JPH0583319B2 - - Google Patents

Description

[Detailed Description of the Invention] [Field of Industrial Application] The present invention is designed to agitate various liquids, especially sewage water, and at the same time supply air into the liquid using the stirring water flow to perform aeration. This invention relates to an aeration device that prevents bubbles from penetrating into the intake port of a hollow shaft.

[Conventional technology]

As a so-called aeration device that supplies air while stirring sewage and other water and liquids, Japanese Patent Application Laid-Open No. 55-3851, Utility Model No. 55-3851,
There is one described in Publication No. 57-21098. This conventional aeration device has an excellent advantage in that it can supply air into the water by utilizing the negative pressure generated in the water by stirring the liquid, and can be performed using a single drive unit.

[Problem to be solved by the invention]

However, when aeration is performed while stirring the water by rotating the stirring blade, many air bubbles are generated near the water surface due to the stirring flow and air bubbles supplied into the water, and these bubbles multiply and cover the water surface. It becomes like this. These air bubbles on the water surface also enter the cover that covers the hollow shaft. This is because there is a negative pressure inside the hollow shaft and the cover, making it extremely easy for air bubbles on the water surface to enter, and the bubbles that enter the cover will eventually reach the intake port drilled at the top of the hollow shaft. , air supply may become impossible.

The present invention aims to prevent this.

[Means to solve the problem]

In order to achieve the above-mentioned object, the invention according to claim 1 attaches a stirring blade to the underwater part of a hollow shaft driven by a motor provided above the water, and utilizes the negative pressure generated by the rotation of the stirring blade. In an aeration device for blowing air into water, an air intake port is provided above the water surface of the hollow shaft, the motor and the air intake port are covered with a cover having an opening at the top, and the hollow shaft is provided at a position below the air intake port. The gist is that a seal is installed to close the gap between the shaft and the cover.

In addition, the invention as claimed in claim 2 provides that a stirring blade is attached to the underwater part of a hollow shaft driven by a motor provided above the water, and air is pumped into the water by using the negative pressure generated by the rotation of the stirring blade. In the blowing aeration device, an intake port is provided above the water surface of the hollow shaft, and a cover having an opening at the top extends from above the motor to the underwater part of the hollow shaft, and the air pressure inside the cover is increased. The gist is that a fan is attached to the motor.

[Effect]

According to the invention as claimed in claim 1, by disposing the seal that closes the gap between the hollow shaft and the cover at a position below the intake port, bubbles enter the cover that covers the hollow shaft and block the intake port. You can prevent this from happening.

Further, according to the invention as claimed in claim 2, a fan for increasing the air pressure inside the cover is attached to the motor, and by maintaining positive pressure at least in the vicinity of the intake port inside the cover, the air pressure inside the cover that covers the hollow shaft is increased. It is possible to prevent bubbles from entering and clogging the intake port.

〔Example〕

The aeration apparatus of the present invention will be explained below based on the illustrated embodiments.

FIG. 1 shows a first embodiment. In this first embodiment, 1 is a motor such as an electric motor or a hydraulic motor, and a hollow shaft 2 is connected to the drive shaft of this motor 1 directly or via a shaft coupling. The intake port 3, which is long enough to be immersed in the liquid to a required depth, and is bored at the top of the motor 1 and the hollow shaft 2, is always positioned above the water surface, and the lower end of the hollow shaft 2 is The stirring blade 4 is fixed, and the lower end of the hollow shaft is opened at the central tip position of the stirring blade 4.

Further, the motor 1 and the hollow shaft 2 are integrally covered with a cylindrical cover 5 on the outside. The cover 5 is provided with an opening 51 at the top so that air can be sucked in. This opening 51 is a cylindrical cover with a smaller diameter than the cover 52 covering the motor, to minimize damage to the motor caused by splashes from the liquid surface generated by wind and rain.

Furthermore, by providing a hose or the like in the opening 51, it is possible to completely prevent splashes. A cylindrical hollow shaft cover 53 that covers at least the intake port of the hollow shaft is provided,
A seal 9 is provided between the hollow shaft cover 53 and the hollow shaft at a position below the intake port 3.

In this embodiment, this seal 9 is an oil seal 9.
1, a split-shaped oil seal 92 and a V-seal 93,
Although the seal is composed of a seal cover 94 and a retaining ring 95, it is also possible to provide a seal with other configurations.

These seals 9 prevent bubbles traveling through the hollow shaft 2 and droplets from the surface from entering the intake port 3 of the hollow shaft 2, and smooth the sliding between the hollow shaft cover and the hollow shaft. It is something.

In this embodiment, after removing the motor cover 52, the motor 1, the hollow shaft 2, and the hollow shaft cover 5 are
3 are integrated into a structure that can be removed from the support base, making maintenance easy.

According to this embodiment described above, although negative pressure is generated around the intake port and therefore the motor, since the motor is isolated from the outside except for the opening 51 at the top, bubbles generated near the water surface are absorbed by the hollow shaft. It will not enter the air intake.

Further, FIGS. 2 and 3 show a second embodiment of the present invention. In the figure, unlike the first embodiment, the cover 5 extends into the water as in the conventional example.

In addition, a fan 6 is attached to the top of the motor 1,
As the motor 1 rotates, the fan 6 also rotates so that air can be forcibly drawn into the cover 5 through the opening 51, so that the pressure inside the cover 5 becomes higher than atmospheric pressure, that is, positive pressure. . This fan 6 can be used to cool the motor. Furthermore, it is possible to provide a fan 6 between the upper part of the intake port 3 of the hollow shaft 2 and the hollow shaft cover. Reference numeral 7 denotes a fan cover provided on the fan 6, and as shown in FIG. 2, this fan cover 7 is provided with a partition plate 8 on the outer periphery of the fan cover so as to close the space between the fan cover 7 and the inner surface of the cover 5. This prevents the air sucked into the motor 1 and the cover from the fan cover 7 from flowing back when the fan 6 rotates, and allows the air to flow in one direction. Positive pressure is maintained between the hollow shaft 2 and the inside of the cover 5.

The amount of air supplied to the fan 6 is sufficient to cool the motor, supply air to the intake port 3, and maintain a positive pressure in at least the vicinity of the intake port 3 within the cover 5.

Furthermore, as shown in FIG. 3, the partition plate 8 can be provided between the fan cover 7 and the opening 51 of the cover 5 to form a one-way inflow passage for sucking air. The embodiment shown in Fig. 3 is directly connected to the fan 6 from the intake port of the cover, so air can be taken in smoothly. cover 5
It has the effect of increasing the air pressure inside than the outside air pressure.

By keeping the pressure inside the cover 5 positive at all times, the pressure in the vicinity of the intake port 3 is higher than atmospheric pressure, which prevents bubbles from entering the cover 5 from the tip of the cover 5. 3, the amount of air to be supplied can be increased by utilizing the negative pressure in the liquid.

Further, in the third embodiment shown in FIG. 4, the fan 6 for cooling the motor is made large in diameter, and the outer peripheral part of the fan is inscribed almost in the inner peripheral surface of the cover 5 to prevent backflow of air within the cover 5. This embodiment has the same effects as the second embodiment.

A detailed explanation of the method of installing the aeration device in each embodiment of the present invention has been omitted, but the method is similar to the method of installing a conventional self-priming aerator.

〔Effect of the invention〕

Since the present invention is configured as described above, it has the following effects.

According to the aeration device according to the invention according to claim 1,
By arranging a seal that closes the gap between the hollow shaft and the cover at a position below the intake port, it prevents bubbles from entering the cover that covers the hollow shaft and blocking the intake port. Aeration can be carried out continuously.

Further, according to the aeration device according to the invention described in claim 2, a fan for increasing the air pressure inside the cover is attached to the motor, and by keeping at least the vicinity of the intake port inside the cover at a positive pressure, the hollow shaft is covered. This prevents bubbles from entering the ivy cover and clogging the intake port, allowing continuous and efficient aeration. Furthermore, by maintaining positive pressure at least in the vicinity of the intake port within the cover, the amount of intake air increases and more efficient aeration can be performed.

[Brief explanation of the drawing]

FIG. 1 is a cross-sectional view of the first embodiment of the present invention;
3 and 3 are cross-sectional views of a second embodiment of the present invention, and FIG. 4 is a cross-sectional view of a third embodiment. 1 is a motor, 2 is a hollow shaft, 3 is an intake port, 4 is a stirring blade, 5 is a cover, 6 is a fan, 7 is a fan cover, 8 is a partition plate, 9 is a seal, and 51 is an opening.

Claims (1)

[Claims] 1. A stirring blade 4 is attached to the underwater part of a hollow shaft 2 driven by a motor 1 installed above the water, and the negative pressure generated by the rotation of the stirring blade 4 is used to stir air into the water. In the aeration device, an air intake port 3 is provided above the water surface of the hollow shaft 2, the motor 1 and the air intake port 3 are covered with a cover 5 having an opening 51 at the upper part, and the air intake port 3 is located at a position below the air intake port 3. A seal 9 that closes the gap between the hollow shaft 2 and the cover 5
An aeration device characterized by being equipped with. 2. In an aeration device, a stirring blade 4 is attached to the underwater part of a hollow shaft 2 driven by a motor 1 installed above the water, and air is blown into the water using the negative pressure generated by the rotation of the stirring blade 4. An intake port 3 is provided above the water surface of the hollow shaft 2, and a cover 5 having an opening 51 at the top extends from above the motor 1 to the underwater part of the hollow shaft 2, and the air pressure inside the cover 5 is controlled. An aeration device characterized in that a fan 6 for increasing the aeration is attached to the motor 1.