Page 27 - Simplified Wastewater Treatment Fundementals\Pumps and Pumping

Pumps and their Applications

Other types of positive displacement pumps include:

Rotary Lobe Pumps are positive displacement pumps typically designed to pump sludge with high

discharge head demands.

Peristaltic Metering Pump utilizes a tube that is pinched and relaxed by rotating rollers to

accurately deliver small volume liquids, including chemicals.

The wearable part for this pump is the flexible tube, which must be replaced at least annually.

Diaphragm Pumps operate by opposing, alternating diaphragms, designed to pump a wide range

of low to medium volume solids against high head demands. Diaphragm pumps are powered by

compressed air. When air pressure is increased, the diaphragms fill and push sludge faster.

Operating diaphragm pumps at too high of a rate can result in air line freezing, even during

summer months. Diaphragm pumps make a popping sound with the evacuation of sludge from a

diaphragm. The informed Operator will listen and know the pump popping frequency to ensure

the pump is operating correctly. A struggling pump, due to poor air supply, a leaking air line, or a

clog will begin to make a fluttering sound, or will not pump (or pop) at all.