Production plant with polycrystalline silicon reduction furnaces and operation method

Abstract

The invention provides a production plant with a plurality of polycrystalline silicon reduction furnaces and an operation method. The production plant comprises the polycrystalline silicon reduction furnaces, a cooler, a set of Venturi injection device, a set of automatic control system and a plurality of material pipelines; inlet pipelines of the reduction furnaces are all connected with a mainfeeding pipeline, and outlet pipelines are connected with a tail gas reclaiming pipeline and a recycled material pipeline which can be switched through the automatic control system; the recycled material pipeline is connected to the Venturi injection device through the cooler; and the Venturi injection device is arranged at the front end of the main feeding pipeline. When a reaction starts, the outlet pipelines of the furnaces are communicated with the recycled material pipeline, reaction tail gas from the recycled material pipeline is cooled by the cooler, then enters the Venturi injection device, and finally enters the main feeding pipeline after being mixed with fresh feed gas; after the conversion rate reaches 15% to 20%, the outlet pipelines of the furnaces are switched to be connected to the tail gas reclaiming pipeline by the automatic control system, and then the reaction tail gas enters the follow-up tail gas treatment procedure.

Description

technical field [0001] The invention belongs to the technical field of polysilicon production, in particular to a production device and an operation method of a plurality of polysilicon reduction furnaces proposed for the reduction section of trichlorosilane. Background technique [0002] At present, the main process technology for polysilicon production at home and abroad is the improved Siemens method. The core step of this process technology - the reduction reaction of trichlorosilane is carried out in the polysilicon reduction furnace: firstly, high-purity trichlorosilane and hydrogen are mixed in proportion and then passed into the polysilicon reduction furnace, and then at a certain temperature (1080°C ~ 1150°C) and under pressure, the deposition reaction is carried out on the energized high-temperature silicon core to generate polysilicon; among them, the single furnace (single polysilicon reduction furnace) conversion rate of the key reactant component trichlorosilan...

AI Technical Summary

Problems solved by technology

First, because the reactants need to be heated in the reduction furnace, in order to prevent the heated gas from leaving the reduction furnace without reacting, the feed flow rate of the reactants is generally low, resulting in very weak turbulence of the reactants in the furnace, and the mixed It is very uneven, which affects the reaction rate and conversion rate; secondly, because the single-pass conversion rate of the reaction is very low, the reaction tail gas containing a large amount of raw material gas needs to be processed in the subsequent separation and purification section, and such a process is bound to increase production cost

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