effluent launder is manually adjusted by leveling rods (18, fig. 1-3) to permit leveling and skimming of the water surface.
The clear water is discharged across the slurry pool to the wet well tank (7) through the effluent launder discharge tube
(5, fig. 2-27).
Wet well tank.
The wet well tank provides limited storage of coagulated water and serves as a sump for the filter
An overflow pipe in the wet well tank permits operation of the erdlator at rated capacity when the filter
is stopped. A switch, operated by a float in the wet well, activates an alarm bell and a red signal light when float valve is
The float valve FV-18 (10, fig. 2-13) is actuated through a lever connected to float located in the wet
well tank. This float valve, located in the raw water bypass, allows additional raw water to enter the system whenever the
amount of water in the wet well falls below a preset level.
A drain in bottom of the wet well tank permits complete drainage of the tank to waste when water
unsuited for filtering is obtained from the erdlator tank.
Sludge concentrator tank.
The flocculent slurry flows by gravity from the erdlator tank to the sludge concentrator tank.
The sludge concentrator tank functions as a small auxiliary clarifier. It provides a longer holding period
for slurry concentration and reduces the water rise rate for separation of clear water from the slurry.
The sludge concentrator tank permits settling of slurry in the bottom of the tank for continuous or
intermittent drainage to waste. It also permits the skimming of clear coagulated water at the top of the tank for return to
the wet well from where it is pumped to the filter.
The draining of slurry to waste and the return flow to the wet well is manually controlled, depending
upon the amount of slurry produced in the erdlator tank.
Chemical solution feeder. The chemical solution feeder (4, fig. 2-10) pumps ferric chloride and calcium
hypochlorite solutions into the downcomer or mixing zone (4, fig. 2-27). The pump discharge rate is adjustable but
delivers a fixed constant rate of feed with each pump stroke at any one setting.
Chemical slurry feeder (limestone compartment).
The chemical slurry feeder tank (1, fig. 2-10) supplies pulverized limestone (coagulated aid) to the
mixing zone of the erdlator tank.