How to identify and locate the source of leakage when the ammonia content in the condensate at the urea plant exceeds the specified limits?
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How to identify and locate the source of leakage when the ammonia content in the condensate at the urea plant exceeds the specified limits?
In the case of a carbon dioxide stripping process, check the condensate from the high-pressure drum and the low-pressure drum, and then examine the condensate from the circulation heater as well as that from the first and second stages of evaporation. If ammonia levels are above the normal range in any of these areas, it indicates that there is a leak there! ! ! !
The shell side of the first and second stage evaporative heaters is heated by low-pressure steam, while the tube side contains the process medium. When such a device leaks, the shell-side pressure rises, it is difficult to achieve a high vacuum level, and the liquid outlet temperature drops. How can ammonia appear in the condensate?
Search all steam heaters, check all jacket insulations, examine all points where condensate/steam pipes (valves) are connected to the process medium, and verify whether the steam entering the workshop is of suitable quality – a solution can always be found. Ammonia cannot appear out of nowhere; it’s governed by the law of conservation of mass.
First, it is necessary to determine whether it is the process condensate or the steam condensate that has an excessive ammonia content. 1. If the ammonia content in the process condensate is above the limit, check the separation system ； 2. It’s a problem if the ammonia content in the steam condensate exceeds the limits; all steam heaters need to be checked, with particular attention paid to the ammonium methoxide condenser. It should be noted that if a valve at the connection between the flushing pipeline and the process pipeline leaks, it can also lead to an excessive ammonia level.
It would be best to check the ammonia content in your low-pressure or medium-pressure steam.