MULTI-SCREW EXTRUDERS-MIXERS WITH MODULAR MIXING MEMBERS Russian patent published in 2000 - IPC

FIELD: multi-screw extruders- mixers with jointly rotating interengaged screws intended for plastic treatment. SUBSTANCE: multi-screw extruder-mixer has a body assembly and screws. The body comprises two sections adjoining each other and having the shape of a circular cylinder, each section has an internal wall. The screws are located inside the sections of the extruder cylinder and made for rotation in the same direction about the axis of rotation. Each screw comprises a great number of interengaged conveying screw members and at least one group of interengaged unsymmetrical modular mixing members. The conveying screw members are installed for dismantling on the rotating shaft and secured on it by keys. Each of the modular mixing members is also installed for rotation and dismantling on the shaft and secured on it by keys. Each group of unsymmetrical modular mixing members comprises at least one modular mixing member having a left twist. The mentioned mixing member is installed downstream at least of one modular mixing member having a right twist. Each modular mixing member has a great number of unsymmetrical wings. Each wing has a front surface and a rear surface with a wing edge between them. The front surface has a smaller radius of curvature as compared with the rear surface. A modification of an unsymmetrical modular mixing member is also described. EFFECT: enhanced shear stress in material, improved dispersive mixing. 21 cl, 16 dwg