Issue regarding the discharge destination of liquids from the liquid separation tanks at various inlet stages of the new hydrogenation cracking unit
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Our new hydrogen compressor features four stages of compression; the pressure after these four stages is 19.7 Mpa. Please tell me whether the liquid from the inlet strainers at each stage should be discharged into the low-pressure vent tank or the high-pressure vent tank.
The safe approach is to discharge it directly into the low-pressure separation tank (I think what is meant is the flare line).
Ours features double three-stage compression, with all stages connected to low-voltage lines. First, there is virtually no risk of liquid presence; second, when draining the liquid, the valve is opened slightly and drained frequently – short-term drainage prevents high pressure from leaking into the low-voltage system. Please feel free to point out any mistakes!
Double three-stage compression is used in hydrorefining, right? A pressure of around 9 MPa is sufficient; we use four-stage compression
Previously, the liquid separation tank between stages of the new hydrogen compressor in the facility was connected to the on-site drain, while the tank at the inlet of the recycle hydrogen compressor was connected to the cold liquid separator, using angle valves for this purpose
We use three-stage compression, with the liquid from each stage being sent to the flare line
We discharge it into underground oil waste pipes; it’s a normal-pressure operation. The vent valve on top of the tank remains open at all times. During regular liquid removal, the vent valve is closed and the valve leading to the flare line is opened. Then, the nitrogen valve is opened to use nitrogen to push the condensed liquid into the flare tank. It’s probably this process.
We go to the liquid vent line and then to the vent tank