Drying Performance of a New Type Drying Equipment

Abstract

By-product of tofu contains useful ingredients as well as water but it begins to smell quickly. Then it becomes industrial waste, but if it is dried, powders suitable for food material are obtained. A new type drying equipment is proposed for that purpose. It is composed of air heater, drying drum, classifying chamber and cyclone separator. Ceramic balls about 5 mm diameter are contained in the drying drum and move about at high speed entrained in the hot air. Wet materials are added to the drum by rotary feeder, dispersed by the action of balls and conveyed by the gas stream. At steady operating condition, fuel flow rate, air flow rate, temperature and humidity are measured. Drying is done mainly in the drum and partly in the classification chamber according to the obtained temperature drop. The measured humidity agrees well with the predicted value from the mass balance of steam. The energy used for evaporation of water in the material was about 80% of the provided energy. This dryer has the ability of drying wet materials in short time, continuously and efficiently without burning the material. But its drying capacity is relatively small and enlargement is necessary for industrial use.