There is always liquid at the inlet of the propylene compressor; the propylene pump has to be started from time to time due to this issue
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Dear sea friends: Does anyone know anything about the issue of liquid continuously present at the inlet of propylene compressors? Since starting operation with the drive, there has been liquid at the inlet of the propylene compressor; the anti-surge valve has remained open, and the liquid level in the propylene cryocooler for low-pressure methane is also very low. Nevertheless, there is still liquid in the liquid separation tank at the first-stage inlet of the compressor. Operators need to start the propylene pump regularly. Has anyone encountered this situation? How to avoid liquid at the inlet?
What is the pressure in your tank?
It is recommended that you use an on-site level gauge to drain the liquid from the compressor inlet separator tank, to see if liquid can be discharged. If liquid does come out, conduct further analysis to determine its composition.
I’m asking, has this problem been resolved? We have encountered this situation recently as well
This is likely due to the anti-surge valve being fully open, which results in a higher temperature in the inlet separation tank. To balance the temperature, propylene from the intermediate storage tank flows into the inlet separation tank through the control valve. You might try reducing the opening degree of the anti-surge valve to 60%, and keep an eye on whether surge occurs; if that doesn’t work, try setting it to 100%
Hello, has this issue been resolved? Could you tell me what the reason is? For this new project we’re working on, let’s see if it’s possible to avoid that when driving
It must be caused by an excessive opening degree of the anti-surge valve!
1. Check whether the liquid level setting for the propylene heat exchanger is too high 2. Check whether there is liquid accumulation at the lowest point of the gas pipeline
Actions can be taken from the following aspects: 1. Check the liquid level in the propylene cooler of the low-temperature methanol wash unit to ensure that it is below 45%. 2. Control the inlet temperature of the first stage of the compressor at around -28°C using an anti-surge valve and a temperature control valve, while keeping the inlet pressure at 30–35 KPa. 3. Verify that the local level gauge at the inlet displays accurately. 4. Check whether there are low points in the gaseous propylene pipeline that could cause condensation to accumulate. 5. The propylene pump located at the bottom of the inlet separator is in cold standby mode; meanwhile, the high-level interlock system is activated for automatic startup. 6. Analyze the composition of the gaseous propylene to prevent the accumulation of impurities; if such accumulation occurs, condensation can be removed from the top of the condenser or from the low point in the inlet pipe of the subcooler
The main reason for this is that the opening degree of the propylene liquid-phase valve in the non-condensable gas separator is too large. During normal operation, when there is no need for venting, this valve can be closed completely; it has nothing to do with the opening degree of the anti-surge valve. It depends on the temperature at the outlet of the water cooler being higher than the saturation temperature corresponding to the current compressor outlet pressure
Is the valve for admitting liquid not sealing properly?