The first useful inspection point is often the first return idler. If its shell has a wet band, material passed the head pulley and the cleaning station. Before buying another blade, trace the band back to the discharge chute. Is the primary cleaner touching the pulley-wrapped belt across its full width? Does the secondary cleaner have a firm belt surface behind it? Where does the removed material fall? Those observations explain more than a photograph of the pile beneath the conveyor.
This guide deals with hardware on the dirty face after discharge and with the plough that protects the clean face near the tail. The two faces have different jobs. A head-pulley cleaner strips carryback from the former carrying surface. A V-plough intercepts stray material on the inside of the return belt before it reaches a pulley nip. Calling both a “return scraper” can put the right component in the wrong place.
01. Where carryback shows up
Start at the discharge and follow the first marks, rather than beginning at the largest heap. On one line the earliest clue may be a damp crescent on the first return idler; the heap near the tail is merely where the residue finally let go. For close inspection, stop and isolate the conveyor. Mark the chute wall, first dirty idler and first floor deposit on a simple sketch. Those three marks locate the escape path.
The colour pattern is a useful sketch of contact. Brown at the shoulders means the outer strips escaped. Brown only in the middle calls for a look at the tip's centre and a straightedge over the isolated belt. Mark a splice and photograph it on both sides of the cleaner; photographs of unrelated belt sections can give the wrong answer.
| Finding | First place to inspect | Why it matters |
|---|---|---|
| Film just below the head pulley | Primary blade, pulley wrap and discharge path | The first stage is missing the adherent layer |
| Fine streaks after the secondary | Segment contact and belt support | The blade may be bridging a low spot |
| Material on the inside face near the tail | Loading spill, structure and V-plough | A return-side scraper on the dirty face cannot intercept it |
| Heavy deposits on one return idler | Cleaner leakage or local roller buildup | The growing shell can alter belt tracking |
A gouged cover traps material below the blade contact line. Inspect the damage at the loading zone as well as the cleaner; changing a tip cannot reach the bottom of a deep cut. The loading-zone discussion in our impact roller supplier guide is relevant when the scratches begin at one transfer.
02. Primary cleaner: pulley contact and blade form
At the head, the primary tip needs the pulley behind the belt. Look beneath the main discharge for a place where scrapings will fall clear. Centre the mounting sketch on the pulley, then apply the chosen cleaner's shaft dimensions. An offset measured from the chute wall cannot place the tip reliably on the pulley arc.
Urethane gives the primary a compliant working edge. If cargo from the head lands directly on that edge, however, the blade is being buried rather than cleaning. Check the actual trajectory under normal load. Leave enough bracket adjustment for the tip to wear; a spring already at its limit on a new installation is a bad sign.
Read the contact before turning the spring
The ridge against a used tip is an account of its contact. One end loaded and the other bare? Measure the belt position and shaft squareness. A broad, shiny contact patch can mean a folded tip. If slurry walks sideways, clear the pocket below the cleaner and sample the feed moisture before adding spring load. Keep the old setting in the log so the trial can be reversed.
03. Secondary cleaner: a supported finishing pass
The second blade deals with what survives the head-pulley pass. Place it near the point of departure or on a return span that has been deliberately supported. It needs a fall path for the fines and enough access to remove a segment. If the primary is missing, this finishing blade receives a bulk load it was not selected for; that can obscure the original failure.
Watch a loose return span as the splice passes. It may lift clear of a continuous tip, then slap back onto it. A hold-down or stabilizing roller can flatten a cupped or flapping belt, provided its position suits the cleaner drawing. Leave a way to clean the roller itself. Moving the blade to a convenient spot without a dribble chute may exchange carryback for spillage on the walkway.
| Stage | Normal contact area | Main task | Design question |
|---|---|---|---|
| Primary | Belt wrapped around head pulley | Remove most carryback | Can material fall into the discharge? |
| Secondary | Belt leaving pulley or a supported return span | Remove remaining film and fines | Will the belt stay flat across the blade? |
| Third stage if needed | Clear return span | Remove the remaining deposit | Provide a separate recovery path |
A service sheet that says 'spring moved 10 mm' is incomplete. Which arm, tip and shaft position produced that number? Record the component codes and the scale reading together. On the following shift, use the commissioning photograph to judge the used edge and any new mark on the cover.
04. Brush rolls: textured belts and loose fines
The dust is down in the shallow cover grain, below the straight scraper's edge. Try a brush with light enough contact that its filaments spring back after a pass. The maker sets the roll direction and speed. After a shift, check two places: the collector and the next return idler. Both tell you where the dust actually went.
Show the collector connection on the brush drawing. Without it, a brush may make the cover look clean while dust coats the rollers nearby. Clay in the filament roots is the opposite failure: pull a sample strip after the trial and see whether the bristles are already locked together.
A filament choice is also a cover choice
Ask which polymer the filaments actually are, together with its temperature and chemical limits. Wire needs a cover-contact trial if rubber is soft. For a chevron belt, include the cleat pitch and trough depth in the request; polishing the bar tops alone is not a useful result.
| Brush observation | Likely cause | First change to evaluate |
|---|---|---|
| Dust cloud around the roll | No effective capture or excessive agitation | Enclose and collect the discharge |
| Fine line left between bristle tracks | Worn strip or uneven mounting | Inspect the complete circumference |
| Material packed at the hub | Moisture or sticky fines | Reassess whether a brush suits this duty |
| Marks on the belt cover | Filament or interference too aggressive | Check material and working intrusion |
05. Air knives: cleaning without a contacting tip
Look for daylight between the nozzle and belt: that clearance is why an air knife has no contact wear. It may lift loose dry fines, provided the hood captures the cloud. Ask for both air volume and pressure at the proposed standoff, and for the compressor's operating cost. A number in bar alone cannot tell us what reaches the cover.
If the feed leaves a wet thumbprint on the belt, a stronger jet may produce more mist rather than a clean cover. Inspect the return after an ordinary shift. The cleaning methods and schedules guide treats the separate decision to wash it.
06. Ploughs and V-ploughs: protect the clean side
Think of the tail-pulley nip. A lump on the inner face of the return can be pulled into it. The V-plough upstream sends such lumps left and right; it has no reach around to the dirty outside face. Put collection space beside each wing so the protected pulley does not trade places with a buried stringer.
The plough drawing will say whether the blade floats or uses a set clearance. Check its travel and support against the installed splice. Observe the joint through a guarded view on the first run, and inspect for contact marks once the line is isolated.
| Device | Belt face | Where it belongs | Material it addresses |
|---|---|---|---|
| Primary scraper | Former carry face | Head-pulley face | Adhering bulk carryback |
| Secondary scraper | Former carry face | Leaving head pulley or supported return span | Residual film and fines |
| V-plough | Inside face | Return run before tail pulley | Stray lumps or spill approaching the nip |
07. Position relative to the head pulley
On a retrofit drawing, put the head-pulley centre and the belt departure tangent on paper first. Only then add the chosen shaft location. Some secondary units need to sit close to that tangent; a farther position may require a hold-down roller. Use the actual product dimensions. A tape reading from the chute wall can be precise and still describe the wrong origin.
Draw the discharge and the blade coming out of the frame, then add the snub pulley, first idler and awkward chute rib. Take the sketch to the steelwork. A beautifully aligned shaft is still a poor retrofit if the worn segment cannot get past the inspection door.
When a move downstream changes the job
A stopped belt can hide the movement that matters. If a dirty stripe appears at each splice passage, observe the run behind guarding and write down its timing. Isolate the line for close checks. Any new stabilizing roller needs access for shell cleaning as well as a place on the drawing.
08. Pressure, tensioner setting and blade wear
A tensioner has a short range of useful movement. A bent mainframe or cupped belt lies outside that range. Photograph the new blade beside its spring scale or torque mark at commissioning. At the next shutdown, compare that image with the used edge. The pair shows whether contact changed as the blade shortened.
Place the used tip against its spare and look along the edge. A shiny flat on a curled lip, despite a dirty belt, suggests too much contact. Alternating clean and dirty stripes suggest the edge is bouncing. Use the wear mark in this model's drawing to decide on replacement; the assumed fraction of a different blade's height has no standing here.
| Evidence at the station | What to verify | Action after verification |
|---|---|---|
| Continuous fine film | Blade contact, tensioner travel and belt support | Reset by maker's procedure or repair support |
| Wide polished cover band | Excess pressure, wrong angle or worn tip | Correct geometry before adding a new blade |
| Blade nearly at its wear line | Remaining adjustment and published limit | Replace and reset the tensioner |
| Tip chipped at one point | Splice strike, trapped lump or pulley defect | Remove the cause before replacing it |
09. Tip material and compatibility
Start with the splice and cover, then ask about blade hardness. A smooth vulcanized loop may accept a segment that a raised mechanical joint will strike. The maker's fastener rule is decisive, particularly for carbide. Include belt speed, actual temperature at the cleaner and the grit in the material sample with the request. A harder edge is only one of several changes, and often the wrong first one.
A step in the joint can announce itself once per revolution as a knock at the blade. Grit caught between soft polyurethane and a cut cover can leave a long score. Put the used blade beside the affected belt strip before ordering a replacement. The rubber conveyor belt cover grades guide is about cover choice; the cleaner supplier must still confirm its tip limits. Matching two Shore numbers, one from rubber and one from polyurethane, proves very little.
10. Cleaning hardware and belt tracking
Mark the belt-edge position under empty and normal load, then square the cleaner shaft to the observed path. A left-hand blade end worn short might follow a belt that wanders left; it might equally follow a skewed frame. The two measurements lead to different work orders.
Remove the first idler's paste jacket under isolation. Does the shell now rotate freely, and does the belt sit in the cleaner's intended band? The EP belt tracking guide addresses alignment elsewhere. Consider a self-aligning roller only after finding why the belt moved.
| Pattern | Check before moving the cleaner | Why |
|---|---|---|
| One blade end worn faster | Belt position, frame squareness and pulley lagging | Either belt wander or bracket skew can cause it |
| New drift after plough installation | Plough centring and material discharge | A one-sided obstruction can disturb the return |
| Drift follows a dirty roller | Roller shell buildup and bearing condition | The cleaner may be leaking upstream |
11. Sticky material and buildup
On wet feed, look below the tip for a clay roll that has nowhere to fall. As the pocket fills, the working edge lifts and the belt carries paste onward. Open the outlet and repeat the trial with similarly wet material. A dry start-up run will not reproduce it.
Pull apart the bristles after a wet-clay trial. If paste has set at their roots, a faster roll will remain clogged. Air may carry droplets rather than the solids. Try the primary and secondary with wet feed and an open chute. A chevron belt still leaves its recessed valleys beyond the reach of a straight blade.
At the first return idler, follow the paste trail toward the head. Did one band escape the scraper, or did spill drop onto the belt afterward? Clean the shell and separate that question from bearing sealing. The sealed conveyor roller guide deals with dust ingress into the bearing; its seal cannot remove an external jacket.
12. Discharge chute and cleaner interface
The cleaner needs somewhere to put what it removes. At the head, the primary should discharge with the main stream where the arrangement allows. A secondary farther along the return may need a dribble chute or collection tray. Follow the scraped material from the tip down to the outlet. Wet fines caught on a chute shelf can build back up to the blade and be carried away again. A cleaner fault may be a chute fault. Put an inspection opening where that pocket can actually be seen and reached for clearing.
Draw the old blade coming out of the station. That path needs room for the segment, tools and the released tensioner. It may not match a neat rectangular door on a general arrangement drawing. A compact unit and a long segmented one need different openings; measure the selected hardware before cutting steel.
| Chute finding | Consequence | Site check |
|---|---|---|
| Material shelf below the blade | Re-deposit or blocked cleaner | Observe the fall path and clean the pocket |
| Blade inside the main stream | Overloaded tip and inaccessible frame | Compare against the installation drawing |
| No recovery route for downstream cleaner | Spillage on walkway or structure | Add a dribble chute or collection system |
| Tensioner hidden behind steelwork | Missed service and poor adjustment | Check tool and blade-removal access |
13. Diagnose smearing, chatter and edge damage
Keep a card from the complaint: the deposit may dry to powder, remain claylike or leave grease. The sample helps choose which question to ask at the blade. Is the pocket below clear? Do the contact marks run its full width? A knock with every splice passage points to the joint; a chip at one end points to a local strike.
Put the original spring mark in the work order. Make one adjustment with the drive isolated, run the same load and inspect the marked belt section. If the team moves the arm and adds tension together, a cleaner result tells them very little about what fixed it.
| What the operator sees | Possible sources | First physical check |
|---|---|---|
| Wet stripe after cleaner | Missed contact, cupped belt or sticky film | Blade imprint and belt support |
| Chatter near every belt joint | Splice strike or insufficient damping | Joint profile and cleaner compatibility |
| Chatter at one speed | Resonance or unsupported return span | Frame stiffness and stabilizing roller |
| One edge frays | Mistracking, skew or fastener strike | Belt path and local tip damage |
| New blade wears rapidly | Grit trapped at tip or excessive contact | Residue sample and tensioner setting |
14. The blade inspection register
An ore conveyor that runs continuously should be checked before the spring reaches the end of its travel. A lightly used dry line may allow a longer gap. Note fresh piles on the walk-round; use the planned stop to measure remaining tip, spring position and any mark in the cover.
A repaired joint may strike an old blade setting even when the belt itself is the same. Watch the first controlled passes from behind guarding. At isolation, inspect the splice and mark the new contact position. Order spares against the mainframe and tensioner codes; appearance is a poor interchange guide.
A small register is enough
Use one row for each visit: hours, tip code, remaining height, tensioner scale, belt mark and action. Repeat a photograph from the same door. If the return is dirtier but the tip remains unworn, check wet feed and the chute shelf before changing compounds.
15. Before drilling a retrofit bracket
The retrofit drawing needs the obstructions as well as the new part. Mark the snub, first return idler, doors and cable tray around a ruler photograph of the pulley. Show the splice and the direction a worn blade must come out. Only then choose a frame that fits both the mounting and service envelope.
| Item to record | On-site evidence | Decision it supports |
|---|---|---|
| Pulley and belt geometry | Diameter, belt line and available bracket space | Primary model and mount coordinates |
| Splice and cover | Joint type, surface damage and thickness | Tip compatibility |
| Return support | Idler position, belt cupping and tension | Secondary position or hold-down need |
| Material path | Chute opening, shelf and collection route | Where removed material will go |
| Service route | Guarding, door and tool clearance | Whether blades can be safely replaced |
Put roller positions and joint type on the sketch. The splicing guide gives the relevant joint terms. SINOCONVE makes belts and supplies system components such as rollers and cleaners via qualified partners. The quote should identify each component's maker and specification.
16. A repeatable carryback check
Paint a measured patch upstream and another downstream of the station. Under isolation, collect the residue from each into separate weighed bags. Report the mass against the patch area, with throughput and moisture noted. Two patches farther along the same downstream run describe later shedding, rather than cleaning efficiency.
Mass on the cover is one line in the acceptance record. Add chute recovery, the coating on the first idler, tip wear after known run hours and cleanup time. Note rain or a change of feed beside the figures. The site's acceptable residue should be agreed before the trial; a single gram limit copied from another conveyor has no meaning here.
| Metric | Same-location method | What a change suggests |
|---|---|---|
| Residual mass per belt area | Defined sample area after cleaner | Direct comparison of surface carryback |
| Material in collection chute | Weigh or estimate per shift | Whether removed material is recovered |
| First-idler buildup | Photograph and measure shell deposits | Leakage reaching return components |
| Blade wear | Measure remaining usable height at fixed hours | Life of the selected tip and setting |
| Cleanup hours | Log the same return section | Operational cost of carryback |
17. Frequently asked questions
The primary bracket is marked 25 mm from a chute wall. Is that enough?
No. The bracket drawing must identify the pulley centre, the blade contact on its wrapped surface and the product trajectory. A distance from a random wall gives none of those coordinates.
A secondary blade leaves two outer stripes. Should it move downstream?
First check whether the return is cupped or bouncing at the present tip. Moving it may worsen contact. Gauge the span and ask whether a stabilizing roller fits the cleaner's installation drawing.
Can the spring mark from an old cleaner be reused?
Only if the blade, arm and tensioner are the same approved assembly. Otherwise the lever geometry changes the contact force. Start from the instructions for the installed model and record its measured setting.
The middle stays brown after scraping. What should I measure?
Compare the old tip's centre with its ends and put a straightedge over the stopped belt. A hollow belt, worn middle or deep cover scar can all leave a dirty stripe. Tightening the full blade risks scuffing shoulders that were already clean.
The dust sits below a textured cover. Will a blade reach it?
A straight edge may ride over the recesses. Trial a brush with the real dry feed, then inspect the filament roots and check where the loosened dust lands. Without a hood the apparent cure becomes an airborne dust problem.
Why is there a V-plough near the tail if the head has two cleaners?
Those head cleaners work on the former carrying surface. The V-plough intercepts stray lumps on the inside of the return before the tail nip. It needs its own discharge space on both sides.
The belt was replaced yesterday. Can the old cleaner setting stay?
Check the new splice as it passes the cleaner and mark the new belt line. Then set blade contact with the maker's method. A changed cover thickness or path can make the previous spring mark misleading.
Two samples were taken downstream. Do they show cleaner efficiency?
No. Those samples describe shedding between their two points. To compare cleaners, use equal upstream and downstream belt areas under similar feed. Also record how much material reached the collection chute.
