KR100551983B1 - Air diffuser using bubble jet collision - Google Patents

Abstract

The present invention relates to a bubble jet impingement diffuser used in the aeration process of the sewage / wastewater treatment plant, and more specifically, by installing two or more so that the outlet of the nozzle body to face, the bubble jet coming from it collide with each other microbubble It relates to a bubble jet impingement diffuser device that can form a high oxygen transfer efficiency in water.

To this end, the present invention is an air dispersing device used for supplying air to the aeration process of the wastewater treatment plant, the air supply inlet is formed so that air is introduced into the air dispersing device, and connected to the air supply inlet from the air supply inlet A plurality of branch pipes formed to face each other while branching the introduced air, nozzle inclined slopes formed continuously in the branch pipes to increase the flow rate of the introduced air, and air continuously formed therefrom to increase the flow rate. It provides a bubble jet impingement type air dispersing device comprising a nozzle body is formed in the air outlet in the form of a nozzle neck spraying.

Air diffuser, bubble jet, collision angle, fine bubble, nozzle body, branch pipe, air outlet

Description

Air bubble jet collision diffuser {AIR DIFFUSER USING BUBBLE JET COLLISION}

1 is a cross-sectional view showing a general diffuser;

Figure 2a is a cross-sectional view showing an air diffuser using a conventional acoustic resonance;

Figure 2b is a plan sectional view showing a diffuser using a conventional acoustic resonance;

3 is a cross-sectional view showing a first embodiment and a second embodiment of a bubble jet collision type diffuser according to the present invention;

Figure 4 is an enlarged perspective view of the nozzle body of the bubble jet impingement diffuser according to the present invention;

5 is a cross-sectional view showing a third embodiment and a fourth embodiment of the bubble jet impingement diffuser according to the present invention;

6 is a cross-sectional view showing a guide groove formed in the nozzle shrinkage inclined surface constituting the bubble jet impingement diffuser according to the present invention;

7 is a plan view showing a state in which the nozzle body of the bubble jet collision type diffuser according to the present invention is disposed.

♣ Explanation of symbols for main part of drawing ♣

d1: chamber lower diameter d2: chamber upper diameter

d3: inlet diameter h: chamber height

Dn: Nozzle Spacing L1: Nozzle Neck Length

L2: nozzle neck length φ1: nozzle inlet diameter

φ2: nozzle inlet diameter φ3: nozzle neck diameter

φ4: nozzle neck diameter θ1: nozzle shrinkage angle

θ2: nozzle shrinkage angle θ3: nozzle body angle

θ4: nozzle body angle 1: chamber

2: entrance 3: exit

4: diffuser device 5: branch pipe

6: nozzle body 7: nozzle neck

8: air outlet 9: nozzle shrinkage slope

10: exit enlarged slope

The present invention relates to a bubble jet impingement diffuser used in the aeration process of the sewage / wastewater treatment plant, and more specifically, by installing two or more so that the outlet of the nozzle body to face, the bubble jet coming from it collide with each other microbubble It relates to a bubble jet impingement diffuser device that can form a high oxygen transfer efficiency in water.

A general conventional diffuser device is composed of a connector body 21, a fixing table 22, 24 and a pipe 23, as shown in FIG. In the conventional air diffuser, the air entering the connector body 21 passes through the fine holes 23a formed in the pipe 23 and is formed into small air bubbles and is supplied into the water. In this case, the pipe 23 has a separate hole. Rather than being present, when the pipe is made of ceramic or polyethylene (PE), the micro holes are produced in advance.

However, the conventional conventional diffuser is a device for reducing the size of air bubbles by simply passing the supplied air through the fine holes 23a, and there is a limit in reducing the size of air bubbles, in particular, the fine holes 23a. The micropores 23a are frequently clogged by impurity particles introduced or introduced into the air between the aquatic plants, and the amount of aeration is drastically reduced during use, so that the oxygen supply efficiency to the aeration device is lowered, and the micropores 23a are blocked. In order to solve the phenomenon, it is inconvenient to separate and frequently maintain the air diffuser.

In order to solve the problems of the conventional conventional diffuser, there is a "spreader using acoustic resonance" of the Republic of Korea Patent Registration No. 10-206746, which the inventors have applied for a patent.

In the air diffuser using the acoustic resonance, as shown in FIGS. 2A and 2B, the compressed air entering the inlet 2 provided in the tangential direction of the chamber 1 rotates inside the chamber 1 to vortex. And exit to exit (3). When the compressed air is discharged into the water through the outlet (3), a resonance occurs at a specific frequency due to the pressure difference between the compressed air and the water around the air diffuser, the acoustic energy is transferred to the water as a result of air bubbles It increases the dissolution rate of oxygen by increasing the mass transfer performance from

In addition, the conventional acoustic resonance diffuser is a semi-permanent diffuser that does not require the maintenance and cleaning of the diffuser because there is no fine hole (23a) formed in a typical diffuser does not cause clogging caused by long operation. .

However, the above-mentioned conventional acoustic resonance diffuser has a great problem that the oxygen transfer performance is low despite the advantage that clogging does not occur.

That is, the conventional acoustic resonance diffuser measured using the American Society of Civil Engineers' Regulation (ASCE 2-92) has a standard Oxygen Transfer Efficiency (SOTE) of 18% at 150 L / min of supply air flow. It shows less value than the diffuser or membrane diffuser. This is because in the conventional acoustic resonance diffuser, the splitting of the large air bubbles coming out of the outlet 3 is not activated, so that the bubbles have a short residence time and the contact area between the air bubbles and the water is small.

In order to solve the above problems of the prior art, the present invention is installed by two or more so as to face the nozzle body and the nozzle body formed with an enlarged air outlet, such that two bubble jets coming out from the air outlet collide with each other, the bubble breakage phenomenon To provide a bubble jet impingement type air dispersing device that can achieve high oxygen transfer efficiency by increasing the air bubble's underwater stay time by activating small bubbles to increase the underwater residence time of the air bubbles. There is this.

In order to achieve the above object, the present invention is an air dispersing apparatus used for supplying air to the aeration process of the wastewater treatment plant, the air supply inlet is formed so that air is introduced into the air dispersing apparatus, and is connected to the air supply inlet A plurality of branch pipes formed to face each other while branching the air introduced from the air supply inlet; a nozzle contracting slope formed continuously in the branch pipe to increase the flow rate of the introduced air; and continuously formed therefrom Provided is a bubble jet impingement diffuser comprising a nozzle body in which an air outlet in the form of a nozzle neck for injecting this increased air is formed.

In addition, the present invention is formed so that the plurality of branch pipes face each other in a horizontal state or mutually upward facing each other so that the bubble jets escaped from the air outlet, the air outlets are spaced apart from each other and the centerline of the bubble jets escaped therefrom Are formed to meet at one point.

In addition, the present invention is the diameter of the air outlet is enlarged by the exit enlarged inclined surface formed continuously from the nozzle neck, the nozzle shrinkage inclined surface and the nozzle enlarged inclined surface to form a spiral or radial guide grooves.

In addition, the present invention is such that the diameter of the air supply inlet is formed larger than the diameter of the nozzle neck and the diameter of the nozzle outlet, the shape of the nozzle neck to be one of the circular or elliptical and polygonal shape.

Hereinafter, with reference to the accompanying drawings will be described in detail the configuration of the present invention.

3 is a cross-sectional view showing a first embodiment and a second embodiment of a bubble jet collision type air diffuser according to the present invention, Figure 4 is an enlarged view of the nozzle body of the bubble jet collision type air diffuser according to the present invention. 5 is a cross-sectional view showing a third embodiment and a fourth embodiment of the bubble jet impingement diffuser according to the present invention.

The present invention has been applied to the specific embodiments as shown in each of the above drawings, the present invention is not limited to these specific embodiments, and various modifications can be made without departing from the spirit of the present invention.

As shown in (a) of FIG. 3 and (a) of FIG. 4, the bubble jet impingement diffuser according to the present invention is installed to face two air outlets 8 having nozzle necks 7. The basic concept is to give the jet of bubbles out of the device and induce a collision of the jets at the same time.

That is, the air supply inlet 4 is connected to a plurality of branch pipes 5 for branching the air supplied therefrom in the same amount, and the branch pipes 5 are air outlets 8 formed in the nozzle body 6. ) Are formed to face each other in a horizontal state (180 degrees) so that the bubbles escaped from the air outlet 8 collide with a collision angle of 180 degrees.

The internal space of the nozzle body 6 is formed with a nozzle shrinkage inclined surface 9 for increasing the moving speed of the air supplied from the branch pipes 5 having diameters φ1 and φ2, and the nozzle neck (7) ) And an air outlet 8 are formed.

The contraction angles Θ1 and Θ2 of the nozzle shrinkage inclined surface 9 may be any range as long as the diameter of the nozzle neck 7 may be smaller than the diameter of the branch pipe 5. However, when the shrinkage angles Θ1 and Θ2 are formed too rapidly, the nozzle shrinkage inclined surface 9 becomes long and the nozzle body 6 becomes unnecessarily large, and the shrinkage angles Θ1 and Θ2 are formed too large. Since some of the air supplied from the branch pipe 5 causes energy loss in the form of eddy, which is unnecessary secondary flow in the space between the nozzle neck 7 and the nozzle shrinkage inclined surface 9, the nozzle shrinkage inclined surface 9 The contraction angles of Θ1 and Θ2 are maintained at an appropriate level.

The air passing through the nozzle shrinkage inclined surface 9 formed as described above becomes the maximum speed when passing through the nozzle neck 7 having diameters φ3 and φ4 and lengths L1 and L2, and the air having such a high flow rate and low pressure. Bubbles exit the air outlet 8 and are supplied into the water.

On the other hand, the nozzle-type diffuser according to the present invention, as shown in Figure 3 (b) and Figure 4 (b), the angle of impact of the bubble jet exiting the air outlet (8) Instead of the above-described 180 degrees (horizontal state) facing each other, it is possible to achieve a collision angle facing upward at a predetermined angle (θ3, θ4).

That is, the air supply inlet 4 is not formed such that a plurality of branch pipes 5 for branching the air supplied therefrom in the same amount are faced in a horizontal state (180 degrees), but rather have predetermined upward angles θ3 and θ4. Bubble jets exiting from the air outlet 8 of the nozzle body 6 formed in the respective branch pipes 5 are formed at a predetermined angle (θ3, θ4) rather than a collision angle of 180 degrees (horizontal state). It collides with the collision angle facing upwards to make it differentiate into microbubbles.

In addition, in the bubble jet impingement diffuser according to the present invention, as shown in FIG. 5, the air outlet 8 may be larger than the diameter of the nozzle neck 7.

That is, the diameter φ 5 of the air outlet 8 is enlarged by the outlet enlarged inclined surface 9 which is formed continuously in the nozzle neck 7 described above, and the diameter of the outlet enlarged inclined surface 9 is the nozzle. It is because it is formed larger than the neck (7) can reduce the load on the device body (4) by the high pressure air in accordance with the air conditioner operating conditions. At this time, the angle is preferably formed to be the same as the angle of the nozzle shrinkage inclined surface (6).

The high-speed air bubbles exiting the plurality of air outlets 8 of the bubble jet impingement diffuser of the present invention, respectively formed as described above, are in contact with water around the diffuser having a low flow rate, and at the interface between the water and the bubble Shear stress due to the large speed difference is generated, and the splitting of air bubbles is activated.The activated bubble jets collide with each other at a predetermined angle to differentiate into small micro bubbles, and the small size micro bubbles have a long underwater residence time. The water-bubble contact area is large, which increases oxygen transfer performance.

When the bubble jet collision type air diffuser according to the present invention is applied in wastewater treatment or the like, it can be used in conjunction with an air or oxygen supply device, so that an appropriate fastening means can be formed. As the fastening means, various conventionally known methods such as bolting fastening or quick joint fastening can be employed, and various materials such as metal, ceramic, and plastic may be used as the material of the bubble jet impingement diffuser according to the present invention.

Referring to the operation of the bubble jet collision type diffuser according to the present invention.

First, the compressed air supplied to the air supply inlet 4 of the bubble jet impingement diffuser according to the present invention flows along a plurality of branch pipes 5 continuously connected to the plurality of nozzle bodies 6.

The air that flows along the branch pipe 5 to the nozzle body 6 flows along the nozzle shrinkage inclined surface 9 and becomes a maximum speed through the nozzle neck 7. The air bubbles having such a high velocity flow out of the air outlet 8 of the air diffuser to be fed into the water to form a bubble jet.

The bubble jet is in contact with the water around the air flow device with a low flow rate, the shear stress caused by a large speed difference is generated at the interface between the water and the bubble is activated the splitting of the air bubbles from the bubble jet collision type of the present invention The oxygen transfer performance of the diffuser is increased.

In addition, since the bubble jet is formed from a plurality of air outlets 8 facing each other at regular intervals, the bubble jets collide with each other to activate the bubble splitting due to a large flow rate difference (large shear stress), thereby providing fine bubbles. The micro-bubbles are to stay in the water for a long time to supply oxygen more efficiently into the water.

In general, Standard Oxygen Transfer Efficiency (SOTE) at a water temperature of 20 ℃ representing the performance of the diffuser is represented by the following equation (1).

In order to understand the standard oxygen transfer efficiency, it is necessary to examine the oxygen movement from the gas phase to the liquid phase. Equation 2 for the oxygen transfer rate (dW / dt) is mainly used.

In Equation 2, it can be seen that the moving speed of oxygen (dW / dt) in water is proportional to the gas-liquid contact area (a) and the oxygen transfer coefficient (k _L ) of the gas-liquid interface. The contact area (gas-liquid contact area; a) of gas and water increases as the size of the bubble becomes smaller in water, for the same amount of gas. In addition, the oxygen transfer coefficient (k _L ) of the gas-liquid interface is inversely proportional to the thickness of the interface between the bubbles and water, and the oxygen transfer coefficient (k _L ) is more stable than the static state due to vortices or turbulent flows. It is known to decrease and increase.

Taken together, in order to increase the standard oxygen transfer efficiency, first, microbubbles are generated in order to increase the contact area of water and air, and the path of movement of the bubbles in order to increase the contact time with water is possible. It is horizontal to extend the residence time in water.

The present invention considers both of the above methods and is designed to improve the low oxygen transfer performance of the conventional acoustic resonance diffuser.

6 is a cross-sectional view showing a guide groove formed in the nozzle contraction inclined surface constituting the bubble jet collision type diffuser according to the present invention, Figure 7 is a state in which the nozzle body of the bubble jet collision type diffuser according to the present invention is disposed It is a top view shown.

Meanwhile, in the present invention, as shown in FIG. 6, the guide groove 12 may be formed in the nozzle contraction inclined surface 6 and the outlet enlarged inclined surface 10. The guide groove 12 is supplied so as to reliably guide the air having a higher speed and a lower pressure by the nozzle contraction slope 6 to the nozzle neck 6 and the air outlet 8 or to improve turbulence strength. Will be.

That is, a spiral groove 12a or a radial groove 12b guide groove 12 may be formed in the nozzle contraction inclined surface 6 and the nozzle enlarged inclined surface 10 of the diffuser of the present invention. It serves to increase the turbulence intensity of the air speeds up along the nozzle shrinkage slope 6, and in the case of the guide groove 12 of the radial (12b) serves to improve the direction of the supplied air. .

In addition, the bubble jet impingement diffuser according to the present invention, as shown in Figure 7, can be formed so that a pair of nozzle body 6 to face each other, three nozzle body 6 is the same installation It may be formed at an angle (120 degrees), and two pairs of nozzle bodies 6 may be installed at an angle of 90 degrees. Therefore, the bubble jets generated from the plurality of nozzle bodies 6 collide with each other to differentiate into finer bubbles.

In addition, the shape of the nozzle neck 7 formed in the present invention may be installed in the form of circular and polygon as well as circular. That is, the shape of the nozzle neck 7 may be determined in consideration of the shape and size of the aeration device to which the bubble jet impingement diffuser is applied, and the amount of air required, and each air outlet 8 may have a different size. have.

The nozzle type diffuser according to the present invention is applicable to supplying a gas such as oxygen to a liquid in beer fermentation process, microbial fermentation process, other wastewater treatment process, or other chemical process, in addition to oxygen supply of wastewater treatment plant. It can also be used to mix two types of materials, such as liquids and solids, or liquids and liquids.

As described above, the present invention by installing a nozzle neck at the two air bubble air outlets facing each other at a constant interval to make the air exiting the air outlet of the air dispersing device is a bubble jet having a large momentum, bubbles facing each other The jet impinges on and activates the splitting of bubbles due to the large flow rate difference (large shear stress). The shear stress of water and bubble boundary is one of the biggest factors affecting the splitting of bubbles. The increase of the shear stress at the gas-liquid interface means that the pressure of gas inside the bubble and the surface tension of the gas-liquid interface determine the size of the bubble. This means that the bubble is broken, which causes large bubbles to break down into smaller bubbles to reach a new equilibrium, and the differentiated bubbles are more efficient in supplying oxygen into the water while staying in water for a long time. . That is, in the case of the conventional diffuser using acoustic resonance, it was found that there is about 18% of standard oxygen transfer efficiency (SOTE), but the nozzle type diffuser of the present invention has a standard oxygen transfer efficiency (SOTE) of about 20 to 30%. Significantly improved.

The bubble jet collision type air diffuser according to the present invention has a simple structure and does not require maintenance and cleaning in use, and is small in size and economical in initial purchase cost. In addition, depending on the conditions of use, the diffuser outlet can be installed horizontally or downwards, as well as upward installation, which is a common installation method.

Claims (7)

In the diffuser device used for supplying air to the aeration process of the wastewater treatment plant, An air supply inlet formed to allow air to flow into the diffuser; A plurality of branch pipes connected to the air supply inlet and formed to face each other while branching air introduced from the air supply inlet; And a nozzle body having a nozzle contracting inclined surface continuously formed in the branch pipe to increase the flow velocity of the introduced air, and an air outlet in the form of a nozzle neck that is continuously formed therein and sprays the air with increased flow rate. Bubble jet collision type diffuser characterized in that. The method of claim 1, wherein the plurality of branch pipes are bubble jet collision type diffuser device, characterized in that formed to face each other in a horizontal state or upward facing each other so that the bubble jets escape from the air outlet. The method of claim 2, wherein the air outlet is a bubble jet collision type diffuser, characterized in that the center line of the bubble jet is separated from each other and formed to meet at one point. The bubble jet impingement diffuser of claim 3, wherein the air outlet is enlarged in diameter by an outlet enlarged inclined surface continuously formed from the nozzle neck. The bubble jet impingement diffuser according to any one of claims 1 to 4, wherein the nozzle contracting inclined surface and the nozzle expanding inclined surface are formed with a helical or radial guide groove. The bubble jet impingement diffuser according to any one of claims 1 to 4, wherein the diameter of the air supply inlet is larger than the diameter of the nozzle neck and the diameter of the nozzle outlet. The method of claim 1, wherein the nozzle neck is bubble jet collision type diffuser, characterized in that one of the shape of a circle or oval and polygon.

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