The effect of machine inclination

1 The volume of material that can be carried forward in the pitch space decreases with the change in geometry to determine the maximum level of the pocket of material that can be moved. 

2 Material spills over the shaft back into the previous pitch space due to the lowering of the effective angle of the central region of the flight from below the angle of slip. 

Apart from the heavy torque demands, the main operating drawbacks to this form of elevating are that the full screw resists feed at the inlet, so the machine will only work 

Another crude form of screw elevator is the so-called flexible screw elevators. The very limited flexibility these machines possess is permitted by the use of a plastic tubular casing and continuous screw flight that does not have a centre shaft. These units mainly have small diameter coreless screws, i.e. without centre shafts, running at relatively high speeds. 

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