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Belt conveyor capacity and power

Enter material, width, speed and profile to see how many tons per hour the belt carries, whether speed and incline suit the material and how much power the drive needs.

Pre-sizing and estimating tool: results do not replace design, calculations or reports signed by a licensed professional, nor verification against the applicable codes and standards.

Pre-sizing
Material
Belt and idlers

A 4-ply EP fabric belt (about 360 PIW) with 3/16 + 1/16 in covers is about 3 lb/ft². Steel cord: 5 to 9 lb/ft².

Profile
Drive
—Maximum belt capacity
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Load cross-section

Belt on the idlers, trapezoidal base and arc-shaped surcharge with the CEMA edge distance.

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Capacity versus speed

Full section for the chosen width and the neighboring widths; the dashed line is the design capacity.

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Next step

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Method, assumptions and references

Equations used

Section (CEMA): c = 0.055 · B + 0.9 in; center roll b = 0.371 · B + 0.25 in; s = (B − 2c − b) ÷ 2; A_base = (b + s · cos β) · s · sin β; W = b + 2 · s · cos β; A_surcharge = W² ÷ (4 · sin² δ) · (δ − sin δ · cos δ)
Capacity: Q = 3.6 · A · v · ρ · k (Q in t/h, A in m², v in m/s, ρ in kg/m³; k = ISO 5048 incline factor)
Resistances (ISO 5048 / DIN 22101): F_U = C · f · L · g · [m_R + (2 · m_G + m_L) · cos δ] + H · g · m_L + F_cleaners; m_L = Q ÷ (3.6 · v); F_cleaner = 0.6 · 60 kPa · (0.01 m · B)
Tensions: T2 = max[F_U ÷ (e^(μ·φ) − 1); a_o · (m_G + m_L) · g ÷ (8 · 0.01)]; T1 = F_U + T2; P_pulley = F_U · v; P_motor = P_pulley ÷ η

Assumptions and limits

  • Three equal-roll idlers (or flat belt), centered load with the CEMA standard edge distance. Maximum speed follows CEMA Table 4-1 by width and material type; friable materials use a practical 250 to 400 fpm limit.
  • Idler rotating mass estimated at 13.5 kg per meter of width per carrying set and 10 kg per meter per return roll. T2 takes the larger of pulley traction and 1% sag between carrying idlers, without return-side resistance.
  • Long skirtboards, trippers, plows, curves, starting and braking are not included. The suggested EP rating uses a safety factor of 10 on T1; confirm with the belt manufacturer.

Standards and technical documents

  • CEMA: Belt Conveyors for Bulk Materials, 7th ed. (2014), chapters 4 (capacity and speed) and 6 (belt tension and power)
  • ISO 5048:1989: Continuous mechanical handling equipment — Belt conveyors with carrying idlers — Calculation of operating power and tensile forces
  • DIN 22101:2011: Continuous conveyors — Belt conveyors for loose bulk materials — Basis for calculation and dimensioning
  • ISO 251:2012: Conveyor belts — Widths and lengths
  • ISO 14890:2013: Conveyor belts — Specification for rubber- or plastics-covered conveyor belts of textile construction

U.S. regulations

  • ASME B20.1: Safety Standard for Conveyors and Related Equipment
  • OSHA 29 CFR 1910.212 (machine guarding) and 1910.147 (control of hazardous energy)
  • MSHA 30 CFR 56.14107 and 56.14109: moving machine parts and conveyor stop cords at surface mines

Frequently asked questions

How do I calculate belt conveyor capacity?

Multiply the load cross-section area by belt speed and bulk density. A 30 in belt on 35° idlers with a 25° surcharge has about 0.72 ft² of section; at 400 fpm with 87 lb/ft³ limestone it carries roughly 740 short tons per hour.

What is the maximum belt conveyor speed?

It depends on width and material. CEMA lists 350 to 600 fpm for hard abrasive ores and rock up to 60 in wide, and up to 800 to 1,000 fpm for grain on wide belts. High speed means more dust, wear and degradation of friable materials.

How do I estimate conveyor motor horsepower?

Add idler and belt friction (C · f · L · g · masses), material lift (H · g · m_L) and belt cleaners, then multiply by speed. For 400 short tons per hour over 500 ft with 40 ft of lift at 400 fpm, that is about 28 hp at the pulley and 30 hp at the motor.

What is the surcharge angle?

The slope of the material surface on the moving belt, usually 5° to 15° below the angle of repose. Higher values increase the usable section; 20° to 25° is common for crushed materials.