Description: These machines can be used for conveying material that is fed through one or more inlets: a rotor equipped with helicoidal elements (screws or paddles) and driven at low speed propels the material inside the conveyor structure.The rotor, formed by a pipe housing the helicoidal elements and equipped with shafts on the ends, is supported and guided by end supports that mount rolling-element bearings. The rotor is equipped with intermediate supports whenever material must be conveyed more than 8 – 10 metres.Effective triple packed gland seals prevent spillage of material from the trough ends.The conveyed material slides on the bottom of the trough and on the helicoidal propelling body, which may come in the shape of a full-bladed, ribbon or paddle screw.The structure generally comes with a “U” or “V” shape and cover, or tubular shape. The latter is more cost-efficient while the former two are easier to inspect.The standard size of the screws (rotor diameter) complies with the sizes outlined in the DIN 15261 standard. The flow rate may reach 500 m3/hour for larger-sized horizontal screws. The screw conveyors are usually used for short hauls (below 20 m) although they can sometimes be used for hauling material over 50 m or more.When specially adjusted, horizontal screw conveyors may also be used to extract material from hoppers or silos. Special screw conveyors may be required to perform certain functions that include mixing, humidification and cooling, while other functions may be satisfied case-by-case through custom-made design solutions.