The deep bed filter adopts a metal box structure with high performance heat insulation lining and refractory casting lining. The box is sealed by the upper heating cover, and the heating cover also preheats the filter. The box body is generally composed of two cavities, the inlet cavity is equipped with a filter layer, and the filter layer is supported by a grid. The filter bed is composed of many layers of alumina balls and gravel layers. The choice of filter material size and the distribution of different layers play a key role in optimizing the filtering effect and extending the life of the filter layer.
The pore size of the filter layer of the deep bed filter is 100 times larger than the size of the impurity particles to be filtered. If the filtration speed is 0.1~0.4cm/s, the interception and adhesion of impurity particles by the filter layer is maximized. In contrast to ceramic foam filter filtration, deep-bed filters are not affected by changes in the density of impurity particles.
In production practice, it is required that the liquid metal must completely fill the entire space of the filter layer, otherwise the filter efficiency of the filter will be reduced and the service life of the filter bed will also be affected. During use, the filter is heated and insulated by the upper and lower heating devices, which can maintain a longer service life of the filter, and the cast metal can reach more than 7000t. Therefore, the deep bed filter is suitable for the production of larger batches of alloys.
The deep bed filtration system is a high-precision filtration system recognized by the global aluminum melting and casting industry, which is suitable for the -precision filtration requirements of all alloy grades. The filtration method of the deep-bed filter is from top to bottom of the molten aluminum, through a filter layer composed of alumina balls and gravel to achieve efficient removal of impurities. The size of the filter bed and the filter area are designed according to the melt flow rate. It is widely used in industries that have strict requirements on the quality of aluminum alloy, such as high-purity aluminum, can material, double zero foil, printing plate base, and mirror panel.