Conveyor Belt Calculator

A belt conveyor splits into two nearly independent questions: how much material the moving cross-section carries, and what force is needed to drag it along. Capacity is purely kinematic - loaded profile area A in square metres times belt speed v in metres per second times 3600 gives cubic metres per hour, and multiplying by bulk density gives tonnes per hour. Bulk density, not solid density, is the correct input: crushed stone runs about 1600 kg/m3, coal 800 to 1000, sized gravel up to 2400. The profile area itself depends on belt width, the troughing angle of the idler set (20, 35 and 45 degrees are standard) and the surcharge angle the material forms as it rides. Power splits into two physically distinct terms. Lift power is exact - material mass per metre times 9.81 times vertical rise - and cannot be engineered away. Friction power is empirical, lumped into a coefficient f absorbing idler rolling resistance, belt flexure and rim drag, typically 0.02 indoors to 0.03 or more for dusty outdoor plant. Total resistive force times belt speed gives kilowatts at the pulley; dividing by drive efficiency near 0.85 to 0.92 gives the motor rating. Practical bounds apply: belt speeds run 0.5 to 6 m/s, with abrasive rock near 1.0 to 2.5; smooth belts hold bulk material only to about 15 to 18 degrees of incline; and lump size should stay under a third of belt width. Acceleration, cleaner and skirtboard drag, and take-up tension are omitted here.

Continuous belt handling of bulk solids became industrial in the 1890s. Thomas Robins, working from 1892 on ore and coal handling for Thomas Edison's mining ventures in New Jersey, developed rubber-covered belting and the troughed idler arrangement that lets a flat belt form a carrying profile, work recognized at the 1900 Paris Exposition. Sandvik of Sweden produced steel-band conveyors from 1901, and in 1905 the mining engineer Richard Sutcliffe introduced belt conveyors underground in British coal mines, an application that reshaped longwall mining by removing the haulage bottleneck at the face. Design practice was codified rather than invented. The Conveyor Equipment Manufacturers Association formed in the United States in 1933, and its handbook Belt Conveyors for Bulk Materials, first issued in 1966 and now in its seventh edition, standardized the tension, idler and power methodology most English-language design still follows, including the tables relating belt width, trough angle and surcharge angle to carrying area. The German standard DIN 22101 developed a parallel formulation used widely in Europe, differing mainly in its treatment of friction and secondary resistances. Later editions absorbed changes in the equipment itself, notably synthetic and steel-cord carcasses replacing cotton plies, which raised working tensions enough to make single-flight overland conveyors of many kilometres feasible.