Recommendations for the design of push-pull ventilation systems for open surface tanks

Abstract

Open surface tanks used in industrial processes often need ventilating to remove harmful pollutants from the working environment. One method which can be used is the so-called side push-pull ventilation system, in which a jet of air is blown (or pushed) from one side of the tank and collected (or pulled) by an exhaust hood on the opposite parallel side. This system is particularly useful for large tanks where access requirements preclude the use of an overhead canopy, and the size of the tank makes side (or rim) exhaust systems prohibitively expensive.Existing design guidelines for push-pull systems vary greatly, although most agree that the system can yield air savings of up to 50%. Starting from an understanding of the nature of the fluid flow this paper develops guidelines for the important parameters of the system and compares these to the recommendations given in earlier work.