A drag conveyor is an enclosed conveyor often used where the elevation of the transported material changes. It can handle small materials as well as large objects which are moved by a chain guided through an enclosed trough. An industrial drag conveyor is one of the many types of conveyors used for moving bulk materials, and is suited for safely moving large amounts of agricultural, coal plant, and concrete materials. The types of drag conveyors used depend on the application, but the machines can be designed to many different specifications. Safety is always an issue for operators, so it is always important to follow the guidelines of a regulatory entity, such as the Conveyor Equipment Manufacturers Association (CEMA).
Inside of a drag conveyor, a linked chain runs along the length of a trough which is typically in the shape of a rectangle or square. The machine also includes a drive sprocket to loop the chain continuously through the trough. Materials are moved from one end to the other through the enclosure, so it does not spill or drop out along the way, and dust or other contaminants cannot get inside. These materials originate in a hopper before entering the conveyor, and are delivered to an outlet at the far end to receive the conveyed loads. Other parts of a drag conveyor include plates on the chain to guide the materials to the end, and a power source, such as a motor or engine, to power the chain’s drive system.
The design of the system has an impact on using a drag conveyor. Certain conveyors are built to move larger or smaller sized materials, or materials of a certain type. Loading also affects the design; some conveyors are loaded in line with other process equipment, while others may be loaded by truck. Elevation and distance are also factors that contribute to the design.
Used in many commercial and industrial sites, a drag conveyor can be found in grain silos, coal-fired power plants, and in concrete or brick manufacturing plants. Safety when using a drag conveyor means the user must pay attention to labels on the machinery, which should never be covered or removed. Standard warning labels created by the CEMA protect people from injury when operating the conveyor. It is also important to follow guidelines for loading the conveyor, turning the power off for maintenance, and for assembling the system in a sequence indicated by the manufacturer’s instructions.