Analytical Model for Evaluating Lateral Capture Efficiencies in Surface Treatment Tanks

A pilot scale installation 1.8 m long and 1.6 m wide was designed to simulate a surface treatment tank incorporating a lateral capture system and a distribution network that permits the surface emission of tracer (SF6). The capture efficiency, ET, was determined as a function of the specific capture flow qc, m3/sm2, for three tank lengths, L, (1.2, 1.53, and 1.8 m) and several temperatures, T, from ambient to 95°C, keeping the surrounding air velocity low (v≤0.1 m/sec). The data showed a satisfactory fit to a model that related capture efficiency with two exponential functions: the first dependent on the ratio capture velocity/air velocity in the vicinity of the tank, and the second on the ratio capture velocity/velocity of rising drafts provoked by the temperature of the tank.