Article Reprinted from World Cement, January 2010
How Should One Lubricate Kiln Tyres - World Cement, January 2010, p.92 (PDF)
Question: How Should One Lubricate Kiln Tyres?
Karl Bruno, Senior Sales Representative, Petron Corporation, replies
Lubrication of kiln tyres is an important part of overall kiln maintenance. It is proven to reduce wear that results from scoring of the inside bore of the kiln riding ring. When properly used with the latest technologies, it can slow wear of filler bars, stop blocks and eliminate breakage of filler bar welds. There are two methods to lubricate kiln tyers.
Method one has been used for many years and involves mixing graphite powder with a liquid (most commonly water). This solution is applied between the filler bars or kiln shell and riding rings of a rotary kiln via an air pressurised spray wand. It is difficult to maintain consistency of mixture between applications and to control the amount of lubricant applied during each application with this method. Applying lubricant to a kiln tyre in this manner is also time consuming and occasionally presents issues with housekeeping. This method does not guarantee that lubrication is precisely delivered to where it is needed most and intervals between applications are sometimes arbitrary.
Method two is the latest and most effective technology. It involves applying a solid bar of lubricant between the filler bars of a rotary kiln. The bar melts upon contact and the rolling action of the kiln distributes solid film forming lubrication to the surface of its filler bars, ring bore and stop blocks. A thin temperature-resistant film creates a barrier between these moving surfaces, filling in microscopic imperfections and assuring protection from cold welding and galling.
Installation involves placing a whole bar between the filler bars or pads at the five or seven o'clock positions every quarter turn of the kiln as it travels through one full revolution. The number of bars used per tyre/pier may vary depending upon the operational parameters of a kiln. These parameters can include speed of rotation, temperature and load of the kiln shell itself. The shell of the kiln should be at or above 125 degrees Fahrenheit, when the bar is applied. Standard frequency of application is four bars per tyre pier per week.
Solid bar lubrication between the filler bars or kiln shell and riding rings of a rotary kiln is proven to:
- Extend the life of wear filler bars.
- Extend shell and refractory service life.
- Reduce scoring of kiln tyres and stop blocks.
- Reduce weld fractures at filler bar and kiln shell interface.