JPH08257586A - Submersible stirring aerator - Google Patents

Abstract

PURPOSE: To provide a submersible stirring aerator in which local variance of oxygen dissolution efficiency inside an aeration tank is prevented from being caused. CONSTITUTION: A submersible stirring aerator is constituted of a submersible motor 11, a water conveying impeller 14 forming a downward current and an air diffusion cone 34 which is fitted to the lower part of the water conveying impeller 14 and consists of a tilting part and a hanging part. The submersible stirring aerator is provided with the body part 37a which surrounds the water conveying impeller 14 and forms a first current path 40, an outer sheath body 35 equipped with a tilting part 37b extended to the lower part of the body part 37a and a baseplate 66 for forming an air flow path 62 between the air diffusion cone 34 and the baseplate 44 and forming a second current path 41 between the tilting part 37b and it. An annular weir part 47 is formed in the outer part in the diametral direction of the hanging part and an annular air- blowing out nozzle 48 is formed. Since air is blown out upward and water to be treated is allowed to flow downward, the blown out air is formed into fine particles.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION The present invention relates to stirring in water.
It concerns aeration devices.

[0002]

2. Description of the Related Art Conventionally, in an underwater stirring and aeration device used in a water treatment facility, an underwater motor is arranged in an aeration tank, and a diffusing cone is attached to a water impeller rotated by the underwater motor. Air is ejected from the peripheral portion of the air diffusion cone into the water to be treated.

FIG. 2 is a schematic view of a conventional underwater stirring and aeration device. In the figure, 11 is a submersible motor immersed in water to be treated in an aeration tank (not shown), 12 is a speed reducer for decelerating rotation generated by driving the submersible motor 11, and 14 is a speed reducer. The water impeller is rotated by the submersible motor 11 to form a downward water flow.

An air diffuser cone 18 is attached to the outer periphery of the lower end of the boss 15 of the water supply impeller 14, and the air diffuser cone 18 is attached.
Rotates as the water impeller 14 rotates. The air diffuser cone 18 is composed of an inclined portion 18a that is inclined from the mounting portion of the boss 15 and extends downward, and a horizontal portion 18b that horizontally extends from the lower end of the inclined portion 18a. Then, the water supply impeller 14 and the air diffuser cone 18 are surrounded to surround the exterior body 2.
0 is allocated. The exterior body 20 is the water supply impeller 1
4, a tubular portion 20a extending around the circumference 4, an upper inclined portion 20b extending downward from the lower end of the tubular portion 20a along the inclined portion 18a above the inclined portion 18a, and an inclined portion 18a below the inclined portion 18a. The lower inclined portion 20c extends downwardly, and the horizontal portion 20d extends horizontally from the lower end of the lower inclined portion 20c.

Then, the upper inclined portion 20 of the exterior body 20.
b and the inclined portion 18a of the air diffuser cone 18 between the water flow path 25
However, an air passage 26 is formed between the inclined portion 18a of the air diffuser cone 18 and the lower inclined portion 20c of the exterior body 20, and an annular air ejection nozzle 27 is formed at the lower end of the air passage 26. . In addition, the peripheral edge of the upper inclined portion 20b and the lower inclined portion 2
An annular mixture outlet 28 is formed by the periphery of 0c. The air supply pipe 30 is opened in the air flow passage 26 so as to face the end surface of the boss 15, and the air flow passage 2 is provided.
Supply air to 6.

In the underwater stirring and aeration device having the above structure,
The rotation generated by driving the submersible motor 11 is reduced by the speed reducer 12 and transmitted to the water feed impeller 14. The air diffuser cone 18 is fixed to the boss 15 of the water supply impeller 14, and therefore rotates as the water supply impeller 14 rotates. Then, the water to be treated flows downward in the tubular portion 20a of the outer casing 20 as the water impeller 14 rotates, and flows downward in the water flow passage 25 along the inclined portion 18a of the air diffusion cone 18. . On the other hand, the air supplied by the air supply pipe 30 is supplied to the air flow path 26 from the opening, flows downward in the air flow path 26 along the inclined portion 18a of the diffusion cone 18, and flows from the air ejection nozzle 27 to the water flow. It is ejected into the path 25.

At this time, the water to be treated and the air are mixed, and the air is atomized by the centrifugal force of the diffuser cone 18 to form fine bubbles. Then, the mixture of the water to be treated and air (hereinafter referred to as “mixture”) is
It is sent from the mixture outlet 28 into the aeration tank. in this case,
The fine bubbles form a film and are dispersed in the water to be treated.

[0008]

However, in the conventional underwater stirring and aeration device, the air jet nozzle 2 is used.
When the amount of air jetted from 7 increases above the limit value and the mixing ratio of air and water to be treated reaches 5 to 6%, fine air bubbles collect at the jetting portion of the air jet nozzle 27 and become coarse. Not only does a large amount of coarse air bubbles rise up against the flow of the water to be treated as it is, but also a large amount of water to be treated flows backward in the outer casing 20 due to the rising coarse air bubbles, causing a break phenomenon. Will end up.

As a result, the water to be treated and the air are not sufficiently mixed, and the oxygen dissolution efficiency in the aeration tank is 15-.
It drops to 18% and the aeration becomes insufficient.
Further, since the mixture outlet 28 is formed on the entire circumference of the exterior body 20, a drift occurs in the mixture sent from the mixture outlet 28 into the aeration tank. Therefore, local variations occur in the oxygen dissolution efficiency in the aeration tank.

The present invention can solve the problems of the conventional underwater aeration and aeration device and increase the amount of air to be ejected, and can make the bubbles fine even if a large amount of air is ejected. An object of the present invention is to provide a submerged stirring aeration device capable of preventing local variations in the oxygen dissolution efficiency in the aeration tank.

[0011]

Therefore, in the underwater stirring aeration apparatus of the present invention, a submersible motor immersed in the water to be treated in the aeration tank and a downward water flow rotated by the submersible motor. And an aeration part that is attached to the lower part of the water supply impeller and that extends obliquely downward, and a hanging part that extends vertically downward from the lower end of the inclination part, and diffuser that rotates with the water supply impeller. A cone, a body that surrounds the water impeller and forms a first water flow path, and an exterior body that includes an inclined portion that extends downward from the lower end of the body, and is disposed inside the exterior body. And a bottom plate that forms an air flow path between the air diffusion cone and the diffusing cone, and forms a second water flow path between the air flow path and the inclined portion.

An annular weir portion is formed on the bottom plate radially outward of the hanging portion so as to project upward, and the weir portion and the hanging portion form an annular air jet nozzle. It

[0013]

According to the present invention, as described above, in the underwater aeration and aeration device, the submersible motor immersed in the water to be treated in the aeration tank and the submersible motor are rotated to form a downward water flow. A water-conveying impeller, an inclined portion that is attached to the lower side of the water-feeding impeller and that extends obliquely downward, and a hanging portion that vertically extends downward from the lower end of the inclined portion, and an aeration cone that rotates with the water-feeding impeller. An outer body that includes a body portion that surrounds the water supply impeller to form a first water flow path, and an inclined portion that extends downward from the lower end of the body portion, and is disposed inside the outer body. An air flow path between the air diffusion cone and a second air flow path between the inclined portion and
And a bottom plate forming a water flow path.

An annular weir portion is formed on the bottom plate radially outward of the hanging portion so as to project upward, and the weir portion and the hanging portion form an annular air ejection nozzle. In this case, the rotation generated by driving the submersible motor is transmitted to the water feed impeller and rotates the water feed impeller.

Since the air diffuser cone is fixed to the water supply impeller, it is rotated as the water supply impeller rotates. Then, the water to be treated flows downward in the first water flow path as the water supply impeller rotates. On the other hand, the air supplied to the air flow path is ejected from the air ejection nozzle and mixed with the water to be treated flowing in the first water flow path to form a mixture. Then, the mixture is sent from the second water channel into the aeration tank.

[0016]

Embodiments of the present invention will now be described in detail with reference to the drawings. 1 is a schematic view of an underwater stirring aeration device according to a first embodiment of the present invention, and FIG. 3 is a cross-sectional view of a main part of the underwater aeration aeration device according to the first embodiment of the present invention.
FIG. 4 is a sectional view of the second water channel in the first embodiment of the present invention.

In FIG. 1, 11 is an underwater motor immersed in the water to be treated in an aeration tank (not shown), 12 is a speed reducer for decelerating the rotation generated by driving the underwater motor 11, and 14 is The water impeller is rotated by the submersible motor 11 to form a downward water flow. A frustoconical diffusing cone 34 is attached to the outer periphery of the lower end of the boss 15 of the water feeding impeller 14, and the diffusing cone 34 is rotated as the water feeding impeller 14 rotates. And the aeration cone 34 is the boss 1.
5, an inclined portion 34a that is inclined from the attachment portion and extends downward, and a hanging portion 34b that vertically extends downward from the lower end of the inclined portion 34a.

An outer casing 35 is provided below the inside of the aeration tank so as to surround the water supply impeller 14 and the air diffuser cone 34.
Is arranged. The exterior body 35 is composed of an upper exterior body 36 forming a suction part for the water to be treated and a lower exterior body 37 for feeding the water to be treated. Inside the upper exterior body 36, an annular suction port 36a for sucking the water to be treated is formed.
The lower exterior body 37 includes a body portion 37a extending downward from the periphery of the water supply impeller 14 to a position substantially the same as a lower end of the inclined portion 34a, and an inclined portion extending downward from the lower end of the body portion 37a. It consists of 37b.

The body portion 37a of the lower exterior body 37
An annular first water flow channel 40 is formed inside the first water flow channel 40, and the first water flow channel 40 is connected to the suction port 36a. further,
A second water channel 41 is formed inside the inclined portion 37b of the lower exterior body 37, and the second water channel 41 is connected to the first water channel 40. The second water channels 41 are radially formed at a plurality of positions in the circumferential direction of the inclined portion 37b. Therefore, the water to be treated flowing in the first water flow passages 40 is evenly divided and flows radially outward in the respective second water flow passages 41. The second water channel 41 is formed by fixing a bottom plate 44 inside the inclined portion 37b, and radial grooves 45 as shown in FIG. 4 are formed at a plurality of positions in the circumferential direction of the bottom plate 44. Second water channel 41
Is formed.

An air jet P1 is formed between the first water flow passage 40 and the second water flow passage 41, and air is jetted to the air jet P1. Therefore, an air flow path 42 is formed between the air diffuser cone 34 and the bottom plate 44. An annular weir portion 47 is formed on the bottom plate 44 radially outward of the hanging portion 34b so as to project upward. Therefore, the weir portion 47 and the hanging portion 34b in the air flow path 42 form an annular air ejection nozzle 48.

In this case, the water to be treated in the aeration tank is sucked through the suction port 36a and flows downward in the first water flow path 40 toward the air ejection portion P1, whereas The air supplied to the air passage 42 is the air jet nozzle 4
8 is ejected upward toward the air ejection portion P1.
Then, the mixture is sent into the aeration tank from the mixture discharge port 55 formed at the tip of the second water flow path 41. An air introducing pipe 50 is connected to the center of the bottom plate 44, and an air introducing port 51 is formed so as to face the air flow path 42. The air introduction pipe 50 is connected to a compressed air supply source (not shown), and the air supplied from the compressed air supply source is supplied to the air flow path 42 via the air introduction pipe 50.

In the underwater stirring and aeration device having the above structure,
The rotation generated by driving the submersible motor 11 is reduced by the speed reducer 12 and transmitted to the water feed impeller 14 to rotate the water feed impeller 14. Since the air diffusion cone 34 is fixed to the boss 15 of the water supply impeller 14, it is rotated along with the rotation of the water supply impeller 14. The water to be treated is the water impeller 1
With the rotation of 4, the air is sucked from the suction port 36a of the upper exterior body 36 and flows downward in the first water channel 40.

On the other hand, the air supplied to the air flow passage 42 through the air introduction pipe 50 is ejected from the air ejection nozzle 48 toward the air ejection portion P1 and flows in the first water flow passage 40. It is mixed with water to be treated to form a mixture. Then, the mixture reaches the mixture discharge port 55 through the second water flow path 41, and is sent from the mixture discharge port 55 into the aeration tank. The mixture sent into the aeration tank gradually forms an upward water flow as the bubbles rise, and flows upward.

By the way, in the air ejection portion P1,
The air is jetted upward, whereas the water to be treated is made to flow downward at an angle set in the range of 90 to 180 [°]. Therefore, the ejected air forms fine particles, so that the oxygen dissolution efficiency in the aeration tank is increased and the aeration can be sufficiently performed.

Further, since the mixture discharge port 55 is formed so as to correspond to the groove 45, the mixture formed in the air ejection portion P1 is evenly sent to each second water flow passage 41. Therefore, a mixed flow is not generated in the mixture sent from the mixture discharge port 55 into the aeration tank, and it is possible to prevent a local variation in the oxygen dissolution efficiency in the aeration tank. The length of the mixture discharge port 55 in the circumferential direction is 20 to 8 of the entire circumference of the inclined portion 37b.
It is set to 0%.

Further, the water to be treated flowing in the first water flow passage 40 becomes a mixture in the air jet portion P1 and is sent to the second water flow passage 41, but at this time, the flow passage cross-sectional area becomes small. . Therefore, the flow of the mixture becomes faster than the flow of the water to be treated, and the mixture reaches a position away from the mixture discharge port 55, so that the entire inside of the aeration tank can be aerated uniformly.

Next, a second embodiment of the present invention will be described. FIG. 5 is a schematic view of an underwater stirring and aeration device according to the second embodiment of the present invention, and FIG. 6 is a sectional view of a second water flow path according to the second embodiment of the present invention. In this embodiment,
An exterior body 35 is arranged below the aeration tank (not shown) so as to surround the water supply impeller 14 and the air diffusion cone 34. The exterior body 35 is composed of an upper exterior body 36 forming a suction part for the water to be treated and a lower exterior body 137 for feeding the water to be treated. The lower exterior body 137 includes a body portion 137a extending downward from the periphery of the water supply impeller 14, and the body portion 137a.
Is formed of an inclined portion 137b extending downward from the lower end of the inclined portion 137b.

Then, the body portion 13 of the lower exterior body 137.
An annular first water channel 40 is formed inside 7a, and a second water channel 41 is formed inside the inclined portion 137b. The second water channels 41 are radially formed at a plurality of positions in the circumferential direction of the inclined portion 137b. Also, the second
The water flow path 41 is formed by fixing the bottom plate 144 to the inside of the inclined portion 137b, and radial grooves 145 are provided at a plurality of positions in the circumferential direction of the inclined portion 137b as shown in FIG. The number of paths 41 is formed. In addition, 51 is an air inlet.

The present invention is not limited to the above-mentioned embodiments, but can be variously modified within the scope of the present invention, and these are not excluded from the scope of the present invention.

[0030]

As described in detail above, according to the present invention, in the underwater stirring aeration device, the submersible motor immersed in the water to be treated in the aeration tank and the submersible motor rotated by the submersible motor. A water impeller that forms a downward water flow, an inclined portion that is attached below the water impeller and that extends obliquely downward, and a hanging portion that vertically extends downward from the lower end of the inclined portion, together with the water impeller. An exterior body having a rotating air diffuser cone, a body portion surrounding the water supply impeller to form a first water flow path, and an inclined portion extending downward from the lower end of the body portion, and the exterior body. And a bottom plate that is disposed inside the air diffuser cone and that forms an air flow path between the air diffuser cone and the second water flow path between the air flow path and the inclined portion.

Further, an annular weir portion is formed so as to project upward on the radially outer side of the hanging portion of the bottom plate, and an annular air jet nozzle is formed by the weir portion and the hanging portion. In this case, the air is jetted upward, while the water to be treated is flown downward.
Therefore, the ejected air forms fine particles, so that the oxygen dissolution efficiency in the aeration tank is increased and the aeration can be sufficiently performed.

The mixture is evenly fed into each second water channel. Therefore, a non-uniform flow does not occur in the mixture sent into the aeration tank, and it is possible to prevent a local variation in the oxygen dissolution efficiency in the aeration tank.

[Brief description of drawings]

FIG. 1 is a schematic view of an underwater stirring and aeration device according to a first embodiment of the present invention.

FIG. 2 is a schematic view of a conventional underwater stirring and aeration device.

FIG. 3 is a cross-sectional view of an essential part of the underwater stirring and aeration device according to the first embodiment of the present invention.

FIG. 4 is a cross-sectional view of a second water channel in the first embodiment of the present invention.

FIG. 5 is a schematic view of an underwater stirring and aeration device according to a second embodiment of the present invention.

FIG. 6 is a cross-sectional view of a second water channel according to the second embodiment of the present invention.

[Explanation of Codes] 11 Submersible Motor 14 Water Impeller 34 Diffuser Cone 34a Inclined Part 34b Hanging Part 35 Exterior Body 37, 137 Lower Exterior Body 37a, 137a Body 37b, 137b Inclined Section 40 First Water Flow Path 41 Second Water flow passage 42 Air flow passage 44, 144 Bottom plate 47 Weir portion 48 Air jet nozzle

Claims (1)

[Claims] 1. An (a) submersible motor immersed in water to be treated in an aeration tank; (b) a water impeller which is rotated by the submersible motor to form a downward water flow; and (c).
A diffusing cone that is attached to the lower part of the water supply impeller and that is inclined and extends downward, and a hanging part that extends vertically downward from the lower end of the inclined part and that rotates with the water supply impeller; First to surround the water impeller
Of an outer body having a body forming the water flow path and an inclined portion extending downwardly from the lower end of the body, and (e) the diffusing cone disposed inside the outer body. An air flow path therebetween, and a bottom plate forming a second water flow path between the air flow path and the inclined portion, and (f) projecting upward in a radially outward direction of the hanging portion of the bottom plate. An underwater stirring and aeration device, wherein an annular weir portion is formed, and an annular air ejection nozzle is formed by the weir portion and the hanging portion.