JP3629979B2 - Underwater stirrer - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an underwater agitation device, and in particular, for agitation of water to be treated in a deep water tank in which a microbial carrier is added to the tank in order to increase the concentration of microbial cells in the tank in the field of water treatment. The present invention relates to a suitable underwater stirring device.
[0002]
[Prior art]
Conventionally, an underwater agitating aeration apparatus installed in the water to be treated in a water tank for the purpose of supplying air to microbial cells is a top opening of water sucked up from a lower opening of a draft pipe by rotating one pump blade. The air was aerated during exhalation from the air, and the air was mixed and dissolved in water. Thereby, the water discharged as an upward flow from the upper opening of the draft pipe descends on the outside of the draft pipe and descends to form a circulating flow sucked from the lower opening of the draft pipe. Therefore, water in which air is dissolved can be evenly diffused in the water tank.
[0003]
[Problems to be solved by the invention]
By the way, in order to increase the concentration of microbial cells, when a microbial carrier in which microorganisms are immobilized is put into a water tank, the microbial carrier to be settled in the water tank is levitated to maintain a uniform carrier concentration in the water tank. This is particularly important in the case of deep tank water tanks.
[0004]
However, in the case of a conventional underwater agitating aeration apparatus, the water to be treated flowing outside the draft pipe is a downward flow, so that a force in the direction of settling acts on the microorganism carrier that must be floated. Therefore, there is a disadvantage that the microbial carrier is precipitated at the bottom of the water tank.
Furthermore, if the microorganism carrier is sucked up from the lower opening of the draft pipe so as not to settle, a large upward flow must be generated in the draft pipe by the pump blade, which increases the power cost.
[0005]
In addition to the underwater stirring type aeration apparatus, it is problematic in terms of apparatus cost to provide a stirring apparatus that floats the microorganism carrier.
The present invention has been made in view of such circumstances, can efficiently stir the inside of the water tank, and can prevent the microbial carrier from precipitating at the bottom of the water tank even when the microbial carrier is put into the water tank. It aims at providing an underwater stirring apparatus.
[0006]
[Means for Solving the Problems]
In order to achieve the above object, the present invention provides a first pump blade that is submerged in a water tank, sucks the water in the water tank into the casing from the suction port, and discharges the water upward from the upper discharge port. A pump device having a second pump blade for discharging water downward from the lower discharge port, and an intake port for taking in the downward flow discharged downward from the lower discharge port in the vicinity of the lower discharge port And a cylindrical body formed with a discharge port for discharging the downward flow in the vicinity of the bottom of the water tank.
[0007]
According to the present invention, the upper part of the water tank is mainly stirred by the upward flow formed by the first pump blades, while the downward flow formed by the second pump blades is guided into the cylinder and discharged from the vicinity of the bottom of the water tank. By doing so, an upward flow is formed outside the cylindrical body. Thereby, the lower part in the water tank can be mainly stirred by the second pump blade, and an upward flow is formed outside the cylindrical body. Therefore, when the microbial carrier is put into the water tank, It is possible to prevent precipitation at the bottom of the water tank.
[0008]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, preferred embodiments of an underwater stirring device according to the present invention will be described in detail with reference to the accompanying drawings.
FIG. 1 is a side cross-sectional view in which an underwater agitation apparatus 10 according to the present invention is disposed in a water tank 12, and a large number of microbial carriers 14, 14,... With aerobic microorganisms, for example, nitrifying bacteria immobilized therein. The case where the water to be treated is added and treated in the water tank 12 will be described below.
[0009]
As shown in FIG. 1, the underwater agitation device 10 mainly includes a pump device 16 that is submerged in a water tank 12 and a cylinder (hereinafter referred to as “draft pipe 18”) that is disposed near the lower portion of the pump device 16. And an air nozzle 20 for supplying air into the pump device 16.
In the pump device 16, two upper and lower pump blades 28 and 30 are provided on the same rotating shaft 32 in a vertical cylindrical casing 26 having an upper discharge port 22 at the upper end and a lower discharge port 24 at the lower end. At the same time, a suction port 34 is formed at a substantially intermediate position between the two pump blades 28 and 30 on the side surface of the casing 26.
[0010]
A motor 36 for rotating the pump blades 28 and 30 is connected to the upper end of the rotary shaft 32, and the first pump blade 28 disposed on the upper side of the rotary shaft 32 rotates in the water tank 12. The shape of the blade is formed so that water is sucked into the casing 26 from the suction port 34 and discharged upward from the upper discharge port 22. On the other hand, the second pump blade 30 disposed on the lower side of the rotating shaft 32 has a blade shape so that the treated water sucked from the suction port 34 is discharged downward from the lower discharge port 24 when rotated. It is formed.
[0011]
Further, a ring-shaped eaves member 38 is attached to the periphery of the upper discharge port 22, and a Jinkasa diffusion plate 33 for diffusing the water to be treated discharged upward is disposed above the upper discharge port 22. The
The air nozzle 20 is disposed between the first pump blade 28 and the second pump blade 30 and passes through the casing 26 and is connected to a compressor (not shown).
[0012]
The draft pipe 18 is formed in a cylindrical shape that is thicker than the diameter of the casing 26 of the pump device 16, and the lower end discharge port 24 of the casing 26 slightly enters the draft pipe 18 from the intake port 40 that opens at the upper end of the draft pipe 18. Arranged to be inserted. The lower end of the draft pipe 18 is located in the vicinity of the bottom of the water tank 12, and a discharge port 42 for discharging the water to be treated taken from the intake port 40 is formed at the lower end.
[0013]
In addition, a raw water pipe 44 for supplying water to be treated into the water tank 12 is disposed in the lower part of the water tank 12, and a trough 46 is provided at the upper peripheral edge of the water tank 12. Then, the treated water treated by contacting the treated water and the microorganism carrier 14 in the water tank 12 overflows from the upper edge of the water tank 12 to the trough 46 by the air lift action of the air aerated from the air nozzle 20.
[0014]
Next, the operation of the underwater agitator configured as described above will be described.
While the first and second pump blades 28 and 30 are rotated, the water to be treated in the water tank 12 is sucked into the casing 26 from the suction port 34 and air is aerated from the air nozzle 20 into the casing 26. Thereby, air is mixed and dissolved in the water to be treated. A part of the water to be treated in which air is mixed and dissolved is discharged upward from the upper discharge port 22 by the first pump blade 28 and diffused by the diffusion plate 33, and combined with the rising force of the bubbles from the air nozzle 20, the water tank It rises in 12 as an upward flow. Due to the upward flow by the first pump blade 28, the upper part in the water tank is mainly stirred.
[0015]
The remainder of the water to be treated in which air is mixed and dissolved is discharged downward from the lower discharge port 24 by the second pump blade 30. The water to be treated discharged downward is taken into the draft pipe 18 from the intake 40 of the draft pipe 18 and descends in the draft pipe 18 as a downward flow. Due to the ejector effect caused by the downward flow in the draft pipe, water to be treated around the draft pipe 18 is sucked from the intake port 40 of the draft pipe 18. The downward flow descending in the draft pipe 18 is discharged from the discharge port 42 toward the bottom of the water tank 12, hits the bottom of the water tank 12, changes direction, and forms an upward flow that rises outside the draft pipe 18. Thereby, the lower part in the water tank 12 can be mainly stirred by the second pump blade 30. In addition, since an upward flow is formed outside the draft pipe 18, the microbial carrier 14 can be prevented from being precipitated at the bottom of the water tank 12.
[0016]
Further, in the case of the underwater agitation apparatus 10 of the present invention, the outside of the draft pipe 18 is an upward flow, so that a large amount of power is not required to prevent the microbial carrier 14 from being precipitated as in the prior art. Therefore, the running cost can be reduced.
In the embodiment of the present invention, the air nozzle 20 is provided in the pump device 16 and air is mixed and dissolved in the water to be treated. However, for an anaerobic tank that does not need to mix and dissolve air in the water to be treated. It can also be used as an underwater stirring device.
[0017]
【The invention's effect】
As described above, according to the underwater agitation apparatus of the present invention, the inside of the water tank can be efficiently stirred, and even when the microbial carrier is introduced into the water tank, the microbial carrier can be prevented from being precipitated at the bottom of the water tank. .
In addition, as in the prior art, since a large amount of power is not required in order not to precipitate the microorganism carrier, the running cost can be reduced.
[Brief description of the drawings]
FIG. 1 is a side cross-sectional view of an underwater stirring device of the present invention disposed in a water tank.
DESCRIPTION OF SYMBOLS 10 ... Underwater stirring apparatus 12 ... Water tank 14 ... Microorganism carrier 16 ... Pump apparatus 18 ... Draft pipe 20 ... Air nozzle 22 ... Upper discharge outlet 24 of casing ... Lower discharge outlet 26 of casing ... Casing 28 ... First pump blade 30 ... Second pump blade 33 ... Diffuser plate 34 ... Suction port 40 ... Draft pipe inlet 42 ... Draft pipe outlet 44 ... Raw water piping

Claims (3)

A first pump blade that is submerged in the water tank, sucks the water in the water tank into the casing from the suction port and discharges the water upward from the upper discharge port, and discharges the sucked water downward from the lower discharge port. A pump device having a second pump blade;
An intake port for taking in the downward flow discharged downward from the lower discharge port is formed in the vicinity of the lower discharge port, and a discharge port for discharging the downward flow is formed in the vicinity of the bottom of the water tank Cylinders made,
An underwater stirring apparatus comprising: 2. The underwater agitation device according to claim 1, wherein an air nozzle for blowing air is disposed between the first pump blade and the second pump blade. The underwater agitation device according to claim 1, wherein a diffusion member for diffusing upward flow discharged upward from the upper discharge port is provided above the upper discharge port of the pump device.

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