The infrared radiation and vacuum assisted drying kinetics of flue-cured tobacco leaf and its drying quality analysis

Dehydration is widely involved in tobacco processing such as tobacco leaf curing, tobacco trip redrying and cut tobacco drying, which plays a key role due to its effect on the physical and chemical quality of tobacco. The current drying methods in tobacco processing mainly use heat conduction, heat convection or their combination to dehydrate tobacco materials. However, radiation heat transfer as one of basic heat transferways has not been investigated in the tobacco drying. In the present work, infrared radiation dryer was designed to explore the tobacco infrared radiation drying characteristics. The effect of radiation heat transfer conditions and vacuum on the drying kinetics and temperature of tobacco leaves was investigated. Diffusion coefficient of middle tobacco leaves C2F is between 0.848×10-10 ~ 1.597×10-10 m2/s. At the same time, the pore structure andpetroleum ether tobacco extracts in dried tobacco were also analyzed in order to explore the different effects of infrared radiation drying and traditional drying technology on tobacco quality.   Keywords: Flue-cured tobacco; Infrared radiation; Vacuum; Dryingkinetics; Tobacco quality