Dear Good Group:
Thanks to all who responded and additionally to those who let me pester them
with more questions. Iım going to be continuing to work on our air system
proposal, so anyone who wants more nitty-gritty details when we get to the
decision phase, please just email me.
Margaret
Summary (8 responses):
Oil-Free Compressors:
No one responded that they had any experience with oil-free rotary screw
compressors.
Scroll compressors that have been used successfully are: Atlas Copco
(including model SF4), Anest Ewata, and Powerex. One respondent had a very
bad experience with a Powerex scroll compressor that overheated and shut off
at low duty cycle, making it unable to produce the needed CFM. However, one
site currently has a Powerex that is working well, with an exhaust system
that removes excess heat from the room.
Oiled Compressors:
Two respondents advocated for oiled compressors, since oil-free air can be
obtained from an oiled compressor by making sure that any oil that escapes
from the compressor is filtered from the air stream. Kaeser compressors,
including the Kaeser oiled rotary screw, are recommended. Some advantages
of oiled compressors are that they are commonly available, less expensive,
generally considered routine to maintain, and long lasting.
Werther International, which supplies both oiled and oil-free compressors,
was also recommended by one respondent.
Some good general advice for making a new air system:
1. Identify who is going to maintain the system, and involve them in the
selection process, since they may have preferences about compressors.
2. Buy local, so that parts and warranty service are readily available.
3. Oversize the compressor, so that future expansion and unfortunate
leakage do not cause supply problems.
4. Have large receiver tank volume.
Original question:
Please let me know of any positive or negative experiences you have with
oil-free rotary screw compressors or oil-free scroll compressors, and if you
are running a system with one of these types of compressor to supply air for
NMR spectrometers, which model and manufacturer you are using. We are
needing to increase output of our air system to supply more spectrometers,
and we seem to have outgrown oil-free reciprocating compressors, which in
any case are less available now that Quincy has stopped making them. I
would appreciate any comments on good working systems designed to supply 6
or more spectrometers including a lot of solids (MAS). Thanks.
Received on Wed Aug 26 2015 - 09:03:48 MST