Name: Liaoning Ming Yan new material manufacturing Co., Ltd.
Contact: Manager Mu
Mobile phone: 13940737885
Address: Guan Tun Village, Guan Tun Town, Dashiqiao City, Yingkou, Liaoning
What are the different ways of refractory gunning materials?
1. Wet spraying is a method of mixing refractory aggregates, binders, additives and water to make mud with a certain consistency, and then spraying the mud to the spraying surface with compressed air through the spraying machine. Its characteristics are simple operation, high adhesion rate and quick sintering. But because of the large water content and fine grain, the shrinkage is also large. At the same time, because the spray coating is thinner, the durability is not good.
2. Semi-dry spraying is a method of mixing refractory aggregate, binder and additive with water through the water ring hole at the spray gun end and spraying compressed air to the spray patch surface. The amount of water can be adjusted at any time according to the spray patch situation, generally fluctuating between 10 and 20%, which is lower than that of wet spraying patch. It's much more. Therefore, the spraying layer with high volume density and small shrinkage can obtain a thicker spraying layer with better durability, but the springback is slightly higher than that of wet method.
3. Flame spraying is a repairing method by which refractory aggregate, flux or heating agent are conveyed to the nozzle by compressed oxygen, and the refractory aggregate particles are instantly heated to a melting or semi-melting state by burning the mixture of high calorific value fuel and the refractory aggregate particles, and then sprayed and adhered to the furnace lining. Dense, high strength, corrosion resistance, anti erosion ability, solid and durable. But the flame gunning device has high cost, complex technology and high energy consumption.
The most important part of the coke oven body is the carbonization chamber. The reason for the direct damage to the brick wall is the abnormal transverse pressure of the furnace wall when the coke is sprayed with repairing material. The brick wall of the coke oven is usually built with silicon brick. The silicon brick has good thermal stability at 600-1400 C and low thermal stability below 600 C. In the production process of the coke oven, the cycle of the furnace door is low. The effect of opening is that the furnace wall is suddenly hot and cold, which causes cracks in the walls of the furnace walls to produce stress.
The wall surface of the carbonization chamber was smooth and smooth, but when the furnace wall cracked, the friction damage of coke and the mechanical force of pushing coke caused the crack to expand quickly, and when serious, it would cause brick drop or fall off. The main damage forms of coke oven coking chamber are cracks, holes and bricks drop. Repairing the wall of coke oven coking chamber is a simple and feasible method to prolong the service life of coke oven. The traditional wet thermal repair method uses sodium silicate mud or phosphoric acid mud as repairing material, but it is difficult to repair operation and hanging time. When the mud is peeled off, the area of the karst cave increases and the operation is not able to operate at low temperature. Flame repair is very effective for deep crack, vertical crack of furnace wall, crack of furnace top and temperature change little, but it has the disadvantages of poor resistance to quench and heat, difficult operation and high cost. The spraying method of high temperature material has the advantages of high refractoriness, good cohesion and plasticity, hard hanging, long hanging time and good repair smoothness. It also has the disadvantages of easy precipitation of coarse grains, more dropping materials, difficult operation of spraying material as well as more cracks and bubbles on the repair surface.
Semi-dry spraying technology is a relatively advanced foreign coke oven repair technology, it overcomes the shortcomings of the original technology, but at present all the domestic use of spraying materials are imported, expensive, confidentiality formula. China Patent CN91108201 introduces "a wet flame spraying method for refractories". The wet flame spraying method reduces the adhesion of the spraying and affects the spraying effect. Using sintered magnesia as raw material, bauxite cement as binder and alkaline spraying material with some reinforcement additives, the effect of spraying and repairing on double chamber lime kiln is better, and the service life of shaft kiln is prolonged. The importance of gunning on prolonging the life of blast furnace and the special properties of gunning material such as bonding strength, wear resistance and CO corrosion resistance are described. The influence of these properties on the gunning effect of blast furnace is analyzed.