Fluidized Bed Dryers & Coolers
Materials processed in a Fluidized Bed Dryer or Cooler float on a cushion of air or gas. The process air is supplied to the bed through a perforated distributor plate and flows through the bed of solids at a sufficient velocity to support the weight of particles in a fluidized state. Bubbles form and collapse within the fluid bed of material promoting intense particle movement. In this state the solids behave like a fee-flowing boiling liquid. Very high heat and mass transfer rates are obtained as a result of the intimate contact between individual particles and the fluidizing gas.
Design
The design of the distributor plate ensures that the fluidizing gas is evenly distributed across the area of the bed. The gas velocity is such that only the very fine material fraction is carried over to the dust collection equipment. A high turndown ratio of production capacity is possible and fluctuations of the feed rate are easily absorbed. In most cases, there are no moving parts in contact with the product.
Design variations include:
Stirred Fluid Beds
Deep Fluid Beds
High Temperature Fluid Beds
Contact Tubes and Plates
Multiple Zones and Stages
Integral Drying/Cooling
Features
Provides extended residence times
Provides intimate contact between drying/cooling gases and products
Multi zones, velocities, temperatures, drying & cooling
Option for easily removable bed plates
Can be designed for open circuit partial gas recycle and SSD
Plug flow or well mixed
Can be designed with straight sides or with an expanded canopy
Flexibility of residence time and temperatures