Let’s talk about the reasons for PC204 overpressure?

The sudden overpressure of the synthesis tower may be caused by the following reasons:: ⑴Improper operation when reversing the compressor and pump will also cause the pressure to rise. Therefore, when reversing, be sure to pay attention to the amount of material entering the tower and the opening of the pressure regulating valve of the synthesis tower. ⑵Problems with the pressure regulating system will cause the pressure of the synthesis tower to rise linearly: ①Pressure point blocked ； ②The air supply of the regulating valve and pressure transmitter is cut off (air opens the valve) ； ③Regulating valve stuck ； The above reasons will all produce false instructions. If the pressure of the synthesis tower rises, the cause should be found and eliminated in time, and emergency shutdown should be carried out if necessary (when the outlet pressure of the compressor and pump room rises). ⑶The air source pressure of the valve positioner is insufficient, and the pressure input to the diaphragm chamber of the regulating valve is insufficient, causing the valve opening to be insufficient. When the load increases, it is easy to cause overpressure. ⑷After a short period of parking, if the discharge pipe is blocked, the pressure of the synthesis tower will rise linearly, and emergency shutdown must be carried out. ⑸The pressure point is before the check valve of the ammonia inlet tower pipe. Once the ammonia pump trips, the P4 valve in the automatic control state will quickly close. At this time, the A pump and the CO2 compressor are still feeding into the tower, so the pressure in the tower rises rapidly. At this time, the P4 valve should be immediately changed to manual control and maintained at a certain opening to maintain the normal pressure of the synthesis tower.

The reasons for PC204 overpressure are:: 1. Since PC204 is an air-opening regulating valve, if the instrument air pipe is broken, the instrument air will be cut off, which will cause the regulator to close, causing overpressure. 2. A sudden drop in the purity of CO2 and a sharp drop in the urea synthesis conversion rate will also cause overpressure in the urea tower. 3. During the loading process, if the amplitude is too large and PC204 is not opened in time, it will cause overpressure in the urine tower. 4. During the start-up process after a short stop, if the on-site personnel in the pump room and the circulation station do not cooperate properly when adding the third material, the front and rear stop valves of PC204 will not be opened in time after the third material is put into the tower, resulting in overpressure. 5. If the PC204 valve core breaks suddenly, it may also cause overpressure in the urine tower. 6. Due to the crystal blockage of the pressure guiding tube at the PC204 pressure measuring point, PC204 rises. At this time, the display is distorted. You can refer to PI202 and PI203 for judgment.