Compressed air surge tank for dense phase conveying service

[Chiu22]

Dear all,

I am trying to calculate an ideal capacity of air surge tank for keeping stable supply air source. But I need to provide 2 of difference air pressure source for 2 dense phase transfer system. Details are as below.

1.The first dense phase system need a constant air supply system, air source was set at 2.8 barg, if the pressure over the 2.8 barg we had a relief valve to control it.(total air consumption is around 4300~5700Nm3/hr).

2.The second dense phase system could be operated in a variable of compressed air supply source, it depends on the load/unload range of compressor, we usually set 3.0 ~ 3.55 bar (total air consumption is around 5200~6800Nm3/hr).

I have an idea that constructing an air surge tank and also to install a PIC device to meet our requirement. But it is very hard to determine the optimun volume for air surge tank, I would to know what basic principles could be followed or any good ideas can offer from you.

Chiu22.

 

[quark]

That depends upon the compressor capacity and your load pattern. Conceptually, compressor directly feeds the continuous requirement and receiver feeds the intermittent requirement. The link below gives you good leads.

http://www.pyebarker.com/TechTips/techtip3.htm

 

[reena1957]

Dear Chiu22,
Normally the surge vessel is sized to provide an emergency cushion in case the compressor trips, so as to have a smooth shutdown of the consuming system, especially for instrument air. Also it is used in case consumption is highly irregular so that there is always a source avaialble to supply. However, in your case, it is not the case. So Simply provide a Back Pressure control valve leading to the consatnt pressure consumer so that it will not normally let the relief valve pop to let the air vent into the atmosphere. However, leave the Relief valve in place to take care of unforeseen situations like stuck-up back pressure control valve.
Best wishes