ABSTRACT
A combined infrared (IR) and hot air drying system is an efficient and rapid drying method compared to the usage of IR and hot air drying separately. It has some advantages such as improved quality of dried product and good drying characteristics. Heat and mass transfer can take place more efficiently and, consequently, drying time dramatically reduces, energy efficiency increases, and specific energy consumption decreases. Because the temperature of the product being dried is kept relatively low during the drying process, thermal degradation of heat-sensitive products can be retained to a higher degree than by convective hot air drying. Therefore, it can be seen as an alternative to the drying of heat-sensitive products. From the final product quality perspective, it is observed that this method is superior to the separate use of IR and hot air drying. Also, energy and operating cost of the combined drying mode for several food and agricultural products is lower than convective drying systems, and optimal operating conditions for combined IR and hot air drying have been demonstrated by several researchers, the aim being to improve product quality and reduce operating and energy cost.
