CRITICAL FREQUENCY OF ROTATION IN THE SPIRAL SCREW DEVICE

The rotation of a vertically placed wire spiral is considered, the surface of which is formed by the displacement of the radius perpendicular to the axis of the helix, and also the forces acting on the particle of the material being moved. At the same time, a frictional force acts on the particle, pressed against the inner surface of the casing, under the action of inertial force. Having designed all the forces acting on the particle, we have obtained the equilibrium equations. As a result, the values of the angle between the normal reaction of the helical surface and the axis perpendicular to the helical line were obtained characterizing the geometric characteristics of the helix, the cylindrical casing, and the particle size of the material in the device. The speed of the axial movement of the material particle, the smallest angular velocity of rotation of the spiral and the corresponding rotation frequency, at which the axial movement of the material particle becomes impossible, were determined. The critical rotational speed of the spiral screw is shown for vertical material movement, which means that the vertical device for moving the material with a spiral-helical working member is high-speed.