Studies on Ultrasonic Spray Dryer (1)

Author has initiated research and development activities for a epochal ultrasonic spray dryer in order to obtain large quantities of droplets in uniform diameters, from which a practically applicable ultrasonic spray dryer would possibly be developed. Since the time Wood, Loomis et al. reported their experiments on atomization of liquids by ultrasonic power, research in this field is now widely attempted in many countries. In Japan, this field is being investigated by Ohno et al. Chiba, and Mizutani et al. Experiments so far carried out, however, have been limited in scale and capacity, with liquid volumes maximum 25 liters per hour and for application purposes only for oil burners or medical-use atomizers, etc. This report deals mainly with (1) test manufacturing of an ultrasonic elastic oscillatory atomizer having a wide spray area to produce a thin enough liquid film to atomize a large supply of liquid, (2) test production of an ultrasonic power accumulator capable of accumulation and supply of sufficient ultrasonic power for atomization of a large quantity of liquid, (3) test production of three types of ultrasonic atomizers having resonant frequencies of 20kHz, 28kHz, and 50kHz respectively, and confirmation of atomizing dependence upon the ultrasonic frequency, and (4) atomization tests with liquid supplies maximum 200 liters per hour.Author has initiated research and development activities for a epochal ultrasonic spray dryer in order to obtain large quantities of droplets in uniform diameters, from which a practically applicable ultrasonic spray dryer would possibly be developed. Since the time Wood, Loomis et al. reported their experiments on atomization of liquids by ultrasonic power, research in this field is now widely attempted in many countries. In Japan, this field is being investigated by Ohno et al. Chiba, and Mizutani et al. Experiments so far carried out, however, have been limited in scale and capacity, with liquid volumes maximum 25 liters per hour and for application purposes only for oil burners or medical-use atomizers, etc. This report deals mainly with (1) test manufacturing of an ultrasonic elastic oscillatory atomizer having a wide spray area to produce a thin enough liquid film to atomize a large supply of liquid, (2) test production of an ultrasonic power accumulator capable of accumulation and supply of sufficient ultrasonic power for atomization of a large quantity of liquid, (3) test production of three types of ultrasonic atomizers having resonant frequencies of 20kHz, 28kHz, and 50kHz respectively, and confirmation of atomizing dependence upon the ultrasonic frequency, and (4) atomization tests with liquid supplies maximum 200 liters per hour