JP2006272156A - Honeycomb filter - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a honeycomb filter made by joining a plurality of honeycomb structures provided with a large number of flow paths partitioned by partitioning walls in a flow path direction, in which honeycomb structures are not relatively rotationally moved in a cylindrical metallic storing container even if the joint parts of the honeycomb structures are separated, and an increase in pressure loss due to the reduction of the cross sectional area of the flow is therefore suppressed. <P>SOLUTION: An end face on the side to be joined of the plurality of honeycomb structures has a surface practically parallel to the flow paths, and the honeycomb structures are in contact with each other at least at a part of the surface practically parallel to the flow paths. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a ceramic honeycomb filter used for collecting and removing particulate matter in exhaust gas discharged from a combustion apparatus such as a diesel engine or a boiler.

  Exhaust gas emitted from combustion devices such as diesel engines and boilers contains a large amount of particulate matter (particulate matter, hereinafter referred to as “PM”) mainly composed of graphite, which is released into the atmosphere. Doing so will adversely affect the human body and the environment. Therefore, a filter for collecting and removing PM is mounted on these exhaust system parts. FIG. 3 shows an example of a conventional ceramic honeycomb filter (hereinafter referred to as “honeycomb filter”) that collects and removes PM in the exhaust gas of a diesel engine, and (a) is a schematic front view with a part omitted. (B) is a schematic side sectional view. In FIG. 3, a honeycomb filter 30 is made of a porous ceramic, and has a ceramic honeycomb structure (having a large number of flow paths 3 and 4 partitioned by an outer peripheral wall 1 and partition walls 2 orthogonal to each other inside the outer peripheral wall 1. (Hereinafter referred to as “honeycomb structure”) 31 is sealed with sealing portions 5 and 6 alternately at the exhaust gas inflow end surface 7 and the outflow side end surface 8. Although not shown, the outer peripheral wall 1 of the honeycomb structure 31 is gripped so as not to move during use by a gripping member formed of a metal mesh or a ceramic mat, and is disposed in a metal storage container. .

  In the honeycomb filter 30 shown in FIG. 3, the exhaust gas is purified as follows. Exhaust gas (indicated by a dotted arrow) flows in from the flow path 3 opened in the inflow side end face 7. Then, PM contained in the exhaust gas is collected when passing through the partition wall 2, and the purified exhaust gas flows out from the flow path 4 opened in the outflow side end face 8 and is released into the atmosphere. . On the other hand, when the PM trapped in the partition wall 2 exceeds a certain amount, it becomes clogged, and is burned by a burner, an electric heater or the like, and the honeycomb filter 30 is regenerated.

  Incidentally, in recent years, for the purpose of improving the efficiency of collecting PM and the like, an inflow side sealing portion as shown in FIG. 4 has been developed inside a flow channel separated from the inflow side end face of the honeycomb filter. is there. For example, Patent Document 1 proposes a honeycomb filter having the form shown in FIG. 4A and 4B show a honeycomb filter 40 proposed in Patent Document 1, in which FIG. 4A is a schematic front view with a part omitted, FIG. 4B is a schematic side sectional view, and the honeycomb filter 40 is arranged on the inner side of the outer peripheral wall 1a. A honeycomb structure 41A having a large number of flow paths 3a and 4a partitioned by a partition wall 2a is sealed by a sealing portion 5a at the outflow side end face 7b of the flow path 3a. Further, the honeycomb structure 41B having a large number of flow paths 3b and 4b partitioned by the partition walls 2b inside the outer peripheral wall 1b is sealed by the sealing portion 5b on the inflow side end face 8a of the flow path 3b, The outflow side end face 8b of the path 4b is sealed with the sealing portion 6. Then, the outflow side end surface 7b of the honeycomb structure 41A and the inflow side end surface 8a of the honeycomb structure 41B are joined by the sealing portion 5a and the sealing portion 5b, and the honeycomb structure 41A and the honeycomb structure 41B are integrally formed. The filter 40 is used.

JP 2004-251137 A

The honeycomb filter 40 shown in FIG. 4A proposed in Patent Document 1 is generally cylindrical, and as shown in FIG. 5A, a holding member 51 formed of a metal mesh or a ceramic mat or the like. And is accommodated in a cylindrical metal storage container 52. Since such a honeycomb filter has a structure in which the two honeycomb structures 40A and 40B are joined in the flow path direction, the press-fit load when being housed in the metal housing container 52, or the mechanical force when used as a filter. In some cases, cracks occur in the joint J due to vibration or thermal stress, and the honeycomb structure 40A and another honeycomb structure 40B may be separated at the joint J. In such a case, since the outer peripheral walls 1a and 1b are held by the holding member 51, the honeycomb structure 40B may gradually rotate and move relative to the honeycomb structure 40A. For example, as shown in FIG. 5 (b) (arrow section GG (enlarged view) in FIG. 5 (a)), it is relatively rotated (X) in a cylindrical metal storage container 52, The partition wall 2a and the sealing portion 5a of the honeycomb structure 40A straddle the flow path 4b of another honeycomb structure 40B, thereby reducing the cross-sectional area (S) of the flow path 4b and reducing the pressure loss of the honeycomb filter 40. It may increase.

  Accordingly, an object of the present invention is a honeycomb filter in which a plurality of honeycomb structures having a large number of flow paths partitioned by partition walls are joined in the direction of the flow path, and the joints between the honeycomb structures are separated in the unlikely event Even so, it is an object of the present invention to obtain a honeycomb filter that is capable of suppressing an increase in pressure loss due to a reduction in the cross-sectional area of a flow path without relatively rotating in a cylindrical metal storage container.

  The honeycomb filter of the present invention is a honeycomb filter formed by joining a plurality of honeycomb structures having a large number of flow paths partitioned by partition walls in the flow path direction, and an end face on the side where the honeycomb structures are joined is provided. The honeycomb structure has a surface substantially parallel to the flow path, and the honeycomb structures are in contact with each other at least at a part of the surface substantially parallel to the flow path. Here, “substantially parallel surfaces” means that the plurality of honeycomb elements also include surfaces that are not parallel within a range that does not hinder the joining. Further, “contact” means a state in which they are not in contact via a bonding material such as an adhesive but are simply in contact with each other.

  With the above-described configuration, cracks are generated in the joined portion of the honeycomb structure due to press-fitting load when the honeycomb filter is stored in a metal storage container, and mechanical vibration or thermal stress when used as a filter. Even if the structures are separated, the honeycomb structures are engaged with each other in a plane substantially parallel to the flow path, so that they do not rotate and move relatively in the circumferential direction in the cylindrical metal storage container. The increase in pressure loss due to the reduced cross-sectional area of the flow path can be suppressed.

  In the honeycomb filter of the present invention, it is preferable that the honeycomb structure is bonded via a bonding material on at least a part of a surface substantially parallel to the flow path. Joining because the joining area can be increased by joining not only the end faces of the partition walls and the sealing parts as described in Patent Document 1, but also joining the faces substantially parallel to the flow path. The strength is improved, and the possibility that the honeycomb structure is separated is reduced.

  Further, in the honeycomb filter of the present invention, the honeycomb structure includes a plurality of honeycomb elements joined in a direction perpendicular to the flow path, and the end faces of the plurality of honeycomb elements are joined while being shifted in the flow path direction. A surface substantially parallel to the flow path may be formed on the end face of the honeycomb structure. As shown in FIG. 2, when manufacturing honeycomb structures 21A and 21B, a plurality of honeycomb elements divided in the vertical direction with respect to the flow path of the honeycomb structure are joined in parallel to manufacture the honeycomb structures 21A and 21B. By shifting and joining in the flow path direction, the surface can be easily formed on the end surface of the ceramic honeycomb structure.

  The honeycomb filter according to the present invention is a honeycomb filter in which a plurality of honeycomb structures having a large number of flow paths partitioned by partition walls are joined in the flow path direction. Even if the separation is performed, an increase in pressure loss due to a reduction in the cross-sectional area of the flow path can be suppressed without relatively rotating in the cylindrical metal storage container.

Hereinafter, several examples of embodiments of the present invention will be described in detail with reference to the drawings.
(Embodiment 1)
FIG. 1 shows a honeycomb filter according to Embodiment 1, and (a) is a schematic view showing honeycomb structures 11A and 11B before being joined as a honeycomb filter. On the end faces 7b and 8a where the two honeycomb structures 11A and 11B are joined to each other, a face 13 (hereinafter referred to as “meshing face”) substantially parallel to the flow path is formed. (B) is a schematic side sectional view of the honeycomb structure 11A and 11B joined to form a honeycomb filter. As shown in FIGS. 1 (b) and (c), the honeycomb structure is joined by bringing the mating surfaces 13 formed on the joining surfaces of the honeycomb structure 11A and 11B into contact with each other, thereby temporarily joining the honeycomb structures. Even if the portions are separated, the honeycomb structures 11A and 11B do not rotate and move relative to each other, so that the pressure loss due to the reduced cross-sectional area of the flow path does not occur. In addition, the honeycomb structure is bonded not only by bonding the end surfaces of the partition walls and the sealing portions with an adhesive, but also when the meshing surfaces 13 are bonded to each other via a bonding material such as an adhesive, the bonding strength is increased. This can be improved, and the possibility that the honeycomb structures 11A and 11B are separated is reduced.

(Embodiment 2)
FIG. 2 shows a cylindrical honeycomb filter according to Embodiment 2, wherein (a) is a schematic front view of an inflow side end face of the honeycomb filter, and (b) is a cross-sectional view taken along line EE in (a). is there. As shown in FIGS. 2 (a) and 2 (c), the honeycomb structure 21A binds and joins the honeycomb elements Au and Bu at the bonding surface K, and the honeycomb structure 21B has the same Al and Bl. It is formed by binding and joining at the joint surface K. Further, when the honeycomb elements Au and Bu are joined, the meshing surface 13 is formed by joining the outflow side end faces with a distance S shifted as shown in FIG. 2 (c). Similarly, when the honeycomb elements Al and Bl are joined, the meshing surfaces 13 are formed by joining with the distance S shifted. And as shown in FIG.2 (b), even if it joins by contacting so that the meshing surface 13 formed in the joint surface of 11A and 11B of a honeycomb structure may mutually mesh, even if a joined part isolate | separates, Since the honeycomb structures 11A and 11B do not rotate and move relative to each other, there is no increase in pressure loss due to reduction in the cross-sectional area of the flow path. In addition, the honeycomb structure is bonded not only by bonding the end surfaces of the partition walls and the sealing portions with an adhesive, but also when the meshing surfaces 13 are bonded to each other via a bonding material such as an adhesive, the bonding strength is increased. This can be improved, and the possibility that the honeycomb structures 11A and 11B are separated is reduced.

The honeycomb filter 10 shown in FIG. 1 according to Embodiment 1 is obtained as follows. First, kaolin, talc, silica, by adjusting the powder such as alumina, in a mass _{ratio, SiO 2: 48~52%, Al} 2 O 3: 33~37%, MgO: 12~15% and so as cordierite Prepare powdered raw material powder, add graphite as a binder such as methylcellulose, hydroxypropylmethylcellulose, lubricant, pore former, and mix thoroughly in a dry process, then add a specified amount of water, and knead thoroughly Create plasticized ceramic clay. Next, the kneaded clay is extruded using a known extrusion mold, cut into a molded body, and then the molded body is dried, fired, and has a number of channels partitioned by partition walls, A cordierite-like long honeycomb material having a circular cross section and a total length of 320 mm with a diameter after firing of 268 mm is produced.

  Next, a long honeycomb material is cut using a diamond grindstone to obtain a honeycomb structure having a length of 105 mm after cutting and a honeycomb structure having a length of 210 mm after cutting. Next, using a diamond grindstone, one end face of each of the two honeycomb structures is scraped off as shown in FIG. 1A so that the length in the flow path direction becomes 5 mm. The meshing surface 13 is formed, and a honeycomb structure 11A having a length of 105 mm and a honeycomb structure 11B having a length after cutting of 210 mm are obtained.

  Next, after forming the sealing portions 5a, 5b, 6 on the outflow side end surface 7b of the honeycomb structure 11A and the inflow side end surface 8a and the outflow side end surface 8b of the honeycomb structure 11B by a known method, The honeycomb structure 11A and the honeycomb structure 11B are joined as shown in FIG. 1B by applying an adhesive to the mating surfaces 13 of 5a and 5b, whereby the honeycomb filter 10 having a total length of 310 mm is obtained.

The honeycomb filter 20 shown in FIG. 2 according to Embodiment 2 is obtained as follows. First, in the same manner as in Example 1, powders such as kaolin, talc, silica, and alumina were prepared, and by mass ratio, SiO ₂ : 48 to 52%, Al ₂ O ₃ : 33 to 37%, MgO: 12 to 15 %, Prepare a cordierite-forming raw material powder, add a binder such as methylcellulose, hydroxypropylmethylcellulose, lubricant, graphite as a pore former, and mix thoroughly in a dry process, then add a specified amount of water, Thoroughly knead to create a plasticized ceramic clay. Next, the clay is extruded by using an extrusion mold having a fan-shaped cross section, and cut to form a molded body having a fan-shaped cross section. Next, the molded body is dried and fired, has a large number of flow paths partitioned by partition walls, has a cross-section of a sector having a half of a circle, and has a total length of 310 mm with a radius R after firing of 134 mm. Make two long honeycomb materials of light quality.

  Next, one long honeycomb material having a fan-shaped cross section is cut using a diamond grindstone to obtain a honeycomb element Au having a length of 100 mm after cutting and a honeycomb element Al having a length of 205 mm after cutting. Similarly, the remaining long honeycomb material is cut into a honeycomb element Bu having a cut length of 95 mm and a honeycomb element Bl having a cut length of 210 mm. Next, for the honeycomb elements Au and Bu, a sealing portion 5a is formed on the outflow side end surface 7b of the flow path 3a using a known method, and for the honeycomb elements Al and Bl, the flow path 3b A sealing portion 5b and a sealing portion 6 are formed on the inflow side end surface 8a and the outflow side end surface 8b of the flow path 4b, respectively.

  Next, the honeycomb element Au and the honeycomb element Bu are bonded together using an adhesive to produce a honeycomb structure 21A shown in FIG. At this time, since the lengths of the two honeycomb elements Au and Bu in the flow path direction are different by 5 mm, the meshing surface 13 is formed by joining the honeycomb elements Au and Bu so that the inflow side end face 7a is flat. . Similarly, the honeycomb element Al and the honeycomb element Bl are joined using an adhesive to produce a honeycomb structure 21B in which the meshing surface 13 is formed.

  Next, an adhesive is applied to the sealing portions 5a and 5b and the mating surface 13, and the honeycomb structure 21A and the honeycomb structure 21B are joined as shown in FIG. Become.

  In Example 2, the honeycomb structures 21A and 21B were produced by bundling and joining two honeycomb elements each having a cross-sectional shape of a half of a circular shape. Can be divided into more finely divided pieces, for example, four honeycomb elements having a fan-shaped section having a cross-sectional shape of 1/4 can be bound and joined to form each honeycomb structure, and the cross-sectional shape of the honeycomb elements can be other than the fan-shaped shape. It is also possible.

  Further, in Example 2, the honeycomb element 21A is manufactured by bonding the honeycomb element Au and the honeycomb element Bu, and the honeycomb structure 21B is manufactured by bonding the honeycomb element Al and the honeycomb element Bl. The structural bodies 21A and 21B are joined to form the honeycomb filter 20. However, the honeycomb element Au and the honeycomb element Al are joined first, and the honeycomb element Bu and the honeycomb element Bl are joined together, and then both are joined. It can also be 20.

The honeycomb filter concerning Embodiment 1 is shown, (a) is a schematic diagram of the honeycomb structure before joining and it becomes a honeycomb filter, (b) is a side cross-sectional schematic diagram of a honeycomb filter, (c) is (b). It is an enlarged view of F section. The honeycomb filter which concerns on Embodiment 2 is shown, (a) is the schematic diagram of the inflow side end surface of the honey-comb filter which one part omitted, (b) is EE sectional drawing in (a), (c) is joining Then, a schematic diagram of a honeycomb structure before becoming a honeycomb filter, (d) is an enlarged view of an F portion in (b). An example of the conventional honey-comb filter which collects and removes PM in the exhaust gas of a diesel engine is shown, (a) is a schematic diagram of the inflow side end surface which abbreviate | omitted one part, (b) is a side cross-sectional schematic diagram. . The honeycomb filter proposed by patent document 1 is shown, (a) is the schematic diagram of the inflow side end surface which abbreviate | omitted one part, (b) is a side cross-sectional schematic diagram. FIG. 4 is a diagram for explaining relative rotational movement of a honeycomb structure constituting a honeycomb filter of a storage container, (a) is a schematic side sectional view of the honeycomb filter and the storage container, and (b) is a relative view of the honeycomb structure. It is a schematic diagram of arrow GG in (a) after carrying out rotational movement.

Explanation of symbols

10, 20, 30, 40: Ceramic honeycomb filter (honeycomb filter)
11A, 11B, 21A, 21B, 31, 41A, 41B: Ceramic honeycomb structure (honeycomb structure)
13: Surface substantially parallel to the flow path (meshing surface)
DESCRIPTION OF SYMBOLS 1, 1a: Outer peripheral wall 2, 2a, 2b: Partition 3, 3a, 3b, 4, 4a, 4b: Flow path 5, 5a, 5b, 6: Sealing part 7, 7a, 8a: Inflow side end surface 7b, 8 8b: Outflow side end face Au, Bu: Honeycomb element constituting the honeycomb structure upstream of the flow path Al, Bl: Honeycomb element constituting the honeycomb structure downstream of the flow path J: Bonding portion K: Honeycomb element Bonding surface S: Shift dimension

Claims (3)

A honeycomb filter in which a plurality of honeycomb structures having a large number of flow paths partitioned by partition walls are bonded in the flow path direction, and an end surface of the honeycomb structure bonded side is substantially the same as the flow path A honeycomb filter having parallel surfaces, wherein the honeycomb structures are in contact with each other at least at a part of surfaces substantially parallel to the flow path. The honeycomb filter according to claim 1, wherein the honeycomb structure is bonded via a bonding material on at least a part of a surface substantially parallel to the flow path. The honeycomb structure is composed of a plurality of honeycomb elements joined in a direction perpendicular to the flow path, and the flow surfaces are joined to the end faces of the honeycomb structure by joining the end faces of the plurality of honeycomb elements while shifting the end faces in the flow path direction. The honeycomb filter according to claim 1 or 2, wherein a plane substantially parallel to the path is formed.

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