Nozzle

Abstract

The invention provides a nozzle. The nozzle comprises a nozzle body and a floater, wherein a conical cavity which allows fluid circulation is formed inside the nozzle body; the floater comprises a floater body; a circulation gap from which the fluid flows out is formed by the outer circumferential surface of the float body and the inner circumferential surface of the cavity; the floater is movably arranged relative to the nozzle body in the direction of a connecting line of the inlet end of the cavity and the outlet end of the cavity and tends to move to the inlet end of the cavity; when the floater moves in the direction from the inlet end to the outlet end, the circulation gap is gradually enlarged. When the flow of the fluid entering the inlet end of the cavity is higher, the floater moves in the direction from the inlet end to the outlet end under the action of the impact force of the fluid, and the circulation gap is gradually enlarged, so that the flow speed is effectively decreased; when the flow of the fluid is lower, the circulation gap is smaller, so that the flow speed of the fluid flowing out of the circulation gap is guaranteed favorably, and the function of automatically regulating the flow speed by the nozzle according to the flow magnitude of the fluid is achieved.

Description

technical field [0001] The invention relates to a nozzle. Background technique [0002] In the field of polysilicon production, the reduction furnace is the core equipment for the production of polysilicon. The mixed gas mainly containing trichlorosilane and hydrogen enters the furnace cavity through the mixed gas nozzle, and the reaction is completed under high temperature and high pressure, and the formed silicon is deposited on the silicon core rod. . Generally, the gas velocity of the mixed gas nozzle can only change with the change of the gas volume. When the mixed gas flow rate is small, the flow velocity at the nozzle outlet is small, and the mixed gas cannot reach the top of the silicon rod, which affects the distribution of the thermal field in the furnace and causes the upper end of the silicon rod to be damaged. The local temperature is high, forming cauliflower-like polysilicon, and in severe cases, molten silicon phenomena such as burning flow occur. [0003] ...

AI Technical Summary

Problems solved by technology

Generally, the gas velocity of the mixed gas nozzle can only change with the change of the gas volume. When the mixed gas flow rate is small, the flow velocity at the nozzle outlet is small, and the mixed gas cannot reach the top of the silicon rod, which affects the distribution of the thermal field in the furnace and causes the upper end of the silicon rod to be damaged. The local temperature is high, forming cauliflower-like polysilicon, and in severe cases, melting silicon phenomena such as burn-off will occur

[0003] The nozzles in the prior art cannot adjust the flow rate according to the gas volume, so as to meet the problem of normal growth of polysilicon rods

Especially in the initial stage of the reduction furnace start-up, when the volume of the mixed gas is small, the flow rate of the gas ejected from the original fixed nozzle is small, which will cause the mixed gas to fail to reach the top of the silicon core, resulting in a high temperature on the upper part of the silicon core and burn-off Or sparking phenomenon, rough surface or even cauliflower-like appearance will appear in the middle and later stages, which greatly reduces the appearance quality of polysilicon, which is not conducive to product processing and sales

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