Thermal Optimization of a Spiral Freezer

Abstract

Energy conservation is an essential step towards mitigating the issues of energy crisis and degradation of environment. The use of excessive energy and losses in energy are generally associated with industrial growth worldwide especially in the industry related to food processing, where a considerable amount of energy is being consumed. Thus there exists an enormous potential for efficiency improvement in the existing energy-consuming equipment. Freezing and hardening are important energy intensive steps in ice cream manufacturing for which a Spiral Freezer is used. Spiral freezing enables products to be frozen either individually or in batches. The ‘spiral’ is a vertical conveyor where products pass through a continuous freezing process. A tube and fin air-cooled heat exchanger evaporator is used for the refrigeration process. In the present study, the air cooled heat exchanger is designed and optimized using HTRI Software for the refrigeration system used in a Spiral Freezer. Also the freezing time is estimated for various shapes of ice-cream box products using ANSYS Fluent transient analysis and compared with the analytical solution. The pressure drop of the system is calculated analytically and compared with the results that are obtained in ANSYS Fluent.