A scraper conveyor is a material transportation device utilizing a continuous, driven chain circuit equipped with regularly spaced cross members. The chain travels through an channel or trough which prevents the transported materials from falling off the conveyor while the cross members drag or “scrape” them forward to the discharge point. Scraper conveyors are typically used for coarse, heavy materials such as raw coal, iron ore, cast metal parts, and metal scrap. The design is ideal for slower transportation speeds over short distances, on moderate inclines, or even in submerged applications. This type of conveyor is typically more cost effective to install and maintain than a belt conveyor of similar capacity and length.
Most industrial processes require the constant transportation of raw materials, finished items, or byproducts from one point to the other. The conveyor, in all its many guises, is probably one of the most commonly used methods of moving materials in production and manufacturing environments. The scraper conveyor is one such conveyor and sees extensive use in these industries as an efficient, low cost method of moving coarse, non-abrasive materials. These systems are ideal for moving large, heavy items or aggregates over fairly short distances, up moderate inclines, or even under water. They are relatively cheap to install and maintain and are reliable under a wide range of conditions.
A scraper conveyor has, at its heart, a continuous flexible chain or set of chains typically driven by a sprocket equipped electric motor. A single chain arrangement runs down the center of the conveyor; dual chain setups feature chains which run on either side. This chain is fitted at regular intervals with scrapers which either protrude on either side of a single chain or are supported on either end by the dual chains. These scrapers advance with the chain scraping material on the conveyor forward towards the discharge end. The chain return route may either be over the top of the conveyor or below it depending on the specific configuration.
The chain or chains run inside a partially enclosed trough or channel which forms a contained path for the transported material and prevents spillage. These conveyors may also be used in submerged configurations as is the case in ash removal systems on coal fired generators. The scraper conveyor is an ideal, low cost alternative to other conveyor systems such as belt conveyors due to its competitive cost and ease of maintenance. Scraper conveyor systems are also less prone to damage when transporting heavy, irregularly shaped items such as foundry castings and metal scrap.