration detector, 80: ceramic filter, 81: smoke concentration detector, 82: air compressor, 83: piping.

 ──────────────────────────────────────────────────の Continued on front page (72) Inventor Akira Yamaguchi 1-9-9 Yaesu, Chuo-ku, Tokyo Imperial Piston Ring Co., Ltd.

Claims (9)

[Claims] A discharge electrode is provided in a flow path of a fluid containing fine particles having an inlet portion and an outlet portion, and a collection electrode is provided around the discharge electrode, and a high voltage is applied between the discharge electrode and the collection electrode. Is applied to form an electrostatic field, and the fine particles contained in the fine particle-containing fluid are charged in the course of the passage of the fine particle-containing fluid through the electrostatic field, and the fine particles are electrically adsorbed and collected. Wherein the discharge electrode is supported by a device main body that is configured to be conductive with respect to the collection electrode with an insulating member interposed therebetween. A pollution prevention cover disposed thereon, and sealing air injection means for blowing air over the entire surface of the insulating member, wherein the pollution prevention cover and the sealing air injection means are on the inlet side of the flow path of the fine particle-containing fluid. To Particle separation apparatus characterized by being kicked. 2. The fine particle separation apparatus according to claim 1, wherein an angle between the direction of air injection by the seal air injection means and the surface of the insulating member is in a range of 0 to 30 degrees. 3. The flow path of the fine particle-containing fluid, wherein an inlet is formed at both ends of the flow path, and an outlet is formed at an intermediate part of the flow path. 3. The fine particle separation device according to 2. 4. The flow path of the fine particle-containing fluid, wherein an inlet is formed at one end of the flow path, and an outlet is formed at the other end of the flow path. Or the fine particle separation device according to 2. 5. The fine particle separation apparatus according to claim 1, comprising a plurality of flow paths for the fine particle-containing fluid. 6. The fine particle separation apparatus according to claim 5, wherein outlets of the plurality of flow paths of the fine particle-containing fluid are formed as one common outlet. 7. The apparatus according to claim 1, wherein the contamination prevention cover is formed of an insulating material. 8. The apparatus for separating fine particles according to claim 7, wherein the material of the pollution prevention cover is a ceramic. 9. The fine particle separation device according to claim 1, wherein the insulating member interposed in the supporting portion of the discharge electrode is formed of ceramic.