PARAMETRIC STUDY ON THE BULK HYDRAIRCOOLING OF SPHERICAL FOOD-PRODUCTS

A numerical study of the bulk hydraircooling of spherical food product s is performed using the technique of spraying chilled water to form a thin film over the food products while blowing cold unsaturated air i n the countercurrent or cocurrent direction. This precooling process i s found to combine the advantages of hydro- and air cooling. Governing equations describing the simultaneous heat and mass transfer occurrin g in the hydraircooling process for both counterflow and parallel-flow arrangements are solved using finite-difference numerical methods. A parametric study is performed to determine the effect of important pro cessing parameters on the process time. It is generally observed that higher quantities of spray water, air-mass flow rate and product therm al conductivity, as well as lower values of water temperature will res ult in faster rates of cooling. For the same operating conditions, par allel-flow arrangement leads to higher plant capacities.