Rototherm-D operating principle
The Feed, being moist powder or bulk solids, enter into the Rototherm-D at one end. The horizontal shell and the specially designed rotor are heated by water, steam, or hot oil. The low speed helical mixing bars agitate the product continuously, while gently churning and continuously conveying it to the discharge end of the dryer in a plug flow manner.
Vacuum minimizes drying temperature and avoids thermal degradation of heat sensitive materials. An adjustable weir at the discharge end keeps the product level in the dryer between 25% and 75% full.
Adjusting the height of the weir or changing the feed rate will allow to control the residence time. The dry product discharge is collected either by batch in a sealed vessel or continuously after passing through a vacuum lock vessel.
- Low temperature and shear reduce product degradation
- Continuous process eliminates variations in product quality between batches
- High heat transfer area-to-volume ratio
- Adjustable drying time from 20 minutes to several hours
- Drying heat sensitive powders and bulk solids
- Drying shear sensitive powders and bulk solids
- Diffusion controlled drying applications
- Further dewatering readily dried sludges and press-cakes
- Sublimation of powders
- Solid state polymerization/polycondensation