Drying characteristics of barley grain dried in a spouted-bed and combined IR-convection dryers

A study was performed to determine the drying characteristics and quality of barley grain dried in a laboratory scale spouted-bed dryer at 30, 35, 40, and 45 degrees C and an inlet air velocity of 23 m/s(-1), and in an IR-convection dryer under an infrared radiation intensity of 0.048, 0.061, 0.073, and 0.107W cm(-2) at an air velocity of 0.5 m/s(-1). The results show that the first, relatively short, phase of a sharp decrease in the drying rate was followed by the phase of a slow decrease. The time of barley drying depended on temperature of inlet air in a spouted-bed dryer and on radiation intensities in an IR-convection dryer. Barley drying at 45 degrees C in a spouted-bed dryer was accompanied by the lowest total energy consumption. The average specific energy consumption was lower and the average efficiency of drying was higher for drying in a spouted-bed dryer. The effective diffusivities were in the range 2.20-4.52 10(-11) m(2) s(-1) and 3.04-4.79 10(-11) m(2)/s(-1) for barley dried in a spouted-bed and in an IR-convection dryer, respectively. There were no significant differences in kernel germination energy and capacity between the two drying methods tested.