The double rotor degassing device blows out refined gas through the rotor, and generates tiny bubbles with the help of rotating nozzles. The rotating nozzle is made of graphite, the nozzle structure design takes into account the uniform ejection of bubbles. The rotating impeller is also used to break the bubbles, increase the contact area and contact time between the bubbles and the aluminum melt, and improve the effect of purifying the aluminum melt.
Due to the high viscosity of aluminum alloy melt, if the diameter of the vent hole is too large, it is easy to stick aluminum and block the pore. According to the gas flow and the pressure of the molten metal in the degassing box, the diameter of the rotor pores can be calculated to ensure the purification treatment effect. The degassing box is equipped with a heater, which is used to preheat the container before injecting the aluminum melt, and can maintain or increase the melt temperature according to the characteristics of the cast alloy.
On-line double rotor degassing device is mainly to ensure that the three requirements of degassing, alkali metal removal and slag removal are met during the casting of molten aluminum.
(1) The hydrogen is removed by dissolving and adsorbing it into the bubbles. The high-speed rotating nozzle breaks the large bubbles with large volume and fast floating speed into countless small bubbles, which increases the surface area of the refined gas more than ten times or even Tens of times, these small refining bubbles are evenly dispersed and floated slowly in the molten aluminum.
(2) The alkaline metal reacts with chlorine to form a chloride salt to remove the alkaline metal.
(3) The slag inclusions are captured by the bubbles, and the larger slag inclusions collide with the bubbles to be captured. Smaller slag inclusions are captured by the radial cross-section of the bubbles, and then the slag inclusions rise to the surface with the bubbles to form scum, thereby obtaining a better purification and refining effect of the molten aluminum.