RE: Required pipeline water velocity to flush air from line

AFT will do this

al

From: <a href="/group/PipingDesign/post?postID=g1FSNu5JXg7i8QzxcgNgsv1k5YR-RAodOoKZGdcFTbV7CiB3mQLWpEKnEef15f-pmdGg9NiEl6VTdsb60plc1NnQd5Tx1F8">PipingDesign@yahoogroups.com</a> [mailto:<a href="/group/PipingDesign/post?postID=g1FSNu5JXg7i8QzxcgNgsv1k5YR-RAodOoKZGdcFTbV7CiB3mQLWpEKnEef15f-pmdGg9NiEl6VTdsb60plc1NnQd5Tx1F8">PipingDesign@yahoogroups.com</a>] On Behalf Of Steve McKenzie
Sent: February 22, 2008 1:54 PM
To: <a href="/group/PipingDesign/post?postID=g1FSNu5JXg7i8QzxcgNgsv1k5YR-RAodOoKZGdcFTbV7CiB3mQLWpEKnEef15f-pmdGg9NiEl6VTdsb60plc1NnQd5Tx1F8">PipingDesign@yahoogroups.com</a> Subject: [PipingDesign] Required pipeline water velocity to flush air from line

Gents
With a water pipeline containing air, it is common practice to install air eliminators at the high points. However it should be possible to use the water to sweep the air along with it if the water velocity is sufficiently high. I could have a shot at calculating the velocity, but the assumptions would have to be on the simplistic side. The essential problem is to find the water velocity in a pipe of given downwards inclination, where the buoyancy force of the air bubbles equals the downwards drag force of the water on the air. The major independent variables would appear to be; pipe diameter, roughness, inclination, effective water depth in the pipe, air viscosity and density/pressure. Any help of referrals would be appreciated.

Cheers

Steve Mckenzie

[Non-text portions of this message have been removed] Received on Fri Feb 22 19:00:00 2008