subject: Continuous Flow Fluid Bed Dryer [print this page] A continuous flow fluid bed dryer has a dryer housing having a drying chamber and a plenum chamber located beneath the drying chamber. Moist product to be dried is introduced to the drying chamber at a product inlet and proceeds through the drying chamber to a discharge housing. A porous screen partially separates the drying chamber and the plenum chamber. Heated air is introduced into the plenum chamber which then passes through the screen to the drying chamber to dry product in the drying chamber. A shaft extends centrally through the drying chamber and is mounted for slow rotation therein. A plurality of paddles are connected to the shaft. The paddles move about a path of rotation whereby paddle ends sequentially sweep over the surface of the screen. In doing so, the paddles momentarily move product away from the screen permitting a rush of heated into the drying chamber locally fluidizing the bed and further drying the product. The product is treated very gently in the process so as to suffer minimal degradation if any.
The invention pertains to a continuous flow fluid bed dryer wherein portions of the bed are momentarily fluidized for drying purposes. The dryer includes a dryer housing having a dryer drum with a drying chamber, and a plenum section with a plenum chamber located beneath the drying chamber. Hot air is introduced into the plenum chamber. The lower part of the drying chamber is trough shaped with a curved bottom and relatively high side walls. A curved porous screen is located at the bottom of the drying chamber and permits hot air to be transferred from the plenum chamber to the drying chamber. A rotor shaft extends longitudinally through the drying chamber and carries a plurality of paddles. The shaft rotates slowly in the drying chamber to gently mix the product with the heated air and advance it downstream in the chamber. As each paddle sweeps across the screen it moves product away from the screen. This permits a momentary rush of air through the screen, locally fluidizing the product and promoting drying.
A continuous flow fluid bed dryer for drying of particulate product, comprising: a dryer housing having a dryer drum and a plenum section located beneath the dryer drum; said dryer drum being U-shaped with vertical side walls and a trough shaped bottom defining a longitudinal drying chamber; said dryer drum having a product inlet at an upstream end of the drying chamber, and a product outlet at a downstream end of the drying chamber; said plenum section defining a plenum chamber located beneath the drying chamber of the drying drum; a curved porous screen comprising at least a part of the bottom of the dryer drum permitting air flow from the plenum chamber to the drying chamber; a heated air inlet to the plenum section for introduction of heated air into the plenum chamber for movement through the plenum chamber to the drying chamber;
