The document discusses fluidized bed drying, including its principles, construction, operation, advantages, and applications. Fluidized bed drying involves suspending solid particles in a stream of hot air or gas, allowing for uniform and rapid drying through direct contact between particles and air. Key parameters that can be controlled include temperature, humidity, feed rate, and particle size. Advantages are shorter drying times, uniform drying, and less thermal degradation compared to other methods. Applications include drying granules and powders in pharmaceutical manufacturing.