Regarding high urea content in a liquid solution (aqueous solution)
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May I ask what specific effects does a high urea level in the coolant have on medium and low pressure systems? This post was last edited by lxq700918 on 2009-4-1 12:57.]
Low-pressure loads result in high loads and high ammonia consumption. If it exceeds 2%, check whether the vapor separator is damaged.
Regarding the reasons for high liquid level in one of the evaporators: First, there may be leaks at the location where steam is introduced into the upper tube sheet. Second, it’s possible that the cover on the separation section has fallen off; this should be checked. Third, if it’s a three-stage evaporation process, the effectiveness of the flash washing step should be examined. Fourth, the liquid level in the next stage of the evaporator might be too high. These are my personal opinions; I welcome any feedback from others.
The main reason for the high urea content in the liquid stream is severe liquid entrainment in the gas phase of the evaporation separator; this issue requires close attention. The main impacts are as follows: First, it leads to a high urea content in the ammonium carbamate solution, resulting in high urea levels in the solution that enters the urea hydrolysis and desorption system. This increases the load on the hydrolysis system and may even cause the urea content in the hydrolysis waste liquid to exceed the specified limits. Secondly, an excessively high urea content in the primary solution may lead to high urea levels in the secondary and tertiary solutions, which hinders the washing and absorption of ammonia and carbon dioxide from the first and second gas streams by the medium- and low-pressure absorption system; in severe cases, it even affects the efficiency of this washing and absorption process. This post was last edited by lxq700918 on 2009-4-1 20:36.]
What the original poster wants to know is whether it’s the reason for high urea levels in the fluid, or what impact high urea levels in that fluid have on medium and low pressure systems
This post was last edited by lxq700918 on 2009-5-29 at 13:46. It has a significant impact on the operation of the absorption tower; due to the high boiling point of urea, the temperature of the liquid exiting the absorption tower is high, resulting in poor absorption efficiency. The medium-pressure venting is unstable – if this temperature is too high, it is necessary to reduce the amount of urea used. If the liquid from the first stage and that from the second stage do not mix, things are fine: the liquid from the first stage can be used for hydrolysis, while the liquid from the second stage can be used as feed for the second circulation and cooling system