Working principle of fluidized bed

Vibration fluidized bed dryer, abbreviated as vibration fluidized bed, is a new type of fluidized bed high-efficiency drying equipment suitable for drying granular and powder materials. It has advantages such as easy operation, energy conservation, and environmental protection. Vibration fluidized bed is a new type of equipment that has gradually developed and expanded its application in the past decade, and is increasingly becoming the main type of drying equipment. A vibrating fluidized bed is a new type of drying device that applies a specific vibration source to a regular fluidized bed dryer. This vibration source can be divided into electric motor method, electromagnetic induction method, crankshaft or eccentric wheel method, pneumatic or hydraulic method, etc. according to its excitation method.

Fluidized bed operation has the advantages of good solid particle mixing and large heat and mass transfer surface area between gas and solid phases, but its main shortcomings are:

① The processed particles should be greater than 50-100 μ m. Otherwise, it is easy to form gullies and stagnant areas;

② When the particle size distribution is wide, the entrainment is severe; 

③ When the particle temperature is high, it is easy to form clumps or agglomerations; 

④ Non spherical particles such as wheat grains, fibers, and chips cannot be fluidized well.

A vibrating fluidized bed is a very successful modified fluidized bed, which is supported on a set of springs and powered by an excitation motor. The loose material put into the dryer is thrown towards the outlet end by the excitation force on the porous plate and transported towards the VI end. The hot air is blown in from the porous plate and passes through the material layer, transferring heat to the material and carrying the vaporized water from the material to be discharged through the exhaust port, thereby drying the material. Due to the mechanical vibration of materials in a vibrating fluidized bed, they are in a moving state. Dynamic drying can be achieved by simply blowing in an appropriate amount of hot air, resulting in high thermal efficiency and uniform material drying.