Centrifugal Pump for Froth?

[sprintcar]

Centrifugal pumps are'nt the best for moving froth, but we're stuck with the equipment. Any suggestions? There's a debate about high speed vs low speed impellers, large vs small pump sizes, inducers, etc. Basically horizontal, all metal pumps, submerged inlet feeding off the side of the sump, VFD controls, different sizes.

Any practical advice from the experts? - THANKS!

 

[butelja]

In general, centrifugal pumps can't handle much more than 5% gas by volume. Have you looked at side channel pumps? They can handle 50% gas by volume.

Since you go by sprintcar, is this a race engine dry sump application? If so, I thought the scavenging pumps were positive displacement pumps, typically of a spur gear design.

 

[sprintcar]

Actually this is a slurry pump operation. The pumps are in place and the process changed - they want to use existing equipment (naturally) and change the fluid to the froth entrained. Solids are not a problem, but the air really creates pump problems and a need for educating the customer. The inducer didn't seem to help - I think they had more air than they thought and didn't even prime the pump.

The sprint motor is dry sump. I've used both gear and gerotor pumps for engine oil - both seem to work, although the gerotor seems to pull better crankcase vacumn. There's a couple designs w/ air separators, but we just put it back to the tank tangentially and allow for the extra volume. The oil we run (Royal Purple) seems to defroth pretty quickly. I am open to any suggestions!!

 

[stanier]

Warman Pumps (now Weir) have a system for froth pumping used in coal flotation. It really is a piping design solution. A small pipe DN 50 is inserted into the eye of the impeller. The pipe is run vertically above the level in the float cells. The concept is that you actually "burp" the pumps by providing an air release.