Flushing device and method for second-stage evaporation separator in urea production system

Abstract

The invention discloses a flushing device and method for a two-stage evaporation separator of a urea production system. The flushing device adopts the structure that a ring-shaped flushing water pipe (3) is arranged at the top of the separator (1) and is connected with a flushing water pipeline (32); a plurality of flushing water holes (31) facing towards the inner wall of the top part of the separator (1) are uniformly formed in the pipe wall of the ring-shaped flushing water pipe (3); and a longitudinal flushing water pipe (4) used for flushing a longitudinal part of a vapor phase outlet pipe (2) is arranged at the vapor phase outlet pipe (2) connected with the separator (1), as well as a horizontal flushing water pipe (5) for flushing the horizontal part of the vapor phase outlet pipe (2) and an ach-direction flushing water pipe (6) for flushing the arc-shaped part of the vapor phase outlet pipe (2). The flushing device and method can effectively avoid storage of biuret, prolongs the running period of the equipment, increases the evaporation load, and improves the product quality.

Description

technical field

[0001] The invention relates to a flushing device and method for a second-stage evaporation separator in a urea production system, in particular to a device and method for flushing biuret and other substances accumulated in the second-stage evaporation separator. Background technique

[0002] The urea synthesis reaction solution is subjected to gas stripping, decompression heating and decomposition cycles, and after being separated from unreacted substances, a relatively pure urea aqueous solution is obtained, wherein the content of urea is 70% to 75% (mass number), NH 3 and CO 2 The sum of the content is about 1%, and the urea aqueous solution also contains a large amount of water, a small amount of ammonia and carbon dioxide. Therefore, it must be further concentrated into molten urea with very little water content through the evaporation process, so that its concentration can reach more than 96%, and then sent to the granulation system for granulation. I...

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