Kiln Trunnion Roller Resurfacing
NAK Kiln Services provides complete field services for trunnion roller resurfacing to resurface and kiln tire roller parts.
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Kiln services throughout the USA
Trunnion Roller Resurfacing
Wear on the surfaces of the kiln tires and support rollers makes it difficult, if not impossible, to make support roller adjustments to achieve a proper alignment.
An ideal hot kiln alignment involves not only the horizontal and vertical axis of the shell, but the balance of the axial thrust of the kiln as well. When tires and support rollers are worn on the contact surfaces, making roller adjustments and training for axial thrust becomes a delicate process. In some cases, moves to correct the alignment cannot be made effectively. Fortunately, excessive wear of tires and support rollers can be eliminated during the process of resurfacing.
Concave and convex wear present the most common problem in kiln tire and support roller wear.
The relationship between the surfaces of the support rollers and the face of the tire when the roller shafts are skewed to control the axial thrust of the kiln. Note that the axis of the roller shaft is no longer parallel to the axis of the tire. Consequently, the edges of the tire on both sides of the face will have higher load concentrations than at the center of the tire.
After the kiln operates in this condition for some time, the tire will have accelerated wear on its edges, giving it a convex shape. Since the support rollers are wider than the tire, the surface of the rollers will develop concave wear. Since this is the desired adjustment position of the rollers to control the axial thrust of the kiln, this kiln design makes concave and convex wear inevitable.
The tire and support roller resurfacing process has been offered by NAK for more than 20 years. We have state of the art grinding equipment to resurface ties and support rollers to OEM tolerances. We have been active in several seminars and have published numerous articles related to tire grinding.
As part of our grinding service, we measure the shell ovalities, thoroughly inspect the balance of the kiln, and make roller adjustments to correct kiln misalignment caused by the decreases in the tire and roller radiuses. As is the case with our alignments, the grinding procedures do not require kiln downtime.
All measurements and repairs are done with the kiln in full operation and a "no fine print" guaranteed price.
A properly designed grinding machine with a cup grinding stone is designed to sense the highs and lows in the surface of the tires and rollers as it traverses the face. The machine has devices that sense the out-of round conditions on every tire. With this type of machine an operator can machine a tire in a manner that eliminates timing marks as well as the highs and lows in the surface while reducing the chatter caused by inconsistent machining conditions- commonly found in sanding style of grinders.
It is important to realize how the resurfacing process complements the hot kiln alignment process. The hot kiln alignment will not have the best results without alleviating the wear conditions on the tires and support rollers. Removal of the wear makes it possible to complete the alignment and reach optimum mechanical stability and efficiency of the kiln. With the two processes combined the components will be relieved of accelerated wear and normal production of the kiln can be achieved with less energy.
Because of the energy savings generated by the resurfacing, payback for the alignment and resurfacing work can be only one year. Since all work can be performed during normal production, no costly downtime is needed and plant operation is uninterrupted. This resurfacing process is just one more way to increase the effectiveness of the kiln operation and also save maintenance dollars and energy costs for years to come.