Low cost Vacuum Rake Dryer environmental friendly

The Rake dryer is a horizontal, batch-type vacuum drying equipment featuring a cylindrical shell with a jacket. Inside the cylinder are a low-speed stirring shaft and rake teeth. After material is fed through the top inlet, steam, hot water, or thermal oil is circulated within the jacket to provide indirect heating. The rake teeth operate in a cycle of forward rotation—stop—reverse rotation, controlled by a time relay, continuously moving the material axially and constantly renewing its surface. Moisture evaporates under heat and is then removed by a vacuum pump. This design ensures high thermal efficiency, enabling the final moisture content of the dried product to be reduced to approximately 0.5%.

This equipment is particularly suitable for processing materials that are prone to oxidation, heat-sensitive, explosive, or containing organic solvents, and is widely used in industries such as chemicals, and food. Operation under vacuum lowers the boiling point of solvents, preventing oxidation and degradation of materials while facilitating recovery of volatile components. Its main drawbacks include relatively long drying times and lower production capacity due to batch operation, as well as a complex structure and higher cost, making it unsuitable for applications requiring frequent changes in product types.