CS231930B1 - Axial surface aerator - Google Patents

Abstract

The invention relates to an axial surface aerator intended in particular for aerating wastewater in activation tanks during biological treatment. The axial rotor of the aerator is located below the liquid surface. A suction pipe is located under the axial rotor of the aerator, preferably a telescopic one, which has a larger diameter than the axial rotor of the aerator. Plate vertical stops are fixed on the upper edge of the suction pipe.

Description

BACKGROUND OF THE INVENTION The present invention relates to an axial surface erector intended particularly for aeration of wastewater in activation tanks during biological treatment.

The aerator axial rotor is located below the liquid level. A suction pipe, preferably telescopic, has a diameter below the aerator axial rotor and has a larger diameter than the aerator axial rotor. On the upper edge of the suction pipe are mounted plate vertical stops.

Fig.1

BACKGROUND OF THE INVENTION The present invention relates to an axial surface aerator, particularly for aeration of wastewater in activation tanks during biological treatment.

A vertical rotary mixer for mixing liquid and gas at the interfacial interface is used to aerate the wastewater for biological purification.

The best-known are radial flow turbine aerators, which show a predominantly dispersing effect, but their pumping effect is relatively low. For a satisfactory function, they need shallow tanks with a relatively large surface area, which are expensive to invest.

Lower mixing intensity results in sludge settling, especially in relatively deep tanks, which over time will start to iron and spoil the cleaning effect.

Further, axial propeller aerators are known with a propeller-shaped rotor or with a rotor having straight sloping blades, which exhibit greater mixing intensity but have less dispersing effect, which means less oxygen transfer to the aerated liquid. Both types of aerators may be provided with suction tubes to improve circulation.

The disadvantages of the known solutions are overcome by the axial surface aerator according to the invention, which is based on placing the axial rotor of the aerator below the liquid level above the upper edge of the seed pipe having a larger diameter than the aerator axial rotor.

Preferably, the aerator axial rotor may be provided with at least three blades continuously or angled. The continuously shaped vanes have a rectangular trapezoid shape in the developed form and are shaped as a cylindrical surface whose axis is parallel and shorter diagonal.

The domain-shaped vanes are formed from two inclined angles, the intersection of which has an acute angle with the longer side of the vane, the surface at the periphery of the vane being less acute than the rotor hub surface.

The aerator axial rotor, in conjunction with the vertical plate stops at the upper edge of the suction pipe, gives a greater pumping effect with good dispersing effect, thus providing higher aeration efficiency with intensive circulation, which prevents settling 1 in deeper tanks.

By changing the direction of rotation, the device according to the invention makes it possible to reverse the flow direction of the liquid for a short time, thus ensuring rapid slurry mixing, for example after an operating outage when a larger sludge layer settles.

The accompanying drawings show an exemplary embodiment of an aeration device according to the invention.

Fig. 1 shows a plan view of the aeration tank with a Bxial surface aerator. Fig. 3 is a front elevation of a continuously shaped blade; Fig. 4 is a plan view of a continuously shaped blade; Fig. 5 is a front elevation of a pointed shaped blade;

At the center of the aeration tank 1, the drive 2 of the aerator axial rotor 6 is provided on the bridge g, provided with continuously shaped blades g or broken blades g.

The aerator axial rotor 6 is located below the liquid level g. Underneath the aerator axial rotor 6 is a suction tube g, preferably telescopic, which has a larger diameter than the aerator axial rotor. On the upper edge of the suction pipe g are mounted plate vertical stops g.

As the aerator axial rotor 6 is rotated just below the liquid level, the liquid is pumped towards the liquid level. The emerging liquid stream exceeds the liquid level and is sprayed, creating conditions for intense oxygen transfer to the liquid. The plate vertical baffles 6 increase the proportion of shear forces in the liquid, improve oxygen transfer and prevent the formation of a central vortex. Advantageously, the plate vertical stoppers 6 may be pivotally mounted so that their effect can be altered by pivoting.

The suction pipe 6 may be made in one piece or preferably made of telescopic parts allowing height adjustment according to the level.

The continuously shaped blades 8 have a rectangular trapezoid shape in the developed shape and are shaped as a cylindrical surface whose axis is parallel to the diagonal. The continuously shaped blades 8 are the subject of AO 182 028 and give maximum pumping capacity with less dispersing effect.

The refracted vanes are formed from two oblique angled surfaces whose intersection forms an acute angle with the longer side of the vanes, the surface 9a at the periphery of the vane being less acute than the rotor hub surface 9b. The ratio of the dispersing and pumping effects can be varied by the relative ratio of the angles of the two blade surfaces.

The axial surface aerator according to the invention is suitable for the aeration of waste water, in particular for deeper tanks and for the adaptation of tanks intended for oxidation comb drums, where its greater pumping effect is particularly favorable.

For smaller types, a simple and reliable belt drive can be used to advantage

Claims (3)

transfer. SUBJECT OF THE INVENTION 1. Axial surface aerator, consisting of a suction pipe, vertically placed in the aeration tank, and an axial rotor of the aerator with a drive, characterized in that the axial rotor (4) of the aerator is placed below the liquid level (5) above the upper edge of the suction pipe (6), which has a larger diameter than the axial rotor (4) of the aerator, and on the upper edge of which at least four plate vertical stops (7) are placed at the level of the axial rotor (4) of the aerator. 2. Axial surface aerator according to item 1, characterized in that the axial rotor (4) of the aerator is provided with at least three continuously shaped blades (8), which in their unfolded form have the shape of a rectangular trapezoid and are shaped as a cylindrical surface, the axis of which is parallel to the shorter diagonal of the rectangular trapezoid. 3. Axial surface aerator according to item 1, characterized in that the axial rotor (4) of the aerator is provided with at least three angle-shaped blades (X9), formed from two inclined surfaces (9a, 9b), forming an obtuse angle with each other, the intersection of which forms an acute angle with the longer side of the blade, while the surface (9a) on the periphery of the blade forms a smaller acute angle with the plane of rotation of the mixer than the surface (9b) at the hub of the axial rotor (4) of the aerator. 1 drawing II M Ί •7 8 _; 9.5 fig· 3 'o' fig.4 ////////77777, fig.1