Study On Parameter Optimization And Controlling Of Freeze Concentration Equipment

Volatile components lose and thermosensitive components denaturalization can be avoided in freeze concentration, so nutrition, quality and flavor of materials can be saved. Rotary cylinder freeze concentration equipment was discussed in this paper.The operation characteristics, performance parameters and evaluation index of freeze concentration are firstly discussed in this paper. Then changes of freezing point, mass of ice and liquid, useful component loss, relative velocity between ice and liquid, and quality change of liquid material were analyzed.Taking seawater as the typical liquid material, the relation of refrigerant evaporation temperature, seawater temperature, ice thickness, icing rate at the interface of ice and seawater were discussed, and a controlling method was also given to the equipment.An experimental equipment for simulating rotary cylinder freeze concentration was set up. A series of freeze concentration experiments were performed at different refrigerant evaporation temperature and seawater temperature. Experimental results fitted well with theoretical analysis, and they could be good basis for further study on freeze concentration.It shows that rotary cylinder freeze concentration equipment is energy saving, work continuously and concentrate liquid materials at low temperature. Through changing refrigerant evaporation temperature and solution temperature, ice formation rate and useful materials loss can be controlled. When refrigerant evaporation temperature is -1℃, seawater temperature is -5℃, freeze concentration period is 10 minutes, the thickness of ice outside the evaporator is 4.8mm, and the NaCl in ice is 0.65% with ice surface washed by fresh water.