Experimental investigation of producing ice slurry with water using opposed-nozzle impinging jet method

Abstract

In order to improve the efficiency of producing ice slurry, an experimental device of opposed-nozzle impinging jet was established. Deionized water of 2.5–10.5 °C was jet impinged with chilled air in an ice-making tank. The spray and performance of impinging and non-impinging jet was evaluated. The results show the temperature around the water nozzle is higher, which is benefit for preventing ice blockage. The impinging jet makes the water droplets smaller, more evenly distributed and longer residence time, which strengthens the turbulence flow and heat transfer, as well as reduces supercooling degree of water, while increasing the production of ice particles. The ice packing factor (IPF) decreases with the rise of the water initial temperature, but the corresponding reduction rate is smaller at the higher initial temperature. Meanwhile, the maximum IPF and the utilization rate of cooling capacity of impinging jet are about 4 times than that of the traditional non-impinging jet as the initial water temperature is in the range of 2.5–10.5 °C. The refrigeration coefficient of the ice-making system increases with the initial water temperature. The impinging flow can greatly improve the refrigeration coefficient of the ice-making system. The average refrigeration coefficient of impinging flow system is about 1.6 times that of non-impinging flow system in the range of 2.5–10.5 °C of the initial water temperature. Moreover, the impinging flow improves the refrigeration coefficient of the system more significantly under the condition of lower initial water temperatures.