Ice slurry production via opposed-jets spray: An experimental and theoretical study

• Increased air–liquid nozzle angle resulted in 6.09 % increase in Ice packing fraction. • Cold energy utilization rate increases by 16.02% when nozzle angle increased. • The optimal for nozzle distance, air and liquid flow rate are 8 cm, 6.4 m 3 /h, and 48L/h. • A novel mathematical model is built up with high correlation. The opposed nozzle impinging method is a novel developed technology for ice slurry preparation, which has more advantages than the traditional method, such as increasing the effective heat transfer contact area, significantly reducing ice plugging, and improving the heat transfer efficiency. The injection angle, flow rate and injector distance are investigated experimentally in this work due to their great influence on system performance. Consequently, the optimum parameters and the functional relationship between the system performance parameters and the key operating parameters are obtained. It is shown that increasing the spray angle of the gas and liquid streams increases the ice packing fraction (IPF) by up to 6.09 %. The increase in the IPF growth rate is 2.974 times greater when the gas spray angle is changed from 45° to 105°, compared to a similar change in the liquid nozzle angle. The cold energy utilization rate of the ice slurry generated increases by 16.02 % when the gas–liquid spray angle increases from 45° to 105°. Moreover, the order of influencing factors on the IPF and heat transfer efficiency according to orthogonal experiments from the highest to lowest is distance between nozzles, liquid nozzle flow rate, air nozzle flow rate. The optimal values for the nozzle distance, air nozzle flow rate and liquid nozzle flow rate are 8 cm, 6.4 m 3 /h, and 48L/h, respectively. Moreover, a novel mathematical model is built up to explain theoretically the influence of spray angles, fluid properties and construction parameters on ice content.