Rotary blowing rotor produced with combination of plumbago and ceramic

Abstract

A rotor of rotary impeller of compositing graphite and ceramic belongs to the field of the purification treatment of aluminum melt. The invention comprises a graphite nozzle and a graphite-ceramic composite nozzle. The graphite nozzle is connected with the graphite-ceramic composite nozzle. The graphite-ceramic composite nozzle comprises two parts, and the internal part is a graphite tube which is covered with a ceramic bushing. The internal part of the graphite-ceramic composite nozzle is a through hole which is a gas channel. The graphite nozzle is equipped with a jet orifice for gas ejection. The ceramic material is silicon nitride bonded silicon carbide material, and the component and the weight percent are: 45 to 70 percent of silicon nitride and 30 to 55 percent of silicon powder. The ceramic material of the invention has the advantages of the good high temperature oxidation resistance, the good thermal shock resistance, the strong slag corrosion resistance, the high strength and the wear resistant, preventing from the erosion and oxidation of the graphite tube from aluminum liquid and air, thereby achieving the longer service life of the rotor of rotary impeller of compositing graphite and ceramic than that of the original rotor of rotary impeller with full graphite material.

Description

technical field [0001] The invention relates to a rotary blowing rotor in the technical field of aluminum melt purification treatment, in particular to a rotary blowing rotor made of composite graphite and ceramics. Background technique [0002] Aluminum and aluminum alloys are easy to absorb hydrogen from the air during the smelting process, especially in the furnace gas with water vapor or reducing atmosphere, the ingot tends to form pores and looseness during crystallization. Therefore, the hydrogen content in aluminum and aluminum alloy melts should be reduced as much as possible. Rotary injection technology is currently one of the most widely used degassing methods. It mainly blows the inert gas into the melt through the rotor, and the high-speed rotating rotor crushes the bubbles to control the size and distribution of the bubbles, while the hydrogen in the melt is absorbed into the inert bubbles and floats together with the bubbles Discharge to the surface of alumin...

AI Technical Summary

Problems solved by technology

At present, graphite is mostly used as the material of the rotary blowing rotor. The problem in industrial application is that the service life is short, and it is easy to wear and peel off at the place in contact with the air and slag layer, and the phenomenon of "necking" occurs, that is, the rotor's The diameter becomes smaller and smaller at the place of wear and peeling until it breaks and is scrapped

[0003] After searching the literature of the prior art, it was found that Yang Changhe of Dalian University of Technology and others published "Research on Graphite Rotor Coatings for Purification of Aluminum Melts" on pages 7-9 of the second issue of "Special Casting and Nonferrous Alloys" in 1999, And "The Damage Mechanism of Graphite Rotor and Measures to Prolong Its Service Life" published in "Light Alloy Processing Technology" No. 1, 1998, pp. 4-7. The damage mechanism in the process of hydrogen removal and purification of graphite is described, and a method of improving the life of the rotary jet rotor by using the coating protection method is proposed. However, although the coating can effectively prevent the high-temperature oxidation of the graphite rotor and improve its wear resistance, the Due to the different thermal expansion coefficients of the coating and the graphite substrate, the rotary blowing rotor is easy to peel off during use and must be repaired regularly, which increases the production cost and affects the production efficiency, and the peeled coating also causes damage to the aluminum melt. pollution

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