A screw conveyor is used within bulk handling installations for the controlled transport of bulk materials and bulk solids. The principle is based on the Archimedes screw, where a rotating screw moves the product through a tube or trough. Screw conveyors are applied for horizontal transport, inclined transport and vertical transport.

Characteristics of screw conveyors:

Multiple inlet and outlet points possible
Execution in tube or trough
Suitable for controlled transport over short to medium distances
Possibility for accurate dosing with an integrated dosing screw

Functions of screw conveyors

A screw conveyor can fulfil several functions within a process line.

Transport: horizontal, inclined or vertical
Dosing of bulk material
Mixing of product streams
Conditioning of product by cooling or heating

Required Power

The power depends on the capacity, the length and the friction of the product. For a horizontal screw conveyor handling granular products such as grain, flour and animal feed, the power is calculated as follows:
Power (kW) = Capacity (tonnes/hour) x Length (metres) x 0.007
As an example: a screw of 5 metres long with a capacity of 50 tonnes/hour requires approximately 5 x 50 x 0.007 = 1.75 kW of drive power.
For ores and crystalline products such as salt and sugar, the factor 0.007 is two to three times higher. For an accurate calculation and for inclined screw conveyors, use the calculation program from Jansen&Heuning.