A bucket elevator or grain leg is a piece of equipment which is used to move materials in bulk. Bucket elevators are used in a wide variety of settings, including commercial agriculture and mining, and several specialty companies produce bucket elevators and accessories. These devices are used primarily when materials need to be handled in a large scale, and they are capable of moving huge volumes of bulk material every hour.
Essentially, a bucket elevator is like a conveyor belt with buckets attached. It can be used to move things vertically, but it can also be used for transport at an angle, or for horizontal transport, depending on the design. The buckets are designed to swivel so that they always stay upright, avoiding spillage, and their edges are scooped, so that they can pick up materials by being dragged through them. A bucket elevator can move materials like ore, fertilizer, and grain.
In a basic vertical bucket elevator, the elevator moves bulk materials up, dumps bulk materials at the top, and the empty buckets return to pick up a new load. The unloaded materials are routed into a chute which can be attached to storage containers, bags for packaging, and so forth. The bucket elevator makes materials processing purely mechanical, with no need for people to be involved beyond monitoring the activity of the elevator and changing settings as required.
More sophisticated bucket elevators can be programmed to unload materials at multiple intervals, in addition to running along horizontal tracks. As a general rule, the works of the elevator are shielded for safety, so that people are not caught in the moving elevator. This is especially important when the buckets are on a chain instead of a belt, as the chain can trap loose clothing, hair, or limbs and cause serious damage to operators and bystanders.
Like many pieces of heavy equipment, the bucket elevator is designed for continuous operation. Start and stop operation can damage the device or decrease efficiency, in addition to increasing the risk of spills. A company may opt to run a bucket elevator for a set period of hours every day, or to run the device nearly continuously if its processing needs are ample enough. The bucket elevator does have emergency stop settings which allow people to turn the device off if there is a problem, and some are sensitive to blockages which suggest that something is caught in the device, and will turn off automatically.