JP2002018259A - Aerator - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an aerator capable of efficiently aerating water on the bottom part of an aeration tank while sucking up the same in large quantities without increasing the shaft output of the aerator to perform the stirring and aeration of the whole of the aeration tank. SOLUTION: In the aerator constituted by attaching an aerating impeller 3 to a drive shaft 2 rotationally driven by a motor 1, the leading ends in the peripheral direction of the blades 32 of the impeller 3 are curved in the direction reverse to the rotary direction of the drive shaft 2 and the upper ends of the blades 32 are curved in the same direction as the rotary direction of the drive shaft 2.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an aerator and, more particularly, to a water tank at the bottom of an aeration tank installed in a sewage or sewage treatment plant without increasing the axial output of the aerator. The present invention relates to an aerator capable of efficiently increasing the amount of water to be sucked up, thereby enabling stirring and aeration of the entire aeration tank.

[0002]

2. Description of the Related Art Conventionally, as an aerator installed in a sewage or sewage treatment plant, an aerator having an impeller 3 attached to a drive shaft 2 as shown in FIGS. I have. The aerator B ′ rotates the drive shaft 2 by the motor 1 via the speed reducer 6, and attaches an aeration impeller 3 to the lower end of the drive shaft 2. The impeller 3 is shown in FIG. As described above, the linear blades 35 are radially arranged on the drive shaft 2 at equal intervals (in this example, 90 °), and the adjacent blades 35 are connected to each other by the connecting plate 36. It is composed. The impeller 3 is connected to the motor 1
Is rotated through the speed reducer 6 and the drive shaft 2 to agitate and aerate water in the aeration tank.

[0003]

In the above-mentioned conventional aerator B ', the aeration impeller 3 is constructed by arranging radially linear blades 35 on the drive shaft 2. Therefore, when the impeller 3 rotates, a large amount of water resistance is applied to the blades 35, and when the rotational speed of the impeller 3 is to be increased, the axial output of the aerator B ′ is significantly increased. It is difficult to increase the suction water volume due to the rotation of the car 3, especially in the case of an aeration tank having a large water depth, the flow velocity at the bottom of the aeration tank is small. There was a problem that it was not refluxed to the upper part of the tank, and that the entire aeration tank could not be stirred or aerated.

The present invention has been made in consideration of the above-mentioned problems of the conventional aerator, and has been made to efficiently increase the amount of water sucked up at the bottom of the aeration tank without increasing the axial output of the aerator. It is an object of the present invention to provide an aerator capable of performing agitation and aeration of the entire aeration tank.

[0005]

In order to achieve the above object, an aerator according to the present invention is an aerator having an aeration impeller mounted on a drive shaft rotated by a motor. The circumferential tip is curved in a direction opposite to the rotation direction of the drive shaft, and the upper end of the blade is curved in the same direction as the rotation direction of the drive shaft.

In this aerator, the tip of the impeller blade in the circumferential direction is curved in a direction opposite to the rotation direction of the drive shaft, and the upper end of the blade is curved in the same direction as the rotation direction of the drive shaft. Therefore, when the impeller rotates, large water resistance is less likely to be applied to the blade, and the rotation speed of the impeller can be increased without increasing the shaft output of the aerator. The amount of suction water can be increased.

In this case, it is possible to provide an up-down adjusting device for switching the installation position of the impeller up and down between aerobic operation and anaerobic operation.

[0008] Thus, by switching the installation position of the impeller up and down, aerobic operation and anaerobic operation can be performed using one aerator.

In addition, a water guide pipe can be provided below the impeller.

[0010] Thereby, the water at the bottom of the aeration tank can be reliably sucked up without increasing the axial output of the aerator through the water pipe, and even in the case of the aeration tank having a large water depth,
By increasing the flow velocity at the bottom of the aeration tank, stirring the entire aeration tank,
Aeration can be performed uniformly and efficiently.

[0011]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the aerator according to the present invention will be described below with reference to the drawings.

1 to 4 show an embodiment of the aerator according to the present invention. The aerator B is installed on the upper part of the aeration tank A. The drive shaft 2 is rotated by the motor 1 via the vertical adjustment device 6 also serving as a speed reducer, and the lower end of the drive shaft 2 is aerated. And the impeller 3 is attached to the drive shaft 2
Radially and at equal intervals (120 ° in this example)
In addition, a blade 32 is provided, and adjacent blades 32 are connected to each other by a connection plate 31.

The blades 32 of the impeller 3 radially and equidistantly arranged on the drive shaft 2 are arranged such that the tip of the blade 32 in the circumferential direction is aligned with the rotational direction of the drive shaft 2 as shown in FIG. The blade 32 is bent in the opposite direction, and the upper end 33 of the blade 32 is bent in the same direction as the rotation direction of the drive shaft 2 as shown in FIG. Thereby, when the impeller 3 rotates, it is difficult for the large water resistance to be applied to the blade 32, and the aerator B
The rotation speed of the impeller 3 can be increased without increasing the shaft output, and the amount of water drawn by the rotation of the impeller 3 can be increased.

An up-down adjusting device 6, which also serves as a speed reducer, is provided below the motor 1. The speed adjusting mechanism 6 has an arbitrary structure and a cylinder-type screw for switching the position of the impeller 3 up and down. The vertical position of the drive shaft 2 is constituted by a rod type, a link type, or the like, and the vertical position of the impeller 3 can be switched up and down by the vertical movement mechanism of the vertical adjustment device 6 which also serves as a reduction gear. I do.

Then, as shown in FIG. 1, the impeller 3
When the drive shaft 2 is rotated at the water surface position, aeration is performed by sucking water on the water surface from the center of the impeller 3 and discharging the water in the radial direction while stirring with air (aerobic operation). On the other hand, as shown in FIG. 4, when the drive shaft 2 is rotated while being arranged so as to be entirely submerged in water, water is sucked up from the center of the impeller 3 and discharged in the radial direction. The aerating machine B is configured to be able to selectively perform aerobic operation and anaerobic operation by using one aerator B.

In this case, the motor 1 can be set to a rotation speed suitable for aerobic operation or anaerobic operation by inverter control. In general, the rotation speed during anaerobic operation is It is desirable to set the rotation speed a little lower than the rotation speed at the time.

In particular, in the case of the aeration tank A having a large water depth, as shown in a modified example shown in FIG. 5, at the lower position where the impeller 3 is installed, immediately below the impeller 3 and at the bottom of the aeration tank A. A water pipe 5 having an opening can be provided. As a result, the water at the bottom of the aeration tank A can be reliably sucked up without increasing the axial output of the aerator B through the water guide pipe 5, and even in the case of the aeration tank A having a large water depth, the aeration tank A By increasing the flow velocity at the bottom of, stirring and aeration of the entire aeration tank A,
It can be performed more uniformly and efficiently.

Generally, the head (H) of a fluid machine (aerator) is roughly represented by the following equation (1). H = U · Vu / g (1) where, U: peripheral velocity Vu: peripheral component of absolute velocity The shaft power (P) is represented by the following equation (2). P = γ · Q · H (2) where γ: specific weight Q: flow rate

The flow at the blade outlet position of the aerator is shown in FIG. 6A (flow at the blade outlet position of the conventional aerator shown in FIG. 8) and FIG. (Flow at the blade exit position).

Equations (1) and (2) and FIGS. 6A and 6B
As is clear from FIG.
Is curved in the direction opposite to the rotation direction of the drive shaft 2, so that Vu2 is reduced and the lift (H) from the impeller 3 is reduced, so that the shaft output is the same. In this case, the flow velocity (Vm2) can be increased. Also,
Since the flow rate is increased, the amount of suction water is increased, and as a result, the flow velocity at the bottom of the aeration tank A is increased.
The whole stirring and aeration can be performed uniformly and efficiently.

In the anaerobic operation, the impeller 3 is arranged so as to be immersed in the water by the vertical adjustment device 4, so that the impeller 3 and the bottom of the aeration tank A (the water pipe 5 is disposed). In this case, the distance from the upper end of the water pipe 5 becomes shorter, and as a result, the flow velocity at the bottom of the aeration tank A increases, and the stirring and aeration of the entire aeration tank A can be performed more uniformly and efficiently. In addition, the rotation speed during the anaerobic operation can be set to a rotation speed slightly smaller than the rotation speed during the aerobic operation. Since the flow rate (Q) increases as the head (H) of 2) decreases, the stirring and aeration of the entire aeration tank A can be uniformly and efficiently performed without increasing the shaft output of the aerator. it can.

[0022]

According to the aerator of the present invention, the tip of the impeller blade in the circumferential direction is curved in the direction opposite to the rotation direction of the drive shaft, and the upper end of the blade is set in the same direction as the rotation direction of the drive shaft. When the impeller rotates, large water resistance is less likely to be applied to the blade, and the rotation speed of the impeller can be increased without increasing the shaft output of the aerator. The amount of water drawn by the rotation of the impeller can be increased, thereby increasing the flow velocity at the bottom of the aeration tank, especially in the case of a large aeration tank.
Agitation and aeration of the entire aeration tank can be uniformly and efficiently performed.

Also, by providing an up / down adjusting device for switching the installation position of the impeller up and down during aerobic operation and anaerobic operation, one unit can be installed by switching the installation position of the impeller up and down. Aerobic driving and anaerobic driving can be performed using the aerator of the present invention.

Further, by disposing a water guide pipe below the impeller, the water at the bottom of the aeration tank can be reliably sucked up without increasing the axial output of the aerator through the water guide pipe. Even in the case of a deep aeration tank,
By increasing the flow velocity at the bottom of the aeration tank, stirring the entire aeration tank,
Aeration can be performed more uniformly and efficiently.

[Brief description of the drawings]

FIG. 1 is a front view showing an embodiment of an aerator according to the present invention.

FIG. 2 is a plan view of the same.

FIG. 3 is a detailed view of a main part of the blade as viewed from a direction C in FIG. 2;

FIG. 4 is an explanatory diagram showing an anaerobic operation.

FIG. 5 is a front view showing a modified example of the aerator of the present invention.

FIG. 6A is an explanatory diagram showing a flow at a blade outlet of a conventional aerator, and FIG. 6B is an explanatory diagram showing a flow at a blade outlet position of the aerator according to the embodiment of the present invention.

FIG. 7 is a front view showing a conventional aerator.

FIG. 8 is a plan view showing a conventional aerator.

[Description of Signs] A Aeration tank B Aerator 1 Motor 2 Drive shaft 3 Impeller 31 Connecting plate 32 Blade 4 Vertical adjustment device 5 Water pipe

──────────────────────────────────────────────────の Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) C02F 3/16 ZAB C02F 3/16 ZAB 3/22 3/22 Z (72) Inventor Manabu Takeuchi Amagasaki, Hyogo 3-11-1, Shimosakabe, Ichiba F-term (reference) 4D029 AA06 CC06 4G035 AB24 4G078 AA07 AB20 BA05 CA01 CA06 DA01 DB03 DB08

Claims (3)

[Claims] An aerator in which an aeration impeller is mounted on a drive shaft that is rotationally driven by a motor, wherein a circumferential tip of an impeller blade is curved in a direction opposite to a rotation direction of the drive shaft. And an upper end of the blade is curved in the same direction as the rotation direction of the drive shaft. 2. The aerator according to claim 1, further comprising an up-down adjusting device for switching the installation position of the impeller up and down during aerobic operation and anaerobic operation. 3. The aerator according to claim 1, wherein a water pipe is provided at a position below the impeller.