The aluminum degassing purification equipment specially designed and manufactured by AdTech is used in the casting production line.
The hydrogen content and non-metallic inclusions of the molten aluminum alloy in the melting and casting workshop will seriously affect the quality of the castings. Usually during the condensation process, as the solubility of hydrogen decreases, it is too late for hydrogen to escape from the solution, and non-metallic inclusions are too late to float to the liquid surface before entering the crystallizer, which will cause plates and foils in the subsequent rolling process. The white spots and pinholes on the surface of the material increase, and the mechanical properties of the material decrease, which will eventually lead to a scrap of the product. Therefore, the aluminum alloy melt must be degassed and purified.
The aluminum degassing purification equipment is equipped with a graphite rotating shaft rotor that sprays inert gas, which is step-less speed regulation and normal operation. The graphite shaft is lifted by a hydraulic device outside the box and can rotate freely for 180, which is convenient for maintenance. The degassing chamber has reasonable slag removal holes and drains holes. The filter box is provided with a foam ceramic filter as a filter medium, and a discharge port is left under it.
The working principle of the degassing filter box is to use the inert gas that does not chemically react with the aluminum melt at the melting temperature, and is insoluble in the aluminum melt. It is sprayed into the aluminum melt through the high-speed rotating graphite shaft to form a large amount of continuous small bubbles. When the inert gas bubbles rise from the bottom of the melting chamber, because the hydrogen partial pressure in these bubbles is PH=0, the hydrogen in the melt will continue to diffuse to the bubbles until the partial pressure of hydrogen in the bubbles increases to the concentration of hydrogen in the melt. Balance is reached when a certain relationship is met. After the bubbles rise to the surface, the hydrogen in the bubbles escapes into the atmosphere.
In the process of bubble floating, when encountering non-metallic inclusions, the inclusions adhere to the surface of the bubble due to the effect of surface tension. These inclusions are removed as the bubbles rise. At the same time, the filter medium in the filter cavity will further mechanically block the inclusions. The impurity deposits are blocked in the filter medium, so that the aluminum liquid can be thoroughly purified.