Our company is recognized as one of the proficient Service Providers involved in rendering services for Kiln Tyre Grinding. Usually, question being asked for need of grinding of tyres and reasons attributed for change in shape of tyre raceways from square to convex / concave because of followings :
The abnormalities in kiln operating conditions, like :
- High shell runout
- High tyre wobble
- Misalignment in kiln axis
- Improper support roller axis, etc
Tyre wobble also called as tyre axial runout or tyre throw and usually consequence of installation error, kiln shell bend thermal or mechanical taper wear on chair pad etc.
Tyre wobble leads to reduced contact between tyre and support roller in part of kiln revolution. The reduced contact result in higher hertz pressure on rollertyre surface and has its own consequence and causes accelerated wear on rolling surface and adversely affects kiln axial balancing as well. From the figure, it is obvious the wear is convex on tyre and concave on support roller. The wear begins series of problems like hot bearings, failure of tyre retainers, accelerated wear of raceways etc. Once wear pattern established, accelerated wear can be expected in order to adjust kiln axial movement by adjustment of the worn out support rollers.
- Obvious solution for the above anomaly is to restore square tyre and roller raceways.
- Supports rollers are expected to operate about an axis and the resurfacing is relatively easy.
- However, the resurfacing for the tyre is not easy because of wobbling in lateral and axial direction. And, tyre was removed from position and bored in vertical boring machines and reinstalled. As the methodology is not economical, an innovative approach is required beyond normal machining methods and tyre grinding machine is developed for the resurfacing.
Tire Resurfacing Technique
- Utilizes CUP grinding stone
- Methodology adopted is more or less similar to centre less grinding machine
- Senses highs and lows on tyre surface
- Ensures uniform grinding stone pressure on tyre surface
- ASEPL not guaranteeing the lasting of the effect of regeneration nor proper object’s operation, in case of presence of :
- Wobbling of the live ring (its axial run out) resulting in alternating contact at inlet/outlet end of tyre / support roller.
- Appearance of gap on raceways contact line with support rollers;
- Wrong positions of support rollers in vertical and/or horizontal plane;
- Wrong position(s) of the thrust roller(s);
- Improper shape and/or positioning of the element cooperating with the regenerated element, especially when we do not know detailed technical state of the whole drum;
- Excessive permanent or cyclic loads during exploitation of the object in reference to the ones adopted in calculations / strength analysis;
- Defects in the material of grinded elements, especially when before grinding it was not executed any non-destructive testing and/or strength analysis;
- Improper conditions of object exploitation or force majeure.
Execution of the Grinding :
- Therefore ASEPL recommends to execute appropriate study preceding the decision of resurfacing preferably by carrying out kiln audit. The audit is being carried out during kiln in normal operation and NO STOPPAGE is requires or LOSS OF PRODUCTION is expected during above services.
- In each case decision about service’s stoppage is consulted with the orderer and/or object’s owner and requires preparation of appropriate protocol to confirm that it is to be taken up jointly.