Influence factors of hanging kiln skin in rotary kilnDate: 2019-11-01 Views:
Hanging kiln skin is the process of liquid solidification to the surface of refractory brick.Therefore, the amount of liquid phase of clinker firing directly affects the formation of kiln skin, while the chemical composition of raw material directly affects the amount of liquid phase and its viscosity.In normal operation of rotary kiln, the primary air volume is small and the secondary air temperature is high.Influence factors of hanging kiln skin in rotary kiln.
1. Firing temperature and flame control
In addition to a certain amount of liquid phase and liquid phase viscosity, the main factors of good hanging firing belt kiln skin should also be appropriate temperature. There should be a certain temperature difference between airflow, materials and firebrick.Generally, the firing temperature should be controlled in normal production of rotary kiln.Grasp the clinker granule small and uniform, not burning large can not burn flow, strictly prohibit running raw materials.The lifting weight is controlled within the normal production target.Keep the firing temperature stable, kiln speed stable, flame shape complete and smooth.Such rotary kiln hanging out of the kiln skin thickness consistent, flat, uniform, strong.
2. Feeding amount and kiln speed
In order to make the kiln skin hang firmly, evenly and evenly, the stable thermal system in the rotary kiln is the prerequisite.The stable feeding quantity and the stable kiln speed are very important during the hanging process.If the feeding amount is too much or the kiln speed is too fast, the temperature in the rotary kiln is not easy to control, and the bonded kiln skin is not smooth and firm.Therefore, the initial feeding amount and kiln speed of the first hanging kiln skin of the new kiln can best control about 35% of the designed output.After hanging to a certain extent, then depending on the kiln skin adhesion hanging situation gradually and slowly increased.
3. Nozzle position during kiln skin hanging
Under normal circumstances, nozzle position should be as far as possible in front (outward pull) a little, at the same time slant material, flame should be short should not be long.This high temperature area is concentrated, the high temperature point is near the front, so that the kiln skin from the rotary kiln before gradually into the kiln.With the increase of raw feed, the nozzle should move to the rotary kiln.When the output of rotary kiln increases to the normal condition, the nozzle also moves to the normal production position.Do not hang the kiln skin during the flame is too long, otherwise the high temperature area is not concentrated, the kiln skin hanging far or before thin after thick, or even the front kiln skin has not been hung, the back has formed a ring and other adverse conditions.
4. Adjustment of rotary kiln flame
At present, most of the pre-decomposition kilns adopt three-channel or four-channel burners, and the flame shape is adjusted by proper matching of internal and external air.As the decomposition rate of raw material CaC03 in the pre-decomposition kiln has been up to about 90%, the general outflow wind speed should be appropriately increased, so that the firing zone can be controlled a little longer, which is conducive to the pre-burning of materials with high silica content and the formation of fine homogeneous clinker particles.If it is necessary to shorten the flame to make the high temperature zone concentration of some or poor coal quality, burning speed is slow, can appropriately increase the internal wind, reduce the outflow wind;If the coal quality is better or the kiln skin is too thin, the rotary kiln simplified surface temperature is on the high side, the need to lengthen the flame, it should increase the outflow wind, reduce the internal flow wind.However, when the outflow air volume is too large, it is easy to cause the flame to be too long, resulting in too long floating kiln skin, easy to form the back ring, and the temperature at the end of the rotary kiln will be too high.Excessive internal air flow, easy to cause the flame coarse, divergent, not only the kiln skin is easy to be ablated, top fire forced burning also easy to produce coarse clinker and yellow core clinker.
In a word, the flame temperature and flame shape in the kiln should be observed and adjusted frequently to meet the needs of actual production.