Drying kinetics study of irregular fibril materials in a “differential” laboratory rotary dryer: Case study for cut tobacco

Research on the Physical Properties of Cut Tobacco under Different Storage Conditions

“…Cut tobacco moisture activity refers to the ratio of the equilibrium vapor pressure of cut tobacco in a closed space to the saturated vapor pressure of pure water at the same temperature [12]. It reflects the state of moisture presence and indicates the degree of moisture binding with cut tobacco [13]. The response surface model of cut tobacco moisture activity under different humidity and time conditions at the same temperature is shown in Fig.…”

Simulation of Heat and Mass Transfer of Cut Tobacco in a Batch Rotary Dryer by Multi-Objective Optimization

“…Cut tobacco from the top leaves with a moisture content of 22.5 ± 0.1% (wet basis) was used in this study (28). The drying experiments were carried out in a batch rotary dryer (Xiamen Yingde Industry and Trade Co. Ltd., Fujian, China).…”

“…Herein, m t (kg) is the mass of dried cut tobacco, t is the drying time (s), X (kg•kg -1 ) is the cut tobacco's moisture content on dry basis, h m (m•s -1 ) is the mass transfer coefficient, A (m 2 ) is the surface area of cut tobacco for mass transfer, ρ v,sat (kg•m -3 ) is the saturated vapor concentration corresponding to the cut tobacco temperature T t (K), ρ v,b (kg•m -3 ) is the vapor concentration of bulk drying air, and ΔE v (J•mol -1 ) is the apparent addi-tional activation energy. More details of the REA model can be found in the literature (28). The simulation results of the REA model are also discussed in this study.…”

“…This method considered the drying process as a chemical reaction, and the kinetic parameters of the drying process were obtained through experiments. LI et al designed a batch rotary dryer to study the drying characteristic of cut tobacco (28). The REA model was well validated by experimental data at various wall temperatures, which illustrated that the REA model could well simulate the drying characteristics of cut tobacco.…”

“…It was difficult to evaluate whether the heat transfer coefficient or the mass transfer coefficient is optimal. This study uses experimental data from LI et al (28), it focuses on the development of a simpler and more easily comparable heat and mass transfer model to simulate the drying process of cut tobacco in a batch rotary dryer. Six different models of equilibrium moisture content were selected to calculate the driving force of mass transfer, and a mathematical model of heat and mass transfer was numerically solved by using multi-objective nonlinear optimization.…”