2 replies to this topic

[davidross]

Hi all,

Can anyone tell me the typical storage conditions for liquid Ethane and Butane for use in a refigeration process and also the downstream equipment (i.e. ambient air vaporisers) and conditions.

Any information would be greatly appreciated!

Thanks in advance

David

[Art Montemayor]

David:

Do you mean to use the Ethane and Butane as refrigerants in a mechanical refrigeration process?

If so, then the Ethane is usually stored at refrigerated temperatures – usually somewhere between 100 psig and 200 psig – depending on the refrigerated temperature selected. At 130 psig, the Ethane has a temperature of -40 ^oF; at 185 psig, the Ethane has a temperature of approx. -6 ^oF. Therefore, you have to select the refrigeration level for the storage of your Ethane. The lower, the storage temperature, the more exotic the vessel metal employed and the more exotic the required insulation.

The Butane you mention I presume to be normal Butane (n-Butane) and it has the following saturated vapor pressures:

60 ^oF : 26 psia
90 ^oF : 44 psia

which are much easier to handle in conventional pressure vessels. A carbon steel vessel designed for 100 to 150 psig working pressure will be sufficient as a storage Butane vessel.

I don’t know what you mean by downstream equipment if you don’t describe your process. A PFD (Process Flow Diagram) will suffice, although a P&ID (Piping & Instrumentation diagram) is even better. When you furnish this basic data we can add further detailed information corresponding to detailed questions on the same.

[ashetty]

Hello David,

Mr.Montemayer,has specified the store conditions of the refrigirants.

By "downstream equipment", I assume you are refering to typical equipment in refrigeration systems.

In a typical single stage refrigeration system the liquid refrigerant is normally stored in a vessel called as the accumulator (sort of a surge drum to ensure the availability of adequate liquid refrigerant for proper functioning of the system).
Refrigerent then flows through a control valve (Expansion valve) for controlling the flow of refrigerant to an evaporator or chiller .This chiller is normally a shell & tube exchanger in which the liquid refrigerant is vaporized by a process stream which is in turn cooled.
The vaporized refrigerened is then routed to a compressor suction KOD and is compresed (screw compressors are common for this application).The superheated refrigerant leaving the compressor is
cooled (The condensor is normally an air cooler) at constant pressure to the dew point temperature,and refrigerant vapors begin to condense at constant temperature and in stored in the accumlator.It is basically a closed loop.

I hope this was what you were looking for.

Regards