Method and apparatus for exhaust gas treatment in chemical vapor deposition / chemical gas phase penetration processes

Abstract

The invention discloses a kind of industrial CVI / CVD process tail gas processing method and device, which is mainly applied to the process of tail gas in industrial production or other vacuum device. The invention uses mechanism pump oil circulating sediment technology, steam and tail gas reaction and process technology, and tail gas process product separating technology to process the tail gas through oil filter and solid filter, thus the gas, liquid and solid product after processed by tail gas process satisfy the demands of discharge. The invention upgrades the stability of mechanism pump; the tail processing device has no noise, long lifespan, low cost.

Description

technical field [0001] The invention relates to a chemical vapor deposition / chemical vapor infiltration (hereinafter referred to as CVD / CVI) process tail gas treatment method and equipment. It is suitable for the treatment of exhaust gas in the process of preparing continuous fiber toughened ceramic matrix composite materials, anti-oxidation coatings and various thin film materials by industrial CVD / CVI, and also suitable for the exhaust gas treatment of other vacuum equipment. Background technique [0002] The feed gas in the CVD / CVI process includes H 2 , Ar and metal organosilane, so the components of the tail gas include undecomposed metal organosilane, reaction product HCl, decomposition product tar, deposition product particles, carrier gas H 2 and diluent Ar. Undecomposed metal organosilane and reaction product HCl will produce highly corrosive hydrochloric acid gas when they meet with water in the air, so they cannot be directly discharged into the atmosphere. The...

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Problems solved by technology

There are two reasons for limiting the flow rate of exhaust gas treatment: one is that the exhaust gas with a large flow rate makes the pumping rate of the mechanical pump drop rapidly, and the mechanical pump with high pumping rate works alternately and it is very difficult to replace the pump oil and maintain it, which undoubtedly reduces the operating efficiency of the CVD / CVI equipment. Use efficiency; Second, the caustic soda solution used in the water ring pump has a strong saponification reaction with HCl. Large-volume tail gas treatment requires a large-volume water tank or increased wastewater discharge frequency to ensure the normal operation of the water ring pump, which undoubtedly increases the cost of the CVD / CVI process.

In addition, the noise pollution of the high pumping rate water ring pump required for large flow tail gas treatment is serious

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