Screw conveyors have been a popular material handling mechanism throughout history.
They are used in many bulk handling industries. Although inclined screw conveyors can function as an Archimedes screw, many bulk systems have chutes guiding material flow into such screws. Screw conveyors in modern industry are often used horizontally or at a slight incline as an efficient way to move semi-solid materials, including food waste, wood chips, aggregates, animal feed, boiler ash, meat and bone meal, municipal solid waste, and many others.
Screw conveyors can have a greater pitch spacing, resulting in a higher capacity without an increase in rotation speed. They usually consist of a trough containing either a spiral coiled around a shaft, driven at one end and held at the other, or a Shaftless Spiral, driven at one end and free at the other.
Screw Conveyors can be operated with the flow of material inclined upward. When space allows, this is a very economical method of elevating and conveying. It is important to understand, however, that as the angle of inclination increases, the allowable capacity of a given unit rapidly decreases.
