Whether the calcination in the rotary kiln is normal or not depends on whether the thermal system in the kiln is reasonable, that is, whether the drying belt, pretropics, decomposition belt, exothermic reaction belt, firing belt and cooling belt in the kiln have completed their respective thermal tasks.When the temperature or length in one area is not enough, the other zones will be affected, thus causing instability of the thermal system and affecting the normal calcination of the kiln.
There are many factors affecting the thermal system of rotary kilns, mainly in the following aspects:
1) change of raw material composition to change its fire resistance.
2) the feeding is uneven, and the operation of the upper wind and the coal cooperation cannot be adjusted in time, resulting in temperature fluctuation of the kiln.
3) the quality of coal powder changes or the uneven feeding of coal, and the addition and reduction are not timely, resulting in large temperature fluctuations in the kiln.
4) improper coordination of wind coal, resulting in incomplete combustion of coal powder, resulting in low temperature of sintering zone and high temperature of kiln tail.
5) unreasonable use of exhaust air, too small, too large, or too frequent change will cause the temperature fluctuation of the kiln end, which will lead to uneven preheating of materials and affect the sintering.
6) improper location of coal injection pipe, difficult to control operation.
7) improper master of kiln speed without timely adjustment.
8) it is easy to break the thermal system when winding or removing a large number of long kiln skins due to insufficient attention to operation.
9) the operation of class 3 is not unified, and the temperature of the kiln is not normal during the shift, resulting in temperature fluctuation.
In case of problems in operation, the cause should be analyzed to solve the main contradiction in order to quickly stabilize the thermal system of the kiln.