MODELING OF ATOMIZATION RATE DURING GAS ATOMIZATION

A mathematical model provides the tools to compute the atomization rat e from the backpressure, and the height of the descending liquid head and the amount of the over-pressure required as the functions of the a tomization time. The computed data agree reasonably well with the expe rimental data. The roughness of the inner wall of the liquid delivery nozzle becomes influential on the atomization rate at larger liquid fl ow rates. Three regimes were observed sequentially during the course o f manipulating the backpressure. In the Normal Atomization Regime, the atomization rates are only slightly larger than the free water flow r ate. In the Backpressure Regime, the atomization rate starts to decrea se dramatically. In the Backsplash Regime, the atomization rate starts to increase, and the water was atomized and backsplashed concurrently . As the atomization gas pressure increases, the atomization rate in t he Normal Atomization Regime increases, the atomization rate in the Ba ckpressure Regime decreases, and the relative position of the exit of the liquid delivery nozzle where the Backsplash Regime begins to move upwards. As the water head decreases, and the included angle and the a tomization gas pressure increase, the effects of the backpressure on t he atomization rate increase. (C) 1998 Acta Metallurgica Inc.