The research of a cow's milk refrigeration unit for the conditions of mountain pastures of the North Caucasus

The issue of cooling cow's milk in the mountain pastures of the North Caucasus is considered in the article. The cooling method is based on the use of mountain river water adjacent to the pastureland of the livestock center as a working fluid in the cooling process. A cooling plant has been developed, which is part of the technological equipment of a milking center for mountain pastures. The optimization of the main parameters of the milk cooling plant in laboratory and production conditions was carried out. The equipment for carrying out a laboratory experiment with an imitation of the working fluid - the water of a mountain river - was selected. It was revealed that the following parameters influence the final temperature of milk: the speed of the cooling water Vow; the ratio of the diameter to the length of the tank of the refrigeration plant Кс=D/L and the duration of milk cooling Tom. To conduct multifactorial experiments, a matrix of the three-level Box-Benkin plan was compiled. To determine the optimal design parameters and operating modes of the refrigeration unit, which creates the required milk temperature, a multifactorial experiment was carried out. Testing the reproducibility of the experiment was carried out by the Cochran criterion. Analysis of the results of the multifactorial experiment revealed - the minimum value of the optimization criterion - the temperature of chilled milk 5 °С - is achieved by certain values of variable factors: cooling water velocity VОВ = 0,48 m/s; the ratio of the diameter to the length of the reservoir КС=0,5; duration of milk cooling TОМ = 1214 s. Calculations for the process of cooling freshly milked milk to a longterm storage temperature satisfy the general requirements for storing drinking high-grade milk. The prototype of a milk refrigeration plant using the energy of a mountain river was successfully operated in the mountain pasture of the Zolsky district of the Kabardino-Balkarian Republic.