Suction Header Clarifier

DESCRIPTION:
 
One or two round or square tapered headers stretch from a manifold radially across the bottom of the clarifier.  Varying size and spaced orifices located in the leading edge of the suction header are designed to draw settled sludge at an even removal rate across the entire basin floor.  Through pumping, or head differential, settled solids are drawn through the header into the manifold and out of the clarifier.  

ADVANTAGES:

1.    Rapid removal of solids across the whole clarifier floor.

DISADVANTAGES:

1.    Potential plugging of the suction header holes at low RAS removal rates.
2.    If the actual RAS flow rate is different than designed for, the header may draw solids at an uneven rate across the basin floor.
3.    Because the header draws equal to the area it rotates through, a sludge blanket must be maintained over the entire clarifier deeper than the suction header.
4.    A seal must be maintained between the rotating manifold, the clarifier center column, and the tank floor.  High head differentials for the suction header may cause the seals to collapse or “suck in” rendering them useless.  
5.    The seas must be replaced approximately every 5 – 7 years.

VARIATIONS:

1.    Install a segmented rake as one arm opposite the suction header to aid in redistribution of the sludge on the bottom.