When optimum heat transfer efficiency is required for the drying process, the Swenson fluid bed dryer is the best choice.
The fluid bed dryer features a stationary, upright shell through which heated air is forced and/or induced by a blower arrangement. Material enters the system through a feed chute or screw feeder and is fluidized by the heated gas stream. This produces a high degree of intermixing and intimate contact of the material and the drying media, resulting in optimum heat transfer efficiency.
The hot gases used for drying can be generated by either steam coils or a combustion furnace. These gases enter the plenum chamber and are evenly distributed across the body of the dryer by a perforated plate. The holes in this plate are covered with caps which prevent material from entering the plenum when the dryer is not in operation. The vent gases are exhausted through a dust collector for maximum recovery of fines.
The dry product overflows an adjustable weir plate and is discharged continuously though a rotary air lock.
The fluid bed dryer is typically operated in an open cycle configuration but can be operated in a closed cycle with the addition of a solvent recovery system and the use of an inert gas, such as nitrogen, as the drying medium. Vent gases leaving the fluid bed dryer are cleaned by a cyclone or fabric collector. A condenser is used to recover the solvent. The cooled, saturated gases are then reheated in an indirect-fired air heater or steam coils prior to entering the dryer.