While enhancing capacities of Ammonia and Urea Plants during revamp, Urea Plant I LP condenser was replaced with a bigger one and the removed condenser of Urea Plant I was installed in parallel to the LP condenser in Urea Plant II. After that, either of one condenser only was coming in operation at a time. This aspect resulted in higher LP loop pressures with vent valve in full open condition, which became a bottleneck for the plant operation. This case study deals with the operational problems faced, various modifications implemented, changing in configuration, layout etc and also experiments were done to find the root cause.
Finally, the problem was solved successfully.