A scrap melting system and method includes a vessel that is configured to retain molten metal and a raised surface about the level of molten metal in the vessel. Solid metal is placed on the raised surface and molten metal from the vessel is moved upward from the vessel and across the raised surface to melt at least some of the solid metal. The molten metal is preferably raised from the vessel to the raised surface by a molten metal pumping device or system. The molten metal moves from the raised surface and into a vessel or launder.

A scrap melting system and method includes a vessel that is configured to retain molten metal and a raised surface about the level of molten metal in the vessel. Solid metal is placed on the raised surface and molten metal from the vessel is moved upward from the vessel and across the raised surface to melt at least some of the solid metal. The molten metal is preferably raised from the vessel to the raised surface by a molten metal pumping device or system. The molten metal moves from the raised surface and into a vessel or launder.

The present invention is directed to a molten metal pump comprising an elongated pumping chamber tube with a base end and an open top end. A shaft extends into the tube and rotates an impeller therein, the impeller rotates proximate the base end. The tube has a diameter at least 1.1 times the diameter of the impeller. The pumping chamber tube preferably has a length at least three times the height of the impeller. The base end includes an inlet and the top end includes a tangential outlet. Rotation of the impeller draws molten metal into the pumping chamber and creates a rotating equilibrium vortex that rises up the walls of the pumping chamber. The rotating vortex adjacent the top end exists the device via the tangential outlet.

A molten metal rotor receives and retains an end of a molten metal rotor shaft. The rotor shaft has one or more projections at the end received in the rotor. The rotor has an inner cavity, a top surface with an opening leading to the inner cavity, and at least one abutment. The opening includes one or more portions for allowing each projection to pass through the opening and into the inner cavity. The rotor and/or shaft are then rotated so at least one of the outwardly-extending projections is under the top surface of the rotor and is against an abutment. A molten metal pump, rotary degasser scrap melter or other device used in molten metal may utilize a rotor/shaft combination as disclosed herein.

An annular linear induction electromagnetic pump having axial guide vanes is provided. m axial guide vanes are uniformly arranged in a flow channel of the electromagnetic pump in a circumferential direction, and a magnitude of m is equal to a number of external stators. A length of each of the guide vanes is precisely determined by a parameter P, and the value of the parameter P is calculated together by the number of the external stators, a central radius of the flow channel, a magnetic Reynolds number, a wave number of a traveling magnetic field and the mean fluid velocity. The axial guide vanes can significantly mitigate the impact on the flow field stability caused by uneven circumferential disturbances of the magnetic field and flow field, thereby achieving a flow stabilization effect with less hydraulic losses and greatly improving the flow stability in operation under off-design conditions.

The present invention provides an annular linear induction electromagnetic pump having axial guide vanes, wherein m axial guide vanes are uniformly arranged in a flow channel of the electromagnetic pump in a circumferential direction, a magnitude of m is equal to a number of external stators, and a length of each of the guide vanes is determined together by the number of the external stators, a central radius of the flow channel, a magnetic Reynolds number, and a wave number of a traveling magnetic field. The axial guide vanes can significantly mitigate the impact on the flow field stability caused by uneven circumferential disturbances of the magnetic field and flow field, thereby achieving a flow stabilization effect and greatly improving the flow stability in operation under off-design conditions.

Disclosed is a centrifugal molten metal pump assembly and associated system for controlled delivery of molten metal to molds. The pump assembly comprises a shaft, an impeller coupled to the shaft, a controller to control a rotational speed of the impeller according to a programmable fill profile while delivering the molten metal to the mold. In some embodiments, the pump assembly further comprises a throttle to manipulate a flow rate or pressure of the molten metal relative to a rotational speed of the impeller. The associated system comprises a melting furnace and one or more holding furnaces, each holding furnace including at least one pump assembly therein. Each holding furnace may be of an open configuration to allow for uninterrupted flow of the molten metal from the melting furnace. The system may provide controlled delivery of the molten metal to the mold at a desired flow rate or pressure.

A molten metal pump includes an impeller, a pump base housing at least partially enclosing the impeller, a shaft connected to the impeller, a motor connected to the shaft, a motor mount plate for supporting the motor; and a post for connecting the motor mount plate to the pump base housing. The molten metal pump can include a connector that connects the post to the motor mount plate. The molten metal pump can include a socket for connecting the shaft to the motor. The shaft can comprise an assembly including an elongated metal rod having a first end and a second end and a metal non-circular drive member attached at the second end of the elongated metal rod. The impeller can include a cap member having a plurality of generally polygonally shaped inlet openings communicating with internal passages of the impeller, each inlet opening having an inner wall and an outer wall, the outer wall being longer than the inner wall, each inlet opening also including a leading wall and a trailing wall, the leading wall and the trailing wall each interconnecting the inner wall and the outer wall and each being inclined such that an uppermost edge of each wall precedes a lowermost edge of each wall in a first rotational direction.

A vertical member, which is preferably a support post used in a molten metal pump, includes a ceramic tube and tensioning structures to add a compressive load to the tube along its longitudinal axis. This makes the tube less prone to breakage. A device, such as a pump, used in a molten metal bath includes one or more of such vertical members.

A vertical member, which is preferably a support post used in a molten metal pump, includes a ceramic tube and tensioning structures to add a compressive load to the tube along its longitudinal axis. This makes the tube less prone to breakage. A device, such as a pump, used in a molten metal bath includes one or more of such vertical members.