ABSTRACT
Thermal processes involving the transfer of heat from one point to another are often encountered in the food industry, as in other industries. The heating and cooling of liquid or solid food products, the evaporation of water vapors, and the removal of heat liberated by a chemical reaction are common examples of processes that involve heat transfer. Convection is the heat transfer mode that takes place within a fluid by mixing one portion of the fluid with another. The heat transfer of heat through solid objects is by conduction alone, whereas the heat transfer from a solid surface to a liquid or gas takes place partly by conduction and partly by convection. Newton’s law of cooling states that the heat transfer from a solid surface to a fluid is proportional to the difference between the surface and fluid temperatures and the surface area.
