JP2000237565A - Gas-diffusing/agitating device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To contrive atomizing diffused bubbles in that in which waste water is agitated by an agitator immersed in the waste water in a treatment tank to discharge bubbles of fed air into the waste water to diffuse them by installing a gas-diffusing unit for discharging and diffusing bubbles of fed air at a propeller blade. SOLUTION: A casing 2 of a gas-diffusing/agitating device 1 is constituted of an upper casing 2a, a lower casing 2b, and frames 2c. An agitating flow is straightened by an encircling body 4 supported between the upper and lower casings 2a, 2b supported by the plurality of frames 2c. And an agitator 5 is installed between the upper and lower casings 2a, 2b, and in the agitator 5, when a submergible motor 3 in the upper casing 2a is driven by a controller, a propeller 50 is rotated through a driving shaft 32 to make a turning flow take place in water W in the tank. And at this time, air fed from an atmosphere source through an air intake pipe 71 is fed to a gas-diffusing chamber of a gas-diffusing unit 56 at the blade end through a hollow chamber 54 and an air passing path 52 of a propeller boss 51 and is dispersed from diffusing holes on both sides in the radial and centripetal directions in bubbles.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a diffuser / stirrer, and more particularly, to a diffuser which is installed in an aerobic reaction tank for wastewater treatment and agitates wastewater by a stirrer equipped with a propeller. It relates to a gas / stirring device.

[0002]

2. Description of the Related Art A conventional apparatus of this kind is disclosed in
Japanese Patent Application Laid-Open No. 11059/1995 discloses an invention of a "water aeration apparatus". FIG. 8 shows a part of a drawing of the publication in this conventional apparatus. In FIG. 8, D is a water guide duct, E is an air supply pipe, and G is an intake pipe. 101 is a prime mover, 102 is a speed reduction mechanism, 106 is a propeller for stirring and pumping,
107 is a diffuser, 108 is a minute vent, and 113 is an impeller.

When the prime mover 101 shown in FIG. 8 is operated, the impeller 113 rotates and the air is sucked from the intake pipe G and is supplied to the diffuser rotor 107 through the air supply pipe E. At the same time, the rotation of the prime mover 101 is reduced by the reduction mechanism 102, and the stirring pumping propeller 106 and the diffusing rotor 107 are rotated at a low rotation speed. The air sent to the rotating diffusing rotor 107 is blown into the drainage purifying tank through the minute ventilation holes 108. Further, the stirring and pumping propeller 106 rotating at a reduced speed generates an upward water flow at the bottom of the drainage water purifying tank having a high water pressure, and the diffuser rotor 107 is rotated.
The water containing bubbles ejected from is raised. The water in which the air bubbles are stirred and mixed in this way is sent into the water guide duct D,
It is described that oxygen is dissolved in water by being discharged in a slightly upward direction as indicated by an arrow.

[0004]

The "underwater aeration apparatus" shown in FIG. 8 is configured such that bubbles blown out from a diffuser rotor 107 are lifted and stirred by a stirring pumping propeller 106 which rotates at a low speed by a motor 101. It has become. However, the rotation of the agitation propeller 106 is low and the relative speed difference with water is small, so that the air bubbles that have come out of the diffuser rotor 107 are likely to be substantially only raised by the pumping propeller 106. For this reason, even though small bubbles can be produced to some extent, it is not possible to sufficiently reduce the size of the bubbles, and there is a limit to the improvement of the oxygen transfer rate that governs the rate of the biological reaction.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problems of the conventional apparatus. The unit is not only suitable for assembling and maintenance / inspection, but also a diffuser that can reduce the maintenance cost.
It is intended to realize a stirring device.

[0006]

SUMMARY OF THE INVENTION The present invention relates to an aeration / stirring apparatus which stirs waste water with a stirrer immersed in the waste water in a treatment tank, discharges air bubbles of supply air into the waste water, and diffuses the air. An air diffusion / stirring device is provided in which an air diffusion unit that emits air bubbles and diffuses air is provided on a propeller blade. Further, in the above-mentioned means 1, the air diffusing unit is provided at the blade tip of the propeller blade. Also, in the above-mentioned means 1 or 2, an air diffusing / stirring device is formed in which the air diffusing holes of the air diffusing unit are formed in a unit structure. Further, in the above-mentioned means 3, a diffusing / stirring device is formed in which the diffusing holes are formed of a porous material. Furthermore, in the above-mentioned means 3, an air diffusing / stirring device is formed in which the air diffusing holes are formed by fine small holes.

[0007]

FIG. 1 is a sectional view showing the structure of a first embodiment of the present invention, and FIG.
2 is a plan view showing the configuration of the propeller according to the first embodiment, FIG. 3 is an enlarged view showing a part of the configuration of FIG. 2, FIG. 4 is an explanatory view taken in the direction of the arrow in FIG. 2, and FIG. FIG. 2B is a view taken in the direction of arrow A, and FIG.
FIG. 1 and 2, reference numeral 1 denotes a diffuser / stirring device, and 2 denotes a housing of the diffuser / stirring device 1. The housing 2 includes an upper housing 2a, a lower housing 2b, and a frame 2c, and the upper and lower housings 2a and 2b are interconnected by a frame 2c. Reference numeral 3 denotes a submersible motor, and 4 denotes an annular enclosure. Reference numeral 30 denotes an electric motor of the underwater motor 3, and 32 denotes a drive shaft. These electric motors 30 and the like are housed in a liquid-tight state inside the upper housing 2a.

The enclosure 4 is supported by a plurality of frames 2c between the upper housing 2a and the lower housing 2b, and is provided concentrically outside the rotation locus circle of the propeller of a stirrer described below to form a stirring flow. Rectifies and protects the propeller.
Reference numeral 5 denotes a stirrer provided between the upper housing 2a and the lower housing 2b. 50 is a propeller of the stirrer 5 and 51 is a drive shaft 3
2 is a propeller boss (hub) fixed to 2. The propeller 50 includes, for example, three blades 50a in the form of a six-section circular fan.
The blade roots are connected to the propeller boss 51 by 50b and 50c (hereinafter simply referred to as 50a).

Reference numeral 52 denotes an air passage provided in the radial direction of the propeller 50, 53 denotes an air diffusion hole made of a porous material, and 54 denotes a hollow chamber provided at the axis of the propeller boss 51. 56 is an aeration unit. The diffusing unit 56 is a propeller blade 5
0a is formed by a hollow arc-shaped wall provided at each wing tip,
The outer peripheral surface is formed in an arc surface having a radius equal to the rotation locus circle of the blade tip. Reference numeral 56a denotes an air diffusion chamber which is formed of an arcuate hollow portion which communicates with the air passage 52 which represents a connection portion between the propeller and the air diffusion unit. As shown in FIG. The air holes 53 are continuously open along the rotation direction of the upper and lower surfaces of the propeller blade 50a (one side surface may be used).

Reference numeral 6 denotes a bearing mechanism provided on the lower housing 2b.
Reference numeral 60 denotes a seal bearing of the bearing mechanism 6. The seal bearing 60 rotatably supports the propeller boss 51 and maintains the hollow chamber 54 inside the propeller boss 51 in an airtight state. 71 is an air supply pipe, and 81 is a tank bottom of a wastewater tank (the whole is not shown). In addition, although not shown, a control device connected to a power supply, an air supply device, and the like are provided outside the wastewater tank. The air pressure source of the air supply device supplies air for air diffusion to the air diffusion holes 53 through the air supply pipe 71, and the control device controls the output pressure of the air pressure source, the output rotation speed of the electric motor 30 of the submersible motor 3, and the like. It has become. W is water such as sewage stored in a wastewater tank, a is a bubble, and ZZ is the rotation axis of the propeller 50.

Next, the operation of the air diffusing / stirring apparatus 1 of the present invention having the above-described structure will be described. The diffuser / agitator 1 is shown in FIG.
As shown in (2), it is immersed in a wastewater tank such as a wastewater treatment facility and the lower housing 2b is fixed on the tank bottom 81 and installed. Then, when the underwater motor 3 in the upper housing 2a is driven by the control device provided outside the tank, the propeller 50 rotates at a predetermined rotation speed via the drive shaft 32, and the propeller 50 descends to the water W in the tank. A spiral swirling flow in the direction is generated.

Due to the generated swirling flow, as shown by the arrow in FIG. 1, water W in the upper layer portion of the tank is taken into the axial center Z-Z side, and is pushed down toward the lower layer portion. It flows out of the device through the arc surface. At the same time, the air supplied from the air pressure source through the air supply pipe 71 is
The air is supplied to the air diffuser 56a of the air diffuser unit 56 provided at the wing tip through the hollow chamber 54 and the air passage 52. Aeration room 5
The supply air sent to 6a is diffused in the radial direction and the centripetal direction as air bubbles a from the air diffusion holes 53 on both sides as shown in FIG. 3 (only the radial direction or the centripetal direction may be used).

In this case, since the air diffusing unit 56 is provided at each blade tip of the propeller blade 50a at which the peripheral speed becomes the maximum value, the bubble a becomes large at the moment when it is discharged from the inner and outer peripheral wall surfaces through the air diffusing hole 53. It is exposed to the water W flowing along the peripheral wall at a relative speed difference. For this reason, a shear force acts on the air discharged from the fine diffuser holes 53 of the porous material, and the air is cut off instantaneously in accordance with the increase in the number of revolutions of the propeller 50, so that finer bubbles a are formed. become. As a result, the surface area of the bubbles a released into the water is dramatically increased, and the speed at which oxygen in the bubbles a is dissolved into the water is increased accordingly, so that the air diffusion effect can be improved.

When the rotation speed of the propeller is increased, the relative speed difference between the water W and the propeller 50 is increased in accordance with the increase, so that the shear force received from the water flow is increased. The diameter can also be controlled by the rotation speed of the propeller 50 and the amount of air supplied. Although not shown, if a saw-toothed spiral piece or the like is formed on the inner peripheral surface of the enclosure 4 (FIG. 1) facing the outer surface of the air diffuser unit 56, the shearing force at this time can be further increased. Is also possible.

FIG. 5 is an explanatory view showing a configuration of an application (modification) of the first embodiment, FIG. 6 is a sectional view taken along the line AA of FIG. 5, and FIG. 7 is an enlarged view showing the configuration of the air diffusion unit of FIG. In the exploded view,
(A) and (b) are a top view and a cross-sectional view, and (c) is a cross-sectional view near a mounting portion. The air diffusing unit 56 of the application example shown in FIG. 5 is also provided at the tip of each propeller blade 50a. In particular, the diffuser holes 53 of the diffuser unit 56 of this application example have a unit structure that can be disassembled and detached as shown in FIG.

In FIGS. 6 and 7, reference numeral 53a denotes a main body of a cylindrical air diffusion hole unit, 53b denotes an air diffusion plate, and 53c denotes a seal ring. 53d is a tightening ring, 53e, 5
3f is a male and female screw to be screwed mutually, 53g is a main body 53
a and locking holes provided in the fastening ring 53d. 53
Reference numeral h denotes a mounting hole formed in the air diffusion unit 56, and a female screw 53e is screwed on the inner peripheral surface. The diffuser plate 53b is also made of a porous material, and has a convex cross section and a disc shape. The diffuser plate 53b is fitted into the main body 53a, and is tightened from the rear side by a tightening ring 53d in which a tool pin is engaged with a locking hole 53g, and is incorporated into the main body 53a.

A diffuser unit 53 incorporating a diffuser plate 53b is removably mounted in a mounting hole 53h of a diffuser unit 56 provided at the tip of each propeller blade 50a.
When the propeller 50 rotates in the direction of the arrow P, the supply air sent to the ventilation path 52 is released into the water W as air bubbles a via the air diffusion plate 53b, and effective air diffusion is performed in the same manner as described above. Is performed. According to the application examples of FIGS. 5 to 7 having the unitized diffuser holes 53, the diffuser plate 53b is detachable,
Moreover, each component of the unit is configured to be disassembled.

Therefore, when the air diffusing function is deteriorated due to clogging or damage, the air diffusing plate 53b can be removed and replaced with a new air diffusing plate 53b or a diffusing plate 53b having a different air permeability. Further, when a new material excellent in air bubbles of the supply air is developed, the new material can be immediately coped with, which is extremely advantageous in terms of maintenance. In addition, the present invention can be applied to the case where the diffuser plate 53b is not a porous material but is a diffuser plate 53b provided with a group of pores having different hole diameters.

In the above-described embodiment of the present invention, a case has been described in which the propeller is a fan-shaped propeller blade having three fan blades. However, the present invention is applied to a propeller blade whose number and shape are arbitrarily selected. Can also. Also, the case where the diffuser plates of the diffuser unit are arranged on a straight line with the same diameter is illustrated, but they are arranged in multiple rows or irregularly with different diameters, and in some cases, circular micropores and a porous material. May be combined.
In addition, the structure of the detachable air diffusion unit using the ring-shaped screw is shown, but the air diffusion unit itself including the air diffusion unit may be disassembled, and the mounting structure of the diffusion plate etc. is not necessarily implemented. The present invention is not limited to the configuration shown in the embodiment. Furthermore, the direction of the water flow in the treatment tank may be from bottom to top.

[0020]

According to the present invention, there is provided a diffuser / stirrer which stirs waste water with a stirrer immersed in waste water in a treatment tank, discharges air bubbles of the supply air into the waste water and diffuses the air. A diffuser / agitation device was provided in which a diffuser unit for releasing and diffusing air was provided on a propeller blade. In the above means 1, the air diffusion unit is provided at the tip of the propeller blade.
A stirrer was configured. Further, in the above-mentioned means 1 or 2, an air diffusing / stirring device is formed in which the air diffusing holes of the air diffusing unit are formed in a unit structure. In the above means 3,
An air diffusing / stirring device having an air diffusing hole made of a porous material was constructed. Further, in the above-mentioned means 3, an air diffusing / stirring device in which the air diffusing holes are constituted by fine small holes is constituted.

As a result, the following effects can be obtained. (1) A diffusing hole is provided in the rotating propeller of the stirrer, and the air for diffusing is directly discharged from the diffusing hole. Therefore, the diffusing cylinder and diffusing rotor of the conventional device are eliminated, and the entire structure is simplified. Can be configured. (2) By diffusing air from the tip of the propeller having a high peripheral speed, when the air bubbles are released into the water, the air bubbles are divided into fine air bubbles due to the shearing force caused by the relative flow velocity with the large water due to the rotation of the propeller. As a result, the surface area of the bubbles released into the water dramatically increases, and the speed at which oxygen in the bubbles dissolves into the water increases in proportion to the increase in the surface area of the bubbles, thereby improving the air diffusion effect. (3) Since the diffuser unit including the detachable diffuser unit is configured by disassembling the constituent members, maintenance of the diffuser plate can be performed easily and quickly, and when the pores are clogged or damaged. Can reduce the repair cost by replacing only the corresponding member. In addition, it is possible to select and use a diffuser plate having an air permeability corresponding to the properties of the wastewater to be diffused, and to configure an effective diffuser. Further, when a high-performance diffuser plate is developed with a new material, it is possible to improve the performance of an existing device at a minimum cost by replacing only the diffuser plate.

As described above, according to the present invention, there is provided an air diffusing / stirring apparatus capable of realizing an effective air diffusing in accordance with the miniaturization of the air bubbles to be diffused and improving the maintenance by adopting a unit structure of the air diffusing section. can do.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view illustrating a configuration of a first embodiment of the present invention.

FIG. 2 is a plan view showing a configuration of the propeller according to the first embodiment.

FIG. 3 is an enlarged view showing a configuration of a part of FIG. 2;

FIG. 4 is an explanatory diagram viewed from an arrow in FIG. 2;

FIG. 5 is an explanatory diagram showing a configuration of an application example of the first embodiment.

FIG. 6 is a sectional view taken along line AA of FIG. 5;

FIG. 7 is an exploded view showing the configuration of the air diffusion hole unit of FIG.

FIG. 8 is a cross-sectional view showing a configuration of a conventional device.

[Explanation of symbols]

 DESCRIPTION OF REFERENCE NUMERALS 1 diffuser / stirrer 2 housing 3 underwater motor 5 stirrer 6 bearing mechanism 32 drive shaft 50 propeller 50a, 50b,... Plate 53h Mounting hole 54 Hollow chamber 56 Air diffuser unit 56a Air diffuser chamber 60 Seal bearing 71 Air supply pipe a Air bubble P Rotation direction W Water

Claims (5)

[Claims] 1. An aeration / stirring device that stirs waste water with a stirrer immersed in waste water in a treatment tank and discharges and diffuses bubbles of supply air into the waste water. An air diffusion / stirring device, wherein an air diffusion unit for diffusing air is provided on a propeller blade. 2. The air diffusing / stirring device according to claim 1, wherein the air diffusing unit is provided at a tip of a propeller blade. 3. The air diffusing / stirring device according to claim 1, wherein the air diffusing holes of the air diffusing unit are formed in a unit structure. 4. The air diffusing / stirring device according to claim 3, wherein the air diffusing holes are made of a porous material. 5. The air diffusing / stirring device according to claim 3, wherein the air diffusing holes are formed by fine small holes.