Device and method for slagging clogging resistance of vaporization reboiler in cold hydrogenation technology

Abstract

The invention discloses a device for slagging clogging resistance of a vaporization reboiler in a cold hydrogenation technology. The device comprises a slagging pipe and a flushing fluid input pipe. The vaporization reboiler is provided with a slagging port. The slagging pipe is communicated with the slagging port, and is used to remove slag of the vaporization reboiler. The slagging pipe is provided with a first valve and a second valve. The first valve is arranged on the slagging pipe between the second valve and the slagging port. The output end of the flushing fluid input pipe is communicated with the slagging pipe between the first valve and the second valve. The flushing fluid input pipe is provided with a third valve. The device prolongs operation time of a cold hydrogenation system to the largest extent while new devices are not added in the cold hydrogenation technology, so that problems that the slagging pipe of the vaporization reboiler is blocked in high temperature and high pressure are solved, and operation period time of the cold hydrogenation system is prolonged.

Description

technical field [0001] The invention belongs to the technical field of polysilicon, and in particular relates to a device and method for removing slag and preventing clogging of a vaporization reboiler in a cold hydrogenation process. Background technique [0002] At present, in the polysilicon industry, in order to reduce production costs, most enterprises have begun to use cold hydrogenation technology to process silicon tetrachloride produced in polysilicon production. A large amount of gaseous silicon tetrachloride needs to be used in the production of cold hydrogenation. The gaseous silicon tetrachloride contains about 0.5% metal chloride and micro-silica impurities. With the increase of the vaporization amount of silicon tetrachloride in the vaporization reboiler , so that the solid content of silicon tetrachloride in the vaporizing reboiler gradually increases, wherein, the impurity content of metal chlorides such as iron, aluminum, calcium, etc. is about 5%, and the ...

AI Technical Summary

Problems solved by technology

[0003] Since the slag discharge pipeline of the reboiler of the vaporizer contains as much as 5% to 20% of metal chloride impurities in the silicon tetrachloride discharged, most enterprises discharge such substances together with part of the silicon tetrachloride, but after the discharge is completed , the temperature of the slag discharge pipeline is high, causing the remaining impurities to adhere to the wall of the slag discharge pipeline after the vaporization of silicon tetrachloride, which is easy to cause blockage of the slag discharge pipeline. The sharp increase of the solid content in the vessel causes the efficiency of the vaporization reboiler to decrease, which in turn leads to the shutdown of the cold hydrogenation system, and it is difficult to clear the blockage of the slag discharge pipeline. The slag slurry contains boron, phosphorus and other flammable and explosive substances, which are very easy to catch fire , is not conducive to safe production

[0004] At present, there is no technical solution related to polysilicon cold hydrogenation technology, especially the technical solution to prevent the clogging of chlorosilane slag discharge pipeline under high temperature and high pressure.

Images