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, E-T, was determined as a function of the specific capture flow q(c), m(3)/sm(2), for three tank lengths, L, (1.2, 1.53, and 1.8 m) and several temperatures, T, from ambient to 95degreesC, keeping the surrounding air velocity low (v less than or equal to 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.