Experimental Study on Variation Characteristics of Pressure Drop and Process Optimization for Corn Kernels During the Hot Air Convective Drying Process

To reveal the variation characteristics of the pressure drop during the corn hot air drying process and provide some reference for designing the drying process, a pressure drop model focusing on the dynamic drying process was established based on the response surface methodology and the variation characteristics of the pressure drop has been analyzed in the present work. In detail, a corn convective drying apparatus was established, and a center rotation regression experiment was conducted followed by a Box–Behnken design by considering hot air temperature (T), corn flow velocity (vc), air velocity (va), and thickness of the materials layer (L) as independent variables while and the pressure drop (δP) was considered as the dependent variable. The results show that the va has the most significant impact on the δP, followed by L, vc, and T. The established model δPRSM shows a better fitting and prediction performance (R2 = 0.969, Cook’s distance < 1) than that of commonly used models. In addition, the minimize δP was determined as 368.392 Pa, and the corresponding drying conditions are T of 60 °C, vc of 0.06 m/s, va of 0.2 m/s, and L of 500 mm, and the hot air temperature should be within 72 °C, which can form the basis for designing the corn hot air drying process.