Drainage device capable of changing flow direction of carrier gas

Abstract

The invention belongs to the field of polycrystal casting units and particularly discloses a drainage device capable of changing the flow direction of carrier gas. The drainage device comprises a gasinlet part, a shunt part and a drainage part which are connected fixedly in sequence, wherein a gas inlet hole allowing the carrier gas to flow in is formed in the gas inlet part; a shunt cavity is formed in the shunt part; the drainage part comprises at least one drainage gas channel for changing the flow direction of the carrier gas; the gas inlet hole is communicated with the shunt cavity; a gas inlet of each drainage gas channel is communicated with the shunt cavity, and gas outlets are distributed in the same angular direction circumferentially. The drainage device is provided with a viewfield leading into an ingot furnace and drives the carrier gas to dispersedly blow different areas of the surface of liquid silicon, the contact are of the carrier gas and the surface of the liquid silicon is increased, and local area supercooling caused by the carrier gas and impurity formation promoted by the carrier gas are reduced; the carrier gas drives the liquid silicon to produce a rotating flow field, under the combined action of a natural convection flow field and the rotating flow field, impurity volatilization is promoted, local area enrichment of impurities in the liquid siliconis reduced, and radial electrical resistivity of crystals is distributed more uniformly.

Description

[0001] This application is a divisional application of a patent application with application number 201610082942.8, application date 2016-02-03, and titled a drainage device for changing the direction of carrier gas. technical field [0002] The invention relates to a drainage device, in particular to a drainage device for changing the flow direction of a carrier gas used in a polycrystalline ingot furnace, and belongs to the field of crystal growth equipment. Background technique [0003] The polycrystalline ingot furnace 10 is mainly composed of an infrared detector 16, a furnace body 11, a drainage device 12, a heat insulation cage 13, a heater 14, and a graphite platform 15, such as figure 1 shown. The drainage device 12 includes a graphite tube 123 , a fitting nut 121 and a flow guide tube 122 . The upper end of the guide tube 122 is provided with an external thread that matches the internal thread of the fitting nut 121, and the upper end of the guide tube 122 passes ...

AI Technical Summary

Problems solved by technology

In order to overcome the problems existing in the application of the existing drainage device: the carrier gas is concentratedly blown to a certain area on the surface of the liquid silicon, and the carrier gas takes away a large amount of heat from this area, causing the local supercooling of the liquid silicon in this area and promoting the liquid state. The nucleation and growth of impurities in silicon; the carrier gas does not form a circumferentially distributed carrier gas stress on the surface of liquid silicon, and it is difficult to form a swirling flow field in liquid silicon; the field of view leading to the ingot furnace in the drainage device is completely blocked. The state of the ingot furnace cannot be observed through the drainage device through the window, which is inconvenient for the furnace operator; the crystal measuring rod cannot be inserted into the ingot furnace through the drainage device, and the crystal growth rate is inconvenient to measure; the infrared detector cannot detect the state of the silicon material in the furnace , the automatic crystal growth process cannot be carried out normally

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