Dust removal process and system for trichlorosilane production

Abstract

The invention provides a dust removal process and a system for trichlorosilane production. A dust containing reaction gas from a fluidized bed firstly enters into a venturi scrubber for scrubbing, a washed gas phase and a washed liquid phase are separated in a gas-liquid separation tank, the gas enters into a scrubbing tower from a gas inlet on the lower portion of the scrubbing tower, a liquid enters into the scrubbing tower from a liquid inlet on the lower portion of the scrubbing tower, the gas which is subjected to scrubbing purification is discharged from a gas outlet on the upper portion of the scrubbing tower, the gas discharged out of the scrubbing tower is subjected to condensation by a condenser, a part of condensate liquid serving as a scrubbing liquid of the scrubbing tower enters into the scrubbing tower again from the top, the other part of the condensate liquid is sent to a rectification device, and a slag slurry which contains high concentration silica powders, metal chlorides and high-boiling residues is discharged from a slurry port. According to the dust removal process and the system for the trichlorosilane production, the reaction gas which is subjected to cyclone dust removing is further processed, the high-boiling residues, the metal chlorides and a trace of refine silica powders contained in the reaction gas are removed by the device, when the reaction gas enters into the condensation system, pipelines and equipment can not be blocked, pollutions of the metal chlorides and high-boiling residues trichlorosilane are reduced, and the continuous and stable operation of the device is guaranteed.

Description

technical field [0001] The invention relates to a dust removal system for the outlet gas of a fluidized bed reactor in a trichlorosilane synthesis unit and a cold hydrogenation unit (hydrogenation of silicon tetrachloride). Background technique [0002] As the main raw material for manufacturing integrated circuit substrates, solar cells and other products, polysilicon is an important cornerstone for the development of information industry and new energy industry. At present, the domestic and foreign production of polysilicon mainly adopts the improved Siemens method, which consumes 19 to 24 tons of trichlorosilane for every ton of polysilicon produced, and at the same time produces 15 to 20 tons of silicon tetrachloride and tetrachloride. Silicon easily reacts with water to generate hydrogen chloride, which is directly discharged and seriously pollutes the environment. [0003] As the main raw material for polysilicon production, trichlorosilane is currently produced by ga...

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Problems solved by technology

[0007] Another object of the present invention is to provide a dust removal system for the production of trichlorosilane to solve the problem of condenser blockage and ensure the smooth discharge of the tower kettle

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