Aggregates Manager Digital Magazine
Issue link: http://read.dmtmag.com/i/708006
AGGREGATES MANAGER / July 2016 31 A ggregate producers spend millions of dollars every year maintaining conveyor systems. Oftentimes, conveyor design does not provide the means for ease of maintenance, and, as a result, maintenance may not be performed correctly, on time, or at all. This eventually leads to a greater risk of component failure and a resulting loss of production. Designing a conveyor to be mainte- nance friendly means providing adequate provisions for necessary service from the onset. It also means eliminating problems such as inadequate component spacing, inaccessible positions, and other non-re- pairable confi gurations. Material characteristics When designing a conveyor, the type of material to be conveyed is the fi rst item to be taken into consideration. The fl owability of a material affects the size of the cross section of material load that can be carried on a given belt width. Flowability is affect- ed by material characteristics such as: size and shape of the fi ne particles and lumps, roughness, or smoothness of the material particle surface; the proportion of fi nes and lumps present; and material moisture con- tent. Considerations should also be given to the weight per cubic foot of material, abrasiveness, and temperature. Belt width, speed, and capacity For a given speed and material density, the wider the conveyor belt, the higher the ca- pacity of the conveyor. A belt must be wide enough so that the combination of fi nes and lumps do not push the lumps too close to the edge of the belt. Conveyor belt speeds depend upon the material characteristics, the capacity desired, and belt tensions. Heavy material with sharp edges should be conveyed at moderate speeds. The sharp edges will cause wear to the belt, particularly if the loading velocity of the material in the direction of belt travel is lower than the belt speed. Light, powdery materials must also be conveyed at lower speeds to reduce dust particles, especially at loading and discharge points on the conveyor. Frag- Proper system design reduces operating costs and improves an operator's ability to properly perform maintenance.