In the calcination process, the sintering temperature of the new dry cement clinker reaches about 1450, and the gas temperature of the sintering belt of the rotary kiln reaches over 1,700, or even nearly 2000. Many working parts have to bear the mechanical erosion and chemical erosion of high-temperature materials for a long time. However, the new dry kiln system in China's cement industry still lags far behind foreign countries in choosing refractory materials, such as chrome-free bricks and refractory prefabricated parts.
5000 t / d new dry process cement clinker production line, its kiln tail smoke chamber and decomposition furnace cone, tertiary damper valve, grate cooler throat, grate cooler wall and other parts have used traditional refractory castables, but These vulnerable parts are affected by the harsh process conditions of the cement kiln and the wind speed in the kiln, the composition of the flue gas and the dust content, the hardness of the particles, the temperature fluctuation and other factors, plus the corresponding chemical erosion, erosion wear, mechanical stress and thermal peeling. The service life is generally not long. Premature failure of refractory castables often occurs, greatly reducing the operating rate of cement kiln and clinker production, increasing the number of inspections and maintenance costs of shutdown kiln, and the chain reaction affects the service life of refractory materials in other parts. In this case, refractory preforms have attracted the interest and attention of technicians as a unique technical solution.
The refractory prefabricated parts divide the pre-construction parts into small pieces in advance, and design a special shape. The molds are made according to the shape, pre-casting in the manufacturing factory, and after being cured and baked, they are transported to the construction site for hanging and assembling. We believe that the scientific use of refractory prefabricated parts will change the installation method of on-site pouring construction of traditional castables, making on-site construction simple and easy, eliminating the need for on-site mixing, pouring or beating and corresponding equipment, saving construction time and enabling on-site construction. The impact on the construction environment and the season is greatly reduced to ensure the construction quality.
Due to the harsh working conditions of the refractory materials in the key parts of the cement kiln, high construction quality is required during the construction process. During the maintenance of cement kiln, the general construction period is short, the construction quality of on-site pouring is difficult to guarantee, and the quality of construction has a great influence on the service life of refractory materials. The increase of water addition will increase the porosity of the castable, reduce the strength, and seriously affect the wear resistance of the castable. After the construction of the castable is completed, it must have a certain curing time. After the curing is completed, it must be baked, otherwise it will be easy to burst. These shortcomings of on-site construction of castables not only affect the service life of the refractory material, but also prolong the inspection time.
In order to make full use of the refractory prefabricated parts, the construction is simple and convenient, the construction quality is controllable, the materials are saved, the equipment maintenance time is saved, the efficiency of the cement kiln is effectively improved, and the need for energy saving and consumption reduction is finally selected. In combination with the degree of damage of the castables in each part, the refractory castables are modified one by one.
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