Working principle of drum dryer

       The rotary drum of a drum dryer is a slightly inclined and rotatable cylinder, where wet materials enter from the upper part of one end and dry materials are collected from the lower part of the other end. Hot air enters from the feed or discharge end and is discharged from the upper part of the other end. The cylinder is equipped with a forward cutting plate, which continuously picks up and sprinkles materials during the rotation process of the cylinder, making them fully in contact with the hot air flow to improve drying efficiency and move the materials forward. The heat source for drying materials is generally hot air, high-temperature flue gas, water vapor, etc.

       The working process of a drum dryer is as follows: the material liquid that needs to be dried flows from the high-level groove into the receiving groove of the drum dryer, and the material is thinly (in the form of a film) attached to the surface of the drum by the film distribution device. The drum is filled with heating medium, and steam is commonly used in the food industry. The pressure is generally 0.2-6MPa, and the temperature is between 120-150 ℃. The material is vaporized by heat transfer from the drum wall during the rotation of the drum. The drum completes the processes of film distribution, vaporization, dehydration, etc. in one rotation cycle. The dried material is scraped off by a scraper and transported to the finished product storage tank by a screw, and finally crushed or directly packaged. The water evaporated during heat transfer can be introduced into the corresponding treatment device through a closed cover to capture dust or discharge according to its properties.