Dry Bulk Conveyors

Useful Transfer Point Tips

A transfer point is any point where material is loaded onto or unloaded from a conveyor. Preventing spillage at any given transfer point is imperative as the cost reductions from eliminating spillage at just a single transfer point are
significant.

It is estimated that 85% of conveyor maintenance is a result of fugitive material, says the government’s Mining Safety and Health Research (MSHA) group who has assembled some figures on the labor costs of one person spending one hour per shift to clean spillage at one transfer point.

The labor cost for one year exceeds $22,000, and over a ten-year period costs top $220,000! Also consider that the elimination of 5,200 hours of repetitive manual material handling over a ten-year period means fewer injuries and worker’s compensation claims. Properly designed transfer points also mean cost reductions resulting from less equipment damage, reduced conveyor maintenance and increased conveyor uptime.

Ideally, a transfer point should be designed to load the belt in the center and at a uniform rate. Also, transfer points should be engineered to reduce the impact of material falling on the belt. Loading zone impacts cause wear and damage to the conveyor belt, weakening the belt carcass. To reduce impact at transfer points, impact cradles can be positioned under the conveyor. Or, impact idlers may be used at a transfer point. These are troughing idlers that have rubber-cushioned rollers to absorb impact.

Also, it’s important that skirtboards, and loading and discharge chutes be selected and installed to match the characteristics of the material as well as the conveyor. For example, the Conveyor Equipment Manufacturer’s Association (CEMA) suggests that the width of a loading chute should be no greater than two-thirds the width of the receiving belt. The inside width of the loading chute should be at least two-and-a-half to three-times the largest dimension of uniformly sized lumps, when they represent a considerable percentage of the material flow. Where lumps and fines are mixed, the inside width of the chute may be as small as two times maximum lump size.