The working principle of the graphite rotor and extend its service life


The working principle of the graphite rotor is: the graphite rotor breaks the nitrogen (or argon) blown into the aluminum melt into a large number of dispersed bubbles and disperses them in the liquid metal. According to the principle of gas differential pressure and surface adsorption, the bubble absorbs the hydrogen in the melt, adsorbs the oxide slag, and brings out the melt surface with the rise of the bubble, so that the melt is purified. Due to the fine dispersion of the bubbles, they are evenly mixed with the rotating melt and then rotated, slowly floating up in a spiral. The long contact time with the melt does not form a continuous straight upward gas flow, thereby removing harmful hydrogen from the aluminum melt and significantly improving the purification effect.

From an operational point of view, how to extend the service life of the graphite rotor is detailed!

1. Preheating before use: the graphite rotor is preheated for 5min~10min at about 100mm above the liquid level, and then immersed in the molten aluminum to avoid the influence of quenching on the material; Before immersion in liquid, the rotor must be filled with gas; The air supply can only be stopped after the rotor level is raised to prevent clogging of the pores of the rotor nozzle.

2. Isolation air: Nitrogen or argon is introduced into the purification box to ensure positive pressure in the box, isolate the outside air, and prevent the graphite rotor from oxidizing.

3. Rotor immersion depth: The reasonable depth at which the graphite rotor is immersed in the aluminum melt makes the reinforcing sleeve exposed to about 80mm under the aluminum liquid surface and about 60mm under the liquid surface, which can effectively increase the oxidation loss and erosion of the rotor.




  4. 稳定的传动系统:石墨转子通过连杆(管)与传动系统连接。连杆在高温作用下长时间变形,或传动设备相关部件松动,会影响转子的中性和运行稳定性,容易折断或撞击石墨转子。氩气或氮气应为纯净的:如果管道、接头等部件的泄漏导致不纯的氩气或氮气进入铝熔体,转子上部会严重氧化,甚至下部的几个转子喷气孔也会被氧化,这将大大缩短转子的使用寿命。