Scour Velocity on DIP

[rafklm]

I am designing a Return Activated Sludge (RAS) pipe with cement-lined, ductile iron pipe. Is there a minimum velocity to eliminate the accumulation of solids? Is this infomation published somewhere? ...Thanks.

 

[LHA]

2 fps is a commonly specified and recommended minimum scour velocity for raw sewer water. It is specified for force mains in the PA Domestic WW Facilities Manual on page 34.

Lindbergs CERM on page 28-5 states that 1.5 fps will keep mixed liquor solids in suspension, and 2 fps will allow resuspension of settled MLSS.

Remember: The Chinese ideogram for “crisis” is comprised of the characters for “danger” and “opportunity.”
-Steve

 

[RByra]

You may want to check out DIPRA, Ductile Iron Pipe Institute. They have manuals available with design specifications. Good Luck