An Introduction of Rotary Kiln’s Major Parts and Main Structure

Kiln Shell
Kiln shell is the main part of 
rotary kiln, near the riding rings and made by 40-ish mm thick steel plate so as to bear a tremendous weight. Besides, the inner of kiln shell contains a layer of 200-ish mm refractory bricks. When the kiln shell is operating, there will be an elliptical deformation due to high temperature and heavy weight, which will generate pressure to kiln bricks and reduce their service life. The last one meter of kiln tail is designed as a taper, so that materials from preheater’s feeder are able to enter the kiln smoothly.
Riding Rings and Rollers
Riding rings, which attach to, but is not fixed with the kiln shell, along with gyro wheel, axletree, are used for bearing kiln. Riding rings and kiln shell are separated by a steel plate, and keep a certain distance. (If the distance is too close, the kiln shell’s inflating will be confined by the ring, which will easily damage the kiln bricks; whereas if the distance is too far, then the relative movement and grinding between the kiln shell and the riding ring will be more frequent, this will also cause serious elliptical damage to the kiln shell. Normally, you need to lubricate these two.) The deformation degree of the kiln shell can be estimated by the relative movement between kiln shell and riding rings.

Pyroconductivity discrepancy between kiln shell and riding rings must be decreased by an external fan that dissipates the heat from kiln shell, otherwise, the inflation of the kiln shell will be confined by the riding ring. Before opening the kiln, the heating rate of the kiln shell is higher than that of the riding ring, so the kilnman have to control the rate at 50℃/h in the case of protecting kiln bricks.  

The riding rings, generally, are 50-100 mm wider than the 
tyre. The axletree of roller is made by Babbitt metal, the axletree will be burnt if the part is lack of lubrication. In order to reduce the heat radiation from the kiln shell that overheats the riding wheel, there is circulating water coolant near the axletree and thermal baffle between these two for cooling.
Thrust Rollers
The uphill and downhill of rotary kiln are resisted by thrust rollers. Because the support wheels are wider than the 
tyre, for an even moving of both the riding wheel and tyre, the thrust rollers are installed in front of riding rings.


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