Abstract: The invention relates to the aerating of domestic and industrial wastewaters by means of an aerator placed on the bottom of the oxidation pond. Particularly the invention relates to the structure of the stator of the aerator. The stator comprises the stator shell structure (4), the stator ducts (7) directed outwards with respect to the outer edge of the shell structure, legs (5) attached to the shell and extending to the bottom of the pond, as well as triangular blade members (6) fastened to the said legs.

Abstract: The object of the present invention is to protect the driver unit (1) of an immersible aerator and/or mixer apparatus against the surrounding liquid. The driver unit (1) is covered with a compact protective casing (5), to the bottom part whereof the gas to be lead into the mixer (14) is conducted through the gas supply pipe (2). At the junction of the gas supply pipe (2), inside the protective casing (5), there is located a gas supply channel (6) which is open at both ends, and this gas supply channel (6) conducts the gas to flow mainly upwards, to the top part of the driver unit. At its bottom, the protective casing (5) is attached to the base disc (7), and the gas flows through the holes (10) provided in the base disc (7) into the channel formed by the gas control cone (11) and the inner cone (12), and therefrom into the liquid either via the partly hollow secondary axis (13) of the mixer or via a separate gas pipe.

Abstract: The invention relates to an immersible aerator and/or mixer apparatus to be lowered onto the bottom of a basin or tank containing liquid, often also solid substances, and particularly the invention relates to the supporting structures of the said apparatus as well as to the devices for protecting the motor and power transmission chambers of the said aerator and/or mixer apparatus from the liquid contained in the said vessel.