Performance Analysis of Mixed Mode Solar Dryer for Tobacco Leaves ^†

Drying is a primary and suitable preservation method before storage for tobacco leaves to minimize mold/mycotoxin development. The drying temperature of leaves and stems of tobacco are 333 K and 348 K, respectively. The current study investigates the performance of a new type of mixed mode solar cabinet dryer for the purpose of drying tobacco. The proposed construction of cabinet dryer allows drying of tobacco leaves and stems in separate sections near to the desired temperature ranges. Numerical simulations of unsteady laminar airflow and heat transfer through a two-dimensional model was carried out for a typical day in August under the climatic conditions of Islamabad (Pakistan). Moreover, the effects of air inlet velocity and comparison of left and right drying sections of the solar cabinet dryer have been analyzed. Overall results indicated that the proposed design configuration was able to maintain required uniform temperature distribution in separate sections of the single cabinet dryer and, thus, offers promising results to keep the standard quality of the dried tobacco leaves and stems.