Bottom Sludge Scraper
The Zickert Z2000 bottom sludge scraper
The Zickert Z2000 bottom sludge scraper is used all over the world. It is designed for continuous sludge transport and per-forms well in allsedimentation processes, including grit cham-bers. The scraper can be powered by hydraulics or electric motors. A lever system and a number of wedge-shaped sections are welded together to form a single unit so that they function as a moving floor in the tank. Hydrodynamically designed sections The Z2000 is based on the forward and return movement of the hydrodynamically designed sections. The concave faces of the sections transport the sediment towards the sludge pit. During the return movement, the wedge-shaped parts of the sections slide under the sludge blanket. The speed of the return move-ment is roughly twice that of the forward movement. This gives continuous transport of the sludge.The shape of the sections is a result o extensive scientific tests. Experiments in testing tanks have shown that the concave shape offers the optimum solution with different types of sludge and at different scraping speeds, as well as produces the best thicken-ing results The sediment layer is scraped off from the underside The concave faces of the wedges scrape the sediment blanket from the underside. During the return movement, which is twice as fast as the forward movement, the wedges slide under the blanket. This means that the sedimentation process is uninter-rupted Where the solids content of the sludge is so low that no blan-ket is formed, the action of the scraper creates a constant flow of sludge towards the sludge pit, thickening the sludge while scraping it. The stroke of the scraper is always longer than the distance between the sections.
Easy to adapt for use in existing tanks The scraper gives the same results whether it is pulled or pushed. This offers flexibility when it comes to locating the drive. With a hydraulic drive, the cylinder can even be located in the water, in which case the number of moving joints is re-duced from four to one.
A further point is that, for the Z2000, there is no need for the bottom of the tank to be completely level. The scraper works even if the bottom slopes to one side or has long dips. The Z2000 can even cope with variations in the width of the tank. However, the tank should be horizontal or slope towards the sludge pit.
The scraper runs on slides
The wedge sections rest on three or five steel bars, depending on the width of the tank. They move on longitudinal slides of high-density polyethylene (HDPE). Wear is thus reduced to a minimum, and slides usually last for five to ten years. The slides are easily secured to the concrete bottom with hammerfixings. Where the tank is made of steel, fastening brackets welded to the bottom of the tank are used. The slides are easy to replace. Easy to install and maintain The Z2000 is easy to install. Only two people are needed to do the job. An ordinary scraper normally takes about one week to install. Components for our standard scraper are always in stock. The scraper needs very little maintenance. Stresses and strains are low because thereare few moving parts and the forces in-volved are small. The wedge sections run on polyethylene (HDPE) slides for low friction. The power demand is therefore small, resulting in mild operating conditions and long life. All material under water is non-rusting.