An other feeder system is the hydraulic rotor system. It starts witout the hydraulic system. After a 20-30 s delay the hydraulic system starts and the rotor arms digs into the stored material and transport it through the opening in the silo floor. The Rotor is used mainly in wood handling.
The system features an electromechanical driven rotor with hydraulic-actuated feeder arms. The systems are designed for round silos up to 7 500 mm diameter.