Solar, Biomass and Hybrid Dryers - BioEnergy Discussion Lists

The main advantage of using the gasifier stove is that the dryer can be operatedcontinuously for several hours with a steady heat input, with minimum attention.This dryer is constructed of bricks and mortar, and is more efficient than aconventional solar cabinet dryer made of steel or aluminum.The hot flue gases from the biomass gasifier stove are used to heat the process airinside the drying chamber, using a pipe heat exchanger and an automatictemperature control mechanism that allows the temperature of air inside the dryingcabinet to be maintained in the range 55-65°C.Design DetailsDrying ChamberThe drying chamber is 2m x 2m in cross-section and has a height of 1.95m. Thefoundation is made of 1m deep concrete pile. Figures 2.1, 2.2 and 2.3 illustrate thedryer. The drying chamber has brick walls on all four sides. The doors, as shown inFigure 2.3, were made of two layers of G.I. sheet with fiberglass insulation inbetween to reduce the heat loss; a narrow transparent area allows viewing of theproducts from outside during drying (Figure 2.1)130195200200200Dimensions are in cmFigure 2.1: Configuration of the drying chamber6