The molten aluminum degassing device is the key equipment for the purification of aluminum melt. In a great sense, it is a step in the improvement of the quality of aluminum. At present, on the road to high-end materials, there are usually several basic directions, namely
Larger and more able to bear the load;
Smaller and more precise
Purer and cleaner;
Better than performance;
The molten aluminum degassing device is an important equipment that allows the aluminum alloy material to flow in the above 4 directions.
Although the degassing device is called a degassing device, it actually has two conventional functions of degassing and slagging, and it also has the function of removing alkali after changing the composition of the refined material.
Let me talk about regular functions first.
Degassing is similar to the principle of degassing in the furnace, under normal circumstances, the partial pressure difference between the inside and outside of the dispersed bubble is used to induce the H in the melt into the bubble and take it out of the melt. These bubbles are usually N2 or Ar gas. Using the same refining material (such as N2, Ar, Cl2, CCl4, flux, etc.), the effect of the degassing device is significantly better than the refining effect in the furnace because the organization of the two is different.
Furnaces generally contain dozens of tons of aluminum, and the diffusion effect of bubbles during refining is difficult to take care of the corners and corners; the degassing device is a checkpoint on the path that the melt must pass, and all the melt that passes through must be processed.
There is also a degassing device installed on the launder (called ACD). Several rotors are distributed along the flow direction of the melt. The refined substance diffuses into the melt through the rotor and intercepts the H layers in the melt and degass. The effect is said to be ok, but in general, the box-type degassing through the inner chamber design has more control over the flow path of the melt, and also avoids the adverse effects of the drop in molten aluminum temperature during the casting start-up stage, and the degassing effect is more stable reliable.
The principle of slagging and degassing in the furnace is the same. Since the dispersion effect is better, the effect of adsorption and slag removal will be better. But the degassing device is not the main force used to remove slag. If the melt in the furnace is not processed properly, the load on the degassing box will increase, and the slag removal efficiency will increase, but the overall quality of the melt will decrease and the rotor will wear out. Speeding up is not conducive to quality and efficiency.