JP2808310B2 - Combustion furnace pressure fluctuation transmission prevention method - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial Application Field) The present invention occurs in the combustion treatment of exhaust gas containing toxic gas represented by arsine, phosphine, diborane, monosilane and the like. The present invention relates to a method for preventing pressure fluctuation of a combustion furnace from being transmitted to a toxic exhaust gas source.

(Problems to be Solved by the Related Art and the Invention) From the semiconductor manufacturing process, toxic exhaust gas containing the above-mentioned gaseous toxic substances is generated. Since such toxic exhaust gas is extremely toxic to the human body, it is necessary to completely remove toxic substances contained in the exhaust gas when releasing the exhaust gas into the atmosphere.

As one of effective methods for removing toxic substances contained in exhaust gas, a combustion method is known (Japanese Patent Application Laid-Open No. Sho 62-62).
-134414, JP-A-62-152517). This method is a method in which toxic substances in exhaust gas are oxidatively decomposed under combustion conditions, and converted into solid substances such as elemental elements and oxides to remove them.

This solid substance is also toxic and must be completely removed from the combustion gas.However, since the solid substance produced is a submicron-sized fine powder because it is produced in the gas phase, the usual solid substance is produced. Significant difficulties arise in completely removing this solid fine powder from the combustion gas in the combustion gas compared to a fine powder of several microns in size. The present inventors have previously made a series of toxic exhaust gases in which a water film is allowed to flow down on the inner wall of the combustion furnace and the solid fine powder is captured and absorbed by the water film in order to efficiently remove such solid fine powder. (Japanese Patent Application No. 63-218389, Japanese Patent Application No. 63-28)
No. 4930).

By the way, in Japanese Patent Application No. 63-231787, the pressure fluctuation of the combustion furnace is controlled by expanding and contracting an elastic member provided in the combustion furnace, but the pressure fluctuation of the combustion furnace exceeds the control capability of the elastic member. In such a case, the pressure fluctuation in the furnace cannot be controlled completely, which may adversely affect the semiconductor manufacturing apparatus connected to the combustion furnace.

(Means for Solving the Problems) The present inventors have conducted intensive studies to prevent transmission of pressure fluctuations occurring in the combustion furnace to the semiconductor manufacturing process, and as a result, a pressure drive was performed on the upstream side of the combustion furnace. An ejector that ejects gas is provided, and the toxic exhaust gas is sucked into the ejector, and the toxic exhaust gas is extracted from the ejector as a mixed gas with the driving gas. Was found to be blocked at the ejector portion and not transmitted to the upstream side thereof, and completed the present invention.

That is, according to the present invention, the toxic exhaust gas from the toxic exhaust gas generation source is sucked into the ejector from which the pressurized driving gas has been ejected, and is taken out from the ejector as a mixed gas with the driving gas, and is burned. A method of introducing into a furnace and burning a burner, wherein a flashback preventing device is not interposed between the ejector and the combustion furnace. Are provided.

(Embodiment of the Invention) An example of an apparatus for carrying out the method of the present invention will be described with reference to the drawings. In Fig. 1, reference numeral 1 denotes a toxic exhaust gas source such as a semiconductor manufacturing apparatus. Reference numeral 2 denotes an adsorption treatment device, 3 denotes a combustion treatment device, 4 denotes a flashback prevention device, and 5 denotes a dust filter. A toxic exhaust gas supply line (piping) from the toxic exhaust gas source is connected to a line 9 connected to the adsorption treatment device 2 by the switching valves 7 and 8 and a line 10 connected to the combustion treatment device 3 via the flashback prevention device 4. Branched to In a normal state, the valve 7 following the adsorption device is closed,
The valve 8 following the flashback prevention device is opened.

The toxic exhaust gas (hereinafter, also simply referred to as exhaust gas) from the toxic exhaust gas source 1 is supplied to the line 6, the valve 8, and the line
After passing through the flashback prevention device 4 through 10, it passes through the line 11, passes through the burner 12, and is ejected into the combustion treatment device 3 for combustion treatment. The flue gas is extracted through a line 13 and discharged to the atmosphere through a dust filter 5 and an exhaust pump 14. In the combustion treatment device 3, fine powder generated by the combustion treatment of the toxic exhaust gas is introduced into the upper end portion of the combustion treatment device via the line 18, and the liquid flowing down the furnace wall as a liquid film and the line 18 to the intermediate portion are introduced. Trapped by droplets sprayed through. The liquid capturing the fine powder is circulated from the bottom of the apparatus through the liquid circulation pump 16 and the cooler 17 to the combustion furnace again through the line 15. Part of the circulating fluid is in the line
It is stored in a waste liquid drum 20 through 19. Such a combustion processing apparatus is disclosed in Japanese Patent Application Nos. 63-218389 and 63-284930.
It is described in the specification.

If necessary, a flammable gas is introduced into the line between the toxic exhaust gas source and the flashback prevention device through a line 21, and oxygen or air as a supporting gas is supplied to the combustion burner 12 through a line 22. Introduced through. To the exhaust gas supply line 11 to the combustion burner, a nitrogen gas line 23 is connected via a valve 25 and a line 27, and a water supply line 24 is connected via a valve 26 and a line 27. A mixture of water and water flows through the exhaust gas supply line 27 in the combustion burner nozzle. By flowing the mixture of water and nitrogen gas through the combustion burner nozzle, the burner nozzle can be cleaned.

In the present invention, as described above, the ejector 28 that ejects the pressurized driving gas a is provided in the line 11 that reaches the burner 12 of the combustion processing apparatus 3, and the exhaust gas is mixed from the ejector with the cylinder gas as a mixed gas. Take it out and send it to burner 12.

This e-sector 28 is similar to a commonly-used e-segmenter, and includes a nozzle portion 29, a suction chamber portion 30, and a diffuser portion 31, as shown in FIG. Suction chamber 34 when injected from 33
Is reduced, exhaust gas b is sucked, and the two pass through the diffuser 35 while being vigorously mixed. When the exhaust gas that has passed through the ejector in this way is introduced into the combustion burner 12 for combustion treatment, even if a pressure fluctuation occurs in the combustion furnace of the combustion processing device, the transmission of the pressure fluctuation is blocked by the ejector 28, and the ejector 28 is blocked. It is not transmitted upstream from 28.

As the driving gas in the ejector 28, various gases such as nitrogen, hydrogen, methane, and propane are used. The pressure of the driving gas is 2 to 15 times the outlet pressure of the diffuser,
The pressure is preferably 3 to 10 times, and the outlet pressure of the diffuser is 1 to 10 times, preferably 1 to 5 times the pressure of the exhaust gas to be sucked.

(Effect of the Invention) As described above, according to the present invention, a pressure generated in a combustion furnace is obtained by extracting a mixed gas with an ejector driving gas through an ejector upstream of a burner of the combustion furnace and introducing the mixed gas to the combustion furnace. The transmission of the fluctuations to the upstream side of the combustion furnace is blocked by the ejector portion to prevent the fluctuations from being transmitted to the toxic exhaust gas source. Therefore, according to the present invention, since the pressure condition does not fluctuate at all in the semiconductor manufacturing apparatus which is a toxic exhaust gas generation source, stable operation can be performed in the semiconductor apparatus.

[Brief description of the drawings]

FIG. 1 is a system diagram of an apparatus for performing the method of the present invention, and FIG. 2 is a longitudinal sectional view of the same ejector. 1. Toxic exhaust gas source 2. Adsorption treatment device 3. Combustion treatment device 7,8 Switching valve 12 Burner 16 Liquid circulation pump 28 Ejector 33 Nozzle 34 Suction Chamber 35: Dufuser a: Drive gas b: Toxic exhaust gas

──────────────────────────────────────────────────続 き Continuing on the front page (72) Norio Iwamoto, Inventor 63-2 Higashikawashima-cho, Hodogaya-ku, Yokohama, Kanagawa, Japan (72) Koji Kawai 6-7-35 Kita-Shinagawa, Shinagawa-ku, Tokyo Inside Sony Corporation ( 72) Inventor Hideto Ishikawa 6-35, Kita-Shinagawa, Shinagawa-ku, Tokyo Sony Corporation (72) Inventor Yoshifumi Mori 6-35, Kita-Shinagawa, Shinagawa-ku, Tokyo Inside Sony Corporation (56 References JP-A-53-30025 (JP, A) (58) Fields investigated (Int. Cl. ⁶ , DB name) F23G 7/06

Claims (1)

(57) [Claims] 1. A toxic exhaust gas from a toxic exhaust gas generating source is sucked into an ejector from which a pressurized driving gas has been ejected, and is taken out from the ejector as a mixed gas with the driving gas, and is introduced into a combustion furnace. A method of burning a burner, wherein a flashback preventing device is not interposed between the ejector and the combustion furnace, wherein a pressure fluctuation of the combustion furnace is prevented from being transmitted to a toxic exhaust gas generation source. Method.