Milk Powder is a processed dairy product made by evaporating milk to dryness. Drying extends the shelf life of milk apart from reducing the weight and volume and lowers the cost of transportation also. The initial solid in the milk varies from 7.5% to 12% depending upon type of milk and the final moisture in the powder, ranges between 2.5% and 5%. Since drying is an energy intensive process, Mithila Dairy, offers the solution to make the process energy efficient & cost effective.
Milk is concentrated up to 45-48% solid concentration in Multiple Effects Falling Film Evaporator with TVR/MVR System. Evaporation of water takes place under vacuum conditions and at low temperature. A Five Effect Falling Film Evaporator with TVR over 3rd effect will have specific steam consumption of 0.12 kg/kg whereas a seven effect plant with TVR over 4th effect gives specific steam consumption of 0.09 kg/kg which is equivalent to energy consumption in MVR evaporator.
During drying in spray dryer, the excess water present in free form between the particles of the dry solids gets evaporated easily. Whereas last stage of evaporation demands more energy as water contained in pores and capillaries of the solid particles need to be evaporated. These last drops of water are removed from milk solid in a Vibro Fluid Bed Dryer which requires less energy for removal of balance moisture.