Durable, easy-to-maintain screw conveyors are used for dust-free, horizontal, ascending and vertical transportation of fine-grained and floury materials in the field of conveyor technology. The properties of the screw conveyor/screw conveyor are adapted to the nature of the materials to be transported (coarse-grained, temperature-loaded, abrasive or poorly flowing materials). Screw conveyors offer the option of multiple inlets and outlets. In addition to transporting bulk materials, various screw conveyor designs can also be used for emptying, dosing, loading, screening, mixing or cooling.