Impact of the Blade Profile on the Production of the Screw Press

Screw presses are widely used in the production of clay bricks by a soft-mud process. The main drawback of screw presses is a torque transfer by the screw blade to the shaped mass so that the mass moves in a spiral. This significantly reduces the performance of screw presses. The work considered the possibility of increasing the performance of screw presses by increasing the friction force of the shaped mass as it moves along the internal surface of the tube. This is achieved by increasing the force of the normal pressure of the shaped mass on the internal surface of the tube by modifying the geometry of the screw blade so as generatrics are not oriented normally towards the screw axis, but inclined opposite to the direction of motion of the shaped mass from the axis of the screw to the periphery. The results of the study show that the performance of the screw press with a blade having an inclination from the axis of the screw to the periphery of 10–30% higher, than a press with a generatric of the blade normal towards the axis of the screw shaft, for the supply of plastic clay by increasing the forward component of the shaped mass movement in the direction of the longitudinal axis of the screw. Analysis of the results shows that the rational value of the angle of inclination for the generatric of the blade depends on the properties of the moulded mass and this value is 10–20°.