Flow field optimized design and simulation of steam blanching and hot air drying chamber

Blanching and drying have been widely used to process agricultural products. Some changes can be induced in the cellular structure of products exposed to the high temperature and humidity, particularly for the subsequent processing, such as peeling, sterilization, preservation, and drying. The quality of agricultural products can be enhanced to extend their shelf life and storage period, thereby increasing their added value and market competitiveness. Among them, the steam blanching and hot-air drying cabinet can also serve as innovative drying equipment to combine the functions of blanching and drying for agricultural products. Green and low-carbon working can be adopted to efficiently handle the processing needs of agricultural products. This intelligent drying equipment is equipped with automatic control and monitoring functions, thus enabling real-time monitoring and adjustment of internal temperature and humidity. The quality and safety of agricultural products can be improved during blanching or drying. Additionally, energy-saving and environmental protection can be used to effectively reduce energy consumption and emissions, fully meeting the requirements of sustainable development. Therefore, the steam blanching and hot-air drying cabinet shared the broad application prospects for agricultural products. A green, efficient, and intelligent drying solution can also be provided for the agricultural processing industry. The high quality of agricultural products can depend mainly on the uniform internal flow field in the blanching and drying cabinets, such as the velocity, temperature and relative humidity. This study aims to improve the field of internal velocity, temperature and humidity, in order to reduce the occurrence of condensation inside the cabinet. A mathematical model was established using computational fluid dynamics (CFD). Air supply was evaluated to determine the number of air supply ports for the agricultural products in the steam blanching and hot-air drying cabinets. The research results showed that the side supply and side return air supply were generally better than the top supply and bottom return air supply, in terms of the uniformity of the velocity field, temperature field, and relative humidity field. An energy utilization coefficient increased by about 18%. The condensation area on the inner wall of the cabinet was smaller than that of the top supply and bottom return air supply. Simulation studies showed that better uniformity of temperature and humidity was achieved inside the cabinet when the number of air supply ports was 4. The energy utilization coefficient was also the highest. The experiment showed that the maximum temperature deviation between the experiment and the simulation was 2.3 ℃, and the relative humidity error was less than 1.3% within a reasonable range. The finding can provide a strong reference for the low-carbon and intelligent drying of agricultural products.