Online aluminum degassing system is commonly used in the market. The online aluminum degassing unit has high degassing and refining effect, and the heating system can reduce the temperature loss of casting. However, the online degassing system has the disadvantage of large degassing space and high residual aluminum content. The inline degassing system is just the opposite of the online degassing system, which has the characteristics of no residual aluminum and small footprint. However, the disadvantage of the inline degassing system is that the temperature drop is large and the slagging is large, and its graphite rotor is easy to break. Vacuum degassing machine and ultrasonic degassing machine are not widely used, and their use effects are yet to be tested by the market.
Online Aluminum Degassing System
After aluminum alloy melting and refining, the influence of water intake position, adding time before and after refining agent, nitrogen flow rate of rotary degassing, rotational speed of graphite rotary rod, degassing time, diameter and height of graphite rotary rod on aluminum liquid density were measured and analyzed.
After degassing, the degassing effect is not consistent at different positions in the ladle, and the worst is near the turntable.
The results show that the nitrogen flow rate has a certain influence on the bubble generation position, and the large flow bubble diffuses further, but it causes the aluminum liquid tumbling more seriously, which will cause production safety hazards.
The rotating speed has a great influence on the degassing effect of aluminum liquid. High speed can ensure the gas diffusion more fully and ensure the aluminum liquid does not roll over.
The addition time of the refining agent has little effect on the degassing process, and can not reach the purpose of refining inside the liquid aluminum, so the surface scum can be treated. It is suggested that slag remover should be used to treat the surface aluminum slag. According to the refining agent specification, the refining agent temperature is 700 ~ 750 ℃, and the slag and degassing agent temperature is ≥ 680 ℃. The refining agent has high requirements on the aluminum liquid temperature, which is difficult to control on site.
The rotation speed and nitrogen flow rate should be used together to ensure the degassing effect and the aluminum liquid will not be oxidized due to rolling. The flow rate of 15L / min can meet the requirements at 400R / min.
In the degassing process, the rolling and splashing of molten aluminum have an effect on the degassing and oxidation of molten aluminum. After degassing, the surface aluminum slag and sample density can reflect the degassing efficiency.