Conveyors are used to move products from one machine to another, from supply vehicles into a process, or from finished product storage to vehicles for delivery. A feed conveyor supplies products for cleaning or processing, or moves intermediate products to additional processing or handling equipment. These can be designed using belts, chains, rollers or other parts, but in all cases, they are devices that move raw materials.
The term "feed" is used in agriculture to identify animal food products, which might be plants such as hay, grains such as corn or oats, or dried animal-based feed. Many of these materials are moved in bulk, using trucks or railcars that transport large quantities in tanks. A feed conveyor is placed under the vehicle and a valve or gate is opened, allowing the feed materials to fall into the conveyor bin and move to storage tanks or directly to process equipment.
Feed conveyors can clean or shred materials as a first step in manufacturing. An example is a feed conveyor with a shredder attached that can grind up recycled paper used for making paperboard. Recycled metals are often sent through shredder conveyors that supply metal to re-melting operations. The feed conveyor may also be fitted with magnets to pick up iron-based metals and separate them from aluminum, or to remove metal wire and debris from recycled paper.
There are a number of ways to transport materials on a feed conveyor. A rubber belt reinforced with metal or fiber can be used, because they are relatively easy to maintain and are cost-effective. Bucket conveyors are made from a series of trays that can pick up material and carry it vertically to a higher level, and are commonly used for small parts or grains that might fall off a belt conveyor. Sticky conveyors may resemble a belt conveyor, but are made from a tacky natural or artificial rubber that allows material to lightly stick to it, which prevents material sliding back on the belt.
A screw conveyor uses a curved metal track welded to a central shaft, which results in a conveyor that resembles the threads on a bolt or screw. Material enters at one end and is transported in the spaces between each thread, until it reaches the other end and is discharged. Screw conveyors can be useful for thick solids, or mixtures of solids and liquids that would not stay in place on an open belt or bucket. They are often found on grain harvesting equipment used on farms, and transfer grain from the harvester storage tank into trucks while the harvester moves through the field.
Feed conveyors can vary greatly in length, from short conveyors feeding materials to a tank, to mining conveyors sending rock long distances to processing plants. Conveyors can send material in different directions by placing a conveyor under the end of the one before it. The product falls off the end of the first conveyor, and the second can take it is any needed direction. Trays or chutes may be added to the ends of conveyors so the product slides rather than falls, preventing product damage.