Development and Industrial Application of Low Temperature Humidity Regulating Heat Pump Dryer for Drying Tilapia

The low-temperature operation condition of heat pump dryer is studied,the key technology of defrosting is broken through,and the treatment problem of evaporator frosting in low-temperature operation is solved.Compared with the traditional hot fluorine defrosting,the refrigeration capacity of this technology is increased by about 10%.In view of the low efficiency of low-temperature drying of tilapia,different pretreatment and temperature drying experiments were designed with tilapia as raw material.It was obtained that the switching point of low-temperature alternating cold and heat drying of tilapia was that the water content of the material was reduced to about 60%.5HBR-1000S low temperature humidity regulating heat pump dryer with batch output of 1 000 kg was developed by integrated defrosting technology.With low salt pickled tilapia as raw material,multi batch drying industrialization application test was completed,and the production capacity reached the design standard.The application results show that the set temperature is 5～10 ℃ and the relative humidity is 45% ～65%.It takes about 6 days to dry the semi dry fish,which improves the efficiency by 100% compared with the low-temperature drying at 5 ℃.The energy consumption per unit of water removal is 474.39 g/kW·h,which saves 15.44% energy compared with the traditional high-temperature drying with the same thickness specification,and it takes about 10 days to dry the fully dry fish.The main components of the tested products have reached the national standard of pickled aquatic products,and the industrial application effect is good.