JPS59206096A - Aerating apparatus - Google Patents

Abstract

PURPOSE:To improve efficiency for treating filthy water by utilizing generated fine bubbles by providing a gas supplier and a liquid supplier both confronting the inlet of a stationary mixer and having an ejection port of gas and an ejection port of liquid respectively opening toward an axial direction of the stationary mixer for generating fine bubbles. CONSTITUTION:In an aerating appatatus, a gas supplier 2 ejects gas and generates bubbles, on one hand, a liquid supplier 3 ejects liquid. Filthy water 5 is sucked into a mixer 1 by the air-lifting effect of the bubbles. The filthy water 5 and the liquid ejected from the liquid supplier 3 rise upward through the inside of the mixer 1 while repeating collision with each other. During this stage, the bubbles are broken, therefore, fine bubbles are blown into the filthy water 5 from the outlet (upper end of the mixer). In the stationary mixer 1, plural numbers of twisted blades are arranged in a tubular passage 6 of fluid having an inlet and outlet of the fluid wherein the edges of the twisted blades cross with each other at a desired angle.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an aeration device, and more particularly to an aeration device used in treating sewage.

For example, in equipment that mainly uses aerobic microorganisms to treat wastewater, such as activated sludge water treatment equipment and contact oxidation water treatment equipment, in order to improve treatment efficiency, an aeration device is immersed in the wastewater to generate air. is blown into the wastewater to dissolve oxygen and promote the growth of microorganisms, while also making the wastewater flow and promoting efficient contact with microorganisms.

Conventionally, the aeration equipment used in such cases is a diffuser pipe with many fine discharge holes, or a diffuser pipe with quite thin discharge holes. There is a known type of air diffuser which consists of a diffuser tube and a diffuser plate having a large number of fine diffuser holes, which is provided so as to cover the lower side of the diffuser tube. However, these conventional devices generate fine bubbles in wastewater by minimizing the pore diameter of the discharge hole or aeration hole, thereby increasing oxygen dissolution efficiency and thereby improving treatment efficiency. That is. However, since such conventional aeration devices have a structure having fine discharge holes and diffuser holes, there is a drawback that these holes are easily clogged by pollutants in the waste water and dust in the air. This problem of so-called clogging could be solved by increasing the pore diameter, but then the bubble diameter would become larger and the oxygen dissolution efficiency would decrease, making it impossible to achieve high treatment efficiency.

On the other hand, in recent years, a so-called static mixer is used, in which a plurality of twisted blades are arranged in a row in a fluid passage having a fluid inlet and an outlet, and an air nozzle is installed opposite the inlet of the mixer. An aeration device that is installed has also been proposed. This aeration device uses the air lift effect when air bubbles move inside the mixer to suck surrounding wastewater into the mixer, and uses the collision energy of the wastewater to crush and reduce the size of the air bubbles. be. Therefore, the hole diameter of the air nozzle may be large, and there is almost no fear of clogging as described above. Also, pressure loss is low. However, since this device only has an air nozzle, in other words, only air is discharged, a sufficient air lift effect cannot be obtained unless the discharge amount is quite large, and the size of the mixer If it is not large, the Reynolds number will be small and the flow of sewage in the mixer will become laminar, which has the disadvantage that the bubble crushing effect will be low in either case. That is,
The above-mentioned conventional devices are only effective when the air discharge amount and mixer dimensions are above a certain level.

The purpose of the present invention is to solve the above-mentioned drawbacks of conventional aeration equipment,
To provide an aeration device that can generate fine air bubbles regardless of the size of the air supply (a) or the mixer, and can achieve high sewage treatment efficiency.

To achieve the above object, the present invention provides a static mixer comprising a plurality of torsion blades arranged in a row within a fluid passage having a fluid inlet and an outlet. This is characterized by an aeration device in which a gas supply device and a liquid supply device are arranged side by side, each having a discharge port opening in the axial direction connecting to the outlet.

To explain the present invention in detail, FIG. 1 (schematic front view with cross-sectional view) shows an lσ aeration device according to an embodiment M of the present invention installed at the bottom of an aeration tank 4 containing wastewater 5. This indicates the state in which the .

The aeration device includes a static 1L type mixer 1 installed vertically in the aeration tank 4, and a lower end of the mixer 1, that is, facing the fluid inlet.
It has a gas supply device 2 and a liquid supply device 3, each having a discharge port opening in the axial direction connecting the inlet and the upper end of the mixer 1, that is, the fluid mouth. The gas supply device 2 is connected to a supply source (not shown) of an aerobic gas such as air or an anaerobic gas such as nitrogen gas, and the liquid supply device 3 is connected to a source of clean water (not shown). It is connected to the. It may also be connected to the circulation system of the waste water 5 or to a source such as raw water so that a portion of the waste water 5 can be extracted and supplied. .

The aeration device generates air bubbles by discharging gas from the gas supply device 2, while discharging liquid from the liquid supply device 3, thereby producing air bubbles and sewage 5 and sewage sucked into the mixer 1 by the so-called air lift effect. The liquid discharged from the liquid supply device 3 rises in the mixer 1 while repeatedly colliding with the liquid, during which air bubbles are crushed and fine air bubbles can be blown into the waste water 5 from the fluid outlet.

In the above, the static mixer is shown in Fig. 2 (schematic perspective view).
As shown in FIG. 2, a plurality of twisted wings 7 are arranged in a row in a tubular fluid passage 6 having a fluid inlet and an outlet so that their edges intersect with each other at a desired angle. It does not have any moving parts such as stirring blades. However, the present invention is not limited to what is shown in FIG. 2, but is also applicable to, for example, Japanese Patent Publication No. Shozz-829o, Japanese Patent Publication No. 53-36182, and U.S. Patent No. 3,404. ．． 8698'', Mei 1ift, etc. Other static mixers may also be used.In addition, in the mixer shown in FIG. The edge may be in contact with the adjacent twist or may be separate.

The gas supply device is a nozzle or a diffuser pipe as described above. However, when using an aeration pipe, the diameter of the discharge hole does not need to be as fine as in conventional aeration equipment. Such a gas supply device may be installed so that its discharge port is on the same plane as the entrance of the fluid into the mixer, or it may be installed so that it is inside the mixer. Also,
As long as most of the bubbles generated by this gas supply device are introduced into the mixer, it is acceptable to install it outside the mixer. In short, it may be installed opposite the fluid inlet of the mixer. Note that the number of gas supply devices does not need to be just one, and a plurality of gas supply devices may be installed in parallel.

A nozzle is usually used as a liquid supplier. The discharge port of this liquid supply device is similar to that of the above gas supply device,
It may be flush with the fluid inlet of the mixer, within or outside the mixer. However, if it is installed outside the mixer, the bubble crushing effect will be reduced if the speed of the discharged liquid is significantly slowed down by surrounding waste water, so make sure it is not too far away from the fluid inlet of the mixer. is preferable. Further, the discharge port of the liquid supply device is preferably located on the fluid inlet side of the mixer rather than the gas supply device so that the discharged liquid is not obstructed by the gas supply device and loses kinetic energy. Note that a plurality of liquid supply devices may be installed similarly to the gas supply device described above.

The liquid discharge speed by the liquid supply device is set higher than the moving speed of bubbles generated by the gas supply device. Furthermore, the effect of crushing bubbles increases in proportion to the amount of liquid discharged up to a certain extent. However, when considering the power energy required for ejection, it is not a good idea to increase the pressure unnecessarily. Therefore, the amount of liquid discharged is usually set to about 1/20 to 1 times that of gas. Preferably, it is 1/10 to 1 times.

In the above embodiment, the static mixer is installed vertically, but it may also be installed horizontally or diagonally.

The aeration device of the present invention can be used in various types of water treatment devices depending on the type of gas discharged from the gas supply device. That is, by discharging air, the device can be used as an aeration device for devices that mainly utilize aerobic microorganisms to treat wastewater, such as activated sludge water treatment devices and catalytic oxidation water treatment devices. In addition, anaerobic gas such as nitrogen gas
If one gas is discharged, it can be applied to water treatment equipment for purposes such as denitrification. Furthermore, the aeration device of the present invention includes:
Not only can it be used by installing it in water treatment equipment, but it can also be used to purify water by immersing it in lakes, rivers, etc.

As explained above, since the aeration device of the present invention has the gas supply device and the liquid supply device arranged side by side facing the fluid inlet of the static mixer, the air bubbles moving inside the mixer are The waste water sucked in from the surrounding area by the air lift effect during its movement and the liquid discharged from the liquid supply device and forced into the mixer are combined to crush the waste into fine pieces. Therefore, gas dissolution efficiency is greatly improved, and wastewater treatment efficiency is improved. Moreover, the pore size of the bubbles generated by the gas supply device can be large, so that
Since there is no need for an air diffuser to generate fine air bubbles, there is no need to worry about clogging. In addition, unlike conventional aeration equipment, the air bubbles are broken only by the sewage sucked in by the air lift effect, but because the action of the liquid discharged from the liquid supply device is also used, the amount of gas discharged is small. Even in such cases, a sufficiently large crushing effect can be achieved and the dissolution efficiency is improved. Furthermore, in conventional aeration equipment, when the size of the mixer is small, it is difficult to generate turbulent flow inside the mixer, which reduces the effectiveness of breaking bubbles. The aeration device of the invention eliminates such concerns because the liquid supply devices are arranged in parallel, and the liquid can be forced to flow into the mixer to create a turbulent flow state.

[Brief explanation of the drawing]

FIG. 1 is a schematic front view including a sectional view showing an aeration device according to an embodiment of the present invention installed in an aeration tank, and FIG. 2 is a schematic front view of a static mixer used in the present invention. It is a schematic perspective view showing an example. 1: Static mixer 2: Gas supply device 3; Liquid supply device/I: 1σ gas tank 5: Sewage 6: Fluid passage 7: Twisted blade special [Applicant Toshi Co., Ltd. 1 10- Figure 1 Figure 2

Claims (1)

[Claims] A discharge port opening in the axial direction connecting the inlet and outlet, facing the inlet of a static mixer comprising a plurality of twisted blades arranged in a row in a fluid passage having a fluid inlet and outlet. An aeration system consisting of a gas supply device and a liquid supply device arranged in parallel.