3 KudoZ points awarded for this answer. Comment: "Получил пояснения от клиента: Material should be released into the conveyor at a controlled rate, not too rapidly for the conveyor to take away all material that is allowed into it. If material is allowed to fill the trough to a greater depth, it is dragged to the "tail section" by the upper chain, because the lower portion is completely filled. When material reaches the tail section, if in-flow persists, it continues to fill the upper portion of the trough, on top of the normal load. When the conveyor contains material that fills both the lower and at least part of the upper run of chain, it creates a "plug" of material. At some point, several events may occur: the friction and extra weight of material may cause the external drive mechanism to overheat or fail; or, the conveyor chain may break; or, flites and metal attachments on the chain may bend or break loose; or, the trough cover may dislodge."