Cooling structure for chassis of reduction furnace

Abstract

The invention discloses a reduction furnace chassis cooling structure, relates to the technical field of polycrystalline silicon production equipment, and mainly aims to provide a reduction furnace chassis cooling structure capable of uniformly discharging tail gas, ensuring more uniform distribution of a temperature field and a velocity field in a reduction furnace and enabling growth rates of silicon rods at different positions to tend to be balanced. According to the main technical scheme, the chassis cooling structure of the reduction furnace comprises a chassis, and the chassis is provided with a cooling pipeline and a plurality of exhaust holes; the chassis sleeve comprises a water inlet pipeline, a tail gas pipeline and a drainage pipeline, the tail gas pipeline is sleeved with the water inlet pipeline, the water inlet pipeline is connected to the cooling pipeline, the cooling pipeline is connected to the drainage pipeline, and one end of the tail gas pipeline is connected to the multiple exhaust holes; the first gas pipe communicates with the other end of the tail gas pipeline, and the first water pipe sleeves the first gas pipe. The device is mainly used for discharging and cooling the tail gas of the reduction furnace.

Description

technical field [0001] The invention relates to the technical field of polysilicon production equipment, in particular to a bottom cooling structure of a reduction furnace. Background technique [0002] At present, polysilicon production enterprises mainly use the modified Siemens method to manufacture polysilicon. The production process of this method is to synthesize trichlorosilane with hydrogen chloride and silicon powder at a certain temperature, and then purify the trichlorosilane fine filling, and the purified high-purity trichlorosilane After the chlorohydrogen silicon and hydrogen are mixed in proportion, they are passed into the polysilicon reduction furnace at a certain temperature and pressure, and the vapor deposition reaction is carried out on the electrified high temperature silicon core to generate polysilicon, and the unreacted exhaust gas is discharged from the exhaust gas outlet on the furnace plate. , enter the next process, when manufacturing polysilicon...

AI Technical Summary

Problems solved by technology

[0003] The inlet nozzle and the tail gas outlet of the existing reduction furnace are all located on the furnace pan of the reduction furnace, which leads to the following disadvantages: first, it is easy to cause part of the feed mixture gas to take a short circuit and be directly discharged from the tail gas outlet with low pressure, which reduces the polysilicon. Conversion rate

Second, due to the high speed and low temperature of the feed gas at the gas inlet, a concentration gradient and a temperature gradient must be generated in the vertical direction of the reduction furnace, resulting in a low deposition reaction rate of polysilicon at the root of the electrode, and at the same time Since the upward flow of gas also tends to drive the polysilicon on the surface of the electrode to move upwards, the combined effect of the two makes the growth rate of the lower part of the silicon core slower, resulting in a thicker upper part of the silicon core and thinner roots, which is not conducive to the safe and stable production of polysilicon.

Third, the relevant structure of the reduction furnace design leads to high gas velocity at the inlet of the reduction furnace, while the gas velocity at the top of the reduction furnace is low, resulting in a backflow dead zone at the top of the reduction furnace, which reduces the output of polysilicon

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