The transmission system drives the graphite rotor

Update:15-06-2019
Summary:

It consists of two parts: the rotor rod and the nozzle. […]

It consists of two parts: the rotor rod and the nozzle. The transmission system drives the graphite rotor to rotate, and the argon or nitrogen gas is blown into the aluminum melt through the rotor rod and the nozzle. The high-speed rotating graphite rotor breaks up the argon or nitrogen entering the aluminum melt to form a lot of small bubbles, which are dispersed in the molten metal, and the rotating rotor also promotes the diffusion of hydrogen and inclusions in the aluminum melt, so that In contact with the bubble, the bubble in the melt relies on the gas partial pressure difference and the surface adsorption principle, absorbs the hydrogen in the melt, adsorbs the oxidized slag, and is taken out of the melt surface as the bubble rises, so that the melt is purified.

The speed of the graphite rotor can be adjusted steplessly by the speed control of the frequency converter, up to 700 r/min. The graphite rotor has a specification of Φ70mm~250mm, and the impeller specification is Φ85mm~350mm. The high-purity anti-oxidation graphite rotor has the characteristics of high strength, high temperature resistance and aluminum flow corrosion resistance. During the process of purifying and degassing, the surface of the aluminum alloy liquid in the tank is protected by nitrogen gas, so that the part of the graphite rotor exposed to the aluminum alloy liquid is in an inert gas, preventing the high temperature oxidation of the rotor and prolonging the service life of the rotor. The shape of the impeller is streamlined, which can reduce the resistance during rotation, and the frictional force generated between the impeller and the aluminum alloy liquid is relatively small. Thereby, the outgassing rate is above 50%, the smelting time is shortened, and the production cost is reduced.

Graphite rotor

Use graphite rotor operation tips:

1. Preheating before use: Before immersing in aluminum liquid, the graphite rotor is preheated for about 5min~10min above the liquid surface to avoid the influence of quenching on the material; the rotor must be filled with gas before immersing in the liquid; The air supply can be stopped afterwards to prevent clogging of the air nozzle of the rotor nozzle.

2. Isolation of air: Nitrogen or argon is introduced into the chamber of the purification tank to ensure positive pressure inside the chamber and to isolate external air to prevent oxidation of the graphite rotor.

3. Rotor immersion depth: The reasonable depth of the graphite rotor immersed in the aluminum melt, so that the reinforced sleeve exposes about 80mm of the aluminum liquid surface and immersed to about 60mm below the liquid level, which can effectively increase the rotor oxidation loss and the time of erosion wear.

4. The transmission system is stable: the graphite rotor and the transmission system are connected by connecting rods (tubes). The connecting rods are deformed under high temperature for a long time, or the relevant parts of the transmission equipment are loose, which will affect the centering and operation of the rotor. The smoothness of the graphite rotor is easily broken or bumped.

5, argon or nitrogen should be pure: if the pipeline, joints and other components leak gas, the argon or nitrogen gas flowing into the aluminum melt is not pure, which will cause severe oxidation of the upper part of the rotor, and even the lower rotor holes of several rotors It is oxidized, which will greatly shorten the service life of the rotor. Recarburizing agent for refining steel for refining steel (People's Republic of China ferrous metallurgical industry standard, YB/T 192-2001 steelmaking recarburizer) and cast iron recarburizer, and other additives are also useful to recarburizer For example, brake pads are used as additives for friction materials. The recarburizer belongs to the additional steelmaking and ironmaking carbon-increasing raw materials. High quality carbonizers are essential additives for the production of high quality steel.

There are many kinds of raw materials for the recarburizer, and the production process is also different. It is not said on the market that graphite powder is pressed and formed. This production method requires the addition of too much binder to form, and the carbon content generally does not meet the requirements of high-quality recarburizer.

Since the pressed graphite powder is a solid block and has no porous structure, the absorption rate and the absorption rate are inferior to those of calcination and calcination. High-quality recarburizers generally refer to graphitized recarburizers. Under high temperature conditions, the arrangement of carbon atoms is in the microscopic form of graphite, so it is called graphitization. Graphitization can reduce the content of magazines in the recarburizer, increase the carbon content of the recarburizer, and reduce the sulfur content. The recarburizing agent is used in casting, which can greatly increase the amount of scrap steel, reduce the amount of pig iron or use no pig iron. Most of the recarburizers are suitable for electric furnace smelting, and there are also a small number of recarburizers with a particularly fast absorption rate for the cupola. In the feeding mode of electric furnace smelting, the recarburizing agent should be placed together with the charging materials such as scrap steel, and the addition of small doses can be added to the surface of the molten iron. However, it is necessary to avoid feeding large quantities into the molten iron to prevent excessive oxidation and the carbonization effect is not obvious and the carbon content of the casting is insufficient. The amount of the recarburizer added is determined according to the ratio of other raw materials and the carbon content. Different types of cast iron, choose different types of recarburizers according to your needs. The characteristics of the recarburizer itself select pure carbon-containing graphitized materials to reduce excessive impurities in the pig iron. The selection of the recarburizer can reduce the production cost of the casting.