Studies on aeration with refrigerated air—III. Chilling of wheat with a modified chilling unit

Two trials on the cooling of grain with refrigerated air are described. The chilling unit had the fan positioned after the evaporator to lower relative humidity of the cooled air entering the grain. A bin containing 699 metric tonnes of wheat was cooled in summer from 30–37°C to 18–19°C in 160 hr at an energy consumption of 4·6 kW/hr/tonne. The second bin containing 863 tonnes of wheat was cooled in winter from temperatures of up to 42°C to 15–21·5°C in 236 hr at an energy consumption of 4·7 kW/hr/tonne. It was shown that grain was not moistened as a result of cooling. The importance of controlling both air temperature and humidity in the cooling system are discussed and this method is compared with aeration using ambient air.