BOLZ-SUMMIX conical screw mixers and dryers work according to the proven principle of a rotating mixing screw being guided along the wall of the conical vessel at constant close distance by means of an orbital arm. The mixing screw moves through the product and transports it from the bottom of the vessel towards to top. The product is constantly moved upwards along the container wall by the Archimedes-Screw principle. At the same time gravity pulls the product down along the opposite wall and in the centre, outside the effective range of the mixing screw (convective gravity mixing).. As the rotating orbit arm guides the mixing screw along the wall, a slightly horizontal force results, and thus three-dimensional product flow, giving intense yet gentle mixing.
The gentle mixing is maintained by a displacement of particles against each other by lifting of product by the mixing screw, the imbalanced continuous descending of product in the centre by gravity and the slow radial orbital movement of the arm.
As only a selected, part of the entire batch is mechanically agitated and lifted by the mixing screw, shear applied to the product particles, the resulting wear and attrition, as well as finally the drive power required, are comparatively low and energy saving.