JPH08144737A - Exhaust particulates filtering device - Google Patents

Abstract

PURPOSE: To effectively burn exhaust particulates by speedily and evenly heating a filter body. CONSTITUTION: A filter body A is formed by cylindrically bending a lamination body 62 prepared by laminating ceramic short fibers and irregularly tangling them, on both sides of which lamination body 62 meshes 61, 62 are superposed. One of the meshes 61, 63 is made of electroconductive material, while the other is made of non-electroconductive material.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an exhaust particulate filter for removing particulates such as carbon from the exhaust of a diesel engine.

[0002]

2. Description of the Related Art An exhaust particulate filter for collecting exhaust particulates such as carbon in the exhaust gas of a diesel engine uses a porous honeycomb molded body made of ceramics,
Known are ones using a foam-like porous body made of ceramics, one using a non-woven fabric made of an inorganic fiber, and the like.
As a method of regenerating the exhaust particulate filter, there are a method of igniting and burning the collected exhaust particulate with a flame of a burner, a method of utilizing combustion propagation, and a method of igniting and burning with electric heat.

When exhaust particulates are collected on the surface of the filter body using the ceramic molded body, the pores of the filter body become smaller and smaller, and the pressure loss due to the fluid resistance rapidly increases. When regenerated by combustion of exhaust particulates, the combustion temperature is 14
The temperature may reach 00 ° C, and the filter may be damaged or melted. On the other hand, since the filter body using the inorganic fiber burns the exhaust fine particles, it is difficult to heat the filter body quickly and uniformly.

[0004]

SUMMARY OF THE INVENTION It is an object of the present invention to provide an exhaust particle filtering device in which a filter body is heated quickly and uniformly and exhaust particles are efficiently burned.

[0005]

In order to achieve the above-mentioned object, the constitution of the present invention has a tubular shape in which a mesh-like body is superposed on both sides of a laminated body in which ceramic short fibers are laminated and entangled randomly. In an exhaust particulate filter device that is curved to form a filter body, one of the mesh bodies is made of a conductive material and the other is made of a non-conductive material.

[0006]

The filter body (filter) is formed into a tubular shape by superposing a mesh body on both sides of a laminated body in which ceramic short fibers are laminated and entangled randomly. Exhaust particles are collected as exhaust gas passes from the outer peripheral side of the filter body to the inner space of the filter body or from the inner space of the filter body to the outer side of the filter body. Exhaust particles are concentrated and deposited on the exhaust outlet surface or the back surface of the filter.

The filter body is regenerated by energizing the mesh-like body in contact with the back surface of the filter body and flowing fresh compressed air or a part of the exhaust gas through the filter body to burn the exhaust fine particles.

[0008]

1 is a side sectional view of an exhaust particulate filter according to the present invention, and FIG. 2 is a side sectional view of a filter body of the exhaust particulate filter. Exhaust particulate filter is cylindrical case 5
The cylindrical filter body A is housed inside the case 4, and the case 5
The central opening of the end plate 53 of 4 is connected to the inlet pipe 51. On the other hand, the central opening of the end plate 55 is connected to the outlet pipe 58. In order to supply fresh air to the filter body A, an air supply pipe 59 a extending from a high pressure air tank or a blower 59 is projected to the inlet pipe 51.

The filter body A is formed into a cylindrical shape by superposing mesh bodies 61 and 63 on both sides of a laminated body 62 such as a nonwoven fabric or felt formed by laminating ceramic short fibers and entangled irregularly. The left end of the filter body A is a circular end plate 60.
Closed by. On the other hand, an annular end plate 64 is joined to the right end of the filter body A. The outer peripheral edge of the end plate 64 is joined to the inner peripheral wall of the case 54.

One of the mesh bodies 61, 63 is made of a conductive material, and the other of the mesh bodies 61, 63 is made of a non-conductive material. In the illustrated embodiment, the mesh body 63 on the back surface of the laminated body 62 is a wire mesh made of a heat-resistant metal such as stainless steel, Fe—Cr—Al (iron / chromium / aluminum) alloy, and the mesh body 61 is made of SiC ( It is a woven fabric made of ceramic fibers such as silicon carbide) and alumina. The electrodes 73 and 74 are connected to both ends of the mesh body 63.

As shown in FIG. 2, the net-like bodies 61 and 63 superposed on both surfaces of the laminated body 62 are caught by a heat-resistant wire 67 penetrating the laminated body 62. As the heat-resistant wire 67, a conductive metal wire such as stainless steel or a non-conductive thread such as ceramic fiber is used. Reticulated bodies 61, 6 superposed on both front and back surfaces of the laminated body 62
By trapping 3 with each other by the metal wire 67 that penetrates the laminated body 62, the heat of the mesh bodies 61 and 63 can be quickly transferred to the laminated body 62, the reburning of the exhaust particulates can be promoted, and the regeneration time can be shortened. . As shown in FIG. 3, ring bodies 69 are inserted into both ends of the laminated body 62, while metal bands 68 are provided on the outer peripheral side.
And the electrode 73 is connected to the mesh 63.

Exhaust gas from the engine is discharged from the inlet pipe 51 through the filter A.
Supplied to That is, the exhaust particulates contained in the exhaust are collected while the exhaust passes radially inward from the outer peripheral side air space 71 of the filter body A through the laminated body 62. The exhaust from which the exhaust particles have been removed flows out from the inner space 72 to the outlet pipe 58.

When the filter body A is regenerated, the electrodes 73 and 74 at both ends of the mesh body 63 are connected to a power source (not shown) to energize the mesh body 63. Bypass exhaust to filter A,
When the blower 59 is driven, the exhaust air particles are burned while the fresh air from the air supply pipe 59a passes radially inward from the outer peripheral side air space 71 through the laminated body 62. The air in which the exhaust particulates have been burned out flows from the inner space 72 of the filter body A to the outlet pipe 58.

In the above embodiment, the mesh bodies 61, 63
Although a conductive material may be used as a conductive material, the surface area through which heat is dissipated becomes large and the power consumption increases. Therefore, it is preferable that only one side of the filter A is used as a conductive mesh. When the nets 61 and 63 on both sides of the laminate 62 are made of a conductive material, electrical insulation between the nets on both sides is necessary when only one side of the nets is energized. Transformation,
Vibration may cause a short circuit. If only the mesh on one side is made of a conductive material, the metal wire 67 can be used to capture the mesh on both sides.

In the embodiment shown in FIG. 3, the filter body A comprises mesh bodies 61 and 63, which are superposed on both surfaces of the laminated body 62, made of a non-conductive material, and the inside of the laminated body 62 is made of a conductive material. The body 65 is sandwiched. By sandwiching the net-like bodies 61 and 63 made of a conductive material inside the laminated body 62, it is possible to suppress heat dissipation during the regeneration of the filter body A and heat the laminated body 62 quickly and uniformly.

In the embodiment shown in FIG. 4, the filter body A is not a simple cylindrical shape, but the filter body A is meandered alternately inward and outward in a star-shaped or cross-sectional shape. Is something
It is possible to increase the passage area of the exhaust gas and increase the filtration capacity. The filter body A is curved in a corrugated shape by a jig in advance and then curved into a cylindrical shape, and has a plurality of portions at both ends and an intermediate portion in the axial direction,
For example, it is sandwiched between an inner holding plate 37 and an outer holding plate 35 formed of ceramics or the like and having an appropriate thickness. The inner holding plate 37 has a large number of protruding pieces 37b projecting radially outward from the annular portion 37a, and is engaged with a groove portion on the inner peripheral side of the filter body A. The outer holding plate 35 has a large number of projecting pieces 35b projecting radially inward from the annular portion 35a and engaged with grooves on the outer peripheral side of the filter body A.
Preferably, the outer retaining plate 35 is circumferentially divided and captured by the metal band 34.

[0017]

INDUSTRIAL APPLICABILITY As described above, the present invention is characterized in that both sides of a laminated body obtained by laminating ceramic short fibers and entwining them irregularly,
In an exhaust particulate filtration device in which a filter is formed by stacking reticulate bodies and curving in a tubular shape, one of the reticulate bodies is made of a conductive material, and the other is made of a non-conductive material. It has the following effects.

In particular, by energizing the conductive mesh on the back surface of the laminated body on which the exhaust particulate matter is deposited, the laminated body is rapidly and uniformly heated, and the collected exhaust particulate matter is re-combusted,
Regenerate the filter body.

By trapping the net-like bodies laminated on both sides of the laminate with each other by the heat-resistant wire rods penetrating the laminate, the heat of the net-like bodies can be quickly transferred to the laminate and the reburning of exhaust particulates. Can accelerate the playback time.

By sandwiching the net-like body made of a conductive material inside the laminate, the amount of heat dissipation can be suppressed and the laminate can be heated quickly.

[Brief description of drawings]

FIG. 1 is a front sectional view of an exhaust particulate filter according to the present invention.

FIG. 2 is a side sectional view of a filter body of the exhaust particulate filter device.

FIG. 3 is a side sectional view of a filter body of an exhaust particulate filter according to a modified embodiment of the present invention.

FIG. 4 is a front sectional view of a filter body of an exhaust particulate filter according to a modified embodiment of the present invention.

[Explanation of symbols]

A: Filter body 35: Outer side holding plate 35a: Ring part 35
b: Projection piece 37: Inner holding plate 37a: Annular portion 37
b: projection piece 51: inlet pipe 54: case 58: outlet pipe 59: blower 59a: air supply pipe 61, 63: reticulated body 72: inner space 73, 74: electrode

Claims (4)

[Claims] 1. An exhaust fine particle filtering apparatus comprising a filter body in which a mesh body is superposed on both surfaces of a laminated body formed by laminating ceramic short fibers and irregularly intertwined with each other, and is curved into a tubular shape. An exhaust particulate filter, wherein one of the bodies is made of a conductive material and the other is made of a non-conductive material. 2. One of the mesh bodies is stainless steel, Fe--
The exhaust particulate filter according to claim 1, wherein the mesh is a wire mesh made of a heat-resistant metal such as a Cr-Al alloy, and the other side of the mesh is a woven cloth made of a ceramic fiber such as SiC or alumina. 3. An exhaust fine particle filtering device in which a mesh body is laminated on both sides of a laminated body formed by laminating ceramic short fibers and irregularly intertwined with each other, and is then curved in a tubular shape to form a filter body. An exhaust particulate filter, characterized in that the body is made of a non-conductive material, and a net-like body made of a conductive material is sandwiched inside the laminated body. 4. A net-like body laminated on both sides of the laminate,
The exhaust particulate filtration device according to any one of claims 1 and 3, wherein the wire rods having heat resistance and penetrating the laminated body capture each other.