Underwater aeration device

Abstract

To provide an underwater aeration device enabling prevention of closure with foreign matter, performing enhanced aeration, started under a lightened load, operated with a lessened maintenance work at a lower running cost, and manufactured at a lower cost. [MEANS FOR SOLVING PROBLEMS] An impeller (4) having a partition for sectioning a liquid passage (4w) and an air passage (4a) formed on a blade (4c) is interposed rotatably between the lower surface (5d) of an intermediate plate in which an air inlet (5s) is made and the upper surface (7u) of a suction cover in which a liquid inlet (7s) is made and contained in a guide casing (6). The liquid passage (4w) and the air passage (4a) at the distal end of the outer circumference of the partition on the back (4r) side of the blade are made to communicate with each other (4h). An intermediate impeller (4m) is provided on the outer circumference of the liquid passage (4w). The clearance between the lower end face (4d) of the blade and the upper surface (7u) of the suction cover is formed into a cone shape which is wide at the liquid inlet (7s) and narrow at the outer circumference including the guide vane tongue portion. A plurality of stand legs (8) and strainer projections (9) are projected integrally from the lower end face on the outer circumference of the lower wall (6d) of the guide casing. The upper surface (6o) of the upper wall between the air and liquid ejection passages is recessed as a down slope inclination surface widened toward the outer circumference.

Description

technical field [0001] The present invention relates to an underwater aeration device (hereinafter referred to as "submersible aeration device"), which is placed in an aeration tank for treating industrial wastewater or urban sewer wastewater. Background technique [0002] It is known to have a submerged aeration device in which, by means of the negative pressure self-suction effect of rotating the impeller in the liquid storage tank, the impeller sucks air from the atmosphere through the air duct, and sucks the waste water flowing into the storage tank (hereinafter referred to as "liquid to be treated"), mixes it with the sucked air and ejects the air-liquid mixture in the tank, thereby causing aeration. The impeller has a special structure; that is, it includes an air suction channel for sucking air and a liquid suction channel for sucking liquid to be treated. Since it is desirable to remove large solid materials that have entered the waste water by means of a screen dev...

AI Technical Summary

Problems solved by technology

Since it is desirable to remove large solid materials that have entered the waste water by means of a screen device arranged upstream of the liquid storage tank, conventional submerged aerators are not provided with the ability to remove inclusions that cannot thus be removed by means of a screen device. Objects (hereinafter referred to as "foreign objects") function of the filter or similar components

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