Kiln Tyre Lubricant
Rotary kilns in the industrial sectors such as Cement, Steel, Refractory industry, Pulp production or the Chemical industry are usually in operation for 24 X 7 for around months together continuously. The kilns are exposed to extreme conditions of shell temperatures to max 350 째 C.
Many kilns are designed with loose tyres (called riding rings). The ring rides on sacrificial elements called chair pads. Relative movement between the ring and chairpad causes wear on both the mating surface due to scuffing, galling. And, presence of dust with absence of suitable lubricant around the riding ring accelerates the wear. The wear causes an increase of air gap leads to increase in tyre migration.
Plant maintenance manager has a task to control the migration as the increase may eventually consequence in refractory failure, circumferential shell crack, Tyre crack etc. Unpredictable outages substantially increase the cost of Maintenance includes loss of production, etc, further disrupt the delivery schedule as well, cost dearly to the management.
Best solution to mitigate the above unscheduled outage is to reduce wear by ensuring suitable lubricant between the tyre ID and Chairpad OD.
In plant conventional method of the lubrication of kiln tire / riding ring is the spray of water-based Graphite powder or applying copper base grease manually using a spatula. Presence of grease at the position attract dust and can adversely affect the intended lubrication. Some times grease upon the application grease catches fire or oxidizes, makes the lubricant improper for the intended application. Also, upon application on the grease it smeared on tyre side face and gradually spread on the tyre / roller raceways results in:
- Kiln downward movement, improper kiln float, kiln requires excessive pressure to move uphill, Kiln not moving uphill etc.
- Also, presence of grease on raceway (pinch point) makes raceways crack due to hydraulic pumping action, as the oil (in grease) is incompressible liquid.
Lube bar is specially developed for the chairpad lubrication. It is a bar usually in size 300 X 50 X 12 mm. The Lube bar Lubricant is a specially formulated, blend of graphite, copper flakes and soft metal powders enclosed within a wax. When applied on kiln it dissipates and simultaneously lubricates both the support pad outside diameter and the kiln tire internal diameter.
It is easy to apply between kiln shell and riding ring. Approx 5 to 6 bar to be inserted in one lubrication cycle and that can be applied in one revolution of the kiln. Lube Bar starts melting at 50 to 60 degree centigrade and the film smeared on the mating surface, further lubricating for a longer period.
Benefits of application of Lube Bar
- Minimizes friction across the mating surface, tyre bore and Chairpad OD.
- Decreases tyre retainer pressure