Optimizing Skirtboard Design: Enhancing Conveyor Efficiency and Reducing Material Loss
The distance between the two sides of the skirtboard is typically determined by the belt capacity requirements. Unfortunately, the space necessary to create an effective seal on the outside of the skirtboard is often overlooked.
It is crucial to design the system with adequate "free-belt" distance (the space between the outside of the skirtboard and the outer edge of the belt). This factor should not be underestimated. Conveyor designers must always consider the impact of potential belt wander on the ability to seal effectively between the stationary skirtboard system and the moving belt. By maintaining the maximum possible "free-belt" distance, designers can significantly reduce common spillage and dust issues associated with transferring bulk materials between conveyors.
Moreover, maintaining the correct "free-belt" distance to accommodate a sealable skirtboard system is further enhanced by ensuring proper belt support under the skirtboard and installing an effective skirtboard-sealing system. The effective belt width, which represents the width of a troughed belt, is crucial here. It differs from the carrying width (the distance between skirtboards) and is measured horizontally across the troughed conveyor belt, parallel to the bottom roller.
Various standards, such as those from the Conveyor Equipment Manufacturers Association (CEMA) and the Deutsches Institut für Normung (DIN22101), offer formulas for setting the distance between skirtboards and establishing the "free-belt" edge distance.
Best practice dictates that skirtboards should be positioned with a minimum of 115 millimeters (4.5 inches) of actual belt width on each side of the conveyor belt to ensure adequate "free-belt" edge for applying edge seals and to allow for belt mistracking tolerance.
This edge distance should be increased to a minimum of 150 millimeters (6.0 inches) when using five roll catenary idlers in the load zone, compensating for additional belt misalignment typical of belts using catenary idlers.
It's also important to verify the skirtboard width to ensure that the height of the material bed exiting the skirting area, along with the material's angle of repose, does not create spillage issues.