2 replies to this topic

[obsidian_dust]

Hi all,

Our unit has operated an Oil-Flooded-Screw-Compressor. That was the first compressor of that kind we had so we do not have much experience about it before. We used it for compressing CDU overhead gas - which is designed to contain about 4% - 8% vol of C6+ and 9-16% vol of mixed C5. But the actual number is higher. The C6+ can be about 18% and mixed C5 can be about 20% vol.

Since the compressor was operational, we see that the lube oil is frequently contaminated with liquid hydrocarbon. Firstly we think that there ia a separation problem took place in compressor's KO drum. But after we re-evaluate the sizing of the KO Drum (including the mesh pad), we realize that the sizing was correct so we think that the problem most probably caused by liquid droplet carry over whose size is too small to be separated by gravity settling and pass through the mesh pad (perhaps the droplet size was smaller than 10 micron). Unfortunately, the nature of the compressor itself looks less tolerable to the existence of the liquid entrainment.

The effort to reduce heavy hydrocarbon entrained from CDU overhead receiver has been continuously made, but the problem is still occurs. So we tried to look for another option which is involve the upgrading of the compressor's protection. Is there anybody has the same kind of experience so can suggest us what kind of equipment (it can be an additional equipment in the KO drum internal or an additional dedicated equipment in the upstream compressor) will be most effective to minimize those kind of problem?

Thank you very much and best regards.

[JoeWong]

obsidian_dust,

Can you advise if your compressor cooling is done by lube oil or you have dedicated cooler for process gas ?

What the compressor suction and discharge operating pressure and temperature ?

What other heavy component for C6+ ?


May able to help if you can furnish above information.



JoeWong

[obsidian_dust]

Can you advise if your compressor cooling is done by lube oil or you have dedicated cooler for process gas ?

The compressor cooling is done by the lube oil (the lube oil system is equipped with an air fan cooler)

What the compressor suction and discharge operating pressure and temperature ?

The suction temperature and pressure should be 60 deg C and 0.5-0.8 kgf/cm2 g; the discharge operating temperature and pressure should be about 86 deg C (and then would be cooled to 49 deg C in a fin fan cooler before transferred to downstream unit) and 1.9 kgf/cm2 g

What other heavy component for C6+ ?

Unfortunately, we haven't made any breakdown analysis yet. The C6+ content came from GC (whose limited until C6+), but once we measured the specific gravity, it was about 0.6778


May able to help if you can furnish above information.

Thank you very much. I really appreciate that.



JoeWong
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