Overpressure issue in the gas phase pre-separation stage of the urea process
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Some time ago, the pre-separation gas phase experienced overpressure in our company’s aqueous solution full-circulation urea production plant, which caused the secondary air compressor to shut down and led to a temporary shutdown of the system. What do you think caused this?
"Pre-separation gas phase overpressure, secondary air compressor trips!" This phenomenon shouldn’t occur, right? I wonder which device for medium-pressure decomposition the original poster is using to introduce secondary air?
I haven’t encountered such a situation where the pre-separation gas phase and the downflow tube get clogged
How do you know it is pre-separation gas-phase overpressure?
Reply to 4# ty0ty00: The pre-separation gas phase is equipped with pressure tapping points
Reply to 3# qiwu9981: It’s possible that…
Reply to 2# lxq700918: Secondary air is introduced from the bottom of the medium-pressure decomposition heater
The pre-separated gas phase goes to the external cooler, while the pre-separated liquid phase goes to the first separation column. The gas phase from this column and dimethyl liquid recover heat in the heat recovery section before entering the external cooler. It is easy to see that the two gases from a certain section converge at the suction external cooler; they both belong to the same section of the system, and their pressures are connected. How can only a pre-separation gas phase overpressure occur?
Reply to 8# ty0ty00: Our company uses a \"pre-separation + pre-distillation\" process; the vapor from pre-distillation goes to a evaporation and heat exchange section, while the vapor from pre-separation merges with dimethyl liquid and is fed into an external cooling unit； The pre-separated liquid phase enters pre-distillation where it comes into countercurrent contact with the vapor from Tower 1