Our
dehydration unit has two (2) 150 cfm Stokes mechanical vacuum
pumps, a 1300 cfm blower and a 600 gallon liquid nitrogen tank.
We perform dehydration by evacuation; to a dew-point of -40 degrees
Celsius - lower if necessary. These units were dried to a dewpoint of -50 degrees
Celsius on the shell and tube side simultaneously.
We have a smaller trailer
mounted vacuum pump and blower for drying smaller exchangers
and/or
systems; usually well below the cost of nitrogen purging.