Conveyor Belt

Verified Timeline

Lore & Background

Primitive conveyor belts have been in use since the 19th century. In 1868, an English shipwright Joseph Thomas Parlour from Pimlico patented a grain elevator with a conveyor belt while Illinoisan Charles Denton of Ames Plow Co. patented a reaper with a belt "conveyer". By the 1880s conveyor belts were used in American elevators, sugarcane mills and sawmills, as well as British maltings. In 1892, Thomas Robins began a series of inventions which led to the development of a conveyor belt used for carrying coal, ores and other products. In 1901, Sandvik invented and started the production of steel conveyor belts. In 1905, Richard Sutcliffe invented the first conveyor belts for use in coal mines, which revolutionized the mining industry. In 1913, Henry Ford introduced conveyor-belt assembly lines at Ford Motor Company's Highland Park, Michigan factory. In 1972, the French society REI created in New Caledonia the longest straight-belt conveyor in the world in that moment, at a length of 13.8 km (8.6 miles). Hyacynthe Marcel Bocchetti was the concept designer. The longest conveyor belt is that of the Bou Craa phosphate mine in Western Sahara (1973, 98 km in 11 sections). The longest single-span conveyor belt is at the Boddington bauxite mine in Western Australia (31 km). In 1957, the B. F. Goodrich Company patented a Möbius strip conveyor belt, that it went on to produce as the "Turnover Conveyor Belt System". Incorporating a half-twist, it had the advantage over conventional belts of a longer life because it could expose all of its surface area to wear and tear. Such Möbius strip belts are no longer manufactured because untwisted modern belts can be made more durable by constructing them from several layers of different materials. In 1970, Intralox, a Louisiana-based company, registered the first patent for all plastic, modular belting.

In Their Own Story

The longest belt conveyor system in the world is in Western Sahara. It was built in 1972 by Friedrich Krupp GmbH (now thyssenkrupp) and is 98 km (61 miles) long, from the phosphate mines of Bu Craa to the coast south of El-Aaiun. The longest conveyor system in an airport is the Dubai International Airport baggage handling system at 63 km (39 miles). It was installed by Siemens and commissioned in 2008, and has a combination of traditional belt conveyors and tray conveyors.

Reader's Guide

Belt conveyors are the most commonly used powered conveyors because they are the most versatile and the least expensive. Products are conveyed directly on the belt so both regular and irregular shaped objects, large or small, light and heavy, can be transported successfully. Belt conveyors are also manufactured with curved sections that use tapered rollers and curved belting to convey products around a corner. These conveyor systems are commonly used in postal sorting offices and airport baggage handling systems. Belt conveyors are generally fairly similar in construction consisting of a metal frame with rollers at either end of a flat metal bed. Rubber conveyor belts are commonly used to convey items with irregular bottom surfaces, small items that would fall in between rollers (e.g. a sushi conveyor bar), or bags of product that would sag between rollers. The belt is looped around each of the rollers and when one of the rollers is powered (by an electrical motor) the belting slides across the solid metal frame bed, moving the product. In heavy use applications, the beds in which the belting is pulled over are replaced with rollers. The rollers allow weight to be conveyed as they reduce the amount of friction generated from the heavier loading on the belting. The exception to the standard belt conveyor construction is the sandwich belt conveyor. The sandwich belt conveyor uses two conveyor belts, instead of one. These two conventional conveyor belts are positioned face to face, to firmly contain the items being carried in a "sandwich-like" hold. Belt conveyors can be used to transport products in a straight line or through changes in elevation or direction. For conveying bulk materials, over gentle slopes or gentle curvatures, a troughed belt conveyor is used. The trough of the belt ensures that the flowable material is contained within the edges of the belt. The trough is achieved by keeping the idler rollers in an angle to the horizontal at the sides of the idler frame. A pipe conveyor is used for material travel paths that require sharper bends and inclines up to 35 degrees. A pipe conveyor features the edges of the belt being rolled together to form a circular section like a pipe. Like a troughed belt conveyor, a pipe conveyor also uses idler rollers. However, in this case, the idler frame completely surrounds the conveyor belt helping it to retain the pipe section while pushing it forward. In the case of travel paths requiring high angles and snake-like curvatures, a sandwich belt is used. The sandwich belt design enables materials carried to travel along a path of high inclines up to 90-degree angles, enabling a vertical path as opposed to a horizontal one. This transport option is also powered by idlers. Other important components of the belt conveying system apart from the pulleys and idler rollers include the drive arrangement of reducer gear boxes, drive motors, and associated couplings, scrapers to clean the belt, chutes for controlling the discharge direction, skirts for containing the discharge on the receiving belt, take up assembly for "tensioning" the belt, safety switches for personnel safety and technological structures like stringer, short post, drive frames, pulley frames make up the balance items to complete the belt conveying system. In certain applications, belt conveyors can also be used for static accumulation or cartons.

Did You Know?

• The longest belt conveyor system in the world is 98 km (61 miles) long, built in 1972 by Friedrich Krupp GmbH for the Bou Craa phosphate mine in Western Sahara.
• In 1913, Henry Ford introduced conveyor-belt assembly lines at Ford Motor Company's Highland Park, Michigan factory.
• The B. F. Goodrich Company patented a Möbius strip conveyor belt in 1957, which had a half-twist to expose all surface area to wear, but such belts are no longer manufactured.
• The highest strength class conveyor belt installed is made of steel cords with a strength class of 10,000 N/mm (57,000 lbf/in) and operates at Chuquicamata mine in Chile.
• The longest single-span conveyor belt is at the Boddington bauxite mine in Western Australia, measuring 31 km.