Silicon powder drying electric heating device for polycrystalline silicon photovoltaic industry and use method thereof

Abstract

The invention belongs to the technical field of silicon powder drying, and particularly relates to a silicon powder drying electric heating device for the polycrystalline silicon photovoltaic industry and a use method thereof. The silicon powder drying electric heating device comprises a vertical silicon powder tank, and a plurality of electric heating radiation heating pipe fittings are evenly and vertically connected to the top of the vertical silicon powder tank in an inserted mode; the bottoms of the electric heating radiation heating pipe fittings extend into the vertical silicon powder tank and are used for drying silicon powder in the tank, and the vertical distances from the bottoms of the electric heating radiation heating pipe fittings to the inner wall of the vertical silicon powder tank under the electric heating radiation heating pipe fittings are equal. According to the silicon powder drying electric heating device for the polycrystalline silicon photovoltaic industry and the use method thereof, the multiple electric heating radiation heating pipe fittings are vertically installed on the vertical silicon powder tank, the vertical distances between the bottoms of the electric heating radiation heating pipe fittings and the inner wall of the vertical silicon powder tank under the electric heating radiation heating pipe fittings are equal, uniform heating of the silicon powder in the tank is achieved, the silicon powder drying efficiency is greatly improved, energy waste is reduced. The problems that raw material industrial silicon powder in a type drying tank of a steam jacket in the prior art is low in heat efficiency, uneven in heating and not easy to completely discharge water are solved.

Description

technical field [0001] The invention relates to the technical field of silicon powder drying, in particular to an electric heating device for drying silicon powder used in the polysilicon photovoltaic industry and a method for using the same. Background technique [0002] At present, in the field of polysilicon photovoltaics, the production of polysilicon adopts the Siemens polysilicon process, and one of the raw materials is trichlorosilane, which is synthesized by gas HCL and industrial silicon powder in a synthesis furnace. Silicon powder is a completely dry silicon powder raw material. [0003] At present, the polysilicon industry has been using the steam jacket type in the silicon powder drying process to dry the raw material industrial silicon powder in the tank (such as Figure 4 ), raw material industrial silicon powder generally contains 0.06% to 0.1% water before use, and the internal water must be completely dried before entering the next process. Since the diamet...

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Problems solved by technology

[0003] At present, the polysilicon industry has been using the steam jacket type in the silicon powder drying process to dry the raw material industrial silicon powder in the tank (such as Figure 4 ), raw material industrial silicon powder generally contains 0.06% to 0.1% water before use, and the internal water must be completely dried before entering the next process. Since the diameter of the vertical silicon powder tank is generally designed to be about 3 to 4 meters, before Drying industrial silicon powder heats the tank wall through the steam in the jacket, and then the tank wall transfers heat to the internal industrial silicon powder. First, the thermal efficiency is very low. Second, the heating of the silicon powder is very uneven. Completely drain, according to statistics, there will be about 0.01%~0.02% water in the industrial silicon powder that cannot be drained, and finally flows into the reaction synthesis furnace. If the industrial silicon powder contains a small amount of water, it will be harmful to trichlorosilane The synthesis of polysilicon and the entire polysilicon production system cause great harm, mainly in the following points:

[0004] 1. Corrosion of pipelines and equipment, which is the main cause of leakage; 2. It will react to form silica solid impurities and block pipelines; 3. Reduce the efficiency of synthesizing trichlorosilane; 4. Increase production costs; 5. Impact The quality of polysilicon products, so it is very important to completely dry the water in industrial silicon powder

[0005] In order to solve the problems of low thermal efficiency, uneven heating and difficult water discharge in the raw material industry silicon powder in the steam jacket type drying tank in the past, this application proposes a silicon powder drying electric heating device for polysilicon photovoltaic industry and its Instructions

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