Heated air drying and low-temperature drying

postharvest-heatedairdrying-table

Heated air drying and low-temperature drying (also referred as in-store dyring or near-ambient drying) employ two fundamentally different drying principles. Both have their own advantages and disadvantages and are sometimes used in combination e.g., in two-stage drying.

Heated air drying employs high temperatures for rapid drying and the drying process is terminated when the average moisture content (MC) reaches the desired final MC. While, in low-temperature drying the objective is to control the relative humidity (RH) rather than the temperature of the drying air so that all grain layers in the deep bed reach equilibrium moisture content (EMC). The figure on the right shows the major differences.

Content experts: Martin Gummert and Joe Rickman