air compressor intercooler design 1

[shipvibration]

it is common to put fluids with low heat transfer coefficient on the shell side of heat exchangers.
but in many air compressors the air is placed inside the tubes.what is the design factor consideration ?
thanx.

 

[TBP]

An important consideration is the pressure drop across each side of the HX. The determining factor regarding which fluid is in the shell, and which is in the tubes is often which has the higher flow. Another consideration is operating pressures. If there are high pressures for one fluid involved, this usually means it will go in the tubes, as the larger the diameter, the heavier the wall needs to be. Putting a very high pressure fluid in the shell (considerably larger diameter as compared to a tube) will mean a very heavy, and expensive, wall.

 

Most of the air compressor intercoolers that are in service in air separation plants (2000 hp thru 25000 hp) have the air on the shell side. It permits a good method of separation of the condensed water vapor from the air. Nitrogen compressors have nitrogen on the shell side up to several hundred psi.