Chain Scrapers are used in rectangular settling ponds. The scraping pallets are positioned between two separate chains mounted between the shaft and gears placed on both sides of the pool. Thus, with the rotation of the shaft driven by the drive group, the chain starts its endless rotation and directs the sludge accumulated on the floor to the collection pit. At the same time, during the rotation of the chains, the pallets scrape the oil and foam from the pool surface and direct them to the oil-foam collection compartments. There are also chain scrapers that clean the pool floor or surface with two independent scrapers, depending on the operational needs.