During the production and operation of the melting furnace, it is constantly eroded and scoured by flame, waste gas and glass liquid, which will cause serious damage to some parts in more than five years, threatening the normal production and the service life of the kiln body. Under the condition that the glass water is put in, the production is not stopped, and the furnace is kept running, when the age of the furnace reaches more than eight years, a certain part should be repaired, which is the "hot repair" of the furnace. Generally, the parts that are often hot repaired are the pool wall bricks, the regenerator checker bricks, the small furnace sill and the slope sill, the nozzle brick, the large sill or the regenerator sill with dissolution holes, and the replacement of the bubbler.
The meaning of hot repair:
The hot repair of the furnace is necessary to ensure the normal operation of the furnace and prolong the life of the furnace. The kiln is the main thermal equipment for glass production. Daily maintenance alone cannot solve all problems. Hot repair is to maintain the kiln so that it can better serve the production. Seriously burned parts are basically repaired to their original structural state after hot repair to meet the requirements of the process, maintain normal production, and prolong the kiln age; after hot repair, the heat dissipation of the severely burned parts can be reduced, saving energy and reducing consumption; for some It has been proved by practice that the parts that are inconsistent with the production conditions can be improved, supplemented or transformed by hot repair, so as to achieve the purpose of increasing production; hot repair is essential to ensure the safe operation of the furnace, avoid personal and equipment accidents, and improve economic benefits. strong measures.
Selection of refractory materials for hot repair:
The refractory material used for hot repair should be the same material as the original design, or the material that will not produce chemical reaction with the contacting masonry, and will not cause low temperature eutectic material. Fill according to the degree of damage to the corroded part, and then immediately brush with hot repair mud. At present, there are many varieties of refractory materials in my country, and various sintering materials, electrofusion materials, ramming materials and other varieties are complete, which creates conditions for hot repair.
At present, there is a new hot repair welding process called ceramic welding technology. In this process, a mixture of dry refractory powder and ultra-fine metal powder is sprayed onto the high temperature surface of the furnace refractory with a stream of oxygen. The metal powder in contact with the hot surface is quickly ignited and burned, releasing a large amount of heat energy, so that the surface temperature of the furnace refractory material is as high as 2000 ℃ or more, causing the mixed powder of the refractory material to melt quickly and tightly bond with the refractory material matrix to be repaired. At the same time, the molten material fills the small holes, connecting surfaces, gaps, etc. on the refractory bricks and restores them to the original good state.
The thermal spraying equipment consists of a powder mixer, a material conveying system and a control device that can adjust different spraying parameters. If the interior of the furnace needs to be repaired, a water-cooled spray gun that can penetrate deep to the left and right should be configured.
The key to thermal repair using ceramic welding technology is to form a material that is compatible and matched with the base material. The earliest welding material used is siliceous gunning material. The chemical composition of siliceous gunning material is generally (mass fraction): SiO2 95%, Al2O3 2.5%, CaO 2%, Fe2O3 0.5%. It is especially suitable for the siliceous dome of the melting furnace, such as the opening junction of the dome and the front face wall, and the eroded part of the flame scour. The repair process is not affected by the atmosphere in the kiln, and the thermal shock resistance and corrosion resistance of the welding layer can reach the original level.
