What Is a Tubular Drag Conveyor?

Conveyor belts for load and return branches are rolled into a tubular belt conveyor. It is a new type of conveyor with both pipeline and belt conveyors. It has a large conveying inclination, small curvature radius, small cross-sectional area of the fuselage, and three-dimensional space curved conveying. , Management and other advantages, but the block size of the material is limited by the width of the conveyor belt, and should not be used in situations where the transmission line is short and there are multiple places to receive or discharge (except for the guide roller and roller tubular belt conveyor). Used to transport coal, ore, grain, cement, pulp and concrete and other block and powder materials. ^[1]

A tubular belt conveyor with a conveyor suspended by a special spreader (Figure 1). According to the hanging method, it can be divided into three types: hanging roller type, guide roller type and pulley clamping groove type.

The conveyor belt is surrounded by the rollers installed on the end plate of the frame, curled into a tube, and the conveyor belt is overlapped to achieve a tubular closed conveyor. The machine can be divided into three types: self-enclosed, round end disc type and rectangular end disc type (Figure 2).

(1) Self-enclosed tubular belt conveyor The conveyor belt is a circular rubber pipe cut along the longitudinal direction. It can be closed into a circular tube by itself in the operating area, and it is only a flat conveyor that is unfolded in the receiving area and the unloading area. Figure 2a). The carrying branch of the conveyor has 4 rollers. Two rollers arranged in a V shape are used to support the weight of the conveyor belt and the material. The two parallel rollers on the side are used to prevent the conveyor belt from spreading to the sides under the action of the material. open. The straight section of the return branch uses two V-shaped rollers to support the conveyor belt facing down. There are four rollers in the curved section, two of which are V-shaped rollers supporting the conveyor belt, and the other two side rollers parallel to each other are used to bear the radial force generated by the belt tension.

(2) The round end disc tubular belt conveyor has a total of 12 supporting rollers for the carrying and returning branches. It is divided into two groups and installed on the two planes of the round end disc to form two regular hexagonal sections (next page). Figure 2b). The idler rollers are arranged alternately with each other to avoid abrasion caused by the contact between the conveyor belt and the end face of the idler roller. If the centerline of the conveyor frame is not consistent with the direction of the curved line, the end disk position can be adjusted to make the conveyor run normally.

(3) The rectangular end disc tubular belt conveyor is the most widely used and the most mature technology in the tubular belt conveyor. There are 12 supporting rollers in the bearing and return branches, which are divided into two groups and installed on the two planes of the rectangular end plate to form two regular hexagonal sections (Figure 2c on the next page). The supporting rollers are arranged in the same vertical plane. In the receiving area, the conveyor belt is straight at the drum, then gradually transitions to a U-shape, and finally becomes a tube. The process is reversed in the unloading area. Because the conveyor belt is surrounded by 6 rollers to form a tube shape, in addition to the running resistance, there are also tube resistance, rigid resistance and bending resistance, so the power required by the conveyor must be increased. The conveyor can be bent. For nylon core conveyor belts, the radius of curvature must be greater than 300 times the pipe diameter; for steel wire core conveyor belts, the curvature radius must be greater than 700 times the pipe diameter. When the loading area of the material exceeds 75% of the cross-sectional area of the round pipe and the maximum block size is less than 1/3 of the pipe diameter, the conveyor can operate normally.

The longest rectangular end-disc tubular belt conveyor in the world transports coal at Utah Fuel Company, USA, with a total length of 3466m; a transport inclination of 10 °; a transport speed of 250m / min; a transport capacity of 1400t / h; The pipe diameter is 400mm. ^[2]