DEVELOPMENT AND PERFORMANCE EVALUATION OF MILK PASTEURIZATION UNIT

Abstract

The main objective of the present investigation was to use the modern technological modifications for the milk pasteurization process. The original milk pasteurization unit was developed especially for the present work by adding a pneumatic regulating valve to improve its performance. The performance of the milk pasteurization unit before and after development was experimentally studied under four different heating temperatures (70, 74, 77 and 80oC), four different vapor pressures (200, 400, 600 and 800 kPa) and four different cooling temperatures (3, 4, 5 and 6oC). Evaluation of the milk pasteurization unit was carried out taking into consideration pasteurization unit productivity, heating rate, fuel consumption, energy requirements, bacteria count and final product quality. The experimental results revealed that pasteurization unit productivity (258 kg/hr.), heating rate (4.9oC/s) fuel consumption (144 l/hr.), energy requirements (1.74 kW.hr./kg ) and bacteria count (35), were in the optimum region under conditions of using the developed milk pasteurization unit at 74oC heating temperature, 400 kPa vapor pressure and 4oC cooling temperature.