JP4536898B2 - MULTILAYER STRUCTURE HONEYCOMB FILTER, DIOXIN REMOVAL / DUST COLLECTION DEVICE USING THE SAME, AND DIOXIN REMOVAL / DUST COLLECTION METHOD - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a multi-layered honeycomb filter, a dioxin removal / dust collection apparatus using the same, and a dioxin removal / dust collection method.
[0002]
[Prior art]
In recent years, when incineration of waste and the like, from the viewpoint of environmental measures such as pollution prevention, the importance of dust collection and dioxin removal methods from incineration exhaust gas and treatment systems using the same are increasing.
[0003]
Under such circumstances, the conventional exhaust gas treatment system is mainly a bag filter using paper, fiber and polymer resin, and the exhaust gas treatment system in which the bag filter is incorporated as a dust collecting filter as shown in FIG. That is, after the high temperature exhaust gas generated in the incinerator 16 is cooled in the cooling tower 20 to a temperature range where the bag filter can be used, the dust is removed through the dust collector 19 incorporating the bag filter 18, In general, the dioxin decomposition catalyst tower 21 decomposes dioxin and releases it to the atmosphere.
[0004]
On the other hand, there is a ceramic honeycomb filter as a dust collecting filter used for the same purpose as the bag filter. The raw material ceramic is excellent in heat resistance and corrosion resistance, and has preferable characteristics as a filter material in a high temperature, corrosive gas atmosphere. Examples of the filter for collecting dust made of ceramics include a tubular shape, or a shape called a candle type having a closed tubular shape. Currently, honeycomb filters for dust collection are used in various fields such as chemical, electric power, steel, and industrial waste treatment industries for the purpose of collecting products from high-temperature gas and removing dust from exhaust gas for environmental measures. Is used.
[0005]
[Problems to be solved by the invention]
However, in the exhaust gas treatment system in which the bag filter is incorporated as a dust collector, the high-temperature exhaust gas is left as it is because the polymer material constituting the bag filter cannot be used in a temperature range of 250 ° C. or higher. Unable to process at temperature. Therefore, it was necessary to incorporate a cooling system before the dust collector. In addition, since the dioxin treatment tower for decomposing dioxin is provided separately from the dust collector, there is a problem that the whole exhaust gas treatment system becomes large and complicated.
[0006]
In addition, the dust collected in the dust hopper 6 still often contains dioxin. Therefore, in order to process this, dust must be once taken out from the dust hopper and decomposed in another processing apparatus, which requires a great deal of labor and time.
[0007]
On the other hand, in an exhaust gas treatment system in which a ceramic honeycomb filter is incorporated as a dust collector instead of a bag filter, it is possible to treat high temperature exhaust gas as it is without cooling, but the other problems are still solved. The current situation is that they are not.
[0008]
The present invention has been made in view of such problems of the prior art, and its object is to collect exhaust gas efficiently generated from a waste incinerator without using a complicated system. To provide a multi-layer structure honeycomb filter capable of performing dust treatment and dioxin removal, a dioxin removal / dust collection apparatus incorporating the multi-layer structure honeycomb filter as a constituent element, and a dioxin removal / dust collection method. It is in.
[0009]
[Means for Solving the Problems]
  That is, according to the present invention, the partition wall portion of the porous substrate having a honeycomb structure is provided.Dust sideOn the surface,One or more layersMade of the same material as the porous substrateA filter layer;Clean sideOne or more layers on the surface ofThe average pore diameter is 1-100 μmA multi-layered honeycomb filter provided with a dioxin decomposition catalyst layer is provided.
[0010]
  In the present invention, the average pore diameter of the porous substrate is 10 to 100 μm, the average pore diameter of the filter layer is preferably 0.1 to 10 μm, and the average pore diameter of the dioxin decomposition catalyst layer is 1-100μmYesFurthermore, the porous base material and the filter layer constituting the multilayered honeycomb filter are made of the same material..
[0011]
On the other hand, according to the present invention, there is provided a dioxin removing / dust collecting device characterized in that a dust hopper in which a heating device is incorporated is installed below the above-mentioned multi-layered honeycomb filter.
[0012]
According to the present invention, the exhaust gas is decomposed into one or more filter layers on one surface of the partition wall of the porous substrate having a honeycomb structure, and one or two or more layers of dioxins are decomposed on the other surface. A first step of introducing the exhaust gas into the dioxin removal / dust collection device in which a dust hopper in which a heating device is incorporated is installed below a multilayered honeycomb filter provided with a catalyst layer, and the exhaust gas, A second step of permeating the multi-layered honeycomb filter from the filter layer side to the dioxin decomposing catalyst layer side; and transmitting the pressurized air from the dioxin catalyst layer side to the filter layer side, A third step of backwashing the honeycomb filter, a fourth step of heating the inside of the dust hopper to decompose and / or vaporize dioxins contained in the dust in the dust hopper, A dioxin removal / dust collection comprising: a fifth step of transmitting the exhaust gas containing dioxin vaporized by the process from the filter layer side of the multilayered honeycomb filter to the dioxin decomposition catalyst layer side. A method is provided.
[0013]
Furthermore, in the present invention, the inside of the dust hopper is preferably heated to 600 to 800 ° C., and the temperature of the exhaust gas that permeates from the filter layer side of the multilayer structure honeycomb filter to the dioxin decomposition catalyst layer side is 200 to 500. It is preferable that it is ° C.
[0014]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, embodiments of the present invention will be described. However, the present invention is not limited to the following embodiments, and may be appropriately selected based on ordinary knowledge of those skilled in the art without departing from the spirit of the present invention. It should be understood that design changes, improvements, etc. may be made.
[0015]
  The multilayered honeycomb filter of the present invention has a partition wall portion of a porous substrate having a honeycomb structure.Dust sideOn the surface,One or more layersMade of the same material as the porous substrateA filter layer;Clean sideOne or more layers on the surface ofThe average pore diameter is 1-100 μmA dioxin decomposition catalyst layer is provided. FIG. 1 is a view for explaining one embodiment of a multi-layer honeycomb filter according to the present invention, wherein (a) is a partial cross-sectional view and (b) is an enlarged schematic view of a D part of (a). As shown in FIG. 1 (a), a general multi-layer structure honeycomb filter used for exhaust gas dust collection or the like has the upstream side B and the downstream side C opposite to the end portions of a large number of through holes 25 of the honeycomb. It is a structure having a sealing part 2 sealed for every square, and the high-temperature gas entering from the upstream side B passes through the porous partition wall part 26 and escapes from the hole on the downstream side C. The dust in the high temperature gas has a mechanism in which it is trapped in the pores in the partition wall portion 26.
  Further, as shown in FIG. 1B, the filter layer 4 is disposed on the upstream side B, that is, the dust side on the surface of the porous substrate 3, and the downstream side C of the surface of the substrate 3. That is, the dioxin decomposition catalyst layer 5 is provided on the clean side.
[0016]
As described above, since the multi-layered honeycomb filter of the present invention is a monolith type filter in which a plurality of layers are macroscopically integrated, the exhaust gas to be treated is passed through in one direction only once. It is possible to simultaneously decompose and remove dust and dioxins. In addition, when the filter is incorporated in an apparatus for exhaust gas treatment or the like, there is no need for further operations such as dioxin removal with respect to the gas after permeation of the filter. -Excellent effects such as space saving.
[0017]
The dioxin decomposition catalyst here is not limited to a specific substance or composition. For example, the main component is titanium oxide, and one or more oxides such as vanadium, molybdenum, and tungsten are added thereto. Is preferably employed. Further, the material constituting the porous substrate and the filter layer of the multilayer honeycomb filter of the present invention is not limited to a specific material, but is a material having heat resistance capable of treating high temperature exhaust gas, Any material having suitable strength and ease of molding may be used. For example, ceramics including cordierite, mullite, alumina and the like are preferably used.
[0018]
The substrate constituting the multilayered honeycomb filter of the present invention is porous, and the average pore diameter is preferably 10 to 100 μm, more preferably 20 to 80 μm, and more preferably 30 to 60 μm. Particularly preferred. Moreover, while the average pore diameter of a porous base material is in the said numerical range, regarding a filter layer, it is preferable that the average pore diameter is 0.1-10 micrometers, and it is further 0.5-8 micrometers. It is preferably 1 to 6 μm.
[0019]
If the average pore diameter of the porous substrate is less than 10 μm, the pressure loss will increase, and if it exceeds 100 μm, sufficient collection efficiency cannot be achieved. Is preferable, and the average pore diameter is suitable for forming a filter layer having an average pore diameter of 0.1 to 10 μm on the surface thereof.
[0020]
Furthermore, the filter layer is also porous, and if its average pore size is less than 0.1 μm, the pressure loss increases, and if it exceeds 10 μm, sufficient collection efficiency can be achieved. In order to eliminate this, it is preferable that the value be defined within the numerical range, which is a numerical range suitable for combining with the porous substrate having the average pore diameter described above to form a multilayered honeycomb filter.
[0021]
  Furthermore, the dioxin decomposition catalyst layer is also porous and has an average pore diameter of 1 to 100 μm.Yes2-80 μmPreferably3-60 μmMorepreferable. If the average pore size of the dioxin decomposition catalyst layer is less than 1 μm, the pressure loss increases, which is not preferable. Moreover, in order to exhibit the catalytic effect for effectively decomposing dioxins contained in the exhaust gas, it is necessary that the catalyst itself has a sufficient surface area. For this reason, the average of the dioxin decomposition catalyst layer When the pore diameter is more than 100 μm, a sufficient catalytic effect cannot be exhibited. Therefore, the numerical range is an average pore diameter suitable for achieving both a pressure loss and a dioxin decomposition catalytic ability as a multilayered honeycomb filter.
  There are many methods for measuring the average pore diameter of the porous body, but the average pore diameter referred to in the present invention is one measured and calculated by the mercury intrusion method.
[0022]
  Further, in the multilayer structure honeycomb filter of the present invention, the porous base material and the filter layer constituting the same are made of the same material..By using the same material, a difference in thermal expansion does not occur even under high temperature conditions. Therefore, the multi-layer structure honeycomb filter according to the present invention may cause separation or dropping of the filter layer due to a difference in thermal expansion between layers even under a high temperature condition of 200 to 500 ° C. or higher, for example. Excellent characteristics such as
[0023]
The multilayered honeycomb filter according to the present invention described so far supplies a slurry of ceramic particles made of the same material as the porous substrate to each cell of the porous substrate having a honeycomb structure. The component is removed by permeating the pores of the porous substrate, the ceramic particles are attached to the surface of the porous substrate, and then fired to form a filter layer.
[0024]
The concentration (w / w) of the ceramic particles in the slurry used for forming the filter layer is 0.5% or more and less than 2.0%. Although it is preferable from the viewpoint of balance with particle adhesion, it is more preferably 0.8% or more and less than 1.5%.
[0025]
The volume of the slurry is preferably 3 to 6 times the volume of the coated cell layer. If it is less than 3 times, there will be a difference in film thickness above and below the cell, and if it exceeds 6 times, the balance between the thickness and concentration of the filter layer and the amount of slurry required for forming the filter layer will be large. This is because the work becomes difficult.
The second and subsequent filter layers are formed by the same method as described above after firing the first filter layer.
[0026]
Next, further details will be described with reference to an example of a method for manufacturing a multilayered honeycomb filter according to the present invention.
Regarding the porous substrate, for example, cordierite is used as a raw material, and a honeycomb structure having a predetermined cell pitch can be manufactured by a general extrusion molding method. Next, as shown in FIG. 1, the ends of the numerous through holes 25 of the honeycomb are sealed using the same material for each cell on the upstream B and downstream C sides. After drying, firing at 1400 ° C. can produce a porous substrate.
[0027]
The filter layer can be manufactured by the processing apparatus 30 shown in FIG. The processing device 30 includes a slurry tank 32 on a magnetic stirrer 31 and supplies the slurry in the slurry tank 32 to the porous substrate 3 by the pressure of air A.
The slurry tank 32 is for preparing a slurry of ceramic particles having a predetermined concentration. A slurry having a uniform concentration is prepared by the stirring action of the magnet stirrer 31, and the prepared slurry is attached to the slurry injection tool 33 to the mounting bracket 34. Is supplied to one end side of the porous base material 3 connected via the, and introduced into the inside from the opening of one cell. The supply amount of the slurry is monitored by a liquid level gauge 35 provided in the slurry tank 32, and the supply of the slurry is stopped when the supply amount reaches a predetermined value. Thereafter, the porous substrate 3 is inverted and the filtered water in the porous substrate is discharged.
[0028]
Moisture in the introduced slurry gradually permeates through the partition walls of each cell and flows to the outside. During this time, particles in the slurry gradually adhere to one side of the partition walls to form a layer made of particles. . The slurry is prepared by adding an organic binder in advance and stirring and mixing with a homomixer in a plastic container.
[0029]
Thus, after forming the layer which consists of ceramic particles, if this is dried and baked at 1350 degreeC for 2 hours, a filter layer can be manufactured.
[0030]
The dioxin decomposition catalyst layer is produced on the other surface of the porous substrate after providing the filter layer by firing on one surface of the porous substrate. That is, a suitable kind of dioxin decomposition catalyst already described is slurried using catalyst particles having a predetermined particle size such that the catalyst concentration (w / w) is 0.5% or more and less than 2.0%. And is supported on the other surface of the porous substrate by the same direct filtration method as that of the filter layer described above. A dioxin decomposition catalyst layer can be manufactured by baking at 400 ° C. for 2 hours after drying.
[0031]
On the other hand, the dioxin removing / dust collecting device according to the present invention is configured by installing a dust hopper in which a heating device is installed below the above-mentioned multi-layered honeycomb filter. FIG. 2 is a schematic view showing a dioxin removing / dust collecting device of the present invention, and FIG. 3 is a schematic view of a dust hopper in which a heating device is incorporated. As described above, the dioxin removal / dust collection device 8 of the present invention is provided with the dust hopper 6 in which the heating device 7 is incorporated below the multilayer filter 1 described above. A dust storage container 11 is disposed, and a dust outlet 14 is provided on a side surface thereof. Further, since the dust hopper 6 is heated and maintained at a high temperature, it is insulated from the surroundings by the heat insulating material 12.
In the dust hopper 6, particularly in the dust container 11, dust that has fallen from the filter layer of the multilayered honeycomb filter 1 by backwashing, or dust that has fallen naturally by gravity without backwashing is collected. It is comprised so that. The dioxin removal dust collector 8 is provided with pipes 10 for introducing and discharging exhaust gas. However, there is no place for exhaust gas to enter and exit outside the pipe 10, and it is airtight as a whole. Needless to say.
[0032]
On the other hand, a backwashing pressurized air inlet 9 is preferably provided on the downstream side of the multilayer honeycomb filter 1, that is, on the clean side, but the dioxin removing / dust collecting device of the present invention is as described above. However, the present invention is not limited to the provision of the introduction port 9, and a system capable of backwashing the multi-layered honeycomb filter 1 may be provided.
[0033]
As shown in FIG. 4, when the exhaust gas sent from the incinerator 16 serving as the exhaust gas source passes through the multilayer honeycomb filter 1, fine dust is captured in the filter layer, and the dioxin decomposition catalyst layer. Dioxin is decomposed and removed in However, the trapped dust still contains dioxin and is collected in the dust hopper 6 disposed below during backwashing.
In the conventional exhaust gas treatment apparatus, the collected dust is taken out of the apparatus and then subjected to incineration. However, in the dioxin removal / dust collection apparatus of the present invention, the dust hopper 6 and the heating device 7 are used. Therefore, there is no need to take out harmful dust to the outside, and dioxins contained in the dust can be thermally decomposed. Further, the gas containing a part of dioxin vaporized without being decomposed is decomposed and removed in the dioxin decomposition catalyst layer when it again passes through the multilayered honeycomb filter 1 installed above.
[0034]
The heating device 7 only needs to be capable of heating to a temperature range sufficient to decompose and / or vaporize dioxins contained in the dust in the dust hopper 6. For example, a heater having a heating wire, gas combustion, etc. Examples thereof include an apparatus and dielectric heating.
[0035]
Although the gas containing dioxin generated by heating the dust hopper 6 is high temperature, as described above, the multilayered honeycomb filter 1 according to the present invention is made of a material having heat resistance, so that It is possible to transmit.
[0036]
Furthermore, the dioxin removal / dust collection method of the present invention includes the first step of introducing exhaust gas into the dioxin removal / dust collection device of the present invention described above, and the exhaust gas from the filter layer side of the multilayer honeycomb filter. A second step of permeating from the dioxin decomposition catalyst layer side to the dioxin decomposition catalyst layer side, a third step of permeating pressurized air from the dioxin catalyst layer side to the filter layer side to backwash the multi-layered honeycomb filter, and inside the dust hopper And the fourth step of decomposing and / or vaporizing dioxins contained in the dust in the dust hopper, and the exhaust gas containing the dioxins vaporized by that step from the filter layer side of the multilayer honeycomb filter again. A fifth step of permeating to the dioxin decomposition catalyst layer side is provided. FIG. 4 is a schematic diagram showing an exhaust gas treatment system that employs the dioxin removal / dust collection method according to the present invention. The exhaust gas generated in the incinerator 16 is introduced into the dioxin removal / dust collection device 8 through the pipe 10 and treated. The process of discharging from the chimney 17 through another pipe 10 after detoxification and dust removal is shown. Hereinafter, each process is divided into details.
[0037]
In the first step, as shown in FIG. 4, exhaust gas generated when incinerating waste or the like in the incinerator 16 is introduced into the dioxin removal / dust collecting device 8. Since the filter 1 has appropriate heat resistance, it is not necessary to provide a cooling device or the like to cool the exhaust gas. In addition, exhaust gas here is not limited to what generate | occur | produces from an incinerator as shown in FIG. 4, It means what contains the fine dust and harmful dioxin which should be processed.
[0038]
In the second step, the exhaust gas introduced into the dioxin removing / dust collecting device 8 is transmitted from the filter layer side of the multilayer honeycomb filter 1 installed in the device to the dioxin decomposition catalyst layer side. As a result, first, fine dust is captured in the filter layer, and then dioxin is decomposed and removed in the dioxin decomposition catalyst layer. When permeating, an appropriate pressure may be applied to the exhaust gas from the filter layer side toward the dioxin decomposition catalyst layer side.
[0039]
Furthermore, in the present invention, when the exhaust gas permeates from the filter layer side of the multilayered honeycomb filter to the dioxin decomposition catalyst layer side, the temperature of the exhaust gas is preferably 200 to 500 ° C, and is preferably 250 to 480 ° C. More preferably, it is particularly preferably 300 to 450 ° C. If it is less than 200 ° C., the effect of the dioxin decomposition catalyst is not sufficient, and even if it exceeds 500 ° C., the effect of the dioxin decomposition catalyst may not be sufficiently exhibited, and the heat resistance of the dust collector itself needs to be enhanced. Therefore, it is not preferable from the viewpoint of cost. Therefore, the temperature of the numerical value is an optimum set temperature for the dioxin decomposition catalyst to function effectively.
[0040]
In the case of the conventional exhaust gas treatment system in which the bag filter is incorporated as a dust collecting filter, the heat resistance temperature of the polymer material constituting the bag filter is limited to less than 250 ° C. It was impossible to treat the exhaust gas at the same temperature. However, in the present invention, the multi-layered honeycomb filter, which is a filter for collecting dust, is mainly composed of ceramics such as cordierite, mullite, alumina and the like, and is sufficient to transmit the exhaust gas in the temperature range. Has heat resistance.
It should be noted that the exhaust gas cooling system such as the cooling tower 20 and the like, which are necessary in the conventional exhaust gas treatment system incorporating a dust collection filter such as a bag filter as shown in FIG. In the present invention, there is no need to provide a dioxin decomposition treatment system such as the dioxin decomposition catalyst tower 21 after the dust filter. Therefore, it has excellent effects such as simplification of the system and simplification of the processing apparatus and space saving.
[0041]
In the third step, the multilayered honeycomb filter 1 is back-washed by transmitting pressurized air from the dioxin catalyst layer side to the filter layer side. At this time, dust that has fallen from the filter layer due to backwashing in the dust hopper 6 installed below the multi-layer structure honeycomb filter 1, particularly in the dust storage container 11, or by gravity without backwashing. It is configured to collect dust that has fallen naturally. Further, it is preferable that a backwashing pressurized air inlet 9 is provided on the downstream side of the multi-layer structure honeycomb filter 1, that is, on the clean side, but the dioxin removing / dust collecting device of the present invention is like this. However, the present invention is not limited to the provision of the introduction port 9, and a system capable of backwashing the multi-layered honeycomb filter 1 may be provided.
[0042]
In the fourth step, the inside of the dust hopper is heated to decompose and / or vaporize dioxins contained in the dust collected therein. Dioxins that have been decomposed and detoxified by heating may be taken out together with dust from the dust outlet 14 shown in FIG. Further, as described above, the dioxins vaporized by heating may pass through the multilayered honeycomb filter installed above the dust hopper again and be discharged after being decomposed and removed by the dioxin decomposition catalyst.
[0043]
Furthermore, in the present invention, the inside of the dust hopper is preferably heated to 600 to 800 ° C, more preferably 650 to 800 ° C, and particularly preferably 700 to 800 ° C. If the temperature is less than 600 ° C., the amount of dioxins increases due to re-synthesis of dioxins, and if it exceeds 800 ° C., it is necessary to construct the dust hopper with a special heat-resistant material, and it is not preferable from the viewpoint of energy cost. Therefore, the temperature of the numerical value is an optimum set temperature for effectively decomposing and / or vaporizing dioxins.
[0044]
In the fifth step, the exhaust gas containing a part of the dioxin evaporated without being decomposed is again permeated through the multilayered honeycomb filter 1 installed at the upper side, and decomposed and removed in the dioxin decomposition catalyst layer. Although the gas containing dioxin generated by heating the dust hopper 6 is at a high temperature, as described above, the multilayer honeycomb filter 1 according to the present invention is made of a material having heat resistance, so that It is possible to transmit. The permeated exhaust gas no longer contains fine dust, dioxin, or the like. For example, it may be discharged to the outside from an exclusion facility such as the chimney 17.
Through the above steps, fine dust contained in the exhaust gas can be effectively collected and dioxin can be decomposed and removed, and the collected dust can also be safely detoxified and disposed of. .
[0045]
【The invention's effect】
As described above, since the multilayered honeycomb filter of the present invention has a predetermined multilayered structure, it is effective and simple to collect dust contained in the exhaust gas and to decompose and remove dioxins. It can be carried out.
Further, the dioxin removal / dust collection apparatus of the present invention is provided with a dust hopper in which a heating device is incorporated below the multi-layered honeycomb filter, so that dust collection and dust collection are performed. It is possible to effectively carry out the treatment of the contained dioxin.
Furthermore, according to the dioxin removal / dust collection method of the present invention, since the multi-layered honeycomb filter and the dioxin removal / dust collection apparatus incorporating the multi-layered honeycomb filter are constituent elements, dust collection and dioxin treatment are performed. As well as simplifying the exhaust gas treatment system, it has excellent effects such as simplification of the treatment apparatus and space saving.
[Brief description of the drawings]
FIG. 1 is a diagram for explaining one embodiment of a multi-layer honeycomb filter according to the present invention, in which (a) is a partial cross-sectional view and (b) is an enlarged schematic view of a D part in (a).
FIG. 2 is a schematic view showing a dioxin removing / dust collecting apparatus of the present invention.
FIG. 3 is a schematic view of a dust hopper in which a heating device is incorporated.
FIG. 4 is a schematic diagram showing an exhaust gas treatment system adopting the dioxin removal / dust collection method according to the present invention.
FIG. 5 is a schematic diagram showing a conventional exhaust gas treatment system.
FIG. 6 is a schematic view showing an example of a method for manufacturing a multilayer honeycomb filter of the present invention.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 ... Multi-layer structure honeycomb filter, 2 ... Sealing part, 3 ... Porous base material, 4 ... Filter layer, 5 ... Dioxin decomposition catalyst layer, 6 ... Dust hopper, 7 ... Heating device, 8 ... Dioxin removal and dust collection Equipment: 9 ... Pressurized air inlet for backwashing, 10 ... Piping, 11 ... Dust container, 12 ... Insulating material, 13 ... Dust, 14 ... Dust outlet, 15 ... Boiler, 16 ... Incinerator, 17 ... Chimney , 18 ... bag filter, 19 ... dust collector, 20 ... cooling tower, 21 ... dioxin decomposition catalyst tower, 25 ... through-hole, 26 ... partition wall part, 30 ... treatment device, 31 ... magnet stirrer, 32 ... slurry tank, 33 ... Slurry injection tool, 34 ... Mounting bracket, 35 ... Liquid level gauge.

Claims (6)

On the dust side surface of the partition wall of the porous substrate having a honeycomb structure , one or two or more filter layers made of the same material as the porous substrate, and one or two layers on the clean side surface A multi-layered honeycomb filter comprising a dioxin decomposition catalyst layer having an average pore diameter of 1 to 100 μm which is equal to or greater than the number of layers.   The multilayer honeycomb honeycomb filter according to claim 1, wherein the porous substrate has an average pore diameter of 10 to 100 µm and the filter layer has an average pore diameter of 0.1 to 10 µm. 3. A dioxin removing / dust collecting apparatus, wherein a dust hopper including a heating device is installed below the multilayered honeycomb filter according to claim 1 or 2 . One or two or more filter layers are provided on one surface of the partition wall of the porous substrate having a honeycomb structure, and one or two or more dioxin decomposition catalyst layers are provided on the other surface. A first step of introducing into a dioxin removal / dust collection device in which a dust hopper in which a heating device is incorporated is installed below the layered honeycomb filter,
A second step of transmitting the exhaust gas from the filter layer side of the multilayered honeycomb filter to the dioxin decomposition catalyst layer side;
A third step of backwashing the multilayered honeycomb filter by transmitting pressurized air from the dioxin decomposition catalyst layer side to the filter layer side;
A fourth step of heating the inside of the dust hopper to decompose and / or vaporize dioxins contained in the dust in the dust hopper;
And a fifth step of passing the exhaust gas containing dioxin vaporized in the step from the filter layer side of the multilayered honeycomb filter to the dioxin decomposition catalyst layer side. Dust method. The dioxin removal and dust collection method according to claim 4 , wherein the inside of the dust hopper is heated to 600 to 800 ° C. The dioxin removal / dust collection method according to claim 4 or 5 , wherein the temperature of the exhaust gas permeating from the filter layer side of the multilayer structure honeycomb filter to the dioxin decomposition catalyst layer side is 200 to 500 ° C.

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