Fluidized bed technology, as an advanced material handling method, is widely used in chemical, light industry, medicine, food, plastics, grain and oil, slag, salt, sugar and other industries. The core principle is that when the gas is evenly distributed through the pressure equalization distribution plate, it passes through the bed material, so that the material is suspended in the gas flow to form fluidization. This state not only maximizes the specific surface area between the material and the hot medium, but also facilitates homogeneous mixing of the material and an efficient heat and mass transfer process.
In a fluidized bed, the fluidized movement of the material significantly reduces the resistance to heat and mass transfer in the air film, thereby improving the overall thermal efficiency, which can typically reach 60%-80%. This efficient heat and mass transfer mechanism provides ideal process conditions for drying, cooling, and humidifying the material.
It is worth mentioning that the vibrating fluidized bed, as a modification of the fluidized bed, further improves the effect of heat and mass transfer by introducing mechanical vibration. The drying rate in a vibrating fluidized bed can be up to 15~2.5 times. This technology not only increases the drying speed in the constant speed drying stage, but also reduces the critical water content due to the introduction of vibrations in the reduced speed drying stage. The vibration adjusts the resonant frequency of the water in the solid capillary, which partially excludes the water bound in molecular form.
A standard vibrating fluidized bed is usually composed of three parts: a pressure equalizing bellows, a fluidizing section and a settling section. The heat energy is transferred from the hot air to the wet material surface in a cross-flow manner, and is heated and dried in the fluidization section. Wet materials are mixed and collided with each other under the action of hot air flow and vibrating force, which ensures full mass and heat transfer between wet materials and hot air flow. The material layer on the bed surface maintains a fluidized state with uniform directional movement, and the entrained particles are separated from the airflow in the expansion section and settle into the fluidized section. Finally, the dried finished product is discharged from the discharge port, while the exhaust gas is purified by equipment such as cyclone separators and discharged.
In summary, fluidized bed technology, especially the application of vibratory fluidized bed, has revolutionized the material handling industry. Its high efficiency, energy saving, and environmental protection characteristics make this technology widely used and recognized in many fields. With the continuous advancement of technology, fluidized bed technology will continue to play an important role in the field of material handling, providing strong support for the production and development of various industries.