The rigid screw conveyors are the ideal solution for the transport of shell products on long distances. They can have variable capacity and length, they can be integrated on already existing systems to further improve their efficiency. They are endowed with an helicoid, which rotating on its axle, practices an axial thrust component on the materials contained in the canal. The motorization of these systems can be decided and applied according to the exigencies of the moment and to the typology of production.