Search Results (2)

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. Full article

Global waste production has raised recently due to numerous agricultural and industrial activities. Among other actions devoted to waste reduction, revaluation seems to be the most advantageous one from an environmental and economic point of view. In the olive oil sector, by-product management (namely olive pomace, olive mill wastewater, and sludge residue) poses serious problems for companies, with the energy use of these wastes being a feasible option to solve these problems. Due to their high moisture content, drying constitutes the main stage for a possible bio-fuel conversion. This research work deals with the analysis of drying for the three main wastes from olive oil by using a prototype dryer. This equipment has different working regimes depending on the kind of convection (natural or forced for passive and active mode, respectively), the incidence of solar radiation on the product (indirect or mixed type) and the use of an additional system for energy supply (hybrid type). From the results, it could be said that all the wastes were suitable for solar drying. However, drying conditions were different for each case. Olive pomace and olive mill wastewater showed promising results for solar drying application in mixed active mode. Concerning sludge residue, its special physical structure could employ the use of turners for drying, in order to improve heat transfer to the product. Moreover, hybrid active mode enabled a considerable reduction in drying time, being an aspect to take into account for its use during low solar radiation or at night time. Full article