Vapor-Liquid Pressure

Hi everyone,

I have a 10m³ liquid receiver filled with 4m³ of ammonia liquid and 6m³ of ammonia gas. The liquid receiver internal pressure and temperatura are: 13,5bar(a) and +35°C. I need to lower the liquid receiver internal pressure in order to transfer ammonia from a truck to the liquid receiver. I have a reciprocating compressor that displace 70m³/h to be connected on the liquid receiver and I would like to know if it is ok to achieve an internal pressure of 2bar(a) in the liquid receiver. I also would like to know how many hours the compressor should run to achieve the 2bar(a).

Does anybody may help me?

Regards,

Volnei

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Originally Posted by Volnei

Hi everyone,

I have a 10m³ liquid receiver filled with 4m³ of ammonia liquid and 6m³ of ammonia gas. The liquid receiver internal pressure and temperatura are: 13,5bar(a) and +35°C. I need to lower the liquid receiver internal pressure in order to transfer ammonia from a truck to the liquid receiver. I have a reciprocating compressor that displace 70m³/h to be connected on the liquid receiver and I would like to know if it is ok to achieve an internal pressure of 2bar(a) in the liquid receiver. I also would like to know how many hours the compressor should run to achieve the 2bar(a).

Does anybody may help me?

Regards,

Volnei

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Volnei, no problem in doing it, but how long not sure.
Once vessel is chilled & forms ice it will stabilize pressure.

I'd guess it would take less than an hour to chill down.

Where is the compressor pumping to, back into the the truck (push/pull method) or back into a refrigeration system?

Volnei why would truck be at 2 bar.
i would have thought it would be at ambient temperature also.

Could you please explain!

Dear RANGER1, thanks for your replay.

The compressor is pumping to an evaporative condenser and the condensated liquid will be drained to another liquid receiver.

We are not lowering the internal truck pressure. It must remain higher as possible to facilitate the liquid transfer to the liquid receiver. We are lowering the internal liquid receiver pressure only.

Regards,

Volnei

Volnei,
The receiver pressure would not necessarily have to be 2bar but anything lower than tanker.
you could vent pressure off liquid receiver back into plant before tanker turns up (if that's the case).

Time of achieving 2 bar will be determined if receiver is isolated. Why not pump the discharge into the truck? You will decrease pressure receiver and increase in truck at the same time. Do it in a controlled way, p.e. VFD on the compressor.