The correct selection of the type of filter box and the specifications of the foam filter plate can obtain satisfactory filtering results. You can choose the right filter box according to the quality requirements of the finished castings, the flow, total filtration, the cleanliness of the aluminum liquid. The purification methods for metal foundry is used in most metallurgical engineering.
Purification Methods for Metal Foundry
After the smelting furnace, the degassing box and filter box are connected through the launder, and then transferred to the mold plate for casting. In this process, the runner is long, and the aluminum liquid will form slag and get air when passing through the runner and die plate, which will affect the quality of the aluminum liquid. The aluminum purification system is to reduce the length of the flow tank as much as possible by integrating the degassing and filtering functions, so as to achieve the purpose of reducing the contamination of the aluminum liquid.
The aluminum liquid enters the degassing chamber through the launder, and argon gas is introduced to start the degassing and refining operation. The flow rate of argon gas is subject to the slight vibration of the aluminum liquid surface and not violent tumbling. After degassing, the hydrogen content of the melt can be greatly reduced.
After degassing, the aluminum liquid flows to the filter chamber. Under the action of hydrostatic pressure, it passes through the filter plate. After finishing the first filtration, molten aluminum enters the flow cell through the water outlet.
In order to avoid molten aluminum tumbling and slagging under the condition of large drop, the method of lap of flow groove was adopted. Perforating the guide tube at the end of the launder, so that the aluminum liquid flows into the launder from the leaky pipe, and the outlet of the pipeline is buried under the liquid surface of the launder, so as to avoid oxidation and slag formation.
Lay a 60ppi filter plate from the flow tank to the 600mm of the crystallizer. So that the aluminum liquid enters the crystallizer through the filter plate under the action of gravity, and complete the second filtration. Two-stage filtration can remove impurities larger than 10μm and purify aluminum liquid. After degassing and filtering treatment, a cast rod with a high degree of purification can be obtained.
Features of Molten Aluminum Filter Boxes
- Significant filtering effect. Filter boxes can meet the requirements of ordinary products, even can meet aluminum alloy cans, aviation alloys and other demanding occasions.
- The filtering method is simple. Foam ceramic filter plates have been standardized and serialized. According to aluminum water quality requirements, flow rate and other requirements, equips with different hole size (20ppi-60ppi) filter plates combination methods, filter box can achieve different filtration effects.
- Economic savings. The filter plate has high strength, resistance to aluminum water washout, and good thermal shock performance, and the filter plate has a long life. The heating cover can ensure that the same filter plate is reused more than 6 times in the filtrate, reducing the cost of consumables. The filter box lining is similar to the degassing box, not infiltrated with aluminum, good thermal insulation, resistance to cold and hot shocks, and long life.
- Simple installation and maintenance. The lining of the pre-fired shaped filter box is easy to replace, minimizing production downtime.