JPH01245819A - Filter element, filter body and filter device - Google Patents

Abstract

PURPOSE:To prevent damage due to bending stress at the time of back washing by forming the inner wall surface of a plurality of holes provided through a planar body of porous material from one end surface thereof to the other, into a specific shape. CONSTITUTION:In case of treating exhaust gases of an Diesel engine, most of particulates in dust-laden gases are captured by the inner wall surface of a plurality of holes 55 of a filter element 51. Attachment and accumulation of the particulates on the inner wall surface of the hole 55 causes an increase in pressure drop of the gases, so that back washing is conducted by blowing off pressurized gases from ejector nozzles on the side of a gas outlet at proper intervals, wherein a considerably high pressure is produced in a passage of clean gases, exerting high pressure repeatedly to the outer wall surfaces 57 of the filter element 51 so as to crush the porous wall. However, because the inner wall surface of the hole 55 has a chevron-shape approaching the side wall 57, bending stress being generated is decreased.

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field] The present invention is mainly used to capture or remove particulates contained in the exhaust gas of diesel engines used in various vehicles, ships, and even industrial equipment. The present invention relates to a plate-shaped filter element suitable for use in, a filter body formed by stacking these filter elements, and a filter device incorporating this filter body.

"Prior art and its problems" Exhaust gas from diesel engines contains a considerable concentration of fine particles whose main component is carbon, causing pollution. For this reason, a number of dust-containing gas passages 27 are formed to collect and remove particulates contained in diesel engine exhaust gas using a filter body. One side of the plate-like body 22 is provided with such ribs 23.24, while the other side of the same plate-like body 22 is provided with ribs 23.24.
Ribs 25,26 are provided which extend in a direction perpendicular to . Ribs 25.26 are essentially similar to ribs 23.24, respectively, except that their directions are orthogonal. In this way, a plurality of stages of the clean gas passages 28, which are open at both ends and whose extension direction is perpendicular to the stages of the dust-containing gas passages 27, are formed alternately.

In this filter body 20, all of the openings of the dust-containing gas passage 27 are directly or indirectly blocked on one end face side among the two end faces in which the dust-containing gas passage 27 is opened, and the diesel engine Introduce exhaust gas. Alternatively, diesel engine exhaust gas is simultaneously introduced inward from both open end faces of the dust-containing gas passage 27. Plate body 2
2 serves as a filter wall, and particulates are collected on the surface of the plate-like body 22 on the dust-containing gas passage 27 side, and the clean gas from which the particulates have been removed passes through the plate-like body 22 and passes through the clean gas passage 28. It flows out of the filter body. Various types of devices have been proposed.

JP-A-56-124417 discloses a filter body 20 made of ceramics as shown in FIG. This filter body 20 has a rectangular parallelepiped outer shape as a whole, and includes a plurality of mutually parallel (eight in FIG. 9) rectangular plate bodies 2.
1.22, a rib 23.25, and a rib 24.26 located in the middle.

The plate-shaped body 21.22, the ribs 23.25, and the ribs 24.26 located in the intermediate portion, or at least the plate-shaped body 22, are made of an air permeable porous thin wall of ceramic having a filter function. The plate-shaped body 21 forms the upper surface and the lower surface of the filter body 20, and the plate-shaped body 22 forms the intermediate surface. Ribs 23 located at the ends and ribs 24 located at the intermediate portions extend parallel to one side of the plate-like bodies 21 between adjacent plate-like bodies 21 and 22 and 22 and 22, respectively. Rib 23.
The upper edge of 24 is in integral contact with the upper plate-shaped body 2I- or 22, and the lower edge of the rib 23.24 is in integral contact with the lower plate-shaped body 22 or 21. As a result, the collected particulates in the diesel engine exhaust gas, which are made of carbonaceous material and have open ends at both ends, are heated and burned off at appropriate time intervals, and the filter body 20 is regenerated. do.

In such prior art, a plate-like body 2 having a filter function
2 is heated to the combustion start temperature of carbonaceous particles, and the collected particles are burned and removed. However, since the plate-like body 22 is repeatedly exposed to high temperatures when burning and removing fine particles, the sintering of the plate-like body progresses, and the initial pore size distribution changes, causing a change in the particle collection operation. The gas passing pressure loss increases, making it difficult to maintain stable performance as a filter body, and the plate body 22 may be eroded due to the high temperature during combustion and removal, resulting in the problem that it becomes virtually impossible to collect fine particles. ing.

Furthermore, in addition to carbonaceous fine particles, diesel engine exhaust gas contains a non-negligible amount (for example, 1 to 5% of the total weight of the fine particles) of nonflammable components, which are simultaneously collected by the filter body. Furthermore, diesel engine exhaust gas contains SOx and NOx components, and these components react with the substances that make up the exhaust gas pipes and the filter body to produce nonflammable solids, which can cause the filter body to deteriorate. deposited inside. Since these non-flammable solids are not removed by combustion, they accumulate in the filter body, causing clogging and reducing the performance of the filter body.

Furthermore, Japanese Patent Application Laid-Open No. 9-225721 discloses a device for removing dust from high-temperature dust-containing gas using a filter tube. This dust removal device uses a plurality of vertically arranged filter tubes with both ends open, and introduces dust-containing gas into the filter tubes from above the filter tubes. The dust whose passage is blocked by the filter tube wall is moved down the filter tube and collected in the dust hopper installed at the bottom of the filter tube, and the clean gas that has passed through the filter tube wall is removed from the side of the filter tube. It is taken out of the filter device. The above-mentioned dust removal device can be understood to be suitable for dust-containing gases that have a large air volume and mainly contain non-combustible dust, such as the dust removal treatment of converter gas in steel plants, and there are no suggestions for application to diesel engine exhaust gas. do not have. Using this method, filter tubes are easy to manufacture, but in order to construct a compact filter body, assembly requires time and effort to temporarily fix a large number of thin filter tubes at intervals. There is a problem in that it is difficult to manufacture a filter body with a large processing capacity because of the process involved.

Therefore, in order to solve these problems, the applicant has already proposed a filter device as shown in FIG.
(Patent application No. 62-232360).

To describe a typical example, using a rectangular parallelepiped filter body 33 that is essentially the same as the filter body shown in FIG.
Casing 31 with openings below and on one side
The filter body 33 is fixed inside through a required sealing member 32, and the filter body 33 is connected to a dust-containing gas passage 34 (indicated by a solid line arrow in the figure) that penetrates from above to below, and intersects with the dust-containing gas passage. A clean gas passage 35 (indicated by a broken line arrow in the figure), which is closed at one end and opened laterally at the other end, is defined by a plate-shaped body 22 made of a porous breathable material.

An inlet pipe 37 for diesel engine exhaust gas is provided in the upper part of the casing 31 . An exhaust gas outlet pipe 38 is connected to the filter body of the casing 31 on the side where the clean gas passage 35 opens. The exhaust gas outlet pipe 38 includes a throat portion 39 having a reduced diameter, and its upstream and downstream portions are gradually expanded in diameter. An ejector nozzle 40 for injecting pressurized gas for backwashing operation is provided near the downstream end of the throat portion 39 and opens toward the upstream side of the filter body. A particulate receiver part 41 is provided below the casing 31. The particulate receiver 41 has a tray 42, a filter plate 43 with an electric resistance heater 46, an ash outlet 44 with a lid 47 that can be opened and closed and is normally closed, and a gas outlet 45.

The filter plate 43 is fitted into the bottom of the tray 42 by hollowing it out, and the tray 42 and the filter plate 43 collectively surround the lower open end of the dust-containing gas passage 34 of the filter body 33. The ash extraction port 44 opens at the bottom of the tray 42, and a gas outlet 45 is provided below the filter plate 43. The ventilation resistance of the filter plate 43 is such that less than 20%, particularly about 0.5 to 5% of the total amount of exhaust gas introduced from the exhaust gas introduction pipe 37 passes through the filter plate 43.
The remainder is selected so as to pass through the plate-like body 22 of the filter body 33 and be taken out to the exhaust gas outlet pipe 38.

Diesel engine exhaust gas is introduced into the dust-containing gas passage 34 of the filter body 33 from its upper open end via the introduction pipe 37. Most of the gas components of the exhaust gas pass through the porous plate-shaped body 22 and become clean gas, and flow out into the exhaust gas outlet pipe 38 via the clean gas passage 35. At the same time, some of the particles are captured and deposited on the wall surface on the side of the dust-containing gas passage 34, and at the same time, some of the particles flow out from the lower opening end of the dust-containing gas passage 34 to the particulate receiver section 41 together with a part of the exhaust gas. The gas components of the exhaust gas that flowed into the particulate receiver part 41 pass through the filter plate 43 and reach the gas outlet 45.
Almost all of the particulates in the exhaust gas are captured by the filter plate 43 and deposited on the inner surface of the filter plate 43.

After continuing this dust collection operation for an appropriate time, the ejector nozzle 4
Pressurized gas, especially pressurized air, for example 0.1-
Perform backwashing operation by spraying water for about 1 second. The injected gas attracts gas around the nozzle 40 , and gas in an amount several times the amount of pressurized gas injected becomes a pulse flow, enters the clean gas passage 35 , and passes through the porous plate-shaped body 22 . The dust-containing gas flows into the dust-containing gas passage 34. At this time, the particulates that had adhered and accumulated on the wall surface on the side of the dust-containing gas passage 34 fall off, and part of them floats in the part 41 of the dust-containing gas passage, but many of them fall and enter the part 41 where the particulates are receptacle. .The particulate receiver part 41 has a filter plate 43.
Almost all of the falling particles are deposited on the inner surface of the filter plate 43 as the gas flows through the filter plate 43 .

In this way, the particulates caught on the wall surface on the side of the dust-containing gas passage 34 during the dust collection operation are transferred to the inner surface of the filter plate 43 during the backwashing operation, and the filter function of the filter body 33 is regenerated. The fine particles on the inner surface of the filter plate 43 are heated by the electric resistance heater 46 and burned and removed.

If the filter body is used for a relatively long period of time, the particulate bag will
In particular, since non-flammable particulates, ash, etc. accumulate on the inner surface of the filter plate 43, the lid 47 is opened to allow these particulates and ash to fall naturally, or they are forcibly discharged using an appropriate scraping mechanism. .

However, in this filter device, when the gas becomes a pulse flow and flows into the clean gas passage 35 during repeated backwash operations, the inside of the clean gas passage 35 momentarily becomes under a considerably high pressure, for example, 0.3 to 0.4 The problem is that when a gas pressure of about 100 kg/cm" is applied, bending stress is repeatedly applied to the plate-shaped body 22 that partitions the clean gas passage 35 and the dust-containing gas passage 34 of the filter body 33, and the plate-shaped body 22 is often damaged. There was a point.

Further, the conventional filter body shown in FIG. 9 has a very complicated overall structure, which causes problems in that it takes time and effort to manufacture and has a high incidence of defective products.

``Object of the Invention'' In view of the problems of the prior art described above, the object of the present invention is to provide a filter element having a structure that can sufficiently withstand the bending stress repeatedly generated by the pressure of the backwash airflow during backwashing of the filter body. To provide a filter body that is easy to manufacture and has a high yield by laminating the plate-shaped filter elements to form a filter body.
Another object of the present invention is to provide a filter device using this filter body.

"Structure of the Invention" A filter element according to the present invention has a pair of opposing end surfaces of a plate-like body made of an air-permeable porous material, and a plurality of holes are formed through the plate-like body from one end face to the other end face. This is a plate-shaped filter element characterized in that the inner wall surfaces of the plurality of holes are respectively mountain-shaped toward adjacent side wall surfaces.

In a preferred embodiment of the present invention, the side wall surface of the plate-like body is quadrilateral, and furthermore, the shape of the cross section of the plurality of holes cut along a plane perpendicular to the center line of the plurality of holes is circular. ,
This is a plate-shaped filter element selected from an ellipse or a polygon larger than a square.

In another preferred embodiment of the present invention, center lines of the plurality of holes are generally straight lines and are generally parallel to each other, and further, the plurality of holes are opened generally in a line on the opposing end surfaces. It is a plate-shaped filter element.

In yet another preferred embodiment of the present invention, the plate-shaped body is provided with a rib that extends along the edge of each of the opposing end faces of the plate-shaped body to protrude and extend toward the side wall surface adjacent to the end face. It is a filter element.

In another preferred embodiment of the present invention, the material constituting the plate-like body is ceramic, and the plate-like body is made of an air-permeable porous material such as sintered metal or porous glass depending on the type of dust-containing gas to be treated. This is a filter element.

The filter body according to the present invention has a pair of opposing end surfaces of a plate-like body made of an air-permeable porous material, and a plurality of holes are formed through the plate-like body from one end face to the other end face,
A plate-shaped filter element in which the inner wall surfaces of the plurality of holes each form a mountain shape toward the side wall surface of the plate-shaped body adjacent to each other,
A plurality of filter elements are laminated in parallel so that the end surfaces are aligned, and the plurality of holes are separate passages defined by the porous walls of the plate-like body between the filter elements, and the filter element is particularly is a filter body configured such that the another passage is open on both sides where a pair of adjacent end faces are different from the pair of opposing end faces where the plurality of holes of the plate-like body are open.

In a preferred embodiment of the filter body of the present invention, a plurality of plate-shaped filter elements are laminated in parallel, each having a rib that extends along the edges of the pair of opposing end faces and protrudes toward the side wall surface adjacent to the end faces. The plurality of holes are defined by the ribs between the filter elements, and the plurality of holes constitute another passage having a width approximately equal to the protruding width of the ribs, which is defined by a porous wall of the plate-like body. .

In another preferred embodiment of the filter body of the present invention, the filter elements are laminated with a spacer interposed between them, and the plurality of holes are defined by the spacer by the porous wall of the plate-like body. a filter body defining another passageway of width approximately equal to the thickness of the filter body;

In the filter device of the present invention, a plurality of holes are formed through a pair of opposing end faces of a plate-like body made of an air-permeable porous material from one end face to the other end face, penetrating the plate-like body,
A plate-shaped filter element in which the inner wall surfaces of the plurality of holes each form a mountain shape toward the side wall surface of the plate-shaped body adjacent to each other,
A plurality of filter elements are stacked in parallel so that the end surfaces are aligned, and the plurality of pores constitute a separate passage defined by the porous wall of the plate-like body between the filter elements,
The filter body is configured such that the other passage is open on both sides of a pair of adjacent end faces that are different from the pair of opposing end faces where the plurality of holes of the plate-like body are open,
This is a filter device in which the filter body is fixed and housed via a sealing material in a metal casing provided with an inlet for dust-containing gas, an outlet for clean gas, and an outlet for powder sulfur.

A preferred embodiment of the filter device of the present invention is a filter device in which the filter body is housed in a metal casing so as to be pressed against it by a cushioning material and/or a spring material.

Still another preferred embodiment of the filter device of the present invention is a filter device in which regeneration is performed by a backwashing operation in which compressed gas, particularly compressed air, is blown into the clean gas outlet passage.

In another preferred embodiment of the filter device of the present invention, a passage for dust-containing gas is provided inside the plurality of holes of the filter body, and the other passage provided between the filter elements is used as a passage for clean gas. It is a filter device.

Yet another preferred embodiment of the filter device of the present invention is a filter device in which the dust-containing gas to be treated is exhaust gas from a day-cell engine.

In the plate-shaped filter element of the present invention, a filter body can be constituted by just one plate, but in general, a plurality of plates are arranged in parallel at predetermined intervals, and ribs and/or spacers are provided in each gap. By arranging and stacking,
A filter body having a desired filter area can be easily constructed.

That is, in the filter device of the present invention, a plurality of holes provided so as to pass through a plate-shaped filter element made of an air-permeable porous material are used as dust-containing gas passages, and gaps provided between the stacked filter elements are used as dust-containing gas passages. is used as a clean gas passage, and when the dust-containing gas is fed into the plurality of holes, the fine particles in the dust-containing gas are captured on the inner wall surface of the plurality of holes in the plate-shaped body, and the gas components pass through the porous wall. Then, the gas becomes a clean gas and flows out into the clean gas passage formed between the plate-like bodies.

The fine particles deposited on the inner wall surfaces of the plurality of holes are removed by a backwashing operation in which a backwash air flow is sent to the clean gas passage side formed between the plate-like bodies. Peel off the top and regenerate the filter body.

Gas pressure during backwashing is applied toward the inside of the plurality of holes from the side wall surface of the plate-like body where the clean gas passage is located.

At this time, in the filter element of the present invention, the inner wall surfaces of the plurality of pores each form a mountain shape toward the adjacent side wall surface, so that the flat porous wall that does not have a mountain shape in the prior art Because large bending stress does not occur on the porous wall, it can withstand gas pressure during backwashing operations.
Damage to the porous wall, which is the filter wall, hardly occurs.

The side wall surfaces in the filter element of the present invention are generally flat, and are a pair of wider planes among the outer surfaces of the plate-shaped body, and are generally parallel to each other. The plurality of holes are located between the m pair of planes and form a plurality of long holes penetrating the plate-like body from one end surface to the other end surface.

The pore size of the plate-shaped filter element of the present invention can vary depending on the intended use, but
Since there is a demand for compactness for collecting particulates from diesel engine exhaust gas, it is better to make the inner diameter of the pores small (to increase the filter area per volume. However, if it is too small, there is a risk of clogging by particulates. Therefore, it is preferable that the filter element has an inner diameter of about 3 to 10 mm and a thickness of about 6 to 30 mm.

For example, when a relatively large plate-shaped filter element can be used for applications such as dust removal treatment of dust-containing gas from a fixed source, the thickness of the filter element may be 1.5 cm with holes having an inner diameter of 1 to 10 cm, for example. It can be about 5 to 15 cm, but if the weight of the plate-shaped filter elements is too large, it becomes difficult to handle manually, so it is preferable that the weight of the filter elements is 15 kg or less. .

Further, since the plate-shaped filter element of the present invention has a simple structure, it can be easily manufactured by, for example, extrusion molding, casting molding, etc., and the occurrence of defective products during manufacturing can be reduced. Furthermore, by holding or joining together a plurality of filter elements stacked in parallel via ribs or spacers, a filter body having an arbitrary filter area can be provided.

In the filter body of the present invention, it is preferable that the width of the other passage, which is normally a clean gas passage, formed between the filter elements stacked in parallel to each other increases the filter area per volume of the filter body. The narrower the hole, the better, and preferably 1/2 or less of the inner diameter of the hole passing through the filter element. However, if the surface precision of the side wall surface is not good (if not, it will not be possible to make it narrow, and if it is too narrow, there is a risk that the backwashing gas will not be effective during backwashing because the resistance to feeding it will increase, so it is preferably 1.5 mm or more.

Specific examples of the present invention will be described below with reference to the drawings.

FIG. 1 shows an example of a plate-shaped filter element according to the present invention. This plate-shaped filter element 51 is
It consists of a plate-like body 52 made of an air permeable porous material.

As the material of the plate-like body, for example, ceramics, sintered metal, porous glass, etc. can be used, and among these, cordierite, β-subodumene, aluminum titanate, which has excellent corrosion resistance, heat resistance, and thermal shock resistance are used. Ceramics such as zircon, mullite, silicon carbide, and silicon nitride are particularly preferred because they can be used to treat various dust-containing gases.

A plurality of holes 55 are formed through the plate-like body from one end face 53 to the other end face 54 of a pair of opposing end faces of the plate-like body.

In this example, as a preferable example, a plurality of holes 55 are opened in a row on both of the pair of end faces, but as long as the objective effect of the present invention is not impaired, a plurality of holes 55 may be provided in the plate-like body 52.
5 may be arranged in two or three rows.

FIG. 4 is a cross-sectional view of the filter element taken along a plane perpendicular to the center line of the plurality of holes extending parallel to each other.
Each of the inner wall surfaces 56 is mountain-shaped toward the adjacent side wall surface 57. To explain this in more detail, in the distance between the inner wall surface 56 and the side wall surface 57 of the plurality of holes, let the distance at the center be a, and the distances at both ends be s and c.
The hole has a cross-sectional shape such that b > a and c > a.

In this example, holes having a circular cross section (round holes) are used as the plurality of holes 55, but the above b> a, c
If >a is satisfied, a hole with an elliptical cross section as shown in Figure 5 (elliptical hole), a hole with a square cross section as shown in Figure 6, or a hole with a square cross section as shown in Figures 7 and 8 can be formed. Holes with a hexagonal cross section can also be used. However, when the negative part of the inner wall surface 56 of the hole is parallel to the side wall surface 57 as shown in FIG. 8, it is important not to make the length d of this part too large.

Returning to FIG. 1 again, a projection 158 extends toward the adjacent side wall surface 57 along the edge of the end surface 53,54 of the plate-shaped body 52 where the plurality of holes 55 are opened. Although the ribs 58 are not essential to the present invention, they facilitate assembly when plate-shaped filter elements are stacked to form a filter body, as will be described later.

In this example, each rib 58 is formed to protrude on the same side wall surface of the plate-like body 52, but the protruding force and direction of one rib 58 and the other rib 58 are different. may be located on opposite sides of the plate-like body 52, or may be formed in a T-shape or a single-shape so as to protrude from both sides of the plate-like body 52.

Further, in this example, the ribs 58 are formed only on the edges of the pair of opposing end surfaces of the plate-like body 52, but the ribs 58.58
There may be any number of ribs intermediate and parallel to the ribs. In this case, the rib closes one exit of the other passage formed between the plate-like bodies. Furthermore, a rib orthogonal to the rib 58 may be provided along the edge of one of the remaining end faces, which is different from the pair of end faces of the plate-shaped body 52.

2 and 3 show a filter body 61 constructed using filter elements 51. FIG. This filter body 61
In this case, a plurality of filter elements 51 are stacked in parallel, and between the filter elements, the plurality of holes constitute another passage defined by the porous wall of the plate-like body.

The filter elements 51 are stacked so that the end faces where the plurality of holes 55 open are aligned and the ribs 58 face in the same direction.

The protruding end surface of the rib 58 and the part where it contacts the side wall surface 57 of the adjacent filter element 51 are bonded together using, for example, a heat-resistant adhesive, or pressed with a cushioning material or gasket sandwiched between them. means of tightening, etc.
Alternatively, they are joined at least in a dust-tight manner by means such as integral sintering.

Thus, in the gaps between the filter elements 51,
A clean gas passage 62 defined by the rib 58 and the side wall surface 57 is formed to open on a side different from the opening surface of the plurality of holes 55 .

This filter body 61 can be used, for example, as the filter body 33 of a filter device as shown in FIG. That is, when dust-containing gas such as diesel engine exhaust gas is introduced through one opening of the plurality of holes 55,
The fine particles are captured on the inner wall surfaces of the plurality of pores, and the cleaned gas passes through the wall of the porous plate-like body 52 and is taken out from the clean gas passage 62.

Most of the particulates contained in the dust-containing gas are captured on the inner wall surfaces of the plurality of holes 55, a part of which is directly attached to the inner wall surface, and the remaining part is captured from the other opening of the plurality of holes 55, for example. The particulate matter in FIG. 10 falls or flows out into the part 41 and is collected.

When fine particles adhere to and accumulate on the inner wall surfaces of the plurality of holes 55, the pressure loss of the gas increases. Therefore, as shown in FIG. Backwash is performed by blowing out gas. During this backwashing, the pressurized gas ejected from the nozzle entrains surrounding gas and becomes a pulsed flow that is blown into the clean gas passage 62. As a result, the inside of the clean gas passage 62 momentarily becomes considerably high pressure, and as shown in FIG. 4, a high pressure P is repeatedly applied to the outer wall surface 57 of the filter element 51. This pressure P acts to crush the porous wall between the plurality of holes 55 and the side wall surface 57. However, in the plate-shaped filter element of the present invention, the inner wall surface 5 of the plurality of holes 55
6 are each shaped like a mountain toward the adjacent side wall surface 57, so that the generation of bending stress against the above-mentioned pressure P is reduced in terms of structural mechanics, and the filter wall Damage to the porous wall can be prevented.

In addition, in the filter body 61 shown in FIG. 2, a spacer or the like separate from the filter element 51 can be used in place of the rib 58, and in that case, it is not necessary to provide the rib 58. The filter element 51 can be made into a flat plate shape that can be manufactured efficiently by extrusion molding.

Furthermore, a plurality of holes 55 passing through the plate-like body include the ribs 58.
The filter element 5 is formed so as to protrude toward the side wall surface adjacent to one edge of the end surface parallel to the center line direction of the filter element 5.
1 are stacked, the clean gas passage 62 may open at the same end surface as the plurality of holes 55, but in that case,
A sealing means is required to separate the clean gas flow path and the dust-containing gas flow path in the end face.

In the plate-shaped filter element of the present invention, it is preferable that the inside of the plurality of holes 55 be used as a dust-containing gas passage, and the passage between the side wall surfaces 57 be used as a clean gas passage, but there is a problem of damage due to pressure during backwashing. If there is no such hole, the inside of the plurality of holes 55 can be used as a clean gas passage, and the side of the side wall surface 57 can be used as a dust-containing gas passage.

A preferred example of the filter device of the present invention has the configuration shown in FIG.
This proposal differs from the proposal shown in 1 in terms of the structure of the filter body.

Embodiment of the Invention As an example of the present invention, a filter body having the structure shown in FIG. 2 was manufactured as a prototype, and a filter body having the structure shown in FIG. 10 was assembled as a prototype. Further, for comparison, a filter device having the configuration shown in FIG. 10 was fabricated as a prototype by incorporating the filter body shown in FIG. 9. The specifications, test conditions, and test results of the filter element and filter body tested are shown below.

Plate-shaped filter element (-example) material of the present invention
Cordierite molding method Cast molding porosity approx. 34% Average pore diameter
; Approximately 22 μm length x width x thickness;
240 x 224 x 15 mm hole diameter
7mm hole pitch; 1
0 n+m rib height 2.8
mm Filter body of the present invention (example) One block is made by laminating 20 of the filter elements, and three blocks are stacked one on top of the other so as to connect the other passages formed between the filter elements,
It was used as a filter body for testing.

However, the inside of the circular hole of the filter element was used as a dust-containing gas passage, and the other passage between the filter elements was used as a clean gas passage.

Clean gas passage width: Approx. 3, Omm Effective filter area: Approx. 7.2 Filter body material for comparison: Cordierite Molding method
Integral casting porosity approx. 34
% Average pore diameter - Approximately 23μm Length x width x height; 700 x 610 x 350
nm Exhaust gas flow path width; 5 mm Clean gas flow path width: 5 mm Effective filter area;
7.1 Go test conditions Engine used; Displacement 6.7j2. Direct injection type% type Exhaust gas: 2900rpm x 130ps
Operates at Exhaust gas temperature: 550℃ Exhaust gas flow rate: 43ON/hr Backwashing conditions Air source pressure: 6.0kg7cm'' Backwashing time: O, 1sec Backwashing interval: 300sec Ejector nozzle: Diameter: 25mm ; 85NI 2/time test result Average filter pressure drop during use Example: Approximately 1200 mmAq Comparative example: Approximately 1200 mmAq However, a decrease was observed after approximately 20 hours.

Particulate concentration in clean gas Example: Approximately 3 mg/Nm3 No change after 50 hours.

Comparative example: Approximately 3 mg/Nm” However, after about 20 hours It started to increase after 30 hours. Approximately 120 mg/Nm for connection It became. this is a filter Damage (cracks) occur on the body. This is because

Other results 5. In addition, in the plate-shaped filter element of the present invention, the thickness of the wall between the inner wall surface of the plurality of holes and the side wall surface of the plate-shaped body differs depending on the region, so there is a difference in ventilation resistance. There was a concern that the inner wall surface of the hole would not be used uniformly as a filter surface, but since the pressure loss during dust collection operation is largely dependent on the layer of fine particles captured on the filter surface, it is not practical. It was confirmed that it can be used without any problems.

"Effects and Effects of the Invention" As explained above, if a plate-shaped filter element made of a plate-shaped body made of an air-permeable porous material of the present invention is penetrated with a plurality of holes, it is possible to The filter body can be assembled by simply stacking them in parallel with a gap of a certain width, so it is possible to construct a filter body with any desired filter area, and at the same time, it is easy to manufacture, and the production of defective products is reduced. .

Furthermore, as shown in the results of comparison with the embodiments of the invention, even if the clean gas passage becomes high pressure due to the backwash air flow and high pressure acts on the wall surface, the plurality of filter elements constituting the dust-containing gas passage Since the inner wall shape of the pores is mountain-shaped toward the side wall surface, it is possible to prevent damage to the porous wall that is the filter wall, that is, damage to the filter element. When a filter device using a filter body constructed as shown in FIG.

Although the plate-shaped filter element, filter body, and filter device according to the present invention are suitable for removing particulates from diesel engine exhaust gas, they can also be used for removing dust from other dust-containing gases, such as blast furnaces, converters, and coke in steel plants. It can be used to remove dust from dust-containing gas generated in furnaces, coal gasification equipment, nuclear waste combustion treatment equipment, fluidized catalytic cracking equipment, fluidized bed boilers, etc.

Furthermore, by using the compact filter device of the present invention with a large filter area per volume, dust can be removed with almost no cooling of the dust-containing gas, which is a feature that has not been carried out conventionally due to the presence of dust. Heat recovery from high-temperature dust-containing gas, which was previously not available, opens the door for application in many cases, including small-capacity equipment, and also from the point of view of energy conservation, and because dust can be recovered in a dry state, The industrial value of the recovered dust is also great in terms of its effective use.

[Brief explanation of the drawing]

FIG. 1 is a perspective view showing an embodiment of a plate-shaped filter element according to the present invention, FIG. 2 is a perspective view showing a filter body constructed using the filter element, and FIG. 3 is a partial cross-sectional view of the filter body. 4 is a partial cross-sectional view showing the pressure state applied to the filter element during backwashing operation, and FIGS. 5, 6, 7, and 8 are views of the plate-shaped filter element according to the present invention. FIG. 9 is a perspective view showing a conventional filter body, and FIG. 10 is an example of a filter device using a filter body of the type shown in FIGS. 2 and 9. FIG.

Claims (17)

[Claims] (1) A plurality of holes are formed passing through the plate-like body from one end face to the other end face of a pair of opposing end faces of a plate-like body made of an air-permeable porous material, and the plurality of holes A plate-shaped filter element characterized in that the inner wall surfaces of the filter elements each form a mountain shape toward the side wall surfaces of the adjacent plate-shaped bodies. (2) The plate-shaped filter element according to claim 1, wherein the side wall surface of the plate-shaped body is quadrilateral. (3) In claim 1 or 2, the shape of the cross section of the plurality of holes cut along a plane perpendicular to the center line of the plurality of holes is circular;
A plate-shaped filter element selected from an ellipse or a polygon larger than a square. (4) A plate-shaped filter element according to any one of claims 1 to 3, wherein center lines of the plurality of holes are generally straight lines and are generally parallel to each other. (5) A plate-shaped filter element according to any one of claims 1 to 4, wherein the plurality of holes are opened on both sides of the opposing end surfaces, respectively, and are generally aligned in a line. (6) In any one of claims 1 to 5, a rib is formed along an edge of each of the opposing end faces of the plate-shaped body to protrude and extend toward a side wall surface adjacent to the end face. A plate-shaped filter element. (7) A plate-shaped filter element according to any one of claims 1 to 6, which is made of an air-permeable porous material, in which the material constituting the plate-shaped body is ceramic. (8) A plate-shaped filter element according to any one of claims 1 to 6, in which the material constituting the plate-shaped body is made of an air-permeable porous material, which is either sintered metal or porous glass. (9) A plurality of holes are formed passing through the plate-like body from one end face to the other end face of a pair of opposing end faces of a plate-like body made of an air-permeable porous material, and the plurality of holes A plurality of plate-shaped filter elements each having a mountain shape toward the side wall surface of the plate-shaped body whose inner wall surfaces are close to each other are stacked in parallel so that the end surfaces are aligned, and the plurality of plate filter elements are stacked in parallel with each other with the end surfaces aligned. The pores of the filter body constitute another passage defined by the porous wall of the plate-like body. (10) In claim 9, the another passage is configured to open on both sides of a pair of adjacent end surfaces that are different from the pair of opposing end surfaces in which the plurality of holes of the plate-like body are open. filter body. (11) In claim 10, a plurality of plate-shaped filter elements each having a rib formed along the edge of the pair of opposing end surfaces of the plate-shaped body to protrude and extend toward the side wall surface adjacent to the end surface. The filter elements are laminated in parallel, and the plurality of holes constitute another passage having a width approximately equal to the protruding width of the ribs, which is defined by the porous wall of the plate-shaped body, between the filter elements by the ribs. A filter body characterized by: (12) In claim 10 or 11, the filter elements are laminated with a spacer interposed between them, and the plurality of holes are defined by the thickness of the spacer defined by the porous wall of the plate-like body. A filter body characterized in that it defines another passageway of width approximately equal to . (13) A plurality of holes are formed passing through the plate-like body from one end face to the other end face of a pair of opposing end faces of a plate-like body made of an air-permeable porous material, and each of the plurality of holes A plurality of plate-shaped filter elements each having a mountain shape toward the side wall surface of the plate-shaped body whose inner wall surfaces are close to each other are stacked in parallel so that the end surfaces are aligned, and the plurality of holes are formed between the filter elements. constitutes another passage defined by the porous wall of the plate-like body, and the another passage is a pair of adjacent end faces different from the pair of opposing end faces in which the plurality of holes of the plate-like body are open. A filter body is configured to open on both sides with end faces, and the filter body is fixed via a sealing material to a metal casing provided with an inlet for dust-containing gas, an outlet for clean gas, and an outlet for dust. The filter device was installed in this way. (14) The filter device according to claim 13, wherein the filter body is housed in a metal casing so as to be pressed by a cushioning material and/or a spring material. (15) The filter device according to claim 13 or 14, wherein the filter device is regenerated by a backwashing operation in which compressed gas is blown into the outlet passage side of the clean gas. (16) The filter device according to claim 15, wherein the inside of the plurality of holes of the filter body is used as a passage for dust-containing gas, and the other passage provided between the filter elements is used as a passage for clean gas. (17) The filter device according to any one of claims 13 to 16, wherein the dust-containing gas to be treated is diesel engine exhaust gas.