Corrosion Resistant Belt Conveyor for Large Conveying Capacity and Continuous

Belt conveyors are widely used in the chemical, metallurgical, coal mining, hydropower, and construction materials industries. They are suitable for conveying various bulk materials, including lump and granular materials.

In municipal wastewater treatment applications, belt conveyors are commonly used together with mechanical screens or sludge dewatering equipment to transport screenings or dewatered sludge.

The belt conveyor mainly consists of a frame, conveyor belt, idlers, drive unit, tensioning device, return pulleys, braking device, and belt-cleaning device.

The equipment adopts a continuous trough-type belt conveying system. Material discharged from a mechanical screen or sludge dewatering machine falls onto the conveyor belt. Driven by the motorized pulley, the material is transported from one end of the conveyor to the other. At the discharge end, the material falls into a waste container for subsequent handling or disposal.

• Reliable operation, large conveying capacity, and long conveying distance. The conveyor supports continuous operation as well as material loading and unloading at multiple points.
• The drive unit adopts an oil-cooled motorized pulley with an IP55 protection rating. It features a compact structure, occupies little space, and is easy to maintain.
• A screw-type tensioning device is used to ensure the safe, reliable, and efficient operation of the conveyor belt.
• The conveyor belt is made of nitrile rubber and joined by vulcanization. It is easy to clean, corrosion-resistant, and has a long service life.
• Screening-retaining plates are installed on both sides of the upper troughing idlers to prevent screenings and wastewater from spilling, helping to maintain a clean working environment.
• The equipment is easy to operate, resistant to blockage, and convenient to maintain. It can be installed horizontally or at an inclined angle, making it an ideal solution for conveying screenings.
• The equipment can be interlocked with associated machinery for coordinated operation. It may also be supplied with an independent local control cabinet.

The conveyor belt is the main component of a belt conveyor. It serves as both the load-carrying element and the traction element, transporting materials and transmitting the pulling force.

The belt runs along the entire length of the conveyor and is therefore used in a relatively large quantity. Common belt types include standard PVC belts, food-grade PU belts, anti-slip belts, belts designed for logistics conveying, PTFE belts, and high-temperature-resistant belts.

Idlers support the conveyor belt and rotate as the belt moves. Their main functions are to support the belt, reduce running resistance, limit belt sag within the specified range, and ensure stable belt operation.

According to their functions, idlers can be classified as:

• Troughing idlers
• Flat return idlers
• Impact idlers
• Self-aligning idlers

Idler diameters normally follow imperial dimensions, but customized sizes are also available. Commonly used diameters include 25.4 mm, 38.1 mm, 50.8 mm, and 76.2 mm.

The drive unit provides power for the belt conveyor. The motor drives the drive pulley through a coupling and gearbox. Friction between the drive pulley and the conveyor belt causes the belt to move.

The tensioning device ensures that the conveyor belt maintains sufficient tension to generate the required friction between the belt and the pulley. It also limits belt sag between the supporting idlers, thereby ensuring the normal operation of the belt conveyor.

Common tensioning systems include screw-type tensioning devices and gravity take-up devices.

A screw-type tensioning device uses two adjusting screws. When the screws are rotated, the bearing housings of the tensioning pulley move accordingly. This type of device has a relatively short adjustment stroke and cannot maintain constant belt tension. It is generally suitable for short-distance, low-power conveyors.

A gravity take-up device can maintain relatively uniform belt tension continuously. The suspended counterweight automatically adjusts according to operating conditions, effectively maintaining constant tension. It is generally suitable for long-distance, high-power conveyors.

The bend pulley changes the direction in which the conveyor belt travels, enabling the belt to form a closed continuous loop.

It may serve as the tail pulley of the conveyor or as the take-up pulley in the tensioning system. It can also redirect the belt through different angles according to the conveyor layout.

Bend pulleys are generally manufactured from either cast iron or welded steel plate. Since rubber lagging provides elasticity and helps prevent material buildup on the pulley surface, bend pulleys are available in both rubber-lagged and non-lagged versions.

For an inclined belt conveyor operating under load, if the inclination exceeds a certain angle, the conveyor belt may run backward when the motor is switched off or loses power. This can cause material accumulation and spillage and may even result in belt breakage or mechanical damage.

To prevent accidents caused by reverse movement during the shutdown of a heavily loaded conveyor, a braking or backstop device is normally installed.