Vacuum process for cracking dimethyl dichlorosilane hydrolysate

Abstract

The invention provides a vacuum process suitable for cracking organic silicon hydrolysate. After vacuum gas passes through a heat exchanger A, a liquid phase enters a collecting tank, and a gas phase and a part of entrained liquid phase enter a hydrocyclone separation tank; the liquid phase separated by the hydrocyclone separation tank is returned to the collection tank again, and the gas phase enters a Roots vacuum unit; and after being primarily compressed by the Roots vacuum unit, the gas enters a screw vacuum unit to be further compressed after passing through a heat exchanger B and a buffer tank, and finally, the gas is completely discharged into an absorption tower. The vacuum gas is condensed and compressed step by step through multi-stage heat exchange, so that components with higher boiling points in the gas are ensured to be fully liquefied, the load of a vacuum unit is greatly reduced, and the high vacuum requirement of cracking dimethyl dichlorosilane hydrolysate is met; and components with higher freezing points are not crystallized, and device system faults caused by blockage of pipeline facilities of a vacuum unit due to crystallization are avoided.

Description

technical field [0001] The invention belongs to the technical field of chemical production, and in particular relates to a vacuum process suitable for cracking dimethyldichlorosilane hydrolyzate. Background technique [0002] Dimethyldichlorosilane hydrolyzate is cracked under high vacuum and high temperature conditions to produce dimethylsiloxane mixed rings ("DMC" for short), and a large number of low-boiling substances (mainly water, hexamethyl Dicyclotrisiloxane (D3 for short), octamethylcyclotetrasiloxane (D4 for short), etc.), are collected by the supporting vacuum unit and discharged to the external system to maintain the cracking system in a high vacuum environment. Since the normal pressure freezing point of D3 in such low boiling point substances is only 64°C, under the environment of absolute pressure of 10kPa, the boiling point of water is 45.8°C, and the boiling point of D3 is only 67°C. In a low-temperature vacuum environment, it is very easy to cause equipmen...

AI Technical Summary

Problems solved by technology

In a low-temperature vacuum environment, it is very easy to cause equipment blockage or material liquefaction to damage the machine seal and other faults; there are disadvantages such as frequent replacement of liquid rings, low pumping capacity, frequent maintenance, and low level of automation control, which need further optimization.

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