What are the reasons that can cause downstream equipment to shut down during tank cutting?
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What are the reasons that can cause downstream equipment to shut down during tank cutting?
A few days ago, when we switched the propylene feed tank, cavitation in the propylene transfer pump caused an emergency shutdown of the polypropylene production unit. The pressure in the tank that was switched to was 1.28 Mpa with a high liquid level, while the pressure in the original feed tank was 1.40 Mpa with a low liquid level. Could these conditions have affected the switching process?
Simply view the interlock setting table for the downstream units, and identify the factors related to the tank switching process to understand it.
I also think it’s necessary for the device to figure out why it stopped, before it can be analyzed
Possible reasons: 1. Low pressure in the tank being pumped, resulting in low suction pressure by the pump and causing vacuum formation. 2. During the tank cutting process, the valve on the pipeline leading from the feed tank to the pump is not closed in time, which results in material being forced from the tank with a high liquid level into the tank with a low liquid level. If the direction of this material flow is opposite to the direction of pumping, it will lead to insufficient pumping flow and low suction pressure, thereby causing vacuum conditions.