dunlop conveyor belt design manual

Conveyor Belt Design Manual

INDEX

INTRODUCTION

Dunlop Africa Industrial Products is the leading designer and manufacturer of industrial rubber products in South Africa. In fact our belting

systems can be seen on some highly productive plants all around the globe.

What more can you expect, when you consider that our belts have been designed and fabricated by some of the best engineers in the

industry and from only the finest raw materials.

Using the most current technology, many components have taken years of refinement to attain such technological precision. And every belt

is guaranteed to provide maximum performance and maximum life.

DUNLOP BeltingPrint

Introduction

Dunlop Conveyor Belting Range

Belting Characteristics

Additional Features

SABS Specifications

Conveyor Belt Design

Step By Step Example of Belt Tension Calculation

Table 1: Table of Symbols

Table 2: Material Characteristics

Table 2(a): Typical Flowability

Determination of Conveyor Capacities

Table 3: Capacities of Troughed Belt Conveyors

Table 4: Recommended Maximum Belt Speed for Normal Use

Table 5: Recommended Idler Spacing

Table 6: Friction Factors

Table 7: Sag Factor

Table 7(a): Recommended Percentage Sag

Table 8: Estimated Belt Mass

Table 9: Typical Mass of Rotating Parts of Idlers

Table 10: Mass of Moving Parts

Table 11: Drive Factor

Conveyor Belt Selection

Table 12: Maximum Recommended Operating Tensions

Table 13: Recommended Minimum Pulley Diameters

Table 14: Load Support

Table 15: Maximum Number of Plies Recommended for Correct Empty Belt Troughing

Table 16: Carcass Thickness

Table 17: Mass of Belt Carcass

Table 18: Mass of Covers per mm of Thickness

Rate of Wear Graph

Table 19: Minimum Belt Top Cover Gauge Guide

Table 20: Belt Modulus

Tabulator Calculations

Sheet 1: Empty Belt

Sheet 2: Fully Loaded Belt

Sheet 3: Non-Declines Loaded

Sheet 4: Declines Loaded

Tension Tabulator

Vertical Curves

Maximum Incline Angle

Graph for Estimating Belt Length/Rolled Belt Diameter

Useful Data Conversion Factors

Conveyor Belting Design Manual

Page 1 of 33Dunlop Conveyor Belt Design Manual

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And with some 750 000 various specifications available, you can expect to find the right belt for your requirements no matter how

specialised.

This manual contains all the elements, formulae and tables you need to specify the exact belt. It has been compiled for your benefit, as a quick reference book for easy selection. If however you have an application not covered in the following pages, please contact Dunlop Africa

Industrial Products. A team of experienced and helpful engineers will be pleased to assist you.

Our range of excellent products, competitive pricing and impeccable service, has earned Dunlop Africa Industrial Products the reputation of

being the market's first choice.

DUNLOP CONVEYOR BELTING RANGE

Dunlop Africa Industrial Products manufactures the most comprehensive range of conveyor belting in South Africa.

Multi-ply rubber covered conveyor belting

z XT textile reinforced conveyor belting with grade N covers

z XT textile reinforced conveyor belting with grade M cut resistant covers

z Phoenix heat resistant belting

z Super Phoenix heat resistant belting

z Delta Hete heat resistant belting

z Fire resistant belting

z Rufftop belting

z Riffled concentrator belting

z Grey food belting

z Salmon pink food belting

z Endless belts

z Woodmaster

z Oil resistant belting

Solid woven PVC belting

z Standard solid woven PVC belting

z Nitrile covered PVC belting

Steelcord belting

z Fire resistant steelcord belting

z Steelcord reinforced conveyor belting with cut resistant type M covers

z Steelcord reinforced conveyor belting with type N covers

z Steelcord reinforced conveyor belting with "Ripstop" protection

z Steelcord reinforced conveyor belting with rip detection loops

Flinger belts



z High speed truly endless belting

BELTING CHARACTERISTICS

XT Rubber Conveyor Belting (conforms to SABS 1173-1977)

z From the early days of cotton duck plies, progress has been made in the manufacture of all-synthetic plies offering many advantages.

z The range of strengths has been greatly increased, with improvements in the flexible structure. The modern multi-ply belt is manufactured with a synthetic fibre carcass in a wide slab, then slit to width as required for individual orders.

z A wide range of belt specifications is available with current belt constructions having versatile applications.

z The standard XT belting (Grade N) incorporates covers suitable for the handling of most abrasive materials, having a blend of natural and synthetic rubber.

Cut resistant XT Rubber Belting

z Grade M Belts have covers with high natural rubber content recommended for belts operating under extremely arduous conditions where cutting and gouging of covers occurs.

Phoenix Heat Resistant Belting

z Phoenix Heat Resistant belting covers are styrene butadiene based and are recommended for belts handling materials with temperatures up to 1200C.

Super Phoenix Heat Resistant Belting

z Super Phoenix Heat Resistant belts have chlorobutyl covers and are recommended for belts handling materials with temperatures of up to 1700C.

Delta Hete Heat Resistant Belting

z Delta Hete heat resistant belting with EPDM synthetic rubber covers in a formulation developed to allow conveying materials of temperatures up to 2000C.

Fire Resistant Belting (conforms to SABS 971-1980)

z Fire Resistant XT belting is manufactured with covers containing neoprene and multi-ply carcass constructions to meet the stringent standards for safety in all underground mining industries and is therefore particularly suited to shaft applications.

Woodmaster

z This belt has been especially developed for the Timber Industry. The rubber has been compounded to provide resistance to oil and resin, and is non-staining.

Rufftop Belting

z This is a range of rough top package belting, of two or three ply all-synthetic carcass belts with deep impression rubber covers. The range is ideal for the packaging and warehousing industries and baggage handling installations such as airports and railway

stations etc.

Riffled Concentrator Belts

z Riffled conveyor belting has raised edges, is 1 500 mm wide and available in endless form. These belts are uniquely applied at gold mine concentrators.

Food Quality Belting

z Food quality belting is ideal where foodstuffs come into direct contact with the belt surface. This range of belting is manufactured from non-toxic materials and is resistant to oils, fats and staining, and meets the strict hygiene requirements laid down by the

food processing industry. The two types available are Grey food belting and Salmon pink belting



Endless Belting

z The complete XT range can be made available as factory spliced endless belts. These belts are recommended for short conveyor installations. (Suitable for lengths up to 50 in.)

Flinger Belts

z Flinger Belts are fitted to flinger conveyors, the primary function of which is to disperse the discharging material over a wide area, thus minimising heap build-up below the main conveyor. The flinging effect is achieved by running the flinger belt at a high speed

in a U configuration. Flinger belts are built and cured on a drum to eliminate a spliced join.

Solid Woven (PVC) Belting (conforms to SABS 971-1980)

z Commonly known as 'Vinyplast' solid woven PVC. The construction has inherently high fastener holding qualities. The belting is constructed of polyester and nylon with a cotton armouring, is impregnated with PVC and has PVC covers. These belts have been

specially developed to resist impact, tear, rot and abrasion and to meet the most stringent flame-resistant standards.

Nitrile Covered (PVC) Belting

z The nitrile cover on solid woven PVC belts is specially designed to meet the SABS specifications for use in mines, where a fire hazard exists. In general the nitrile cover has good flame-retardant properties and oil, abrasion and heat resistance.

Steelcord Belting (conforms to SABS 1366-1982)

z Steelcord conveyor belting is designed for very long hauls where textile reinforcement would either not achieve the requisite strength or would have too high an elongation at reference load. Resistance to severe shock and exceptional tensile loading is achieved by the wire reinforcement encased between thick top and bottom covers of the highest quality rubber. These belts are

designed to conform to or exceed the requirements of stringent standards and offer a long belt life.

Fire Resistant Steelcord Belting (Conforms to SABS 1366. 1982 type F).

z Steelcord belting of fire-resistant quality is made with specially compounded rubbers which render it self extinguishing. Fire-resistant steelcord belting offers great advantages in maintenance-free operation and long belt life for conveyors situated in fiery

mines.

Oil Resistant Belting

z Oil resistant belting provides easily cleanable covers of either nitrile or neoprene on all-synthetic fabric plies. Choice of covers gives maximum resistance to mineral and vegetable oils thus permitting the user to convey a wide variety of materials containing

mineral and vegetable oils.

ADDITIONAL FEATURES

1. Rip Protector

As an additional feature rip protection can be incorporated into the belt by means of arranging strong nylon fibres transversely or by inclusion of electronic loops. The textile rip protection can be built into the belt in 2-metre lengths at regular intervals or over

the full length of the belt.

2. Shuron Breaker Ply (XT belting)

For applications where the lump size of the material carried is large and where adverse loading conditions exist, an open weave

breaker ply can be incorporated below the top cover as an extra protection for the carcass.

3. Chevron Breaker (XT belting)

This incorporates steel tyre cord in a 'V shape, as a rip protection, at intervals over the belt length. Particularly recommended for

XT belting where arduous conditions are experienced i.e. slag transportation.

4. Belt Edges

Many conveyor belts track off at some stage of their lives, causing edge damage to a greater or lesser extent. Belts can be supplied with either slit or moulded edges.

Slit edges: All-synthetic constructed carcasses have good resistance to edge chafing, due to modern fibre construction In addition there is minimal penetration of moisture to the carcass and therefore no problem with carrying out hot vulcanised splices or repairs.



Moulded edges: A moulded rubber edge can be provided to protect the carcass from acids, chemicals and oils. In most applications a moulded

edge is unnecessary as synthetic fibres will not rot or be degraded by mildew.

SABS SPECIFICATIONS

Dunlop Africa Industrial Products conveyor belting complies with the stringent standards as laid down by the SABS.

1. SABS 1173-1977 - General purpose textile reinforced conveyor belting. 2. SABS 971-1980 - Fire-resistant textile reinforced conveyor belting. 3. SABS 1366-1 982- Steelcord reinforced conveyor belting.

The above specifications cover the requirements of the various conveyor belts and are classified according to the minimum full thickness

breaking strength of the finished belting in kilonewtons per metre width.

Further information regarding SABS specifications will be supplied on request.

CONVEYOR BELT DESIGN

Introduction

A conveyor belt comprises two main components:

1. Reinforcement or a carcass which provides the tensile strength of the belt, imparts rigidity for load support and provides a means

of joining the belt. 2. An elastometric cover which protects the carcass against damage from the material being conveyed and provides a satisfactory

surface for transmitting the drive power to the carcass.

In selecting the most suitable belt for a particular application, several factors have to be considered:

1. The tensile strength of the belt carcass must be adequate to transmit the power required in conveying the material over the

distance involved. 2. The belt carcass selected must have the characteristics necessary to:

a. provide load support for the duty. b. conform to the contour of the troughing idlers when empty, and c. flex satisfactorily around the pulleys used on the conveyor installation.

3. The quality and gauge of cover material must be suitable to withstand the physical and chemical effects of the material conveyed.

Belt Tensions

In order to calculate the maximum belt tension and hence the strength of belt that is required, it is first necessary to calculate the effective tension. This is the force required to move the conveyor and the load it is conveying at constant speed. Since the calculation of effective tension is based on a constant speed conveyor, the forces required to move the conveyor and material are only those to overcome frictional

resistance and gravitational force.

Mass of Moving Parts

For the sake of simplicity the conveyor is considered to be made up of interconnected unit length components all of equal mass. The mass of each of these units is called the mass of the moving parts and is calculated by adding the total mass of the belting, the rotating mass of all the carrying and return idlers and the rotating mass of all pulleys. This total is divided by the horizontal length of the conveyor to get the mean mass of all the components. At the outset the belt idlers and pulleys have not been selected and hence no mass for these components

can be determined. Therefore the mass of the moving parts is selected from the tabulated values to be found in Table 10.

Mass of the load per unit length

As is the case with the components the load that is conveyed is considered to be evenly distributed along the length of the conveyor. Given

the peak capacity in ton per hour the mass of the load per unit length is given by:

The effective tension is made up of 4 components

z The tension to move the empty belt Tx

z The tension to move the load horizontally Ty z The tension to raise or lower the load Tz z The tension to overcome the resistance of accessories Tu

Q = 0,278

or Q =

S 3,600S



The effective tension is the sum of these four components

Te = Tx + Ty + Tz +Tu

Tx = 9,8G x fx x Lc

Tz = 9,8Q x H

Various conveyor accessories that add resistance to belt movement are standard on most conveyors. The most common are skirtboards at

the loading point and belt scrapers. Other accessories include movable trippers and belt plows.

Tension required to overcome the resistance of skirtboards Tus

Tension to overcome the resistance of scrapers

Tuc = A x x fc

In the case of a belt plow the additional tension required to overcome the resistance of each plow is

Tup = 1,5W

Moving trippers require additional pulleys in the system and therefore add tension. If the mass of the additional pulleys has been included in the mass of moving parts then no additional tension is added. However, if a separate calculation of the tension to overcome the resistance

of the additional pulleys is required this can be determined for each additional pulley as follows

Corrected length Lc

Short conveyors require relatively more force to overcome frictional resistance than longer conveyors and therefore an adjustment is made to the length of the conveyor used in determining the effective tension. The adjusted length is always greater than the actual horizontal

length.

LC = L + 70

The length correction factor is

All conveyors require an additional tension in the belt to enable the drive pulley to transmit the effective tension into the belt without

slipping. This tension, termed the slack side tension T2, is induced by the take-up system. In the case of a simple horizontal conveyor the

maximum belt tension T1 is the sum of the effective tension Te and the slack side tension T2

ie: T1 = Te + T2

T1 is the tight side tension and 12 is the slack side tension

For a more complex conveyor profile that is inclined, additional tensions are induced due to the mass of the belt on the slope. This tension is

termed the slope tension 'h and increases the total tension.

Thus T1 = Te + T2 + Th

Tus = 9,8fs x Q x Ls

S x b

Tut = 0,01do x T1

Dt

C = Lc

L



The slack side tension is determined by consideration of two conditions that must be met in any conveyor. The first condition is that there must be sufficient tension on the slack side to prevent belt slip on the drive. The second condition is that there must be sufficient tension to

prevent excessive sag between the carrying idlers.

Minimum tension to prevent slip Tm

At the point of slipping the relationship between T1 and T2 is

Since T1 = Te + T2

is called the drive factor k. and the value of T2 that will just prevent slip is referred to as the minimum to prevent slip Tm and therefore

Tm = k x Te

Minimum tension to limit belt sag Ts

The tension required to limit sag is dependent on the combined mass of belt and load, the spacing of the carry idlers and the amount of sag

that is permissable.

Ts = 9,8Sf x (B + Q) x ld

The value of the slack side tension must ensure that both conditions are met and therefore T2 must be the larger of Tm or Ts.

Slope tension Th

The slope tension is the product of the belt weight and the vertical lift and has its maximum value at the highest point of the conveyor.

Th = 9,8B x H

Unit tension T

The maximum belt tension T1 has as its reference width the full width of the belt. Usually this is converted to the tension per unit of belt

width as this is the reference dimension for belt strengths.

Absorbed power

The amount of power required by the conveyor is by definition of power equal to the product of the force applied and the speed at which the

conveyor belt travels. The force applied is the effective tension and hence the power required at the shaft of the drive pulley/s is

P = Te x S

STEP BY STEP EXAMPLE OF BELT TENSION CALCULATION

As an example of the application of the formulae the belt tensions for the following conveyor will be determined:

T1 = e

T2

T2 = 1

Tee - 1

The expression 1

:e - 1

T = T1

W

Belt width 900 mm

Conveyor Length 250 m

Lift 20 m



Capacity 400 t/hr

Belt speed 1,4 m/s

Material conveyed ROM coal

Drive 210 degree wrap. Lagged drive pulley.

Take-up Gravity

Idler spacing 1,2 m

Idler roll diameter 127 mm

1. Determine mass of the load per unit length

Q = 0,278 S

= 0,278 x 400

1,4 = 79,4 kg/m

2. Look up the value of the mass of moving parts in Table 10. From the idler roll diameter and the nature of the material conveyed the application is considered as medium duty. For a 900 mm wide belt the mass of moving parts from Table 10 is 55 kg/m

3. Calculate the corrected length and the length correction factor.

LC = L + 70

= 250 + 70

= 320 m

C =LC

L

=320

250

= 1,28

4. Tension to move the empty belt.

TX = 9,8G x fX x LC

= 9,8 x 55 x 0,022 x 320

= 3794 N

5. Tension to move the load horizontally.

TX = 9,8Q x fY x LC

= 9,8 x 79,4 x 0,027 x 320

= 6723 N

6. Tension to lift the load.

TZ = 9,8Q x H

= 9,8 x 79,4 x 20

= 15562 N

7. No accessories are present and therefore the tension to overcome the resistance of accessories is zero.

8. Effective tension.

Te = TX + TY + TZ + TU

= 3794 + 6723 + 15562 + 0

= 26079 N

9. The absorbed power

P = Te x S

= 26079 x 1,4

= 36511W

10. The slack side tension. Slack side tension to prevent slip. The drive factor for 210 degree wrap and lagged pulley with a gravity take-up, as given in Table 11, is 0,38.

Slack side tension to limit sag to 2%. The sag factor for 2% sag is 6,3 and the estimated belt mass for a medium load and 900 mm belt width, as given in Table 8, is 11,1kg/m.

Tm = k x Te

= 0,38 x 36079

= 9910 N

TS = 9,8Sf (B + Q) x ld

= 9,8 x 6,3 x (11,1 + 79,4) x 1,2



TABLE 1 TABLE OF SYMBOLS

TABLE 2 MATERIAL CHARACTERISTICS

The required slack side tension is the larger of Tm or TS and hence

T2 = 9910 N

= 6705 N

11. Slope tension using the estimated belt mass found in Table 8 for medium load and 900 mm belt width is:

Th = 9,8B x H

= 9,8 x 11,1 x 20

= 2176 N

12. The maximum belt tension

The maximum belt tension is converted to the unit tension.

Effective tension.

T1 = Te + T2 + Th

= 26079 + 9910 + 2176

= 38165 N

T =T1

W

=38165

900

= 42,4 N/mm

= 42,4 kN/m

Symbols Description Unit

Symbol Description Unit

A Contact area of scraper blade m2 Sf Sag factor

B Belt mass per unit length kg/m T Unit tension kN/m

b Width between skirtplates m T1 Maximum belt tension across full belt width N

Bc Edge Distance mm T2 Slack side tension N

C Length correction coefficient Te Effective tension N

D Material Density kg/m3 Th Slope tension N

Dt Diameter of pulley t mm Tm Minimum tension to prevent slip N

do Diameter of pulley bearings mm Ts Minimum tension to limit sag N

fc Friction coefficient for scrapers Tu Tension induced in overcoming resistance of accessories N

fs Friction coefficient for skirtboards Tuc Tension to overcome resistance of scrapers N

fx Friction coefficient for empty belt Tus Tension to overcome resistance of skirtboards N

fy Friction coefficient for loaded belt Tx Tension to move the empty belt N

G Mass of moving parts kg/m Ty Tension to move the load horizontally N

H Change in elevation along conveyor length m Tz Tension to lift (or lower) the load N

ld Idler spacing (carry idlers) m W Belt width mm

k Drive factor Coefficient of friction between belt and drive pulley

L Horizontal length of conveyor m Angle of wrap on the drive radians radians

Lc Corrected length of conveyor m Pressure of scraper on the belt N/m2

Ls Length of skirtboard m Belt capacity expressed in ton per hour t/hr

P Absorbed power W Trough angle degree

Q Mass of load per unit length kg/m Material surcharge angle degree

S Belt Speed m/s

Material CharacteristicsSuggested

Grade

Bulk Density (t/m3)

Angle of Surcharge (degrees)

Max. Rec. Conv. Slope (degrees)


24/05/2004

Acid phosphate MA N 0,96 10 13

Alum NA N 0,80 25 22

Alumina MA N 0,90 10 12

Aluminium sulphate NA N 0,90 20 17

Ammonium chloride MA N 0,80 10 10

Ammonium nitrate MA N 0,70 25 23

Ammonium sulphate, granular MA N 0,80 10 10

Asbestos ore or rock VA N/M 1,30 20 18

Asbestos shred MA N 0,37 30 30

Ashes, coal, dry MA N 0,60 25 23

Ashes, coal, wet MA N 0,75 25 25

Ashes, fly MA N 0,70 30 23

Ashes, gas producer, wet MA N 1,20 30 28

Asphalt NA N 1,30 30 30

Bagasse NA N/PHR 0,13 30 30

Bark, wood, refuse NA N 0,24 30 27

Barley NA N/GF 0,60 10 12

Barytes, powdered MA N 2,10 10 15

Bauxite, ground, dry VA N/M 1,10 20 18

Bauxite, mine run VA N/M 1,36 20 17

Bauxite, crushed, 75mm VA N/M 1,30 20 20

Beans NA N/GF 0,70 5 7

Beet, pulp, dry NA N/GF 0,22 30 25

Beet, pulp, wet NA N/GF 0,60 30 25

Beets, whole NA N/GF 0,76 20 20

Borax MA N 0,90 20 20

Bran NA N/GF 0,30 10 12

Brewers grain, spent, dry NA N/GF 0,45 30 27

Brewers grain, spent, wet NA N/GF 0,90 30 27

Brick VA N/M 1,76 30 27

Calcium carbide MA N 1,20 20 18

Carbon black, pelletised MA N 0,35 5 5

Carborundum 75mm VA N/M 1,60 10 15

Cashew nuts MA N/GF 0,56 30 22

Cement, portland NA N/PHR 1,50 25 20

Cement, portland, aerated NA N/PHR 1,06 5 10

Cement clinker MA N/DHR 1,36 25 18

Chalk, lumpy MA N 1,30 10 15

Chalk, 100 mesh and under MA N 1,10 25 28

Charcoal MA N 0,35 25 22

Chrome ore HA/S N 2,10 10 17

Cinders, blast furnace MA N/M 0,90 10 18

Cinder, coal MA N 0,65 20 20

Clay, calcined MA N 1,44 25 22

Clay, dry, fines MA N 1,76 20 22

Clay, dry, lumpy VA N 1,10 20 20

Coal, anthracite, 3mm and under NA N/PVC 0,96 20 18

Coal, anthracite, sized NA N/PVC 0,90 10 16

Coal, bituminous, mined 50 mesh and under NA N/PVC 0,83 30 24

Coal, bituminous, mined and sized NA N/PVC 0,80 20 16

Coal, bituminous, mined, run of mine MA N/PVC 0,90 25 18

Coal, bituminous, mined, slack 12mm and under MA N/PVC 0,75 25 22

Coal, lignite MA N/PVC 0,75 25 22

Cocoa beans NA N/GF 0,56 10 12

Coke, loose VA N/M 0,48 30 18

Coke, petroleum, calcined VA N/M 0,64 20 20



Coke, breeze, 6mm and under VA N/M 0,48 20 22

Concrete, 100mm lumps VA N/M 2,10 10 18

Concrete wet VA N/M 2,20 24 18

Copper ore VA N/M 2,17 20 20

Copper sulphate VA N/M 1,30 20 17

Corn, ear NA N/GF 0,90 25 18

Corn, shelled NA N/GF 0,70 10 10

Cornmeal NA N/GF 0,65 20 22

Cottonseed cake NA N/GF 0,67 20 20

Gullet HA/S M 1,60 20 20

Dolomite VA N/M 1,60 18 20

Earth, as dug, dry VA N/M 1,20 20 20

Earth, wet, with clay MA N 1,70 30 23

Feldspar VA N/M 1,44 25 17

Flaxseed MA O 0,70 10 12

Flour, wheat NA N/GF 0,60 30 21

Fluorspar MA N 1,70 30 20

Foundry sand, old sand cores etc. VA M/PHR 1,36 25 20

Fullers earth, dry MA N 0,50 10 15

Fullers earth, oily MA O 1,00 20 20

Glass batch HA/S M 1,44 10 22

Grain, distillery, spent dry NA N/GF 0,48 10 15

Granite, broken, 75mm lumps VA N/M 1,44 10 18

Graphite, flake NA N 0,65 10 15

Gravel, bank run VA N/M 1,52 25 20

Gravel, dry, sharp VA N/M 1,52 20 16

Gravel, pebbles VA N/M 1,52 10 12

Gypsum, dust, not-aerated MA N 1,50 20 20

Gypsum, dust, aerated MA N 1,04 30 23

Gypsum, 12mm screened MA N 1,20 25 21

Gypsum, 75mm lumps MA N 1,20 10 15

Illmenite ore MA N 2,40 10 18

Iron ore, coarse crushed VA N/M 3,00 20 18

Iron ore, crushed fine VA N/M 3,50 20 18

Kaolin clay, 75mm and under MA N 1,00 20 19

Lead ores MA N 3,80 10 15

Lead oxide, heavy MA N 2,40 25 20

Lead oxide, light MA N 1,20 25 20

Lignite, air dried MA N 0,80 10 18

Lime, ground, 3mm and under NA N 1,00 30 23

Lime, hydrated NA N 0,60 25 21

Lime, pebble MA N 0,90 10 17

Limestone, agricultural 3mm and under MA N 1,10 10 20

Limestone, crushed MA N 1,40 25 18

Linseed cake NA OR/PVC 0,80 20 15

Linseed meal NA OR/PVC 0,43 20 20

Litharge, pulverized (lead oxide) MA N 3,60 10 15

Magnesium chloride MA N 0,53 30 23

Magnesium sulphate MA N 1,10 10 15

Manganese ore VA N/M 2,15 25 20



Manganese sulphate MA N 1,10 10 15

Marble, crushed 12mm and under VA N/M 1,40 10 15

Mica, ground MA N 0,22 20 23

Mica, pulverized MA N 0,22 10 15

Mica, flakes MA N 0,32 5 8

Molybdenite, powdered MA N 1,70 20 25

Mortar, wet VA N/M 2,20 24 18

Nickel-cobalt VA N/M 1,80 10 20

Oats NA GF/PVC 0,42 10 10

Peanuts in shells NA N 0,27 10 8

Peanuts, shelled NA GF/PVC 0,65 10 8

Peas, dried NA GF/PVC 0,75 5 8

Phosphate, triple super ground fertilizer MA N/OR/PVC 0,80 20 18

Phosphate rock, broken, dry VA N/M 2,00 20 18

Phosphate rock, pulverized VA N/M 2,10 25 18

Potash ore MA N 1,30 10 15

Pumice, 3 mm and under MA N 0,67 30 22

Pyrites, iron, 50 - 75mm in lumps VA N/M 2,25 20 17

Pyrites, pellets VA N/M 2,00 10 15

Quartz HA/S N/M 1,36 10 15

Rice NA GF/PVC 0,65 5 8

Rock, crushed HA/S N/M 2,15 20 18

Rubber, pelletised MA N 0,80 20 22

Rubber, reclaim NA N 0,45 20 18

Rye NA GF/PVC 0,70 10 8

Salt, common dry, coarse MA N/GF/PVC 0,75 10 20

Salt, common dry, fine MA GF/PVC 1,20 10 11

Sand, bank, damp VA N/M 1,90 30 22

Sand, bank, dry VA N/M 1,60 20 18

Sand, foundry, prepared VA N/M 1,36 30 24

Sand, foundry, shakeout VA N/M/PHR 1,50 25 22

Sand, Silica, dry VA N/M 1,50 10 12

Sand, core VA N/M 1,04 25 26

Sandstone, broken VA N/M 1,44 20 20

Sawdust NA N/OR/PVC/W 0,20 25 22

Shale, broken MA N 1,50 10 18

Shale, crushed MA N 1,40 25 22

Sinter VA N/M/PHR 1,80 10 15

Slag, blast furnace, crushed VA M/PHR/DHR 1,36 10 10

Slag, furnace, granular, dry VA M/PHR/DHR 1,00 10 15

Slag, furnace, granular, wet VA N/M 1,50 30 22

Slate MA N 1,36 20 18

Soap, beads or granules NA N/PVC 0,32 10 12

Soap, chips NA N/PVC 0,32 10 18

Soda ash, briquettes MA N 0,80 10 7

Soda ash, heavy MA N 0,96 20 18

Soda ash, light MA N 0,43 25 22

Sodium nitrate MA N 1,20 10 11

Sodium phosphate MA N 0,90 10 16

Soyabeans, cracked NA GF/PVC 0,56 20 18



Characteristics

Cover Grade

TABLE 2(a) TYPICAL FLOWABILITY

Determination of Conveyor Capacities

The capacity of a troughed belt is a function of:

1. The cross sectional area of the load which can be carried without spillage. 2. The belt speed. 3. The material density.

The cross sectional area is influenced by many factors including the flowability of the material, the angle of surcharge and the incline angle

Soyabeans, whole NA GF/PVC 0,77 10 14

Starch NA GF 0,60 10 12

Steel trimmings HA/S M 2,40 20 18

Sugar, granulated NA GF 0,83 10 15

Sugar, raw, cane MA N 0,96 20 22

Sulphate powdered MA N 0,90 10 21

Talc, powdered NA N 0,90 10 12

Titanium ore VA N/M 2,40 10 18

Titanium sponge MA N 1,04 30 25

Traprock VA N/M 1,60 20 18

Triple super phosphate MA N/OR/PVC 0,80 20 18

Vermiculite, expanded MA N 0,25 20 23

Vermiculite, ore MA N 1,20 20 20

Walnut shells, crushed NA GF 0,65 20 20

Wheat NA N/GF/PVC 0,77 10 12

Woodchips NA OR/W 0,32 30 27

Zinc ore, crushed HA/S M 2,60 25 22

Zinc ore, roasted HA/S SPHR/DHR 1,76 25 25

Key: HA/S - Highly abrasive/sharp

MA - Mildly abrasive

NA - Non-abrasive

VA - Very abrasive

Code: N - SASS 1173 NH polyisoprine

M - Higher natural rubber content SASS 1173

OR - Oil resistant

GF - Grey Food

PHR - Phoenix Heat Resistant

SPHR - Super Phoenix heat resistant

W - Wood master

DHR - Delta Hete heat resistant

PVC - Polyvinylchloride

FR - Fire resistant SASS 971

Angle of Surcharge

Angle of Repose

Material Characteristics

5 0 - 19 Uniform Size

10 20 - 29 Rounded, dry ,medium weight

20 30 - 34 Granular lumpy (Coal, Clay)

25 35 - 39 Coal, stone, ores

30 40 - 45 Irregular (wood chips)



at the load point of the conveyor. To achieve optimum load area the loading chutes must be designed to ensure the most advantageous

initial load shape and this can only be achieved if:

1. The load is placed centrally on the belt. 2. The material is delivered in the direction of belt travel and at a speed approaching that of the belt. 3. The angle of incline at the load area must be less than 1 ~O,

To ensure that the optimum load shape is maintained along the entire belt length:

1. The idler pitch should be such as to limit sag to acceptable levels. 2. The belt must be trained properly. 3. The lump size in relation to belt width must be within the recommended limits. 4. The belt must give adequate support to the load.

Under ideal conditions the cross sectional load area is:

At = (Ab + As) / 106

Where

Ab = (0,371W + 6,3 + M x cos) (M x sin)

M = 0,3145W - 3,2 - Bc

W - Belt width (mm)

Bc- Edge distance (mm)

- Iroughing angle (degree) - Material surcharge angle (degree) At - Cross sectional load area (m2)

The belt capacity in ton/hour is

Capacity = 3,6At x D x S

Where

D - Material Density (kg/m3)

S - Belt speed (m/s)

TABLE 3 CAPACITIES OF TROUGHED BELT CONVEYORS IN TON/HOUR

As = (0,186W + 3,2 + M x cos )2 ( - sin2 )sin 180 2

Belt Width mm

Recommended Max. Lump Size Trough

Angle Degrees

Area of Load

m2

Speed m/s

Sized mm

Unsized mm

0,5 0,8 1,2 1,6 2,0 2,5 3,0

600 125 200 20 0,033 59 95 142 190 236 297 357

27 0,037 66 106 160 213 266 333 400

30 0,038 69 110 164 218 274 342 410

35 0,040 72 115 173 230 288 360 432

45 0,042 76 121 181 242 303 378 436

750 150 250 20 0,054 97 156 233 311 389 486 583

27 0,060 109 173 259 346 432 540 648

30 0,062 112 179 268 357 446 558 670

35 0,065 117 187 281 375 468 585 702

45 0,068 122 196 294 392 490 612 734

900 175 300 20 0,080 144 230 346 461 576 720 864



TABLE 4 RECOMMENDED MAXIMUM BELT SPEEDS FOR NORMAL USE (METRES PER SECOND)*

27 0,090 162 259 389 518 648 810 972

30 0,092 166 265 397 530 662 828 994

35 0,096 173 276 415 553 691 864 1037

45 0,101 182 291 436 582 727 909 1091

1050 200 350 20 0,111 200 320 480 639 799 1000 1199

27 0,124 223 357 536 714 839 1116 1339

30 0,128 230 369 553 737 922 1152 1382

35 0,134 241 386 579 772 965 1206 1447

45 0,140 252 403 605 806 1008 1260 1512

1200 250 400 20 0,147 265 423 635 847 1058 1323 1588

27 0,165 297 475 713 950 1188 1485 1782

30 0,170 306 490 734 979 1224 1530 1836

35 0,178 320 513 769 1025 1282 1602 1922

45 0,186 335 536 804 1071 1339 1674 2009

1350 275 500 20 0,189 340 544 816 1089 1361 1701 2041

27 0,211 380 608 912 1215 1519 1899 2279

30 0,217 391 625 937 1250 1562 1953 2344

35 0,227 409 654 981 1308 1634 2043 2452

45 0,238 428 685 1028 1371 1714 2142 2570

1500 300 600 20 0,235 423 676 1015 1357 1692 2115 2538

27 0,263 473 757 1136 1515 1894 2367 2840

30 0,271 488 780 1171 1561 1951 2439 2927

35 0,283 509 815 1223 1630 2038 2547 3056

45 0,296 533 852 1279 1905 2131 2664 3197

1650 350 700 20 0,286 515 824 1236 1649 2059 2574 3089

27 0,321 578 924 1387 1849 2311 2889 3467

30 0,330 594 950 1426 1901 2367 2970 3564

35 0,345 621 994 1490 1987 2484 3105 3726

45 0,361 650 1040 1560 2079 2599 3249 3899

1800 350 700 20 0,343 617 988 1482 1976 2470 3087 3704

27 0,384 691 1106 1659 2212 2765 3456 4147

30 0,395 711 1138 1706 2275 2844 3555 4266

35 0,413 743 1189 1784 2379 2976 3717 4460

45 0,432 778 1244 1866 2488 3110 3888 4666

2100 350 700 20 0,472 850 1359 2039 2719 3398 4248 5098

27 0,528 950 1521 2281 3041 3802 4752 5702

30 0,543 977 1564 2346 3128 3910 4887 5864

35 0,568 1022 1636 2454 3272 4090 5112 6134

45 0,594 1069 1711 2566 3421 4277 5346 6415

2200 350 700 20 0,519 934 1495 2245 2989 3737 4671 6505

27 0,581 1046 1673 2510 3347 4183 5229 6275

30 0,598 1076 1722 2583 3444 4306 5382 6458

35 0,625 1125 1800 2700 3600 4500 5625 6750

45 0,654 1161 1858 2786 3715 4644 5805 6966

Belt Width (mm)

Grain or Other Free Flowing Material

Run of Mine Coal and Earth +

Hard Ores and Stone - Primary Crushed ++

300 2,5 1,5 1,5

400 2,5 2,0 1,8

500 3,0 2,0 1,8

600 3,0 2,5 2,3

750 3,6 3,0 2,8

900 4,0 3,3 3,0

1050 4,0 3,6 3,0

1200 4,6 3,6 3,3

1350 5,0 3,6 3,3

1500 5,0 3,6 3,3

1800 4,0 3,8



* These speeds are intended as guides to general practice and are not absolute. + Moderately abrasive materials.

++ Very abrasive materials.

Note: In the case of belts loaded on inclines of 100 or more it may be necessary to reduce the above speeds in order to achieve maximum

capacity.

TABLE 5 RECOMMENDED IDLER SPACING

TABLE 6 FRICTION FACTORS

TABLE 7 SAG FACTOR

TABLE 7(a) RECOMMENDED PERCENTAGE SAG

TABLE 8 ESTIMATED BELT MASS B

2000 and over 4,0 3,8

Belt Width (mm)

Troughing Idler - (m)Return Idlers

(m)Bulk Density of Material (t/m3)

0,5 0,8 1,2 1,6 2,0 2,5 3,0

450 1,5 1,5 1,5 1,4 1,4 1,4 1,4 3

600 1,5 1,5 1,5 1,4 1,4 1,2 1,2 3

750 1,5 1,4 1,4 1,2 1,2 1,2 1,0 3

900 1,4 1,4 1,2 1,2 1,0 1,0 1,0 3

1050 1,2 1,2 1,0 1,0 1,0 1,0 0,9 3

1200 1,2 1,2 1,0 1,0 1,0 0,9 0,9 3

1350 1,2 1,0 1,0 1,0 0,9 0,9 0,9 3

1500 1,2 1,0 1,0 1,0 0,9 0,9 0,9 3

1650 1,2 1,0 1,0 0,9 0,9 0,9 0,9 3

1800 1,2 1,0 1,0 0,9 0,9 0,9 0,8 3

2000 and over 1,0 1,0 0,9 0,9 0,9 0,8 0,8 3

Symbol Description

Value of the friction factor

Normal operating conditions.

Horizontal length up to

250 meters.

Normal operating conditions.

Horizontal length more than

250 meters.

Very well aligned structure with no tilted idlers etc.

Horizontal length more than

500 meters.

Regenerative conveyor.

fC Friction coefficient for scrapers 0,600 0,600 0,600 0,600

fS Friction coefficient for skirtboards 0,650 0,650 0,650 0,650

fX Friction coefficient for empty belt 0,022 0,020 0,020 0,018

fY Friction coefficient for loaded belt 0,027 0,022 0,020 0,018

Percentage Sag

Sag Factor

Sf

3% 4,2

2% 6,3

1,5% 8,4

Trough Angle (degree)

Fine Material

Lumps up to max lump size

Max Lump Size

20 3% 3% 3%

35 3% 2% 2%

45 3% 2% 1,5%



Note:

The values given in the table are estimated values for use in the calculation of maximum belt operating tension necessary to make the correct belt selection. When the belt specification has been determined, the mass should be checked more accurately from Table 17. If the actual mass of the specification differs considerably from the approximate value obtained from the table the tension calculation should be

rechecked using the more accurate belt mass.

TABLE 9 TYPICAL MASS OF ROTATING PARTS OF IDLERS (kg/m)

TABLE 10 MASS OF MOVING PARTS G

Belt Width (mm)

Operating Conditions

Light Duty (kg/m)

Medium Duty (kg/m)

Heavy Duty (kg/m)

500 4,1 6,2 10,3

600 5,0 7,4 12,3

750 6,2 9,3 15,5

900 7,4 11,1 18,5

1050 8,6 13,0 21,6

1200 9,8 14,8 24,7

1350 11,0 16,7 27,8

1500 12,3 18,6 30,9

1650 13,5 20,5 33,9

1800 14,7 22,3 37,0

2100 17,2 26,0 43,3

2200 18,0 27,3 45,3

Belt Width

3 Roll Carry Idlers Return Idlers 3 Roll Impact Idlers

Roll Dia Roll Dia Roll Dia

102 127 152 102 127 152 133 159

450 8,0 10,5 13,1 6,0 7,7 9,4 8,8 11,5

500 8,5 11,1 13,9 6,5 8,4 10,1 9,3 12,2

600 9,5 12,4 15,4 7,5 9,6 11,6 10,4 13,6

750 11,0 14,2 17,6 9,0 11,4 13,9 12,1 15,6

900 12,5 16,1 19,9 10,6 13,3 16,1 13,8 17,7

1050 14,0 18,0 22,2 12,1 15,2 18,4 15,4 18,8

1200 15,5 19,9 24,4 13,6 17,1 20,6 17,1 21,9

1350 17,0 21,8 26,6 15,1 19,0 22,9 18,7 24,0

1500 18,5 23,6 28,9 16,6 20,8 25,1 20,3 26,0

1650 20,0 25,5 31,2 18,1 22,7 27,4 22,0 28,9

1800 21,6 27,4 33,4 19,6 25,6 29,6 23,8 30,1

2100 24,6 31,2 37,9 22,6 28,4 34,2 27,1 34,3

2200 25,6 32,4 39,4 23,6 29,6 35,7 28,2 35,6

2400 27,6 34,9 42,4 25,7 32,1 38,7 30,4 38,4

Belt Width (mm)

Mass of Moving Parts (kg/m)

Light Duty 102mm Idlers

Light Belt

Medium Duty 127mm Idlers Moderate Belt

Heavy Duty 152mm Idlers

Heavy Belt

Extra Heavy Duty 152mm Idlers Steel Cord Belt

450 23 25 33

600 29 36 45 49

750 37 46 57 63

900 45 55 70 79

1050 52 64 82 94

1200 63 71 95 110

1350 70 82 107 127

1500 91 121 143

1650 100 132 160

1800 144 178

2100 168 205

2200 177 219



TABLE 11 DRIVE FACTOR k

Notes:

1. When calculating the driving tension required for dual drive units, the drive factor selected must correspond to the total angle of driving wrap.

2. The drive factors quoted for gravity or automatic take-up systems are minimum values based on the relationship between angle of wrap and coefficient of friction between belt and drum at the point of slip. In the case of screw take-up units, an adjustment has been made to the drive factor to allow for the extra tension which may be induced in the belt either:

a. to compensate for the effect of belt elongation when the material is loaded.

b. due to the difficulty in measuring the amount of tension applied.

3. In those cases where an electrically or hydraulically loaded winch type take-up is used, where the induced tension can be preset

and controlled, the drive factor should be selected to correspond with a gravity take-up system.

CONVEYOR BELT SELECTION

Belt carcass selection criteria

In selecting the optimum belt construction for a given application it is necessary to consider the following:

Tensile strength

The belt class required is that which has an operating tension greater than or equal to the calculated maximum unit tension T. (Table 12).

Load support Choose the lowest class which meets the tensile strength requirement. Looking at Table 14, determine which load category best describes the load being conveyed i.e. A, B, C, D or E category load. The value obtained at the intersection of the belt specification row and the load

category column gives the maximum width at which that belt specification can be used.

Number of plies for troughability The maximum number of plies allowable, in order to ensure that the empty belt will conform to the contour of the troughing idlers, must be checked referring to Table 15. For a particular belt class the value shown at the intersection of the belt width column and troughing angle

row, is the maximum number of plies that should be used.

Minimum pulley diameters If the size of the pulleys is already determined, the belt construction provisionally selected from the previous considerations can be checked against the relevant pulley diameters for suitability. For a new installation, the pulley diameters should be equal to or larger than those given in Table 13 (It should be noted that, in this context, the diameters quoted refer to the minimum pulleys around which the particular belt construction will flex satisfactorily. The conveyor designer should also take into account the gearbox ratio and required belt speed when

selecting the drive pulley diameter.)

Gauge of covers required The correct gauge of cover necessary to give protection to the belt carcass from material impact and wear must be determined by

consideration of the size and density of the material to be handled. (Table 19).

Angle of Belt Wrap at Drive

Type of

Drive

Screw Take-up

Gravity or Automatic Winch Take-up

Bare Pulley

Lagged Pulley

Bare Pulley

Lagged Pulley

150 Plain 1,5 1,0 1,08 0,670

160 Plain 1,4 0,9 0,99 0,600

170 Plain 1,3 0,9 0,91 0,550

180 Plain 1,2 0,8 0,84 0,500

190 Snubbed 1,1 0,7 0,77 0,450

200 Snubbed 1,0 0,7 0,72 0,420

210 Snubbed 1,0 0,7 0,67 0,380

220 Snubbed 0,9 0,6 0,62 0,350

230 Snubbed 0,9 0,6 0,58 0,320

240 Snubbed 0,8 0,6 0,54 0,300

340 Dual 0,5 0,4 0,29 0,143

360 Dual 0,5 0,4 0,26 0,125

380 Dual 0,5 0,3 0,23 0,108

400 Dual 0,5 0,3 0,21 0,095

420 Dual 0,4 0,3 0,19 0,084

440 Dual 0,17 0,074

460 Dual 0,15 0,064

480 Dual 0,14 0,056



Additional Information

Belt modulus

Refer to Table 20 for belt modulus.

Belt mass The mass of a particular belt construction can be determined by adding the carcass mass found in Table 17 to the combined mass of covers

found in Table 18. This will give the mass per unit area. To calculate the mass per unit length multiply by the belt width in metres.

Belt thickness

The belt thickness can be obtained from the information given in Table 16.

TABLE 12 MAXIMUM RECOMMENDED OPERATING TENSIONS

TABLE 13 RECOMMENDED MINIMUM PULLEY DIAMETERS (mm)

Textile Reinforced Multi-ply and Solid Woven Carcass Conveyor Belting

Steelcord Reinforced Conveyor Belting

Belt Class

Max recommended Operating Tension (kN/m)

Belt Class

Max recommended Operating Tension (kN/m)

160 16,0

200 20,0

250 25,0

315 31,5

400 40,0

500 50,0 St 500 75,0

630 63,0 St 630 94,0

800 80,0 St 800 120,0

1000 100,0 St 1000 150,0

1250 125,0 St 1250 187,5

1600 160,0 St 1600 240,0

2000 200,0 St 2000 300,0

St 2500 375,0

St 3150 472,0

St 4000 600,0

St 5000 750,0

St 6300 945,0

Belt Class Pulley Type

Textile Reinforced Rubber BeltingSolid Woven PVC Belting

Steelcord Reinforced

Rubber BeltingNo. of Plies

2 3 4 5

160

A 315

B 250

C 200

200

A 315

B 250

C 200

250

A 315 400

B 250 315

C 200 250

315

A 315 400 400

B 250 315 315

C 200 250 250

400

A 400 500 630 400

B 315 400 500 315

C 250 315 400 250

500

A 500 500 630 630 500 500

B 400 400 500 500 400 400

C 315 315 400 400 315 315

630

A 500 630 630 800 500 500

B 400 500 500 630 400 400

C 315 400 400 500 315 315



TABLE 14 LOAD SUPPORT

Recommended maximum belt width (mm) for correct load support. Multi-ply textile reinforced rubber belting.

800

A 630 800 800 800 500 500

B 500 630 630 630 400 400

C 400 500 500 500 315 315

1000

A 630 800 1000 1000 630 500

B 500 630 800 800 500 400

C 400 500 630 630 400 315

1250

A 1000 1000 1250 800 630

B 800 800 1000 630 500

C 630 630 800 500 400

1600

A 1000 1250 1250 1000 800

B 800 1000 1000 800 630

C 630 800 800 630 500

2000

A 1250 1400 1000 800

B 1000 1250 800 630

C 800 1000 630 500

2500

A 1000

B 800

C 630

3150

A 1250

B 1000

C 800

4000

A 1250

B 1000

C 800

5000

A 1400

B 1250

C 1000

6300

A 1400

B 1250

C 1000

Pulley types Examples

A High tension pulleys Wrap exceeding 45 Head, drive & tripper

B Low tension pulleys Wrap exceeding 45 Tail, take-up, Take-up bend

or High tension pulleys Wrap up to 45 High tension snub or bend pulleys

C Low tension pulleys Wrap up to 45 Low tension snub or bend pulleys

Belt Spec

A Light Duty

Up to 800 kg/m3

- 25mm Lumps

B Light to Medium Duty

Up to 1200 kg/m3

- 50mm Lumps

C Medium Duty

Up to 1600 kg/m3

- 100mm Lumps

D Heavy Duty

Up to 2400 kg/m3

- 250mm Lumps

E Extra Heavy Duty

Up to 3000 kg/m3

+ 250mm Lumps

160/2 750 600 500 400 Not Recommended

200/2 750 600 600 4500 Not Recommended

250/2 900 750 750 600 500

250/3 1050 900 750 600 600

315/2 900 900 750 600 500

315/3 1200 1050 1050 750 600

400/2 1200 1050 1050 900 750

400/3 1200 1050 1050 900 750

400/4 1500 1500 1350 900 750

500/2 1200 1200 1200 1050 900

500/3 1350 1200 1200 1050 900

500/4 1650 1500 1350 1200 900

500/5 1800 1800 1800 1500 1350



TABLE 15 MAXIMUM NUMBER OF PLIES RECOMMENDED FOR CORRECT EMPTY BELT TROUGHING

TABLE 16 CARCASS THICKNESS (mm)

630/2 1200 1200 1200 1050 900

630/3 1650 1350 1200 1050 1050

630/4 1650 1500 1350 1200 1050

630/5 2100 2100 1800 1650 1350

800/2 1650 1500 1500 1350 1200

800/3 1800 1650 1500 1350 1200

800/4 2100 1800 1650 1500 1350

800/5 2400 2400 2100 1800 1500

1000/2 1800 1650 1500 1350 1200

1000/3 2100 1650 1500 1350 1200

1000/4 2400 1800 1800 1500 1350

1000/5 2400 2400 2200 1800 1500

1250/3 2100 1800 1800 1350 1200

1250/4 2400 2200 2200 1650 1500

1250/5 2400 2400 2400 1800 1800

1600/3 2400 2400 1800 1650 1650

1600/4 2400 2400 2200 1800 1800

1600/5 2400 2400 2400 2200 1800

2000/4 2400 2400 2400 1800 1800

2000/5 2400 2400 2400 2200 2100

Belt Class

Belt Width (mm) Troughing Angle350 400 450 500 600 750 900 1050 1200 1350 1500 1650 1800 2100 2200

1602 2 2 2 2 2 2 2 2 2 2 2 2 2 2 20

2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 35

2002 2 2 2 2 2 2 2 2 2 2 2 2 2 2 20

2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 35

250- 3 3 3 3 3 3 3 3 3 3 3 3 3 3 20

- 2 2 2 3 3 3 3 3 3 3 3 3 3 3 35

315- 2 3 3 3 4 4 4 4 4 4 4 4 4 4 20

- 2 3 3 3 3 4 4 4 4 4 4 4 4 4 35

400- 2 4 4 4 4 4 4 4 4 4 4 4 4 4 20

- - 3 3 3 4 4 4 4 4 4 4 4 4 4 35

500- - 4 4 4 4 4 4 4 4 4 4 4 4 4 20

- - 3 3 3 4 4 4 4 4 4 4 4 4 4 35

630- - 4 4 4 4 4 4 4 4 4 4 4 4 4 20

- - 2 2 3 4 4 4 4 4 4 4 4 4 4 35

800- - 3 3 4 4 4 4 4 4 4 4 4 4 4 20

- - 2 2 3 4 4 4 4 4 4 4 4 4 4 35

1000- - - - 4 4 4 4 4 4 4 4 4 4 4 20

- - - - 2 3 4 4 4 4 4 4 4 4 4 35

1250- - - - 4 4 4 4 4 4 4 4 4 4 4 20

- - - - 3 3 4 4 4 4 4 4 4 4 4 35

1600- - - - 3 4 4 4 4 4 4 4 4 4 4 20

- - - - - 3 4 4 4 4 4 4 4 4 4 35

2000- - - - - 4 5 5 5 5 5 5 5 5 5 20

- - - - - - 4 4 5 5 5 5 5 5 5 35

Belt Class

Textile Reinforced Rubber Belting No. of Plies Solid Woven

PVC BeltingSteelcord Reinforced

Rubber Belting2 3 4 5

160 2,0

200 2,6

250 2,7 3,2

315 2,8 3,5 4,9



Add the thickness of the covers to get the total belt thickness

TABLE 17 MASS OF BELT CARCASS (kg/m2)

To obtain total belt mass add the mass of the combined covers from Table 18.

The mass per unit length is determined by multiplying the total mass by the belt width in metres.

TABLE 18 MASS OF COVERS PER mm OF THICKNESS (kg/m2)

RATE OF WEAR VS THICKNESS OF COVER

400 3,0 3,8 5,0

500 4,0 4,2 5,2 5,9 5,9 3,2

630 4,3 5,2 5,8 6,6 6,2 3,2

800 5,0 6,0 6,9 7,2 6,9 3,7

1000 5,7 6,5 7,6 8,5 7,4 3,7

1250 8,4 9,6 10,0 8,4 3,7

1600 9,5 10,5 11,0 9,9 5,4

2000 12,0 13,0 12,4 5,4

2500 7,0

3150 8,0

4000 9,0

5000 11,0

6300 12,0

Belt Class

Textile Reinforced Rubber Belting No. of Plies

Solid Woven PVC Belting

With Nominal PVC Coating

Steelcord Reinforced Rubber Belting

2 3 4 5

160 2,8

200 3,0

250 3,1 3,9

315 3,4 4,2 9,0

400 3,7 4,4 6,0 9,4

500 4,3 4,8 6,4 7,5 9,7 7,5

630 4,8 5,2 6,8 8,0 10,5 7,7

800 5,6 6,4 7,2 8,5 11,0 8,2

1000 6,5 7,3 8,5 9,0 11,7 9,0

1250 8,9 9,7 10,5 13,0 9,7

1600 10,7 11,5 12,5 15,0 13,4

2000 14,2 14,9 18,0 15,3

2500 18,7

3150 22,4

4000 28,4

5000 35,1

6300 38,7

Grade of CoverMass

(kg/m2)

N 1,14

M 1,10

OR 1,41

GF 1,37

FR 1,27

Grade of CoverMass

(kg/m2)

PHR 1,17

SPHR 1,21

DHR 1,34

PVC 1,37

Nitrile 1,32



The rate at which a belt cover wears is related to the thickness of the cover and to the impact energy imparted by material lumps.

Impact energy can be calculated for any material of known lump mass and vertical velocity.

- x v J

- Impact Energy (J) - Mass of lump (kg) v - Verticle velocity (m/s)

TABLE 19 MINIMUM BELT TOP COVER GAUGE GUIDE

Cycle time - 2L/S

TABLE 20 BELT MODULUS (kN/m)

Cycle time

s

Material Class A

Non abrasive material such as lime, charcoal, wood chips, bituminous

coal grain

Material Class B

Abrasive material such as salt, anthracite coal, phosphate rock,

limestone, fullers earth

Material Class C

Very abrasive material such as slag, copper ore,

sinter, coke sand, flue dust

Material Class D

Very sharp abrasive material such as quartz, some ores,

foundry refuse, glass batch, iron borings

Lump size (mm) Lump size (mm) Lump size (mm) Lump size (mm)

dust to 12

12 to 50

50 to

150

150 and over

dust to 12

12 to 50

50 to

150

150 and over

dust to 12

12 to 50

50 to

150

150 and over

dust to 12

12 to 50

50 to

150

150 and over

12 2,0 3,0 6,0 8,0 3,0 6,0 10,0 10,0 6,0 10,0 10,0 10,0 8,0 10,0 10,0 10,0

25 2,0 2,5 3,0 5,0 2,5 3,0 6,0 10,0 3,0 6,0 10,0 10,0 4,0 8,0 10,0 10,0

40 1,0 2,5 3,0 5,0 2,5 3,0 4,0 5,0 3,0 3,0 6,0 10,0 3,0 4,0 8,0 10,0

60 1,0 2,5 3,0 5,0 2,5 3,0 4,0 5,0 3,0 3,0 5,0 6,0 3,0 3,0 6,0 10,0

90 1,0 2,5 3,0 5,0 2,5 3,0 4,0 5,0 3,0 3,0 5,0 5,0 3,0 3,0 6,0 6,0

120 1,0 2,5 3,0 5,0 2,5 3,0 4,0 5,0 3,0 3,0 4,0 5,0 3,0 3,0 5,0 6,0

180 1,0 2,5 3,0 5,0 2,5 3,0 4,0 5,0 3,0 3,0 4,0 5,0 3,0 3,0 5,0 6,0

240+ 1,0 2,5 3,0 5,0 2,0 3,0 4,0 5,0 3,0 3,0 4,0 5,0 3,0 3,0 5,0 6,0

Belt Class

Multi-ply Textile

Reinforced Belting

Solid Woven PVC Belting

Steelcord Reinforced

Rubber Belting

160 1060

200 1330

250 1660

315 2070 1750

400 2950 2220

500 3330 2800 29000

630 4200 3500 37700

800 5330 4440 47900

1000 6660 5550 59800

1250 8330 6900 74800

1600 10660 8890 95800

2000 13330 11110 119700

2500 149700

3150 188600

4000 240000



TABULATOR CALCULATIONS

For the purposes of

1. Calculating vertical curves, or 2. Determining belt tension for conveyors of undulating profile.

It is necessary to calculate the belt tensions at various points on the conveyor. Calculating the tension at any point along the conveyor.

The tabulation method described below is a convenient means of calculating the tensions at any point on the conveyor.

Blank copies of the "Conveyor Tabulation Sheets" are available from Dunlop Africa Industrial Products.

The following method is used to determine the tension at any point along the conveyor:

1. Calculate the length correction factor. 2. Look up the mass of moving parts in Table 10. 3. Calculate the mass of the load from the design capacity and the belt speed. 4. Calculate the maximum effective tension under constant speed operation. This will always occur when all the non-declined

sections of the conveyor are fully loaded and the declined sections empty. 5. Determine the minimum value for the slack side tension under maximum load condition. 6. Commencing from immediately behind the drive, label each pulley, intersection point and loading section. Start and end point of

each of the load lengths should also be labelled. 7. Determine the effective tension required to overcome the frictional and gravitational resistances for each of the segments of the

conveyor by using formulae on page 4. The value of 12, determined in 5 above, is used to calculate the

effective tension to overcome pulley friction. 8. The effective tension at any point on the conveyor is the sum of the effective tensions of all preceeding segments. The total

effective tension for the conveyor is the sum of the effective tensions for all segments. 9. The tension at any point 'x' on the conveyor is made up of the effective tension at point 'x' plus the slope tension at point 'x'.

Superimposed on this is the tension applied by the take-up system. The tension applied by the take-up is given by the worst case T2 value i.e. the value of T2 which

a. prevents slip at the highest Te value and, b. limits sag between carry idlers.

It may be found that the value of T2 obtained when the maximum effective tension has been calculated is different to that used in the

calculations. If this is the case the new T2 value is used to calculate tensions at each point.

Steps 7, 8 and 9 should be repeated for four load cases viz empty, fully loaded, non-declined sections loaded and declined sections loaded.

EXAMPLE

Step 1

5000 300000

6300 377200

Belt width 1200 mm

Conveyor length 500 m

Lift 45 m

Max capacity 4500 t/hr

Belt speed 3,5 m/s

Skirt length 3 m

Material conveyed Iron Ore

Lump size 100 mm

Bulk density 2,4 t/m3

Carry idler diameter 127 mm

Carry idler spacing 1,2 m

Return idler diameter 127 mm

Return idler spacing 3,6 m

Impact idler diameter 159 mm

Impact idler spacing 0,45 m

Drive wrap 210 degree

Drive surface Rubber lagged

Take-up type Gravity



Calculate the length correction factor

Step 2

From Table 10 the mass of the moving parts for a 1200 mm wide conveyor of medium duty is 71 kg/m.

Step 3

Calculate the mass of the load

Step 4

Calculate the maximum effective tension when the non-declined sections of the conveyor are all carrying load and the declined sections

have no load. The total horizontal length of non-declined sections is 20 + 330 = 350 m.

The overall change in elevation on the non-declined sections is 70 in. Note that the actual length of the conveyor is used to calculate Tx and

only the loaded length to calculate Ty. The length correction factor is a constant and is used to convert the actual length to a corrected

length. The friction factors are determined by the total conveyor length in all cases.

Effective tension to move the empty belt.

Effective tension to move the load horizontally.

Effective tension to lift the load.

Effective tension to overcome skirtboard friction The inter-skirtboard width is assumed to be 2/3 of the belt width i.e. 0,8 m.

The total effective tension is the sum of the above four.

C = L + 70

L

= 570

500

= 1,14

Q = 0,278

s

= 0,278 x 4500

3,5

= 357,4 kg/m

Tx = 9,8G x fx C x L

= 9,8 x 71 x 0,020 x 1,14 x 500

= 7932N

Ty = 9,8Q x fy C x L

= 9,8 x 357,4 x 0,020 x 1,14 x 350

= 30745N

Tz = 9,8Q x H

= 9,8 x 357,4 x 70

= 245176N

Tus = 9,8fs x Q x Ls

S x b2

= 9,8 x 357,4 x 0,020 x 1,14 x 350

3,5 x 0,64

= 3050N

Te = Tx + Ty + Tz + Tus

= 7932 + 30745 + 245176 + 3050

= 286903N



Step 5

The minimum slack side tension to prevent slip is:

The minimum slack side tension to prevent excessive belt sag is:

From Table 8 the estimated belt mass is 14,8 kg/m

Since

Tm > Ts

T2 = Tm

i.e. T2 = 109023N

Step 6

The conveyor is labelled from A to 0 as shown on example sheets 1 to 4.

Step 7

Calculations of the effective tension for each segment (or run) is shown on Sheet 1 for the empty belt, Sheet 2 for the fully loaded belt,

Sheet 3 for the case where only non-decline sections are loaded and Sheet 4 where only the decline sections are loaded.

Step 8

The accumulated effective tension column is the sum of the effective tensions of the current segment and all preceeding segments.

Step 9

The total effective tension for each load case is the value in the last row of the column titled 'Accumulated Effective Tension'.

The reason for the difference between the effective tension determine step 4 and that on Sheet 3 is the more accurate figures used for mass

of the moving parts on the tabulation sheets.

The tension at any point along the conveyor can now be determined, all load cases, by adding the effective tension at the point to the slope

tension at the point and then adding the worst case T2 value.

The highest Te value occurs when all non-declines are loaded. i.e. Te = 283609N

Based on this value

Tm = k x Te

k = 0,38 from Table 11 and hence

Tm = 0,38 x 286903

= 109023

Ts = 9,8Sf x (B + Q) x Id

= 9,8 x 6,3 x (14,8 + 357,4) x 1,2

= 27576N

For the empty belt Te = 7665N

For the fully loaded belt Te = 174188N

For all non-declines loaded Te = 283609N

For only declines loaded Te = -101755N

Tm = k x Te

= 0,38 x 283609N

= 107771N



Since Ts, calculated in step 5, is less than Tm

T2 = Tm

i.e. T2 = 107771N

Thus, for example, the effective tension at run L - M takes the following values:

From these it is determined that the tension at point M under the four cases, given by

Te + T2 + Th is

Empty belt

4302 + 107771 + 0

= 112073N

Fully loaded belt

-24577 + 107771 + 0

= 83194N

Non-declines loaded

6059 + 107771 + 0

= 113830N

Declines loaded

-26334 + 107771 + 0

= 81437N

1. Empty Belt 4302N

2. Fully loaded - 24577N

3. Non-declines loaded 6059N

4. Declines loaded -26334N

CLIENT NAME CONVEYOR EQUIPMENT NO.

Belt width W 1200 mm

Conveyor length L 500 m

Lift H 45 m


Belt speed S 3,5 m/s

Skirt length Ls 3 m


Lump size 100 mm

Bulk densiy 2,4 t/m3

Corrected length Lc 570 m

Correction factor C 1,14

Idler Data Carry Return Impact

Trough Angle 35 0 35 degree

Roll Diameter 127 127 159 mm

Spacing 1,2 3,6 0,45 m

Rotating Parts Mass M 19,9 17,1 22,9 kg/set

Friction Factors Rotating Parts fx 0,020

Load Friction fy 0,022

Skirt Friction fs 0,65

Scraper Friction fc 0,60

Pulleys Diameter Location

Head 630 mm O

Drive Head mm O

HT Bend - mm -

Tail 500 mm I

Take-up 500 mm E

Take-up Bend 500 mm D,F

LT Bend 450 mm B

Tripper - mm -

Drive & Take-up Angle of Wrap 210

Drive Surface Lagged Bare

Take-up Type Gravity ScrewDrive Factor k 0,38



SHEET 1 - EMPTY BELT

Run

Length of Run

(m)

Lr

Idler Mass

(kg/m)

Mr = M/Id

Belt Mass

(kg/m) B

Load Mass

(kg/m)

Qr

Tension to Overcome Friction (N) Lift of

Run (m)

Hr

Tension to Overcome

Gravity (N)

9,8QHr

Effective Tension for Run

(N)

Ter

Accumulative Effective Tension

(N)

Te

Absorbed Power

(W)

TeS

Idlers

9,8LrCfxMr

Belt

9,8LrCfxB

Pulley

0,01(do/D)

T2

Load

9,8LrCfxQ

A-B 2 0 14,8 0 0 7 178 0 0 0 185 185 647

B-C 98 5,7 14,8 0 125 324 0 0 25 0 449 634 2218

C-D 15 5,7 14,8 0 19 50 178 0 -3 0 247 881 3082

D-E 0 0 14,8 0 0 0 178 0 0 0 178 1059 3706

E-F 0 0 14,8 0 0 0 178 0 0 0 178 1237 4330

F-G 330 5,7 14,8 0 420 1091 0 0 -67 0 1512 2749 9621

G-H 50 5,7 14,8 0 64 165 0 0 10 0 229 2978 10422

H-I 20 5,7 14,8 0 25 66 178 0 0 0 270 3248 11367

I-J 2 0 14,8 0 0 7 0 0 0 0 7 3255 11390

J-K 3 50,9 14,8 0 34 10 178 0 0 0 222 3477 12168

K-L 17 16,5 14,8 0 63 56 178 0 0 0 297 3774 13208

L-M 50 16,5 14,8 0 184 165 178 0 -10 0 528 4302 15055

M-N 330 16,5 14,8 0 1217 1091 178 0 70 0 2486 6788 23757

N-O 100 16,5 14,8 0 369 331 178 0 -25 0 887 7665 36829




Lift H 45 m



Skirt length Ls 3 m


Lump size 100 mm







Spacing 1,2 3,6 0,45 m







Head 630 mm O

Drive Head mm O

HT Bend - mm -

Tail 500 mm I

Take-up 500 mm E


LT Bend 450 mm B

Tripper - mm -




Run

Length of Run

(m)

Lr

Idler Mass

(kg/m)

Mr = M/Id

Belt Mass

(kg/m) B

Load Mass

(kg/m)

Qr


Run (m)

Hr

Tension to Overcome

Gravity (N)

9,8QHr


(N)

Ter


(N)

Te

Absorbed Power

(W)

TeS

Idlers

9,8LrCfxMr

Belt

9,8LrCfxB

Pulley

0,01(do/D)

T2

Load

9,8LrCfxQ

A-B 2 0 14,8 0 0 7 178 0 0 0 185 185 647

B-C 98 5,7 14,8 0 125 324 0 0 25 0 449 634 2218

C-D 15 5,7 14,8 0 19 50 178 0 -3 0 247 881 3082

D-E 0 0 14,8 0 0 0 178 0 0 0 178 1059 3706

E-F 0 0 14,8 0 0 0 178 0 0 0 178 1237 4330

F-G 330 5,7 14,8 0 420 1091 0 0 -67 0 1512 2749 9621

G-H 50 5,7 14,8 0 64 165 0 0 10 0 229 2978 10422

H-I 20 5,7 14,8 0 25 66 178 0 0 0 270 3248 11367



SHEET 2 - FULLY LOADED BELT

SHEET 3 - NON-DECLINES LOADED

I-J 2 0 14,8 0 0 7 0 0 0 0 7 3255 11390

J-K 3 50,9 14,8 357,4 34 10 178 264 0 0 485 3740 13090

K-L 17 16,5 14,8 357,4 63 56 178 1493 0 0 1791 5531 19357

L-M 50 16,5 14,8 357,4 184 165 178 4393 -10 -35028 -30108 -24577 -86019

M-N 330 16,5 14,8 357,4 1217 1091 178 28991 70 245196 276673 252096 882335

N-O 100 16,5 14,8 357,4 369 331 178 8785 -25 -8750 -77908 174188 609659




Lift H 45 m



Skirt length Ls 3 m


Lump size 100 mm







Spacing 1,2 3,6 0,45 m







Head 630 mm O

Drive Head mm O

HT Bend - mm -

Tail 500 mm I

Take-up 500 mm E


LT Bend 450 mm B

Tripper - mm -




Run

Length of Run

(m)

Lr

Idler Mass

(kg/m)

Mr = M/Id

Belt Mass

(kg/m) B

Load Mass

(kg/m)

Qr


Run (m)

Hr

Tension to Overcome

Gravity (N)

9,8QHr


(N)

Ter


(N)

Te

Absorbed Power

(W)

TeS

Idlers

9,8LrCfxMr

Belt

9,8LrCfxB

Pulley

0,01(do/D)

T2

Load

9,8LrCfxQ

A-B 2 0 14,8 0 0 7 178 0 0 0 185 185 647

B-C 98 5,7 14,8 0 125 324 0 0 25 0 449 634 2218

C-D 15 5,7 14,8 0 19 50 178 0 -3 0 247 881 3082

D-E 0 0 14,8 0 0 0 178 0 0 0 178 1059 3706

E-F 0 0 14,8 0 0 0 178 0 0 0 178 1237 4330

F-G 330 5,7 14,8 0 420 1091 0 0 -67 0 1512 2749 9621

G-H 50 5,7 14,8 0 64 165 0 0 10 0 229 2978 10422

H-I 20 5,7 14,8 0 25 66 178 0 0 0 270 3248 11367

I-J 2 0 14,8 0 0 7 0 0 0 0 7 3255 11390

J-K 3 50,9 14,8 357,4 34 10 178 264 0 0 485 3740 13090

K-L 17 16,5 14,8 357,4 63 56 178 1493 0 0 1791 5531 19357

L-M 50 16,5 14,8 0 184 165 178 0 -10 0 528 6059 21205

M-N 330 16,5 14,8 357,4 1217 1091 178 28991 70 245196 276673 282732 989559

N-O 100 16,5 14,8 0 369 331 178 0 -25 0 877 283609 992631




SHEET 4 - DECLINES LOADED



Lift H 45 m



Skirt length Ls 3 m


Lump size 100 mm







Spacing 1,2 3,6 0,45 m







Head 630 mm O

Drive Head mm O

HT Bend - mm -

Tail 500 mm I

Take-up 500 mm E


LT Bend 450 mm B

Tripper - mm -




Run

Length of Run

(m)

Lr

Idler Mass

(kg/m)

Mr = M/Id

Belt Mass

(kg/m) B

Load Mass

(kg/m)

Qr


Run (m)

Hr

Tension to Overcome

Gravity (N)

9,8QHr


(N)

Ter


(N)

Te

Absorbed Power

(W)

TeS

Idlers

9,8LrCfxMr

Belt

9,8LrCfxB

Pulley

0,01(do/D)

T2

Load

9,8LrCfxQ

A-B 2 0 14,8 0 0 7 178 0 0 0 185 185 647

B-C 98 5,7 14,8 0 125 324 0 0 25 0 449 634 2218

C-D 15 5,7 14,8 0 19 50 178 0 -3 0 247 881 3082

D-E 0 0 14,8 0 0 0 178 0 0 0 178 1059 3706

E-F 0 0 14,8 0 0 0 178 0 0 0 178 1237 4330

F-G 330 5,7 14,8 0 420 1091 0 0 -67 0 1512 2749 9621

G-H 50 5,7 14,8 0 64 165 0 0 10 0 229 2978 10422

H-I 20 5,7 14,8 0 25 66 178 0 0 0 270 3248 11367

I-J 2 0 14,8 0 0 7 0 0 0 0 7 3255 11390

J-K 3 50,9 14,8 0 34 10 178 0 0 0 222 3477 12168

K-L 17 16,5 14,8 0 63 56 178 0 0 0 297 3774 13208

L-M 50 16,5 14,8 357,4 184 165 178 4393 -10 -35028 -30108 -26334 -92169

M-N 330 16,5 14,8 0 1217 1091 178 0 70 0 2486 -23848 -83467

N-O 100 16,5 14,8 357,4 369 331 178 8785 -25 -87570 -77907 -101755 -356143


Belt width W _______ mm

Conveyor length L _______ m

Lift H _______ m

Max capacity _______ t/hr

Belt speed S _______ m/s

Skirt length Ls _______ m

Material conveyed _______

Lump size _______ mm

Bulk densiy _______ t/m3

Corrected length Lc _______ m

Correction factor C _______


Trough Angle _____ _____ _____ degree

Roll Diameter _____ _____ _____ mm

Spacing _____ _____ _____ m

Rotating Parts Mass M _____ _____ _____ kg/set



TENSION TABULATOR

VERTICAL CURVES

Design of vertical curves

It is necessary to calculate the tension at the point under consideration following the method described in Tabulator Calculations.

Concave curves

The worst condition exists when the belt is loaded to the start of the curve and under these conditions the minimum radius of curvature to

prevent the belt lifting off the idlers is

Where

R = radius of curvature (m)

Tp = Belt tension at the point under consideration (kN)

B = Belt mass per unit length (kg/m)

Convex curve requirements

The following conditions must be satisfied

1. Minimum radius to prevent overstress of the belt edges

Friction Factors Rotating Parts fx _______

Load Friction fy _______

Skirt Friction fs _______

Scraper Friction fc _______


Head _______ mm _______

Drive _______ mm _______

HT Bend _______ mm _______

Tail _______ mm _______

Take-up _______ mm _______

Take-up Bend _______ mm _______

LT Bend _______ mm _______

Tripper _______ mm _______

Drive & Take-up Angle of Wrap _______


Take-up Type Gravity ScrewDrive Factor k _______

Run

Length of Run

(m)

Lr

Idler Mass

(kg/m)

Mr = M/Id

Belt Mass

(kg/m) B

Load Mass

(kg/m)

Qr


Run (m)

Hr

Tension to Overcome

Gravity (N)

9,8QHr


(N)

Ter


(N)

Te

Absorbed Power

(W)

TeS

Idlers

9,8LrCfxMr

Belt

9,8LrCfxB

Pulley

0,01(do/D)

T2

Load

9,8LrCfxQ

R = 113 Tp

B



2. Minimum radius to prevent buckling

3. Maximum allowable change of incline per idler to prevent overstress of belt edges

4. Maximum allowable change of incline per idler to prevent buckling

The curve must be designed with a radius at least large enough to satisfy conditions 1 and 2 and the idler spacing must ensure that

conditions 3 and 4 are satisfied.

tr = Rated belt tension (kN/m)

R = Radius of curvature (m) = Troughing angle (degrees) W = Belt width (mm) E = Belt modulus (kN/m)

tc = Belt tension at the curve (kN/m)

MAXIMUM INCLINE ANGLE

1. Conventional smooth surface conveyor belts 2. Ruftop package handling belts 3. Chevron top belts 4. Boxes belts with flexible side walls 5. Sandwich type conveyors 6. Elevator belts

GRAPH FOR ESTIMATING BELT LENGTH/ROLLED BELT DIAMETER

Belt length/rolled belt diameter

D = rolled belt diameter (mm) L = belt length (m) t = belt thickness (mm) d = core diameter (mm)

N = number of coils on roll

Belt length:

R = Sin x W x E

4494 (tr - tc)

R = Sin x W x E

8988 (tr - 5,2)

= 5,1 (tr - tc) x 1000

W x E x Sin

= 2,55 (tc - 5) x 1000

W x E x Sin

(D + d)N



Rolled belt diameter:

USEFUL DATA CONVERSION FACTORS

Imperial to metric

L = 2

Assuming the length of belt is large and the thickness not abnormally small, then the core diameter can be neglected in approximate calculations.

or

Where d 0,3m for general stock belting and up to 0,5m for heavy rolls of belting, such as steelcord belting or very wide belts.

To convert from To Multiply by

in mm 25,4

in cm 2,54

ft m 0,3048

in2 cm2



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dunlop conveyor belt design manual

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