The role of the rotary kiln coating

　　kiln coating is changed from clinker or dust from liquid phase or semi-liquid phase to solid. Its main functions are:

　　1. Protect the refractory bricks so that the refractory bricks are not directly subjected to high temperature and chemical erosion.

　　2. Store heat energy, reduce the heat loss from the kiln shell to the surroundings, and improve the thermal efficiency of the rotary kiln.

　　3. As a heat transfer medium, when the kiln coating is exposed to the air and in contact with high-temperature air, it absorbs heat by radiation or convection. When the kiln coating is in contact with the material at the bottom, it transfers heat to the raw material by conduction. material.

　　4. The surface of the kiln coating is rough, which can reduce the flow rate of the powder and prolong the reaction time of the material in the kiln.

　　The main factors affecting the formation of kiln coating are:

　　1. The chemical composition of the material The kiln coating is the product of the process of changing the liquid phase into a solid phase. The aluminum and iron components are more, the liquid phase is more, and the kiln coating is easy to form. The composition of aluminum and iron is relatively small, and the amount of liquid phase is small, so it is difficult to form a kiln coating. There is more aluminum in the raw material, and the viscosity of the liquid phase is high, so it is difficult to form a kiln coating, but once formed, it is relatively strong. There are many iron materials in the raw materials, the viscosity of the liquid phase is relatively small, and the kiln coating is easy to form, but the formed kiln coating is also easy to fall off.

　　2. Flame temperature If the flame temperature is low, the liquid phase formed by the material is relatively small, and it is difficult to form a kiln coating. If the flame temperature is too high, the temperature of the kiln coating will be higher than the solidification temperature of the liquid phase, and the kiln coating will easily fall off.

　　3. The shape of the flame The temperature of the kiln shell is affected by the shape of the flame and the heat dissipation of the kiln shell. Generally speaking, flames that are too short, too fast, and too wide are harmful to the erosion of the kiln coating, while long flames are more beneficial to the kiln coating, but they will disperse the heat of the kiln, which is not good for firing.

　　Therefore, during operation, it is necessary to maintain a certain reasonable flame shape and position, strictly control the clinker granulation, prevent large pieces from washing the kiln coating, stabilize the thermal system in the kiln, and prevent ring formation. Loops should be dealt with in a timely manner.

　　Shedding and redness of kiln coating

　　The kiln coating will fall because the temperature exceeds its own solidification temperature, and sometimes it will fall with the fire bricks due to uneven heating. The main reasons for the fall are:

　　1. Unstable feed composition and feeding amount or fluctuation of output lead to unstable kiln temperature. If the fed material is easy to burn for a while, the temperature in the kiln will be high, and when it is not good to burn, the temperature will be low. When the amount of material is large, the temperature is low, and when the amount of material is small, there is no material to absorb the excess heat. In this way, the temperature fluctuates, causing the kiln coating to expand and contract unevenly, and it is easy to fall off.

　　2. The wrong operation procedure is mainly caused by improper adjustment of the shape of the flame.

　　When it is found that the kiln coating has fallen off, you can judge it by checking the temperature of the kiln shell in the central control room. Generally, the temperature of the kiln shell is about 200-300 degrees. If there is a place where the temperature is too high, the kiln coating may fall off. When the kiln coating is removed, it is necessary to immediately take measures to remedy the kiln coating, immediately reduce the amount of coal injection, or change the shape and position of the flame. On site, blowers or compressed air can be used to cool the kiln shell that has lost the kiln coating. The fan should be placed at four points or The position at eight o'clock (here is the position of the material flow), the closer to the place where the kiln coating falls off, the better.

　　The shedding of the kiln coating will greatly damage the refractory materials of the rotary kiln. If the refractory materials of the rotary kiln are to last longer, it is even more necessary to reduce the fluctuations in the production of the rotary kiln, including medium, temperature, output, etc. Zhengzhou Zhenjin Company is committed to the provision, construction and installation of refractory products in cement, lime, non-ferrous smelting, steel, glass and chemical industries. The refractory materials produced have the characteristics of good wear resistance and strong peeling resistance. , has been well received by customers.