Gunning material is an important refractory material. The use of gunning material is generally divided into wet gunning, semi-dry gunning flame gunning. The following is a detailed description of the use of gunning material: ramming material
1. Wet gunning is a method in which refractory aggregates, binders, additives water are mixed to form a slurry with a certain consistency, then the slurry is sprayed onto the gunning surface with compressed air through a gunning machine. Its characteristics are simple operation, high adhesion rate rapid sintering. However, due to the large water content finer grain size, the shrinkage is also greater. At the same time, because the gunning layer is thinner, the durability is very good.
2. Semi-dry gunning is a construction method in which refractory aggregates, binders, additives, etc. are mixed with water through the water ring holes at the end of the spray gun, compressed air is sprayed onto the gunning surface. The water consumption can be adjusted at any time according to the gunning situation, generally fluctuates in the range of ~14%.
Its characteristics are that the gunning layer has high bulk density small shrinkage, a thicker gunning layer can be obtained. It has better durability, but the rebound amount is higher than that of the wet method, the dust is slightly more.
3. Flame gunning is to use compressed oxygen to transport the mixture of refractory aggregate, flux heating agent to the nozzle, mix burn with high calorific value fuel, instantly heat the surface of refractory aggregate particles to a molten semi-molten state, then Repair method of spray adhesion on the furnace lining.
Its characteristics are that the gunning layer has a dense structure, high strength, strong erosion resistance, erosion resistance, solidity durability. But the flame gunning device is expensive, the technology is complicated, the construction consumes a lot of energy.
Refractory materials used in special occasions include high-temperature oxide materials, such as aluminum oxide, lanthanum oxide, cymbal oxide, calcium oxide zirconium oxide, etc., gunning materials for refractory compounds, such as carbides, nitrides, borides, silicides sulfides, etc., high-temperature composite materials, mainly cermets, high-temperature inorganic coatings fiber-reinforced ceramics.