21948613 02 cb belt storage and handling

7/28/2019 21948613 02 CB Belt Storage and Handling

1/180

Total Service From - Scandura - Introduction

are and Maintenance

ntroduction

candura is committed to assuring total satisfaction with its conveyor belting, including th

chnical assistance to help you avoid problems and to help solve them when they arise.

ompt service is available from your Scandura distributor or your Scandura representativ

you are having problems, and cannot solve them with the help of this manual, call thecandura representative who calls on you.

nd there is help from the home office if a problem cannot be solved in the field. Scandur

pplication Engineers have many years of "hands-on" experience that is valuable for help

olve your belting problems. They are also experienced in the details of conveyor belt des

nd manufacture, so that a prompt, professional response is assured - including a trip to

our jobsite if required.

Copyright 2000 Scandura, Inc. All Rights Reserved

ttp://www.scandura.net/technical/document/Htm/introduction1.htm8/16/2004 10:28:54 AM

Index
http://www.scandura.net/technical/document/Htm/helpcontents1.htm


2/180

ystem Design and Belt Selection

are and Maintenance

ystem Design and Belt Selection

he same channels are open to you for system design and belt selection as are open for

oblem-solving. Your Scandura distributor or company representative is the best source

rn to for help. Here again, both have total company backup in case a situation requires

ome consultation.

addition, Scandura belting catalogs can help you make many belt selection decisions o

our own. Use our Market Alerts and Keypoints Specification Sheets to collect and organiz

e pertinent information you need to help solve your material hauling problems.


ttp://www.scandura.net/technical/document/Htm/systemdesignandbeltselection.htm8/16/2004 10:28:55 AM

Index


3/180

plicing

are and Maintenance

plicing

addition to Application Engineering Service, Scandura also offers a unique Field Splicin

ervice. Scandura's field splicing service offers technical assistance and training we will

ssist you in selecting a Scandura certified splicer, and provide personal supervision if

quired.

formation about this splicing service can be obtained through your local Scandura

presentative or by calling the company direct.


ttp://www.scandura.net/technical/document/Htm/splicing.htm8/16/2004 10:28:55 AM

Index


4/180

Count on Your Scandura Distributor

are and Maintenance

ount on Your Scandura Distributor

our Scandura distributor is very skilled in handling all your belting needs selection, car

nd maintenance and problem solving. Scandura keeps him abreast of the latest in conve

elting technology and problem solutions, so he is an expert. Count on him. And when a

oblem stumps the Scandura distributor experts, Scandura's technical resources arevailable to help out.

candura and its distributors are deeply committed to the kind of service that will give yo

e best value for your belting dollar. You can count on it!


ttp://www.scandura.net/technical/document/Htm/countonyourscanduradistributor.htm8/16/2004 10:28:56 AM

Index


5/180

Disclaimer

are and Maintenance

isclaimer

OTICE: Scandura, Inc, provides data and specifications, written and verbal, as a service

ur customers. As operating conditions and conveyor designs vary, system to system, no

presentation or warranty is made by Scandura, Inc. that the representative data and

pecifications provided herein are applicable to any individual system. Please contactcandura, Inc. for determination of data and specifications for specific applications and

esigns.


ttp://www.scandura.net/technical/document/Htm/disclaimer.htm8/16/2004 10:28:57 AM

Index


6/180

Basic Conveyor Belt Construction - Introduction

are and Maintenance

ntroduction

nderstanding how conveyor belts are made will help you to properly maintain and prote

our belting investment. It will also help you in selecting the best belt for your application

asically a conveyor belt consists of a reinforced member, or carcass, and protective cove



Index


7/180

Carcass Construction

are and Maintenance

arcass Construction

conveyor belt carcass can be made up of woven fabric, or steel cable. Scandura provide

de variety of weaves designed for specific applications.

he strength of a rubber belt can be increased by combining several plies of fabric in thenished carcass or by increasing the fabric strength in the same number of plies; a 3 ply,

10 pound fabric belt has a per inch of width rating of 330 pounds per inch width (P.I.W.)

hereas a 3 ply 150 pound fabric construction is 450 P.I.W. Each individual ply is covered

th rubber skim coats that are joined together under pressure. Following application of t

overs the entire unit is cured to form a lasting bond.

he quality of modern textiles, adhesives, and manufacturing techniques makes separatio

these elements virtually impossible. However, if the carcass is penetrated in operation,

oisture and/or abrasive materials can cause separation of the plies. Excessive wear on b

dges, which is usually the result of poor conveyor maintenance or improper belt training

n also initiate a ply separation.

onstructions are typically cut edge, - a development that has been made possible with

ewer adhesive systems and synthetic fabrics.

the Scandura line, Royalon and Usflex I are outstanding examples of rubber cut edge

elting. ATI is a PVC cut-edge belt. With Royalon or Usflex I you can take full advantage o

olume slab production, low manufacturing costs, and durable covers and carcasses. Usfl

is a rubber molded-edge belt, and Goldline HP is a PVC molded-edge belt.

candura belting is designed for strength, impact, and abrasion resistance. However, it ca

e damaged in several ways. Belt edges can rub against skirt boards or conveyor frames.

pilled material on the return side can damage pulleys, idlers, and belting. Tension settinat are too high or too low can also adversely affect belt performance.

ttp://www.scandura.net/technical/document/Htm/carcassconstruction.htm (1 of 2)8/16/2004 10:28:59 AM

Index


8/180

Carcass Construction

gure 1 A cross-sectional blueprint of a Scandura cut-edge Royalon belt.

eventive maintenance and regular inspections are the key to obtaining long, satisfactor

ervice from your Scandura conveyor or elevator belts.


ttp://www.scandura.net/technical/document/Htm/carcassconstruction.htm (2 of 2)8/16/2004 10:28:59 AM

Index


9/180

Belt Covers

are and Maintenance

elt Covers

he function of covers is to protect the carcass from impact, abrasion and environmental

ctors. As with carcasses, Scandura provides many cover compounds designed for differe

ervice applications.

selecting covers, temperature, speed, impact force, oil, chemical and loads must be

onsidered so that limitations of carcasses and covers are not exceeded.


ttp://www.scandura.net/technical/document/Htm/beltcovers.htm8/16/2004 10:29:00 AM

Index


10/180

torage, Handling, and Installing a New Belt

are and Maintenance

torage, Handling, and Installing a New Belt

ter the belt passes the manufacturing points of curing and inspection, it is wound on a 6

12" diameter steel, wood or compressed sawdust core with a square bar-hole. Heavy

auge polyethylene plastic is then wrapped around the roll and securely strapped to prev

amage during shipment.

gure 2 Scandura rubber belting is wound on a wood core with a square bar-hole.

ore:

elt Storage and Handling

nloading

e-Installation Checklist

nrolling

stalling the Belt


ttp://www.scandura.net/technical/document/Htm/storage.handling.andinstallinganewbelt.htm8/16/2004 10:29:01 AM

Index


11/180

Belt Storage and Handling

are and Maintenance

elt Storage and Handling

ou can assure successful installation of your belt by remembering these important facts:

q Check for any damage as soon as the belt is received.q Review the Packing List to be sure this is the belt you have ordered.q NEVER DROP THE BELTq Move belt by rolling (in the same direction as it was wound on core); moving on a

skid; or hoisting with a bar through the core and a spreader.q Store belt in a cool dry location with a temperature between 50F and 70F and a

relative humidity between 20% and 70%.q Leave belt packaging on belt as protection from oils, solvents, corrosive liquids,

ozone and sunlight.q Store belt in an upright position, preferably on a stand with each roll supported by

bar through its core. Prevent accidental rolling by blocking.


ttp://www.scandura.net/technical/document/Htm/beltstorageandhandling.htm8/16/2004 10:29:02 AM

Index


12/180

Unloading

are and Maintenance

nloading

onveyor belting should be handled very carefully during unloading. If it is dropped or

andled roughly, the protective package could break, causing the belt to unroll in a

lescoping twist. Once telescoping has occurred, rerolling properly is almost impossible.

oving the belt by rolling any great distance is not recommended. If it must be rolled, ro

e direction the belt is wound. Rolling belt in the opposite direction can cause it to loosen

nd telescope.

he preferred way to move a belt is with a hoisting bar and a sling or cables. If cables are

sed protect belt edges with special spreader bars or short wooden planks. A sling should

ever be used around the circumference of a roll of belting. Slings are very unstable and

use personal injury or belt damage.

void storing at temperature extremes. Even at temperatures a little below 40F rubber

ompounds can harden or stiffen. When put into use, the belt may take a while to adjust

e system. Belts with Neoprene covers are especially subject to stiffening at temperature

elow 40F. Prolonged mild temperatures are required to restore its flexibility.

temperatures over 90F for an extended period of time, belting can undergo softening

ging, and lowered impact resistance.

elting should be stored out of direct sunlight whenever possible. To minimize the possib

ozone attack, belt should be stored some distance from electric generators or arc weld

nused belt should be stored in its protective packaging until ready for use.


ttp://www.scandura.net/technical/document/Htm/unloading.htm8/16/2004 10:29:03 AM

Index


13/180

re-Installation Checklist

are and Maintenance

re-Installation Checklist

ior to installing the belt, be sure that pulleys, idlers, loading devices and other compone

e functioning properly.

Square up all pulleys.

Center and level all idlers in a straight line. Details for squaring idlers will be given late

Buildup, especially around idlers and pulleys should be cleared away.

Align the belt with the conveyor. Support belt weight and level the roll.

possible, mount belt on a stationary frame with a bar running through center. In this w

e belt will be stabilized for unrolling and threading. Good alignment is essential for good

acking onto the conveyor.


ttp://www.scandura.net/technical/document/Htm/pre.installationchecklist.htm8/16/2004 10:29:03 AM

Index


14/180

Unrolling

are and Maintenance

nrolling

eep solid discs in place while unrolling to help prevent telescoping.

though belting is usually rolled with the carrying side up, check to see if this is so.

herefore, if you are threading through the carrying side of the conveyor, the belt must lef the top of the roll. If you are threading through the return idlers, the carrying side mu

ad off the bottom.

eep the belt taut as you start unrolling, to help prevent telescoping. Ropes can be used

nub the roll so it does not overrun.

headroom is limited or if a frame and shaft cannot be used for unrolling, the belt can be

ulled off the roll and reefed. This is done by laying it in large loops to prevent strain. Be

reful not to kink or twist belt loops. The belt can also be mounted on a turntable with a

ertical spindle. In this case, be careful the edges are not damaged in the twist that will b

quired.


ttp://www.scandura.net/technical/document/Htm/unrolling.htm8/16/2004 10:29:04 AM

Index


15/180

nstalling the Belt

are and Maintenance

nstalling the Belt

efore the belt can be pulled around the conveyor some method must be used to fasten t

elt ends to the pulley mechanism (bulldozer or crane winch). The preferred method is

etal plates bolted to the belt end with a link for the pulling cable. Install 3/8" to 1/2"

ameter bolts, uniformly spaced, across the entire belt. If the belt is being pulled overoughing idlers, bolt the pulling plate to the bottom side of the belt. The bolted plate

ethod is much more preferred to cutting a single hole through the center of the belt or

otching the corners for the pulling rope or cable. If an old belt is being replaced it can be

t and attached to the lead end of the new belt, allowing the new one to follow as the ol

elt is pulled off. Bolting the trailing end of the old belt beneath the leading end of the ne

elt will make pulling smoother. Position personnel at conveyor key points to help avoid

ang-ups or belt damage.

gure 3 Threading a new belt onto a conveyor system.

owly pull the new belt into position. Overlap belt ends to required splicing length. Leave

bout 25 ft. of space between idlers (remove if necessary) to allow workspace for belt

plicing.

ttp://www.scandura.net/technical/document/Htm/installingthebelt.htm (1 of 2)8/16/2004 10:29:06 AM

Index


16/180

nstalling the Belt


ttp://www.scandura.net/technical/document/Htm/installingthebelt.htm (2 of 2)8/16/2004 10:29:06 AM

Index


17/180

Belt Splicing

are and Maintenance

elt Splicing

his section of the guide covers the essentials of mechanical and vulcanized splicing.

ore:

etting Up The Splicing Area

amping

eparing for the Splice

echanical Splices

ulcanized Splices

candura Field Splicing Services

hecklist For Maximum Splice Life


ttp://www.scandura.net/technical/document/Htm/beltsplicing.htm8/16/2004 10:29:07 AM

Index


18/180


are and Maintenance


is easier to splice on a horizontal portion of the conveyor than it is on an incline. If it m

e done on an incline, work at the lower end where the operation will be easier to perform

ome shelter should be provided to keep the work area dry. A permanent structure or amporary enclosure is the usual form of protection.

ter removing 25 to 30 feet of conveyor idlers, set up a table at the splicing site with

ccess to the work from both sides. If necessary, erect platforms to make the work

ccessible. Where the conveyor is too high to set up a splicing table, and more than one

plice is required, a splicing table can be set up on the ground, in line with the conveyor.

ach splice is completed the belt can be run onto this conveyor. Of course, the final splice

ll have to be made somewhere on the conveyor itself.

logistics call for installing several belts at one point and splicing them at another, sectio

n be joined with mechanical splices and pulled through. When the splice reaches the

plicing table, the mechanical fasteners are removed and the splice vulcanized.


ttp://www.scandura.net/technical/document/Htm/settingupthesplicingarea.htm8/16/2004 10:29:08 AM

Index


19/180

Clamping

are and Maintenance

lamping

verlapping belt ends should be tightly clamped so that belt ends will remain firmly in pla

though clamps can be made out of wood, plate steel clamps are much more effective.

o make this type of clamp, cut large rectangular pieces of steel to length. Bond pieces obber pulley lagging to the side that will contact the belt.

ace one clamp 3 to 4 ft. from end of the belt. Place the other clamp 10 to 12 ft. from th

her end. Secure one clamp to the conveyor frame, then draw the other one to it with ch

ocks to tighten the belt. Pull to remove the sag between the return idlers with the takeu

ulley in its proper position.


ttp://www.scandura.net/technical/document/Htm/clamping.htm8/16/2004 10:29:09 AM

Index


20/180

nstallation - Belt Splicing - Preparing for the Splice

are and Maintenance

reparing for the Splice

hese instructions apply to both mechanical and vulcanized splices.

q Be sure belt ends are in sound condition. If they are weak or oil-soaked, cut backuntil you find a strong, uncontaminated area.

q Draw proper centerlines. They are essential for a good splice.q The takeup pulley should be set to allow for the full amount of expected movemen

elongation, pulley travel in start and stop, and storage of spare belting.

he subject of takeups and takeup travel is covered elsewhere in this manual, but here is

elpful tip. If takeup movement cannot be maximized when several vulcanized splices are

e made, use of a mechanical fastener in the final splice will allow the belt to operate unt

as stretched enough for a vulcanized splice to be made.

gure 4 The takeup pulley.

ttp://www.scandura.net/technical/document/Htm/preparingforthesplice1.htm (1 of 2)8/16/2004 10:29:10 AM

Index


21/180

nstallation - Belt Splicing - Preparing for the Splice


ttp://www.scandura.net/technical/document/Htm/preparingforthesplice1.htm (2 of 2)8/16/2004 10:29:10 AM

Index


22/180

nstallation - Belt Splicing - Mechanical Splices

are and Maintenance

Mechanical Splices

echanical splices are most often used where takeup travel is limited, or where time does

ot permit vulcanization.

ore:electing the Right Fastener

stalling Fasteners

aximizing Fastener Efficiency

echanical Fastener Precautions


ttp://www.scandura.net/technical/document/Htm/mechanicalsplices1.htm8/16/2004 10:29:11 AM

Index


23/180

electing the Right Fastener

are and Maintenance

electing the Right Fastener

hoosing the right fastener calls for a study of various factors: Pulley diameter, belt

ickness, belt tension, loads, materials carried, startup voltage condition, frequency of

arting and stopping. Also, different types of fasteners are used for different types of bel

ook type fasteners are fine for lightweight carcasses, but bolt and rivet-type fasteners aeeded for heavier carcasses. In high tension applications, plate fasteners often work bes

nd in underground mining, interchangeable hinge fasteners are preferred.


ttp://www.scandura.net/technical/document/Htm/selectingtherightfastener.htm8/16/2004 10:29:12 AM

Index


24/180

nstalling Fasteners

are and Maintenance

nstalling Fasteners

or well-balanced bolt-type splices, start torquing bolts at the center of the splice and wo

ut. To obtain maximum splice efficiencies and to avoid damaging carcass fabrics, know a

et torquing limits in advance.

hen installation is complete, taper each corner of belt ends to prevent bulging that occu

the edge of the splice.


ttp://www.scandura.net/technical/document/Htm/installingfasteners.htm8/16/2004 10:29:13 AM

Index


25/180

Maximizing Fastener Efficiency

are and Maintenance

Maximizing Fastener Efficiency

here either belt cover is greater than 3/16", the cover can be cut away for countersinki

steners. Stresses on the cover and the fasteners are reduced. When either belt cover is

eater than 3/16", the fasteners should be countersunk to allow the fastener teeth deep

enetration into the carcass. Countersinking reduces wear of the fasteners and noise onturn idlers.


ttp://www.scandura.net/technical/document/Htm/maximizingfastenerefficiency.htm8/16/2004 10:29:14 AM

Index


26/180

Mechanical Fastener Precautions

are and Maintenance

Mechanical Fastener Precautions

heck mechanical fasteners often for wear or breakage. Where fasteners are missing, the

rain on the remaining fasteners may be too great to hold the splice together.

though a variety of fasteners may seem appropriate for your needs, be sure to check alternatives before making your selection. Consult fastener manufacturer's

commendations for the correct fastener for your application.


ttp://www.scandura.net/technical/document/Htm/mechanicalfastenerprecautions.htm8/16/2004 10:29:14 AM

Index


27/180

nstallation - Belt Splicing - Vulcanized Splices

are and Maintenance

ulcanized Splices

though making a vulcanized splice requires more time, skill and expense, it is far super

a mechanical splice in many regards. Compared to a mechanical splice, a vulcanized

plice:

q Is up to twice as efficient, and often lasts longer than mechanical splices.q Travels more smoothly and quietly over pulleys and idlers, with far less abrasion,

damage, and noise.q Has better resistance to localized strain.q Has better resistance to abrasion.q Resists harmful moisture and chemicals better.q Resists direct heat better, inasmuch as metal fasteners conduct heat to the carcas

to weaken fabric.

gure 5 Use only the best grade of splicing compounds such as Scandabond adhesive.

ore:

ulcanized Splicing Procedure


ttp://www.scandura.net/technical/document/Htm/vulcanizedsplices1.htm8/16/2004 10:29:16 AM

Index


28/180

Vulcanized Splicing Procedure

are and Maintenance

ulcanized Splicing Procedure

raftsmanship and care are the most important elements in a vulcanized splice. In cutting

e steps, for example, the fabric should not be cut below each step.

plice step lengths should never be shortened. And the fill-in fabric beneath the coverhould likewise never be short-cut. Either type of short-cutting will seriously reduce splice

e and strength.

se only the best grades of splicing compounds, compatible with the grades of splicing

aterials for the belt you are splicing. Do not use outdated materials. And do not skimp o

aterial. A proper buildup is essential for an effective cure.

oper tools and equipment are also vital for well executed splices. A prodder is the only

pe of tool that should be used for separating plies. Never use a screwdriver or a knife.

ake sure you have properly cooled your splice to 160F before opening the press. This w

inimize the possibility of cover or ply separation and blisters. The splice should be allow

cool completely before being put under tension.

gure 6 Carpenter's claw-type pincers are used for pulling away sections of belt cover anbric plies.

his procedure pertains to rubber belting. The procedure for splicing a Scandura PVC belt

corporates a finger method and requires different kits. Contact Scandura customer serv

r information on procedure and materials.

ttp://www.scandura.net/technical/document/Htm/vulcanizedsplicingprocedure.htm (1 of 2)8/16/2004 10:29:17 AM

Index


29/180

Vulcanized Splicing Procedure


ttp://www.scandura.net/technical/document/Htm/vulcanizedsplicingprocedure.htm (2 of 2)8/16/2004 10:29:17 AM

Index


30/180


are and Maintenance


you do not have your own tools and equipment, contact a professional splicer. Or ask

candura to recommend one. Scandura maintains a fulltime staff of professionals to help

stomers in the field.


ttp://www.scandura.net/technical/document/Htm/scandurafieldsplicingservices.htm8/16/2004 10:29:18 AM

Index


31/180

Checklist For Maximum Splice Life

are and Maintenance

hecklist For Maximum Splice Life

q See that skirting, plows and belt wipers touch splices lightly, if at all.q Because of their higher efficiency and safety factors, use vulcanized splices in

preference to mechanical fasteners wherever possible.q

Check splices regularly. Early detection of potential failure can save costly repairsand downtime later on. Conditions listed in the Problem Solving section of thismanual will help you to spot incipient trouble.

q When properly executed, and without accidental damage, a splice can be expectedlast through its design life.

q To minimize the number of splices, order the longest possible roll lengths. This wikeep splices and their problems to a minimum.

q If you have persistent trouble with splices, contact a reputable splicing firm, yourScandura distributor, or your Scandura representative.


ttp://www.scandura.net/technical/document/Htm/checklistformaximumsplicelife.htm8/16/2004 10:29:19 AM

Index


32/180

Belt Training

are and Maintenance

elt Training

ollowing the splice, the belt should be properly trained.

aining is the process of adjusting idlers, pulleys, and load conditions to ensure that the

elt does not run off center. Belts most always try to steer to the side of the idler it touchst.

hen a belt trains poorly, edges can be damaged and materials can spill with possible

amage to belts, idlers, and pulleys.

ore:

efore You Start Training:

our Pre-Training Checklist:

elt Training Procedure:

he Break-In Run

aining Devices

elt Training Problems and Solutions


ttp://www.scandura.net/technical/document/Htm/belttraining.htm8/16/2004 10:29:20 AM

Index


33/180

Before You Start Training:

are and Maintenance

efore You Start Training:

quare up and level the conveyor system. Be sure pulleys and idlers are square to the be

ath. You may have to move some idlers forward or backward in their mountings. If idler

e being mounted for the first time, lightly tighten bolts for the training for easy

djustment. Tighten when training is complete.


ttp://www.scandura.net/technical/document/Htm/beforeyoustarttraining..htm8/16/2004 10:29:20 AM

Index


34/180

Your Pre-Training Checklist:

are and Maintenance

our Pre-Training Checklist:

e sure to make these checks before belt startup:

q Has all splicing equipment been removed?q Are pulley shafts parallel to each other?q Were belt structure bolts checked for tightness?q Are belt idlers horizontal, in-line and square with conveyor centerline?q Have self-training idlers been installed properly?q Were belt idlers greased properly?q Is the reducer oil at the proper level?q Was the belt chain guard oiled?q Does the motor have proper rotation?q Were all tools, installation gear and foreign objects removed from area?q Was belt gravity takeup blocking removed?q Have belt wipers and skirting been properly adjusted?q Are pulleys and idlers free of material buildup?q Is the takeup carriage in good working order?q Will head and tail pulleys be watched for possible belt runoff?q ARE BELT EMERGENCY STOP CORDS INSTALLED?


ttp://www.scandura.net/technical/document/Htm/yourpre.trainingchecklist..htm8/16/2004 10:29:21 AM

Index


35/180

Belt Training Procedure:

are and Maintenance

elt Training Procedure:

q Always train a belt empty.q Shift only one idler at a time.q Pulleys should be kept square to belt travel.q

Jog belt for several revolutions while checking at head, drive, takeup, tail, and alocarry and return runs for smooth passage.q If everything is running smoothly, allow belt to run empty while continuing trainin

steps-

Start at head pulley and work toward tail on the return run.

Begin training 4 to 6 idlers before point of maximum runout.

Follow directions of belt travel while making corrective shifts.

Each idler shift should be very slight.

hen return run training is completed, begin training on the troughing side. Again, proce

the direction of belt travel and move idlers only slightly while making adjustments.

OTE: It is especially important that the belt be set to pass under the load point on-cente

nder all operating conditions. Belt will not train if it is loaded off-center.


ttp://www.scandura.net/technical/document/Htm/belttrainingprocedure..htm8/16/2004 10:29:22 AM

Index


36/180

The Break-In Run

are and Maintenance

he Break-In Run

Begin by loading lightly, and increasing gradually to full capacity.

If necessary re-align idlers (see installation steps).

Be sure belt chutes are loading belt on center.

Check to see that belt is still centered on tail pulley.

OTE: Where materials are loaded off-center, the belt can be forced out of alignment. Be

dges and conveyor parts can suffer severe damage if the condition continues.


ttp://www.scandura.net/technical/document/Htm/thebreak.inrun.htm8/16/2004 10:29:23 AM

Index


37/180

Training Devices

are and Maintenance

raining Devices

ost damage to belt edges occurs because the belt does not train properly. Reversible be

e hard to train. Short-centered wide belts run at slow speeds are hard to train, as are

elts that operate completely on flat-profile idlers. Training problems also arise with off-

enter loading or conveyor system misalignment. Even under normal operating conditionsaining devices must sometimes be installed to keep a belt running true.

gure 7 Belt edge damage due to poor training.

he types of devices discussed here are intended only to nudge the belt back on track if i

anders. If any of these devices are under constant stress from belt edges, the conveyor

ystem should be examined for possible misalignment of one or more elements. Without

ecaution, you will experience rapid wearout of the training device and excessive wear a

e belt edge.

ore:

elf-Aligning Idlers

ertical Edge Guides

orward-tilt Idlers

V"-Type Return Idlers

rowned Pulleys

ttp://www.scandura.net/technical/document/Htm/trainingdevices.htm (1 of 2)8/16/2004 10:29:24 AM

Index
http://www.scandura.net/technical/document/Htm/.v..typereturnidlers.htmhttp://www.scandura.net/technical/document/Htm/.v..typereturnidlers.htm


38/180

Training Devices


ttp://www.scandura.net/technical/document/Htm/trainingdevices.htm (2 of 2)8/16/2004 10:29:24 AM

Index


39/180

elf-Aligning Idlers

are and Maintenance

elf-Aligning Idlers

elf-aligning idlers (training idlers) are designed to move the belt back to the center whe

oves to one side or the other. Most of them work best in dry conditions. In wet conditio

here lower belt/idler friction can cause a belt to wander, self-aligning idlers with actuati

llers are highly effective.

ocation of self-aligning idlers is determined by belt width, speed and tension. At head an

il pulleys, they are especially helpful in keeping the belt on center. As a rule of thumb, s

gning idlers should not be installed any closer to a terminal pulley than the belt width in

ches changed to feet. For example, if belt width is 36 inches, do not install these idlers

oser than 36 feet from terminal pulley. On long-center conveyors they are often specifie

200-foot intervals. Self-aligning idlers are not ordinarily recommended for convex or

oncave curves. As stated earlier, self-aligning idlers are not intended to contact belt edg

ontinuously. If such a condition occurs, a more permanent solution should be found.


ttp://www.scandura.net/technical/document/Htm/self.aligningidlers.htm8/16/2004 10:29:25 AM

Index


40/180

Vertical Edge Guides

are and Maintenance

ertical Edge Guides

ertical edge guides are free-rolling cylinders placed in fixed brackets near the belt edge.

heir function is to contain the belt and prevent edge damage from contact with the

onveyor structure.

ertical edge guides are most often used on the return side of the belt, where the belt

sponds more easily to lateral pressure. In this application, guides are placed next to, an

ghtly ahead of return idlers, as well as along 50' to 100' centers. They are especially

fective for training assistance where disc-type return idlers are used.

though also designed for use on the troughing side, vertical edge guides in this position

xert less sideways pressure on the belt and are therefore minimally effective. And there

risk of snagging, if some part of the load comes in contact with the guide.

s with self-aligning idlers, vertical edge guides should make only occasional contact with

elt edges. If permanent misalignment, as indicated by continuous guide/belt contact, is

oblem, check the trouble-shooting chart in this guide. Early detection (and correction) o

is condition is essential for obtaining maximum service from training devices as well as

om your belting. Downtime, repairs and replacement costs will be minimized.


ttp://www.scandura.net/technical/document/Htm/verticaledgeguides.htm8/16/2004 10:29:26 AM

Index


41/180

orward-tilt Idlers

are and Maintenance

orward-tilt Idlers

aced under a belt, forward-tilt idlers help to prevent lateral belt movement. Some types

e pre-cast with a forward tilt, but most have to be tilted by shimming. If shimming is

quired, the shim is placed under the rear foot of the idler support, to tilt the idler in the

rection of belt travel. The top part of this roller should not move more than 1/8" to 3/8"rward. The forward tilt will amount to about 2. Greater tilt will result in excessive wear

e belt cover.


ttp://www.scandura.net/technical/document/Htm/forward.tiltidlers.htm8/16/2004 10:29:27 AM

Index
http://www.scandura.net/technical/document/Htm/.v..typereturnidlers.htmhttp://www.scandura.net/technical/document/Htm/helpcontents1.htm


42/180

Crowned Pulleys

are and Maintenance

rowned Pulleys

crowned pulley has a larger diameter at the center than at the ends. The crown should

pproximately 1/8" in diameter per foot of pulley width to a maximum total of 3/8". The

fect of this design is to direct the belt to the center of the pulley.

ver the years, changes in conveyor systems and belting designs have rendered crowned

ulleys less desirable for training control. The added stress at the center can cause belt

stortion and excessive strain.

here crowned pulleys may help are in low-tension applications with long, unsupported

pans. In these applications they may provide the only solution to training problems. Nev

se crowned pulleys when operating steel cord belting.


ttp://www.scandura.net/technical/document/Htm/crownedpulleys.htm8/16/2004 10:29:28 AM

Index
http://www.scandura.net/technical/document/Htm/.v..typereturnidlers.htmhttp://www.scandura.net/technical/document/Htm/helpcontents1.htm


43/180

Belt Training Problems and Solutions

are and Maintenance

elt Training Problems and Solutions

though many specific problems are addressed in the Problem Solving Chart in this manu

ere are a few detailed ways to correct major problems.

ne quick clue to whether the problem is in the system or in the belt is this:

the belt is running off only at one part of the structure, alignment can be suspected; if

elt runs off all along the structure, the belt or splices can be at fault.

ere are some specific problems and their solutions.

ore:

elt Curl

akeup Training Problems

eturn Side Training

aining New Or Used Belts


ttp://www.scandura.net/technical/document/Htm/belttrainingproblemsandsolutions.htm8/16/2004 10:29:28 AM

Index


44/180

Belt Curl

are and Maintenance

elt Curl

nce a belt begins to curl or cup, training becomes a real problem, especially on the retu

de of the conveyor. If the curl is caused by excessive oil or grease, the damaged section

hould be replaced.

nother short-term solution is to turn the belt over, but in the process you lose the

otective characteristics of the top cover. You also have the problem of increased materi

pillage and possible damage to vital conveyor parts.

ecause curl primarily affects training on the return side, here are two improvements:

Reeve the belt under every third or fourth return idler.

Lower belt tension.

he effect of these remedies is to provide better belt/idler contact, which leads to improv

aining.

s indicated above, turning the belt over will also provide some relief.


ttp://www.scandura.net/technical/document/Htm/beltcurl.htm8/16/2004 10:29:29 AM

Index


45/180

Takeup Training Problems

are and Maintenance

akeup Training Problems

ost belt training problems in the takeup area can be traced to the counterweight pulley.

nless it is kept aligned and stable at all times, the belt will not train properly and can be

everely damaged.

he solution: Yoking. Both horizontal and vertical counterweight pulleys should be yoked

eate a harness effect. And the carriage should move freely along the guides to avoid th

eezing or stalling action that can cause belt slippage.

n horizontal takeups the carriage can sometimes be derailed by accumulated debris or a

dden surge of power. Where these conditions are expected, restraining rails can be fitte

bove the flanged carriage wheels.

your takeup structure is exposed to wind, it is not practical to store long lengths of belt

thout some sort of protection. A wind shielding device will help prevent blowing of the b

gainst the conveyor.

takeup areas where long, unsupported lengths of belting can cause training problems,

se of crowned counterweight pulleys should be considered.


ttp://www.scandura.net/technical/document/Htm/takeuptrainingproblems.htm8/16/2004 10:29:30 AM

Index


46/180

Return Side Training

are and Maintenance

eturn Side Training

some underground mining operations, training on the return side has been improved b

Placing a 12" sleeve, 1/8" thick over the center area of the return idler.

Alternately advancing and raising each return roll.


ttp://www.scandura.net/technical/document/Htm/returnsidetraining.htm8/16/2004 10:29:31 AM

Index


47/180

Training New Or Used Belts

are and Maintenance

raining New Or Used Belts

ometimes a new belt will take a little while to settle in. The same is true of a used belt t

as been installed on a different conveyor. With the aid of mechanical training devices mo

elts perform satisfactorily.

aining problems are likely to remain stubborn in reversibles; belts on flat-profile idlers;

nd wide, short-centered belts that are running at low speeds. Because of the inherent

stability of these applications, training remedies may have to be improvised.


ttp://www.scandura.net/technical/document/Htm/trainingneworusedbelts.htm8/16/2004 10:29:31 AM

Index


48/180

reventative Care and Maintenance - Introduction

are and Maintenance

ntroduction

he major threats to long belt life are: material buildup on idlers and pulleys; material

pillage; loading impact; and training problems. The latter problem has already been dea

th. What follows is a discussion of how to minimize belt damage from the other conditio

ore:

ulley and Idler Maintenance

emoving Spilled Material

ombating Material Carryback

otecting Against Trapped Materials

nimizing Idler Junction Fatigue



Index


49/180


are and Maintenance


aterial buildup on pulleys and idlers can create serious training and damage problems.

ulley and idler surfaces should be cleaned as soon as buildup occurs. Here's why:

n the pulley and idler faces, material buildup can force the belt off-center, making it ridef the side of the pulley. When this happens, belt edges can be damaged by the conveyo

ructure. On high-tension or snubbed pulleys, buildup can weaken the belt in the area ov

e buildup, over a period of time.

aterial buildup is usually removed from pulleys and idlers by scraping. Care must be tak

ot to damage pulley or idler surfaces.

aterial buildup on pulleys can be controlled with scraper bars mounted near, but not

uching the pulley.

uildup on return idlers can be minimized by using disc-type return idlers, rubber-coated

lls, or solid-faced return rolls covered with rubber sleeves.

MPORTANT: Be sure conveyor is shut down when cleaning pulleys and idlers.


ttp://www.scandura.net/technical/document/Htm/pulleyandidlermaintenance.htm8/16/2004 10:29:34 AM

Index


50/180

Removing Spilled Material

are and Maintenance

emoving Spilled Material

pilled material can be a hazard for both idlers and belts. As it piles up it abrades idlers t

e point where the shell surface becomes rough enough to damage the belt. Spilled

aterials can also jam idlers and pulleys, which will increase drag.

gure 8 Hosing away spilled material.

ost spilled material can be shoveled or hosed away. If a shovel is used, care should be

ken not to damage the belt or conveyor parts. Spilled material should not be allowed to

ll on the return side of the belt. Since this material will then go through the tail pulley a

e entrapped. This causes localized tensions in the belt carcass which may lead to damag

nd shortened belt life.


ttp://www.scandura.net/technical/document/Htm/removingspilledmaterial.htm8/16/2004 10:29:35 AM

Index


51/180

Combating Material Carryback

are and Maintenance

ombating Material Carryback

hen material that clings to the top cover of the belt is carried to the return side, it build

p on idler rolls which leads to belt and idler damage. A number of cleaning systems are

vailable to minimize material carryback.

ore:

elt Wipers

ater Spray and Wiper Systems

ubber Pulley Lagging

ther Belt Cleaning Aids

he Belt Turnover System

r/Liquid Systems


ttp://www.scandura.net/technical/document/Htm/combatingmaterialcarryback.htm8/16/2004 10:29:36 AM

Index


52/180

Belt Wipers

are and Maintenance

elt Wipers

he most common method of removing built up material is some form of a belt wiper.

ocated past the discharge pulley, the belt wiper removes the material and allows it to fa

here it can be moved away from the conveyor.

typical setup is a strip of rubber mounted on a frame, positioned to make light contact

th the belt. The wiper should not touch the pulley and the mounting bracket should be

ept clear of the belt.

candura offers two kinds of belt wipers: the Uscothane Bead Bar Scraper and the

scothane 4281 Resistwear Scraper. Both are highly-efficient, long-wearing alternatives t

bber wipers. The Uscothane Bead Bar Scraper uses thousands of ultra-hard slippery bea

mbedded in the scraper edge of the bar.

gure 9 Conveyor belt scraper bar.

or especially sticky material, wiping is done with metal blades mounted on springs or

voted on weighted arms to maintain pressure. Check blade pressure often to protect co

om excessive abrasion. These should be used only if other types of wipers do not work.

ttp://www.scandura.net/technical/document/Htm/beltwipers.htm (1 of 2)8/16/2004 10:29:37 AM

Index


53/180

Belt Wipers


ttp://www.scandura.net/technical/document/Htm/beltwipers.htm (2 of 2)8/16/2004 10:29:37 AM

Index


54/180

Water Spray and Wiper Systems

are and Maintenance

Water Spray and Wiper Systems

here wipers alone are not totally effective in removing materials, a water spray system

n be added. Typically a wiper/spray system includes spray nozzles, a regulating valve,

ater control valve, drainage and a wiper blade.


ttp://www.scandura.net/technical/document/Htm/watersprayandwipersystems.htm8/16/2004 10:29:38 AM

Index


55/180

Rubber Pulley Lagging

are and Maintenance

ubber Pulley Lagging

heets of soft rubber applied to pulleys help to remove built up material as the belt passe

ver the pulley.


ttp://www.scandura.net/technical/document/Htm/rubberpulleylagging.htm8/16/2004 10:29:39 AM

Index


56/180

Other Belt Cleaning Aids

are and Maintenance

ther Belt Cleaning Aids

ower driven brushes and rubber spiral rolls have been offered as a solution to material

uildup. However, clogging is a problem, in terms of maintenance and belt abrasion. Belt

rrying dry materials can also be cleaned with compressed air.


ttp://www.scandura.net/technical/document/Htm/otherbeltcleaningaids.htm8/16/2004 10:29:39 AM

Index


57/180

The Belt Turnover System

are and Maintenance

he Belt Turnover System

ne of the most effective methods for dealing with the material carryback problems is to

stall a belt turnover system. As the belt makes its return run it is turned upside down, s

at built up material does not contact return idlers. This type of system has more than

paid its extra cost in most applications especially on long overland installations.


ttp://www.scandura.net/technical/document/Htm/thebeltturnoversystem.htm8/16/2004 10:29:40 AM

Index


58/180

Air/Liquid Systems

are and Maintenance

ir/Liquid Systems

here sticky materials are handled, the belt is given a film of water applied through an a

ompressor. Release agents can also be applied in this manner.


ttp://www.scandura.net/technical/document/Htm/air.liquidsystems.htm8/16/2004 10:29:41 AM

Index


59/180

rotecting Against Trapped Materials

are and Maintenance

rotecting Against Trapped Materials

hen lumps of hard materials are trapped between the belt and the pulley the stress is

ten great enough to rupture the fabric, and to damage the pulley.

enerally, material entrapment can be avoided by proper loading and by accurate beltaining. Even so, spills do occur and lumps of material do get onto the return side of the

elt. A number of devices are available to minimize the potential for damage from trappe

aterials.

ore:

ow Shaped Scrapers

rated Decking

ertical Screens

inged Pulleys


ttp://www.scandura.net/technical/document/Htm/protectingagainsttrappedmaterials.htm8/16/2004 10:29:42 AM

Index


60/180

low Shaped Scrapers

are and Maintenance

low Shaped Scrapers

ow shaped scrapers are often used to deflect lumpy materials from the path of the belt

e pulley. They can be installed singularly or in pairs at a 45 angle, or they can be

stalled in a "V" pattern. They are positioned above the belt, over the return side. In a

ertical takeup, a plow can also be used to deflect material away from the counterweightulley.


ttp://www.scandura.net/technical/document/Htm/plowshapedscrapers.htm8/16/2004 10:29:43 AM

Index


61/180

Grated Decking

are and Maintenance

rated Decking

ecking, placed between the carrying and return sides of the conveyor, catches all lumps

at may be spilled. It is primarily used in loading areas, but is more effective if used alon

e conveyor line.


ttp://www.scandura.net/technical/document/Htm/grateddecking.htm8/16/2004 10:29:43 AM

Index


62/180

Vertical Screens

are and Maintenance

ertical Screens

ertical screens in loading areas help to prevent material from spilling over onto the retur

de of the belt. They also shield personnel from being injured by the conveyor.


ttp://www.scandura.net/technical/document/Htm/verticalscreens.htm8/16/2004 10:29:44 AM

Index


63/180

Winged Pulleys

are and Maintenance

Winged Pulleys

here entrapment of material cannot be otherwise avoided, vaned or "winged" pulleys he

minimize belt damage. The slotted design permits large lumps to fall through the pulle

thout damage to the belt.

major disadvantage is the adverse effect the vanes have on splices, mechanical ones in

articular.

gure 10 A winged pulley can help prevent material entrapment.


ttp://www.scandura.net/technical/document/Htm/wingedpulleys.htm8/16/2004 10:29:46 AM

Index


64/180

Minimizing Idler Junction Fatigue

are and Maintenance

Minimizing Idler Junction Fatigue

ler junctions are points of major stress for a conveyor belt. And any of these junction

oblems can cause the belt breakdown problem known as idler junction fatigue: Wrong

ough angle; insufficient transition distance; varying idler heights; sharp curve radii; and

everal others that will be covered here.

ore:

ough Angle

ansition Distance

arying Troughing Idler Heights

onvex Curve Radii

ler Spacing

nction Gaps

ension

he Right Belt Construction


ttp://www.scandura.net/technical/document/Htm/minimizingidlerjunctionfatigue.htm8/16/2004 10:29:46 AM

Index


65/180

Trough Angle

are and Maintenance

rough Angle

he sharper the trough angle, the more belting is subject to longitudinal creasing and

exing. Minimize the trough angle whenever possible to avoid this cause of fatigue.


ttp://www.scandura.net/technical/document/Htm/troughangle.htm8/16/2004 10:29:47 AM

Index


66/180

Transition Distance

are and Maintenance

ransition Distance

lers must be spaced far enough apart that the belt will not be excessively stressed in

oing from flat to troughed travel, or the reverse. The stresses set up by too short a

ansition distance can dramatically shorten belt life. For a transition distance

commendation on a specific application, contact the Scandura Application Engineeringepartment.


ttp://www.scandura.net/technical/document/Htm/transitiondistance.htm8/16/2004 10:29:48 AM

Index


67/180

Varying Troughing Idler Heights

are and Maintenance

arying Troughing Idler Heights

hen an idler at a transition point is higher than an adjacent idler or pulley, the belt will f

xcessively at that point and fatigue the carcass.


ttp://www.scandura.net/technical/document/Htm/varyingtroughingidlerheights.htm8/16/2004 10:29:48 AM

Index


68/180

Convex Curve Radii

are and Maintenance

onvex Curve Radii

oo short a radius on a convex curve sets up fatigue potential that is similar to uneven

oughing idler heights. The curve arc should be as smooth and gradual as possible.


ttp://www.scandura.net/technical/document/Htm/convexcurveradii.htm8/16/2004 10:29:49 AM

Index


69/180

reventative Care and Maintenance - Minimizing Idler Junction Fatigue - Idler Spacing

are and Maintenance

dler Spacing

the belt creases at the junction, idlers may be too far apart. Fatigue can quickly occur.


ttp://www.scandura.net/technical/document/Htm/idlerspacing1.htm8/16/2004 10:29:50 AM

Index


70/180

unction Gaps

are and Maintenance

unction Gaps

though junction gaps have been pre-set, it is important to observe whether or not the b

being creased at these points. Too wide a gap between the center and edge rolls can

use belt jamming or pinching.


ttp://www.scandura.net/technical/document/Htm/junctiongaps.htm8/16/2004 10:29:51 AM

Index


71/180

Tension

are and Maintenance

ension

xcessive tension at curves and transition can cause belts to crease and fail prematurely.


ttp://www.scandura.net/technical/document/Htm/tension.htm8/16/2004 10:29:52 AM

Index


72/180

The Right Belt Construction

are and Maintenance

he Right Belt Construction

you are experiencing belt failure as a result of idler junction fatigue, the cause could als

e in the type of belt you are using. Be sure that the belt is able to support intended load

the idler junctions. A study of different belt specifications will provide you with the corr

ad-support information. Refer to Scandura catalogs for load support criteria.


ttp://www.scandura.net/technical/document/Htm/therightbeltconstruction.htm8/16/2004 10:29:53 AM

Index


73/180

Loading Area Precautions

are and Maintenance

oading Area Precautions

brasive action and load impact are greatest in the loading area. It is therefore important

inimize these effects for longer belt life.

rst, the location of the loading area should be set up past the tail pulley, with enough beea to be fully troughed before the load is accepted.

econd, in setting up the loading assembly, be sure that no part of it can ever come in

ontact with the belt (with the exception of the skirtboard rubber).

e sure to account for heavy vibration at the loading point that may cause lateral belt

ovements.

nce almost all top cover abrasion occurs at the loading point, it is to your advantage to

p the load for minimum wear in this area.

ttp://www.scandura.net/technical/document/Htm/loadingareaprecautions.htm (1 of 2)8/16/2004 10:29:55 AM

Index


74/180

Loading Area Precautions

gure 11 A proper loading area showing a skirting system and a loading chute.

ore:

oading Angle

peed of Loading

ull Loading vs. Partial Loading

eps to Minimize Impact Damage at the Loading Point


ttp://www.scandura.net/technical/document/Htm/loadingareaprecautions.htm (2 of 2)8/16/2004 10:29:55 AM

Index


75/180

Loading Angle

are and Maintenance

oading Angle

oad on the flat conveyor angle whenever possible. Loading on an incline increases

rbulence when material strikes the belt which results in premature belt wear.

the belt must slope, a short flat loading area ahead of the slope should be considered. sharp slope, loading should take place on an incline of less than 9, with a gradual curv

the belt to reach the desired angle. For minimum abrasion, loading in the direction the

elt is traveling is much to be preferred to loading from the side. Loading at an angle can

so push the belt to one side - damaging belt idlers and belt edges.


ttp://www.scandura.net/technical/document/Htm/loadingangle.htm8/16/2004 10:29:56 AM

Index


76/180

peed of Loading

are and Maintenance

peed of Loading

y to match your loading speed to the belt speed. When a slow-moving load hits a faster

oving belt, cover abrasion is much more severe than when both speeds are approximat

qual.

belt run at a relatively low speed is less susceptible to abrasion damage when it crosses

ver idlers.


ttp://www.scandura.net/technical/document/Htm/speedofloading.htm8/16/2004 10:29:56 AM

Index


77/180


are and Maintenance


slow-moving belt, fully loaded, can carry as many tons per hour as a faster-moving belt

artially loaded. And it is a lot easier on the belt. Very little more of the surface is expose

abrasion, and the potential for abrasion at the idlers is less.

opting for a higher loading at lower speeds, be sure not to exceed the operating tensio

n the belt. Operate only at or near the rated capacity of the belt.


ttp://www.scandura.net/technical/document/Htm/fullloadingvs.partialloading.htm8/16/2004 10:29:57 AM

Index


78/180

teps to Minimize Impact Damage at the Loading Point

are and Maintenance

teps to Minimize Impact Damage at the Loading Point

s with excessive abrasion, impact damage occurs most frequently in the loading area. T

eps that can reduce impact damage in this area are given below.

gure 12 Belt damage due to impact.

ore:

eight and Angle of Drop

pecial Idlers

ther Low Impact Feeders

eel Baffles

oad-Directing Skirt-Boarding

etermining Skirt-Board Length and Height

kirt-Board Installation Tips

hapers

kirting Rubber

stalling Skirting Rubber


ttp://www.scandura.net/technical/document/Htm/stepstominimizeimpactdamageattheloadingpoint.htm8/16/2004 10:29:58 AM

Index


79/180

Height and Angle of Drop

are and Maintenance

eight and Angle of Drop

he lower the drop and loading angle, the less danger of impact damage.

chute with a low angle helps to lower the impact of lumps. Too low an angle, however,

use material to clog. Straight steel chutes are usually more effective than curved chutepenings should be about 2/3 the width of the belt.

o further reduce the risk of lump damage, cut a rounded notch at the mouth of the chut

ner particles will drop on the belt first and cushion the shock of large particles and lump

e-cushioning the load against big-lump impact can also be accomplished with screens a

ates inserted in the chute ahead of the loading point.


ttp://www.scandura.net/technical/document/Htm/heightandangleofdrop.htm8/16/2004 10:29:59 AM

Index


80/180

pecial Idlers

are and Maintenance

pecial Idlers

oads should not be discharged onto steel idlers or pulleys because the continued impact

n soon damage a belt and the idlers. If heavy loads must be dropped onto idlers:

Replace metal idlers with rubber-cushioned impact idlers, or

Replace metal idlers with zero pressure rubber tires.

gure 13 Rubber-cushioned impact idlers.


ttp://www.scandura.net/technical/document/Htm/specialidlers.htm8/16/2004 10:30:01 AM

Index


81/180

Other Low Impact Feeders

are and Maintenance

ther Low Impact Feeders

he effect of high impact loading can also be softened by feeder belts and mechanical

eders. A feeder belt is higher in strength, and travels only a short distance. Although it

sed sacrificially, it is easier and cheaper to replace than the main belt.

he use of feeder belts for extremely punishing loading conditions is recommended. This

oncept employs a short length, extremely thick, belt located between the loading chute a

e main belt designed to withstand more damage and is easier and less costly to replace

an the main belt.

epending on the material handled, mechanical feeders can take the place of feeder belts

hese mechanical feeders are variously these types: Screw, apron, Ross, reciprocating pl

nd vibrating.


ttp://www.scandura.net/technical/document/Htm/otherlowimpactfeeders.htm8/16/2004 10:30:02 AM

Index


82/180

teel Baffles

are and Maintenance

teel Baffles

affles made of sheet iron or steel bars and hung inside the chute help to slow large lump

lling at great speed. Heavy chains are also suspended over chutes as a substitute for fix

affles.


ttp://www.scandura.net/technical/document/Htm/steelbaffles.htm8/16/2004 10:30:02 AM

Index


83/180

Load-Directing Skirt-Boarding

are and Maintenance

oad-Directing Skirt-Boarding

s material is being loaded onto a conveyor belt it must be contained long enough for the

ad to settle. Also, material must be kept from spilling over the belt edge. Skirt-boards a

esigned to handle both of these problems. Made of lengths of wood or metal, skirt board

elp to prevent spills and direct the load onto the belt.

though extremely useful, skirt-boards should be installed with care. If material lodges

nder a board it can quickly wear a belt cover away. Also, if a fatigued belt begins to turn

the edges it may contact the skirt-board and be damaged further.

gure 14 Load-directing skirt-board.


ttp://www.scandura.net/technical/document/Htm/load.directingskirt.boarding.htm8/16/2004 10:30:04 AM

Index


84/180

Determining Skirt-Board Length and Height

are and Maintenance

etermining Skirt-Board Length and Height

most applications, skirt-boards are required for only the distance it takes for a load to

ettle. In a horizontal loading, settling occurs about ten or fifteen feet past the loading po

he greater the incline the longer the load takes to settle. Simple observation will determ

e length of skirt-board required. In extreme cases, skirt-board may be required along tntire lengths of the belt to prevent spillage.

ne popular formula for determining the length of the skirt-board is to make it three or fo

mes the width of the belt. Another formula is that boards should be two to three feet in

ngth for every 100 FPM of belt speed. Experience will show which formula is best for yo

pplication.

he skirt-board should be high enough to contain the load at normal operating capacities

or belts, the height for 20 idlers is about 20% of the belt width. Height on conveyors w

5 and 45 idlers is about 1/3 of belt width. Loads that normally carry large quantities o

rge lumps may have to be higher.


ttp://www.scandura.net/technical/document/Htm/determiningskirt.boardlengthandheight.htm8/16/2004 10:30:04 AM

Index


85/180


are and Maintenance


kirt-boards should be installed high enough above the belt that they cannot possibly tou

e cover. They should taper up slightly so that material will not wedge under boards as t

ad moves along. Once you have determined the minimum height at which the board

nnot touch the belt under all operating conditions, taper the board upward.

hen fine material is being carried, a taper of 1/4" per foot of length is suggested. With

artially lumped material a taper of 1/2" is recommended.

egin the skirt-board installation at the loading chute with the ends set at about 2/3 of th

elt width. Fan them out so that the other ends widen to the belt edges.


ttp://www.scandura.net/technical/document/Htm/skirt.boardinstallationtips.htm8/16/2004 10:30:05 AM

Index


86/180

hapers

are and Maintenance

hapers

ood or metal wedges can be attached to the belt side of the skirt-board to direct large

mps onto the belt. Their service can be prolonged by the use of rubber covers. Shapers

hould not be installed directly opposite each other. It may be necessary to make several

djustments before the most effective placement can be determined.


ttp://www.scandura.net/technical/document/Htm/shapers.htm8/16/2004 10:30:06 AM

Index


87/180

kirting Rubber

are and Maintenance

kirting Rubber

kirting rubber is used to close the gap between the skirt-board and the conveyor belt. It

nctions are to help keep material from jamming under the board and to minimize spillag

fines.

though old pieces of belting have been used as skirting, the practice is not recommende

s fines accumulate in the belt fabric an abrasive action is set up that is very harmful to t

elt covers.

better method is to use solid rubber slabs that do not retain abrasive materials.

gure 15 Skirting rubber.

ttp://www.scandura.net/technical/document/Htm/skirtingrubber.htm (1 of 2)8/16/2004 10:30:08 AM

Index


88/180

kirting Rubber


ttp://www.scandura.net/technical/document/Htm/skirtingrubber.htm (2 of 2)8/16/2004 10:30:08 AM

Index


89/180

nstalling Skirting Rubber

are and Maintenance

nstalling Skirting Rubber

rill or punch elongated bolt holes in the rubber, so that the rubber slab can be adjusted

ownward as it wears against the belt.

he following chart shows the thickness of the rubber skirting recommended for variouspplications.

ype of Material Estimated Thickness of Rubber Skirting (ininches)

on-abrasive materials such as wood chips, flueust, loose cement or very fine coal.

3/16 - 1/4

Mildly abrasive materials such as sand, earth orituminous coal. Rock or coal under 3 in. size.

1/4 - 3/8

brasive materials such as anthracite coal, coker sinter. Overburden or coal up to 10 in. size.ron and copper ores or limestone under 9" inze.

1/2 - 5/8

eavy, sharp abrasive materials such as iron,opper, zinc, lead ores, and limestone trap rock,uartz, glass cullet, etc. Any hard, heavy, sharpre over 9 in. size.

5/8 - 3/4


ttp://www.scandura.net/technical/document/Htm/installingskirtingrubber.htm8/16/2004 10:30:09 AM

Index


90/180

Location and Operation of Takeups

are and Maintenance

ocation and Operation of Takeups

akeups perform a number of vital functions:

q They apply tension on the slack side of the drive pulley to help prevent drive slip.q They maintain tension under changing load and speed conditions.q They minimize belt sag between troughing idlers which reduces belt wear and pow

requirements.q They compensate for changes in tension as the belt stretches or shrinks in operati

he takeup area itself serves as a storage area for spare belting, convenient for

mergencies.

eally, the takeup is installed adjacent to the drive pulley. This is not always possible, as

e case with tail-end drives. In these instances, select the most accessible location forkeup service.

ore:

anual and Automatic Takeups

ensioning the Takeup

o Not Overtension!

lowable Takeup Movement


ttp://www.scandura.net/technical/document/Htm/locationandoperationoftakeups.htm8/16/2004 10:30:10 AM

Index


91/180

Manual and Automatic Takeups

are and Maintenance

Manual and Automatic Takeups

here are two type of takeups manually-adjusted and automatic. Manual takeups are

rewed or winched into a fixed position with static tension adjustments made as required

y hand. This type of takeup does not adapt as readily to changes in tension as an

utomatic one. However, they are often used on conveyors with short centers and in areahere space is limited, as in underground mining.

utomatic takeups are designed to equalize tension automatically as changes in tension

ccur. They can be of the horizontal or vertical type, with tension adjustments made by

ounter-weights or hydraulic devices.


ttp://www.scandura.net/technical/document/Htm/manualandautomatictakeups.htm8/16/2004 10:30:10 AM

Index


92/180

Tensioning the Takeup

are and Maintenance

ensioning the Takeup

he amount of takeup tension that will be required is determined by the location of the

keup assembly. The counterweight must apply the maximum static tension to prevent

ive slips and belt sag under all operating conditions. For most installations, the

ounterweight need only equal the combined tension of the carrying and return sides of telt.

here takeup travel is restricted, a double-reeved counterweight system can be installed

though it saves space it must now offset maximum belt tension in four belt positions an

oubles counterweight requirements.


ttp://www.scandura.net/technical/document/Htm/tensioningthetakeup.htm8/16/2004 10:30:11 AM

Index


93/180

Do Not Overtension!

are and Maintenance

o Not Overtension!

any takeup assembly, be careful not to overtension the belt. Overtension can fatigue

elts in marginal curves, pulleys and transitional locations: reduce belt/idler contact and

eate training and edge damage problems on the return side of the belt.


ttp://www.scandura.net/technical/document/Htm/donotovertension..htm8/16/2004 10:30:12 AM

Index


94/180

Allowable Takeup Movement

are and Maintenance

llowable Takeup Movement

he takeup pulley should move so that it does not strike its stops in any phase of belt

peration - loading, unloading, acceleration or deceleration. It should also be set to adjus

nticipated elongation and shrinkage of the belt under typical operating conditions. Consu

our Scandura representative for takeup position for a specific application.


ttp://www.scandura.net/technical/document/Htm/allowabletakeupmovement.htm8/16/2004 10:30:13 AM

Index


95/180

dlers

are and Maintenance

dlers

ore:

andard Troughing Idlers

ffset Idlers

eep Trough Idlers

atenary Idlers

eturn Idlers

ler Spacing

raduated Idler Spacing

ler Spacing on Convex Curvespacing on Concave Curves

lers at Transition Points

ler Care and Maintenance


ttp://www.scandura.net/technical/document/Htm/idlers.htm8/16/2004 10:30:14 AM

Index


96/180

tandard Troughing Idlers

are and Maintenance

tandard Troughing Idlers

andard troughing idlers have three rolls of equal length and diameter. They are usually

ounted at 20, 35 or 45 angles and roll on anti-friction bearings. Roll diameters vary

om 4" to 7". Diameters below 5" are generally used where lighter duty is evident or whe

earances are close. Larger diameters are usually required for heavier-duty applications.

he carrying capacity of a system can often be altered by changing the length of the cent

ll to widen or narrow the trough. Rolls of unequal length may also be specified, but only

ter the effects of this type of idler on material flow and belt performance have been

udied.


ttp://www.scandura.net/technical/document/Htm/standardtroughingidlers.htm8/16/2004 10:30:15 AM

Index


97/180

Offset Idlers

are and Maintenance

ffset Idlers

an offset idler, the center roll is positioned behind the concentrating rolls. The most

ommon use is in installations with minimal clearances. Offset idlers offer more protection

gainst idler junction fatigue than the inline type.

gure 16 Offset idler.


ttp://www.scandura.net/technical/document/Htm/offsetidlers.htm8/16/2004 10:30:16 AM

Index


98/180

Deep Trough Idlers

are and Maintenance

eep Trough Idlers

though 20 troughing idlers were once standard, angles of 35 and 45 are now more

ommonly in use. The benefits of deeper troughs, inline or offset, are:

21948613 02 cb belt storage and handling

Documents