Large Angle Belt Conveyor

A large-angle belt conveyor is a special conveying equipment that uses corrugated sidewalls and cross diaphragms to achieve large-angle material conveying. By combining corrugated vertical sidewalls and box-shaped cross-cleats on a flat rubber conveyor belt, the system can elevate materials at angles ranging from 0° to 90°. It is capable of transporting a wide variety of bulk materials, such as crushed stone, limestone, coal, sand, clay, sintered powder, wood chips, and grain. Compared to standard belt conveyors, this equipment offers 1.5 to 2 times the conveying capacity.

The steep-angle belt conveyor shares its basic components with standard belt conveyors, ensuring high versatility. Parts such as drive pulleys, idlers, tensioning devices, intermediate frame supports, tail frames, discharge hoppers, head covers, return-side belt cleaners, and safety devices are interchangeable with those of standard belt conveyors. This equipment can be selected as a direct alternative to the combined "standard conveyor plus bucket elevator" configuration, offering advantages such as a smaller footprint, reduced investment costs, and ease of layout.

Structural composition of the equipment

The biggest structural difference between a large-angle belt conveyor and a general belt conveyor lies in its corrugated sidewall conveyor belt.

(1) Corrugated Sidewall Conveyor Belt: This is the core component of the equipment, serving both traction and load-bearing functions. The corrugated sidewalls, transverse cleats, and base belt form a "box-like" container for the conveyed material, enabling steep-angle transport. While the base belt resembles a standard conveyor belt, it possesses greater transverse rigidity. The sidewalls are corrugated to allow the belt to navigate the convex and concave curved sections of the conveyor path; these corrugations may take the form of sine waves, square waves, or W-shapes. Transverse cleats are spaced at regular intervals on the base belt between the two sidewalls.

(2) Drive Unit: This provides the motive power for the conveyor and consists of a Y-series electric motor, a ZJ-type shaft-mounted speed reducer, and a wedge-type backstop.

(3) Drive Pulley: This is the primary component for power transmission; the conveyor belt operates via the friction generated between it and the drive pulley. Drive pulleys come in rubber-lagged and smooth-faced varieties; rubber lagging is used to increase adhesion between the pulley and the belt.

(4) Bend Pulley: Used to alter the direction of the conveyor belt's travel; it typically contacts the underside (non-load-bearing surface) of the belt.

(5) Idlers and Frame: These include various types such as flat impact idlers, parallel upper idlers, dual-roller lower idlers, and self-aligning idlers. The frame utilizes a "Z-shaped" configuration, dividing the machine into upper horizontal, lower horizontal, and inclined sections.

(6) Tail Tensioning Device: This allows for convenient tensioning of the conveyor belt, preventing slippage on the drive pulley and improving transmission efficiency.

(7) Belt Cleaners: These include head-section cleaners and return-strand cleaners, designed to remove material adhering to the conveyor belt.

Application scope of the equipment

Large-angle belt conveyors can be widely used in coal, grain, building materials, chemical, hydropower and metallurgical industries. In the coal industry, they facilitate the underground and surface transport of raw coal, clean coal, and coal gangue. In the grain industry, they are used for grain intake, discharge, and transfer. In the construction materials sector, they handle the transport of sand, gravel, aggregates, and cement. In the chemical industry, they convey raw materials for fertilizers and chemical powders. In the power industry, they serve coal-handling systems at thermal power plants. In the metallurgical industry, they are used to transport ore, mineral powder, and sintered fines.

Types of usable raw materials

Steep-angle belt conveyors are suitable for transporting various bulk materials with a bulk density of 0.5–2.5 t/m³. Typical materials include crushed stone, limestone, coal, sand, clay, sintered sand/powder, wood chips, and grain, with maximum lump sizes ranging from approximately 100 mm to 250 mm. For materials with special requirements—such as those involving high temperatures, acidity or alkalinity, oils, or organic solvents—specialized sidewall conveyor belts must be used.

The working principle of the equipment

The working principle of a large-angle belt conveyor is basically the same as that of a general belt conveyor. its unique feature lies in the use of a corrugated sidewall conveyor belt.

The specific operation is as follows: flexible, vertical rubber corrugated sidewalls are bonded to both sides of a flat rubber base belt, and transverse cleats—possessing specific strength and elasticity—are bonded between the sidewalls to form box-like compartments. Once loaded at the feed end, the material is confined within these "box-like" containers formed by the corrugated sidewalls, transverse cleats, and the base belt. Driven by the drive pulley, the conveyor belt runs continuously, carrying the material up the inclined section. The sidewalls prevent the material from spilling over the sides, while the cleats support the load, preventing it from sliding back down the incline. Upon reaching the top, the material is discharged through the discharge outlet under the combined influence of centrifugal force and gravity. This structural design enables the safe transport of materials at inclination angles ranging from 0° to 90°.

Equipment operating instructions

(I) Pre-start checks: Before operation, carefully inspect the conveyor belt for misalignment and ensure the load is properly positioned. Check that the gearbox oil level is normal and that all fasteners are secure. Inspect the area between the belt and the pulleys for any trapped material. Check the belt splice/joint for any abnormalities.

(II) No-load startup: High-angle belt conveyors must be started and stopped without a load; starting under load is strictly prohibited. When multiple conveyors are connected in series, they must be started sequentially in the direction opposite to the material flow.

(III) Operational monitoring: Closely monitor the equipment during operation to ensure normal functioning. Promptly address any factors causing belt misalignment. Reduce the material drop height to minimize impact on the conveyor belt. It is strictly prohibited to use tools to clean material adhering to the pulleys while the machine is running.

(IV) Shutdown procedure: Stop the conveyors sequentially in the direction of the material flow; stopping under load is strictly prohibited.

Equipment maintenance methods

(I) Routine Maintenance: During each shift, inspect the conveyor belt joints for abnormalities such as cuts or cracks. Check the top and bottom rubber layers of the belt and the sidewalls for wear. Inspect the rubber scraper of the cleaning device for excessive wear. Ensure all idlers rotate freely and promptly replace any that are seized or damaged.

(II) Periodic Maintenance: Regularly lubricate all bearings. Re-tighten all anchor bolts and cross-beam connection bolts. Repair or replace worn conveyor belts and other components. Periodically inspect the scraper device to ensure its surface remains smooth, thereby minimizing wear on the belt.

(III) Lubrication Management: Apply grease to drive unit bearings at specified intervals. Regularly check the oil level in the gear reducer and promptly top up or replace the gear oil.

Solutions to Equipment Problems

Conveyor belt mistracking: Address this by adjusting the tail pulley's adjustment screws, modifying tail-end pressure, adjusting the idler assembly, inserting shims at the idlers, or cleaning accumulated ore from the drive and tail pulleys. Additionally, an anti-mistracking alarm system is installed at the head frame to provide protective monitoring.

Conveyor belt slippage: Adjust the tensioning device to increase initial tension. Remove water or oil from the pulley surfaces. Utilize drive pulleys with rubber-lagged surfaces to enhance traction.

Sidewall damage: Inspect and replace damaged sidewall belts. Install debris removal devices at the feed inlet to eliminate hard objects. Select sidewall belt materials with superior wear and aging resistance.

Wear on skirt/hold-down components: Adjust the clearance between the hold-down rollers and the top of the skirt; modify the contact mode of the edge hold-down rollers from angled contact to parallel contact.