In conveyor biomass dryer, the feedstock is spread onto a moving perforated conveyor to dry the material in a continuous process. Fans blow the drying medium through the conveyor and feedstock, either upward or downward. If multiple conveyors are used they can be in series or stacked (i.e. “multi-pass). Conveyor dryers are very versatile and can handle a wide range of materials.
The material is introduced into a flowing stream of hot air in an enclosed chamber. It is carried upward by the air and then cascades back to the bottom to be lifted again. Material is drawn out through openings in the side of the chamber
In flash dryer, the feedstock is suspended in an upward flow of the drying medium, usually flue gas. Flash dryers are appropriate for drying a wide variety of materials. Flash dryers are generally cost-effective only at larger scales. Electricity used by flash dryers is greater than that of other dryer types because high air flows are required to keep the material suspended. Flash dryers require a small particle size and so shredders may be required, also increasing electrical use.
