Process and apparatus for aerating and mixing liquid in a tank

摘要

A process is proposed for aerating and mixing liquid in a tank (30), in particular wastewater/sludge mixture in an aerobic biological purification of wastewater in an activated tank, by means of a rotor (10) with rotor blades (14) rotating about a vertical axis (20), the liquid flowing in from the tank (30) from above into a stator (18) arranged around the rotor (10), the liquid being sucked downwards through the stator (18) by the rotor (10), air being sucked in by shear forces acting in an annular gap (46) between rotor blades (14) and the stator (18) and centrifugal forces in the gap (46), there being divided to form bubbles (52) and being introduced into the liquid and the liquid containing the air bubbles (52) flowing out from the stator (18) into the tank (30). <IMAGE>