The carrier fluid bed dryer is to put powder particles and paste (even suspension and solution) and other mobile materials on the airflow distribution plate such as perforated plate, and send the drying medium from the lower part with considerable speed. When the medium flow rate is low, the gas flows through the material particles, and the whole material layer does not move; gradually increase the airflow speed, the material layer begins to expand, and the gap between particles increases; then increase the airflow speed again, and a considerable part of the materials are suspended and form a gas-solid mixed bed, i.e. fluidized bed. Because the suspended materials in the fluidized bed are very similar to boiling liquid, it is also called fluidized bed, and it presents the properties of fluid in many aspects. For example, it has an obvious upper interface and remains horizontal; if the air flow velocity is increased, almost all particles will be taken away by the air flow and become gas transportation. Therefore, the air flow velocity is the most fundamental control factor of the fluidized dryer. The appropriate air velocity should be between making the material layer begin to fluidize and bringing the material out.
Over the years, fluid bed dryer have many applications in industry. Here are various materials dried by dryers.
(1) Single layer cylindrical fluidized bed
Used for drying ammonium sulfate, ammonium chloride, anhydrous sodium sulfite, table salt, polytetrafluoroethylene, calcium gluconate, alkaline violet dye, catalyst particles and other materials.
(2) Multilayer cylindrical fluid bed dryer
Carrier fluid bed dryer is used for drying polyester chips, sodium salicylate, aminopyrine, oxytetracycline, aureomycin, tetracycline, tablet starch granules, sugar powder and other materials.
(3) Horizontal multi chamber fluid bed dryer
It is used for drying PVC resin, polypropylene resin, nylon 1010, o-chlorobenzoic acid, tetracycline, oxytetracycline, chloramphenicol, syntomycin, liver meal, powdered sugar, S.M.P, A.P.C and other materials.
(4) Fluidized bed with agitator
Carrier fluid bed dryer is used for drying ammonium sulfate, copper sulfate, sodium fluoride, amino acids, casein, polypropylene resin, phenolic resin and other materials.
(5) Inert particle fluidized bed
It is used for drying titanium dioxide, pesticide mancozeb, pigment, dye, diatomite, sodium humate, humic acid and other materials.
(6) Vibrating fluidized bed
It is used for drying sugar, asbestos ore, milk powder and other materials.
(7) Spray fluidized granulation drying
Carrier fluid bed dryer is used for drying urea, glucose, sodium bromide, potassium bromide, ammonium bromide, titanium dioxide, sodium malonate, fluorescent brightener, potassium acetate, calcium chloride, ammonium nitrate and other materials.