Rotary Vacuum Dryer consists of cylindrical jacketed vessel with a central agitator having specially designed blades. In Rotary Vacuum Dryers the indirect heating is achieved by circulating hot water, Thermic oil or steam through the jacket. The agitator design is optimized so as to bring every particle in contact with the heated surface while rotating. This helps to achieve uniform temperature throughout the batch thereby preventing the re-condensation inside the drying chamber since there are no cold spots, and contributes to rapid drying speed and eliminates caking. A high vacuum is maintained, while the material is in motion permitting the drawing off of moisture or vapour under desired conditions.