JPH09323132A - Structure of metallic catalyst carrier - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve the performance of a catalyst by improving the contacting property between waste gas and a catalyst coating layer while improving temp. rising characteristics by reducing heat mass in a metallic catalyst carrier. SOLUTION: By forming the parts where a high-wave plate 16 and low-wave plate 17 are overlapped in both end parts of the metallic catalist carrier, forming the part where either of the high-wave plate 16 or the low-wave plate 17, the low-wave plate 17, for example is removed, the other, i.e., only the high-wave plate 16 is present in the middle part between both end parts of the metallic catalyst carrier and making the wave pitches of bothwave plates 16, 17 in the same pitch, the high-wave plate 16 is positioned with the low-wave plate 17, the wave pitch is uniformed over the whole of the high-wave plate 16 and, furthermore, the heat mass is reduced.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a metal catalyst carrier incorporated in a catalytic converter device or the like which is interposed in an exhaust passage of an engine to purify exhaust gas, and relates to a technique for improving the performance of the metal catalyst carrier.

[0002]

2. Description of the Related Art Conventionally, as a catalytic converter device for purifying exhaust gas which is interposed in an exhaust passage of an engine and purifies substances such as CO, HC, NOx in exhaust gas, a metal catalyst carrier carrying a catalyst is built in a shell. There is something I prepared for. As the metal catalyst carrier, there is a metal catalyst carrier having a structure in which a corrugated sheet made of metal foil and a flat plate are alternately stacked.

In this case, one formed simply by laminating,
In some cases, the whole is formed into a roll shape by laminating and winding. By the way, conventionally, in such a metal catalyst carrier, for the purpose of shortening the heat-up time of the catalyst carrier by accelerating the temperature rising rate by reducing the heat mass, the portion where the corrugated plate and the flat plate are superposed on both ends. It is known that the flat plate is removed and a portion where only the corrugated plate is present is provided in the intermediate portion between the both end portions (see Japanese Patent Laid-Open No. 6-269683).

[0004]

However, in such a conventional metal catalyst carrier, since the flat plate is laminated with the corrugated plate only at both ends thereof, the following problems occur. Occurs. That is, when the flat plate is arranged together with the corrugated plates only at both ends of the metal catalyst carrier, the gap between the adjacent corrugated plates is partially narrowed when the pitch shift of each corrugated plate occurs in the middle part. On the contrary, a part where the interval becomes wide partially occurs.

This will be described with reference to FIG.
This is a case where the corrugated sheets 1 are properly arranged without any pitch deviation. On the other hand, FIGS. 7 and 8 show the case where the respective corrugated plates 1 are arranged with a pitch shift therebetween. In this way, when a portion where the space between the adjacent corrugated plates 1 is narrowed occurs, when the corrugated plate 1 is coated with the catalyst coating material 2, the space between the adjacent corrugated plates with the catalyst coating material 2 is reduced. It accumulates in a narrow part and clogging occurs in this part.

Since the catalyst coating material 2 in such a clogged portion is not provided for contact with exhaust gas, the corrugated plate surface area (catalyst coating layer surface area) in contact with exhaust gas is substantially reduced and the catalyst is The coating material 2 is also wasted. On the other hand, when a part where the interval between the adjacent corrugated plates 1 becomes wide partially occurs, the exhaust gas and the catalyst coating layer are not sufficiently contacted with each other in this part, which leads to deterioration of the conversion efficiency of the catalyst. .

In view of the conventional problems as described above, the present invention improves the temperature rising characteristics by reducing the heat mass by improving the shape of the metal plates to be laminated and the arrangement structure in the metal catalyst carrier. It is an object to improve the catalytic performance by improving the contact property between the exhaust gas and the catalyst coating layer.

[0008]

Therefore, in the invention according to claim 1, a large corrugated metal plate having a large wave height and a small corrugated metal plate having a small wave height, which are bent in a wave shape in one direction, are alternately stacked. A metal catalyst carrier having a structure laminated together,
The wave pitches of the large corrugated plate and the small corrugated plate are formed at substantially the same pitch, and a portion where either one of the large corrugated plate and the small corrugated plate is removed is provided in part.

In the invention according to claim 1, since the large wave plate is positioned by the small wave plate, the wave pitch of the large wave plate does not shift, and the wave pitch is uniform over the entire large wave plate. In the invention according to claim 2, the portion where the large corrugated plate and the small corrugated plate are overlapped is at both ends, the portion where either one of the large corrugated plate and the small corrugated plate is removed and only the other is present, between the both ends, respectively. It is configured to have.

In the invention according to claim 2, the large corrugated plate is positioned by the small corrugated plate at both ends. In addition, in the portion where one corrugated plate is removed, the interval between the other corrugated plates adjacent to each other can be made narrower rather than partially. In the invention according to claim 3, by setting the small corrugated plate to the maximum possible wave height, the interval between the large corrugated plates on both sides of the small corrugated plate is minimized.

In the invention according to the third aspect, it is possible to effectively increase the surface area of the corrugated sheet that is in contact with the exhaust gas.
The invention according to claim 4 is a metal catalyst carrier having a structure in which a large corrugated metal plate having a large wave height and a small corrugated metal plate having a small wave height, which are each bent in a wavy shape in one direction, are alternately laminated. The positioning of each large corrugated plate is performed by the small corrugated plate, and the heat mass is reduced by partially providing a portion where either one of the large corrugated plate and the small corrugated plate is removed.

[0012]

According to the inventions according to claims 1 and 4, in the portion where the small corrugated plates of the metal catalyst carrier are removed, the intervals between the adjacent large corrugated plates are partially narrowed, and conversely, the intervals are partially separated. It is possible to suppress the occurrence of a widened portion, and when the large-wave plate is coated with the catalyst coating material, there is no portion where the catalyst coating material accumulates, and it is possible to prevent clogging.

Therefore, the corrugated plate surface area (catalyst coating layer surface area) in contact with the exhaust gas is ensured without being reduced, and the catalyst coating material is not wasted. Furthermore,
The exhaust gas and the catalyst coating layer are sufficiently contacted,
It also leads to higher conversion efficiency of the catalyst. In addition, the heat mass can be reduced, and the temperature increase rate of the catalyst carrier can be increased to shorten the heat-up time.

According to the second aspect of the present invention, the other corrugated sheet is stably held in the middle portion of the metal catalyst carrier from which one corrugated sheet is removed. Further, the corrugated sheet surface area (catalyst coating layer surface area) in contact with the exhaust gas can be increased without causing clogging by the catalyst coating material.

According to the third aspect of the invention, the exhaust gas and the catalyst coating layer are more sufficiently contacted with each other, and the conversion efficiency of the catalyst can be further enhanced.

[0016]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, the present invention will be described in detail with reference to the accompanying drawings. FIG. 3 shows the structure of a catalytic converter device 10 that is installed in an exhaust passage of an engine to purify the exhaust gas. At both ends of a cylindrical shell 11 that constitutes the main body of the device, a connection port with an exhaust pipe is provided. And the exhaust gas inlet section 1
2 and an outlet portion 13 are formed.

Both ends of the shell 11 are held by ring-shaped holding members 14 and the metal catalyst carrier 15 of the present invention is incorporated therein. Here, the metal catalyst carrier 15
Is a large corrugated sheet made of metal such as metal foil having a large wave height and a small corrugated sheet made of metal such as metal foil having a small wave height, which are each bent in a wavy shape in one direction. The structure has a space between the exhaust gas passages.

In the metal catalyst carrier 15 according to the present invention, as shown in FIG. 1, the large wave plate 16 and the small wave plate 17 are formed to have substantially the same wave pitch.
The part where either one of the corrugated plate 17 and the small corrugated plate 17 is removed is provided in part. That is, specifically, as shown in FIG. 1, the overlapping portions of the large corrugated plate 16 and the small corrugated plate 17 are located at both ends of the metal catalyst carrier 15, that is, the inlet end and the outlet shown by hatching in FIG. It is formed at the end (see FIG. 4), and as shown in FIG. 2, one of the large corrugated plate 16 and the small corrugated plate 17,
For example, the small corrugated plate 17 is removed and the other, that is, the large corrugated plate 16 is removed.
A portion where only the chisel exists is formed in the intermediate portion between the inlet end and the outlet end (see FIG. 5).

The large corrugated plate 16 has a wave height of 1.2 mm, and the small corrugated plate 17 has a wave height of 0.2 to 0.5 mm. Set to 2-3 mm. According to the structure of the metal catalyst carrier 15 having such a configuration, the following (1) to (3)
Has the action and effect described in. (1) With the conventional configuration in which the flat plates are arranged together with the corrugated plates only at both ends of the metal catalyst carrier 15, there is a possibility that the pitch of each corrugated plate may be displaced in the middle part. Instead, the large corrugated plate 16 and the small corrugated plate 17 are superposed and laminated at both ends of the metal catalyst carrier 15, and the corrugated pitches of both corrugated plates are set to the same pitch. Since it is positioned by the small corrugated plate 17,
The wave pitch of the large corrugated plate 16 does not shift in the middle portion, and the wave pitch is uniform over the entire large corrugated plate 16.

Therefore, in the intermediate portion of the metal catalyst carrier 15 from which the small corrugated plates 17 are removed, there are places where the intervals between the adjacent large corrugated plates 16 are partly narrowed and conversely parts are widened. When the large corrugated plate 16 is coated with the catalyst coating material, there is no part where the catalyst coating material accumulates, and it is possible to prevent clogging from occurring.

Therefore, the corrugated plate surface area (catalyst coating layer surface area) in contact with the exhaust gas is ensured without being reduced, and the catalyst coating material is not wasted. Furthermore,
The exhaust gas and the catalyst coating layer are sufficiently contacted,
It also leads to higher conversion efficiency of the catalyst. (2) By removing the small corrugated plate 17 and providing a portion in which only the large corrugated plate 16 is disposed, the heat mass can be reduced, and the temperature increase rate of the catalyst carrier can be increased to shorten the heat-up time. . (3) The large corrugated plate 16 and the small corrugated plate 17 are connected to the metal catalyst carrier 15
Both corrugated plates 16 and 1
By setting the wave pitch of 7 to the same pitch, the small wave plate 17
Metal catalyst carrier 1 in which only the large corrugated plate 16 is arranged by removing
In the middle part of 5, the space between the adjacent corrugated plates 16 can be narrowed rather than partially, so that the catalyst coating material does not cause clogging.
The corrugated sheet surface area (catalyst coating layer surface area) in contact with the exhaust gas can be increased.

Here, by increasing the wave height of the small corrugated plate 17, the interval between the large corrugated plates 16 shown by H in FIG. 1 can be made small. Therefore, by setting the small corrugated plate 17 to the maximum possible wave height, Large corrugated sheets 1 on both sides with a small corrugated sheet 17 sandwiched therebetween
By reducing the distance H between 6 to the minimum,
It is possible to effectively increase the surface area of the corrugated sheet that comes into contact with the exhaust gas.

In the embodiment described above, the metal catalyst carrier 15 formed by simply laminating the large corrugated plate 16 and the small corrugated plate 17 has been described, but by laminating the large corrugated plate and the small corrugated plate and winding them. The present invention can also be applied to a metal catalyst carrier which is formed into a roll shape as a whole. In addition, the small corrugated plate 17 is removed and the large corrugated plate 16 is removed.
The portion where only the metal is present is formed in the intermediate portion between the inlet end and the outlet end of the metal catalyst carrier 15.
May be removed to form a portion in which only the small corrugated plate 17 is present. The point is that the portion in which one of the large corrugated plate 16 and the small corrugated plate 17 is removed is partially provided.

[Brief description of drawings]

FIG. 1 is a diagram showing a relationship between a large corrugated plate and a small corrugated plate of an embodiment of a metal catalyst carrier according to the present invention.

FIG. 2 is a diagram showing a mutual relationship between the large corrugated plates according to the embodiment.

FIG. 3 is a cross-sectional view showing a configuration of a catalytic converter device including the same metal catalyst carrier.

FIG. 4 is a sectional view taken along the line XX in FIG.

5 is a sectional view taken along the line YY in FIG.

FIG. 6 is a view showing a corrugated plate of a conventional metal catalyst carrier.

FIG. 7 is a diagram for explaining the problems of the conventional metal catalyst carrier of the above.

FIG. 8 is a diagram for explaining the problems of the conventional metal catalyst carrier of the above.

[Explanation of symbols]

 15 Metal catalyst carrier 16 Large wave plate 17 Small wave plate

Claims (4)

[Claims] 1. A metal catalyst carrier having a structure in which a large corrugated metal plate having a large wave height and a small corrugated metal plate having a small wave height, which are each bent in a wavy shape in one direction, are alternately laminated and laminated. A metal catalyst carrier, characterized in that the wave pitches of the plate and the small corrugated plate are formed to be substantially the same, and a portion where either one of the large corrugated plate and the small corrugated plate is removed is provided in part. 2. A large wave plate and a small wave plate are overlapped at both ends, and a large wave plate and a small wave plate are removed so that only the other is present between the both ends. The metal catalyst carrier according to claim 1, which is characterized in that. 3. The small corrugated plate is set to a maximum possible wave height so that the interval between the large corrugated plates on both sides of the small corrugated plate is minimized. The metal catalyst carrier according to 1 or 2. 4. A metal catalyst carrier having a structure in which a large corrugated metal plate having a large wave height and a small corrugated metal plate having a small wave height, each of which is bent in a wavy shape in one direction, are alternately laminated to each other and laminated. A metal catalyst carrier characterized in that a plate is positioned by a small corrugated plate, and a portion where either one of the large corrugated plate and the small corrugated plate is removed is partially provided to reduce heat mass.