The Ottevanger Roll Feeders guarantees an even supply to the hammer mill and is driven by a special 1.5 kW motor reducer which can be regulated by a frequency converter. It has an integral stone catcher for removal of heavy particles. Iron particles are extracted by an extra-strong permanent magnet with an automatic cleaning system. The items removed are collected in a tray. The feed roller, stone catcher, magnet and collection tray are assembled into a fully sealed feed unit. The special, multiple dosing screw can be used as an option for very fatty products and products with poor flow characteristics.