Pump Question
Pump Question
(OP)
I'm trying to size a pump for a heating and cooling application for a chemical process. They need about 80 gpm with 275-300 ft of head using 55% ethylene glycol. The temperature range is 0 degrees F to 135 degrees F. I've been looking a centrifugal pumps but keep ending up at the top of the pump curve. Would a gear pump be a better use? Or will I run into problems with the gear pump because of the temperature swings and thermal expansion of the gears? Is there a "rule of thumb" that says if above a certain head pressure a gear pump is better application?
Thanks
Thanks
RE: Pump Question
80 gpm @ 300 feet of head is absolutely not a problem for centrifugal pumps.
Unless there is something you are not telling us, piston pumps would never be considered for that application.
Solution - You are not looking at the right pumps or right manufacturer.
That basic requirement of 80 gpm @ 300 feet is doable with 10,000 different pumps by 500 different manufacturers to start off, some will be eliminated by other criteria such as NPSHr, Ns, Nss, Efficiency, curve geometry, range, etc.
PUMPDESIGNER
RE: Pump Question
I have spoken with Viking and they think a lobe pump would be the best application because of the thiness of ethlyene glycol at 135 degrees F. I said that I might be able to change some of the arrangement and change the pressure drop to 200 feet of head. They thought a gear pump might work. I don't have much experience with lobe pumps. What do you think?
RE: Pump Question
http://www.haightpump.com/
RE: Pump Question
If you are trying to run with no control on the system,then you will get fluctuation, but if you want no fluctuation you will have some sort of control system.
I cannot see anything in what you are saying that prevents the use of a centrifugal pump.
RE: Pump Question
RE: Pump Question
0oF is a cryogenic condition that may require pre-cooling of the pump. Anyway, materials of construction should be selected accordingly.
As for myself, I don't see why a centrifugal couldn't meet the requested operating conditions with suitable flow control devices.
EG is considered somewhat toxic and should be handled with care.