Marzal F, Baeza A, Dupero E, Ferrada G, Minna A
Bibliographic info:
in: "Progress in Modern Ventilation", Proceedings of Ventilation 2000, Volume 2, proceedings of the 6th International Symposium on Ventilation for Contaminant Control, held Helsinki, Finland, 4-7 June 2000, Finnish Institute of Occupational Health

The control of emissions from open surface tanks is usually perfomed using simple exhaust systems or combined with push (1). In the first case the exhaust entries generate omnidirectional speed fields within the tank, which rapidly reduce efficiency as the distance increased and are recommended for tanks of less them 1 metre in length. In the push-pull systems, a curtain of air sweeps over the surface of the tank and drags emission towards the exhaust causing a jet wall which (2), when well formed, permits high capture efficiency (3). Random drafts coming from outside distor these push flows to a lesser extent. The description of flow involved in the push-pull system is not simple and even less so whem seeking to explain quantitative aspects, given the high number of variables involved. This paper present the experimental equipment designed for visualising flows and for determining their efficiency as well as the results of the improvement of the geometrical variables for both ventilation system .