JP2013103173A - Purification cylinder for exhaust gas including powdered substance - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a purification cylinder for exhaust gas including powdered substances discharged in a semiconductor manufacturing process etc., which removes hazardous components from the exhaust gas to purify the exhaust gas, traps the powdered substances within the purification cylinder and prevents a problem of pressure loss for a short time.SOLUTION: The purification cylinder for exhaust gas including the powdered substances includes an exhaust gas introduction port, a purifying agent filling part, a powdered substance trapping tool and a discharge port for purified gas. The powdered substance trapping tool includes: a disk having an outer peripheral edge coming into close contact with an inner wall face of the purification cylinder and including a hole; and an air permeable recessed container stored so that an upper end thereof is brought into close contact with an edge portion of the hole of the disk. A powdered substance trapping material is installed on the surface of the recessed container on the upstream side of a gas flow passage.

Description

  The present invention relates to a purification cylinder for exhaust gas containing powdered material. More specifically, the present invention relates to an exhaust gas purification cylinder that can easily purify exhaust gas containing powdered substances discharged from a semiconductor manufacturing process and the like, and that can capture powdered substances in the purification cylinder.

  Various gases are used in the semiconductor manufacturing industry, and as hydride gas, arsine, phosphine, silane, diborane, hydrogen selenide and the like are used in large quantities. Since these gases are toxic, the exhaust gas containing them must be purified before being released into the atmosphere after being used in the semiconductor manufacturing process or the like. In addition, solid particulate phosphorus, which is a decomposition product, is contained in the exhaust gas containing phosphine discharged from the semiconductor manufacturing process, silicon dioxide is contained in the exhaust gas containing silane, and selenium is contained in the exhaust gas containing hydrogen selenide. Since they are contained in large quantities, these exhaust gas treatments must be considered so as to remove solid particles such as phosphorus, silicon dioxide, or selenium and to suppress an increase in pressure loss in the purification cylinder. In addition, some pulverized products have an adverse effect on the environment and human body that cannot be released into the atmosphere, and therefore must be reliably removed.

Conventionally, when exhaust gas containing pulverized material is treated with a purification cylinder using a dry treatment method, measures such as installing a filter in the clarification cylinder have been taken. However, a purification cylinder as described in Patent Document 1 has been developed. The purification cylinder is provided with a horizontal plate at a position above the purifier filling portion and below the inlet so that its outer peripheral edge is in close contact with the inner wall surface of the purification cylinder. A flow pipe for flowing through the lower part of the horizontal plate is provided penetrating from the upper direction to the center of the horizontal plate. The inner wall surface of the purification cylinder, the upper surface of the horizontal plate, and the outer surface of the flow pipe The formed annular space is a purification cylinder that serves as a reservoir for powdered substances contained in harmful gas.
JP 2002-66232 A

However, the purification cylinder described in Patent Document 1 is a method of trapping powdered products by naturally dropping them, and could not capture the powdered products efficiently in the purification cylinder.
Therefore, the problem to be solved by the present invention is to purify by removing harmful components from the exhaust gas and purifying the dust inside the purification cylinder in the purification cylinder of the exhaust gas containing powdered substances discharged from the semiconductor manufacturing process etc. The present invention also provides a purification cylinder that does not cause a problem of an increase in pressure loss in the purification cylinder.

  As a result of intensive studies to solve these problems, the inventors of the present invention have, as a result, in a purification cylinder using a dry treatment method, a disk having an outer peripheral edge that is in close contact with the inner wall surface of the purification cylinder, and a hole in the disk. A powder trap having a breathable concave container housed so that the upper end is in close contact with the edge, and a powder trap material is provided on the upstream surface of the gas channel of the concave container Is provided in any part of the exhaust gas flow path to remove and purify harmful components from the exhaust gas and to efficiently capture the pulverized material inside the purification cylinder, and reach the exhaust gas purification cylinder of the present invention. did.

  That is, the present invention is an exhaust gas purification cylinder including an exhaust gas introduction port, a purifier filling portion, a powdered material capturing device, and a powdered material provided with a purified gas discharge port, wherein the powdered material capturing device includes: A disk having an outer peripheral edge in close contact with the inner wall surface of the purification cylinder and having a hole, and a breathable concave container stored so that an upper end thereof is in close contact with an edge of the hole of the disk, the concave container An exhaust gas purifying cylinder containing powdered material, characterized in that a powdered material capturing material is provided on the upstream surface of the gas flow path.

  By the exhaust gas purification cylinder containing the powdered product of the present invention, harmful components can be removed and purified from the exhaust gas discharged from the semiconductor manufacturing process and the like, and the powdered product can be efficiently captured inside the purification cylinder. As a result, it has become possible to prevent the occurrence of the problem that the pressure loss increases in a short time, which is a disadvantage of the purification cylinder in which a filter is installed in the purification cylinder to remove powdered substances.

The present invention is applied to an exhaust gas purification cylinder containing powdered material discharged from a semiconductor manufacturing process or the like.
The exhaust gas that is the gas to be purified in the present invention is not particularly limited as long as it is an exhaust gas containing powdered material. For example, base gas such as nitrogen, hydrogen, argon or helium contains exhaust gas containing phosphine and solid particulate phosphorus, silane gas such as silane, disilane, dichlorosilane and trichlorosilane and solid particulate silicon dioxide. Exhaust gas, exhaust gas containing hydrogen selenide and solid particulate selenium, exhaust gas containing arsine and solid particulate arsenic in the base gas, exhaust gas containing ammonia and solid particulate ammonium chloride, etc. Can do.

Hereinafter, although the purification cylinder of the exhaust gas containing the pulverized product of the present invention will be described in detail with reference to FIGS. 1 to 5, the present invention is not limited thereto.
FIG. 1 is a vertical configuration diagram showing an example of an exhaust gas purification cylinder of the present invention. FIG. 2 and FIG. 3 are vertical configuration diagrams showing an example of the powdered material capturing tool used in the present invention. Moreover, FIG. 4, FIG. 5 is a perspective view which shows an example of the powdered material capture | acquisition tool used for this invention.

  As shown in FIG. 1, the exhaust gas purification cylinder containing the pulverized product of the present invention includes an exhaust gas introduction port 1, a purifier filling portion 2, a pulverized product trap 3, and a purified gas discharge port 4. As shown in FIG. 2, the dust trap 3 has a disc 7 having an outer peripheral edge 5 in close contact with the inner wall surface 5 '(shown in FIG. 1) and having a hole 6 as shown in FIG. 7 has a breathable concave container 9 accommodated so that the upper end 8 ′ is in close contact with the edge 8 of the hole 6, and the powder trapping material is disposed on the upstream surface of the gas channel of the concave container 9. 10 is a purification cylinder.

  In short, the purification cylinder of the present invention has a disk 7 having holes 6 and a powdered material capturing material 10 on the surface at any location in the gas flow path from the exhaust gas inlet 1 to the gas outlet 4. The pulverized product capturing tool 3 composed of a breathable concave container 9 accommodated in a state where there is no gap in the hole 6 is a purification cylinder installed without a gap from the inner wall surface of the purification cylinder. In the purification cylinder of FIG. 1, the powdered product capturing tool 3 is provided on the downstream side of the purifying agent filling unit 2, but the powdered product capturing tool 3 may be provided on the upstream side of the filling unit 2. In the purifying cylinder of the present invention, the eye plate 11 is usually provided below the purifying agent filling portion 2.

In the purification cylinder of the present invention, the disk 7 may have one hole or a plurality of holes, and can be provided at the center of the disk, the periphery of the disk, or both of them. The outer diameter of the disk 7 is substantially the same as the inner diameter of the purification cylinder, and when installed on the purification cylinder, the outer peripheral edge 5 substantially contacts the inner wall surface 5 ′ of the purification cylinder, and the exhaust gas is outside the base 5. It is said that it cannot pass through. Moreover, the thickness of the base | substrate 5 is about 1-20 mm normally.
The disk 7 may be breathable or non-breathable, and as shown in FIG. 3, a powdered material capturing material 10 can be provided on the surface of the disk 7 on the upstream side of the gas flow path. However, in order to increase the gas passage area, the disk 7 is preferably breathable.

  In the purification cylinder of the present invention, the same number of breathable concave containers 9 as the holes of the disk 7 are provided in such a form that the exhaust gas cannot pass through the holes of the disk 7. The outer shape of the container 9 is a cylinder in FIGS. 4 and 5, but is not limited to this, and is not limited thereto, but a prism, a truncated cone with a convex direction downward, a truncated pyramid, a cone, a truncated pyramid, a hemisphere, Similar shapes can be used. The area of the ventilation part in the wall surface of the container 9 is usually 30% or more of the entire wall surface, preferably 50% or more, and more preferably 75% or more. The thickness of the container 9 is usually about 1 to 20 mm, and the powdered material capturing material 10 having a thickness of about 1 to 20 mm is provided on the surface on the upstream side of the gas flow path. The powdered material capturing material 10 is usually provided so that the entire inner wall surface of the container is covered.

  The material of the disk 7 and the breathable concave container 9 used in the purification cylinder of the present invention is not particularly limited as long as it has corrosion resistance against exhaust gas and can support the powdered material capturing material. For example, in addition to metal materials such as carbon steel, manganese steel, chromium steel, molybdenum steel, and stainless steel, ceramic materials, plastic materials, and the like can be used. However, the ventilation portion needs to have a shape having a large number of ventilation holes, for example, porous metal, ceramic, etc., in order to ensure air permeability. The size of the vent hole is preferably such that a sphere having a diameter of 1 mm or less passes through even if it is the smallest vent hole, and a sphere having a diameter of 5 mm or more does not pass through even if it is the maximum vent hole. .

Further, the material of the powdered material capturing material 10 used in the purification cylinder of the present invention is not particularly limited as long as it can easily capture the spherical powdered material having a diameter of 0.1 mm or more contained in the exhaust gas. For example, a glass fiber material, a plastic fiber material, a metal fiber material, a porous material, etc. can be used.
In addition, about the disk used for the purification | cleaning cylinder of this invention, when the shape of the cross section of the inner wall of a purification | cleaning cylinder is not circular, the substitute disk corresponding to the shape can be used suitably. For example, when the shape of the cross section of the inner wall of the purification cylinder is a square, a square board can be used instead of a disk. Such use is also included in the practice of the present invention.

  In the purification cylinder as described above, in order to efficiently capture the pulverized product in the pulverized product capturing tool, the total area of the gas ventilation part (gas passage part) in the pulverized product capturing tool is usually the cross-sectional area ( The diameter, height, number, etc. of the concave container 9 are set so that the area is usually 2 to 10 times, preferably 2.5 to 5 times the area of the cross-sectional area corresponding to the inner diameter). Is done. When the area of the gas ventilation part in the powder trap is less than twice the cross-sectional area of the purification cylinder, the volume of the powder accumulation part in the container is reduced quickly, and the accumulation of powder is accelerated. The area of the part decreases rapidly, which causes an increase in pressure loss. In addition, when the area of the gas ventilation part exceeds 10 times the cross-sectional area of the purification cylinder, there is no particular problem, but the diameter and height are limited by the dimensions inside the purification cylinder, so the diameter and height are Depends on size.

  When using the purification cylinder of the present invention, exhaust gas is discharged from the semiconductor manufacturing process etc. after being connected to the exhaust gas exhaust port of the semiconductor manufacturing process, the gas inlet of the post process, the blower, etc. by piping. Purification and capture and removal of powdered materials are performed. The amount of exhaust gas supplied to the purification cylinder of the present invention is usually set so that the gas cylinder velocity is 0.1 to 100 cm / sec. The pulverized material contained in the exhaust gas mainly accumulates in the inside of the air-permeable concave container 9, and the exhaust gas treatment is performed when the cleaning agent breaks through or the pressure loss becomes larger than the set value due to the accumulation of the pulverized material. For example, the line is switched to an unused purification cylinder line.

  EXAMPLES Next, although an Example demonstrates this invention concretely, this invention is not limited by these.

[Example 1]
(Production of powdered material catcher)
Using a 2 mm-thick SUS316L plate having a large number of holes (diameter 5 mm), it is processed into a concave cylinder having an outer diameter of 50 mm and a height of 65 mm, and this cylinder has a large number of holes (diameter 5 mm) and a diameter. It was attached perpendicularly to a 2 mm thick SUS316L disk having a diameter of 110 mm and a hole with a diameter of 50 mm in the center. Further, a glass fiber material having a thickness of 10 mm was superposed on the upper surface of the disk and the inside of the concave cylinder to produce a powdered material capturing tool as shown in FIG.

(Production of purification cylinder)
Extrusion molding of SUS316L made of SUS316L with an inner diameter of 110 mm and a height of 1000 mm, with a carrier mainly composed of manganese dioxide and copper oxide (made by Nippon Pionics Co., Ltd., diameter 1.5 mm, length 3-10 mm) Article) A purification agent carrying 30 parts by weight of potassium hydroxide with respect to 100 parts by weight was prepared and filled in a purification cylinder so that the filling length was 500 mm. Moreover, the said powdered material capture | acquisition tool was installed in the lower part of the filling part of a cleaning agent like FIG. In addition, in order to measure the collection rate of the powdered material, a filter for reliably capturing the powdered material was installed on the downstream side of the purification cylinder.

(Powder collection rate measurement test)
An exhaust gas containing 1.0 mg / L of SiO ₂ and 1000 ppm of SiH ₄ in dry nitrogen is supplied from the inlet of the purification cylinder so that the empty tube linear velocity in the purification agent filling portion is 5 cm / sec. The amount of powdered material adhering to the filter installed downstream of the purification cylinder was measured. From the results, it was found that the collection rate of the powdered material captured by the powdered material capturing tool was 99.9% or more. During the collection rate measurement test, SiH ₄ was not detected from the outlet gas of the purifier filling portion.

(Pressure loss measurement test of purification cylinder)
In the same manner as described above, an exhaust port containing 1.0 mg / L of SiO ₂ and 1000 ppm of SiH ₄ in dry nitrogen is introduced into the purifying cylinder so that the empty cylinder linear velocity at the purifying agent filling portion is 5 cm / sec. The pressure loss of the purification cylinder after 2 hours, 4 hours, and 6 hours was measured. The results are shown in Table 1. During the pressure loss measurement test, SiH ₄ was not detected from the outlet gas at the purifier filling portion.

[Examples 2 to 4]
Example 1 except that the content of SiO ₂ contained in the exhaust gas was changed to 2.0 mg / L, 3.0 mg / L, and 4.0 mg / L in the collection rate measurement test of the pulverized material in Example 1, respectively. In the same manner as above, a powder collection rate measurement test and a pressure loss measurement test of the purification cylinder were performed. As a result, the collection rate of the powdered material captured by the powdered material capturing tool was 99.9% or more. In addition, Table 1 shows the results of pressure loss of the purification cylinder after 2 hours, 4 hours, and 6 hours. In any case, SiH ₄ was not detected from the outlet gas of the purifier filling portion during the test.

[Comparative Example 1]
In the manufacture of the powdered material capturing tool in Example 1, the same glass fiber material as in Example 1 is overlaid on the upper surface of a flat filter (the same material as in Example 1 (without holes)) instead of the concave cylinder. The powdered product capturing tool for the comparative example was manufactured in the same manner as in Example 1 except that the above-mentioned one was used. Further, in the production of the purification cylinder in Example 1, a purification cylinder was produced in the same manner as in Example 1 except that the powdered material capturing tool for the comparative example was used.
A pressure loss measurement test of the purification cylinder was performed in the same manner as in Example 1 except that this purification cylinder was used. Table 1 shows the results of pressure loss of the purification cylinder after 2 hours, 4 hours and 6 hours. In any case, SiH ₄ was not detected from the outlet gas of the purifier filling portion during the pressure loss measurement test.

[Comparative Examples 2 to 4]
Comparative Example 1 except that the content of SiO ₂ contained in the exhaust gas was changed to 2.0 mg / L, 3.0 mg / L, and 4.0 mg / L in the collection rate measurement test of the pulverized material in Comparative Example 1, respectively. In the same manner, the pressure loss measurement test of the purification cylinder was conducted. The results are shown in Table 1. During the pressure loss measurement test, SiH ₄ was not detected from the outlet gas at the purifier filling portion.

[Example 5]
A quartz tube for decomposing hydrogen selenide to generate powdered selenium was installed in the previous stage of the purification cylinder similar to that used in Example 1. The quartz tube has an inner diameter of 50 mm and a length of 300 mm, and a heater for heating the inside of the quartz tube is provided outside the quartz tube.
In the same manner as in Example 1, after installing the purifying agent and the pulverized product capturing tool in the purifying cylinder, dry nitrogen was introduced from the inlet of the quartz tube so that the empty tube linear velocity at the purifying agent filling portion was 10 cm / sec. While being introduced, the quartz tube was heated so that the temperature inside the quartz tube became 300 ° C. After the temperature inside the quartz tube is stabilized, hydrogen selenide is contained in this dry nitrogen so as to be 3000 ppm, and a pressure loss measurement test is performed in the same manner as in Example 1, and the powder produced by decomposition of hydrogen selenide The amount of selenium adhering to the filter installed on the downstream side of the purification cylinder was measured.

  Next, the same processing as described above was performed without installing the powdered material capturing tool, and the amount of powdered selenium adhering to the filter installed on the downstream side of the purification cylinder was measured. From these results, it was estimated that the collection rate of the pulverized material captured by the pulverized material capturing tool was 99.9% or more. Further, in the same manner as the pressure loss measurement test of Example 1, the pressure loss of the purification cylinder after 2 hours, 4 hours, and 6 hours was measured. The results are shown in Table 2. During the test, hydrogen selenide was not detected from the outlet gas of the purifier filling portion.

[Example 6]
A collection rate measurement test was performed in the same manner as in Example 5 except that the concentration of hydrogen selenide was changed to 6000 ppm in the powder rate collection rate measurement test in Example 5. As a result, it was estimated that the collection rate of the pulverized material captured by the pulverized material capturing tool was 99.9% or more. Further, in the same manner as the pressure loss measurement test of Example 5, the pressure loss of the purification cylinder after 2 hours, 4 hours, and 6 hours was measured. The results are shown in Table 2. During the test, hydrogen selenide was not detected from the outlet gas of the purifier filling portion.

[Comparative Example 5]
In the pressure loss measurement test of the purification cylinder in Example 5, the pressure loss measurement test of the powder was performed in the same manner as in Example 5 except that the same powdered material capturing tool as in Comparative Example 1 was used. Table 1 shows the results of pressure loss of the purification cylinder after 2 hours, 4 hours and 6 hours. In the pressure loss measurement test, hydrogen selenide was not detected from the outlet gas at the purifier filling portion.

[Comparative Example 6]
In the pressure loss measurement test of the purification cylinder in Example 6, the pressure loss measurement test of the powdered material was performed in the same manner as in Example 6 except that the same powdered material capturing tool as in Comparative Example 1 was used. Table 1 shows the results of pressure loss of the purification cylinder after 2 hours, 4 hours and 6 hours. In the pressure loss measurement test, hydrogen selenide was not detected from the outlet gas at the purifier filling portion.

[Example 7]
In the production of the powdered product catcher in Example 1, a powdered product catcher as shown in FIG. 5 was produced in the same manner as in Example 1 except that four concave cylinders having an outer diameter of 30 mm and a height of 65 mm were used. did. Further, in the production of the purification cylinder in Example 1, a purification cylinder was produced in the same manner as in Example 1 except that the powdered material capturing tool was used.
A powder collection rate measurement test was conducted in the same manner as in Example 1 except that this purification cylinder was used. As a result, the collection rate of the powdered material captured by the powdered material capturing tool was 99.9% or more. In any case, SiH ₄ was not detected from the outlet gas of the purifier filling portion during the collection rate measurement test.

  According to the above embodiment, the exhaust gas purifying cylinder using the powdered material capturing device of the present invention allows the exhaust gas discharged from the semiconductor manufacturing process and the like to efficiently and rapidly reduce the powdered powder without increasing the pressure loss. It was confirmed that it was possible to capture.

Configuration diagram in the vertical direction showing an example of an exhaust gas purification cylinder of the present invention The block diagram of the perpendicular direction which shows an example of the powdered material capture tool used for this invention Configuration diagram in the vertical direction showing an example of the powdered material catching tool other than FIG. 2 used in the present invention The perspective view which shows an example of the powdered material capture tool used for this invention The perspective view which shows an example of the powdery material capture tool other than FIG. 4 used for this invention.

DESCRIPTION OF SYMBOLS 1 Exhaust gas introduction port 2 Purifier filling part 3 Powdered material capture tool 4 Gas discharge port 5 Outer peripheral edge of disk 5 'Inner wall surface of purification cylinder 6 Disk hole 7 Disk 8 Edge of disk hole 8' Concave shape Upper end of container 9 Recessed container 10 Powder trapping material 11 Eye plate

Claims (6)

  An exhaust gas purifying cylinder including a powdered material having an exhaust gas inlet, a purifier filling portion, a powdered material capturing device, and a purified gas discharge port, wherein the powdered material capturing device has an outer peripheral edge of the purifying tube A disk having a hole that is in close contact with the inner wall surface and a breathable concave container that is housed so that the upper end is in close contact with the edge of the hole of the disk, and upstream of the gas flow path of the concave container An exhaust gas purifying cylinder containing powdered material, wherein a powdered material capturing material is provided on the surface on the side.   The exhaust gas purifying cylinder containing the pulverized product according to claim 1, wherein a hole of the disk is provided in a center part of the disk and / or a peripheral part of the disk.   The exhaust gas purification cylinder containing pulverized matter according to claim 1, wherein the outer shape of the concave container is a cylinder, a prism, a truncated cone, a truncated pyramid, a cone, a truncated pyramid, or a hemisphere.   The exhaust gas purification cylinder containing a powdered material according to claim 1, wherein a powdered material capturing material is provided on the surface of the disk on the upstream side of the gas flow path in addition to the surface of the concave container.   The exhaust gas purification cylinder containing a powdered product according to claim 1, wherein the total area of the gas ventilation part of the powdered product capturing tool is 2 to 10 times the cross-sectional area of the purification cylinder.   The exhaust gas purifying cylinder containing the pulverized material according to claim 1, wherein the pulverized material capturing material is a glass fiber material, a plastic fiber material, a metal fiber material, or a porous material.

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