2-phase Flow versus Velocity

>Ladies and Gents:

would appreciate your input on a system design... we have a 5000 gallon tank which we use as a sparging vessel. it generates a highly aerated water solution which we need to pump out of the vessel.

when the solution comes out of the tank it is a foam. we've found it difficult to pump. on our existing systems we are using a centrifugal pump running at low speed. we also have elevated the sparging vessel to produce as much elevation head on the pump as possible.

on our new systems the question is how to size the pump suction piping. one school of thought is to keep it as large as possible to minimize suction losses. the second school of thought is to keep velocities in the range of 8-10 ft/sec to keep the foam "areated" and prevent it from forming big bubbles.

what would you suggest?

>

Thomas G Laupa PE
Senior Engineer - Nalco Company
Office Address: 1601 Diehl Road, Naperville, IL, 60563 Courier Address: 1003 Remington, Fort Collins, CO, 80524 970-227-5127
800-493-5009 fax Received on Thu Sep 08 10:01:00 2005