CN217068375U

CN217068375U - Filter material and bag filter using same

Info

Publication number: CN217068375U
Application number: CN202122627482.1U
Authority: CN
Inventors: 仮屋英树; 高濑阳三
Original assignee: Fuji Corp
Current assignee: Fuji Corp
Priority date: 2021-10-29
Filing date: 2021-10-29
Publication date: 2022-07-29
Anticipated expiration: 2031-10-29

Abstract

The utility model relates to a filter material and a bag filter using the filter material, the filter material is a filter material which uses adhesive and catalyst for removing harmful substances in the gas to be treated to be clamped by a thin sheet which has smaller holes than the particle diameter of the catalyst and has heat resistance, the adhesive makes the catalyst adhere to the thin sheet through the adhesion action of the adhesive in the preparation stage of the filter material so as to prevent the catalyst from falling off, the adhesive is irreversibly denatured due to the heat of the gas to be treated in the use stage of the filter material,the catalyst amount of the catalyst is 250-350 g/m ² . According to this configuration, since the catalyst is sandwiched by the thin sheets having pores smaller than the particle diameter of the catalyst, the catalyst can be effectively prevented from falling off when used for treating the gas to be treated. Therefore, the reduction in the capability of removing the harmful substance due to the falling-off of the catalyst can be avoided, and the harmful substance can be effectively removed for a long period of time.

Description

Filter material and bag filter using same

Technical Field

The utility model is suitable for a handle from the exhaust gas treatment equipment of discharge waste gas such as municipal refuse incineration equipment, sludge incineration equipment, industrial waste incineration equipment, boiler, relate to the filtering material of the harmful substance that handles this waste gas contains and have this filtering material's bag filter.

Background

Exhaust gas discharged from municipal waste incinerators, sludge incinerators, industrial waste incinerators, boilers, and the like contains solid components such as dust, and harmful substances such as nitrogen oxides, sulfur oxides, carbon monoxide, and organic halogen compounds represented by dioxins. As a means for treating exhaust gas containing these harmful substances, for example, a bag filter shown below has been applied.

A bag filter has been proposed in which a catalyst is attached to fibers of a filter cloth and a tetrafluoroethylene resin continuous porous membrane is provided on the surface of the filter cloth on the smoke side (see patent document 1). The bag filter described the effect of preventing the catalyst from falling off by the tetrafluoroethylene resin continuous porous film and preventing the fouling of the catalyst by the soot.

A bag filter has been proposed in which a porous membrane is adhered to one or both surfaces of a filter cloth made of woven or nonwoven fabric on which a particulate exhaust gas treating agent (catalyst) is supported (see patent document 2). The bag filter is described to have an effect of preventing the exhaust gas treating agent from falling off during backwashing by the porous membrane closely attached to the surface of the filter cloth, and preventing the catalyst from being stained by dust or the like.

A bag filter in which both sides of a base fabric on which active fine particles (catalyst) are supported in advance are sandwiched by filter materials has been proposed (see patent document 3). The bag filter describes the effect of preventing the active fine particles from falling off by covering the base fabric loaded with the active fine particles with a filter material.

However, these bag filters support the catalyst by a so-called impregnation method in which a base fabric is immersed in the catalyst in a liquid state and then dried. Therefore, the catalyst may not sufficiently adhere to the base cloth, and the catalyst may fall off from the filter cloth due to impact such as pulse jet during backwashing. Therefore, the harmful substances cannot be sufficiently removed with long-term use, and the service life is shortened. Further, there is a problem that the detached catalyst flows out of the system.

As a means for supporting a catalyst on a fiber material, a filter material in which a catalyst is supported between layers of a three-layer structure by applying the catalyst between the layers and needling the layers, or a filter material in which a catalyst is adhered to a fiber material of each layer in advance by an impregnation method and laminated and then needled has been proposed (see patent document 4). However, in this filter material, the catalyst does not adhere sufficiently to the fibrous material, and therefore the catalyst scatters during the needle punching process, and it is difficult to support a sufficient amount of the catalyst on the product.

Prior art documents:

patent documents:

patent document 1: japanese patent laid-open publication No. H10-230119;

patent document 2: japanese patent laid-open publication No. 11-309317;

patent document 3: japanese patent laid-open publication No. 11-244636;

patent document 4: japanese patent laid-open No. 11-290625.

SUMMERY OF THE UTILITY MODEL

Problem that utility model will solve:

the present invention has been made in view of such circumstances, and an object of the present invention is to provide a filter material and a bag filter having the filter material, in which a catalyst does not substantially fall off during production or use, and harmful substances contained in a gas to be treated can be removed for a long period of time.

Means for solving the problems:

in order to solve the above problems, the present invention relates to a filter medium in which a binder and a catalyst for removing a harmful substance in a gas to be treated are sandwiched by heat-resistant sheets having pores smaller than the particle diameter of the catalyst. The adhesive adheres the catalyst to the sheet by adhesion thereof to prevent the catalyst from falling off during the production stage of the filter material, and does not adhere to the sheet by the heat of the gas to be treated during the use stage of the filter materialReversibly denaturalizing, wherein the catalyst amount of the catalyst is 250-350 g/m ² 。

According to this configuration, since the catalyst is sandwiched by the thin sheets having pores smaller than the particle diameter of the catalyst, the catalyst can be effectively prevented from falling off when used for treating the gas to be treated. Therefore, the reduction in the capability of removing the harmful substance due to the falling-off of the catalyst can be avoided, and the harmful substance can be effectively removed for a long period of time. Further, since the sheet has heat resistance, the gas to be processed can be appropriately treated even under high temperature conditions. The catalyst amount is an amount that enables effective removal of harmful substances contained in the gas to be treated and that ensures a predetermined gas throughput, and the catalyst retention rate of the catalyst amount after pulse back-flushing the bag filter with 30000 times (about 5 years) of pulse injection is 96% or more, and the effective catalyst amount necessary for decomposition of harmful substances in the exhaust gas can be retained.

Further, when the gas to be treated contains dust, the dust can be captured and removed by the sheet, so that the catalyst is not contaminated by the dust, and the harmful substance removing ability of the catalyst can be maintained for a long period of time.

The filter medium according to the present invention is a filter medium in which a binder and a catalyst for removing a harmful substance in a gas to be treated are sandwiched by heat-resistant sheets having pores smaller than the particle diameter of the catalyst. The adhesive enables the catalyst to be attached to the thin sheet through the adhesion effect of the adhesive in the preparation stage of the filter material so as to prevent the catalyst from falling off, and then the adhesive is subjected to heat treatment so as to irreversibly denature, wherein the catalyst amount of the catalyst is 250-350 g/m ² 。

Further, the sheet according to the present invention may be made of a felt texture in which a mesh and a plain cotton-flax fabric are integrally molded. According to this configuration, since the sheet is made of a felt material in which a mesh and a scrim are integrally formed, the perforations of the sheet can be reduced. Further, by adjusting the weight per unit area of the net and the scrim, the perforation of the sheet can be appropriately controlled.

The sheet according to the present invention may have a structure in which a mesh layer, a scrim layer, a catalyst layer, a mesh layer, and a scrim layer are laminated from the upstream side in the flow direction of the gas to be treated.

According to this configuration, since the mesh layer is disposed on the most upstream side in the flow direction of the gas to be treated, the dust contained in the gas to be treated can be reliably captured, and fouling of the catalyst by the dust can be avoided. Further, since the catalyst layer is provided inside the filter medium, the catalyst can be prevented from falling off.

The filter material according to the present invention can be used as a bag filter of any of the above-described forms. As described above, the bag filter disposed downstream of the incinerator or the like that generates the gas to be treated (exhaust gas) containing the harmful substance can obtain the same effects as those described in any of the above embodiments. That is, harmful substances such as dioxins contained in the exhaust gas can be removed appropriately and efficiently.

And, the utility model discloses use bag filter to handle waste gas, its temperature of handling waste gas can be 150 ~ 300 ℃. According to this configuration, it is possible to appropriately remove and effectively treat organic halogen compounds such as dioxins, other organic compounds, harmful substances such as nitrogen oxides and sulfur oxides contained in exhaust gas generated by an incinerator or the like.

The utility model has the advantages that:

according to the present invention, since the catalyst is sandwiched by the sheet and is fixedly attached to the sheet by the adhesive, the catalyst does not fall off in the preparation stage. That is, at the time of preparing the filter material, the catalyst can be prevented from scattering, and the initial catalyst supporting amount can be maintained.

Further, the catalyst is not detached during the use of the filter medium, the catalyst can be retained for a long period of time, and harmful substances such as dioxins contained in the gas to be treated can be appropriately and effectively removed.

Drawings

Fig. 1 is a view showing a schematic structure of a filter material according to the present invention;

fig. 2 is a view showing a schematic structure of another filter material according to the present invention;

fig. 3 is a diagram illustrating a method of manufacturing a filter material according to the present invention;

FIG. 4 is a schematic configuration diagram of an exhaust gas treatment apparatus;

fig. 5 is a diagram showing a state in which exhaust gas is treated by the bag filter according to the present invention;

description of the symbols:

10. 20 Filter Material

11 sheet layer

12 catalyst layer

21 mesh layer

22 scrim (scrim) layer

30 bag type filter

31 off-gas

32 dust

33 hazardous substances

39 clean gas

50 filtering material preparation facilities

51 mixing machine

52 heating device

53 stamping device

54 needling machine

60 exhaust gas treatment equipment

61 incinerator

62 water-cooling device

63 bag filter type dust collecting device

64 blower

65 exhaust tower

66 spraying means.

Detailed Description

The present invention will be described in detail below. The filter material according to the present invention is a filter material in which a sheet having pores smaller than the particle diameter of a catalyst is used to hold and compress an adhesive and a catalyst for removing harmful substances in a gas to be treated, and preferably, the filter material is subjected to needling processing after the catalyst is supported.

The filter material of the present invention can be used as a bag filter for treating a gas to be treated (exhaust gas) containing harmful substances such as dust, organic halogen compounds such as dioxins, nitrogen oxides, sulfur oxides, and carbon monoxide generated in municipal refuse incinerating equipment, sludge incinerating equipment, industrial waste incinerating equipment, and boilers, or as a component of the bag filter.

As the sheet usable in the present invention, a sheet having pores smaller than the catalyst particle diameter can be cited. The pores of the sheet can be appropriately set according to the catalyst particle diameter to such an extent that the passage of the gas to be treated is not hindered, and specifically, the average pore size may be about 10 to 100 μm, preferably 30 to 80 μm, and more preferably 60 to 70 μm. In this way, the use of the sheet having pores smaller in size than the catalyst particle diameter can reliably prevent the catalyst from falling off.

The sheet may be made of heat-resistant fibers, and examples of the heat-resistant fibers include polyamide fibers, polyimide fibers, polyamideimide fibers, polyester fibers, polypropylene fibers, polytetrafluoroethylene fibers, ceramic fibers, and glass fibers.

The sheet preferably uses a felt texture with a mesh and scrim integrally formed. The net may be a net composed of a cotton-like fibrous sheet or a nonwoven fabric, which is formed per unit areaThe weight of (b) may be 200 to 300g/m ² Left and right. The scrim is not particularly limited as long as it is a base material capable of laminating webs, and a scrim composed of a woven fabric, a scrim, a woven fabric, a nonwoven fabric, a net or the like in a lattice shape, and the weight per unit area of the scrim can be 80 to 120g/m ² Left and right. The perforation of the sheet can be appropriately controlled by adjusting the fiber diameter or the weight per unit area of the fibers constituting the web and the scrim.

The method of laminating and integrally molding the net and the scrim can be performed by sewing, needle punching or an adhesive. The laminated structure of the net and the scrim is preferably a scrim having the net laminated on one side of the scrim. Further, a mesh may be laminated on both sides of the scrim, or a plurality of meshes or scrims may be arbitrarily formed in one filter medium.

The adhesive used in the present invention is not particularly limited, but is preferably an adhesive that is irreversibly denatured by carbonization, dissolution, decomposition, shrinkage, or the like when heated to a predetermined temperature. Examples of the adhesive irreversibly denatured by heat (heat-denatured adhesive) include adhesives containing polyvinyl alcohol as a main component.

By using a heat-denatured adhesive as the adhesive, the surface of the catalyst covered with the adhesive can be exposed by a heat treatment (for example, heat setting or actual gas treatment for treating a high-temperature treatment gas). Therefore, the frequency of contact between the harmful substance and the catalyst can be increased at the stage of treating the gas to be treated, and the harmful substance can be decomposed more efficiently. Further, since the denatured adhesive can be adjusted by adjusting the type of the adhesive or the denaturing conditions (heating conditions, use conditions, and the like), the portion where the catalyst is fixed to the sheet remains, and adhesion between the sheet and the catalyst can be reliably maintained, and, for example, the catalyst can be prevented from falling off due to pulse jet at the time of backwashing. That is, the harmful substance removing ability of the catalyst can be surely exerted by denaturing and removing a portion of the adhesive which covers the surface of the catalyst and interferes with the function of the catalyst, and the catalyst can be prevented from falling off by maintaining the adhesive effect by leaving a portion having an adhesive function of adhering the catalyst to the sheet. Further, the catalyst can be adhered to the sheet by a carbide or the like formed by thermally denaturing the adhesive.

As the adhesive, a powder adhesive adjusted to soften by heat treatment to exert an adhesive action or an adhesive adjusted to be in a liquid state can be used. The powdery adhesive is preferable because of its high workability and the ability to easily adjust the amount of the catalyst to be adhered to the sheet. The particle size of the powdery adhesive is preferably about 80 to 120 μm, for example.

The amount of the adhesive can be appropriately set within a range sufficient for the catalyst to adhere and the catalyst surface to be covered or the pores to be blocked due to the excess adhesive as far as possible, and can be adjusted to about 20 to 50%, specifically 100 to 150g/m, of the amount of the catalyst, for example ² Left and right.

The catalyst usable in the present invention is not particularly limited as long as it can effectively decompose harmful substances such as organohalogen compounds typified by dioxins contained in the gas to be treated, and examples thereof include catalysts containing oxides of metals such as titanium, silicon, aluminum, zirconium, gold, platinum, silver, chromium, molybdenum, vanadium, tungsten, cobalt, copper, iron, and manganese.

Among these, preferred is a catalyst in which an oxide of a metal such as titanium, silicon, aluminum, or zirconium is supported on a carrier such that an oxide of a metal such as gold, platinum, silver, chromium, molybdenum, vanadium, tungsten, cobalt, copper, or iron is supported thereon. Particularly preferred is an oxide containing titanium, vanadium and tungsten, i.e., titanium dioxide (TiO) ₂ ) Vanadium pentoxide (V) ₂ O ₅ ) And tungsten trioxide (WO) ₃ ）。

These metal oxide catalysts are preferable because they have high catalytic decomposition ability against harmful substances in the gas to be treated, particularly organic halogen compounds such as dioxins. Of course, harmful substances other than the organic halogen compound, such as other organic compounds, nitrogen oxides, sulfur oxides, carbon monoxide, etc., can be decomposed and removed.

These metal oxide catalysts are preferably powdery catalysts obtained by subjecting honeycomb blocks or the like to treatment such as jet pulverization. The particle size of the catalyst is preferably larger than the pore size of the flake, and can be appropriately set according to the pore size of the flake. Specifically, for example, the average particle size is preferably about 80 to 500. mu.m, more preferably about 100 to 300. mu.m, and most preferably about 100 to 130. mu.m. In this way, by using a catalyst having a particle diameter larger than the pore size of the sheet, the catalyst can be effectively prevented from falling off.

In addition, as the catalyst, a catalyst containing sulfur and/or phosphorus or a compound thereof in a slight amount in the above metal oxide catalyst can be used. By containing these substances in the catalyst, the decomposition action against organic halogen compounds such as dioxins can be further enhanced.

The amount of the catalyst may be appropriately set within a range capable of effectively removing harmful substances contained in the gas to be treated and ensuring a predetermined gas throughput, for example, 200 to 400g/m ² More preferably 250 to 350g/m ² 。

The filter material 10 according to the present invention has a structure in which a sheet layer 11, a catalyst layer 12, and the sheet layer 11 are stacked as shown in fig. 1. When the sheet is a felt having a mesh laminated on one surface of the scrim as described above, the filter material 20 may have a structure in which a mesh layer 21, a scrim layer 22, a catalyst layer 12, a mesh layer 21, and a scrim layer 22 are laminated from the upstream side in the flow direction of the gas to be treated, as shown in fig. 2. By providing the sheet layer 11 or the mesh layer 21 on the most upstream side in the flow direction of the gas to be treated in this manner, it is possible to prevent dust contained in the gas to be treated from entering the filter, and to avoid contamination of the catalyst by the dust. Further, since the catalyst layer 12 is sandwiched by the sheets, the catalyst can be prevented from falling off. The laminated structure of the filter material is not limited to this, and for example, a structure having a protective film layer or the like on the surface of the above-described basic structure, or a structure using a felt-like sheet in which nets are laminated on both surfaces of a scrim, may be used.

The thickness of the filter material is preferably 0.1 to 5mm, and more preferably 1 to 2 mm. When the thickness is within the above range, a predetermined gas flow rate can be secured, and the pressure drop can be reduced when the filter material is used as a bag filter.

Next, a method for producing the filter material will be described with reference to fig. 3. Fig. 3 is a schematic configuration diagram of a manufacturing apparatus used in the manufacturing method of the filter medium. The utility model relates to a preparation method of filtering material has the catalyst loading process that uses the thin slice to clip and compress tightly the adhesive and the catalyst, still has the acupuncture processing procedure after the catalyst loading process. The manufacturing apparatus 50 mainly includes a heating device 52, a pressing device 53 as a pressing device, and a needling machine 54.

After a mixture of the powdery adhesive and the powdery catalyst at a predetermined ratio is sufficiently stirred and mixed in the mixer 51 until the components are uniform, the mixture is spread on the sheet 11 fed from the sheet roller 58 so that the catalyst supporting amount is within a predetermined range, and then another sheet 11 is laminated so as to sandwich the mixture. When the sheet 11 is a felt having a mesh laminated on one surface of a scrim, the mesh layer, the scrim layer, the catalyst layer, the mesh layer, and the scrim layer are laminated in this order.

After lamination, the laminate is heated in a heating device 52 at a temperature at which the powdery adhesive dissolves, and pressed and compressed by a pressing device 53. The adhesive is temporarily dissolved by heat treatment, and the catalyst can be fixed to the sheet 11 by pressing in this state. Then, the filter material 10 having a width of 1.2m and a length of 100m, for example, can be prepared by performing the needling process with the needle punch 54 and winding the filter material around the filter material roll shaft 59 in a state where the catalyst is fixed to the sheet. In this way, since the needling process is performed in a state where the catalyst is fixed to the sheet, the catalyst is not lost in the preparation stage (particularly, in the needling process). In fig. 3, the heating device and the pressing device are provided independently, but the present invention is not limited to this, and for example, the heating device may be omitted by providing a heating function in the pressing device.

In addition, fig. 3 illustrates the case where the adhesive is in a powder form, but the adhesive may be in a liquid form, and in this case, the filter material can be prepared by uniformly spraying the adhesive in a liquid form on a sheet, uniformly scattering the catalyst within a predetermined loading amount range, laminating another sheet (that is, sandwiching the adhesive and the catalyst sheet), pressing, and needle punching.

The filter medium is preferably subjected to a heat-setting treatment at about 250 to 350 ℃, preferably about 300 ℃ for several tens of seconds (for example, 20 to 40 seconds) before being treated with the treatment gas. The heat setting treatment can stabilize the shape and denature the heat-denatured adhesive. In addition, when the filter material is used at a low temperature and the heat-denatured adhesive cannot be denatured in the use stage, the treatment time may be set to several minutes to several tens hours from the viewpoint of thermally denaturing most of the adhesive.

Next, an exhaust gas treatment method for treating exhaust gas by using the filter material as a bag filter will be described. The temperature of the waste gas (actual gas) treated by the bag filter is preferably 150-300 ℃, and more preferably 150-250 ℃. When the use temperature is in the above range, the activity of the catalyst can be improved, harmful substances can be effectively treated, and the temperature is in the heat-resistant temperature range of the constituent element of the filter. When the filter material is used as a bag filter, the filter material is sewn in a bag shape.

Here, fig. 4 is a schematic configuration diagram of an exhaust gas treatment facility 60, which includes an incinerator 61 for incinerating municipal waste, sludge, industrial waste, and the like, a water-cooled temperature lowering device 62, a bag filter type dust collecting device 63 including a bag filter 30 according to the present invention, a blower 64, and an exhaust tower 65. A spraying device 66 as a means for supplying an additive such as a dechlorinating agent or a stripping agent is provided at an upstream position of the bag filter type dust collecting device 63.

The exhaust gas generated in the incinerator 61 is sent to a water-cooled temperature lowering device 62, cooled to a predetermined temperature (for example, 150 to 300 ℃), and then sent to a bag filter type dust collecting device 63. The flue at the upstream side of the bag filter type dust collecting apparatus 63 can supply a dechlorinating agent, a stripping agent, activated carbon, and the like to the exhaust gas sent to the bag filter type dust collecting apparatus 63 by the spraying apparatus 66.

Here, fig. 5 shows a state of the exhaust gas treatment by the bag filter 30. The dust 32 contained in the exhaust gas 31 sent from the upstream side (left-hand side in fig. 5) in the flow direction of the exhaust gas 31 is captured and removed by the outermost mesh layer 21 of the bag filter 30. In addition, dioxins adhering to the dust 32, so-called solid-phase dioxins, can also be removed by the mesh layer 21.

Then, when the exhaust gas 31 after dust removal is passed through the bag filter 30, the exhaust gas is brought into contact with a catalyst supported on the bag filter 30, whereby harmful substances 33 such as organic halogen compounds typified by dioxins, nitrogen oxides, sulfur oxides, and carbon monoxide are decomposed and removed. Thus, harmful substances present in a solid phase and a gas phase can be appropriately removed. In this way, the exhaust gas 31 passes through the bag filter 30 to become the clean gas 39, and is discharged from the exhaust tower 65.

When an additive such as a dechlorinating agent is added to the exhaust gas by the spraying device 66, harmful substances 33 such as hydrogen chloride, nitrogen oxides, and sulfur oxides contained in the exhaust gas are dechlorinated, denitrated, and desulfurized by the alkaline reactant to produce a neutralized product, and the neutralized product is captured and removed as a solid phase component by the bag filter 30. Further, when the stripping agent is contained, clogging of the bag filter 30 due to the solid phase component is prevented.

In the bag filter type dust collector, the pulse jet backwashing treatment is periodically performed to remove solid phase components such as dust adhering to the surface of the bag filter, but the durability of the filter material constituting the bag filter is improved, so that the fall-off of the catalyst due to the backwashing treatment can be avoided. Therefore, the service life of the bag filter can be extended, and the catalyst is not discharged from the exhaust tower.

Example (b):

the present invention will be described in further detail with reference to examples, but the present invention is not limited thereto.

(example 1)

A felt-like sheet is integrally formed by laminating a mesh layer made of polytetrafluoroethylene fibers on one surface of a scrim made of polytetrafluoroethylene fibers, and a pressure-sensitive adhesive mainly composed of polyvinyl alcohol and titanium dioxide (TiO) ₂ ) Vanadium pentoxide (V) ₂ O ₅ ) And tungsten trioxide (WO) ₃ ) The metal oxide catalyst thus constituted is sandwiched between them and is pressed by heat to support the catalyst. Then, a filter material having a structure in which a mesh layer, a scrim layer, a catalyst layer, a mesh layer, and a scrim layer are laminated was prepared by needle punching. Further, the weight per unit area of the adjusting net was 300g/m ² The weight per unit area of the scrim was 100g/m ² The amount of the catalyst is 333g/m ² The amount of the adhesive is 130g/m ² 。

The filter material was sewn into a bag shape as a bag filter (area: 0.24 m) ² The amount of the catalyst: 80g) and, the exhaust gas from the incinerator (exhaust gas flow rate: 1m/min, exhaust gas temperature: at 200 ℃ C.), 98.2% of dioxin can be decomposed and removed.

(example 2)

The amount of catalyst (catalyst retention rate) after pulse jet back-washing was evaluated using the bag filter of example 1. The amount of catalyst after pulse back-washing the bag filter at 30000 times (about 5 years) was 77g (catalyst retention rate was 96.2%), and an effective amount of catalyst required for decomposing harmful substances in exhaust gas was maintained.

Industrial applicability:

the utility model is suitable for a handle from the exhaust gas treatment equipment of exhaust waste gas such as municipal refuse incineration equipment, sludge incineration equipment, industrial waste incineration equipment, boiler, can be as the filtering material who handles the harmful substance that contains in this waste gas.

Claims

1. A filter material characterized in that a binder and a catalyst for removing harmful substances in a gas to be treated are sandwiched between heat-resistant sheets having pores smaller than the particle diameter of the catalyst,

the adhesive is irreversibly denatured by heat of the gas to be treated, the catalyst is adhered to the sheet by the adhesive and sandwiched between the sheets, the filter material has a structure in which a sheet layer, a catalyst layer, and a sheet layer are laminated,

the catalyst amount of the catalyst is 250-350 g/m ² 。

2. A filter material characterized in that a binder and a catalyst for removing harmful substances in a gas to be treated are sandwiched between heat-resistant sheets having pores smaller than the particle diameter of the catalyst,

the adhesive is irreversibly denatured by heat treatment, the catalyst is adhered to the sheet by the adhesive and sandwiched by the sheet, the filter material is formed in a structure in which a sheet layer, a catalyst layer, and a sheet layer are laminated,

the catalyst amount of the catalyst is 250-350 g/m ² 。

3. A filter material as claimed in claim 1 or 2,

the sheet is composed of a felt texture with a mesh and a plain cotton-linen fabric integrally formed.

4. A filter material as claimed in claim 1 or 2,

the sheet has a structure in which a mesh layer, a scrim layer, a catalyst layer, a mesh layer, and a scrim layer are laminated from the upstream side in the flow direction of the gas to be treated.

5. A bag filter, characterized in that,

having a filter material as claimed in any one of claims 1 to 4.

6. The bag filter according to claim 5,

the filtering material is used for treating waste gas in a bag filter, and the temperature for treating the waste gas is 150-300 ℃.