Rice drying quality using gas-catalytic infrared equipment: an experimental study

Abstract Globally, up to 10% of the total annual rice production is wasted due to excessively high moisture content during storage. Mechanized drying of rice is an important measure to reduce this loss. However, traditional hot-air rice dryers have issues such as low drying rates and high energy consumption. This paper introduces a new type of gas-catalytic infrared rice dryer, including its working principle and components. By using drying rate and fissuring rate as evaluation indicators before and after drying, the performance of this dryer is compared with that of traditional hot-air dryers. Further, a three-factor, three-level orthogonal experimental method was employed. Batch processing capacity, conveyor belt speed, and tempering time were selected as variables to calculate the optimal operating conditions of the gas-catalytic infrared rice dryer using the comprehensive balance method. Experimental results show that under nine different operating conditions, the gas-catalytic infrared rice dryer outperforms the traditional hot-air dryer. The drying rate of the gas-catalytic infrared dryer increased by 215.15% compared to the traditional hot-air dryer, and the fissuring rate decreased by 86%. The orthogonal experimental results indicate that, based on a comprehensive evaluation of moisture content difference and fissuring rate, the gas-catalytic infrared dryer achieves the best drying effect when the conveyor belt speed is 1.92 m/min and the tempering time is 40 minutes. These research findings provide important references for further optimization of rice drying technology.