The influence of various layouts of internal baffles on air distribution in heat pump cabinet dryers

Abstract

Cabinet dryers are commonly employed in the food industry due to their simplistic design and low operational maintenance. Nevertheless, uneven internal airflow remains a critical issue affecting efficiency. This study developed nine models of heat pump cabinet dryers, based on traditional designs, and conducted a numerical investigation using Computational Fluid Dynamics (CFD) modeling. Modifications were made to the positions of the air inlet, outlet, and the baffle angle to determine the configuration that achieves the most uniform drying airflow, aiming to improve overall dryer performance. Key factors such as airflow velocity, temperature, humidity, and heat and mass transfer were analyzed. The results demonstrated that the optimized configuration, featuring a top inlet, middle outlet, and 4° baffle angle, improved flow and temperature uniformity by 52.70 % and 85.32 %, respectively, compared to the original design. The effectiveness of this configuration was validated through experimental trials involving the loading and unloading of figs. Physical property assessments indicated satisfactory drying uniformity, while sensory evaluations showed the final product was crisp, easy to chew, and exhibited enhanced sweetness. Overall, this study highlights the effectiveness of structural modifications in improving airflow and temperature uniformity, thereby enhancing the overall drying performance.