ASSESSMENT OF DRYER PERFORMANCE UNDER INTERMITTENT DRYING OF GRAINS IN FIXED BED

Resumo

Intermittent drying is an operation that aims to improve drying process performance with modulations of inlet air conditions such as its temperature and velocity, contrary to the conventional operation, in which air conditions are constant. This alternative operation aims to determine the best modulation pattern of air conditions to minimize energy consumption, maximize dryer performance or improve material quality. In this context, the objectives of this work are to simulate the drying process of some grains in fixed bed and assess if it is possible to enhance the dryer performance in terms of drying rates under intermittent operation in comparison with results obtained with conventional operation. Both intermittent and conventional operations were simulated with the same energy consumption related to the energy supplied by the air at the dryer entrance. Results revealed that the drying rates were higher under intermittence of inlet air temperature in comparison with results obtained under conventional operation with constant inlet air temperature. In addition, it was observed in some simulations that the amplitude and period values related to modulations can impact on drying rates.