Process and apparatus for clearing and removing by suction settled sludge in settling tanks of sewage treatment plants

摘要

Process and apparatus for clearing and removing by suction settled sludge in settling tanks of sewage treatment plants by means of rake blades transported by carriages and suction lines, the suction throughput of which suction lines being controlled in dependence on the amount, density or another parameter of the resulting sludge. By means of the process, the size of the active clearing surface of the rake blades is controlled approximately in proportion to the suction throughput and in a further process for round tanks, the range of the enlargement of the active clearing surface is moved outward with increasing suction throughput. An apparatus for carrying out the process is formed according to the invention by at least two rake blades, one of which is always in the clearing position and the other or others are in the clearing position only when required.