Stokman is the leading expert in heavy duty transport systems and specifically in the production of conveyor pulleys and rollers. In this blog, we explain the function of a conveyor pulley and specifically describe the vertical transport of bulk goods. We discuss concepts such as elevation height and elevation angle and explain a number of applications of our conveyor pulleys.
Conveyor pulleys not only determine the shape and length of a conveyor belt, they also serve as turning points and provide the drive of the belt.
The conveyor belt carries the material and passes around the pulleys and rollers as a loop. The rollers carry the belt from pulley to pulley and the pulleys guide, tension and drive the belt. At the beginning and end of the conveyor bed is a pulley, which is also the turning point of the belt.
Sometimes a conveyor belt goes in one straight line from point A to point B. But the terrain over which the material has to be transported is not always flat and accessible in one straight line. In many cases, the conveyor belt therefore has to bridge a height difference.
For example, vertical transport is necessary for the storage of bulk goods in high piles on an open site, or to transfer material to another conveyor belt or machine for loading a ship, silo or railway wagon and for longer conveyor belt trajectories.
Vertical transport is also called elevation. Conveying bulk material upwards requires more energy; this is influenced by 6 factors:
The elevation height is the difference in height that the conveyor belt has to bridge between the lowest and highest points of the installation. The length of the conveyor belt is the length from start to finish. The elevation height and length of the conveyor belt determine the elevation angle, but there are limitations.
There is a maximum elevation angle for each installation and the bulk goods it transports. If the elevation angle is too great, the conveyor belt becomes too steep and the bulk goods will slide down due to gravity.
The material is key in defining the maximum elevation angle, especially with a smooth conveyor belt with no profile. For example, damp material can be carried upwards at a steeper incline than dry sand or gravel. For a smooth conveyor belt, the maximum elevation angle is 15 to 16 degrees on average.
The desired capacity will also influence the design of an inclined conveyor system, because like the elevation height and length, it affects the required driving force.
A vertical conveyor with a greater elevation height requires more drive power than a horizontal conveyor with a comparable capacity and length.
To drive the conveyor system, we need pulleys, specifically a drive pulley. Depending on the aforementioned factors, we add one or more drive pulleys and make a choice between hydraulic or electric drive.
Stokman pulleys are primarily used in heavy duty conveyor systems. These are transport systems with high transport capacities of up to 6000 tonnes per hour and belt speeds of up to 6 metres per second. Our pulleys are highly suited to operation over a long period of time in these often heavily contaminated environments.
For example, our pulleys are used in transhipment terminals for iron ore, coal, sand and gravel, for biomass at power stations and in various maritime applications such as dredgers, cable-laying vessels, fallpipe vessels and bulk carriers with conveyor systems on board. We always custom build our pulleys for your application and transport system.
Our pulleys for conveyor belts are produced in our factory in Raamsdonksveer, are custom-built and are always manufactured to the very high standards for which Stokman has been known for almost 100 years. If you would like to know more about our pulleys, rollers or you have any questions about the transport of bulk goods, please contact us at email@example.com.