Silicon tetrachloride hydrogenation reactor introducing microcirculation distribution structure

Abstract

The invention discloses a silicon tetrachloride hydrogenation reactor introducing a microcirculation distribution structure, comprising a lower tapered section, a reaction section, a reducing section, a gas-solid separating section and an end enclosure, wherein a heat exchange pipe bundle is arranged in the reaction section and comprises the structure that heat exchange tubes with the same diameter are uniformly distributed around a center heat exchange tube; and the diameter of the center heat exchange tube is greater than that of the heat exchange tubes distributed around; the heat exchange tubes are dual-layer metal conduits; heat-conducting oil flows in clamping sleeves of the heat exchange tubes; and the hollow conduits are in direct contact with particles on a bed layer inside a fluidized bed. The microcirculation distribution structure is introduced into the silicon tetrachloride hydrogenation reactor; the hollow conduits are in direct contact with particles on the bed layer inside the fluidized bed; the diameters of the hollow conduits are far smaller than the diameter of a fluidized bed reactor; gas has higher flow speed in the hollow conduits to drive solid particles to accelerate the movement so as to form an internal circulation; the miniature circulating fluidization can be formed in a bear area of each heat exchange tube, benefits the crushing of air bubbles in the gas-solid reaction, simultaneously reduces the phenomenon of gas backmixing and improves the per pass conversion of silicon tetrachloride to about 32 percent.

Description

technical field [0001] The present invention is a silicon tetrachloride hydrogenation reactor which introduces a microcirculation distribution structure. The reactor is a fluidized bed reactor, which is mainly used in the formation of trichloride from silicon tetrachloride, silicon powder and hydrogen under the action of a certain catalyst. Chlorosilane reaction. Background technique [0002] Polysilicon is the main raw material for manufacturing integrated circuit substrates, solar cells and other products, and is widely used in the semiconductor industry. At present, the mainstream production process of polysilicon in Chinese enterprises is the improved Siemens method, and its typical process is as follows: Synthesize hydrogen chloride with chlorine and hydrogen, synthesize trichlorosilane at a certain temperature with hydrogen chloride and industrial silicon powder, and simultaneously generate silicon tetrachloride and other by-products. product, and then carry out recti...

AI Technical Summary

Problems solved by technology

The fixed bed reactor has the advantages of simple structure, small back mixing, and small loss of catalyst, but it has obvious disadvantages, such as poor heat transfer effect, inconvenient catalyst replacement and regeneration, and large space required when production requirements are large. Continuous production cannot be carried out, and comprehensive energy consumption is high

The fluidized bed reactor can solve these problems very well and realize the continuous production of the hydrogenation process of silicon tetrachloride. In recent years, major domestic polysilicon enterprises have conducted preliminary research on the application of the fluidized bed reactor to the hydrogenation of silicon tetrachloride, but it has not yet been realized. Industrial production

Domestic patent CN 201605166 reports an ebullating bed reactor applied to the hydrogenation of silicon tetrachloride, wherein the ebullating bed reactor is a kind of fluidized bed reactor, but there are certain problems in the ebullating bed structure hydrogenation reactor, such as the use of low-speed flow The number of state bubbles and the degree of back-mixing are large, and the single-pass conversion rate is limited

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