The common methods of metal degassing rotary refining are degassing refining and powder spraying refining. The principle is to pass inert gas or refining agent to the bottom of the furnace.
The refining agent is very light, and the inert gas or refining agent starts to rise from the bottom of the furnace, and the hydrogen and scum in the aluminum liquid are taken away during the ascending process, so as to achieve the purpose of purifying the aluminum liquid.
The degassing unit used in degassing refining drives the flange plate through the motor, and the flange plate is connected to the graphite rotor to rotate.
The refining effect of rotating powder spraying is better, but it is easy to block the graphite rotor. In production, dry inert gas or high-purity nitrogen is often used for refining. The gas is connected to the flange, the flange starts to rotate under the drive of the motor, the graphite rotor rotates with the flange, the speed is 400 ~ 600 r/min, and the flow of inert gas (argon) is controlled at 15-25 L /min, nitrogen is 20~40 L/min, pressure is (0.4±0.1) MPa.
Operation Process of Metal Rotating Degassing Refining Equipment
First open the gas valve, then slowly lower the deaerator until the distance between the graphite rotor of the deaerator and the bottom of the ladle is 100-150 mm, and finally turn on the motor to start degassing and refining.
The refining time is 10-20 minutes. In order to avoid the vortex caused by the high-speed rotation of the graphite rotor, a baffle plate is placed on one or both sides of the graphite rotor to reduce the turbulence of the molten aluminum during the rotation. When the graphite rotor is degassing, it ensures that the bubbles are small, the dispersion is high, and the effect is good, so that the degassing effect can be ensured, and the bubbles will not break the surface oxide film and cause boiling, and avoid secondary inhalation.
After the degassing is completed, turn off the motor, lift the graphite rotor away from the liquid surface, and then close the gas valve.