To keep your rotary kiln rolling smoothly, and to prevent potential damage to the shell or lining, it’s important to keep your trunnion rollers in good condition! Your kiln relies on those rollers for smooth rotation. If they begin to break down or have signs of damage, it will quickly degrade the performance of the kiln itself.
At Kiln Technology Company Co, we have decades of experience maintaining kilns and their rollers. These are some of the warning signs of damage we look out for, and issues that you can avoid.
Three Frequent Issues with Kiln Trunnion Rollers
1 – Avoidable wear
While trunnions will slowly wear down from use over time, a poorly maintained kiln can quickly contribute to their wear and drastically reduce their overall lifespan. The most common way this happens is if the kiln drum is unbalanced, or misaligned. This causes uneven load on the trunnions, with those taking the greater load suffering much more damage as a result. Frequently balancing your kiln will prevent unnecessary wear.
Fortunately, wear is easily seen simply by looking at the trunnion rollers. Look for pitting, scratches, spalling, or filming marks. Damaged rollers should be repaired or replaced ASAP before the problems get worse.
2 – Frequent grinding
When trunnion rollers need to be repaired, such as removing pits and scratches, grinding is the typical solution. The top layer of the roller is removed, to smooth out what remains. Unfortunately, every time this is done, it shrinks the trunnion roller slightly. Over time, the trunnion will become too small for its job, and begin unbalancing the kiln.
The only solution here is replacing the trunnions, so this is another reason that protecting them from wear is so important. One way or the other, wear reduces their lifespan.
3 – Excessive Skewing
Skewing is a change in the tilt of the rollers, to ensure the kiln drum is floating properly in place, without drifting. However, it’s easy to over-skew the rollers, which puts a lot of extra strain on them.
This damage can be seen on the trunnion rollers themselves, creating a diagonal pattern of wear that resembles snakeskin. Over-skewing can be corrected by re-aligning the rollers but undoing the damage may require grinding.