Vegetable crop drying system - uses two-stage action, with predrying air warmed using waste heat from drying plant

摘要

A vegetable crop is dried in two stages, the predrying stage recovering waste heat from the main dryer. All available heat from the latter is consumed in the total drying operation, the predrying stage being effected using an air stream pased over layers of the vegetables. Air for the predrying stage is pref. heated by direct heat exchange with the exhaust gases of the dryer. Alternatively the preheating air can be warmed using a liq. as the heat carrier medium, the liq. being used to clean the exhaust gases.