Conveyor Problem Solving
Cause and Remedy
- Build up of material on idlers: remove accumulation; improve maintenance, install scrapers or other cleaning devices.
- Sticking idlers: free idlers and improve maintenance and lubrication.
- Idlers or pulleys cut-off square with center line of belt. Re-adjust in affected area.
- Conveyor frame of structure crooked. Straighten affected area.
- Idler stands not centered on belt: readjust in affected area.
- Structure not level: level structure in affected area.
Cause and Remedy
- Belt not joined squarely; remove affected splice and re-splice.Pulley lagging worn: replace pulley lagging.
- Bowed belt: for new belt this condition should disappear during break-in, in rare instances belt must be straightened or replaced; check storage and handling of belt rolls.
Cause and Remedy
- Belt running off-center around the tail pulley and through the loading area: install training idlers on the return run prior to tail pulley.
- Off center loading or poor loading: adjust chute to replace load on center of belt; discharge material in direction of belt travel at or near belt speed.
- Conveyor frame of structure crooked. Straighten affected area.
- Idler stands not centered on belt: readjust in affected area.
Cause and Remedy
- Belt running off-center around the tail pulley and through the loading area: install training idlers on the return run prior to tail pulley.
- Material spillage and build-up: improve loading and transfer condition; install cleaning devices, improve maintenance.
- Idlers or pulleys cut-off square with center line of belt. Re-adjust in affected area.
Cause and Remedy
- Pulley lagging worn: replace pulley lagging.
- Material spillage and build-up: improve loading and transfer condition; install cleaning devices, improve maintenance.
- Idlers or pulleys cut-off square with center line of belt. Re-adjust in affected area.
- Idler stands not centered on belt: readjust in affected area.
Cause and Remedy
- Insufficient traction between belt and pulley: lag drive pulley; increase belt wrap; install belt cleaning device.
- Pulley lagging worn: replace pulley lagging.
- Counterweight too light: add counterweight or increase screw take- up tension to value determined from calculations.
- Material spillage and build-up: improve loading and transfer condition; install cleaning devices, improve maintenance.
Cause and Remedy
- Insufficient traction between belt and pulley: lag drive pulley; increase belt wrap; install belt cleaning device.
- Counterweight too light: add counterweight or increase screw take- up tension to value determined from calculations.
- Pulley lagging worn: replace pulley lagging.
Cause and Remedy
- Improper belt installation causing apparent excessive belt stretch: pull belt through counterweight with tension equal to at least empty running tension; run belt in with mechanical fasteners.
- Improper initial positioning of counterweight in its carriage cause excessive belt stretch.
- Insufficient counterweight travel.
- Tension too high: increase speed; same tonnage; reduce friction with better maintenance and replacement of damaged idlers; decrease tension by increasing angle of wrap or install pulley lagging. Reduce CWT to minimum amount.
- Counterweight too heavy: lighten counterweight to value required by calculations.
- Insufficient belt tension: re-calculate belt tensions and select proper belt.
Cause and Remedy
- Skirt-board improperly adjusted or wrong material: adjust skirt-board supports to minimum 25mm between metal and belt with gap increasing in direction of belt travel; use skirting rubber (not old belt).
- Impact of material under loading area: install cushion idlers.
- Material hanging up in or under chute: improve loading to reduce spillage; install baffles; widen chute.
- Impact of material on belt: reduce impact by improving chute design; install impact idlers.
Cause and Remedy
- Dirty, stuck or misaligned return idler rolls: remove accumulations; install cleaning devices; use self cleaning return idler rolls; improve maintenance and lubrication.
- Cover quality too low: replace with belt of heavier cover gauge or higher quality rubber.
- Material spillage and build-up: improve loading and transfer condition; install cleaning devices, improve maintenance.
- Off center loading or poor loading: adjust chute to replace load on center of belt; discharge material in direction of belt travel at or near belt speed.
- Excessive sag between idlers causing load to work and shuffle on belt as it passes over idlers; increase tension if unnecessarily low; reduce idler spacing.
Cause and Remedy
- Sticking idlers: free idlers and improve maintenance and lubrication.
- Slippage on drive pulley: increase tension through screw take up or add counterweight; lag drive pulley; increase angle of wrap.
- Material spillage and build-up: improve loading and transfer condition; install cleaning devices, improve maintenance.
- Material trapped between belt and pulley: install plows or scrapers on return in front of tail pulley.
- Bolt heads protruding above lagging: tighten bolts; replace lagging; use vulcanized lagging.
- Excessive forward tilt of trough idler rolls: reduce forward tilt of idlers to no more than 2 from vertical.
Cause and Remedy
- Sticking idlers: free idlers and improve maintenance and lubrication.
- Material spillage and build-up: improve loading and transfer condition; install cleaning devices, improve maintenance.
- Slippage on drive pulley: increase tension through screw take up or add counterweight; lag drive pulley; increase angle of wrap.
- Pulley lagging worn: replace pulley lagging.
Cause and Remedy
- Heat or chemical damage: use belt designed for specific condition.
- Improper storage or handling.
Cause and Remedy
Spilled oil or grease: over lubrication of idlers; improve housekeeping; reduce quantity of grease used; check grease seals.
Cause and Remedy
- Fastener plates too long for pulley size: replace with smaller fasteners; increase pulley size.
- Wrong type of fasteners. Too tight or too loose: use proper fasteners and splice technique. Set up schedule for regular fasteners inspections.
- Tension too high: increase speed; same tonnage; reduce friction with better maintenance and replacement of damaged idlers; decrease tension by increasing angle of wrap or install pulley lagging. Reduce CWT to minimum amount.
- Heat or chemical damage: use belt designed for specific condition.
Cause and Remedy
- Belt improperly spliced: re-splice using proper method.
- Material spillage and build-up: improve loading and transfer condition; install cleaning devices, improve maintenance.
- Belt hitting structure: install training idlers on carrying and return run.
- Bowed belt: for new belt this condition should disappear during break-in, in rare instances belt must be straightened or replaced; check storage and handling of belt rolls.
Cause and Remedy
- Off center loading or poor loading: adjust chute to replace load on center of belt; discharge material in direction of belt travel at or near belt speed.
- Material spillage and build-up: improve loading and transfer condition; install cleaning devices, improve maintenance.
- Belt hitting structure: install training idlers on carrying and return run.
- Bowed belt: for new belt this condition should disappear during break-in, in rare instances belt must be straightened or replaced; check storage and handling of belt rolls.
Cause and Remedy
- Impact of material on belt: reduce impact by improving chute design; install impact idlers.
- Material trapped between belt and pulley: install plows or scrapers on return in front of tail pulley.
Cause and Remedy
- Insufficient transverse stiffness: replace with the proper belt.
- Pulleys too small: use larger diameter pulleys.
- Heat or chemical damage: use belt designed for specific condition.
Cause and Remedy
- Improper transition between troughed belt and terminal pulleys: adjust transition.
- Severe convex (hump) vertical curve: decrease idler spacing in curve; increase curve radius.
- Excessive forward tilt of trough idler rolls: reduce forward tilt of idlers to no more than 2 from vertical.
- Excess gap between idler rollers: replace with heavier belt.
- Insufficient transverse stiffness: replace with the proper belt.
Cause and Remedy
- Cuts on the belt cover. Punctures allow fines to penetrate between the cover and the carcass, causing damage. Make spot repairs with a vulcanizer or self curing repair material.
- Spilled oil or grease: over lubrication of idlers; improve housekeeping; reduce quantity of grease used; check grease seals.