JPH06248941A - Catalyst converter for purifying exhaust gas from fixed generating source - Google Patents

Abstract

PURPOSE:To provide a durable catalyst converter, for purifying exhaust gas from a fixed generating source, in which the outer peripheral part of a ceramics- made catalyst carrier is not broken by stress due to the expansion and contraction of thermal expansive packing material. CONSTITUTION:A catalyst converter 1 for purifying exhaust gas from a fixed source is composed of a tubular housing 2; a catalyst 3, composed of a ceramics- made catalyst carrier arranged in the middle part 20 of the housing 2 and a catalyst layer formed on a surface forming the hole of the catalyst carrier; and ringlike thermal expansion packing material 5, arranged between the housing 2 and the catalyst 3. In the catalyst 3, a ringlike reinforcing part 4 composed of ceramics having the quality same as that of the catalyst carrier is formed on the outer peripheral part of the catalyst carrier abutting on the thermal expansion packing material 5.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a catalytic converter for purifying exhaust gas from a fixed source.

[0002]

2. Description of the Related Art For example, as disclosed in Japanese Patent Laid-Open No. 63-111928 and Japanese Utility Model Laid-Open No. 63-66133, it is installed in a large gas engine with a large amount of exhaust gas or an exhaust gas system such as a boiler. A monolith type catalyst used by being incorporated into an exhaust gas purifying catalyst converter (hereinafter referred to as a catalyst converter) has a thermally expandable packing material interposed between an outer cylinder (catalyst container casing) and the outer cylinder (catalyst container casing). It is known that

The thermally expandable packing material is used as a seal between the outer cylinder and the monolith catalyst, and absorbs the difference in thermal expansion caused by the difference in material between the outer cylinder and the monolith catalyst during purification of exhaust gas. However, it is for preventing the exhaust gas before purification from leaking out.

[0004]

The catalyst converter installed and used in an exhaust gas system such as a gas engine or a boiler, which is a fixed source of the exhaust gas, needs to purify a large amount of exhaust gas. A large monolith catalyst is used. When the catalyst becomes large, a large force is likely to be applied locally, and the catalyst is easily damaged. In particular, when a large ceramic monolith catalyst carrier is used, the outer peripheral portion of the catalyst carrier which is in contact with the thermally expandable packing material is easily damaged.

It is an object of the present invention to provide a catalyst converter for purifying exhaust gas from a fixed source which has durability and has solved the above problems.

[0006]

A catalytic converter for purifying exhaust gas from a fixed generation source according to the present invention has at least a central portion having an inlet for introducing the exhaust gas from the fixed generation source and an outlet for discharging purified gas after catalytic purification. A catalyst comprising a cylindrical housing, a ceramic catalyst carrier arranged in the central portion of the housing and having a large number of holes, and a catalyst layer formed on the surface of the catalyst carrier forming the holes; A catalyst for purifying exhaust gas from a fixed generation source, which comprises a ring-shaped thermally expansive packing material that is disposed between the inner peripheral surface of the central portion of the housing and the outer peripheral surface of the catalyst carrier to prevent leakage of the exhaust gas. In the converter, the catalyst is characterized in that a ring-shaped reinforcing portion made of ceramics of the same quality as the catalyst carrier is formed on an outer peripheral portion of the catalyst carrier that abuts the thermally expandable packing material.

[0007]

The catalyst converter for purifying exhaust gas from a fixed source according to the present invention comprises a ring-shaped reinforcing portion made of ceramics of the same quality as the catalyst carrier on the outer periphery of the ceramic catalyst carrier which is in contact with the thermally expansive packing material. Are formed. Therefore, in the ceramic catalyst carrier, even when the heat-expandable heat-resistant seal material expands and the stress concentrates on the outer peripheral portion, the pressure resistance of the outer peripheral portion is higher than the expansion pressure. Since the strength is strengthened by the reinforcing portion and is high, the strength can be sufficiently endured and damage can be prevented.

Therefore, the catalyst converter for purifying exhaust gas from a fixed source according to the present invention can purify a large amount of exhaust gas and has high durability.

[0009]

EXAMPLE An example of an exhaust gas purifying catalytic converter of the present invention will be described with reference to FIGS. Exhaust gas purifying catalytic converter of the embodiment (hereinafter referred to as catalytic converter) 1
As shown in FIG. 1, is a cylindrical housing 2, a catalyst 3 that is housed in the housing 2 and has a ring-shaped reinforcing portion 4, and a ring that is interposed between the housing 2 and the catalyst 3. And a heat-expandable packing material 5 in the shape of a circle.

This catalytic converter 1 has an engine 8 (see FIG. 3) arranged at a fixed position as a fixed source of exhaust gas.
The exhaust gas system 9 is fixedly held at a predetermined position, and the exhaust gas is purified by a catalytic action. The cylindrical housing 2 is made of stainless steel and has an axial length of about 400 to 800 m.
m, cylindrical central portion 20 having an inner diameter of about 200 to 600 mm
A tapered cylindrical inlet portion 24 connected to the inlet side of the central portion 20 for introducing exhaust gas from the engine 8;
And a tapered cylindrical outlet portion 27 that is connected to the outlet side of the outlet and discharges the purified gas after catalyst purification.

An inner peripheral surface 21 of the central portion 20 defines a housing chamber, and the catalyst 3 is housed in the central portion 20 via a thermally expandable packing material 5. The central portion 20 has mounting flange portions 22 and 23 at both ends in the axis P direction, and an inner peripheral surface 21 thereof has a ring-shaped first member having an L-shaped cross section and protruding vertically in the radial direction. Stop member (retainer) 6
1 are integrally joined by spot welding (FIG. 5).
reference).

In the accommodating chamber of the central portion 20, along the axial direction thereof, a ring-shaped first heat-resistant elastic member 62 abutting against the first locking member 61, the catalyst 3, and the second heat-resistant elastic member are provided. Member 7
The second locking members 71 are arranged in the order of 2 and assembled, and then have a L-shaped cross section and project vertically in the radial direction.
As a pressing plate in the axis P direction, the second heat resistant elastic member 72
And is spot-welded and fixed to the inner peripheral surface 21 of the central portion 20. As a result, the catalyst 3 is elastically held by the first heat resistant elastic member 62 and the second heat resistant elastic member 72 from both sides in the axis P direction.

The inlet portion 24 has mounting flange portions 25 and 26 at both ends in the axis P direction (see FIGS. 1, 2 and 3). One of the flange portions 25 is connected to the flange portion 91 of the first exhaust gas passage 90 of the exhaust gas system 9 connected to the engine 8 by bolts and nuts (not shown). The other flange portion 26 is connected to the flange portion 22 of the central portion 20 by bolts and nuts (not shown).

The outlet portion 27 has mounting flange portions 28 and 29 at both ends in the axis P direction. One flange part 2
8 is connected to the flange portion 23 of the central portion 20 by bolts and nuts (not shown). The other flange portion 29 is connected to a flange portion 94 of the second exhaust gas passage 92 having a silencer (muffler) 93 by bolts and nuts (not shown). As shown in FIG. 5, the catalyst 3 has a large number of honeycomb holes 31.
A monolithic catalyst carrier 30 made of ceramics having the above and a catalyst layer (not shown) formed on the surfaces 32 of the large number of honeycomb holes 31. The catalyst 3 is contained in the accommodation chamber of the central portion 20,
The size is set so that the ring-shaped heat-expandable packing material 5 can be placed and accommodated.

The monolith catalyst carrier 30 is a ceramic
A heat-resistant fiber corrugated honeycomb structure was used. Sera
Mick has a coefficient of thermal expansion of 3 to 4 × 10.^-6SiO.
Al ₂0₃Is. The catalyst layer is coated with activated alumina
After drying and firing, by supporting the precious metal catalyst component
Has been formed. The catalyst layer may be, for example, an oxidation catalyst or a catalyst.
A source catalyst or a source catalyst can be used.

The ring-shaped reinforcing portion 4 is the same as the ceramic catalyst carrier 30 and has a coefficient of thermal expansion of 3 to 4 × 10 ^-6 .
O. Using a coating material consisting of Al ₂ 0 _3, the catalyst carrier 30
2 to 30 mm in the radial direction from the outer peripheral surface of, and a thickness of 0.05 to
It is configured by coating to 2 mm. The reinforcing portion 4 may be formed in the entire area of the catalyst carrier 30 in the axis P direction or may be formed in a ring shape having a predetermined width in the axis P direction.

As the heat-expandable packing material 5, a ring-shaped interram (registered trademark of 3M) having elasticity and heat-expansion property was used. Assembled catalytic converter 1
In the accommodating chamber of the cylindrical central portion 20 of the housing 2, the thermally expandable packing material 5, the reinforcing portion 4, and the catalyst carrier 30 are arranged in this order from the inner peripheral surface 24 toward the center. Further, the catalyst 3 has a ring-shaped reinforcing portion 4 made of the same ceramics as the catalyst carrier 30 made of ceramics on the outer peripheral portion 33 of the catalyst carrier 30 that contacts the thermally expandable packing material 5. Therefore, the outer peripheral portion 33 of the catalyst carrier 30 is reinforced by the reinforcing portion 4 on the side held by the inner peripheral surface 50 of the thermally expandable packing material 5.

The catalytic converter 1 configured as described above
Is the exhaust gas system 9 of the engine 8 as shown in FIG.
Is used between the first exhaust gas passage 90 and the second exhaust gas passage 92 forming the. Then, a large amount of exhaust gas generated and discharged from the engine 8 is introduced from the first exhaust gas passage 90 into the inlet portion 24 of the catalytic converter 1 (see FIG. 1,
4), and passes through many honeycomb passages 31 of the catalyst 3 arranged in the central portion 20 (see FIG. 5). At this time, the exhaust gas comes into contact with the catalyst layer and is purified by the catalytic reaction. The purified exhaust gas is guided from the central portion 20 to the second exhaust gas passage 92, passes through the silencer 93, and is discharged to the outside through the discharge port 94 (see FIG. 3).

In the catalytic converter 1, because of the high heat exhaust gas from the engine 8 which is a fixed source, the catalyst 3, the thermally expansive packing material 5 and the cylindrical housing 2 are heated and thermally expanded. At this time, since the ceramic catalyst carrier 30 and the cylindrical central portion 20 of the housing 2 have different coefficients of thermal expansion with heating temperature, the interval between the former outer peripheral portion 33 and the latter inner peripheral surface 21 also changes. To do. The thermally expandable packing material 5 absorbs the change in the thickness direction due to this thermal expansion.

When the heat-expandable packing material 5 is pressed in the contracting direction, a reaction force having the same magnitude as the pressing force acts on the catalyst 3. This reaction force is supported by the reinforcing portion 4 of the catalyst 3. Therefore, the outer peripheral portion 33 of the ceramic catalyst carrier 30 can withstand the reaction force, and the catalyst carrier 3
0 is not damaged. Therefore, the stress generated by the expansion and contraction of the thermally expandable packing material 5 does not affect the ceramic catalyst carrier 30. Therefore, even if the ceramic catalyst carrier 30 is large, it can be prevented from being damaged.

[0021]

According to the catalyst converter for purifying exhaust gas from a fixed source of the present invention, a ring shape made of ceramics of the same quality as the catalyst carrier is provided on the outer peripheral portion of the ceramic catalyst carrier that abuts against the thermally expandable packing material. Is formed. Therefore, when the exhaust gas purifying catalyst converter is used, the stress due to the expansion and contraction of the thermally expandable packing material is
It is received by the ring-shaped reinforcement. Then, the ceramic catalyst carrier is protected.

Therefore, the catalytic converter for purifying exhaust gas from a fixed source according to the present invention has high durability.

[Brief description of drawings]

FIG. 1 is a partial vertical cross-sectional view showing a whole part of a catalytic converter for purifying exhaust gas from a fixed generation source according to the present embodiment.

FIG. 2 is a left side view of FIG.

FIG. 3 is an external view showing a usage example of a catalytic converter for purifying exhaust gas from a fixed generation source according to the present embodiment.

FIG. 4 is a vertical sectional view showing a main part in FIG.

5 is an enlarged vertical sectional view showing a part of FIG. 4 in an enlarged manner.

6 is a cross-sectional view taken along the line AA in FIG.

FIG. 7 is an enlarged view showing a part of FIG. 6 in an enlarged manner.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Exhaust gas purifying catalytic converter 2 ... Cylindrical housing 20 ... Central part 21 ... Housing inner peripheral surface 22, 23 ... Flange part 24 ... Inlet part 25, 2
6 ... Flange part 27 ... Exit part 28, 29 ... Flange part 3 ... Catalyst 30 ... Ceramic catalyst carrier 31 ... Many honeycomb holes 32 ... Hole surface 33 ... Catalyst outer peripheral part 4 ... Ring-shaped reinforcing part 5 ... Ring-shaped thermally expandable packing material 50 ... Inner peripheral surface of thermally expandable packing material 51 ... Outer peripheral surface of thermally expandable packing material 61 ... Ring-shaped first positioning member (retainer) 62 ... Ring-shaped first elastic member 71 ... Ring-shaped second positioning member (holding plate) 72 ... Ring-shaped second elastic member 8 ... Engine arranged at a fixed position 9 ... Exhaust gas system 90 ... First exhaust gas passage 92 ... Second exhaust gas passage 94 ...
Muffler

Claims (1)

[Claims] 1. A cylindrical housing having at least a central portion having an inlet for introducing exhaust gas from a fixed source and an outlet for discharging purified gas after catalyst purification, and a large number of holes arranged in the central portion of the housing. Between the inner peripheral surface of the central portion of the housing and the outer peripheral surface of the catalyst carrier, the catalyst comprising a ceramic catalyst carrier having a catalyst and a catalyst layer formed on the surface of the catalyst carrier forming the holes. A catalytic converter for purifying exhaust gas from a fixed generation source, which comprises a ring-shaped thermally expansive packing material arranged to prevent leakage of the exhaust gas, the catalyst being in contact with the thermally expansive packing material. A catalytic converter for purifying exhaust gas from a fixed source, characterized in that a ring-shaped reinforcing portion made of ceramics of the same quality as that of the catalyst carrier is formed on the outer peripheral portion of the catalyst carrier.