Air-Supported Belt Conveyors

(not verified)
Posted in: , on 13. Sep. 2003 - 17:08


B.I.D. is a manufacturer of custom designed conveying systems. In addition to conveyors, B.I.D. makes truck dumpers, stackers, hoppers, chutes, and scalping screens. The primary customer to B.I.D. is the pulp and paper industry.

Through an agreement with Famson Pty Ltd. of Adelaide Australia, we can now design and build conveyors with Air-supported Belt technology. Famson has developed their technology over the past 15 years, with proven success in cement, woodchip, ore, fertilizer and grain handling.

Description of Air-Supported Belt Conveyors

The air-supported belt conveyor is a bulk handling belt conveyor that supports the belt on a film of air and eliminates the need for troughing idler rollers.

The air supported belt functions in a similar manner to a troughed idler conveyor except for the method of supporting the loaded belt. The system uses conventional head and tail sections, drives and return rollers. However, instead of having troughing idlers, the belt runs in a steel tube or trough that is rolled in a true radius. A small centrifugal blower forces air into a sealed plenum beneath the tube. From there the air passes through a special array of holes in the tube to form a thin film of air under the belt. The air-supported belt conveyor can also support the return belt as an option.

Illustration 1 is a cross section through a typical air-supported conveyor.

The air requirements are very low, running less than 7 kpa pressure (about 1 psi). Typically, one blower will handle up to 300 metres of conveyor.

Belting can be lighter and cheaper than with conventional conveyors, because there is no need for the belt to span the distance between troughing idlers and belt tensions are lower.

Belt life can be much longer since there is a significant reduction in friction on the belt. The belt flexing over idlers is eliminated and there are no sharp break points in the trough as at the typical idler junction point.

Belt tracking through the tube section is automatic and only the pulleys need adjustment.

Conveying at steeper inclines is possible because of the removal of the trough idlers. Belts with ribs can be used for even higher angles. Because of the increased cross-section, more material can be conveyed without increasing the belts speed or width.

Ideally the conveyors are supplied with an electrical control panel in which the blower and drive motors are interlocked. A single start/stop button operates the conveyor. When the button is depressed, the blower starts and builds pressure in the plenum. A preset air-pressure switch, mounted on the side of the plenum activates the drive when the required pressure is attained. Should the blower fail, or if the plenum should lose pressure for some other reason the air pressure switch automatically stops the drive motor and prevents it from overloading.

Units are available with open trough design, flat sealed covers over open trough design or using a full 360º tube. The full 360º tube design offers the best structural strength and weather-proofing, but has the tallest cross section so the half tube and cover will fit into places requiring a low profile system, because of space constraints.

Spans can be 20 metres without a truss.

B.I.D. Canada Ltd.

Patrick Sullivan


b.i.d.canada_news (JPG)

Write the first Reply