Chem Show '99: Pump Eliminates Need for DAF Air Tanks

Dissolved air flotation (DAF) is an effective way to separate suspended solids and emulsified oils from industrial waste streams, says Larry Shanley, president of Shanley Pump & Equipment, Inc. (Arlington Heights, IL). The small bubbles attach themselves to suspended particles, floating them to the surface for skimming.

Larry Shanley discusses his Edur multistage centrifugal pumps at Chem Show '99.

In the past, engineers aerated their waste streams by injecting them with air from tanks or compressed air cylinders. More recently, organizations have shifted to multiphase centrifugal pumps, which aerate fluids without any external source of air.

A typical DAF system containing an external air supply.

Shanley's recommended DAF system eliminates external air supplies.

At Chem Show '99, Shanley displayed its Edur multiphase centrifugal DAF pump. According to Shanley, the unit produces streams of up to 35% air with 93-100% solubility. The pumps, which achieve flows up to 300 gpm at 400 psi, produce microbubbles as small as 30 micron dia.

According to Shanley, Edur pumps provide steady pumping even when changing points of operation. They are designed for long service life in liquids containing entrained solids (thanks in part to an impeller open on both sides and innovative impeller blades).

For more information: Larry Shanley, President, Shanley Pump & Equipment, Inc., 2525 S. Clearbrook Dr., Arlington Heights, IL 60005. Phone: 847-439-9200. Fax: 847-439-9388.