Practice has proved that the foam ceramic filters for aluminium foundry is an effective tool for removing oxidized inclusions in the melt. General fiber filtration can only remove large impurities, while the ceramic foam filters for aluminium foundry can filter both large and small impurities.
After the smelting furnace, the degassing box and the aluminum melt filter box are connected through the launder, and then transferred to the template for casting. In this process, the flow channel is very long, and the molten aluminum will form slag and absorb air when flowing through the flow channel and the template, which will affect the quality of the molten aluminum. The aluminum purification system is to reduce the length of the launder as much as possible by integrating the degassing and filtering functions, so as to achieve the purpose of reducing the pollution of the aluminum liquid.
The molten aluminum enters the degassing chamber through the launder, and argon is introduced to start the degassing and refining operations. The flow of argon is slightly vibrated by the surface of the molten aluminum and will not roll violently. After degassing, the hydrogen content in the melt can be greatly reduced.
After degassing, the molten aluminum flows to the filter chamber. Under the action of hydrostatic pressure, it passes through the ceramic foam filter.
When the CFF filtering device is started, the liquid level difference before and after the melt filtering is about 50 mm. However, with the extension of the filtration time, the inclusions and pore walls on the surface of the filter plate increase, the filtration flow rate decreases, and the liquid level difference increases. By the end of casting, the amount of drop increased to 60-120 mm. The choice of filter plate depends on the flow of molten aluminum.
Secondly, the cleanliness of the melt, the content of inclusions, and the total output of the melt should be considered. When designing the filter device, the filter box should be selected according to the specifications of the selected filter plate, and the fall of the furnace mouth and the manifold should be considered. In addition, it should be considered that the installation and disassembly are very safe and convenient. After the casting is completed, the aluminum liquid in the filter box can be completely drained.