JPS5814921A - Structure of purifying exhaust gas and preparation thereof - Google Patents

Abstract

PURPOSE:To provide an exhaust gas purifying structure of which fine particle collecting property and dimensional precisenss are improved, obtained by forming plural irregularily arranged protrusions and plural pores comminucated with adjacent piercing pores to the wall surfaces of piercing pores of a honeycomb structure made of ceramics. CONSTITUTION:Water is added to a fine powder of cordierite, an iron powder and methyl cellulose and the resulting composition is kneaded and extruded from a die to form a honeycomb structure 1 having a predetermined size and, after drying, said honeycomb structure is immersed in a slurry comprising a cordierite fine powder, PVA, a cordierite coarse particle and water and dried after excessive slurry is removed by compressed air. In the next stage, the dried body is baked at about 1,300-1,470 deg.C for about 5hr to obtain a structure A having a ceramic layer comprising plural protrusions 3a and plural holes 5 provided to walls 4 piercing pores 2. In addition, the protrusions 3a of the above described ceramic layer 3 can be formed by using a foaming agent and piercing pores 2 are closed by lids at outlet and inlet sides thereof alternately to make it possible to increase collecting efficiency of a fine powder.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a structure for purifying exhaust gas emitted from OP5WA engines such as automobiles, and a method for manufacturing the structure.

Previously, Sef! −? The honeycomb structure is coated and carries a post-oxidation catalyst, but when this is installed, for example, in the exhaust gas passage, the flow direction of the exhaust gas and the through holes of the honeycomb structure are the same. Since it is oriented in the same direction, the ventilation resistance is small.On the other hand, the interaction with the wall is also small. Therefore, there is a problem that the mass transfer between the exhaust gas and the wall surface is small, and bubbling occurs, resulting in a poor purification rate of the exhaust gas. First, when trying to collect fine particles whose main component is carbon in exhaust gas, the conventional eighty-two cam structure cannot collect most of them.

Furthermore, a ceramic porous material has also been proposed.

Although this company has excellent carbon particle collection efficiency,
The mechanical strength of the percussion peak was weak, and it was extremely difficult to maintain a constant size after firing.

Therefore, the present invention has a large number of irregularly arranged protrusions on the OW surface of the through hole forming the two-cam structure made of ceramic, and has a large number of holes communicating with the adjacent through holes on the wall surface. The purpose of the present invention is to provide an exhaust gas purifying structure that is excellent in collecting fine particles such as carbon and carbon in the exhaust gas and has good dimensional accuracy, and a method for manufacturing the same.

The present invention will be explained in detail below with reference to illustrative embodiments. In No. 111, A is the structure of the present invention, which is composed of a laminate and an i-material as a main component. l is a 6-two cam structure having an outer diameter of 100 II, a height of 12 α, and a wall of 0 through holes 2 having a flat cell μ number of 200 cells lv/inch 10 and a large number of through holes 2. 4 is provided with a semicircular layer 8 having a large number of protrusions 3a, which are arranged in an irregular pattern as shown in detail in FIG. 2 and FIG. First, the wall 4 forming the through hole 2 is provided with a large number of large Ss), allowing gas to freely flow in and out of the adjacent through hole.

The method for manufacturing the v40 structure AO by Moto Sakashita will be explained in detail.

Example 1 Kolifit Hui Powder Kyo (260m-V-under) 150
0g, iron powder (100m IFI/- to 170m?I'-
) 45g,) Chi A/41bCI-190g, water 400a
After adding C and cross-wiring, a green (raw) 6-cam structure 1 of a predetermined size is made by extrusion molding using a known O die.
get. Dry this at sO ℃ for 5 hours. 1500g of powdered flour.

Polyvinyla, A/:l-1&I)OOgs cordiphyte coarse particles (500-1000t/$'') 1ooog.

Water 2500 o oyo J) Ill 9 Cerami! Immerse the above-mentioned 6-cam structure in a liquid solution, and remove excess liquid using compressed air or a centrifuge. After that, 8
Dry at 0°C for 5 hours and bake at 1300-1470°C for S hours. (This is k), many protrusions 3a are already attached to the nine dragons.
A structure A having a large number of holes □ 5 in the layer 3 and the wall 4 is obtained.

In this way, this structure A can be obtained by extrusion molding.
Ekam structure IK protrusion 3a is provided, the structure is rounded, the outer 100 dimensions are the same as a Norris carrier + can be folded, the housing is
Due to the large number of protrusions 3a and the large number of protrusions 3a and 5) standing up, it flows into a certain through hole 2, collides with the protrusion 3&, and flows out from the hole 5). As a result, the gas flow is disturbed and the interaction between the gas and the structure A is increased, and therefore the carbon particulate collection efficiency is extremely improved.

For example, we installed this structure A in the exhaust pipe of a diesel engine and measured the carbon particulate collection efficiency, and found that the average value for one hour was about 604.

1 granite** 62 cam structure used in the example 10 through holes! However, it is preferable that the through hole 2 has a twisted nine structure, for example, a structure in which the six-two cam structure 1 is screwed.

In one actual example, the material of the structure 1 is M%TI% cordierite, but other materials such as alumina, mullite, zirnia, titania, etc. may also be used. However, considering the thermal shock resistance, it is preferable to use a diphyte with a small thermal expansion coefficient O, and if this structure is coated with Kr-AA*om, the carbon fine particle collection efficiency is 2. ~2096
It is confirmed that it increases.

9. The method of adhering ramic coarse particles O also applies to this example Kl.
For example, the wall surface of the 62-cam structure l is cut with a ceramic slab, and after that, the wall surface of the two-cam structure l is cut. Another method is to attach coarse particles.

Moreover, I! which forms the 6-two cam structure 10 through-hole 2! In this example, iron powder is used as the filler material for making holes S in 4, but 9 may also be copper powder or 9 μm powder. Any substance may be used as long as it forms a solid solution and forms a liquid phase at a temperature lower than the melting point of the raw material for the six-two cam structure 10.

Furthermore, the particle size of the additive can be arbitrarily selected depending on the desired large diameter.

Example 2 A nine-run green O honeycomb structure 1 containing iron powder O was obtained in the same manner as in Example 1. Next, 1500 g of cosifit fine powder was added.
, Polypania μco/I/60g.

water 2001) QQ, aluminum image powder (350 mwV
- Soak the fly cam structure 1 in 40g of slurry (very fine), and remove excess nufree from Example 1.
Excretion in the same way.

By drying this at 80°C for 1 hour, it becomes semi-dry, and then by immersing the flycam structure in a double acid solution of 1 tO, 1, hydrogen is generated as a result of the reaction between the aluminum powder and hydrochloric acid. , This causes the cocochine cream to foam. After drying this at 80℃ for 5 hours,
A structure similar to Example 1 was obtained by firing at 00 to 1470°C for 5 hours.

In addition, in this dormitory example, aluminum powder is used as a foaming agent.
A may be made of iron, magnesium, hydrogen hydroxide (in this case foamed with carbon dioxide), etc.
First, in addition to hydrochloric acid, nitric acid, sulfuric acid, cinnic acid, etc. may be used.

Figure 4 shows jJ! of the plane of the present invention. An exemplary structure-B is shown, and this structure-B is a flyom structure 1 forming structure A.
0 Close every other through-hole 2 of the through-holes 20 on one end surface with a flange 6 made of safety material, and close one end [
The K sea is closed and the pre-purchase through hole 2 is opened, and the O through hole 2 is closed.
Since the structure is closed, the gas flows in from one end face and almost all of it passes through the hole 5 in the wall 4 and exits from the other end face. Further, the wall 4 has a large number of protrusions 3a as in Example 1.2.

By using such a structure, the gas flow is disturbed by 20%, and the carbon image particle collection efficiency can be increased by about 10%.

As mentioned above, the present invention is made of ceramic! (K) Exhaust gas It is possible to obtain an exhaust gas purifying structure that has a good collection efficiency of 0Jll of fine particles such as carbon inside and has good dimensional accuracy.

[Brief explanation of drawings]

Fig. 1 is a perspective view showing one embodiment of the present invention, and Fig. 2 is a perspective view showing an embodiment of the present invention.
Figure O-arrow view, jI3 Figure 2 exa view. FIG. 4 is a perspective view showing another embodiment of the present invention. 1.-Fly cam structure, 2-Through hole, 3-Self electric layer, 3a-Protrusion, 4-Wall of hay cam structure. 5-hole, 6-1 inch lid. Representative Patent Attorney Takashi Mabe Figure 1

Claims (1)

[Claims] (1) Through-hole 61 forming a self-contained electric power unit structure
11i An exhaust gas purifying structure characterized by growing protrusions in a K numerous o; F, mat arrangement, and having a large number of holes in the wall surface thereof communicating with adjacent *M holes. Among the through-holes at one end WJ of the eighty-two cam structure, the through-holes are almost uniformly distributed. Patent claim I18 No. 11 [ The structure for purifying exhaust gas as described. (3)ﾆR cam structure structure A 6-two cam structure is formed using raw materials to which eutectic or solid solution substances are added! Shi, scolding bales,
Safe electricity on the through hole 0 wall of the 62 cam structure! A method for manufacturing an exhaust gas purifying structure, characterized by: attaching coarse particles or bubbling on a wall surface to form protrusions, and then drying and firing. .