Vibration Fluidized Bed Dryer, abbreviated as VFD, is a new type of fluidized bed drying equipment suitable for drying granular and powdered materials. It boasts advantages such as ease of operation, energy saving, and environmental protection. The VFD has gradually developed and expanded its application over the past decade and is increasingly becoming the main model in drying equipment. The VFD is a new drying unit that applies a specific vibration source to a conventional fluidized bed dryer. This vibration source can be categorized according to its excitation method, including electric motor, electromagnetic induction, crank or eccentric wheel, pneumatic or hydraulic methods, etc.
The operation of fluidized bed has advantages such as good mixing of solid particles, a large heat and mass transfer area between gas and solid phases. However, its main shortcomings are: 1) The particles to be processed should be larger than 50-100μm, otherwise, it is prone to form channeling and dead zones; 2) There is severe entrainment when the particle size distribution is wide; 3) It is easy to form lumps or agglomerates when the particle temperature is too high; 4) Non-spherical particles such as wheat grains, fibers, and slices cannot be well fluidized.
*High drying efficiency, even drying, high yield, suitable for continuous production of the same type, with the added benefits of lower temperature, easy operation, and small land occupation. However, the drying chamber is not easy to clean, especially not suitable for drying colored particles, and there is a high proportion of fine powder after drying. In accordance with the aforementioned meaning, when hot air is used as the fluidizing medium in drying food wet materials, the hot air serves both as the fluidizing medium and the drying medium, performing dual functions. The material to be dried is, in the hot air stream, lifted, tumbled, mixed, and frictionally collided with each other, while also undergoing heat and mass transfer, thereby achieving the drying objective.
