JPH084698B2 - Particulate trap device - Google Patents

Description

TECHNICAL FIELD The present invention relates to a particulate trap device for collecting and cleaning fine particles (particulates) from a dust-containing gas such as diesel engine exhaust gas, and particularly to fine particles. The present invention relates to a seal structure for accommodating an AC filter that collects air in a casing.

"Prior Art" Diesel engine exhaust gas contains a considerable amount of fine particles, mainly carbon, which causes pollution. Therefore, various particulate trap devices for collecting and removing fine particles from the exhaust gas of a diesel engine have been proposed.

As a filter used in such a particulate trap device, for example, a filter 10 as shown in FIG. 8 is known. This filter 10 has a basic structure of a honeycomb body which is partitioned by cell walls 11 made of air-permeable porous ceramics and which has a large number of cells 12 and 13 adjacent to each other with the cell walls 11 as boundaries. The cells 12 and 13 are arranged alternately in a checkered pattern on the end faces, and all extend parallel to the longitudinal direction. The cell 12 is opened at one end face 15 of the filter body 10 and is closed at the other end face 16 opposite to it, and the cell 13 is closed at one end face 15 of the filter body 10 and opened at the other end face 16 opposite to it. ing. In this filter 10, when diesel engine exhaust gas is introduced from one end surface 15 into the cell 12, the cell wall 11 serves as a filter to collect fine particles on the inner surface of the thin wall 11, and clean exhaust gas from which fine particles have been removed. Flows out of the other end face 16 through the cell 13.

Also, a filter made of ceramics as shown in FIG.
Twenty is also known. The filter 20 has a rectangular parallelepiped outer shape as a whole, and a plurality of parallel filters (6 in FIG. 9).
It is composed of rectangular plate-like bodies (21, 22), ribs (23, 25), and spacers (24, 26). These plates 21, 2
2. The ribs 23, 25 and the spacers 24, 26 are all made of breathable porous ceramics having a filter function. The plate-like body 21 forms an upper surface and a lower surface of the filter 20, and the plate-like body 22 forms an intermediate surface. Between adjacent plate-shaped bodies 21 and 22, or between 22 and 22, ribs 23 located at the ends and spacers 24 located in the middle extend in parallel to one side of the plate-shaped bodies 21. The upper edges of the ribs 23 and the spacers 24 are in contact with the upper plate body 21 or 22, and the lower edges of the ribs 23 and the spacers 24 are in contact with the lower plate body 22 or 21. . This allows multiple dust-containing gas passages to be opened at both ends.
27 is formed. While such ribs 23 and spacers 24 are provided on one side of the plate-like body 22, the same plate-like body is provided.
A rib 25 and a spacer 26 that extend in a direction orthogonal to the rib 23 and the spacer 24 are provided on the other side of 22.
The rib 25 and the spacer 26 are essentially the same as the rib 23 and the spacer 24, respectively, except that the traveling directions are different. Thus, a plurality of clean gas passages 28 are formed which are open at both ends and whose traveling direction is orthogonal to the dust-containing gas passage 27. This filter 20
In the above, one of the two end faces where the dust-containing gas passage 27 opens is directly or indirectly closed, and the diesel exhaust gas is introduced from the other end face. Alternatively, the diesel exhaust gas is simultaneously introduced inward from the two end surfaces of the dust-containing gas passage 27 which are open. Then, the plate-shaped body 22 serves as a filter surface, and the fine particles are collected on the surface of the dust-containing gas passage 27 of the plate-shaped body 22. It flows out of the system through the passage 28.

By the way, the filter having the honeycomb structure shown in FIG. 8 has a prismatic shape as a whole, and an inlet for the dust-containing gas is formed on one of the facing end faces, and an outlet for the clean gas is formed on the other end face. The seal can be achieved with a relatively simple structure when the is housed in the casing of the particulate trap device. For example, Japanese Patent Laid-Open No. 57-1292
As shown in No. 14, there is a structure that seals only between the outer peripheral surface of the filter and the rectangular tubular casing,
As shown in No. 3, a seal structure or the like adopted in the conventional honeycomb type catalytic converter for automobiles may be used.

However, when using a so-called AC type filter in which the dust-containing gas passage and the clean gas passage intersect each other as shown in FIG. 9, the sealing structure is complicated. That is, when an AC type filter is used, a total of four surfaces, that is, a pair of surfaces in which the dust-containing gas passage is opened and a pair of surfaces in which the clean gas passage is opened, are sealed. Therefore, it is difficult to seal with sufficient airtightness,
Further, since the weight increases, it is unsuitable as an automobile part for which weight reduction is desired.

Further, in the structure in which the fine particles collected in the filter are blown off by backwashing to regenerate the filter, the casing must have the strength to withstand the pressure rise during backwashing. As a structure that is lightweight and has such strength, a cylindrical or elliptic cylinder-shaped casing like a conventional muffler is desirable, but the above AC type filter is housed in such a casing and its four faces are sealed. Was virtually impossible.

"Problems to be Solved by the Invention" The present invention has been made in view of the above-mentioned problems of the conventional art, and an object thereof is an AC type in which a dust-containing gas passage and a clean gas passage are formed to intersect with each other. An object of the present invention is to provide a particulate trap device in which, when the filter of (1) is housed in a casing, the sealing structure thereof is simplified, and the filter can be sealed regardless of the shape of the casing.

[Means for Solving the Problem] In order to achieve the above object, the present invention is configured such that a dust-containing gas passage and a clean gas passage, which are partitioned by a partition wall made of an air-permeable porous material, intersect with each other to form a dust-containing gas passage. An AC type filter in which the surface where the gas passage is opened and the surface where the clean gas passage is opened are not parallel is housed in a casing having a dust-containing gas inlet and a clean gas outlet, and the dust-containing gas inlet is in the dust-containing gas passage. In the particulate trap device configured to communicate with each other and the clean gas passage to communicate with the normal gas outlet,
A sealing material is applied only to a pair of opposing end faces of the filter, in which one of the dust-containing gas passage and the clean gas passage of the filter is opened, and a seal is provided between the casing and the casing. And

In the present invention, the filter has a plurality of holes formed by penetrating a pair of opposing end faces of a plate-like body made of a gas permeable porous material so that the plate-like bodies are aligned in the traveling direction of the holes. Are arranged in parallel with each other, and these plate-like bodies are joined to each other through ribs or spacers extending in a direction intersecting the traveling direction of the holes, and the ribs or spacers are used to connect the plate-like bodies to each other. It is preferable that the hole is formed by forming another passage penetrating in a direction intersecting with the hole.

Further, in the present invention, the filter is formed of porous ceramics, and the sealing material is formed of a heat-expandable mat formed by bonding a heat-expandable material and a ceramic fiber with an organic binder. Is preferred.

"Operation" In the present invention, as described above, either one of the dust-containing gas passage and the clean gas passage of the AC type filter is opened,
The sealing material is applied only to a pair of opposing end faces of the filter, and a seal is provided between the filter and the casing.

More specifically explaining this, for example, if only the surface where the clean gas passage is open is sealed, the dust-containing gas introduced from the dust-containing gas inlet of the casing is introduced to the dust-containing gas passage of the filter. It also fills the inner space of the casing. However, since the opening of the clean gas passage of the filter is sealed with the casing as described above, the dust-containing gas is prevented from leaking to the clean gas passage. Eventually, the dust-containing gas is introduced into the clean gas passage only through the air-permeable partition wall of the filter, the fine particles contained at that time are collected into the clean gas, and flow out through the clean gas passage through the clean gas outlet. . Even when only the pair of opposed end faces of the filter, in which the dust-containing gas passage of the filter is open, is sealed, the dust-containing gas is prevented from leaking to the clean gas passage in the same manner.

The present invention was made in view of the fact that it is possible to prevent the dust-containing gas from leaking into the clean gas passage by sealing only the surface of the filter where either the dust-containing gas passage or the cleaning gas passage is open. Is. As a result, it suffices to seal only the pair of end faces of the filter facing each other, and even if the casing has any shape such as a cylindrical shape, an elliptic cylinder shape, or a bellows cylinder shape, the sealing surface can be formed. By arranging the filter in the cylinder axis direction,
It can be easily and surely sealed.

In the present invention, as a filter, a plurality of holes are formed by penetrating a pair of opposing end faces of a plate-shaped body, and the plate-shaped bodies are arranged in parallel so that the traveling directions of the holes are aligned, The plate-like bodies are joined to each other via ribs or spacers extending in a direction intersecting the traveling direction of the holes, and the ribs or spacers penetrate the plate-like bodies in the direction intersecting the holes. By using the one having the passage formed therein, it is possible to give strength enough to withstand the pressure at the time of backwashing for regeneration of the filter.

In the present invention, if the filter is formed of porous ceramics and the sealing material is formed of the above-mentioned expanded expandable mat, it provides sufficient heat resistance and sealing property when applied to the treatment of high temperature exhaust gas. be able to.

[Embodiment of the Invention] FIG. 1 shows a filter storage structure in a particulate trap device embodying the present invention.

In this embodiment, two filters 31 are arranged in series and housed in a cylindrical casing 32.
In this embodiment, as the filter 31, Japanese Patent Application No. Sho 62-301586 is used.
It uses something like that shown in the issue. However, it is also possible to use the filter as shown in FIG. 9 described above.

The filter 31 has, as a basic element, a plate-like body 33 made of air-permeable porous ceramics shown in FIG. The plate-shaped body 33 has a pair of opposed end faces 3 different from the main surface.
A plurality of holes 36 are formed through the holes 4 and 35. This hole 3
As the shape of 6, various shapes such as a circle, an ellipse, a square, and a hexagon when viewed from the opening can be adopted. Hole in plate 33
At the pair of edge portions along the end faces 34, 35 where 36 opens, the holes 36
The rib 37 protruding in the direction perpendicular to the axial direction of the end surface 34,
It extends along 35.

As shown in FIG. 3, the filter 31 is formed by stacking a plurality of the plate-like bodies 33. The plate 33 has holes 36.
The ribs 37 are overlapped so that their traveling directions are aligned and are oriented in the same direction. An end surface of the rib 37 in the projecting direction is attached to the adjacent plate-like body 33 with a heat-resistant adhesive, pressure tightening,
They are hermetically joined by means such as reaction sintering.
As a result, another passage 38 defined by the rib 37 is formed in the gap of the plate-like body 33 so as to open on a surface different from the opening surface of the hole 36. In this embodiment, the hole 36 of the filter 31 is used as the dust gas passage, and the passage 38 is used as the clean gas passage.

Referring again to FIG. 1, in the two filters 31, the surface on which the clean gas passage 38 'opens is directed in the cylinder axis direction of the casing 32, and the surface on which the dust gas passage 36' opens is directed in the vertical direction. They are arranged to match each other. Frame-shaped sealing members 39 are arranged on the surfaces of the two filters 31 where the clean gas passages 38 'are opened. In the case of this embodiment, the sealing material 39 is arranged between the two filters 31 and at a total of three positions on both sides when the two filters 31 are connected.

As the sealing material 39, a heat-expandable mat formed by bonding a heat-expandable material such as vermiculite or perlite and a ceramic fiber containing alumina, silica or the like as a main component with an organic binder is used. The sealing material 39 shown in FIG. 1 is, for example, a mat having a thickness of 5 m / m, which is cut out in a frame shape with a width of 20 mm. Such a heat-expandable mat has a bulk density of about 0.2 to 1.2 g / cm ³ , a normal maximum operating temperature of 800 ° C, and a thermal conductivity of 0.1 to 0.2 Kcal / m ・ hr ・ ° C at 600 ° C.
Such is the case, and examples thereof include “Intramu Matt” (trade name, manufactured by Sumitomo 3M Limited). The heat-expandable mat has the property of expanding in the thickness direction, for example, about 1.5 to 3 times in the thickness direction when heated to a certain degree, and maintaining the expanded state even after repeated heating and cooling,
When applied to the treatment of high-temperature exhaust gas and the like, it is possible to absorb the difference in thermal expansion between the ceramic filter 31 and the metallic casing 32, and to maintain a sufficient sealing property.

The two filters 31 are accommodated in the casing 32 with the sealing material 39 applied thereto as described above. Then, the opening of the casing 32 is covered with the lid plate 40, and bolts are inserted into the holes 41 formed in the peripheral portion of the lid plate 40 and the holes 43 formed in the flange portion 42 of the casing 32 to fasten and fix them. . When the cover plate 40 is tightened, the filter 31 and the sealing material 39 are pressed against each other in the cylinder axis direction of the casing 32, and the sealing material 39
And the filter 31 is fixed in the casing 32.

4 and 5 show the filter as described above.
There is shown a particulate trap device according to the present invention constructed by incorporating 31 into a casing 32. In this embodiment, as the basic structure of the particulate trap device, a structure as shown in Japanese Patent Application No. 62-232232 is adopted.

The filter 31 includes a support portion 4 provided in the casing 32.
It is placed at 4, 45. The support portion 44 supports both sides of the joined filter 31, and the support portion 45 supports the joined portion of the filter 31. An exhaust gas introduction pipe 46 of a diesel engine is connected to the upper part of the cover plate 40. Exhaust gas introduction pipe 46
Is for forming the dust-containing gas inlet in the present invention. Further, a cover 47 that closes the opening of the lid plate 40 is attached. On the other hand, a conical cover 48 is attached to the end surface of the casing 32 opposite to the cover plate 40, and an exhaust gas outlet pipe 49 is attached to the cover 48. Exhaust gas discharge pipe 49
Is a component of the clean gas outlet in the present invention. Further, the exhaust gas outlet pipe 49 is provided with a passage opening / closing valve 51 that is operated by the electromagnetic solenoid 50. further,
The tip of the backwash nozzle 52 is inserted into the cover 48. From the tip of the backwash nozzle 52, high-pressure gas is jetted from a high-pressure tank (not shown) via a valve 53.

A plurality of openings 54 are provided in the lower surface of the casing 32, and an auxiliary filter 55 is attached to the openings 54.
Further, an electric resistance heater 56 is attached on the auxiliary filter 55.

Two filters connected in the axial direction of the casing 32
As described above, the dust-containing gas passage 36 ′ that runs up and down the casing 32 and the clean gas passage 38 ′ that extends in the cylinder axis direction of the casing 32 are formed inside the casing 31.

Next, the operation of the particulate trap device according to the present invention will be described.

Exhaust gas from the diesel engine is exhaust gas introduction pipe 46
And is introduced into the upper space of the casing 32. Most of the exhaust gas flows into the dust-containing gas passage 36 'of the filter 31 as indicated by the solid arrow in FIG. Part of the exhaust gas is the sixth
As shown in the drawing, it passes through the gap between the filter 31 and the casing 32, goes around on both sides of the filter 31, and fills the inside of the casing 32. However, as described above, the clean gas passage 38 '
Is hermetically sealed to the inner wall of the casing 32 by the sealing material 39, so that the exhaust gas passes through the clean gas passage 3
Leakage into 8'is prevented. Eventually, the exhaust gas flows from the dust-containing gas passage 36 'of the filter 31 into the clean gas passage 38' through the partition wall of the filter 31. At that time, fine particles are captured by the partition walls of the filter 31 and cleaned. Thus, the exhaust gas becomes clean gas and flows into the clean gas passage 38 ′, passes through the clean gas passage 38 ′ and enters the cover 48 as shown by the double-dashed line arrow in FIG. Is discharged. A part of the exhaust gas flows to the outside through the opening 54 at the bottom of the casing 32, and at that time, the particles are captured by the auxiliary filter 55 attached to the opening 54.

Part of the fine particles captured by the partition wall of the filter 31 falls in the dust-containing gas passage 36 'and accumulates on the auxiliary filter 55 at the bottom of the casing 32, while the remaining part of the fine particles is in the dust-containing gas passage 36'. It adheres to the inner wall and accumulates. If the amount of particulates deposited on the inner wall of the dust-containing gas passage 36 'increases, the pressure loss of exhaust gas increases, which adversely affects the output of the engine. Therefore, it is necessary to periodically perform backwashing to regenerate the filter 31.

The backwash operation is performed by first operating the electromagnetic solenoid 50 to temporarily close the flow passage opening / closing valve 51 provided in the exhaust gas outlet pipe 49, open the valve 53, and eject high-pressure gas from the backwash nozzle 52. Done. The high-pressure backwash gas fills the clean gas passage 38 ', and the filter 31 is supplied from the clean gas passage 38' side.
Through the partition wall to flow into the dust-containing gas passage 36 ', and the fine particles accumulated on the inner wall of the dust-containing gas passage 36' are removed. The particles that have been blown off fall down through the dust-containing gas passage 36 'and are collected on the auxiliary filter 55. The backwash gas is ejected in an extremely short time, and when the backwash operation is completed, the electromagnetic solenoid 50 is actuated again to open the passage opening / closing valve 51. Although the output of the engine is temporarily reduced by closing the flow passage opening / closing valve 51, two sets of this particulate trap device are provided to branch the exhaust pipe of the diesel engine to mount two sets of particulate traps. The above problem is solved by connecting and alternately performing backwash in the branched flow paths.

Thus, the fine particles are finally collected on the auxiliary filter 55. When the amount of fine particles reaches a certain amount, the electric resistance heater 56 is heated to burn and remove the fine particles. Since the fine particles contain a trace amount of non-combustible component, when the engine is operated for a long period of time, the non-combustible component is deposited on the auxiliary filter 55 and impairs the air permeability of the auxiliary filter 55. In such a case, the lower opening of the casing 32
It suffices to open 54 and remove the incombustible component on the auxiliary filter 55.

By passing the high-temperature exhaust gas, the sealing material 39 made of a heat-expandable mat expands, the clean gas passage 38 'of the filter 31 is more hermetically sealed, and good sealing performance is maintained for a long period of time. . The sealing material 39 also absorbs the difference in thermal expansion between the metal casing 32 and the ceramic filter 31. Actually, when this particulate trap device was operated and tested, no leak occurred at all even if the pressure difference between the dust-containing gas side and the clean gas side was 1 kg / cm ² G.

In this particulate trap device, as shown in FIG. 6, as a result of the exhaust gas filling the casing 32, external pressure as indicated by arrow P in the figure is applied to both side surfaces of the filter 31. Therefore, when the high-pressure backwash gas is introduced into the clean gas passage 38 ', the inner pressure due to the backwash gas and the outer pressure indicated by the arrow P cancel each other on both side surfaces of the filter 31, and the effect of preventing the filter 31 from being destroyed is obtained. There is.

On the other hand, as shown in FIG. 7, when the surface of the filter 31 where the dust-containing gas passage 36 ′ is opened is also sealed with the sealing material 58, the portions located on both sides of the filter 31 are wasted spaces 59. Becomes This space 59 is in a low pressure state because no pressure such as exhaust gas is applied thereto. Therefore, when high-pressure gas is introduced into the clean gas passage 38 'during backwashing, no external pressure is applied to both side surfaces of the filter 31 from the outside, so that the filter 31 cannot withstand the internal pressure and is easily broken. .

[Advantages of the Invention] As described above, according to the present invention, the sealing material is provided only on the pair of opposed end faces of the filter in which either one of the dust-containing gas passage and the clean gas passage of the AC filter is opened. With a simple seal structure that applies a seal between the casing and the casing, for example, the work process of assembly work can be reduced to 1/3 that of the conventional method, and even if the casing assembly flange is only one place, dust-containing gas Leakage between the flow channel and the clean gas flow channel can be sufficiently prevented (for example, even if the differential pressure is 1 kg / cm ² G). Further, if the surface of the filter to which the sealing material is applied is directed in the cylinder axis direction of the casing, the casing may have any shape such as a cylindrical shape, an elliptic cylinder shape, and a bellows cylinder shape as well as the rectangular cylinder shape. The filter can be housed and easily sealed.

Further, as a filter, a plurality of holes are formed by penetrating a pair of opposing end faces of the plate-shaped body, and a plurality of the plate-shaped bodies are arranged in parallel so that the traveling directions of the holes are aligned. Another passage through which ribs or spacers are joined to each other through ribs or spacers extending in a direction intersecting the traveling direction of the holes, and the ribs or spacers penetrate between the plate-like bodies in a direction intersecting with the holes. When the filter having the above-mentioned structure is used, it is possible to impart strength enough to withstand the pressure at the time of backwashing for regeneration of the filter.

Furthermore, the filter is made of porous ceramics,
If the sealing material is formed of a heat-expandable mat, it is possible to impart sufficient heat resistance and sealing property when applied to the treatment of high temperature exhaust gas.

Furthermore, if the dust-containing gas flow path and the cleaning gas flow path are each partitioned by a sealing material, a space that does not belong to either of them is formed in the casing, and the pressure balance between this useless space and each flow path space increases, Although an excessive pressure difference may occur in the filter plate, this is not the case in the present invention.

[Brief description of drawings]

FIG. 1 is a perspective view showing a filter housing structure of a particulate trap device according to an embodiment of the present invention, FIG. 2 is a perspective view showing elements of a filter used in the device, and FIG. 3 is a filter used in the device. 4 is a perspective view showing
The figure shows a front view of the same apparatus, and FIG. 5 shows a left side view of the same apparatus.
FIG. 7 is an explanatory view showing the flow of exhaust gas in the casing in the same apparatus, FIG. 7 is an explanatory view showing the flow of exhaust gas in the casing when the four faces of the filter are sealed, and FIG. 8 is a conventional particulate matter. FIG. 9 is a perspective view showing an example of a filter used in a trap device, and FIG. 9 is a perspective view showing another example of a filter used in a conventional particulate trap device. In the figure, 31 is a filter, 32 is a casing, 33 is a plate-like body, 36
Is a hole, 36 'is a dust-containing gas passage, 37 is a rib, 38 is a passage, 38'
Is a clean gas passage, 39 is a sealing material, 40 is a cover plate, 44 and 45 are support portions, 46 is an exhaust gas introduction pipe, and 49 is an exhaust gas discharge pipe.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (56) References JP-A 1-245819 (JP, A) JP-A 62-225221 (JP, A) Actual development Shou 60-118322 (JP, U) “Gas Cleaning at H” IG TEMPERATURES ”pp. 193-213 (THE INSTITUTION ON OF CHEMICAL ENGN EERS SYMPOSIUM SERI ES No. 99, September 1986)

Claims (3)

[Claims] 1. A dust-containing gas passage and a clean gas passage, which are partitioned by a partition wall made of an air-permeable porous material, are formed so as to intersect with each other, and a surface on which the dust-containing gas passage is opened and a clean gas passage are opened. An AC type filter whose surface is not parallel is housed in a casing having a dust-containing gas inlet and a clean gas outlet,
In the particulate trap device configured such that the dust-containing gas inlet communicates with the dust-containing gas passage and the clean gas passage communicates with the clean gas outlet, one of the dust-containing gas passage and the clean gas passage of the filter is A particulate trap device, characterized in that a sealing material is applied only to a pair of opposed end faces of the filter that are open, and a seal is provided between the casing and the casing. 2. The filter has a plurality of holes formed through a pair of opposed end faces of a plate-like body made of a gas-permeable porous material, and the traveling directions of the plate-like bodies are aligned. As described above, the plurality of plate-shaped bodies are arranged in parallel, and the plate-shaped bodies are joined to each other through ribs or spacers extending in a direction intersecting the traveling direction of the holes, and the ribs or spacers are used to connect the plate-shaped bodies between the plate-shaped bodies. The particulate trap device according to claim 1, wherein the particulate trap device is formed by forming another passage penetrating in a direction intersecting with the hole. 3. The filter is formed of porous ceramics, and the sealing material is formed of a heat-expandable mat formed by bonding a heat-expandable material and a ceramic fiber with an organic binder. The particulate trap device according to claim 1 or 2.