Design guidelines for push-pull ventilation systems through computational fluid dynamics modeling.

Open surface tanks often are used in industrial practice. When harmful substances are involved, control of worker exposure requires the use of a local ventilation system. The push-pull system, among others, involves a jet of air that is blown from one side of the tank and collected by an exhaust hood on the opposite side; this system can save up to 50% of the ventilation air. Several guidelines are available for design of such a ventilation system, mainly based on experimental results. However, their validity is confined inside a narrow operating window. In this work a mathematical model developed based on computational fluid dynamics has been used to extend the validity of the existing guidelines outside the range in which they have been validated, with particular reference to tank width and to the velocity of the air drafts.