Hi Charlie,
Here there are four separate installations where we use a Kaeser Sigma
screw compressor followed by a large receiver tank. The receiver output
then goes through a moisture separator filter, oil removal filter,
recycling dessicant dryer, particle filter,and oil vapor absorber, in that
order and all from Kaeser. This supplies 100psi to each instrument site.
Total cost for this end of the system is $6,000 to $10,000 depending on how
much flow is needed. For just one liquids-only installation, you could
probably get that price down more. The Kaeser compressors are pretty
dependable once you get the pulleys aligned so they don't chew belts.
At each instrument there is a particle filter, pressure regulator, moisture
separator, and charcoal filter, not necessarily in that order. These are
small low pressure units, and the instruments get 30 - 40 psi, depending on
the demand of the individual system. On this end, each installation runs a
few hundred dollars.
To avoid pressure drops at higher flows, be sure that the piping from the
compressor site to the instrument site is large enough. Proper sizing
depends on type of pipe, length of run, and number of fittings. In the
absence of a good M.E. to figure the proper size, bigger is better! One
inch pipe or tubing is normally plenty for almost any application. I
recommend copper tubing, due to iron filings possible from regular pipe.
Even after all of this conditioning, we still switch to LN2 boiloff for
low-temperature V.T. work!
Happy spinning,
Jerry
===+++===
Jerry Hirschinger, NMR Instrumentation Engineer
Purdue University Interdepartmental NMR Facility
1393 Wetherill Labs, rm. 365A
West Lafayette, IN 47907-1393
Phone: (765) 494-5288
FAX: (765) 494-0239
email: hirsch@purdue.edu