lpg & other issues

[Lekoso]

Hi everybody,

I have just been assigned to this lpg transfer (from cargo to bullets, then to loading trucks) project and I must confess I am a newbie in this area,so I must ask these questions, even if they are so fundamental.

What dictates the choice of the driving medium, a pump or a compressor? From what I gather, lpg (mixture of propane & butane)is liquid at moderate pressure and high vapour prressure, so I would think the choice of a compressor for transference would not be an options since compressors disagree with liquids.

Also, how is it possible to fill an an empty-air-filled vessel, with lpg? Do vessels (either the bullets & the truck cargo) need to be under some sort of vaccuum to evacuate the air before filling with lpg?

Finally, can I be directed to any literature or book apart from API 2510, that might assist me in my project?

Thanks

Regards

 

[BigInch]

LPGs have relatively high vapor pressures and gas bubbles are often found in suction lines, so typically a vane pump is used for liquid phase transfer. Vane pumps are capable of handling more gas in a liquid stream. See Corken Pumps

http://www.corken.com

Its usually sufficient to purge lines and tanks that are initially filled with air with an LPG gas stream until all air is pushed out ahead of the LPG. If the purge is done fast enough, very little air will mix at the interface, so a pure LPG stream will remain behind. The design of the piping system should avoid dead legs, so to minimize areas that can trap air when an interface passes. If dead legs cannot be avoided in some situations, they should have a purge valve located at their ends.

Corken's training manuals may be of some interest to you.

http://www.corken.com/publications/training.html

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"Pumping accounts for 20% of the world’s energy used by electric motors and 25-50% of the total electrical energy usage in certain industrial facilities."-DOE statistic (Note: Make that 99% for pipeline companies)

http://virtualpipeline.spaces.live.com/

 

[CH5OH]

normally a tank would be either have nitrogen in it or LPG in vapour phase

 

[dcasto]

i'd use a compressor to transfet the LPG from the barge to the bullets because you can also remove the vapors from the barge. The Corken link shows this.

Then use pumps to load the trucks.