Molten aluminum degasser is a degassing and purification product. It uses the most advanced control technology, man-machine interface, and is controlled by PLC computer program. According to the alloy flow rate and purification degree, the purity of aluminum melt is ensured. In terms of technology, the single rotor degassing box adopts a new concept and is successfully developed and designed.
Some disadvantages of degassing in aluminum processing industry are solved, such as poor structure, low degassing rate, large gas consumption, large temperature drop, low monitoring level, and the long-term “short degassing” problem. Circuit “and” bubbling “. It has the advantages of high degassing rate, low operating cost, reliable operation and simple maintenance.
The lining of molten aluminum degassing unit has good thermal shock resistance, cold and hot shock resistance and low thermal expansion coefficient.
It maintains a stable appearance at operating temperatures and has excellent non wetting properties with aluminum. After flowing through the aluminum liquid, it will not stick to the aluminum and is easy to clean.
It has good liquid, non corrosive, and low surface chemical resistance to aluminum.
The on-line degassing equipment mainly deals with molten aluminum containing a certain amount of hydrogen and other residues (alkali metals, slag inclusions), which will be removed after being treated by degassing equipment.
The treatment principle of on-line degassing equipment is air flotation principle. The process gas (inert gas or mixture of inert gas and chlorine) is injected into the melt through the rotor and broken into uniformly dispersed micro bubbles, which rise to the surface of the melt.
Working Principle of Molten Aluminum Degasser
1. Hydrogen is absorbed by bubbles and eliminated;
2. Alkali metals are eliminated by chemical interaction with chlorine (forming chloride);
3. Inclusions are trapped by bubbles and then rise to the surface of melt to form slag.
Baking requirements and precautions for aluminum melting degasser:
1. Before baking, screw off the nuts of the ventilation holes around the box to facilitate the drainage of moisture from the insulation lining.
2. Before baking, take out the rotor of degassing box, and the filter box cannot be equipped with filter plate.
3. The aluminum outlet, aluminum inlet, outlet and rotor hole of the box are plugged with fiber blanket. The upper opening of the box is covered with a 20 mm thick fiber blanket, and the cover is covered.
4. Insert the thermocouple into the temperature measuring hole of the box cover to control the gas temperature in the furnace.
5. The normal control temperature of aluminum water in the box is about 750 ℃, and the temperature difference of gas conduction in the furnace is about 50 ℃. Therefore, the maximum control temperature of gas in the furnace is 800 ℃.
6. If the temperature controller has program control function, it can run automatically according to the baking curve, but it can also be controlled manually.
7. If the temperature controller has no program control function, it will adopt step-by-step manual control within the time interval. The maximum current of the power regulator shall not exceed the rated current.
8. When the maximum temperature is 800 ℃, the insulation is finished and the power is cut off. When the temperature is lower than 200 ℃, the cover can be opened for cooling or inspection. At the same time, tighten the exhaust nut.
9. Special attention: during the whole process, please do not open the cover or remove the rotor hole, drain hole and aluminum fiber blanket, so as to avoid cracks in the lining plate caused by rapid cooling impact.