Molten metal includes a high content of oxide and/or nitride debris, which has a negative effect on the solidification of certain alloys. The molten or liquefied form of aluminum also attracts the formation and absorption of hydrogen in molten aluminum. Hydrogen precipitates in the form of pores during the solidification of the aluminum alloy, and is not conducive to the mechanical properties of the solid alloy. Molten aluminium degassing is an effective method to reduce the porosity caused by hydrogen.
One of the molten aluminium degassing involves introducing a mixture of an inert gas (such as argon or nitrogen) and a reactive gas (such as chlorine) into the molten aluminum to collect hydrogen and wet solid impurities. The gas mixture bubbles up to the surface along with hydrogen and oxide impurities.
Molten aluminium may also require flux degassing. Flux degassing is a process of introducing powder or granular salt mixtures such as chloride and/or fluoride into molten aluminum via a carrier gas such as nitrogen or argon. Salt flux can be introduced by rotating degassing equipment. An exemplary rotating device includes a central hollow shaft attached to a rotor that is inserted into the molten aluminum pool and rotated so that the salt flux travels along the hollow shaft and is dispersed in the molten aluminum through orifices in the rotor.
There is still a need to provide an apparatus and method to effectively and safely handle the injection of a predetermined amount of degassing flux into molten metal.
The flux injector device includes a pressurized tank adapted to store and supply flux under pressure. A feed mechanism for discharging a predetermined amount of flux to the outlet of the pressurized tank and a controller for monitoring and operating the equipment. The feed mechanism includes a housing having an inner wall that defines a cavity with an inlet and an outlet. The feed wheel is positioned in the cavity and is operable to receive a predetermined amount of flux from the inlet, translate the flux in the cavity, and discharge the predetermined amount of flux through the outlet of the pressurized tank.
