RE: 2-phase Flow versus Velocity [bcc][faked-from][mx][spf]

From: <Bruce>
Date: Thu Sep 08 2005 - 16:06:00 EDT

What is the purpose of aerating the water? Must it be foaming? Since you work for Nalco, I gather that you are intentionally adding a surfactant to make it foam. Can less (or more) of the surfactant be used, reducing foaming potential? If if must foam, or foam is desireable, must a centrifugal pump be used? Can you consider an eductor (jet pump) or other type of mover? 8-10 fps is in the range of a properly sized line, so why would that be a new approach (have you typically run at 4-5 fps or lower, which is often less economical for pipe sizing, but might save a little on the pump capital cost since there is less head loss)?

                            ... Bruce D. Bullough ...
                            Sebesta Blomberg & Associates, Inc.
                            2381 Rosegate
                            Roseville, MN  55113          USA
                            desk: 651-634-7344   fax: 651-634-7400
                            www.sebesta.com

-----Original Message-----
From: <a href="/group/PipingDesign/post?postID=J5LqSZDF8HIjMs-2a21UQNUOuPqw0yOK-ULIRgrdXO0-JoEBiAT7l8YSb6NtmzYswzIuHXV74qF1HKdXH5m-GdtF">PipingDesign@yahoogroups.com</a> [mailto:<a href="/group/PipingDesign/post?postID=J5LqSZDF8HIjMs-2a21UQNUOuPqw0yOK-ULIRgrdXO0-JoEBiAT7l8YSb6NtmzYswzIuHXV74qF1HKdXH5m-GdtF">PipingDesign@yahoogroups.com</a>] On Behalf Of Thomas Laupa
Sent: Thursday, September 08, 2005 9:02 AM To: <a href="/group/PipingDesign/post?postID=J5LqSZDF8HIjMs-2a21UQNUOuPqw0yOK-ULIRgrdXO0-JoEBiAT7l8YSb6NtmzYswzIuHXV74qF1HKdXH5m-GdtF">PipingDesign@yahoogroups.com</a> Subject: [PipingDesign] 2-phase Flow versus Velocity [bcc][faked-from][mx][spf]

>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

---

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 Thu Sep 08 16:06:00 2005