The invention features a molten metal flow powered device including a housing, a rotor rotatably supported by the housing, the rotor being configured and arranged to be powered by a stream of molten metal discharged from a pump, and a gas transfer conduit having an upper end adapted to engage a gas source and a lower end supported by the housing from which gas is fed to the rotor. The invention also features a pumping and degassing system that includes the pump and a source of pressurized gas. The system can also include a machine for directing flux into the pressurized gas, for passage along the gas transfer conduit to the rotor.