Rotary kiln shell generates high temperature locally, what should we do

Rotary kiln is a new type of equipment commonly used for calcination of cement, lime, calcium carbonate and other materials. Generally, coal, gas, natural gas, etc. are used as combustion methods. However, due to the high temperature in the kiln, improper operation or untimely treatment, it will not only affect the service life of the rotary kiln, but also shut down the kiln for maintenance, increasing the maintenance cost of the enterprise!

How to deal with the high temperature generated locally in the rotary kiln shell? When the high temperature occurs locally in the rotary kiln, theoretically the red kiln must be stopped, but for some high temperature and small areas of reddish, we have adjusted the process parameters and added air cooling, etc. The method can lower the temperature, repair the kiln skin, and continue production, which greatly reduces operating costs.

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1. Treatment when the local high temperature is lower than 400℃

When the local temperature is high, but lower than 400℃, it indicates that the refractory bricks have not completely fallen off, but have become thinner. At this time, it is recommended to use air coolers or high-pressure air ducts to cool down to reduce the temperature and then auxiliary reductions. If the kiln speed is slow, there is no problem in repairing the kiln skin.

2. Treatment when the local temperature is higher than 400℃

When the local temperature is higher than 400°C, the risk is greater, and the process parameters must be adjusted in a larger range. For example, the feed rate of the 2500t/d kiln can be reduced by 20-50t/h, so that the filling amount of materials in the kiln is reduced, the flow cross section of the air flow is increased, and the flame is smooth; the low kiln speed can be reduced to 2.0r/min, allowing high temperature Make up the kiln skin as soon as possible at the point location; the amount of head coal can be reduced by 2~3t/h, but it must be ensured that the thermal system in the kiln is stable to prevent yellowing powder; the head of the burner can be lowered by 10~20mm , Make the flame closer to the material, reduce the burning of high temperature points, the section of the inner and outer cylinder can be adjusted to 50~60mm, the ratio of the inside and outside air can be adjusted to 0∶100%~20%:100%, and the burner can enter the kiln or retreat 0.4m away from the kiln mouth, so that the fire point moves forward or backward greatly. 

In addition, high-pressure air ducts and air coolers are used for cooling on site, and the laboratory adjusts the composition of raw materials to increase the amount of liquid phase.

If the temperature rises and falls repeatedly and is unstable in the local high temperature point, when it is determined that the position of the air duct has not changed and the fan is not stopped, the hydraulic baffle wheel can be stopped to fix the kiln body in the lower position, and then recalibrate the high temperature point position, fix the fan, The air pipe is blown and cooled, so as to eliminate the possibility of high temperature points moving due to the up and down movement of the kiln body. During the stop of the wheel, pay close attention to the change in the temperature of the supporting roller, and the time should not be too long, and it should be opened in time after the high temperature drops.

In order to ensure the normal operation of the rotary kiln, daily maintenance is very important. Therefore, after the rotary kiln has been running for a period of time, the operator must inspect the cylinder to ensure the wear status of various parts in the kiln, and make records to prevent it. The failure occurred!