The boiling dryer is also called a fluidized dryer, and is composed of an upright cylinder and one or several porous distribution plates at a certain height below the cylinder. The drying medium (hot air) is fed from the bottom of the simplified body, and the material having a thickness of 10 to 100 mm uniformly distributed on the distribution plate is dispersed to form a suspension fluidized layer. When the airflow speed is low, the material layer does not move, the gas passes through the intergranular space of the material layer, continues to increase the airflow speed, the material begins to loosen, the bed expands slightly, the material exchanges positions in a certain interval, and then continues to increase. At the velocity of the gas stream, the material is suspended to form a fluidized layer. In the fluidized layer, the materials are turned up and down in the hot gas flow, collide with each other, and heat and vaporize between gas and solid to achieve the purpose of drying. RUNDE speciallized in bronze fittings,covered end feed and solder type and the flange,Bronze Fittings.well known as yorkshiire bronze fittings,pegler bronze or gunmetal fittings as well as connex bronze fittings bronze fittings,Yorkshire bronze fittings,Pegler bronze fittings,gunmetal fittings Taizhou Runde Company , https://www.zjbrassfittings.com
The main factor affecting boiling drying is the speed of the drying medium. When the height of the static material layer is 5 to 150 mm and the particle size of the material is more than 0.5 mm, the suitable gas flow rate should be taken at the critical flow rate of the material fluidization and carried by the gas flow. Between the speeds of the particles, that is, the free settling velocity of the material 0.4 0 is 0.4 to 0.8 times. Because when the material layer expands to a certain height, the void ratio of the bed increases, and the airflow velocity decreases. As the airflow velocity decreases, the material falls back to form a fluidized layer, and when the airflow speed increases to equal the freedom of the material. At the settling speed, the material is blown out from the top of the dryer. Therefore, the suitable air flow rate for boiling and drying should be between the critical fluidization speed and the take-off speed.
Boiling drying has the advantages of high heat transfer and vaporization speed and large heat transfer contact area. The structure of the dryer is simple, the cost is low, and the operation and maintenance are convenient.
At present, the boiling dryers used in China have several types of single-layer cylinders, multi-layer cylinders, and horizontal multi-chambers. As shown in Figure 1, Figure 2 and Figure 3. 
March 17, 2024