JPH06312116A - Dry harmful substance removal device for exhaust gas - Google Patents

Abstract

PURPOSE:To restrain clogging in a harmful substance removal tower by a reaction product and thereby extend the life of a harmful substance removing agent by providing a front stage of a harmful substance removal tower filled with a harmful substance removing agent which detoxifies poisonous gas contained in exhaust gas with a packed tower packed with porous particles of specific granular size. CONSTITUTION:A packed tower 8 packed with porous particles 9 with a particulate diameter of 20 to 50mm is arranged in the first stage of a harmful substance removal tower 6 filled with a harmful substance removing agent 5 which detoxifies poisonous gas contained in an exhaust gas 1. Consequently, clogging due to a reaction product in the harmful substance removal tower 6 is restrained to enable the extension of a life of the harmful substance removing agent 5. Thus it is possible to achieve cost reduction and power saving.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a dry type abatement system for exhaust gas, and more particularly to a dry type abatement system for exhaust gas exhausted during the manufacture of integrated circuits.

[0002]

2. Description of the Related Art Toxic gases exhausted during the manufacture of integrated circuits are generally treated with a wet or dry detoxification device to an allowable concentration or less and then discharged into the atmosphere. Here, the case of the dry type will be described. As shown in FIG. 3, after exhaust gas 1 discharged from the manufacturing apparatus is removed by a dust removing tower 3 equipped with a filter 2 of 8 mesh, for example, the exhaust gas 1 is removed. After passing through the pipe 4 into the abatement tower 6 filled with activated carbon or the like as the abatement agent to adsorb the toxic components, the toxic components are discharged from the exhaust pipe 7. The activated carbon used as the detoxifying agent 5 has a small particle size of about 3 to 10 mm in order to enhance its adsorptivity, and further has a high density to reduce the gap.

[0003]

However, depending on the manufacturing apparatus, the particles produced by the reaction in the apparatus reach the detoxification tower 6 together with the exhaust gas 1 and fill the spaces between the particles of the detoxifying agent 5 and vent the gas. It impairs sex and increases its pressure. Normally, the mechanism of discoloration of the harm-removing agent 5 is generally a mechanism in which the color of the harm-removing agent is reduced when the adsorption capacity is lowered. However, there is a drawback that the labor and cost increase.

Therefore, it is possible to easily remove the reaction product by using the filter 2 having, for example, several tens to several hundreds of meshes. It is clogged and not practical. It is an object of the present invention to provide a dry-type abatement system for exhaust gas, which solves the problems of the prior art as described above.

[0005]

Means for Solving the Problems The present invention is a dry-type abatement device for abatement of toxic gases contained in exhaust gas, wherein a particle size of 20 to 50 mm is provided in front of an abatement tower filled with an abatement agent. The exhaust gas dry abatement device is characterized in that a filling portion for filling the porous particles is arranged. The packing section may be a packing tower arranged in the preceding stage of the abatement tower, or may be an upper part in the abatement tower filled with a harmful agent.

[0006]

[Operation] According to the present invention, a particle size of 20-
A 50 mm porous particle filling section was placed so that the exhaust gas comes into contact with the porous particles with a large adhesion surface area to attach the reaction product, so that the entry of the reaction product into the harmful agent is suppressed. Therefore, it becomes possible to maintain a predetermined breathability for a long period of time.

As the porous particles, those having through holes such as pumice are preferable, but, for example, crushed molten steel slag may be used. Here, the particle size of the porous particles is 20 to
Explaining the reason for 50 mm, if the particle size is less than 20 mm, clogging with porous particles will occur.
If it exceeds mm, the interparticle gap becomes large and the effect of removing the reaction product decreases, so it is necessary to limit it to the range of 20 to 50 mm.

[0008]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a schematic diagram showing the configuration of an embodiment of the present invention. In this figure, the same members as those of the conventional example are designated by the same reference numerals and the description thereof will be omitted. In FIG.
8 is a packed tower provided in front of the abatement tower 6, 9 is a porous particle having a particle size of 20 to 50 mm, and has a predetermined depth h on the wire net 10 stretched under the packed tower 8. Filled with.

Therefore, the particle size of the porous particles 9 is 20 to 50.
Using pumice of mm, the filling depth h is 100 mm and 200, respectively.
mm and 400 mm were laid out in three ways, and an exhaust gas detoxification test exhausted during integrated circuit manufacturing was conducted. The inner diameters of the detoxifying tower 6 and the packed tower 8 used at this time were both 600 mmφ, and activated carbon was used as the detoxifying agent 5. As a result, when the filling depth of pumice was 100 mm, the pressure increased after 4 weeks, and it was found that the reaction product was accumulated on the surface of the harmful remover 5 when decomposed. When the filling depth was 200 mm, it took 3 months for the pressure to rise, and the filling depth of 400 mm was the same as that of 200 mm.

Although there is a slight difference in the filling depth of pumice during the pressure rising period of the above-mentioned example of the present invention, it is 2 of the conventional example using the 8-mesh filter shown in FIG.
The life was long compared to the week. In addition, in the above-mentioned embodiment, the description has been made assuming that the packing tower 8 is provided in the preceding stage of the abatement tower 6, but the present invention is not limited to this, and for example, as shown in FIG. Even if the porous particles 9 having a particle diameter of 20 to 50 mm are filled in the upper stage of the removed harmful agent 5 through the metal net 10 at a predetermined depth h, the same effect can be obtained.

[0011]

As described above, according to the present invention,
Since a packing part of porous particles with a particle size of 20 to 50 mm was placed in front of the detoxifying agent so that the exhaust gas was brought into contact with the porous particles before coming into contact with the detoxifying agent, clogging in the detoxifying tower Can be suppressed, and the life of the harmful agent can be extended thereby, which contributes to cost reduction and labor saving.

[Brief description of drawings]

FIG. 1 is a schematic diagram showing the configuration of an embodiment of the present invention.

FIG. 2 is a schematic diagram showing the configuration of another embodiment of the present invention.

FIG. 3 is a schematic view showing a conventional example of an abatement device.

[Explanation of symbols]

 1 Exhaust gas 5 Harmful agent 6 Harmful tower 8 Packing tower 9 Porous particles

Claims (3)

[Claims] 1. A dry-type abatement device for abatement of toxic gases contained in exhaust gas, in which a packing section in which porous particles having a particle size of 20 to 50 mm are packed in a preceding stage of a detoxification tower packed with a detoxifying agent. Exhaust gas dry-type abatement system characterized by arranging. 2. The exhaust gas dry-type detoxification device according to claim 1, wherein the filling section is a packed column arranged in a stage prior to the detoxification column. 3. The exhaust gas dry abatement apparatus according to claim 1, wherein the filling portion is an upper stage portion in the abatement tower filled with an abatement agent.