The results of experiments on the optimal method of heat-transfer agent supply for sprouted grain drying

BACKGROUND: Sprouted grain is a valuable vitamin feed additive, but high moisture does not allow it to be stored for a long time. To ensure the storage of sprouted grain for up to several weeks, it must be dried to a final moisture of 13–15%. The industry does not produce technical means for drying sprouted grain. AIM: Choosing the optimal method of supplying ambient air or a drying agent to reduce the energy consumption of the drying process and to increase the drying rate of sprouted grain. METHODS: The proposed dryer, which has the ability to remove moisture from sprouted grain by directing a flow of ambient air or a drying agent over the sprouted grain, as well as through a layer of sprouted grain, to the product, was used. The experiments were conducted to determine the minimum energy consumption and maximum drying rate. Temperature sensors were used to assess the temperature of the drying agent or ambient air inside the drying chamber. An electric meter was used to measure electricity consumption. The drying time was determined using a timer. The initial and final moisture of the product was determined using a drying cabinet. RESULTS: When using the proposed dryer, the optimal method of supplying the drying agent to the sprouted grain was determined. The values of the minimum energy intensity and maximum drying rate of sprouted grain are obtained. During the drying of the sprouted grain, the initial moisture was 50–54%, the final moisture after drying was 12.5–14.7%. Experimental dependences of energy intensity on the drying rate were obtained, taking into account the method of supplying ambient air and drying agent to the sprouted grain. CONCLUSION: As a result of drying, the lowest energy consumption was obtained with the option of supplying the drying agent through the product layer, Ес=3.92–4.08 kWh/ kg, the highest drying rate with the option of supplying the drying agent through the product layer, Vс=0.35–0.37 kg/ h. Therefore, from the considered methods for sprouted grain drying, taking into account the rate and energy intensity of drying, the supply of a drying agent through the product layer is chosen.