Development of a Large-Flow-Rate Mist Generator: Prediction of Hydraulic Performance

Sadatomi (2003) invented a micro-bubble generator with a spherical body in a flowing water tube. In the generator, when pressurized water is supplied to the tube, air is automatically sucked through many small holes drilled on the periphery of the tube behind the body, and is broken into a number of micro-bubbles by a high-shear flow of water around the body. In the present study, in order to develop a large-flow-rate mist generator, pressurized air is supplied to the same generator and water is automatically sucked. Experiments were conducted to study the effects of parameters, such as the diameter ratio of the spherical body to the tube, on the hydraulic performance, and the data on the mist flow rate, the pressure at the generator inlet and the distribution of mist diameters were obtained by changing the air supply rate. In the analyses, an analytical model is proposed to predict the mist flow rate and the pressure at the generator inlet at a given air supply rate. In order to validate the model, a comparison is made between calculation and experiment. Results of the experiments and the comparison together with the model are presented in this paper.