Combustion type waste gas treatment system

Abstract

A combustion type waste gas treatment system capable of oxidatively decomposing a hazardous combustible waste gas while heating efficiently with a structure which allows the waste gas to mix with an auxiliary burning gas efficiently without the occurrence of backfire in a waste gas inlet pipe. The combustion type waste gas treatment system has a burner part and a combustion chamber. Combustion flames are formed to extend from the burner part toward the combustion chamber, and a combustible waste gas is introduced into the combustion flames from waste gas inlet pipes thereby oxidatively decomposing the waste gas. A flow velocity accelerating device makes the flow velocity of the combustible waste gas flowing through the waste gas inlet pipe higher than the burning velocity of the combustible waste gas.

Description

[0001] This application is a divisional of U.S. application Ser. No. 09 / 962,117, filed Sep. 26, 2001, now allowed.BACKGROUND OF THE INVENTION [0002] The present invention relates to a combustion type waste gas treatment system for combustion-treating hazardous and combustible waste gases discharged from semiconductor manufacturing systems, liquid crystal panel manufacturing systems, etc. More specifically, the present invention relates to a combustion type waste gas treatment system for combustion-treating hazardous and combustible waste gases containing, for example, silane gas (SiH4) or a halogen-containing gas (NF3, CF3, SF6, CHF3, C2F6, CF4, etc.), or hardly decomposable waste gases. [0003] A conventional combustion type waste gas treatment system has a burner part and a combustion chamber provided at the downstream side of the burner part. An auxiliary burning gas is supplied into the burner part and burned to form flames, and a hazardous and combustible waste gas introduced in...

AI Technical Summary

Benefits of technology

[0007] An object of the present invention is to provide a combustion type waste gas treatment system capable of oxidatively decomposing a hazardous combustible waste gas by heating efficiently with a structure which allows the waste gas to mix with the auxiliary burning gas efficiently without the occurrence of backfire in the waste gas inlet pipe and permits the waste gas to stay in the combustion chamber for a lengthened period of time and which facilitates heating of the waste gas.

[0027] As stated above, at the time of extinguishing the flames, the oxygen gas supply valve and the fuel gas supply valve are closed to stop the supply of the oxygen gas and the fuel gas. Thereafter, the oxygen gas supply line and the fuel gas supply line are supplied with the non-combustible gas as a purge gas in an amount equal to the amount of oxygen gas and fuel gas which would otherwise be supplied. Consequently, it is possible to eliminate variations in the flow rate. Thus, it becomes possible to prevent the occurrence of backfire at the time of extinction of flames.

Problems solved by technology

Conventional waste gas treatment systems of the type described above are not satisfactory in terms of the resident time of waste gas and the scheme of heating waste gas.

In the above-described combustion type waste gas treatment system, because the waste gas is combustible, there is a danger of backfire spreading into a waste gas inlet pipe for introducing the combustible waste gas into the burner part, which may cause devices to be broken.

There is also a danger of pressure rise due to abnormal combustion, which may also cause breakage of devices.

Further, there is a danger that fuel gas or oxygen gas may leak from the fuel gas supply line or the oxygen gas supply line.

When hydrogen gas is used as fuel gas in particular, leakage of hydrogen gas and oxygen gas may cause an explosion.

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