Effect of Drift Eliminator Design on Cooling Tower Performance

Abstract

In the use of wet cooling towers, drift refers to small droplets of circulating water that are carried out of the cooling tower by the saturated exhaust air. Inertial impaction separators, known as drift eliminators, are used to strip the water droplets from the exhaust air. To achieve peak cooling tower operating efficiency, it is desirable that losses in fan system performance due to the drift eliminators be minimized. Therefore, an experimental program was developed and executed to evaluate the effect of drift eliminator design on cooling tower fan system performance. Flow visualization studies were used to gain insight into the flow patterns within the cooling tower plenum as influenced by drift eliminator design. A fully instrumented fan test cell was used to investigate the effects upon fan system performance resulting from two different styles of drift eliminators. The effect of drift eliminator discharge angle upon fan system total efficiency was investigated and the optimal discharge angle determined.