Tunnel-type continuous multi-physical field drying equipment: Design, numerical simulation and application

Abstract

In this study, a tunnel-type continuous multi-physical field drying equipment was developed to combine microwave, hot air, and infrared drying technologies. The microwave source arrangement and hot air equalizing plate were optimized based on numerical simulation to enhance the uniformity of the microwave field and hot air velocity distribution. Mode 4 and opening ratio 37.70% (r = 60 mm) were had the highest electric field distribution and hot air distribution. This equipment was further used to pre-dehydrate cowpeas and the effects of microwave, hot air, and infrared on food drying properties and quality of dried samples were investigated. The results showed that the moisture content was reduced by 20% and the ΔE value greater than 5 after pre-dehydration. Microwave treatment rapidly reduced the moisture content of cowpeas. The infrared treatment significantly improved the uniformity of temperature distribution and the texture profile of the dried sample. The hot air drying increased 10 °C for the overall temperature of the food material and balanced the internal water content of the food material. This study aims to provide future researchers with insights to develop novel microwave-based continuous drying equipment for its commercial applications.

Keywords:

• Tunnel type
• microwave drying
• infrared drying
• physical field
• cowpea

Disclosure statement

No potential conflict of interest was reported by the authors.

Additional information

Funding

We acknowledge the financial support provided to us by Jiangsu Province and Education Ministry Co-sponsored Synergistic Innovation Center of Modern Agricultural Equipment (XTCX2019) and the National Natural Science Foundation Project of China (32372011), both of which have enabled us to carry out this study.