Apparatus and discontinuous method for cleaning waste water

摘要

The discontinuous method comprises supplying sewage (13) into a reactor (10), aerating the reactor contents, terminating the aeration and dropping of mud (14), and withdrawing clarified water (18) and a part of dropped mud. Mud measurement of the reactor contents is carried out within the reactor during dropping the mud and/or withdrawing the clarified water. An outflow device (19) for withdrawing clarified water is activated during reaching a given threshold value. The withdrawal speed is determined by the measured value received during the mud measurement. The discontinuous method comprises supplying sewage (13) into a reactor (10), aerating the reactor contents, terminating the aeration and dropping of mud (14), and withdrawing clarified water (18) and a part of dropped mud. Mud measurement of the reactor contents is carried out within the reactor during dropping the mud and/or withdrawing the clarified water. An outflow device (19) for withdrawing clarified water is activated during reaching a given threshold value. The withdrawal speed is determined by the measured value received during the mud measurement. The further mud measurement is carried out in the withdrawal phase. A withdrawal valve for the withdrawal of clarified water is closed during exceeding a given threshold value. The mud measurement is carried out in a periodical time interval or continuously carried out in optical way by scattered light method. The measurement of the height of the dropped mud takes place via a density determination of clarified water and mud in acoustic way by ultrasound process. The height of the dropped mud in the reactor is determined after the withdrawal of the clarified water and a reduction arrangement for the withdrawal of mud is activated during exceeding a given threshold value. The monitoring of the filling state is carried out within the reactor during dropping process and withdrawal process in optical or acoustic way by other non-clogging level detection system. An independent claim is included for a device for sewage cleaning.