RE: [Fwd: queries on compressor]

From: <David>
Date: Wed Nov 16 2005 - 16:29:00 EST

Refer to Skip Foreman's technical paper available at <a href="http://www.dresser-rand.com/e-tech/recip.asp,">http://www.dresser-rand.com/e-tech/recip.asp,</a> particularly the section on unloaders and clearance pockets.

Compressor design usually needs to account for multiple design conditions and this is achieved by designing fixed clearances, optimising valve design, unloaders, pulsation dampners and multi-staging for efficiency when appropriate.

Variable flows are accommodated by using unloaders, bypass lines (wasteful, but cheaper initial outlay), clearance pockets and very occasionally using variable speed motors (expensive).

The power consumption varies with operating conditions and is not constant as you imply.

Regards
David Eastwood

-----Original Message-----
From: <a href="/group/PipingDesign/post?postID=Gviwc8krfq3xEI2o-bpBLmHzlzCwQKlrguQlWd7I7-b8soXqU8BdothX_uRmbEvtVVyc1cX7NOinNt7K6oStiWM_L9kfXY0">PipingDesign@yahoogroups.com</a> [mailto:<a href="/group/PipingDesign/post?postID=Gviwc8krfq3xEI2o-bpBLmHzlzCwQKlrguQlWd7I7-b8soXqU8BdothX_uRmbEvtVVyc1cX7NOinNt7K6oStiWM_L9kfXY0">PipingDesign@yahoogroups.com</a>] On Behalf Of Paul Bowers
Sent: Saturday, November 12, 2005 3:56 PM To: <a href="/group/PipingDesign/post?postID=Gviwc8krfq3xEI2o-bpBLmHzlzCwQKlrguQlWd7I7-b8soXqU8BdothX_uRmbEvtVVyc1cX7NOinNt7K6oStiWM_L9kfXY0">PipingDesign@yahoogroups.com</a> Subject: [PipingDesign] [Fwd: queries on compressor]

Sir,

     I had a question :
      when we operate Reciprocating compressors we are either operating at a

certain fixed motor RPM. This allows for the rated capacity of Compressor.
But if the demand flow rate is required in less quantity i.e. under part-load conditions it doesn't change the RPM accordingly so as to adjust to the desired flow rate. Hence it actually consumes the same power under low-load conditions as the peak-load conditions.

So, can we apply some VFD's for such systems which can adjust accordigly as the desired flow rate so that automatically RPM's vary and power consumed is comparatively less under part-load conditions.

Regards,
Anindya Mazumdar
Maxpro Department
United Phosphorus Limited
Unit-1,GIDC ,Ankleshwar

• Yahoo! Groups Sponsor --------------------~--> Get fast access to your favorite Yahoo! Groups. Make Yahoo! your home page <a href="http://us.click.yahoo.com/dpRU5A/wUILAA/yQLSAA/3GYolB/TM">http://us.click.yahoo.com/dpRU5A/wUILAA/yQLSAA/3GYolB/TM</a>
  --------------------------------------------------------------------~->
  

  ---

PipingOffice - Excel Spreadsheets for Piping Calculations

<a href="http://www.pipingoffice.us/">http://www.pipingoffice.us/</a> =========================================

Main site: <a href="http://www.pipingdesign.com">http://www.pipingdesign.com</a>

Yahoo! Groups Links Received on Wed Nov 16 16:29:00 2005