Development Of A New Vegetable Dryer Model And Study On Its Drying Technology

A new recirculating drier model was designed and developed. Its drying technology was studied by means of dehydrating cabbages, fresh kidney beans, hot peppers, apples, and Chinese onions. The influences of drying medium temperature, velocity of wind, and dried quantity to the drying effects were analyzed in cabbage as an example. Mathematic drying model was established by quadratic cross rotary design method. The best combination of the parameters was air temperature at 60℃, wind-velocity at 1.95 m/min, dried quantity at 3.6kg/m2, and unit energy consumption was only 0. 6 Kwh/H₂O. Experimental results indicated that the drier model had the following distinguishing features: 1) its designation was scientific, reasonable, and original in the aspects of efficient dehumidification, accurately quantitative wind-provide, and wind changer. 2) it was highly automatic and easy to operate under computer control. 3) in the test of cabbage dehydration, the unit energy consumption was decreased from 1.39-1.86KWh/Kg-water in heat wind drier under normal pressure to 0.6-0.7KWh/Kg-water in the new model. The new model had significant energy-saving effects and high thermal efficiency. 4) the dried products from the new dryer model were safe, clean, with less loss of nutrition, and their color, smell were well kept, therefore their quality was promoted. 5) the dryer model structure was simple, reasonable, and small-sized. Medium R134a was used and less harmful to environment. Climate had no affects to its drying process. Its investment and running cost were much lower than that in other dryers with no heat wind.