New, enclosed conveying systems cover materials and allow producers to move them at steeper inclines or around other plant equipment, thus eliminating the need to acquire more property or expand a facility. Additional benefits include less spillage, less maintenance on idler bearings, greater dust control, and often greater carrying capacity without a notable increase in energy consumption. Because they eliminate the need for additional support structures, drive motors and dust-collection equipment at transition points, these systems may save money initially compared with multiple open conveyor systems.One type of sandwich system keeps tension on material contained between an inner carry belt and an outer cover belt. Another system uses patented live-shaft wing rollers to form and keep tension on the carry and cover belts, forming a sandwich. Sandwich systems can move material at an incline up to 90 degrees, enabling the producer to incline most of the conveyor's length along the exterior of the production facility or inside the plant. Another manufacturer's system, a foldover system, employs sets of hold-down idlers, positioned above the belt, and standard trough idlers supporting the belt. Near the tail pulley, the belt folds around the chute that loads material, forming the belt into a u-shape for loading. A European system recently introduced in North America for interior applications uses a special v-shaped belt with steel strands at the edges. A layer of rubber covers the strands to form raised edges. The belt folds in the middle, and the edges interlock between top-mounted idler rollers.

Keywords: enclosed, conveyor, Continental Conveyor, sandwich, steep, incline, Elevayor, Imperial Technologies, SICON, Fairfield Engineering