JP2001201033A - Exhaust gas processor having honeycomb-type molded item and its clogging preventive method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method of efficiently preventing the clogging caused by dust, without degrading catalyst efficiency or heat efficiency, in a honeycomb type of molded catalyst for processing the exhaust gas including fine particles such as dust, or in the honeycomb type of molded heat accumulator of a heating deodorizing furnace used for processing of the similar exhaust gas. SOLUTION: Spheres are arranged on one side or both sides of a honeycomb type of molded item, and the spheres shift properly up and down and right and left on the honeycomb molded item by the balance between the force of gas flowing in and/or flowing out and the dead weight of the spheres, and deposits are wiped off or scattered by the shock or friction at that time.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an exhaust gas treatment device containing dust having a honeycomb-shaped formed body, and more particularly, to catalytic combustion or direct combustion of combustible harmful components and combustible malodorous components contained in exhaust gas. The present invention relates to a heat storage type exhaust gas treatment apparatus having a honeycomb type molded body for converting into a harmless and odorless substance and recovering heat generated at that time and reusing it for exhaust gas treatment, and further relates to a method for preventing clogging of the honeycomb molded body. About.

[0002]

2. Description of the Related Art As a device for converting flammable harmful components and flammable odor components contained in exhaust gas into harmless and odorless substances by catalytic combustion or direct combustion, such as a direct combustion type with a heat exchanger, a catalytic type device, etc. Among them, a heat storage type device has recently been receiving attention from the viewpoint of its thermal efficiency.

[0003] Various structures have been proposed for the structure of the heat storage element used in the heat storage type apparatus, but a heat storage element having a honeycomb structure is often used because of its excellent thermal efficiency. Also, in a catalytic device, a honeycomb-type formed catalyst is similarly used in many cases because of excellent catalytic efficiency.

[0004] However, various factory process exhaust gases from power boilers, internal combustion engines, coke ovens, incinerators, and the like contain fine particles such as dust in addition to combustible harmful components and combustible malodorous components. This has caused problems such as an increase in pressure loss due to the blockage of the honeycomb formed body opening due to dust and an increase in energy consumption.

In order to prevent the above-mentioned blockage, there are conceivable methods such as (a) increasing the opening of the honeycomb formed body, (b) reducing the wall thickness of the honeycomb formed body, and (c) frequent soot blowing. However, in the above method (a), the thermal efficiency and the catalyst efficiency are lowered, and as a result, the total capacity needs to be increased. In the method (b), the mechanical strength of the honeycomb formed body is reduced, and further, in the method (c). The method also reduces the strength of the honeycomb formed body, together with economic reasons.

Japanese Patent Application Laid-Open No. 57-50532 discloses a honeycomb shaped catalyst having a honeycomb cross-sectional shape which is the same as or similar to the cross-sectional shape of the honeycomb shaped catalyst at the front surface of the gas inlet. A honeycomb-shaped protector made of a heat-resistant base material that is not thicker than the wall thickness of the honeycomb-shaped catalyst, and the thickness of the wall in contact with the honeycomb-shaped catalyst is not thinner than the wall thickness of the honeycomb-shaped catalyst, 10 mm in close contact with the inlet or outlet of the honeycomb shaped catalyst
It is described that dust can be prevented from being deposited by attaching the honeycomb type catalyst and the protector so that the honeycomb shapes are substantially overlapped with each other in a state where they are separated from each other or as a hook. I have.

However, it is technically difficult to make the above-mentioned protector substantially adhere to the honeycomb molded catalyst, and a protector having the same or similar honeycomb sectional shape may be difficult depending on the shape. In addition, the honeycomb molded body has a structurally limited longitudinal length due to its mechanical strength and the problem of distortion due to heat generated during sintering. In some cases, the compacts may be used in a plurality of layers. In this case, it is difficult to completely adhere the middle of each layer, and as a result, there is a problem that dust is deposited on each layer. In such a case,
It has been difficult to solve this problem by the above method.

The present invention relates to a honeycomb-type molded catalyst for treating exhaust gas containing fine particles such as dust or a honeycomb-type molded heat storage element of a heating deodorizing furnace used for treating similar exhaust gas without impairing the catalyst efficiency or thermal efficiency. An object of the present invention is to provide a method for efficiently preventing clogging due to dust.

[0009]

Means for Solving the Problems The inventors of the present invention have conducted intensive studies to solve the above-mentioned problems, and as a result, arranged a sphere on one side or both sides of a honeycomb molded body, the force for inflow and / or outflow of gas and the sphere. It has been found that the sphere moves appropriately up, down, left, and right on the honeycomb formed body due to the balance with its own weight, and that the deposit can be wiped or scattered by the impact or friction at that time, and the present invention has been completed.

That is, the present invention relates to an exhaust gas treating apparatus having a honeycomb molded body, wherein a spherical body is arranged on one side or both sides of the honeycomb molded body (claim 1). More specifically, an exhaust gas treatment apparatus having a honeycomb-shaped formed body, wherein the honeycomb-shaped formed body is used by being stacked in a plurality of stages, and a sphere is disposed on one or both surfaces of the entire plurality of stages, and in the middle of each stage. The present invention relates to an exhaust gas treatment device (claim 2).

The exhaust gas treatment apparatus according to claim 1 or 2, wherein a wall surrounding the periphery of the sphere is provided, and the honeycomb molded body is stacked in a single or multiple stages. The exhaust gas treatment device according to any one of claims 1 to 3, wherein a mesh-like structure supporting the sphere is provided on the lowermost surface of the honeycomb molded body. Regarding item 4).

[0012] Further, a honeycomb-shaped formed body stacked in a single or a plurality of stages is arranged as a heat storage in a plurality of chambers communicating with the combustion chamber, and supply of a gas to be processed to each chamber is performed.
The exhaust gas processing apparatus according to any one of claims 1 to 4, wherein the exhaust gas is processed while sequentially switching the supply of the purge gas and the exhaust of the processing gas oxidized and decomposed in the combustion chamber.

The exhaust gas treatment apparatus according to any one of claims 1 to 5, wherein the maximum width of the sphere is larger than the maximum width of each opening of the honeycomb molded body. The exhaust gas treatment apparatus according to any one of claims 1 to 6, wherein the sphere is made of ceramics. 8. The method according to claim 1, wherein the number is used.
The present invention relates to an exhaust gas device according to any one of claims 1 to 7.

Further, the present invention relates to an exhaust gas treating apparatus according to any one of claims 1 to 8, wherein the exhaust gas is an exhaust gas containing dust. Furthermore, in an exhaust gas treatment device having a honeycomb-shaped formed body, a sphere is arranged on one or both sides of the honeycomb-shaped formed body, and the sphere moves up and down and / or left and right with the inflow and / or outflow of gas. The present invention relates to a method for preventing clogging of a honeycomb molded body, which comprises removing deposits at openings of the honeycomb molded body.

[0015]

BEST MODE FOR CARRYING OUT THE INVENTION The honeycomb molded body used in the present invention is used as a heat storage body in an exhaust gas treatment device, and the catalyst is coated on the inner wall of each cell of the molded body or the catalyst is contained in the material. It functions as a catalyst by mixing and molding. The honeycomb molded body is formed by, for example, arranging single bodies made of cordierite porcelain or the like in parallel in a plane. The honeycomb single body usually has a height of 5 to 30 cm and a relatively fine opening density of the whole formed body of 50 to 400 cells / inch ² in consideration of thermal efficiency or catalytic efficiency. In addition, the shape of the opening of the cell is a polygon such as a triangle, a square, a hexagon, and an octagon,
Other shapes such as a circle and a sign wave may be used, but a quadrangle is preferable in terms of manufacturing.

The honeycomb molded body may be used alone, but may be used in a plurality of layers in consideration of thermal efficiency, catalytic activity and the like. When laminating, it is possible to use the layers in close contact with each other, but since it is technically difficult to achieve complete close contact, an appropriate space can be provided. At that time, as shown in FIG. 3, a spacer 31 can be arranged in the middle of each step to secure a space. The shape, size, height, material and quantity of the spacer
There is no particular limitation as long as each step can be supported at a fixed position. Specifically, when the honeycomb formed body is 150 mm square, an outer frame 130 mm and an inner frame 1
An example is a 10 mm square frame. In order to reliably stack the honeycomb formed body, it is preferable to set the size to be slightly smaller than the outer periphery of the formed body. The spacer also functions as a wall for preventing the sphere from scattering.

When the honeycomb molded body is arranged vertically and a sphere is provided at the lower part, a mesh structure 23 for holding the sphere can be provided as shown in FIG. 2, for example. The mesh structure 23 is not particularly limited as long as the mesh has enough roughness to hold a sphere, and any material can be used as long as it is a heat-resistant material such as ceramic or metal.

The mesh structure is disposed at a distance longer than the maximum width of the sphere with respect to the opening surface, and at a position where the sphere moves up and down, left and right with the inflow and outflow of exhaust gas, and can contact the opening. Is preferred. In addition, a spacer having the same function as described above can be provided between the network structure and the honeycomb formed body.

As shown in FIG. 1, for example, an exhaust gas treatment apparatus having a honeycomb-shaped formed body has a honeycomb-shaped formed body stacked in a single or a plurality of stages in a plurality of chambers communicating with a combustion chamber. In contrast, an apparatus that treats exhaust gas while sequentially switching the supply of the gas to be treated, the supply of the purge gas, and the exhaust of the oxidatively decomposed processing gas in the combustion chamber can be exemplified.

The above three operations can be performed by switching at certain intervals, but can be performed continuously using a special rotary distribution valve or the like as described later. In the case of continuous switching, the movement of the sphere can be promoted and the removal effect can be improved.

This will be described in more detail with reference to FIG. FIG.
For convenience, a description will be given as a heat storage type exhaust gas treatment apparatus, but a honeycomb formed body may be used as a catalyst instead of a heat storage body. In FIG. 1, heat storage chambers (2A, 2B, 2C) in which honeycomb-type heat storage bodies (3a, 3b) are arranged in two stages above and below, and a combustion chamber 5 communicating with the top of these heat storage chambers are provided. At the bottoms of the chambers 2A, 2B and 2C, respective branch pipes of a gas supply pipe 7, a processing gas discharge pipe 8 and a purge gas supply pipe 9 are connected, respectively, and a burner 6 is provided in the combustion chamber 5. It is. Ceramic small balls are provided on the surface of the upper heat storage element 3b, the middle 4 between the upper heat storage element 3b and the lower heat storage element 3a, and the lower surface of the lower heat storage element. A reticulated ceramic plate 16 is provided for support. Also,
Spacers are installed between 4 and 3a and 16.

The gas to be treated is first preheated by ascending and passing through the heat storage section heated and heated in the heat storage chamber 2A, and then oxidized and decomposed in a combustion chamber under a high-temperature atmosphere to become a clean gas. Heat is given to the heat storage body while passing down through the heat storage part of 2B, and exhausted.

In the meantime, in the heat storage 2C, a clean gas is introduced, and the unprocessed gas remaining in the pipe or the heat storage chamber is purged upward in the processing one cycle before, oxidized and decomposed in the combustion chamber, and passed through the heat storage chamber 2B. Exhausted. After a certain period of time has passed in the first cycle, the valves for the processing gas and the purge gas are switched, so that the heat storage chamber 2A, which was on the processing gas inlet side in the first cycle, is purged, and the heat storage body is cooled down to a de-cooled state.
The heat storage chamber 2B, which was on the clean gas outlet side, is on the processing gas inlet side, and the heat storage body has been heated to a temperature-lowering state, and the heat storage chamber 2C, which has been purged, has been on the clean gas outlet side, and the heat storage body has been de-cooled → the temperature has been raised. become. In addition, each switching valve 12a, 12b in FIG.
12c, 13a, 13b, 13c and 14a, 14b,
In FIG. 14c, □ indicates an open state, Δ indicates a closed state, and FIG. 1 is a view illustrating the state of the first cycle described above.

After a lapse of a predetermined time in the second cycle, the processing gas and the purge gas valve are switched again, and in the second circle, the heat storage chamber 2A, which has been purged, becomes the clean gas outlet side,
The heat storage body is de-cooled → increased temperature, the heat storage chamber 2B on the processing gas inlet side is purged, and the heat storage body is cooled → de-cooled state, and the heat storage chamber 2C on the clean gas output side is processed gas inlet side. The temperature of the heat storage body changes from a temperature rise to a temperature fall. After this state has passed for a certain period of time, by switching the valve again, the original first
By returning to the cycle and sequentially repeating this sequence, the gas to be treated can be efficiently heated and oxidized and decomposed.

The method of the present invention has a structure in which the supply of the gas to be processed, the supply of the purge gas, and the discharge of the processing gas to each heat storage chamber are sequentially switched by a rotary switching valve (distribution valve) as shown in FIG. It can be easily adopted in the processing apparatus which has been used. Further, the present invention can be applied not only to a heat storage body of a honeycomb molded body but also to a honeycomb catalyst.

In FIG. 2, a fixed valve 28 having an opening 28a communicating with each of the heat storage chambers 17, and a processing gas supply opening, a purge gas supply opening (not shown), and a processing gas A switching valve 33 composed of a rotary valve 32 having a discharge opening provided at a predetermined interval in a circumferential direction is attached. The processing gas discharge pipe 34 and the purge gas pipe 20 are connected to the support 19 that rotatably supports the rotary valve 32, while the processing gas supply pipe 18 is connected. In this way, the supply of the gas to be processed, the supply of the purge gas, and the discharge of the processing gas can be sequentially switched by rotating the rotary valve 32 with respect to each heat storage chamber 17.

As shown in FIG. 2B, each opening 28a of the fixed valve 28 and each heat storage chamber 17 are provided with a duct 25 at a lower portion of each heat storage chamber 17, and each opening 28a of the fixed valve 28 is connected to each other. A pipe 26 connects the flange 27 and the duct 25 provided so as to close the pipe.
And the heat storage chamber 17 may be connected so as to correspond one-to-one.

The size of the sphere used is not particularly limited as long as its maximum width is larger than the maximum width of each unit opening of the honeycomb molded body. However, the size of the sphere is taken into consideration in consideration of the inflow or outflow speed of exhaust gas and the weight of the sphere. Adjust the size of the sphere so that it can exercise moderately. For example, a sphere having a maximum width of about 1.1 to 4 times the maximum width of each unit opening of the honeycomb molded body is preferable.

The shape of the sphere does not need to be a true sphere, and any shape which is slightly elliptical can be used.
Alternatively, a hollow sphere can be used in consideration of the weight of the sphere. Further, in order to diffuse the flow of the exhaust gas to promote the movement of the sphere, irregularities may be provided on the surface, or one or more small holes penetrating the surface of the hollow sphere may be provided.

The material is not particularly limited as long as it has heat resistance.
Any of ceramic, metal, etc. can be used,
Ceramics are preferred in consideration of wear resistance and the like. Although the number of spheres to be used is not particularly limited, it is preferable to use 0.2 to 0.7 spheres for the opening of the single honeycomb molded body.

The method of the present invention can be applied to any equipment for treating exhaust gas, but has a remarkable effect particularly in the treatment of exhaust gas containing a large amount of fine particles. Examples of the dust include soot, salt, and the like.

When the exhaust gas containing a large amount of dust passes through the honeycomb molded body and is discharged, it rapidly diffuses, causing turbulence in the air flow, and most of the dust is deposited near the gas outlet. The flow path of each cell is usually about 1 to 2 mm, and when a large amount of dust is continuously discharged, each flow path is immediately blocked by the accumulated dust, causing a large pressure loss. In this case, by arranging the sphere of the present invention on the opening surface, for example,
The sphere is gently blown up due to the outflow of exhaust gas, and the sphere moves up, down, left, and right on the opening surface due to its own weight or turbulence of the air flow due to rotation of the sphere, and the accumulated dust is taken up by impact, friction, etc. This can prevent clogging.

When a plurality of honeycomb molded bodies are stacked and a spacer is provided in the middle, by disposing the spheres in the spacers, the spheres can be prevented from being biased or scattered, and the effect of preventing clogging can be improved. .

[0034]

EXAMPLES The present invention will be described in detail below with reference to examples, but the technical scope of the present invention is not limited to these examples.

Embodiment 100 cells / inch^TwoHoneycomb shape and size 150
mm × 150mm × 150mm heat storage unit and 100 cells / i
nch^TwoThe size is 150mm x 150m with honeycomb shape of
mx300mm heat storage body is stacked on the upper and lower two layers, the lower one
Ceramic nets are placed at 10mm height intervals below
did. Middle and lower thermal storage of upper and lower thermal storage and below
A round bar with a thickness of 10 mm in the middle of the net
Are arranged so that they are in contact with each other, and a square spacer
Used a processing apparatus having eight such heat storage chambers.
Was. When each room is set to 1 to 8 in order, gas supply → gas
Discharge → gas purge process 1, 2, 3 → 4, 5, 6 →
Cycles are sequentially performed with a combination of 7 and 8. Each Hanika
In the upper, middle and lower part of the heat storage
3.1 kg of lamic balls were placed. Calcium carbonate
About 15mg / m ^ThreeBefore exhaust gas containing heat enters heat storage
And heat up to 130 ° C.
Introduce gas by adjusting the wind speed to 4m / sec and burn
Honeycomb regenerator with room temperature maintained at 800 ° C
Continuous operation when oxidized and decomposed in the upper combustion chamber through the inside
The operation was possible without increasing the pressure loss even in two months. Also,
The decrease in thermal efficiency due to the provision of ceramic globules is not
I couldn't. The dust discharged with the exhaust gas is collected separately.
Collected with a dust device.

COMPARATIVE EXAMPLE Exhaust gas was treated in the same manner as in the Example except that no ceramic globules were provided. As a result, pressure loss increased in two weeks of continuous operation, clogging occurred, and cleaning was required.

[0037]

As described above, according to the present invention, the performance (catalytic ability, thermal efficiency) of the honeycomb molded body is not impaired.
In addition, since the clogging of the honeycomb formed body can be effectively prevented in the processing of a gas having a large amount of dust, it is possible to stably operate for a long period of time without having to frequently stop and clean the conventional operation. Was.

[Brief description of the drawings]

FIG. 1 is a schematic view showing a process of treating a gas to be treated by an exhaust gas treating apparatus having a honeycomb molded body of the present invention.

FIG. 2 is a heat storage type exhaust gas treatment apparatus showing a specific configuration of the present invention, wherein (A) is a perspective view and (B) is a perspective view of a main part of (A).

FIG. 3 is a perspective view showing a specific configuration of a main part of the present invention.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Exhaust gas processing apparatus which has a honeycomb type heat storage material (catalyst), 2A, 2B, 2C ... heat storage room (catalyst chamber), 3 ... heat storage material (catalyst), 3a ... upstream heat storage material (catalyst), 3b ... downstream side Heat storage unit (catalyst), 4: Oxidation decomposition chamber (space), 5: Combustion chamber, 6: Burner, 7: Gas supply pipe to be processed, 8: Processing gas discharge pipe, 9: Purge gas supply pipe, 10: Exhaust fan,
11 ... chimney, 12a, 12b, 12c, 13a, 13
b, 13c, 14a, 14b, 14c ... switching valve, 15 ...
Spherical body, 16: spherical support structure, 17: honeycomb-type regenerator, 18: gas supply pipe to be processed, 19: support body, 20: purge gas supply pipe, 21: discharge, 22: spherical body, 23: spherical support body, 24: heat storage element, 25: duct, 26: pipe, 2
7 ... Flange, 28 ... Fixed valve, 29 ... Honeycomb molded body, 30 ... Spherical body, 31 ... Spacer, 32 ... Rotary valve, 3
3 switching valve, 34 processing gas discharge pipe

 ────────────────────────────────────────────────── ─── Continuing from the front page (72) Inventor Akira Beppu F-term in Nihon Soda Co., Ltd. Nihongi Plant Production Engineering Laboratory, Fukusawa 950, Nakago-mura, Nakakubijo-gun, Niigata Prefecture EA08

Claims (10)

[Claims] An exhaust gas treating apparatus having a honeycomb-shaped formed body, wherein a spherical body is arranged on one side or both sides of the honeycomb formed body. 2. An exhaust gas treatment apparatus having a honeycomb-shaped formed body, wherein the honeycomb-shaped formed body is used by being laminated in a plurality of stages, and a sphere is disposed on one or both surfaces of the entire plurality of stages and in the middle of each stage. An exhaust gas treatment device characterized by: 3. The exhaust gas treatment device according to claim 1, wherein a wall surrounding the periphery of the sphere is provided. 4. A honeycomb-shaped formed body laminated in a single or plural stages is vertically arranged, and a mesh-like structure for supporting a sphere is provided on the lowermost surface of the honeycomb-shaped formed body. The exhaust gas treatment device according to claim 1. 5. A honeycomb-shaped formed body laminated in a single or plural stages in a plurality of chambers communicating with a combustion chamber is disposed as a heat storage body, and supply of a gas to be treated and supply of a purge gas to each chamber are provided. The exhaust gas treatment apparatus according to any one of claims 1 to 4, wherein the exhaust gas is treated while sequentially switching the exhaust of the processing gas oxidized and decomposed in the combustion chamber. 6. The honeycomb body according to claim 1, wherein the maximum width of the sphere is larger than the maximum width of each opening of the honeycomb molded body.
An exhaust gas treatment device according to any one of the above. 7. The exhaust gas treatment apparatus according to claim 1, wherein the sphere is made of ceramics. 8. The method according to claim 1, wherein 0.2 to 0.7 spheres are used for the single opening of the honeycomb molded body.
8. The exhaust gas device according to any one of 7 above. 9. The exhaust gas treatment apparatus according to claim 1, wherein the exhaust gas is an exhaust gas containing dust. 10. An exhaust gas treatment apparatus having a honeycomb molded body, wherein a sphere is arranged on one or both sides of the honeycomb molded body, and the sphere moves up and down and / or left and right with the inflow and / or outflow of gas. A method for preventing clogging of a honeycomb molded body, comprising removing deposits at each opening of the honeycomb molded body.