Device and method of continuously separating solid-liquid phases in caprolactam distilled heavy residual liquid

Abstract

The invention discloses a device and a method of continuously separating solid-liquid phases in a caprolactam distilled heavy residual liquid. The device comprises a settler. A feed inlet is formed in one side of the settler while an overflow port is formed in the other side, and a slagging port is formed in bottom; the overflow port is connected to a clear liquor middle tank, and the slagging port is connected to a residual clear liquor tank; and the clear liquor middle tank is connected to a caprolactam step through a pipeline and a pump, and the clear liquor middle tank is connected to a caprolactam process water pipeline. By using caprolactam process water to clean and dilute the clear liquor and residues, continuous separation of caprolactam and low polymers in the caprolactam distilled heavy residual liquid and cyclic utilization of the caprolactam process water are realized.

Description

technical field

[0001] The invention belongs to the technical field of chemical industry and relates to the production of caprolactam, in particular to a device and method for continuous separation of solid and liquid phases in the heavy raffinate of caprolactam distillation. Background technique

[0002] The caprolactam distillation process is the last step in caprolactam refining. In the distillation process, high vacuum operation is used to reduce the boiling point of caprolactam, which can avoid the polycondensation of caprolactam by high heat. At the same time, alkali is added to the distillation feed liquid to neutralize a small amount of organic acid that may exist to form stable salts, so that it can be separated from caprolactam in distillation. , reduce the volatile alkali content of the product. However, local overheating inevitably exists in the heater tubes heated by steam, and the existence of caustic soda and moisture that are conducive to the polymerizatio...

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