Dry recovery system and method of reduction tail gas produced in polysilicon production process

Abstract

The invention discloses a dry recovery system and a dry recovery method of reduction tail gas produced in a polysilicon production process. The system comprises a leaching tower, an absorption system, an absorption device, and a first filtering device. The absorption system is used for carrying out an absorption treatment upon leached reduction tail gas, such that chlorosilane and hydrogen chloride in the leached reduction tail gas can be removed, and hydrogen can be obtained. An adsorbentused for carrying out an absorption treatment upon the hydrogen is arranged in the absorption device, such that residual chlorosilane and hydrogen chloride in hydrogen can be further removed by adsorption. The first filtering device is used for filtering the hydrogen processed through the absorption treatment, such that high-purity hydrogen is obtained. A ceramic filter core is arranged in the first filtering device. According to the dry recovery system provided by the invention, a gas filtering device provided with the ceramic filter core is adopted. The filtering device has excellent properties of high-temperature resistance and corrosion resistance. Therefore, no influence is caused upon polysilicon product quality.

Description

technical field [0001] The invention relates to the technical field of polysilicon production technology, and more specifically, the invention relates to a dry recovery system and method for reducing tail gas generated in the polysilicon production process. Background technique [0002] More than 85% of the process technology of polysilicon projects in my country at this stage belongs to Siemens process technology. In the process of this process, there are many systems that need to carry out gas filtration. Specifically: hydrogenation of silicon tetrachloride to produce trichlorosilane system, trichlorosilane synthesis system, reduction tail gas dry recovery system, etc. [0003] At present, the filters generally used are cloth bag filters, but in the production process, it is found that the cloth bag filters have the following disadvantages: [0004] 1. The bag filter has poor high temperature resistance. Especially in the synthesis system of trichlorosilane and the hydro...

AI Technical Summary

Problems solved by technology

[0004] 1. The bag filter has poor high temperature resistance

Especially in the synthesis system of trichlorosilane and the hydrogenation of silicon tetrachloride to produce trichlorosilane, it was found that the bag filter was very prone to damage, resulting in a serious decline in the filtering effect and eventually causing blockage of the subsequent system;

[0005] 2. The bag filter is easily damaged, which will cause a large increase in the amount of dust in the gas, and eventually cause a sharp decline in product quality;

[0006] 3. Cloth bag filter is expensive. At present, the imported filter material is converted to the finished filter bag, and the price per square meter reaches more than 1,000 yuan;

[0007] 4. The filter material of the cloth bag filter has poor corrosion resistance, and at the same time, the support is easy to corrode during the maintenance process, resulting in difficult maintenance and high maintenance costs

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