PROBLEM: THE ENTIRE triangular belt, OR A LONG SEGMENT OF IT, RUNS TO ONE SIDE (MISTRACKING)
Here again, there are many factors that may cause an entire triangular belts (or long section) to run to one side:
Potential Cause: The structure may be out of alignment, or not level transversely.
Fix: Check and correct.
Potential Cause: It’s possible the belt is not cut and spliced squarely. Similarly, the belt could be bowed as a result of poor storage conditions.
Fix: In the case of new belt conveyors, operate under the full load tension for the “break-in” period. If condition persists, a new, higher-quality belt may be required. For bowed triangular belts, a complete replacement is necessary.
Potential Cause: Material is being loaded on the belt conveyor off center.
Fix: Correct the cause at loading point.
Potential Cause: Belt is tensioned improperly.
Fix: Adjust the pulleys as needed.
PROBLEM: BELT IS RUNNING ERRATICALLY
Potential Cause: The belt may be too stiff to train. Alternatively, improper belt tension could also be causing the belt to run improperly.
Fix: Check quality manufacturer of belt for proper specifications on conveyor. Check belt tension and adjust pulleys as needed.
Potential Cause: Twisting of frame on portables and stackers.
Fix: Brace loading hoppers so load and loading stresses do not allow frame to twist out of line. Adjust belt tension.
PROBLEMS WITH BELT WEAR
PROBLEM: EXCESSIVE STRETCHING
When a belt is exhibiting extensive stretching, there are two primary causes:
1.Belt tension is too high.
Many factors can cause the tension to be too high, and as such, there are many potential ways to resolve the issue:
Increase the belt speed, while maintaining the same capacity.
Reduce the tonnage while maintaining the same speed.
Install drive pulley lagging.
Use less weight on gravity take-up, or less tension on screw take-up.
Check for worn idlers or spilled material.
Check tonnage capacity and belt tension against belt specs.
Check tensions at skirts
2.Belt construction is too light.
To confirm that belt construction is too light, check the tonnage capacity and belt tension against the belt specifications. The fix in this case is to replace the belt with one of adequate specifications.
PROBLEM: THE BELT IS EXHIBITING SEVERE WEAR ON THE PULLEY SIDE.
Potential Cause: Idlers may be sticking, or the impact or load zones may be worn. Overloading could also be occurring.
Fix: Replace bad rolls. Improve maintenance practices. Reduce loading if necessary.
Potential Cause: Material is being allowed to spill onto the return belt.
Fix: There are many potential ways to resolve spillage of material on the belt. This includes:
Use of a sealed hopper
Install a self-cleaning tail pulley
Return belt covers
Prevent sloppy loading with deep trough idlers
Add a return plow prior to the tail pulley
Potential Cause: The head pulley fasteners could be protruding.
Fix: Replace worn lagging.
Potential Cause: Slippage may be occurring on the drive pulley.
Fix: Use rubber lagging on the drive pulley. Use grooved or herringbone type. If needed, install a snub pulley to increase drive pulley contact.
PROBLEM: THERE ARE SHORT BREAKS IN THE CARCASS.
Potential Cause: Similar to the previous issue, breaks in the carcass could indicate a loading impact from sharp lumps.
Fix: Reduce the loading impact and employ impact idlers or bed.
Potential Cause: The chosen belt is not a good fit for the application.
Fix: Replace the belt with one more suited to the application.
Potential Cause: It’s also possible that material is getting between the belt and the pulley.
Fix: If this is the case, improve maintenance practices to reduce fugitive material between belt and pulley.
PROBLEM: BREAKS ARE OCCURRING AT THE BELT EDGE.
Potential Cause: Belt edges may be “folding up” on structure at or near pulleys.
Fix: Retrain belt properly.
Potential Cause: Material is jamming under the hopper or skirt boards.
Fix: Adjust for proper clearance and relief.
Potential Cause: The final idler is too close to the head pulley or too high.
Fix: Adjust final idler location or height.
Potential Cause: A sharp, convex curve is present in the system.
Fix: Adjust to a more gradual curve.
PROBLEM: BELT EDGE IS EXHIBITING WEAR
Potential Cause: When a belt exhibits wear at the edge, it is often a sign of misalignment, which can allow the belt to run out of line and rub against a structure.
Fix: Follow recommendations for correcting belt alignment. Retrain as needed.
PROBLEM: BELT IS EXHIBITING TRANSVERSE BREAKS NEAR FASTENERS
Potential Cause: Fastener plates are too long for the pulley size. (For mechanical splice only)
Fix: Use correct lacing and/or use larger pulleys.
PROBLEM: EXCESSIVE “CUPPING”
Cupping occurs when the edges of the belt curl up. Cupping is expected as a part of normal wear and tear over time, but excessive cupping could be an indication that something is wrong. There are many reasons why a belt may exhibit excessive cupping:
Potential Cause: The belt may be over-tensioned.
Fix: Reduce take-up tension or counterweight on gravity take-up. Check for drag from stuck idlers. Reduce loading rate or increase belt speed to reduce tension. Make certain that the belt is adequate for the tension requirements.
Potential Cause: Deep trough idlers and a low elasticity in belt fabric are causing high tension.
Fix: Use adjustable transition idlers at terminals for longer transitions between deep trough and pulleys. Use belting with moderate stretch. Ensure proper transition distances.
Potential Cause: Belt has been stretched or is worn out.
Fix: Replace belt.
Potential Cause: The top cover is too heavy for the thin-ply belt.
Fix: Consult a quality belt manufacturer.
PROBLEM: BELT IS HARDENING AND/OR CRACKING
The hardening and/or cracking of a rubber triangular belt is a result of exposure to heat. To resolve the issue, use a Neoprene hot hexagonal belts. Use oil for lubrication.
December 4, 2020- -
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