JP3455467B2 - Aeration device - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an aeration device, and more particularly to an aeration device used in liquid treatment equipment such as water treatment equipment.

[0002]

2. Description of the Related Art A conventional aeration apparatus is, for example, immersed in a treatment tank containing aerobic microorganisms disposed in a water treatment facility or the like, and water to be treated is fed by a water feeding impeller, and the outlet of this impeller is used. There are many known devices in which air is ejected to the side (for example, JP-A-61-36476, JP-A-62-106896, JP-A-63-63).
221896, etc.). As one of the aeration devices of this type, as shown in FIG.
As shown in (1), there is disclosed an aeration device in which a rotatable rotary cone is arranged on the outlet side of an impeller and air is ejected from the peripheral portion of the rotating rotary cone.

In this conventional aeration device 11, the speed reducer 1 is provided in a casing 12 in which a flow path for water to be treated is formed.
An impeller 17 for downward water supply, which is driven by a submersible motor 13 through 4, is provided.
A rotary cone 16 is provided on the downstream side of the. An air ejection gap is formed between the rotary cone 16 and the bottom of the casing 12. Further, a pipe end of an air supply pipe 19 for supplying air is opened below the rotary cone 16, and a space surrounded by the rotary cone 16 and the bottom wall of the casing 12 is an air supply space. It is a room 18.

[0004] The conventional aeration device 11 thus configured
Then, the rotation of the submersible motor 13 is reduced to a predetermined speed by the speed reducer 14 and transmitted to the output shaft 15, and the impeller 17 and the rotary cone 16 are rotated. The water to be treated is fed downward in the casing 12 by the impeller 17 and is discharged from the discharge port at the bottom of the casing 12. At this time, air is blown into the air chamber 18 from the air supply pipe 19,
When the air is ejected from the air ejection gap into the flow path, it is rolled into a thin film by the centrifugal force of the rotating cone 16 rotating at a high speed, and is sheared by the peripheral end of the rotating cone 16. Further, the air jetted into the flow path is crushed by the water flow from above to form fine bubbles, transferred to the discharge port of the casing 12 and discharged into the processing tank.

[0005]

By the way, in the above conventional aeration apparatus 11, when a flat rotary cone 16 as shown in FIG. 5 is used, the wall surface of the rotary cone 16 becomes a resistance of the water flow, and Since the pressure loss increased, it was not possible to sufficiently prevent the reduction of the circulation flow rate of the water to be treated. When the circulation flow rate decreases, there is a problem that the flow velocity in the flow path becomes slow and the crushing effect of the air ejected from the air ejection gap is weakened. Then, in order to compensate for the decrease in the circulation flow rate and the flow velocity in the flow path, the rotation speed of the impeller 17 must be increased, and the power consumption such as electric power is increased, which is uneconomical.

In view of the above problems, the present invention provides an aerator capable of increasing the circulating flow rate of water to be treated, improving the performance of atomizing air, and reducing the power consumption. With the goal.

[0007]

In order to solve the above-mentioned problems, the aeration apparatus of the present invention is arranged in a casing having a flow passage formed therein, and is provided on the downstream side of an impeller driven by a motor. A rotary cone is disposed coaxially and integrally with the impeller, and an air ejection gap is provided between the peripheral edge of the rotary cone and the inner wall of the casing. The angle to make is θ
Then, 60 ° <θ ≦ 85 ° .

According to the aeration device configured as described above,
The pressure of the water flow received by the wall surface of the rotating cone is smaller than before, and the flow path does not bend greatly around the wall surface of the rotating cone as before, so the pressure loss in the flow path is reduced. . Further, since the pressing force from the inner surface of the wall surface of the rotary cone acting on the air supplied below the rotary cone is increased, it is rolled into a thinner film when ejected from the air ejection gap. Furthermore, since the rotating cone is lighter than the conventional one and the rotating moment and the axial load supported by the output shaft can be reduced, the required power (work amount) of the impeller can be increased, the rotating power is reduced and the circulation flow rate can be reduced. Can be increased. Further, since the rotating cone can be made smaller than the conventional one, the outer diameter of the casing body can be made small in order to secure the flow passage having the same cross-sectional area as the conventional one.

Further, the discharge port of the casing is opened outward in a substantially horizontal direction, the vertical length of the opening of the discharge port is W [mm], the horizontal line passing through the vertical center of the discharge port, and the rotary cone. When the vertical distance from the horizontal line passing through the lower end position of the peripheral edge of the opening is Dv [mm], | Dv | ≦ W × 0.
It is preferable that the relationship of 5 is established.

With this configuration, the discharge port of the casing is located on a substantially horizontal extension line of the air ejection gap.
The thin film of air ejected from the air ejection gap always intersects with the water flow and is reliably broken by the water flow.
Further, since the jetted air always intersects with the water flow, the air goes backward to the water flow and is unlikely to float on the upstream side of the flow path, and the pressure loss in the flow path due to the air flow is reduced. Furthermore, since the air is unlikely to float to the upstream side, the air ejected from the air ejection gap is unlikely to dissipate outside the discharge port.

Furthermore, the inner diameter of the casing body portion opposite to the peripheral end of the impeller is R [mm], the vertical perpendicular line of the inner wall surface of the casing body portion, and the vertical perpendicular line passing through the peripheral edge position of the lower end of the opening of the rotating cone. It is desirable that the relationship of | Dh | ≦ R × 0.1 holds when the horizontal distance of Dh [mm].

With this configuration, the vertical position of the vertical vertical line on the wall surface of the body of the casing and the air ejection gap are substantially the same, so that the air ejection gap is located closer to the center of the casing. The jetted air goes against the water flow and becomes more difficult to float upstream of the flow path, and the pressure loss in the flow path due to the air flow becomes negligibly small. Further, as compared with the case where the air ejection gap is located closer to the outer periphery of the casing, the ejected air thin film is more likely to intersect with the water flow, and thus is easily broken by the water flow. Furthermore, since it is more difficult for the air to float to the upstream side, it is more difficult for the air ejected from the air ejection gap to dissipate outside the discharge port.

Here, as a specific structure of the aeration device, a structure in which a guide plate protruding toward the flow path is provided on the periphery of the opening of the rotary cone is adopted.

According to this structure, the air supplied from below the rotary cone is introduced into the air ejection gap along the guide plate and is ejected into the flow path while being sheared into a thin film. As compared with a rotating cone having the same minimum and maximum diameters and no guide plate, the angle θ can be increased to increase the width of the flow passage around the wall surface of the rotating cone. Can be even further reduced. In addition, since the pressing force from the inner surface of the wall surface of the rotating cone acting on the air can be further increased by increasing the angle θ, the air is further rolled and thinner when ejected from the air ejection gap. It can be in the form of a film. In addition, the aeration device of the present invention is
It is installed in the casing where the flow path is formed and
On the downstream side of the driven impeller,
A rotary cone is arranged coaxially and integrally with the rotary cone.
Air ejection gap between the peripheral edge of the container and the inner wall of the casing
The aerator is equipped with a
When the angle to the plane is θ, 60 ° <θ ≦
It is at 85 °, below the rotating cone where air is supplied.
Top surface of the bottom wall of the casing that defines the inner space
Are almost the same in the vertical direction as the peripheral portion of the rotating cone.
It is located at the bell. Further, the aeration apparatus of the present invention
The device is installed in a casing with a flow passage formed inside.
And on the downstream side of the impeller driven by the motor,
A rotating cone is installed coaxially and integrally with the impeller.
Between the peripheral edge of the rotating cone and the inner wall of the casing.
An aerating device having an air ejection gap in the
When the angle formed by the wall surface of the cone with respect to the horizontal plane is θ
And 60 ° <θ ≤ 85 °, which is the wall of the rotating cone.
The body of the casing facing the surface and the wall surface of the rotating cone
It is characterized in that they are formed substantially in parallel. Also books
In the aeration device of the invention, the wall surface of the rotating cone is a tapered surface.
It may be characterized by that.

[0015]

DETAILED DESCRIPTION OF THE INVENTION Embodiments of the present invention will be described below with reference to the accompanying drawings. FIG. 1 is a schematic vertical sectional view showing an embodiment of an aeration apparatus of the present invention. As shown in FIG. 1, the casing 2 of the aeration device 1 has a water inlet 21 of the water to be treated, which is opened upward (upward in the drawing; hereinafter, the upper and lower sides are based on the drawing), and is substantially horizontal. Has a discharge port 22 that is open toward the outside. An underwater motor 3 is installed in the upper center of the casing 2 via a speed reducer 4, and an output shaft 5 of the underwater motor 3 is provided so as to project inside the casing 2. Further, a downward water feeding impeller 7 composed of so-called rearward vanes is rotatably coupled to the output shaft 5 coaxially with the output shaft 5. A rotary cone 6 having a wall surface opened downward is rotatably coupled to the output shaft 5 and the impeller 7 at the lower part of the impeller 7 so as to be rotatable between the wall surface of the rotary cone 6 and the casing 2. In addition, an annular flow path for the water to be treated 10 to be fed downward is defined.

The wall surface of the rotary cone 6 is formed with an inclination angle that does not increase the pressure loss of the water flow flowing from the upper side to the lower side in the annular flow path. That is, it is provided so that the angle θ formed by the wall surface of the rotating cone 6 with respect to the horizontal plane is larger than 60 °, preferably in the range of 60 ° <θ ≦ 85 °. Here, when the height of the rotating cone 6 and the diameter of the upper wall are the same as those in the conventional case, the outer shape and weight of the rotating cone 6 are smaller and lighter than those in the conventional case, and the rotation moment of the rotating cone 6 and the output shaft are reduced. The axial load supported by 5 is
It can be smaller than before.

The body of the casing 2 facing the wall surface of the rotary cone 6 is formed substantially parallel to the wall surface of the rotary cone 6, and the annular flow path between the wall surface of the rotary cone 6 and the body of the casing 2 is a horizontal plane. The angle formed with respect to is the same as the above θ. Therefore, when the cross-sectional area of the flow path in this portion is the same as that of the conventional case, the outer diameter of the body of the casing 2 may be smaller.

The tip of the opening of the wall surface of the rotary cone 6 is located slightly above the bottom of the casing 2, and an annular air ejection gap 61 is formed between this tip and the bottom of the casing 2. There is. The inner space surrounded by the rotary cone 6 and the bottom of the casing 2 is an air chamber 8 to which air is supplied. The pipe end of the air supply pipe 9 for supplying air is installed in the air chamber 8 so as to penetrate the bottom of the casing 2 and coaxial with the rotary cone.

FIG. 2 is a schematic diagram showing the operating condition of the aeration apparatus 1 configured as described above. The aeration device 1 is
For example, as shown in FIG. 2, it is immersed in water to be treated 10 containing sludge made of aerobic microorganisms stored in a biological reaction tank 40, and air is supplied from a blower 50 through an air supply pipe 9. Then, the submersible motor 3 shown in FIG. 1 is rotated, and the rotation is reduced to a predetermined speed by the speed reducer 4, transmitted to the output shaft 5, and coupled to the impeller 7 coupled to the output shaft 5 and a lower portion of the impeller 7. The rotated cone 6 is rotated. By the rotation of the impeller 7, the water to be treated 10 is taken vertically downward into the casing 2 from the water inlet 21, and a downward water flow is generated in the annular flow path. As described above, the angle θ formed by the wall surface of the rotating cone 6 with respect to the horizontal plane is larger than 60 °, and the water pressure of the water stream received by the wall surface is extremely smaller than in the conventional case. For example, if the θ of the conventional rotary cone 16 is 45 ° and the θ of the rotary cone 6 of the present embodiment is slightly higher than 60 °, the component of the force acting vertically on the wall surface of the rotary cone 6 by the water flow, That is, the drag force is about 67% of the conventional value. If the height of the rotating cone 6 is the same as that of the conventional one, the water pressure received by the entire wall surface of the rotating cone 6 is 4 times that of the conventional one in consideration of the area of the wall surface.
It will be about 0%. When θ in this embodiment is larger, the water pressure applied to the wall surface of the rotating cone 6 is further reduced. Also,
The angle of the annular flow path around the wall surface of the rotating cone 6 with respect to the horizontal plane is the same as that of the wall surface of the rotating cone 6, and the annular flow path is outside from immediately below the impeller 7 to a position near the air ejection gap 61. The shape of the annular flow path, which is one of the causes of pressure loss, is hardly changed because the shape of the flow path is not greatly curved toward the side.

On the other hand, the air blown into the air chamber 8 from the air supply pipe 9 once stays in the air chamber 8 and is thereafter jetted from the air jetting gap 61 to the annular flow passage. At that time, it is rolled by the centrifugal force of the rotating cone 6 rotating at a high speed to form a thin film. At this time, θ of the wall surface of the rotating cone 6 is 6
Since it is 0 °, which is larger than in the conventional case, when air moves along the wall surface to the air ejection gap 61,
When ejected from the sheet, the pressing force exerted on the air from the inner surface of the wall surface increases, and the air is further rolled into a thinner film. The thin film of air is sheared by the peripheral end of the rotary cone 6 and jetted into the annular flow path, and is crushed by crossing the water flow from above the annular flow path. The water force of the water flow here is not substantially diminished, and the air is mixed with the water flow in the form of sufficiently finely divided bubbles and is transferred as a gas-water multiphase flow to the downstream side to be discharged from the discharge port 22 of the casing 2. To be done. Then, a circulating flow of the air-water mixed phase flow 30 as shown by a broken line with an arrow in FIG. 2 is generated in the biological reaction tank 40, and sufficient oxygen is maintained to maintain the decomposition reaction of the water 10 to be treated by the aerobic microorganisms. It is replenished to the whole water 10 to be treated.

Here, the rotating cones 6 having different angles of θ are used, and the angle formed by the water flow at the position of the air ejection gap 61 with respect to the horizontal plane is made equal to the angle θ of each rotating cone 6. Then, the pressure loss in the flow path, the flow velocity, and the bubble mixing degree (void ratio) in the gas-water multiphase flow were tested and measured. When θ was 60 ° or less, the bubbles were made smaller than before. There is no big difference in performance, and when θ is greater than 60 °, the pressure loss in the flow path is reduced and the flow velocity becomes significantly faster.
It was confirmed that the bubble miniaturization performance was remarkably improved.

According to the aeration apparatus 1 thus constructed, the wall pressure of the rotary cone 6 is extremely small as compared with the conventional pressure, and the annular flow path is formed around the wall surface of the rotary cone 6 as in the conventional case. Does not significantly bend outwards, so that the pressure loss in the annular flow path is significantly reduced compared to the prior art. As a result, the circulation flow rate of the water to be treated 10 can be increased, the flow velocity in the flow path is increased, and the air is easily crushed, so that the air refining performance can be improved.

Further, since the pressing force from the inner surface of the wall surface of the rotary cone 6 that acts on the air supplied below the rotary cone 6 is increased, when it is jetted from the air jet gap 61, it is rolled and becomes a thinner film. It is said that Therefore, the jetted air is more easily crushed by the water flow, and the air refining performance can be further improved.

Further, due to the above effects, it is possible to reduce power energy such as electric power required to achieve the circulation flow rate and the air refining performance equivalent to those in the conventional case.

In addition, since the rotary cone 6 can be made smaller than the conventional one, the outer diameter of the body portion of the casing 2 can be made small in order to secure the flow passage having the same cross-sectional area as the conventional one. Therefore,
There is an advantage that the device can be made smaller than the conventional one.

FIG. 3 is a schematic vertical sectional view showing another embodiment of the aeration apparatus of the present invention, and is an enlarged view showing a part of the rotary cone 6 and the discharge port 22. In the aeration apparatus 1 of the present embodiment shown in FIG. 3, the angle θ1 formed by the rotary cone 6 with respect to the horizontal plane is about 65 °, and the casing 2 includes the wall surface of the rotary cone 6 and the casing 2 body. The annular flow path between the two is formed so as to form an angle of about 65 ° with the horizontal plane. The arrangement of the other members is the same as that of the aeration apparatus 1 shown in FIG. 1, and thus the description thereof is omitted here.

Here, as shown in FIG. 3, the vertical length of the opening of the discharge port 22 is W [mm], the horizontal line passing through the vertical center of the discharge port 22 and the lower end position of the peripheral edge of the opening of the rotary cone 6 (that is, When the vertical distance from the horizontal line passing through the upper end position of the air ejection gap 61) is Dv [mm], the aeration apparatus 1 of the present embodiment has a relationship of | Dv | ≦ W × 0.2, The discharge port 22 of the casing 2 is located on a substantially horizontal extension line of the air ejection gap 61. In addition, the inner diameter of the body portion of the casing 2 opposite to the peripheral end of the impeller 7 is R
[Mm], the horizontal distance between the vertical perpendicular of the inner wall surface of the casing 2 body and the vertical perpendicular passing through the peripheral position of the lower end of the opening of the rotary cone 6 (that is, the peripheral end position of the air ejection gap 61) is Dh [mm] ] | Dh | ≦ R × 0.1
The relationship is established, and the vertical position of the vertical wall of the wall surface of the body of the casing 2 and the air ejection gap 61 are substantially the same. Further, the above relationship is preferably | Dh | ≦ R
× 0.05, more preferably | Dh | ≦ R × 0.0
It is desirable that 1 is satisfied.

According to the aeration apparatus 1 having such a configuration, the casing 2 is provided on a substantially horizontal extension line of the air ejection gap 61.
Since the discharge port 22 is positioned, the thin film of air ejected from the air ejection gap 61 always intersects with the water flow, and is reliably crushed. As a result, the atomization of air is stably and reliably performed. Further, since the jetted air always intersects with the water flow, it becomes difficult for the air to flow backward against the water flow and float to the upstream side of the flow path, so that the pressure loss in the flow path due to the air flow is reduced. Therefore, the circulation flow rate can be further increased, the flow velocity can be increased, and the air refining performance can be further improved. Furthermore, since it becomes difficult for the air to float to the upstream side, it is difficult for the air to dissipate outside the discharge port 22, and thus it is possible to prevent the amount of air discharged from the discharge port 22 from decreasing.

In addition, the vertical position of the vertical wall of the body wall surface of the casing 2 and the air ejection gap 61 are substantially the same, and the air ejection gap 61 is located closer to the center of the casing 2 than the case where the ejection is performed. Since the generated air becomes counter to the water flow and becomes more difficult to float on the upstream side of the flow path, the pressure loss in the flow path due to the air flow becomes negligibly small. as a result,
The circulation flow rate can be further increased and the flow velocity can be increased to further improve the air refining performance. Further, as compared with the case where the air ejection gap 61 is located closer to the outer periphery of the casing 2, the ejected air thin film is more likely to cross the water flow, and thus the air is more likely to be crushed by the water flow. The conversion performance can be further improved. Furthermore, since it is more difficult for the air to float to the upstream side, it is more difficult for the air to dissipate to the areas other than the discharge port, and therefore it is possible to further prevent the air discharged from the discharge port from decreasing.
In addition, the positional relationship between the air ejection gap 61 and the discharge port 22,
Since the positional relationship between the air ejection gap 61 and the inner surface of the body of the casing 2 is optimized, the length L of the discharge portion shown in FIG.
[Mm] and the angle formed by the flow path in this portion with the horizontal plane can be easily optimized. As a result, the device design is simplified and the design period can be shortened. The operational effect produced by the angle θ1 formed by the rotary cone 6 with respect to the horizontal plane is the same as that of the aeration apparatus 1 shown in FIG. 1, and the description thereof is omitted here.

FIG. 4 is a schematic vertical sectional view showing still another embodiment of the aeration apparatus of the present invention, which is an enlarged view of a part of the rotary cone 6 and the discharge port 22. In the aeration device 1 shown in FIG. 4, the guide plate 62 extends over the entire periphery of the opening of the rotary cone 6, that is, the lower end of the wall surface of the rotary cone 6.
Are formed so as to project toward the annular flow path side. The guide plate 62 is smoothly extended from the wall surface of the rotary cone 6 toward the flow path with a gentle inclination, and there is no obstacle at the boundary between the guide plate 62 and the air jet. The gap between the peripheral end of the guide plate 62 and the bottom of the casing 2 is the air ejection gap 61. The arrangement of the other members is the same as that of the aeration apparatus 1 shown in FIG. 1, and thus the description thereof is omitted here.

According to the aeration apparatus 1 thus constructed, the air supplied from below the rotary cone 6 moves downward along the wall surface of the rotary cone 6 and is guided to the guide plate 62 to eject air. Toward the gap 61, a thin film is ejected into the flow path while being sheared by the rotating cone 6 rotating at high speed. Further, as compared with the rotating cone 6 having the same minimum diameter and maximum diameter and not having the guide plate 62, the angle θ2 formed by most of the wall surface of the rotating cone 6 with respect to the horizontal plane is made larger to make the wall surface of the rotating cone 6 Since the width of the peripheral flow passage can be expanded, the pressure loss in the flow passage can be further reduced. Therefore, the circulation flow rate can be further increased, the flow velocity of the water flow can be increased, and the atomization performance of the air can be further improved. Furthermore, the angle θ
2 can be made larger, and the pressing force from the inner surface of the wall surface of the rotary cone 6 that acts on air can be further increased. Therefore, when the air is ejected from the air ejection gap 61, the air is further rolled and a thinner film shape is formed. Can be Therefore, it is possible to further improve the atomization performance of air. Further, the operational effect obtained by optimizing the positional relationship among the air ejection gap 61 and the discharge port 22 and the inner surface of the casing 2 body is the same as that of the aeration device 1 shown in FIG. 3, and the description thereof is omitted here. To do.

Next, in the aeration apparatus 1 according to the present invention,
Based on the DO sensor that detects the dissolved oxygen (Dissolved Oxygen; hereinafter simply referred to as DO) concentration of the water to be treated in time series, and the DO concentration value output from this DO sensor, the power supply frequency of the submersible motor 3 An example will be described in which a DO control system including a rotation speed control unit that adjusts the rotation speed of the submersible motor 3 by changing the above is connected to perform the rotation speed control operation of the submersible motor 3.

The amount of organic matter to be treated contained in the water 10 to be treated contained in the above-mentioned biological reaction tank 40 (see FIG. 2) varies depending on its generation source, generation time (season) and amount of water. It also changes depending on the time of day and seasonal changes in water temperature. Therefore, the amount of oxygen consumed by the aerobic microorganisms introduced into the water to be treated 10 changes in accordance with the change in the amount of organic matter. Therefore, it is desirable to increase or decrease the amount of oxygen supplied to the water to be treated 10 in accordance with the amount of oxygen consumption to improve the efficiency and labor of the treatment. For this purpose, it is necessary to operate while controlling the rotation speed of the submersible motor 3, that is, the output of the aeration device 1 according to the required oxygen amount.

In the aeration apparatus 1 equipped with the above DO control system, the DO value is measured by the DO sensor immersed in the water 10 to be treated and output to the rotation speed control means. The rotation speed control means is preset with a parameter value for determining the rotation speed of the submersible motor 3 corresponding to the DO value, and the parameter value corresponding to the measured DO value is the power supply frequency of the submersible motor 3. Is output to, for example, an inverter circuit or the like, and the submersible motor 3 is driven at a power supply frequency corresponding to the parameter value.

When the power supply frequency is increased, the rotational speeds of the submersible motor 3 and the impeller 7 are increased, and the treated water 10
The circulation flow rate is increased to improve the stirring performance, the flow velocity in the casing 2 is increased, the air crushing effect is increased, and the air is further miniaturized to increase the oxygen supply amount. If the number of rotations of the submersible motor 3 is the same, the atomization performance of air is superior to the conventional one, so that the aeration apparatus 1 of the present invention has a larger oxygen supply amount. Moreover, when the power supply frequency is lowered, the rotation speeds of the submersible motor 3 and the impeller 7 are lowered, and the circulation flow rate of the water 10 to be treated is lowered. In this case, the flow velocity in the casing 2 decreases, and compared with the case where the flow velocity is high,
The effect of crushing bubbles is reduced and the oxygen supply amount is suppressed. In this way, the upper limit value of the oxygen supply amount with respect to the change in the rotation speed of the submersible motor 3 becomes larger than that in the conventional case,
The fluctuation range (dynamic range) of the oxygen supply amount is expanded as compared with the conventional case.

According to the aeration apparatus 1 thus constructed, even if the output of the submersible motor 3 is the same as the conventional one, the amount of oxygen supplied to the water to be treated 10 is higher because the air atomizing performance is higher than the conventional one. Since the DO in the water to be treated 10 can be maintained at a relatively high concentration, the accuracy and precision in measuring the DO value are improved, and the operation control of the device based on the DO value is facilitated. Further, since the fluctuation range (dynamic range) of the oxygen supply amount with respect to the change in the rotation speed of the submersible motor 3 is expanded, the DO control margin is increased and the control becomes easier.

The aeration apparatus 1 of each of the above-mentioned embodiments
Is not limited to air and may be another gas. For example, when the water to be treated 10 requires oxygen supply such that it is treated by an aerobic biological reaction, a gas containing oxygen may be used. Further, in the aeration apparatus 1 shown in FIG. 3, the relationship of | Dv | ≦ W × 0.2 is established, but if the relationship of | Dv | ≦ W × 0.5 is established, the same is true. It produces a working effect.

[0038]

As described above, according to the aeration apparatus of the present invention, the following effects can be obtained. The pressure of the water flow on the wall of the rotating cone is smaller than before,
Moreover, unlike the conventional method, the flow path does not greatly bend around the wall surface of the rotating cone, and the pressure loss in the flow path is reduced, so the circulation flow rate of the treated water is increased and the flow speed is increased. As a result, the air is easily broken and the air refining performance can be improved.

Further, the pressing force from the inner surface of the wall surface of the rotary cone acting on the air supplied below the rotary cone is increased, and when it is jetted from the air jet gap, it is rolled to form a thinner film. The jetted air is more easily broken by the water flow, and the air refining performance can be further improved.

Further, due to the above-mentioned effects, it is possible to reduce power energy such as electric power required to achieve the circulation flow rate and the air refining performance equivalent to those in the conventional case.

In addition, the rotating cone can be made smaller than the conventional one, and the outer diameter of the casing body can be made small in order to secure the flow passage having the same cross-sectional area as the conventional one. There is an advantage that it can be miniaturized.

Further, the discharge port of the casing is located on a substantially horizontal extension line of the air ejection gap, and the thin film of air ejected from the air ejection gap always crosses the water flow and is reliably crushed. Therefore, it becomes possible to stably and surely miniaturize the air. Furthermore, the jetted air, which always crosses the water flow, goes against the water flow and is less likely to float upstream of the flow path, reducing the pressure loss in the flow path due to the air flow. Can be further increased, the flow velocity can be increased, and the air refining performance can be further improved. Furthermore, since it is more difficult for air to float upstream, and air is less likely to dissipate outside the discharge port,
It is possible to prevent the air discharged from the discharge port from decreasing.

Further, the vertical position of the vertical line on the wall surface of the body of the casing and the horizontal position of the air ejection gap are substantially the same, and the ejected air is more likely to be discharged than when the air ejection gap is located closer to the center of the casing. It becomes more difficult to float in the upstream side of the flow path against the water flow, and the pressure loss in the flow path due to the air flow becomes negligibly small, so the circulation flow rate can be further increased and the flow velocity can be increased to increase the air flow. The miniaturization performance can be further improved. Furthermore, compared with the case where the air ejection gap is located closer to the outer periphery of the casing, the thin film of ejected air easily crosses the water flow and is more likely to be crushed by the water flow, further improving the air refining performance. can do. Furthermore, since it becomes more difficult for the air to float to the upstream side and the air is more difficult to dissipate outside the discharge port, it is possible to further prevent the air discharged from the discharge port from decreasing.

In addition, as a concrete structure of the aeration device,
If a configuration is adopted in which a guide plate protruding toward the flow path is provided on the peripheral portion of the rotating cone, the angle θ is made larger than that of a rotating cone having the same minimum and maximum diameters and no guide plate. Since the width of the flow passage around the wall surface of the rotating cone can be expanded to further reduce the pressure loss in the flow passage, the circulation flow rate can be further increased, and the flow velocity of the water flow can be increased to further improve the air refining performance. Can be improved. Further, by making the angle θ larger, the pressing force exerted on the air from the inner surface of the wall surface of the rotary cone is further increased, and when the air is ejected from the air ejection gap, the air is further rolled and becomes thinner. Since it can be formed into a film, it becomes possible to further improve the air refining performance.

[Brief description of drawings]

FIG. 1 is a schematic vertical sectional view showing an embodiment of an aeration apparatus of the present invention.

FIG. 2 is a schematic diagram showing an operating condition of an embodiment of the aeration device of the present invention.

FIG. 3 is a schematic vertical cross-sectional view showing another embodiment of the aeration device of the present invention, and is an enlarged view showing a part of a rotary cone and a discharge port.

FIG. 4 is a schematic vertical cross-sectional view showing still another embodiment of the aeration device of the present invention, and is an enlarged view showing a part of a rotary cone and a discharge port.

FIG. 5 is a schematic vertical sectional view showing an example of a conventional aeration apparatus.

[Explanation of symbols]

1 ... Aeration device, 2 ... Casing, 3 ... Submersible motor (motor), 6 ... Rotating cone, 7 ... Impeller, 61 ... Air ejection gap, 62 ... Guide plate.

─────────────────────────────────────────────────── ─── Continuation of front page (56) References JP-A-11-221592 (JP, A) JP-A-64-18496 (JP, A) JP-B-25-25677 (JP, B2) (58) Field (Int.Cl. ⁷ , DB name) C02F 3/14-3/26 B01F 1/00-7/32

Claims (7)

(57) [Claims] 1. A rotating cone is disposed inside a casing having a flow passage formed therein, and is coaxially and integrally arranged with the impeller downstream of an impeller driven by a motor. An aeration device having an air ejection gap between a peripheral edge portion and an inner wall of the casing, wherein 60 ° <θ ≦ 85 ° , where θ is an angle formed by a wall surface of the rotating cone with respect to a horizontal plane . Aeration device characterized by being. 2. The outlet of the casing is opened outward in a substantially horizontal direction, the vertical length of the opening of the outlet is W [mm], and a horizontal line passing through the vertical center of the outlet. When the vertical distance from the horizontal line passing through the lower end position of the peripheral edge of the opening of the rotating cone is Dv [mm], the relationship of | Dv | ≦ W × 0.5 is established. Item 1. An aeration device according to item 1. 3. The inner diameter of the casing body opposite to the peripheral end of the impeller is R [mm], and passes through the vertical perpendicular line of the inner wall surface of the casing body and the peripheral position of the lower end of the opening of the rotary cone. The aeration apparatus according to claim 1 or 2, wherein a relationship of | Dh | ≦ R × 0.1 is established when a horizontal distance from the vertical perpendicular is Dh [mm]. 4. The aeration apparatus according to claim 1, wherein the rotary cone has a guide plate projectingly provided on a flow path side at a peripheral edge of an opening thereof. 5. Inside a casing having a flow passage formed therein.
Downstream of the impeller installed and driven by the motor
On the side, the rotating cone is coaxially and integrally with the impeller.
Arranged around the periphery of the rotating cone and the casing
It is an aerator that has an air ejection gap between it and the inner wall.
hand, The angle formed by the wall surface of the rotating cone with respect to the horizontal plane is θ
Is 60 ° <θ ≦ 85 °, A space below the rotary cone is supplied to which air is supplied.
The uppermost surface of the bottom wall of the casing is
At the same level in the vertical direction as
The An aeration device characterized by the above. 6. A casing having a flow passage formed therein,
Downstream of the impeller installed and driven by the motor
On the side, the rotating cone is coaxially and integrally with the impeller.
Arranged around the periphery of the rotating cone and the casing
It is an aerator that has an air ejection gap between it and the inner wall.
hand, The angle formed by the wall surface of the rotating cone with respect to the horizontal plane is θ
Is 60 ° <θ ≦ 85 °, Body of the casing facing the wall of the rotating cone
Is formed substantially parallel to the wall surface of the rotating cone, An aeration device characterized by the above. 7. The wall surface of the rotating cone is a tapered surface.
The 7. The method according to claim 1, wherein
Aeration device.