JP2020034179A - Combustion furnace of harmful exhaust gas processing device using generation of magnetic fields - Google Patents

Abstract

To provide a combustion furnace of a harmful exhaust gas processing device using generation of magnetic fields which extends time that the introduced exhaust gas remains in a high temperature range to improve detoxification efficiency.SOLUTION: A combustion furnace A of an exhaust gas processing device B heats exhaust gas to a high temperature, combusts or decomposes the exhaust gas, and exhausts the exhaust gas. The combustion furnace A of the exhaust gas processing device B includes: a cylindrical body 1 in which one end part is closed and the other end part opens; an exhaust gas supply nozzle 9 disposed at the closed end part side of the cylindrical body 1; a burner 8 disposed at the closed end part side of the cylindrical body; and a magnetic field coil 10 disposed on an outer peripheral surface of the cylindrical body.SELECTED DRAWING: Figure 1

Description

  TECHNICAL FIELD The present invention relates to a combustion furnace of a harmful exhaust gas treatment apparatus by generating a magnetic field that removes by burning or thermally decomposing exhaust gas discharged from a semiconductor manufacturing process, for example.

From the manufacturing process of a semiconductor device, silane (SiH _4), disilane (Si ₂ H _6), diborane (B ₂ H _6), phosphine (PH _3), arsine (AsH _3), nitrogen trifluoride (NF ₃₎ or the like It is known that toxic exhaust gas and exhaust gas that adversely affects the global environment, such as fluorides represented by carbon tetrafluoride (CF ₄ ) and sulfur hexafluoride (SF ₆ ), are emitted. . Then, it is required that such exhaust gas be previously harmed when released into the atmosphere.

  Therefore, there has been proposed a toxic exhaust gas treatment method and apparatus capable of satisfying the above-mentioned requirements by burning the above-mentioned exhaust gas to remove the harmful gas, and then releasing it to the atmosphere (for example, see Patent Document 1). . The technique described in Patent Literature 1 introduces the above-described exhaust gas into a cylindrical combustion chamber having one end closed, and uses a burner disposed in the combustion chamber to generate hydrogen, methane, ethane, propane, butane, or the like. The fuel gas is decomposed in a high-temperature portion generated when the fuel gas is burned, or is harmed by burning by the action of combustion-assisting air. Thereafter, the fuel gas is supplied to a water scrubber through a combustion exhaust gas transport passage, and cooled by the water scrubber. At the same time, it absorbs powdery solids, harmful by-product gases, etc., and discharges them to the atmosphere through a predetermined flue.

  Further, the burner for treating a flame-retardant substance described in Patent Document 2 has a combustion cylinder whose one end is closed by a closing wall. It is mounted so that it can converge at substantially the same point on the axis, and is provided so that the exhaust gas containing the flame-retardant substance intersects with the flame near or downstream of the convergence point of the flame. With this technology, high combustion decomposition efficiency can be exhibited, and exhaust gas can be completely rendered harmless.

Japanese Patent No. 2963792 Japanese Patent No. 4528141

  By using the inventions described in Patent Documents 1 and 2, the exhaust gas discharged from the semiconductor manufacturing process can be removed. However, the fact is that there is a demand for the development of a processing device that can always remove harm with higher efficiency.

  An object of the present invention is to provide a combustion furnace of a harmful exhaust gas treatment device by generating a magnetic field, in which the introduced exhaust gas stays in a high-temperature region for a longer time to improve the abatement efficiency.

  In order to solve the above-mentioned problems, a combustion furnace of a representative harmful exhaust gas treatment apparatus by magnetic field generation according to the present invention is a combustion furnace of an exhaust gas treatment apparatus that burns or decomposes and exhausts exhaust gas at a high temperature. A cylindrical body having a closed end and an open end on the other side; an exhaust gas supply port disposed on the closed end of the cylindrical body; and a closed end of the cylindrical body And a magnetic field generating member disposed on the outer peripheral surface of the cylindrical body.

  In the combustion furnace (hereinafter simply referred to as “combustion furnace”) of the harmful exhaust gas treatment apparatus by generating a magnetic field according to the present invention, a burner and an exhaust gas supply port are disposed on the closed end side of the cylinder, and the combustion is performed. The exhaust gas flows substantially linearly from the closed end to the open end. At this time, the burned exhaust gas is turned into plasma.

  For this reason, by applying a magnetic field to the cylindrical body by the magnetic field generating member arranged on the outer peripheral surface of the cylindrical body, the exhaust gas that has been turned into plasma can spirally flow inside the outer cylindrical body. Therefore, the exhaust gas can be captured for a long time in the high temperature region inside the cylindrical body, and the removal efficiency can be improved.

It is a schematic diagram explaining the configuration of the combustion furnace according to the present embodiment. It is a figure explaining an important section of an exhaust gas processing device using a combustion furnace concerning this example.

  Hereinafter, the combustion furnace according to the present invention will be described. The combustion furnace according to the present invention is provided with a harmful exhaust gas treatment device (hereinafter referred to as an “exhaust gas”) that generates a magnetic field that thermally decomposes or burns exhaust gas containing harmful components discharged from a semiconductor manufacturing apparatus or a liquid crystal panel manufacturing apparatus. Processing device ”).

  In particular, by applying a magnetic field to the cylinder that burns the exhaust gas and spirally circulating the exhaust gas that has been burned and turned into plasma, the flow distance in the high-temperature region is lengthened to promote the detoxification associated with the combustion. It was made. In other words, the exhaust gas converted into plasma forms a spiral swirling flow, so that the exhaust gas flows over a longer distance than the length of the cylindrical body, so that the abatement efficiency per unit length of the cylindrical body can be improved.

  In the present invention, the cylindrical body has one end closed and the other end open. A burner and exhaust gas supply port are arranged at the closed end, and combustion gas and exhaust gas flow from the burner toward the open end from this end. Is performed.

  The burner disposed at the closed end of the cylinder is for mixing and burning the fuel gas and the supporting gas. The fuel gas is not particularly limited, but methane gas can be preferably used. Also, the supporting gas is not particularly limited, and air or oxygen can be used. However, it is preferable to use oxygen as the supporting gas because the combustion temperature can be increased and the consumption of the fuel gas can be reduced.

  Also, the position and number of burners to be arranged at the end are not limited, and one burner or a circle centered on the center axis of the cylinder is positioned at a position corresponding to the center axis of the cylinder. It is possible to arrange a plurality of burners. In particular, when a plurality of burners are arranged on the circumference, it is preferable that each of the burners is inclined toward the central axis so as to intersect on the central axis.

  The position of the exhaust gas supply port disposed at the closed end of the cylindrical body is not limited in number, and one supply port or the central axis of the cylindrical body is located at a position coinciding with the central axis of the cylindrical body. It is possible to arrange a plurality of supply ports on the circumference around. In particular, when a plurality of supply ports are arranged on the circumference, it is preferable that each supply port is inclined toward the central axis so as to intersect on the central axis.

  As the magnetic field generating member disposed on the outer peripheral surface of the cylindrical body, there is no particular limitation on the material or structure, and a magnetic field coil wound on the outer peripheral surface of the cylindrical body or a permanent magnet disposed at a predetermined position on the outer peripheral surface of the cylindrical body Can be used.

  The cylinder may be constituted by a single cylinder, or may be constituted by using a plurality of cylinders having different diameters and as a multiple body in which a cylinder having a small diameter is fitted inside a cylinder having a large diameter. When the cylindrical body is formed as a multiple body, it is preferable to form a gap between the inner cylinder and the outer cylinder, and it is preferable to fill the gap with nitrogen gas. Further, the cylindrical body may be arranged horizontally or vertically. However, in consideration of the easiness of the natural fall of dust, it is preferable that the dust is vertical. By disposing the cylinder vertically, dust that has been ionized and discharged by the combustion of the exhaust gas or dust that has adhered to the cylinder and has been separated by vibration can drop smoothly.

  Next, the combustion furnace A according to the present embodiment will be described with reference to the schematic diagram of FIG.

  In the present embodiment, the cylindrical body 1 has a double structure including an outer cylinder 1a and an inner cylinder 1b. One end of the tubular body 1 is closed by a closing member 3, and the other end is open. An exhaust pipe 4 is disposed at the open end, and is configured so that the exhaust gas harmed by the exhaust pipe 4 can be exhausted to a subsequent process. A gap 5 is formed between the outer cylinder 1a and the inner cylinder 1b, and the gap 5 is filled with nitrogen gas.

  As described above, the cylindrical body 1 has a structure sandwiched between the closing member 3 and the exhaust cylinder 4, and hermeticity is maintained by the sealing member 6 a disposed at a connection portion between the closing member 3 and the cylindrical body 1. I have. The airtightness of the connection between the cylinder 1 and the tank inlet exhaust port 21 is maintained by the sealing material 6b. The sealing material 6c maintains the airtightness of the connection between the tank inlet exhaust port 21 and the tank inlet flange 22. A gap 5 is formed between the outer cylinder 1a and the inner cylinder 1b, and the gap 5 is filled with nitrogen gas. The heat conduction due to the gas (enclosed nitrogen gas) is small, the cylinder 1 has high heat insulation, and can maintain the temperature in the inner cylinder 1b.

  A burner 8 is disposed on the closing member 3 so as to coincide with the central axis 1c of the cylindrical body 1, and a fuel gas pipe 8a and a combustion supporting gas pipe 8b are connected to the burner 8. The fuel gas pipe 8a is connected to a methane gas supply source (not shown), and the combustion supporting gas pipe 8b is connected to an oxygen gas supply source (not shown).

  Therefore, methane gas and oxygen gas at a preset flow rate are supplied from the supply sources of the respective gases, and can be mixed and burned by the burner 8. In particular, by using oxygen gas as the combustion supporting gas, it is possible to increase the flame temperature, and it is possible to burn or decompose the supplied exhaust gas in a high temperature range to remove the harm.

  A plurality of exhaust gas nozzles 9 serving as exhaust gas supply ports are arranged on a circumference around the burner 8 of the closing member 3. The exhaust gas nozzles 9 are arranged so as to be inclined toward the central axis 1c of the cylinder 1 at a preset angle so as to be able to intersect at substantially the same position. Further, each exhaust gas nozzle 9 is connected to an exhaust gas pipe 9a connected to an exhaust gas supply source (not shown).

  A magnetic field coil 10 is disposed in a state wound around the outer peripheral surface of an outer cylinder 1 a constituting the cylindrical body 1. The magnetic field coil 10 is connected to a power supply (not shown), and it is possible to generate a magnetic field in the longitudinal direction of the cylindrical body 1 by energizing the magnetic field coil 10.

  In the combustion furnace A configured as described above, a magnetic field is formed by energizing the magnetic field coil 10 disposed on the outer peripheral surface of the cylindrical body 1, and a mixed gas of methane gas and oxygen gas is injected from the burner 8 to burn and exhaust gas. Exhaust gas is supplied from the nozzle 9. Exhaust gas is burned with the combustion of the mixed gas from the burner 8 and turned into plasma (charged particles).

  The exhaust gas that has been burned and turned into plasma flows from the closing member 3 side of the cylinder 1 toward the exhaust cylinder 4 while spirally turning under the influence of the magnetic field, and is eliminated in this process.

  That is, the motion of the charged particles in the magnetic field proceeds while maintaining the initial state when the direction of the charged particles and the direction of the magnetic field are the same. Further, when the charged particles are perpendicularly incident on the magnetic field, the charged particles perform a uniform circular motion by the action of the Lorentz force.

  However, the fact that the exhaust gas nozzle 9 is inclined with respect to the central axis 1c of the cylindrical body 1 and that the exhaust gas burned and converted into plasma under the influence of the flame of the burner 8 becomes the same direction as the direction of the magnetic field is not considered. Absent. In addition, since the exhaust gas that has been turned into plasma has a speed corresponding to the injection speed from the exhaust gas nozzle 9, constant velocity circular motion based on a vertical component with respect to the magnetic field and constant velocity linear motion based on the same component with respect to the magnetic field are obtained. Take a combined spiral motion.

  Therefore, the exhaust gas that has been turned into plasma spirals inside the cylinder 1 from the closing member 3 side to the exhaust cylinder 4 side, so that the traveling distance of the exhaust gas becomes sufficiently larger than the length of the cylinder 1 and the burner. 8 will be affected by the flame for a long time. For this reason, it is possible to remove the exhaust gas without increasing the length of the cylinder 1. That is, it is possible to improve the abatement efficiency in the combustion furnace A.

  Note that the combustion furnace A is not limited to the structure in which the cylinder 1 is erected in the vertical direction as in the present embodiment, but may be a structure in which the cylinder 1 is arranged horizontally. That is, the combustion furnace A may be any as long as it has the cylinder 1 arranged in the vertical or horizontal direction, the burner 8 arranged on the closed end face of the cylinder 1, and the exhaust gas nozzle 9. .

  In the present embodiment, a magnetic field coil is used as the magnetic field generating member disposed on the outer peripheral surface of the cylinder 1, but a permanent magnet may be used. When a permanent magnet is used as the magnetic field generating member, a plurality of arc-shaped permanent magnets having a thickness direction of an N-pole and an S-pole are used, and these permanent magnetic forces are arranged so as to surround the outer peripheral surface of the cylindrical body and in the longitudinal direction. It may be arranged in a predetermined range along.

  Next, the configuration of the exhaust gas treatment apparatus B using the combustion furnace A as described above will be briefly described with reference to the schematic diagram of FIG.

  A combustion gas passage 16 communicating with a water scrubber 15 is connected to the exhaust pipe 4 disposed below the cylindrical body 1 constituting the combustion furnace A. The combustion gas passage 16 connects the cylindrical body 1 and the water scrubber 15 and moves up and down in a preset range, but stores water so that a substantially constant water level can be maintained in the range. Is formed.

  The water scrubber 15 is for removing dust components and gas components contained in the burned exhaust gas, and is configured integrally with the combustion furnace A via a tank 17. The water scrubber 15 is composed of a cylinder 18 arranged above the tank 17. An opening 18a connected to the combustion gas passage 16 is formed below the cylinder 18, and a discharge port 18b is formed above. Further, a filtering member 19 and a draining member 20 are arranged inside the cylinder 18.

  A suction member (not shown) is connected to the discharge port 18 b of the water scrubber 15, and the negative pressure generated by the suction member is configured to act on the combustion furnace A via the discharge port 18 b of the water scrubber 15. I have.

  In the exhaust gas treatment device B configured as described above, when water is supplied to the filtration member 19 of the water scrubber 15 to form a water film and the suction member is operated, the water scrubber is operated with the operation of the suction member. 15. The inside of the combustion furnace A becomes negative pressure, and a series of gas passages is formed through these.

  In the cylindrical body 1, a flame in which methane gas and oxygen gas are burned from the burner 8 is formed, and exhaust gas is supplied from an exhaust gas nozzle 9. The harmful components of the exhaust gas are supplied to the water scrubber 15 through the exhaust pipe 4 in a helical manner while the harmful components of the exhaust gas are removed by combustion or thermal decomposition by the flame formed in the burner 8. Dust components generated by combustion and thermal decomposition of the exhaust gas fall into the tank 17.

  In the water scrubber 15, high-temperature combustion gas is washed by passing through a water film formed on the filter member 19. Then, the exhaust gas that has been abated and cooled is discharged from the discharge port 18b of the water scrubber 15 to the atmosphere via a suction member.

  INDUSTRIAL APPLICABILITY The combustion furnace according to the present invention is advantageous for use when removing exhaust gas discharged from a semiconductor or other manufacturing process.

Reference Signs List A Combustion furnace B Exhaust gas treatment device 1 Cylindrical body 1a Outer cylinder 1b Inner cylinder 1c Center shaft 3 Closing member 4 Exhaust cylinder 5 Clearance 6a, 6b, 6c Sealing material 8 Burner 8a Fuel gas pipe 8b Combustible gas pipe 9 Exhaust gas nozzle 9a Exhaust gas piping 10 Magnetic field coil 15 Water scrubber 16 Combustion gas passage 17 Tank 18 Cylinder 18a Opening 18b Discharge port 19 Filter member 20 Drain member 21 Tank inlet exhaust port 22 Tank inlet flange

Claims (3)

A combustion furnace of a harmful exhaust gas treatment device by generating a magnetic field that burns or decomposes and exhausts exhaust gas at a high temperature,
A tubular body having one end closed and the other end open;
An exhaust gas supply port arranged on the closed end side of the cylindrical body,
A burner arranged on the closed end side of the cylinder;
A magnetic field generating member arranged on the outer peripheral surface of the cylindrical body,
A combustion furnace for a harmful exhaust gas treatment device by generating a magnetic field, comprising:   The cylindrical body is composed of an inner cylinder and an outer cylinder, the magnetic field generating member is a magnetic field coil or a permanent magnet disposed on the outer peripheral surface of the outer cylinder, and a gap is formed between the inner cylinder and the outer cylinder. The combustion furnace for a harmful exhaust gas treatment apparatus according to claim 1, wherein:   The cylindrical body is arranged upright, the upper end is closed and the lower end is opened, and the burner is arranged at substantially the center of the closed upper end, and a plurality of cylinders centered on the burner are arranged. The combustion furnace for a harmful exhaust gas treating apparatus according to claim 1 or 2, wherein the exhaust gas supply port is disposed at a position.

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