The batch dryer operates by forcing hot air through 5 to 10 product beds. New product is continuously fed to the top bed deck which transforms the continuous flow into a series of batches. Discharging from each bed deck is timer driven and powered by hydraulic cylinders. Discharging starts at the lowest deck and sequentially moves through the upper decks to assure there can be no product cross contamination.
Every product batch is treated individually in separated drying zones. The amount of evaporation can be controlled on each deck by variations of the drying air volume and temperature. A moisture sensor at the dryer outlet can serve as an input for the heater temperature setpoint to improve final product moisture control.
A controlled volume of drying air is exhausted with a high relative humidity while the remaining air is recycled back to the heaters. This maximizes the energy efficiency of the Geelen Counterflow dryer.