Investigating the Effect of Different Combination Strategies of Hot Air and Infrared Radiation on Apricot Drying

Hot air drying is the most common method used to dry agricultural products; this method is time consuming and has high energy consumption. Also, due to the rapid drying of the product surface in this method, the distribution and transferring of heat and moisture inside the product is relatively uneven. In fruits, such as apricots, skin of the fruit has a controlling and inhibitory effect on the drying process. Therefore, using some combination methods to dry fruits such as apricots, can reduce drying time and energy consumption. In the present study, a convection dryer was equipped with an infrared radiation system. The effect of hot air and infrared combination in different strategies on apricot drying was evaluated and compared. Experiments were conducted with hot air and infrared treatments alone, simultaneously and in a combination of two-stage and intermittent infrared in a combined dryer on a laboratory scale. The hot air temperature was 65 ° C, the velocity of hot air was 1.5 m/s and the power of infrared lamps was 400 watts. The results showed that the drying time, energy consumption and effective moisture penetration coefficient were significantly affected by the treatments. Midili et al.'s model was able to describe well the drying behavior of apricots for all the different combination states under investigation.