The screw consists of several blades in helix shapes that are welded to a pipe or a shaft which move the material. Screw conveyors are also known as spiral conveyors, helix conveyors. Their modular design makes them easy to install. They are compact in size, reliable and flexible in operation. Screw conveyors are an efficient way to move semi-solid materials, including food waste, wood chips, aggregates, boiler ash, municipal solid waste and many others.