Determination of food freezing conditions

Power inputs into production of farm products in Russia are much larger as compared to such inputs in EU developed countries. The increase of energy saving and power efficiency of technological processes of food factories is the basis for enhancing their competitiveness. Refrigeration processing of foods is one of the main links in the technological chain of food industrial production. Improvement and intensification of refrigeration processing are of great importance in preservation of agricultural raw materials and food products. Hence, the efficient selection of equipment providing energy saving conditions for the thermal treatment of raw materials is a topical problem for the specialists of the agro-industrial complex. The rational selection of equipment is founded on a science-based engineering methodology for calculating thermal processes, which is based on balance relations or differential equations describing the process in question. The application of these mathematical equations, in turn, implies a deep understanding of phenomena running in the processed product and their dependence on the thermophysical, geometric and flow parameters of the product and the cooling medium. It is shown in the work that one of the main characteristics of the product processing is its size, which influences deeply on the scale of the changes, expressed in the duration of the process on condition that the desired result is achieved. This work provides the mathematical models describing the freezing process, and the possibility of applying them for various foods. The criteria of choosing food freezing conditions were determined based on the features of the heat and mass transfer processes as well as industrial experiments. The classification of freezing processes according to their duration was offered. Nomograms for engineering calculation of freezing processes and selection of refrigeration equipment were developed.