Study on ice slurry production by water spray

A theoretical and experimental study was performed to examine the water spray method of ice slurry production. First, the conditions for the formation of ice particles were investigated theoretically by the diffusion-controlled evaporation model. The prediction of the model was proved to agree relatively well with experiments in which we examined the conditions for a droplet of initial temperature 20°C and size 50 μm to change into an ice particle in a chamber of height 1.33 m. Second, the production of cold storage heat will increase almost proportionally to the number of spray nozzles because no substantial difference was found in the Sauter Mean Diameter (SMD) of sprays from single and twin nozzle. Third, an ice slurry was experimentally obtained by spraying droplets of 7% ethylene glycol aqueous solution in a vacuum chamber where pressure is maintained below the freezing point of the solution. Finally, based on the theoretical and experimental results, we propose an optimizing chart for providing the operating conditions to make ice slurry using the relations of the staying time of the droplet in the chamber, the injection pressure, the spray droplet size and the chamber pressure.