Listing of international, European and national standards relating to belt conveyors. Part 1.

The following is a listing of the principal international and national standards relating to belt conveyors. It is not claimed to be exhaustive.

International Organisation for Standardisation (ISO)

• ISO 10247:1990 Conveyor belts Characteristics of covers Classification.
• ISO 1120:2002 Conveyor belts Determination of strength of mechanical fastenings ± Static test method.
• ISO 14890:2003 Conveyor belts Specification for rubber or plastics covered conveyor belts of textile construction for general use.
• ISO 15236-1:2005 Steel cord conveyor belts Part 1: Design, dimensions and mechanical requirements for conveyor belts for general use.
• ISO 15236-2:2004 Steel cord conveyor belts Part 2: Preferred belt types.
• ISO 15236-4:2004 Steel cord conveyor belts Part 4: Vulcanised belt joints
• ISO 1535:1975 Continuous mechanical handling equipment for loose bulk materials Troughed belt conveyors (other than portable conveyors) Belts.
• ISO 1536:1975 Continuous mechanical handling equipment for loose bulk materials Troughed belt conveyors (other than portable conveyors) Belt pulleys.
• ISO 1537:1975 Continuous mechanical handling equipment for loose bulk materials Troughed belt conveyors (other than portable conveyors) Idlers.
• ISO16851:2004 Textile conveyor belts Determination of the net length of an endless (spliced) conveyor belt.
• ISO 1816:1975 Continuous mechanical handling equipment for loose bulk materials and unit loads Belt conveyors Basic characteristics of motorised driving pulleys.
• ISO 18573:2003 Conveyor belts Test atmospheres and conditioning periods.
• ISO 2109:1975 Continuous mechanical handling equipment Light duty belt conveyors for loose bulk materials.
• ISO 251:2003 Conveyor belts with textile carcass Widths and lengths
  ISO 252:1999 Textile conveyor belts Adhesive strength between constitutive
  elements Part 1: Methods of test.
• ISO 282:1999 Conveyor belts Sampling.
• ISO 283-1:2000 Textile conveyor belts Full thickness tensile testing Part 1: Determination of tensile strength, elongation at break and elongation at the reference load.
• ISO 284:2003 Conveyor belts Electrical conductivity Specification and test method.
• ISO 340:2004 Conveyor belts Laboratory scale flammability characteristics Requirements and test method.
• ISO 3684:1990 Conveyor belts Determination of minimum pulley diameters.
• ISO 3870:1976 Conveyor belts (fabric carcass), with length between pulley centres up to 300 m, for loose bulk materials Adjustment of take-up device.
• ISO 4123:1979 Belt conveyors Impact rings for carrying idlers and discs forreturn idlers Main dimensions.
• ISO 433:1991 Conveyor belts Marking.
• ISO 5048:1989 Continuous mechanical handling equipment Belt conveyors with carrying idlers Calculation of operating power and tensile forces.
• ISO 505:1999 Conveyor belts Method for the determination of the tear propagation resistance of textile conveyor belts.
• ISO 5284:1986 Conveyor belts List of equivalent terms.
• ISO 5285:2004 Conveyor belts Guidelines for storage and handling.
• ISO 5293:2004 Conveyor belts Determination of minimum transition distance on three idler rollers
  ISO 583-1:1999 Conveyor belts with a textile carcass Total thickness and thickness of elements Part 1: Methods of test.
• ISO 583:1990 Conveyor belts with a textile carcass Tolerances on total thickness and thickness of covers Direct measurement method.
• ISO 703-1:1999 Conveyor belts Transverse flexibility and troughability Part 1: Test method.
• ISO 703:1988 Conveyor belts Troughability Characteristics of transverse flexibility and test method.
• ISO 7149:1982 Continuous handling equipment Safety code Special rules.
• ISO 7590:2001 Steel cord conveyor belts Methods for the determination of total thickness and cover thickness.
• ISO 7622-1:1984 Steel cord conveyor belts Longitudinal traction test Part 1: Measurement of elongation.
• ISO 7622-2:1984 Steel cord conveyor belts Longitudinal traction test Part 2: Measurement of tensile strength.
• ISO 7623:1996 Steel cord conveyor belts Cord-to-coating bond test Initial test and after thermal treatment.
• ISO 8094:1984 Steel cord conveyor belts Adhesion strength test of the cover to the core layer.
• ISO 9856:2003 Conveyor belts Determination of elastic and permanent elongation and calculation of elastic modulus.
• ISO/FDIS 252 Conveyor belts Adhesion between constitutive elements Test methods.
• ISO/FDIS 283 Textile conveyor belts Full thickness tensile strength, elongation at break and elongation at the reference load Test method.
• ISO/FDIS 583 Conveyor belts with a textile carcass Total belt thickness andthickness of constitutive elements Test methods.
• ISO/FDIS 703 Conveyor belts Transverse flexibility (troughability) Test method.
• ISO/TR 5045:1979 Continuous mechanical handling equipment Safety code for belt conveyors Examples for guarding of nip points.
• ISO/TR 8435:1984 Continuous mechanical handling equipment Safety code for belt conveyors examples for protection of pinch points on idlers.

ABRASION RESISTANCE OF CONVEYOR BELTS

There are many system design recommendations to improve belt cover life both from an abrasion and a cut & gouge standpoint, regardless of compound. From an abrasion standpoint,
the following guidelines should be used:

• The faster the speed of the conveyor, the greater the wear. The material bounces and
  abrades in the loading zone until it gets up to the same speed of the belt. The higher the
  relative speed differential, the more wear will occur.
• The shorter the center to center length of the system, the greater the wear. This is simply due to more cycles per hour.
• The higher the angle of incline at the loading point of the conveyor, the greater the wear. The higher angle makes it tougher for the material to get up to the speed of the belt (i.e. 15ÿ incline conveyor will wear faster than a flat conveyor)
• The higher the angle of chute, the greater the wear. The more the material is being
  transferred to a conveyor belt in the horizontal direction instead of vertical, the less the wear. Therefore, a chute with a 30° angle will project the material at a greater horizontal velocity than a chute with a 90° straight down drop, reducing the wear.
• The higher the drop height, the greater the wear.
• The higher the feed angle from one conveyor to the next, the greater the wear. This means
  that a conveyor belt that is fed inline from another conveyor will wear less than one that is
  being fed at an angle.
• Scraper tension is critical. Too loose and the material will not be removed from the cover.
  Too tight and the cover will get worn away significantly faster.

If the material being conveyed is large enough and/or sharp enough, cut and gouge damage to
the cover will occur. From this standpoint, the following guidelines should be used:

• The higher the drop height, the greater the damage to the belt cover and carcass. Installing
  bars in the crusher or chute to slow down the material when practical will reduce the material speed and impact energy.
• Loading fines on to the belt before the large diameter material will reduce impact damage
  dramatically. The fines absorb the high impact energy, protecting the belt cover.
• Impact idlers reduce the amount of impact damage to a belt in comparison to impact beds
  because the belt has more room to deflect.
  

Belt Engineering and Reference Data

Conveyor Belt Tension Calculation

The purpose of this section is to provide a simple and efficient method to select the best conveyor belt for many common applications. It may provide a way to quickly double check a given design. If there are doubts or discrepancies, get a recommendation from a reliable conveyor belt manufacturer. The best selection will usually result in the lowest total cost-per-ton over the service life of the conveyor belt.

The best selection depends on acquiring complete operating and environmental information. It is best to get this information immediately and before any calculations are attempted. This information should include:

1. Carrying Surface. State if load surface of belt is supported by flat or troughed idlers or type of flat slider bed surface. State angle of troughed idlers.
2. Drive Data.
   1. Motor nameplate horsepower
   2. Identify if single or multiple drive pulleys
   3. Are drive pulleys bare or lagged?
   4. Total belt wrap (degrees) on drive pulley(s)
   5. Location of drive
3. Environment. Temperature, chemicals, oils, and any special conditions.
4. Height. Vertical difference of head and tail (terminal) pulleys, elevation (ft.).
5. Length. Distance (ft.) between head and tail pulley.
6. Loading Rate. Tons/hour.
7. Material. Type, temperature, weight per cu. ft., size and percentage of maximum lumps.
8. Pulley Diameter. In addition to tail and head pulley, and carry idlers, any pulley that changes belt direction (identify each--include in system sketch).
9. Speed. (Ft./minute) of belt.
10. Take-up. Type (mechanical screw or automatic), location, and total amount of movement (included in sketch).
11. Width of Belt. (Inches) Include width of pulley face width, if known.

First, the Effective Belt Tension (TE) must be calculated. TE is the sum of the tension required to move the empty belt (TC), the tension required to move the load horizontally (TL), and the tension required to lift the load (TH).

Example 1. TE = TC + TL + TH

Calculations

TC = F1 x L x CW
F1 = .035" [Normal friction factor for average conditions (over 20°F) to move empty belt.]

L = Belt length (ft.)CW = Weight of conveyor belt components. See Table A.

TL = F2 x L x MW
F2 = .04" [Normal friction factor to move load horizontally.]

L = Belt length (ft.)MW = Material weight (lbs. per lineal foot).

MW = 33.3 TPH/Belt Speed (fpm) o rTotal material load in lbs/L.

TH = H x MW
H = Difference in elevation of terminal pulleys (ft.)

TE = TC + TL + TH
(Continue with calculation of TS and then TO.)

Table A
Weight of Moving Conveyor Components

Belt Width CW Factor with Regular 5"Idlers (See Notes) 12" 12 18" 18 24" 24 30" 30 36" 36 42" 42 48" 48 54" 54 60" 60 NOTE: For 4" idlers, multiply by .85 For 6" idlers, multiply by 1.33 For lengths (L) less than 150 gt., multiply by 100´ to 150´ -- 1.1 75´ to 99´ -- 1.2 50´ to 74´ -- 1.3 30´ to 49´ -- 1.5 15´ to 29´ -- 3.0

Table B
Drive Factor (D)

Screw Take-Up Gravity or Flexible Take-Up Angle of Belt Wrap at Drive Type of Drive Bare Pulley Lagged Pulley Bare Pulley Lagged Pulley 150 Plain 1.5 1.0 1.08 .67 160 Plain 1.4 .9 .99 .60 170 Plain 1.3 .9 .91 .55 180 Plain 1.2 .8 .84 .50 190 Snubbed 1.1 .7 .77 .45 200 Snubbed 1.0 .7 .72 ..42 210 Snubbed 1.0 .7 .67 .38 220 Snubbed .9 .6 .62 .35 230 Snubbed .9 .6 .58 .32 240 Snubbed .8 .6 .54 .30 340 Tandem or Dual .5 .4 .29 .143 360 Tandemor Dual .5 .4 .26 .125 380 Tandem or Dual .5 .3 .23 .108 400 Tandem or Dual .5 .3 .21 .095 420 Tandem or Dual .4 .3 .19 .084 440 Tandem or Dual - - .17 .074 460 Tandem or Dual - - .15 .064 480 Tandem or Dual - - .14 .056

Additional tension must be added to the Effective Belt Tension to prevent belt slippage on the drive pulley. This is called Slack Side Tension (TS).

TS = D x TE
Drive Factor - Table B

Total tension herein called Operating Tension (TO), sometimes called Allowable Working Tension, is the value used to select the reinforcement ply combinations.

TO = TE + TS/W
TE = Effective Belt Tension at drive
TS = Slack Side Tension
W = Belt Width (inches)

The next step is to select the proper reinforcement (usually fabric) combinations. A number of alternatives are usually available, and the final selection is narrowed by the following considerations:

1. Flexibility to negotiate the pulleys. The minimum recommended pulley diameters for each fabric -- the number of plies combination must be considered at the percent of rated tension of the combination. If this is disregarded, service life will be shortened by ply delamination, splice failure, and tracking problems. See Table C, page 11-5.
2. Troughability. Eliminate combinations that will not allow normal belt contact with carrying idlers, including transition areas, while belt is empty. A belt with inadequate transverse flexibility will result in poor training and tracking which will cause edge wear, spillage, poor loading, and early belt failure. See Tables D1 and D2 on page 11-6.
3. Impact Resistance. The final selection must be rated to handle the lump weights and the weight per lineal foot of the material. Loading conditions will vary and must be considered. Your selection must be rated for the condition or the belt will be beaten into premature failure. See Tables E1, E2, and E3 page 11-8.
4. Load Support. The final selection must be capable of resisting the load weight at the juncture of the center support idler and the troughing idlers. The belt carcass will break down and split longitudinally in this area if it is loaded beyond its capacity to support the load. See Table F1 page 11-10.

The values of the belt carcass to pass the above consideration should be available in the conveyor belt manufacturer reference manuals or printed information for belt selection.

The final selection of the alternate combinations should be made by considering costs and availability from a reliable source.

MOTOR HORSEPOWER (HP)

To determine the required motor horsepower given the calculated Effective Belt Tension (TE) and belt speed (fpm).

HP = TE x fpm/33,000

To determine maximum Total Tension (TO) that a system can generate given the nameplate horsepower of drive, Drive Factor (D), width of belt (inches), and belt speed (fpm).

TO-MAX = .9 HP x 33,000 x (1+D)/W x S
HP = Nameplate HP rating
D = Drive Factor (see Table B)
W = Belt Width (inches)
S = Speed of Belt (ft./min.)

NOTE:
If oversized motor is used, there is always the potential of surge loading that could over stress the belt system.