JP2820295B2 - Diffuser - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to an air diffuser, and more particularly to an apparatus for treating organic substances contained in wastewater by the biological action of aerobic microorganisms, such as an activated sludge treatment tank. The present invention relates to an air diffuser particularly suitably used for an aerobic biological treatment apparatus.

(Prior Art) A conventional example of an air diffuser of the present invention will be described for an activated sludge treatment apparatus to which the air diffuser is suitably applied.

Generally, in an activated sludge treatment apparatus using an aerobic microorganism, aeration is usually performed from below the inside of a treatment tank (this treatment tank is sometimes referred to as an “aeration tank”). The purpose of this aeration is, in part, to promote the mixing of the treatment liquid and the activated sludge, but the main purpose is to increase the concentration of dissolved oxygen in the treatment liquid, thereby reducing the optimal environment for aerobic microorganisms. Feeding and supplying oxygen to the treatment liquid is one of the indispensable operations in activated sludge treatment equipment in order to advance biological reactions such as organic matter oxidation by microorganisms, proliferation of microorganisms, and auto-oxidation by dissolving oxygen in the treatment liquid. is there.

As described above, in the aerobic microorganism treatment tank, the appropriateness of the aeration greatly affects the treatment efficiency. Conventionally, in order to appropriately realize the aeration, the aeration is performed based on how efficiently oxygen is dissolved in the treatment solution. Tanks and aeration devices are often designed.

Conventionally known as such an aeration device are a mechanical stirring type and a type using a combination of aeration and mechanical agitation, but typically, the aeration type device targeted by the present invention is easy to maintain and manage. It is widely used practically because of its excellent economy.

FIG. 6 shows an example of an aerobic microorganism treatment apparatus using a conventional aeration type aeration apparatus (hereinafter referred to as "aeration apparatus"). In this figure, each aeration tank (third structure) is shown.
An air diffuser 51 is arranged at the bottom of 50. The air diffuser 51 is provided with an air supply pipe 52 extending vertically downward from the upper part of the tank.
A trunk pipe 53 extending horizontally on both sides is connected to the lower end of the pipe, and a large number of branch pipes 54 are extended from this trunk pipe 53 on both sides in the horizontal direction, and a porous diffuser pipe 55 such as an unglazed pipe is connected to the tip thereof. Is configured as And from the air supply pipe 52,
The air supplied to the air diffuser 55 through the main pipe 53 → the branch pipe 54 is diffused from a large number of fine holes of the air diffuser, thereby blowing bubbles into the processing liquid, and mixing and stirring the processing liquid. It is designed to supply oxygen. In addition, such a diffuser is arranged such that it is unevenly disposed on one side of the aeration tank 50 as shown in FIG. 6 (b) so that the processing liquid is swirled while stirring and mixing the processing liquid by a swirling flow. What is usually.

In addition to the diffuser using the tubular diffuser, the upper part of the open-top box-type closed container is closed with a ceramic plate or the like having pores, and a porous hole is formed by a method of diffusing air through the ceramic plate. Also known are a diffuser plate, a bag-shaped diffuser tube, a Saran-wrapped diffuser tube, a sparger, and a disk fuser.

However, such a conventional air diffuser has the following problems. That is, for the purpose of efficiently dissolving oxygen in the processing liquid, it is preferable to increase the contact area between the air and the liquid as much as possible, and for this purpose, it is desired to minimize the air bubbles to be diffused. . For this reason, as the above-mentioned air diffuser or ceramic plate, those having fine pores are often used so that air bubbles having a diameter as small as possible can be generated. In particular, recently, an air diffuser having a micropore of about 200 μm, which can generate ultrafine bubbles having an average diameter of about 2 mm, is also used as an actual apparatus.

However, with such a configuration, the air diffuser is likely to cause clogging in the air diffuser and the like, and as a countermeasure, remove dust, dust, rust, oil, etc. from the supplied air with an air purifier. There is a problem that the burden increases in terms of equipment. In addition, as a problem of clogging from the outside of the diffuser tube, sludge, sand, oil, garbage iron bacteria and the like in the tank adhere to the surface and block the pores, which causes a reduction in the life of the diffuser tube. .

For the diffuser tubes and the like whose clogging has occurred and the diffusing efficiency has been reduced, baking treatment, acid treatment, surface polishing, etc. are performed depending on the material of the apparatus and the type of clogged ones. If clogging has progressed to some extent, replacement will be required. However, the replacement work is not easy, and a large number of replacements are required. Therefore, there is a problem that the cost and time required for the replacement work are increased.

(Problems to be Solved by the Invention) The present invention realizes efficient dissolution of oxygen in a liquid, which has been a problem in the conventional air diffuser as described above, and a technique for such efficient dissolution. It is an object of the present invention to provide a novel air diffuser which can simultaneously solve the problem of clogging of an air diffuser tube due to miniaturization of air bubbles required for the above purpose.

Another object of the present invention is to provide an air diffuser which has a simple structure and has a small facility load, and which can perform an assembling operation and an exchanging operation extremely simply and in a short time. .

Still another object of the present invention is to provide an air diffuser with low maintenance and management costs, because the replacement member when the air diffusion efficiency is reduced can be limited to a part of the device.

(Means for Solving the Problems) The feature of the air diffuser of the present invention that achieves the above-described object is that the air diffuser is disposed in an aeration tank and does not have a function of itself forming fine bubbles, but has a large air volume. An air ejection means having an ejection port, and a large number of synthetic resin hollow cylinders covering an upper portion of an air ejection portion of the air ejection means over a wide area and having a mesh-like cylindrical shell are substantially horizontally closely contacted and aligned. The stacking section block is composed of stacking sections stacked in multiple stages, and the stacking state of the hollow cylindrical body of the stacking section block is such that the cylinders are turned at right angles at every single step or every several steps. Where they are.

The air ejection means having the air ejection opening is not particularly limited, but generally, a tube having a large opening for ejecting air can be used.

As the cylindrical body having the above structure, for example, a cylindrical net made of a synthetic resin having a cylindrical shell having various mesh structures is suitably used as described in Examples to be described later, and a cylindrical type is particularly preferably used. Can be

Such an integrated block configured as a large number of cylindrical integrated bodies has a structure in which a large number of cylindrical bodies are stacked by changing the direction of the cylindrical body at a right angle at every stage or every several stages. Are representatively exemplified. The number of stacking layers is not particularly limited, and the number of layers suitable for subdividing bubbles can be appropriately set according to the size and shape of the cylindrical body. Further, particularly, a cylindrical module is formed in advance by storing a large number of cylindrical bodies in a basket, and the cylindrical module is detachably fixed to a mounting portion set on the upper portion of the air blowing means to constitute an integrated block. The type is exemplified as a suitable structure which is easy to assemble and replace the device.

(Function) The present invention has the above-described structure, and the device portion for supplying air from outside to the inside of the tank and the device portion for forming air bubbles supplied from the outside into the tank are independent of each other. Thus, the opening of the air ejecting means, which is the device for supplying air, can be made to have a size substantially free from the problem of clogging (for example, an opening of 3 mm or more). On the other hand,
The device portion for finely dividing the air supplied and discharged into the tank into fine bubbles can employ a configuration effective for forming the necessary small-diameter bubbles irrespective of the air jetting means.

(Examples) Hereinafter, the present invention will be described based on examples shown in the drawings.

FIG. 1 to FIG. 3 are diagrams showing an outline of the configuration of an embodiment of an aeration tank to which the air diffuser according to the present invention is applied.

In these figures, reference numeral 1 denotes an aeration tank (three tank structure), and a diffuser 2 is disposed at the bottom thereof. The configurations of the air diffusers 2, 2, 2 in these aeration tanks 1, 1, 1 in this example are the same.

The air diffuser 2 in this example includes an air supply pipe 3 extending vertically downward from the tank upper part, and a lower end of the air supply pipe 3.
Main pipe 4 fixedly connected to extend on both sides in the horizontal direction
And a branch pipe 5 extending to both sides in the horizontal direction from the main pipe 4 and having an extended end bent upward and open to provide air ejection means. Is provided by providing an integrated block body, which will be described later, so as to cover the upper part over a wide range in the vicinity of.

The air supply pipe 3 and the main pipe 4 may be the same as those in the above-described conventional example, but the branch pipe 5 is not provided with a function of forming fine bubbles itself, unlike a conventional diffuser pipe. A tube is fine. Therefore, this branch pipe 5 has, for example, an opening diameter.
A general nozzle type having a large air outlet such as 3 mm or more can be used.

By using an air ejection pipe having such a large-diameter opening, there is an advantage that the risk of clogging is substantially eliminated. That is, for example, when the operation of the aeration apparatus is stopped, the liquid and sludge may flow back into the pipe from the opening, but when the restart, the air for aeration can easily discharge the sludge in the pipe, so this opening is closed. Never.

Next, an accumulation block 10 constituted by accumulating a large number of cylinders
Will be described.

The integrated block 10 is preferably made of a synthetic resin cylindrical body 6 having various mesh-type cylindrical shells exemplified in FIG.
As shown in FIG. 5, a large number of these are arranged in a plane and densely arranged in multiple layers.

The cylindrical body 6 is preferably of a cylindrical type, which has the characteristic that rising bubbles can be subdivided even when the mesh is relatively large. Therefore, for such bubble subdivision, it is preferable that the density of the meshes of a multiplicity of cylindrical bodies stacked in multiple stages is given by averaging in the vertical direction as much as possible. It is preferable to stack a large number of cylinders in multiple stages so that the projected image of the mesh at the time is averaged as a whole. For this purpose, it is often preferable to stack the layers at right angles as shown in FIG. 5 (a) or (b).

The diameter of the tubular body and the shape of the mesh of the tubular shell are not particularly limited, and can be appropriately designed and determined depending on the desired degree of subdivision of the air bubbles, the scale of the tank, and the like. Preferably have a diameter of 50 to 200 mm and an opening diameter of the mesh of the cylindrical shell of about 5 to 15 mm.

In the process in which the air ejected from the air ejecting means passes through the accumulation block 10 composed of the cylinder 6 having such a mesh-like tubular shell, the air is gradually stirred into fine bubbles while being sufficiently stirred with the mixed solution. Distributed and subdivided.

Further, the material of the cylindrical body is not particularly limited for the purpose of dividing the air bubbles, but it is often preferable to use a synthetic resin material from the viewpoint of corrosion resistance, durability, cost and the like. When a synthetic resin cylinder having a low specific gravity is used, it is necessary to prevent the cylinder from floating in the processing liquid. For this reason, a large number of cylinders are accumulated and stored in an appropriate basket or the like. Then, it is preferable to adopt a configuration in which a cylindrical module is formed and the cylindrical module is fixed at a predetermined position in the aeration tank 1.

FIG. 2 and FIG. 3 show an example in which a basket 7 is used as a storage case for forming such a cylindrical module, and an integrated block is formed by the cylindrical module in which a cylindrical body is stored in the basket 7. It is shown. That is, a columnar structure 8 made of an angle or the like shown in FIG. 2 is provided at a predetermined position above the air jetting means of the aeration tank 1, and a cylindrical body is placed in the internal space formed by the columnar structure 8 in FIG. As shown in the figure, a basket 7 stored in a multi-layered structure is assembled and fixed by fixing means (not shown) to form an integrated block.

According to such a configuration, a cylindrical module in which a large number of cylindrical bodies are stacked and stored in multiple stages is assembled in a factory or a site in advance, and this is put into an aeration tank and fixed at a predetermined position, whereby a diffuser device is provided. It has the advantage that it can be formed and its workability is significantly simpler than before.

It is needless to say that the present invention is not limited to those described in the above embodiments, but can be carried out in an appropriately modified form.

(Effect of the Invention) As described above, the air diffuser of the present invention simultaneously solves two problems that could not be realized by the conventional air diffuser, that is, efficiently dissolves oxygen in a liquid, and There is an effect that the elimination of the clogging of the air diffuser and the like due to the miniaturization of the bubbles required for the efficient dissolution can be solved at the same time.

In addition, the air diffuser of the present invention has the effect that the structure is simple and the facility load is small, and the assembling and replacement work can be performed extremely easily and in a short time. Since the replacement member can be limited to a part of the apparatus (for example, replacement of an integrated block), there is an effect that the cost for maintenance can be extremely reduced. In addition, by adopting a system in which a plurality of cylindrical bodies are housed in a basket or the like as a cylindrical body module and an integrated block is formed using the cylindrical body module, the workability can be further simplified and speeded up.

Although the air diffuser of the present invention is particularly suitable for an aerobic biological treatment apparatus such as the activated sludge treatment apparatus described above, it goes without saying that it can also be used as an air diffuser for other uses.

[Brief description of the drawings]

1 (a), 1 (b) and 1 (c) are views showing an example of a configuration of a diffuser according to the present invention applied to an aeration tank, and FIG. 1 (a) is a longitudinal sectional front view thereof. FIG. 1 (b) is a vertical sectional side view, and FIG. 1 (c) is a plan view. FIG. 2 is a perspective view showing an outline of an integrated block body of the air diffuser in the embodiment, and FIG. 3 is a perspective view showing a state in which a large number of cylindrical bodies are housed in a basket. FIGS. 4 (a) to 4 (d) are perspective views exemplifying the detailed shapes of various cylinders, and FIGS. 5 (a) and 5 (b) exemplify typical examples of an integrated state. FIG. 6 (a), 6 (b) and 6 (c) are views showing an example of the configuration of a conventional diffuser applied to an aeration tank, and FIG. 6 (a) is a longitudinal sectional front view thereof. FIG. 6 (b) is a vertical sectional side view, and FIG. 6 (c) is a plan view. 1: Aeration tank, 2: Aeration device 3: Air supply pipe, 4: Main pipe 5: Branch pipe, 6: Cylindrical 7: Basket, 8: Column structure 10: Stacking block 50: Aeration tank, 51: Diffusion Pneumatic device 52: Air supply pipe, 53: Main pipe 54: Branch pipe, 55: Unglazed pipe

Claims (2)

(57) [Claims] 1. An air ejection means which is disposed in an aeration tank and has no function of forming fine bubbles per se but has a large air ejection port, and an upper portion of an air ejection portion of the air ejection means is provided over a wide area. An integrated unit block in which a large number of synthetic resin hollow cylindrical bodies having a covering and a mesh-shaped cylindrical shell are substantially horizontally closely contacted and aligned to form a planar shape, and are stacked in multiple stages. The air diffuser is characterized in that the multi-layered state of the hollow cylindrical bodies of the blocks is such that the cylindrical bodies are stacked at right angles at every one or several stages. 2. The air diffuser according to claim 1, wherein the accumulation block is configured by detachably fixing a basket containing a large number of cylindrical bodies to a mounting portion above the air jetting means. .