Small multi-stage reciprocating compressor
Small multi-stage reciprocating compressor
(OP)
I am looking for a list of manufacturers producing small (~200 scfh CO2) multi-stage compressors to boost CO2 pressure from near atmospheric to 1000 psi. Any suggestions appreciated.





RE: Small multi-stage reciprocating compressor
With your flow rate, compressing CO2 this much gives you around 2.5 hp. With interstage cooling losses, I'd probably look at 3.5 hp motor or 5 hp engine.
I've never looked for a 3.5-5 hp 3-stage compressor so I can't tell you where to look.
David
RE: Small multi-stage reciprocating compressor
RE: Small multi-stage reciprocating compressor
A
RE: Small multi-stage reciprocating compressor
RE: Small multi-stage reciprocating compressor
rquery:
What you are looking for is a specialty of Rix Compressors.
Go to: http://www.rixindustries.com/finder.html
Where you can compute the size (Approx. 3 hp) and the specific model they can offer you.
RE: Small multi-stage reciprocating compressor
the rix specified has a 750 psig MAOP, that ain't gonna work unles they give you a waiver.
RE: Small multi-stage reciprocating compressor
dcasto:
The standard for compressing CO2 and liquefying it in the CO2 industry was, for approximately 70 years, a 3-stage compression cycle starting with essentially atmospheric CO2. I designed, installed and operated over 20 of these reciprocating applications in various countries and the usual conditions were, as I remember:
1st Stage Suction = 1 - 1.5 psig, 85 oF
1st Stage Discharge = 60 psig, 250 oF
2nd Stage Suction = 58 psig, 90 oF
2nd Stage Discharge = 260 psig, 275 oF
3rd Stage Suction = 255 psig, 90 oF
3rd Stage Discharge =1,200 psig, 285 oF
I clearly recall that we never came close to the 350 oF. With leaky discharge valves we developed around 325 oF.
Some of the machines were horizontal, in tandem; others were horizontal, balance-opposed. We were the world's largest CO2 producer at the time and we never used a 4-stage recip for this service because a 3-stage did a good job.
I later took some of these compressors and re-bored the 3rd stage oversize to recycle expanded -10 oF vapors generated by expansion of the HP liquid into 250 psig storage tanks. This allowed me to convert what we used to call High Pressure CO2 process to a Low Pressure (250 psig) CO2 process, storing the LP CO2 as saturated liquid and also storing and distributing it as such.
I don't think your concerns about having to use a 4-stage machine are valid.
RE: Small multi-stage reciprocating compressor
RE: Small multi-stage reciprocating compressor
I don't know where the 65F after cooler temP comes from. I don't think I mentioned it and haven't found it in the thread. Have I missed something?
I just wanted to mention the fact that this is not an exceptional or unique application. The Rix compressor recommended by Rix does have a MAWP above 1200 psig - all it is, is a change-out of the 3rd stage cylinder that "sits" on top of the 2nd stage, in tandem. It's a small modification on a small machine and mentioned in their brochure.
Good to visit this forum again, and see the old pros still fighting the good fight with logic, experience, and good sense.
RE: Small multi-stage reciprocating compressor
i was just keeping a design simple. a 65F or even a 30F interstage would be achievable with refrigeration. On a huge scale, that might be cost justified. On a little unit, air cooled interstages is the most economical Adding a stage woulfd be a minimal cos.
I went to the rix site and it recommended a unit. that recommendation was for a 750 psig maop unit. I figuired that they would do a custom machine for not much more to get the 1000 required.