types of idler in belt conveyor

Types of Idlers in Belt Conveyors

Belt conveyors are an essential component in material handling operations across various industries, enabling the efficient transport of materials over varying distances. At the heart of a belt conveyor system is the idler, a crucial element that supports the conveyor belt, ensuring it runs smoothly and efficiently. Understanding the different types of idlers and their specific applications is vital for optimizing conveyor performance and lifespan.

1. What are Idlers?

Idlers are the rotating rollers that support the conveyor belt and help maintain its tension. They are positioned at various points along the length of the conveyor to facilitate smooth belt movement, reduce wear, and minimize energy consumption. Different types of idlers are designed for specific applications based on factors such as load capacity, material being transported, and environmental conditions.

2. Types of Idlers

A. Carrying Idlers

Carrying idlers are designed to support the weight of the material being transported. They are typically found in the middle section of the conveyor and are arranged in a set of three rollers to create a stable trough shape for the belt, which helps contain the material.

- Flat Carrying Idlers These idlers consist of three horizontal rollers and are suitable for transporting bulk materials where there is minimal risk of spillage. However, they are not as effective in containing materials that might shift during transportation.

- Trough Carrying Idlers Trough idlers have rollers that are angled to form a V shape, creating a trough that holds the material securely on the belt. This design is particularly useful for bulk materials like grains, ores, and aggregates, where control over material spillage is critical.

B. Return Idlers

Return idlers are positioned at the bottom of the conveyor belt, supporting the return side of the belt as it moves back to the loading area. Their role is crucial in keeping the belt properly aligned and reducing friction against the supporting frames.

- Flat Return Idlers These consist of horizontal rollers that provide simple support along the return path. While they are effective for less abrasive materials, they may wear out more quickly under heavy loads.

- Trough Return Idlers Similar to trough carrying idlers, these have an angled design that helps to maintain belt alignment and prevent spillage on the return side. They are essential in scenarios where the material may stick to the belt or where there is a risk of contamination.

C. Impact Idlers

Impact idlers are specifically designed to support the belt at loading points where heavy materials are dropped onto the belt. They are equipped with a mechanism to absorb some of the impact force, thereby protecting the conveyor belt and shortening maintenance intervals.

- Heavy Duty Impact Idlers These idlers are constructed from durable materials and are reinforced to withstand significant impact forces, making them suitable for high-capacity conveyor systems in mining and heavy industry.

D. Guide Idlers

Guide idlers are used to maintain the proper alignment of the conveyor belt. They are often installed at the head and tail pulleys or in areas where the conveyor is prone to lateral movement.

- Training Idlers These are a subset of guide idlers that help adjust the belt's position during its operation. They can be adjusted to nudge the belt back into proper alignment whenever it begins to drift off course.

3. Choosing the Right Idler

Selecting the right type of idler is vital for ensuring the efficiency and reliability of a belt conveyor system. Factors to consider include

- Material Type Understanding the characteristics of the material being transported, such as granule size, weight, and abrasiveness, can influence the idler choice.

- Conveyor Length and Angle Longer or steeper conveyors may require stronger or more specialized idlers to support the additional stresses on the system.

- Operating Conditions Environmental factors such as temperature, humidity, and the presence of dust or corrosive substances will also affect idler material selection.

Conclusion

Idlers are a fundamental part of the belt conveyor system, playing a crucial role in maintaining performance and efficiency. By understanding the different types of idlers—carrying, return, impact, and guide—and their specific applications, operators can make informed decisions on the right idler for their needs. Proper selection and maintenance of idlers not only enhance the longevity of the belt conveyor system but also contribute to improved productivity and reduced operational costs.