Falling-film stripper for carbamate decomposition

Abstract

A stripper (S N ) for carbamate decomposition and ammonia plus carbon dioxide recovery from a urea solution (U) is realized with a shell-and-tube heat exchanger, where a liquid falling film of urea solution and a counter-current gaseous flow of a stripping medium fed to a bundle of surface-heated tubes (6); the stripping medium such as carbon dioxide is distributed into the tubes (6) by a plurality of gas risers (32); the gas risers are preferably associated to a perforated tray (30) in the bottom chamber (11) of the stripper. Revamping of a conventional CO 2 stripper is also disclosed.

Description

Technical field [0001] The present invention involves a diaphragm and carbon dioxide of ammonia and carbon dioxide from the outflow of ammonia and from the influx of the synthetic urea reactor.Specifically, the invention involves a gaseous steam -lifted medium such as carbon dioxide, which is distributed in the steam pipe. Background technique [0002] In the production process of urea, it is well known to supply the outflow of the reactor to the steam Tower. In the steam Tower, the amino -aminate is decomposed into ammonia and carbon dioxide with the function of heating and anti -extract. [0003] The diaphragm -type steam tower is basically a vertical tube shell heat exchanger, including the top tube box and the bottom pipe box, which uses the tube to flow through the tube.Provide the reactor out of the pipe box; supply the steam -lifted medium to the tube box in the lower part, and collect the concentrated urea solution from the tube.The gas phase including steam -lifted mediu...

AI Technical Summary

Problems solved by technology

Existing stripper could not support increased flow rate due to flooding issues

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