JPH05214922A - Particulate trap for diesel engine - Google Patents

Abstract

(57) [Abstract] [Purpose] To provide a particulate trap for a diesel engine in which the durability of a sealing material used for holding a filter block and sealing a gas to be treated is improved. A seal material 33 is used in which at least a part of an inorganic material 34 containing an inorganic substance exhibiting irreversible expansion is wrapped with a cloth 35 made of a thin metal plate and / or mainly fine metal wires.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a particulate trap suitable for trapping and removing particulates (fine particles) whose main component is carbon contained in exhaust gas of a diesel engine.

[0002]

2. Description of the Related Art In the exhaust gas of a diesel engine, particulates containing carbon as a main component have a considerable concentration (15
It is contained in 0-250 mg / Nm ³ ) and contributes to pollution along with nitrogen oxides. Therefore, various filters have been proposed to capture and remove particulates from the exhaust gas of diesel engines.

For example, Japanese Patent Laid-Open No. 57-35918 discloses a filter 1 as shown in FIG. This filter 1
A honeycomb type filter having a plurality of cells 3 which are divided by a filter wall 2 and extend in parallel to each other. In one end face A, about half of the end face opening of each cell 3 is closed by a blocker 4 in a checkered pattern. On the other end face B, the cell 3b opened on the one end face A is closed by the blocking member 5. When the exhaust gas of the diesel engine is introduced from one end face B of this filter 1, the exhaust gas is introduced into the cell 3a which is a dust-containing gas flow path and passes through the filter wall 2, and is contained in the dust-containing gas at that time. The particulates that are captured are trapped on the filter wall surface of the cell 3a, and the clean exhaust gas from which the particulates have been removed forms the clean gas flow path in the cell 3b.
Through the other end face A.

Further, Japanese Patent Laid-Open No. 56-124417 discloses a cross-flow type ceramic filter 20 as shown in FIG. This filter 20 has a rectangular parallelepiped outer shape as a whole, and a plurality of rectangular plate-like bodies 21 parallel to each other,
22 and ribs 23 and 25, and spacers 24 and 26. Of these, at least the plate-like body 22 is made of air-permeable porous ceramics having a filtering function.

The plate-like body 21 forms the uppermost surface and the lowermost surface of the filter 20, and the plate-like body 22 forms the intermediate surface. Adjacent plates
21 and 22 and the adjacent plate-like bodies 22 are parallel to each other, and the spacers 24 and the ribs 23 located in the middle part are both plate-like bodies.
It extends parallel to one side of 21. The upper edges of the ribs 23 and the spacers 24 are integrally in contact with the upper plate-like bodies 21 or 22, and the lower edges of the ribs 23 and the spacers 24 are the lower plate-like bodies.
It is in contact with 22 or 21.

As a result, a plurality of dust-containing gas flow paths 27 having openings at both ends are formed. While such ribs 23 and spacers 24 are provided on one side of the plate-like body 22,
A rib 23 and a spacer 24 are provided on the other side of the same plate 22.
A rib 25 and a spacer 26 extending in a direction orthogonal to the are provided. The ribs 25 and the spacers 26 have upper and lower edges integrally contacting the plate-like body 21 or the plate-like body 22 similarly to the ribs 23 and the spacers 24, though the extending directions are different.

Thus, a plurality of clean gas passages 28 are formed which are open at both ends and whose extending direction is orthogonal to the dust-containing gas passage 27. When this cross-flow filter 20 is used, one of the two end faces where the dust-containing gas flow path 27 is opened is directly or indirectly blocked, and the other end face is exhausted from the exhaust gas of the diesel engine. To introduce. Alternatively, the exhaust gas of the diesel engine is simultaneously introduced from the two open end faces of the dust-containing gas flow path 27.

Then, the plate-like body 22 serves as a filter wall, and the particulates are captured on the filter wall surface of the dust-containing gas passage 27, and the clean exhaust gas from which the particulates are removed is the clean gas passage.
After 28, it is leaked out of the system. In the particulate trap using such a filter, the particulates trapped on the filter wall surface of the filter accumulate, the filter is clogged, and the ventilation pressure loss of the exhaust gas gradually increases.

Therefore, in the particulate trap shown in Japanese Utility Model Laid-Open No. 62-35849, a burner is provided upstream of the exhaust gas inlet of the filter, and the particulates accumulated on the filter wall surface of the filter by the combustion gas from this burner. The curate is ignited, burned and incinerated.

In the particulate trap shown in Japanese Utility Model Laid-Open No. 56-92318, the exhaust gas flow passage is divided into two.
It has been proposed to divide the system into systems, arrange a particulate trap in each flow path, and alternately perform regeneration of the filter of the particulate trap and trapping of the particulate. In the regeneration in this case, the method of igniting the particulates on the filter, burning the particulates, and incinerating the particulates is adopted as in the above case.

However, in the above-mentioned conventional method in which the trapped particulates are burned on the filter, the filter is damaged by the heat of combustion of the particulates,
There is a problem that cracks are likely to occur in the filter due to thermal shock or temperature distribution. Furthermore, the exhaust gas of diesel engines contains a non-negligible amount of non-combustible components, and these non-combustible components are not removed by combustion and accumulate on the filter, which increases the ventilation pressure loss of the filter when operating for a long time. There was also a problem.

In order to solve these problems, Japanese Unexamined Patent Publication No.
256811 and JP-A-3-168313 propose a particulate trap as shown in FIG. That is, inside the casing 103, the cross-flow type filter 104 having a rectangular parallelepiped outer shape is housed via the band-shaped sealing material 32. The filter 104 is formed with a dust-containing gas passage 55 penetrating from the upper side to the lower side and a clean gas passage 62 whose one end is indirectly closed and the other end is opened to the side by a filter wall. ing.

As the filter 104, there is used a filter 104 formed by stacking filter elements 51 made of heat-resistant porous ceramics as shown in FIG.
This filter has an elliptical cross section of the dust-containing gas flow path, and the differential pressure of the backwash is applied to press the wall of the flow path having the elliptical cross section from the outside. In this case, the filter is not damaged fatally even if a high gas differential pressure is repeatedly applied, so that the reliability is excellent.

Each filter element 51 is made of a ceramic plate-like body having air permeability, and a pair of opposed end faces 53, 54 different from the wide main surface of the plate-like body are parallel to each other and penetrate the plate-like body. A plurality of holes 55 are open. In this example,
As the hole 55, a hole having an elliptical cross section is adopted, but a hole having a circular cross section, a polygonal hole such as a square or a hexagon, etc. can also be adopted.

The filter elements 51 are joined to the adjacent filter elements 51 by a thick heat-resistant adhesive 58. Of course, instead of the heat-resistant adhesive 58, a method of sandwiching packing etc. and compressing and pressing,
Alternatively, it is also possible to adopt a method in which a ceramic spacer is sandwiched between the filter elements 51 and baked to integrate them. Thus, between the filter elements 51, a slit-shaped clean gas flow path 62 partitioned by the adhesive 58 is formed so as to open at an end surface different from the opening surface of the hole 55. On the other hand, the hole 55 constitutes a dust-containing gas flow path for exhaust gas containing particulates.

In FIG. 3, an exhaust gas introduction pipe 102 of the particulate trap is connected to an exhaust pipe 100 of a diesel engine (not shown). Inside the casing 103 of the particulate trap, a cross-flow type filter 104 for trapping the particulates via the sealing material 32 is housed. A discharge pipe 38 is provided on the side of the filter 104 where the clean gas flow path 62 is opened, and a backwash nozzle 108 connected from a compressed air tank 105 to a pipe 106 via an electromagnetically driven valve 107 is arranged inside the exhaust pipe 38. , And in the exhaust pipe 100 connected downstream of the exhaust pipe 38,
An on-off valve 109 is arranged. As the on-off valve 109, for example, an exhaust brake butterfly valve used in a truck or the like is preferably used.

A particulate incineration unit 120 is attached to the particulate receiving unit 112 provided below the filter 104, and this particulate incineration unit is installed.
A discharge pipe 126 is connected to and communicates with the exhaust pipe 100 on the upstream side of the on-off valve 109, and an electromagnetically driven valve 125 is mounted in the middle of the discharge pipe 126. The particulate incinerator 120 does not necessarily need to communicate with the exhaust pipe 120, but has a preferable configuration from the viewpoint of simplifying the exhaust gas exhaust system, that is, from the viewpoint of reducing the exhaust gas outlet of the exhaust pipe.

The electromagnetically driven valve 125 is closed during the backwash operation, and the discharge of gas from the particulate incinerator 120 is closed, so that the exhaust gas containing particulates is discharged to the outside of the system during the backwash operation. Is designed to prevent Further, the particulate incineration section 120 is connected to the compressed air tank 105 and the pipe 106 in order to ensure the particulate combustion even when the ignition means 121 including an electric heater and the oxygen concentration in the exhaust gas are low. A combustion air supply nozzle 122 is arranged.

The combustion air supply nozzle 122 has an outer diameter of 8 m.
A stainless steel pipe with m and a wall thickness of 0.3 mm is used. The supply amount of combustion air depends on the operating conditions, that is, the exhaust gas emission amount, the oxygen concentration in the exhaust gas, the exhaust gas temperature,
Although it is set according to the capacity of the electric heater, in this embodiment, it is set to 15 to 30 liters / min. Further, an orifice plate 128 for controlling the flow rate of the exhaust gas flowing out from the particulate incinerator 120 to 0.2 to 5% of the total exhaust gas flow rate is arranged at the connection portion of the particulate incinerator 120 with the exhaust pipe 126. Has been done. The compressed air tank 105 is connected to a compressor (not shown) via a pipe 106.

The electric heater 121 is set to have a surface temperature of 600 to 800 ° C. in order to surely ignite the particulates and ensure the durability of the electric heater itself. As the sheath material, a metal having corrosion resistance to an acidic substance such as sulfuric acid component in exhaust gas, for example, stainless 310S or Inconel 600 is used.

In a particulate trap for a diesel engine which performs a backwash operation, a sealing material for holding a filter in a casing and partitioning a dust-containing gas passage and a clean gas passage of the filter is disclosed in JP-A-3-68313. An improved sealing material and sealing method have been proposed. That is, the sealing material is held between the stoppers provided at the boundary between the dust-containing gas flow path side space and the clean gas flow path side space, and the sealing material is mainly an inorganic material containing ceramic fibers and an inorganic expansive substance. Wrapped in a cloth made of quartz glass fiber can be used.

It is said that the sealing material having such a structure is unlikely to deteriorate, and that the sealing material is not easily frayed and scattered even during long-term operation. However, in addition to the pressure difference during backwash operation, even in the case where it is mounted on an automobile and repeatedly subjected to severe vibration, heating and cooling during use for a long time, even if the above sealing material is used, the durability is insufficient. It turned out to be enough.

[0023]

In conventional particulate traps for diesel engines, the durability of the sealing material is still insufficient, and heating and cooling are repeated during long-term operation, differential pressure during backwashing, and vehicle Vibration is added,
There is a problem that the sealing material is loosened and the surface of the sealing material is frayed, the sealing material scatters, and finally the sealing material is lost and the particulates leak out.

In particular, in the case of a particulate trap having a backwashing means, the pressure on the clean gas passage side becomes high during the backwashing operation, so that a force for pushing the sealing material holding portion and the casing is applied to remove the sealing material. In addition to the loosening of the fixing force, there is a problem that the scattering of the sealing material is promoted by hitting the sealing material with a pulsed high pressure backwash flow. The present invention is intended to solve these problems and provide a highly reliable particulate trap for a diesel engine, which is fixed by a durable sealing material.

[0025]

The present invention has been made to solve the above-mentioned problems, and a particulate trap for a diesel engine of the present invention is provided with a dust-containing gas passage defined by a filter wall and a clean A ceramics filter having a gas flow path is held inside a metal casing through a sealing material, and a filter is provided by backwashing in which compressed gas is blown into the clean gas side of the filter and flowed to the dust-containing gas flow path side. A particulate trap for a diesel engine, wherein a filter is regenerated by removing trapped particulates, wherein the sealing material is an inorganic material containing an inorganic substance exhibiting irreversible thermal expansion, a thin metal plate and / or Alternatively, it is characterized in that it is at least partially wrapped with a cloth mainly composed of metal fine wires.

In a preferred embodiment of the particulate trap for a diesel engine of the present invention, the inorganic substance exhibiting irreversible thermal expansion is vermiculite, and the inorganic material is at least partially wrapped with a cloth made of glass fiber. .. In another preferred embodiment of the particulate trap for a diesel engine of the present invention, the inorganic material contains glass or ceramic fibers, and the cloth made of glass fibers is a cloth made of quartz glass or non-alkali glass fibers.

In another preferred embodiment of the particulate trap for a diesel engine of the present invention, the metal thin plate and / or the cloth mainly made of metal fine wire is made of metal fine wire mainly containing either aluminum or copper. .. Ceramics with excellent heat resistance and corrosion resistance are used as the material of the filter, but especially cordierite, β-spodumene, alumina silica keatite, etc., which has high thermal shock resistance due to its small thermal expansion coefficient, can be preferably used. ..

The filter has a dust-containing gas passage and a clean gas passage defined by a filter wall, and the dust-containing gas passage and the clean gas passage are separated by a sealing material, for example, A honeycomb type filter as shown in FIG. 5 and a cross flow type filter as shown in FIG. 6 can be used, and in particular, a filter having a circular or elliptical cross section of the dust-containing gas flow channel shown in FIG. 4 can be preferably used.

As a method of regenerating these filters, there are a combustion incineration method in the filter in which the captured particulates are ignited by a heater or a burner and a backwash method with high-pressure gas, but the particulates contain incombustibles. Therefore, it is preferable to use the backwash method because it can prevent an increase in ventilation pressure loss and can eliminate the heat damage when burning the particulates. In particular, in the case of a backwashing type particulate trap, since the sealing material is easily loosened and scattered by the pulsed flow of the high-pressure gas, a sealing material having excellent durability and sealing force is required.

The characteristics required of the sealing material include sufficient elasticity to function as a cushioning material for holding the filter in the casing, blocking of passage of particulates, and more than about 400 ° C. It has heat resistance. An inorganic material containing an inorganic material exhibiting irreversible thermal expansion is responsible for the function of imparting the sufficient holding strength and elasticity. Sealing material made of an inorganic material that contains an irreversible thermal expansion inorganic material expands and develops a more reliable sealing property by heat treatment after mounting the sealing material or by heating during use. However, there is a weak point that the shape retention of the sealing material itself is deteriorated after being heated, and the sealing material tends to scatter.

As the inorganic substance exhibiting irreversible thermal expansion, there are vermiculite, perlite and the like. Vermiculite is an easily available raw material, and the temperature at which expansion starts is about 400 ° C. It is a suitable material for the sealing material of In an inorganic material containing an inorganic substance exhibiting irreversible thermal expansion, an inorganic binder such as water glass or an organic binder such as a phenol resin is added,
A product obtained by mixing inorganic fibers such as glass fibers and ceramic fibers and molding them can be more preferably used.

Further, an inorganic material in which at least a part of the inorganic material containing an inorganic material having an irreversible thermal expansion property formed as described above is further covered with a glass fiber cloth can be preferably used. As the glass fiber cloth, a cloth made of quartz glass fiber or non-alkali glass fiber having good heat resistance can be preferably used, and depending on the use conditions of the particulate trap, those fibers are used alone or in combination. used. Examples of the form of combined use include partial use of quartz glass fiber cloth and non-alkali glass fiber cloth, or mixed spinning of both fibers, and mixed weaving.

Here, the quartz glass fiber has the advantage of high heat resistance, while it is rather brittle, and the alkali-free glass fiber has the heat resistance inferior to quartz glass, but has the advantage of excellent flexibility. The cloth coating of glass fiber partially or wholly covers an inorganic material containing an inorganic material exhibiting irreversible thermal expansion property or an inorganic material containing an inorganic fiber such as glass fiber or ceramic fiber. However, it is more preferable to cover the entire surface in order to secure the durability of the sealing material.

The sealing material used in the particulate trap for a diesel engine of the present invention is obtained by coating at least a part of the above-mentioned inorganic material with a thin metal plate and / or a cloth mainly composed of fine metal wires. It is more preferable to cover the entire surface in order to secure the durability of the sealing material. When coating a portion of the inorganic material, the corners or ends of the filter are typically coated relatively easily.

As the metal material of the metal thin plate and / or the cloth containing the metal fine wire, various metals such as nickel, iron, stainless steel, aluminum, copper, etc. are used if they have a melting point of 500 ° C. or more and are not too hard. However, it is preferable to use aluminum or copper, which has good malleability and is easily available. If aluminum or copper is used, it is more malleable than other metals, so that it is possible to easily form a seal with good adhesion to the wrapping inorganic material and the casing.

When using these metal materials, it is preferable to select and use a soft material such as mild steel that has been annealed in advance. Further, since iron, stainless steel, etc. have higher heat resistance than aluminum, copper, etc., it is preferable to select iron, stainless steel, etc. under the use condition of contacting with a high temperature gas of 700 ° C. or higher. The thickness of the thin metal plate varies depending on the use conditions and the material, but is preferably 0.3 mm or less in order to ensure flexibility. But,
When the thickness is 0.005 mm or less, it is not preferable because the metal thin plate is likely to be damaged due to tightening force during mounting, mechanical vibration during use, expansion and contraction of the casing and the inorganic sealing material due to heating and cooling.

Considering the ease of use, the sealing property and the reliability, the more preferable thickness of the metal thin plate is 0.005 mm.
It is 0.1 mm or less. The reason for this is that if the thickness is 0.1 mm or more, the flexibility is slightly inferior, so it is necessary to make the tightening force at the time of setting sufficiently strong so that the thin metal plate is brought into close contact, and some filters may be damaged during tightening. .. When wrinkles are formed on the thin metal plate, the seal is often incomplete.

A cloth mainly composed of thin metal wires is a preferable covering material because it is more flexible than a thin metal plate even if it is composed of the same metal. As the cloth mainly composed of the metal fine wire, a cloth woven only with the metal fine wire, or a cloth woven by mixing the metal fine wire with inorganic fibers such as glass fiber and ceramic fiber can be used. Heat-resistant quartz glass fibers or non-alkali glass fibers can be used as glass fibers, and alumina fibers, mullite fibers, and ceramic fibers can be used as ceramic fibers.
Zirconia fibers and the like can be used. In the present invention, the cloth mainly composed of thin metal wires means a cloth composed of 50% by volume or more of thin metal wires. There are various weaves such as a plain weave and a twill weave for a cloth including fine metal wires, but it is preferable that the cloth be as tightly packed as possible in order to prevent the scattering of the inorganic material inside, and the sealing property. Therefore, it is preferable to use a cloth that is elastic to some extent, is flexible, and is easily deformed.

A cloth woven only with fine metal wires has excellent stretchability, but may have problems in heat resistance, acid resistance and the like depending on the application. A woven fabric obtained by adding inorganic fibers to thin metal wires has improved heat resistance, acid resistance, etc., but tends to be brittle and lose elasticity. Therefore, in the case of adding inorganic fibers to the metal thin wire and weaving, it is preferable that the amount of the inorganic fibers is 50% by volume or less. The thickness of the thin metal wire differs depending on the use conditions of the filter in the particulate trap and the type of metal material. Generally, the wire diameter is 0.3 mm or less to ensure flexibility, but preferably 0.1 mm
It is below. Due to good adhesion and ease of use, the wire diameter is 0.
It is more preferable to use a fine metal wire having a diameter of 02 mm or less after spinning. If the wire diameter is 0.1 mm or more, the cloth becomes thick and the elasticity of the cloth deteriorates a little, so it is necessary to tighten tightly at the time of installation to ensure close contact, and if the cloth has wrinkles, tighten it. Seal leakage may occur depending on the degree of.

The covering of the inorganic material with a thin metal plate and / or a cloth mainly composed of fine metal wires is performed in accordance with the shape of the filter,
Depending on the shape of the casing and the like, both total coating and partial coating can be appropriately applied. In the case of partial coating, it is effective to coat the sealing material in a region where scattering of the sealing material is likely to occur, for example, in the case where the inorganic sealing material is in a band shape, both ends thereof, or the middle portion thereof in a spiral shape. In some cases, such partial coating is preferable as a sealing material because wrinkles are less likely to occur.

Comparing the case where a thin metal plate is used with the case where a cloth mainly composed of thin metal wires is used, it is easy to obtain a commercially available thin metal plate, but wrinkles are likely to occur at the time of attachment, and a thin one is in use. Whereas troubles such as tearing may occur, cloth mainly composed of thin metal wires
Since it is easy to bend and bend, it is easy to install, wrinkles do not easily occur, and it is difficult to tear during use, and it has excellent characteristics such as excellent durability and reliability.

[0042]

EXAMPLES Examples of the present invention will be shown below, but the present invention is not limited to these examples.
FIG. 1 shows a state in which the seal material 33 is attached to the cross-flow filter 104 shown in FIG.
A band-shaped sealing material 33 is attached around the upper and lower ends of 61 with an adhesive. The diesel engine particulate trap shown in FIG. 3 incorporates the filter of FIG. 1, and FIG. 2 is a partial cross-sectional view showing a portion in which the filter 61 is held in the casing 103 by the sealing material 33. is there.

Here, the sealing material 33 is covered with a cloth 35 made of a thin metal plate or mainly a fine metal wire, which is an inorganic material 34 containing alumina-silica ceramic fibers in addition to vermiculite which is an inorganic substance exhibiting irreversible thermal expansion. Has been done. In the figure, the band-shaped inorganic material 34 is entirely wrapped with a sheet-shaped thin metal plate or a cloth 35 mainly made of thin metal wires. If the cloth 35 that is made of a thin metal plate or mainly metal wires is preliminarily processed into a tubular shape, wrinkles are less likely to occur and it is easy to use. In this case, after inserting the inorganic material into the cylinder, both ends are folded, crimped, sewn and the like to be closed. The same attachment method is adopted when only both ends are covered.

Test Example In the test example, the cordierite-based ceramics filter having the structure shown in FIG. 4 was formed with various sealing materials having the structures shown in Table 1 and the structure shown in FIG. 1 and FIG. The performance of the sealing material was tested by incorporating it in a particulate trap device having the configuration shown.

[0045]

[Table 1]

However, the alkali-free glass fiber sheet of inorganic material used in Test Example 1 of Table 1 has a fiber diameter of 5 μm,
5 sheets of 5 mm to 10 mm long fibers made into 1 mm thick paper
The vermiculite sheet used in Test Examples 2 to 9 is a commercially available product containing ceramic fibers and an organic binder (Intalam Mat, a product handled by Sumitomo 3M).
The cloth made of quartz glass fiber used in Test Examples 3, 4, 7, 8 and 9 was a cloth having a fiber diameter of 13 μm woven into a tubular shape. The end face of the vermiculite sheet containing the inorganic substance exhibiting irreversible thermal expansion is not covered with the quartz glass fiber cloth.

The blended cloth of Test Example 6 used for coating was 70% by weight of stainless fine wire and 30% by weight of quartz glass fiber.
Is a tubular twill weave product. In the case of coating both ends, the end of the inorganic material was coated by about 20 mm, and in the case of Test Example 4 coated in a spiral shape, a thin plate with a width of 15 mm was wound so that about 30% of the whole was exposed. It was attached. The conditions of the tests conducted are as shown in Table 2.

[0048]

[Table 2]

As a result of the above test, in Test Example 9, the total operation time of the intermittent operation was about 250 hours, the number of backwashing was about 1500 times, and a part of the sealing material was scattered to cause the leakage of particulates. After that, it became impossible to collect particulates. Further, in the case of Test Example 1, a gap was formed between the seal material and the casing after about 500 hours under the same operating conditions and about 3000 times of backwashing, and particulate leakage occurred. However, there is no abnormality in the aluminum thin plate,
No scattering of inorganic material occurred.

In the case of Test Example 2, approximately 8 under the same operating conditions.
The leakage of particulates occurred at 00 hours and about 4,800 backwashing cycles. The leak originated from the wrinkles in the Inconel sheet, which was thought to have been created during installation. Also in this case, the inorganic sealing material did not scatter. Test example 3
In the cases of ~ 8, no abnormalities were found in the seal material even after about 1000 hours under the same operating conditions and about 6000 times of backwashing, and no leakage of particulates occurred at all. The differential pressure during backwashing under this test operating condition was 4
600 mm, and the differential pressure during normal operation is 1250 in the water column.
It was mm.

[0051]

With the particulate trap for a diesel engine of the present invention, it is possible to reliably prevent leakage of particulates due to scattering and damage of the sealing material of the filter, and continuous operation for a long period of time becomes possible. And because the life of the sealing material, which was the neck of the maintenance of the particulate trap, is extended, the maintenance-free period of the particulate trap is significantly extended,
It is now possible to drive trucks and buses without worrying about the maintenance of the particulate trap. In the case of the particulate trap of the present invention, not only scattering of the sealing material but also damage to the sealing material was not recognized, damage at the time of mounting the sealing material was unlikely to occur, and the effect of easy mounting was also obtained.

[Brief description of drawings]

FIG. 1 is a perspective view showing an example in which a sealing material is attached to a filter used in a particulate trap for a diesel engine of the present invention.

FIG. 2 is a partial cross-sectional view of a portion of the particulate trap filter according to the present invention held by a sealing material.

FIG. 3 is a cross-sectional view for explaining an example of the configuration of a particulate trap for a diesel engine of the present invention.

FIG. 4 is a perspective view showing a filter preferably used in the particulate trap of the present invention.

FIG. 5 is a perspective view showing another example of a filter that can be used in the particulate trap of the present invention.

FIG. 6 is a perspective view showing still another example of a filter that can be used in the particulate trap of the present invention.

[Explanation of symbols]

 32, 33: Sealing material 34: Inorganic material 35: Metal thin plate or cloth mainly made of thin metal wire 36: Stopper 61, 104: Cross flow type filter 55: Dust-containing gas flow path 62: Clean gas flow path 100: Exhaust pipe 102 : Inlet pipe 103: Casing 105: Compressed air tank 107: Electromagnetically driven valve 108: Backwash nozzle 109: Open / close valve 120: Particulate incinerator 122: Incinerator air supply nozzle 121: Electric heater 125: Solenoid valve 128: Orifice plate

Claims (6)

[Claims] 1. A ceramics filter having a dust-containing gas flow path and a clean gas flow path, which are divided by a filter wall, is held inside a metal casing through a sealing material, and a compressed gas is used to clean the filter. In the particulate trap for diesel engine, where the filter is regenerated by blowing off the particulate flow path to the dust-containing gas flow path side and removing the particulates trapped in the filter by backwashing, the sealing material is irreversible. A particulate trap for a diesel engine, characterized by comprising at least a part of an inorganic material containing an inorganic substance exhibiting various thermal expansions, covered with a thin metal plate and / or a cloth mainly composed of fine metal wires. 2. The particulate trap for a diesel engine according to claim 1, wherein the inorganic substance exhibiting irreversible thermal expansion is vermiculite, and the inorganic material is at least partially wrapped with a cloth made of glass fiber. 3. The diesel engine patty according to claim 1 or 2, wherein the inorganic material contains glass or ceramic fibers, and the cloth made of glass fibers is mainly made of quartz glass fibers or non-alkali glass fibers. Curate trap. 4. The diesel engine particulate according to any one of claims 1 to 3, wherein the metal thin plate and / or the cloth mainly made of metal thin wires is made of metal thin wires mainly containing aluminum or copper. trap. 5. A particulate trap for a diesel engine according to claim 1, wherein the thin metal plate has a thickness of 0.005 mm or more and 0.1 mm or less. 6. A particulate trap for a diesel engine according to claim 1, wherein the fine metal wire has a diameter of 0.1 mm or less.