SUBMERGED MECHANICAL AERATOR WITH DOUBLE IMPELLERS

摘要

PURPOSE: A submerged mechanical aerator with double impellers is provided to increase interfacial area between wastewater and air introduced in aeration tank, thus improving oxygen transfer rate. CONSTITUTION: The submerged mechanical aerator with double impellers comprises the parts of a submerged motor(11) being installed airtightly; a main casing(17) being supported by a support(18) wherein a rotating shaft(11a) is supported rotatively in upper part, one end of an air suction pipe(20) is inserted into the main casing, an inlet(17wi) and an outlet(17o) of wastewater are formed at lower part and along circumferential brim of the main casing respectively; an air impeller(14a) being installed at lower part of the rotating shaft to provide fine air bubbles in wastewater(W) retained inside the main casing by introducing outer air through the air suction pipe; a wastewater impeller(14w) being installed at lower part of the air impeller to introduce wastewater retained in an aeration tank inside the main casing through a wastewater inlet(17wi). Further, from curved inner wall of an upper casing(17'') where air bubbles concentrate to inner wall of the wastewater outlet formed on the main casing, a protrusion part(17c) having many protrusions with a specific height is formed to make the air bubbles finer, thereby increasing oxygen transfer rate.