WO2000078466A1

WO2000078466A1 - High-efficiency gas dissolving device

Info

Publication number: WO2000078466A1
Application number: PCT/JP2000/004013
Authority: WO
Inventors: Hiromi Yamamoto; Kenji Taguchi
Original assignee: Fukuoka Prefectural Government; Riken Company Limited
Priority date: 1999-06-21
Filing date: 2000-06-20
Publication date: 2000-12-28
Also published as: JP2001000890A

Abstract

A high-efficiency gas dissolving device (10) which has a diameter-expanded nozzle with a collision member, wherein the shearing force and cavitation of water produced in the inner space of the diameter-expanded nozzle are utilized to efficiently atomize air, etc. This device (10) comprises a nozzle main body (11) having a water introducer (14), a gas feeder (16) and a diameter-expanded nozzle (17), and a collision plate (18) fixed to the nozzle main body. The water introducer (14) discharges high-pressure water, introduced through a water feeding port (12), from a discharge port (13). The gas feeder (16) is provided with a gas introducing port (15) in the water introducer (14) and mixes gas into the high-pressure water by ejector action. The diameter-expanded nozzle (17) positively generates cavitation in the inner space with a forwardly expanded diameter by the flow of high-pressure water discharged from the discharge port (13). The collision plate (18) is disposed with a gap defined in front of the diameter-expanded nozzle (17), so that the water mixed with fine air bubbles discharged from the diameter-expanded nozzle (17) is dispersed around.

Description

Akira Itoda High efficiency gas melting equipment

Technical field

The present invention relates to a high-efficiency gas dissolving apparatus, and more particularly, to a gas dissolving apparatus capable of extremely efficiently reducing the size of a gas by destructively miniaturizing the gas by using the shear force and cavitation of water. This gas dissolving apparatus is suitable for efficiently increasing the amount of dissolved oxygen in water near the bottom soil where organic matter such as bait and excrement accumulates, as in a culture pond, or for the treatment of wastewater in industry and the like. Background art

In recent years, for example, in aquaculture ponds, a large amount of fish and shellfish have been bred in a narrow space in order to increase the breeding efficiency, and their overdensity is increasing. As a result, the dissolved oxygen concentration (oxygen concentration in water) has decreased and the growth rate has slowed. In addition, residual food and excrement are deposited as organic matter on the bottom soil, causing mass mortality due to infection with pathogenic bacteria such as Vibrio bacteria and PAV virus generated in the sediment, causing a phenomenon that production efficiency is rapidly reduced. In particular, only about 20% of fish feed and other mixed feeds (400,000 tons of domestic use) are consumed by fish and shellfish, and the remaining 80% is deposited on bottom soil. In addition, chemicals such as antibiotics and growth hormones for growth promotion and evolution are used in the diet as a measure against pathogenic bacteria. However, it is only effective if the bred fish and shellfish have sufficient resistance (immunity). In a state of lack of oxygen, the resistance is weak and the effect has not increased. For this reason, to remove and purify sediments, it is necessary to purify A chemical action is required. Therefore, sufficient oxygen is essential for microbial activity.

Recently, from a pathological standpoint, research and development of viral bacterial agents called biopesticides have been promoted. At the same time, however, the aquaculture industry is urgently required to establish sediment treatment technology from the viewpoint of increasing the oxygen concentration in water.

Conventionally, as a method of supplying oxygen to a culture pond that requires oxygen, there are a water turbine method, an air diffuser method (a method of injecting high-pressure air into a porous plate or tube), a jet water flow method, and the like. However, none of the methods has an oxygen dissolution efficiency of more than 20%. These systems are designed to emphasize the water circulation of the entire pond rather than the generation of bubbles. This cannot increase the amount of dissolved oxygen at the bottom of the pond. As a result, the activity of microorganisms that decompose and purify sedimentary organic matter is not activated, and massive deaths due to disease occur. As a result, the water in the pond has to be replaced in large quantities. In addition, by replacing a large amount of water in the pond, sediment-laden oxygen-free water is released into rivers and oceans. For this reason, there is a concern about the occurrence of environmental pollution. For these reasons, there has been an increasing demand for the development of new equipment.

Yet another important point is that the issue of wastewater treatment is being socially highlighted. Wastewater treatment facilities such as chemical factories, paper mills, refineries, food processing factories, livestock, and commercial kitchens raise the same issues as those mentioned above for aquaculture ponds.

The object of the present invention has been made in view of the above-mentioned problems, and uses a shear force of water and a collapse impact force of a cavity to destructively decompose gas such as air. Efficiently disintegrating gas into water with high efficiency, e.g. efficiently increasing the amount of dissolved oxygen in the water near the bottom soil where organic matter accumulates in the water of aquaculture ponds, or efficiently treating wastewater Another object of the present invention is to provide a high-efficiency gas dissolving apparatus having good performance. Disclosure of the invention

The high-efficiency gas dissolving apparatus according to the present invention is configured as follows to achieve the above object.

The high-efficiency gas dissolving apparatus according to the present invention includes a water supply section that discharges high-pressure water from a water injection port from a water discharge port, and a gas supply port that is provided with a gas introduction port to mix gas into high-pressure water by an ejector action. A nozzle body having a hole, a large-diameter nozzle portion having an internal space expanded toward the front side, and having a large-diameter nozzle portion that positively generates cavitation due to the flow of high-pressure water discharged from the water discharge port of the water guide portion; And a collision member that is disposed further to the front of the nozzle body with a gap therebetween, and that disperses water containing microbubbles discharged from the enlarged-diameter nozzle portion to the periphery.

According to the above configuration, when the cavitation generated in the negative pressure area in the internal space of the enlarged diameter nozzle section collapses in the positive pressure area, a local impact pressure is applied and the bubbles are destructively miniaturized. The cavity is always standing in the internal space of the enlarged nozzle, and the generation and collapse of bubbles are repeated. In addition, by providing the collision member, fine gas bubbles such as air can be diffused around the high-efficiency gas dissolving apparatus. Here, the “gas (gas)” includes a gas containing oxygen and ozone in addition to air, and the present invention can be applied to any other gas.

In addition, the description mainly focuses on a configuration in which a gas such as air, oxygen, or ozone is dissolved in water, but is not limited thereto. In general, the high-efficiency gas dissolving apparatus according to the present invention can also be used for dissolving a gas in a liquid or fluid other than water.

With the above configuration, the shearing force of the fluid and the cavitation are broken. The local impact pressure generated when the air bubbles are applied can make the air bubbles finer. As a result, it is possible to increase the ratio of the amount of dissolved gas to the amount of gas supplied to the water, and to improve the efficiency of breeding in small spaces, such as aquaculture ponds such as shrimp and eel. It is promising, and the effect will be enormous.

It uses less power and is energy saving compared to conventional products. In addition, the nozzle is further miniaturized by having a nozzle body and a collision member that is disposed with a gap further on the front side of the nozzle body and that disperses water containing microbubbles discharged from the enlarged-diameter nozzle to the periphery. Gas bubbles can be uniformly diffused around the high-efficiency gas dissolving device.

Further, it is extremely useful for the treatment of wastewater for industry and daily life.

In the above-described high-efficiency gas dissolving apparatus according to the present invention, the enlarged internal space (nozzle hole) in the enlarged diameter nozzle portion is shaped like a truncated cone, and the opening angle is set in the range of 40 to 90 degrees. Formed. As a result, the cavity can be kept inside the enlarged nozzle without going out of the internal space of the enlarged nozzle.

For this reason, the local impact pressure generated when the cavitation is broken is applied to other bubbles, making the bubbles finer and increasing the ratio of the amount of gas dissolved to the amount of gas supplied to water.

In the above-described high-efficiency gas dissolving apparatus according to the present invention, the collision member has a disk shape, and a surface facing the enlarged-diameter nozzle portion preferably has a downward slope in a radial direction from the center to the peripheral portion. Or, preferably, it is formed to be flat. The collision member is fixed using a plurality of support rods. As described above, since the collision member is inclined downward in the radial direction from the center toward the peripheral portion, the fine gas bubbles existing in the space between the enlarged nozzle portion and the collision member are formed. Can be stirred mechanically In addition, it can diffuse uniformly around the high-efficiency gas dissolving device.

In addition, by fixing the collision member to the nozzle body with a plurality of support ports, the flow rate of the high-pressure water sent to the water inlet and the scale of the high-efficiency gas dissolving device, and the distance between the nozzle body and the collision member Can be adjusted. Thereby, under each condition, it is possible to create an optimum state in which water containing fine bubbles can be diffused around the high-efficiency gas dissolving apparatus.

In the high-efficiency gas dissolving apparatus according to the present invention described above, the enlarged inner surface of the front end of the enlarged diameter nozzle portion may be smoothly rounded. The radius of curvature in this case is preferably, for example, 10 to 5 Omm. Thereby, the gas bubbles of the fine gas present in the internal space of the enlarged diameter nozzle portion can smoothly move around the high-efficiency gas melting device along the inner inner wall surface.

In the above-described high-efficiency gas dissolving apparatus according to the present invention, the water guide section is provided with a throttle section on the downstream side, and the throttle section is provided with a gas inlet. This makes it possible to make the velocity distribution between the central portion and the wall surface of the high-pressure water passing through the constricted portion uniform, so that high-pressure water having a uniform flow velocity can be produced. In addition, high-pressure water mixed with many gases can be discharged. Therefore, the efficiency of dissolving gas in water can be increased. BRIEF DESCRIPTION OF THE FIGURES

FIG. 1 is a longitudinal sectional view of a high-efficiency gas dissolving apparatus according to one embodiment of the present invention.

FIG. 2 shows a collision plate of the high-efficiency gas dissolving apparatus according to the present embodiment, where (A) is a plan view of the collision plate, and (B) is obtained by cutting along a line BB passing through the center of the collision plate. It is a longitudinal cross-sectional view.

FIG. 3 shows an operation state of the high-efficiency gas dissolving apparatus according to the present embodiment, (A) is a diagram illustrating an operation state in submerged soil, and (B) is a diagram illustrating an operation state in a gas dissolving device. BEST MODE FOR CARRYING OUT THE INVENTION

Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings.

As shown in FIGS. 1 to 3, a high-efficiency gas melting apparatus 10 according to an embodiment of the present invention has a nozzle main body 11 and a nozzle main body 11 arranged with a gap at the front end thereof. And a collision plate 18.

The nozzle body 11 is composed of a water introduction section 14 and an enlarged diameter nozzle section 17. The external shape of the nozzle body 11 has a cylindrical shape as a whole. Each of the water guide section 14 and the enlarged diameter nozzle section 17 is a member having a cylindrical shape in appearance. The collision plate 18 is an example of a collision member. The collision plate 18 has a substantially disk shape.

As shown in FIG. 1, the water guide section 14 of the nozzle body 11 has an inlet hole 14a formed with a water inlet 12 on the upper side and a water outlet 13 on the lower side. The water guide hole 14a is formed as a through hole along the central axis of the water guide portion 14 having a cylindrical shape. The high-pressure water accelerated to 20 to 5 OmZsec, which is sent via a pump 19 (see (A) in Fig. 3), which is an example of water transport means, is supplied to the water inlet 14 of the water inlet 14 And is discharged from the spout 13.

Further, as shown in FIG. 1 and FIG. 3 (B), a gas supply hole 16 is provided through a gas introduction port 15 to a narrowed portion 22 provided downstream of the introduction portion 14. Air, which is an example of gas, is mixed into the high-pressure water that passes through the water introduction section 14. That is, as the high-pressure water rapidly rises in the squeezing part 22, a negative pressure phenomenon occurs, and the air naturally sucked (ejector action) from the gas supply hole 16 in the discharge direction of the high-pressure water is Mixed with high pressure water. The inner outlet of the gas supply hole 16 is connected to the narrowed portion 22 of the inlet 14 as the gas inlet 15. A gas pipe (not shown) for supplying gas from the outside is connected to the outside inlet of the gas supply hole 16.

An enlarged-diameter nozzle portion 17 is physically connected to the end face of the water introduction portion 14 on the side of the water discharge port 13. The enlarged diameter nozzle portion 17 has a substantially cylindrical shape whose external length is relatively short in the axial direction, and has a diameter substantially equal to that of the water guide portion 14. In addition, the water introduction part 14 and the enlarged diameter nozzle part 17 can be integrally formed by a technique such as resin molding. The enlarged-diameter nozzle portion 17 has a nozzle hole as an internal space at the central axis. The diameter of the nozzle hole is enlarged so that the diameter of the base portion is small and the diameter of the front portion is gradually increased. As for the nozzle hole formed in the enlarged diameter nozzle portion 17, the shape of the space formed by the hole is a truncated cone as shown in FIG. That is, the nozzle hole formed in the enlarged-diameter nozzle portion 17 (or the inner wall surface or the inner surface forming the nozzle hole in the enlarged-diameter nozzle portion 17) is a tape whose diameter is increased from the base side to the front side. It is formed as a hole or divergent hole. The opening angle of the nozzle hole of the enlarged diameter nozzle portion 17 is preferably 40 to 90 degrees.

The high-pressure water mixed with air discharged from the water discharge port 13 of the nozzle body 11 actively generates a cavity in the internal space (nozzle hole) of the enlarged-diameter nozzle section 17. In other words, when the flow velocity of the high-pressure water flow (jet water flow) increases, the static pressure of the water decreases, and the pressure of the water falls below the saturated vapor pressure (negative pressure region), causing cavitation.

Since the inner space of the enlarged diameter nozzle portion 17 has a divergent shape, in addition to the conventional shearing action of the jet, a stronger shearing force (gas tearing off) is generated. Also, the cavitation generated in the negative pressure region is (A region where the water pressure recovers to a positive pressure due to the stagnation flow on the wall surface side of the enlarged diameter nozzle portion 17) When collapsing, the local impact pressure is applied, and the bubbles are made finer.

As described above, the cavitation is always present in the internal space of the enlarged-diameter nozzle portion 17, and the generation and collapse of the cavitation are repeated, and a strong shear force acts efficiently and locally. This destructively miniaturizes the air, increases the surface area of the air in contact with the water, and allows more air (oxygen) to be dissolved in the water.

As shown in FIGS. 1 and 2 (A) and (B), the surface of the disk-shaped collision plate 18 preferably has a downward slope from the center to the peripheral edge in the radial direction. Made in. Also, the surface of the collision plate 18 can be made to have a preferably flat surface shape. The collision plate 18 is fixed to the enlarged nozzle 17 (nozzle body 11) by, for example, four support rods 21. The inclined surface of the impingement plate 18 faces a large-diameter outlet (the lower opening in FIG. 1) in the internal space of the enlarged-diameter nozzle 17. By providing such a collision plate 18, it is possible to effectively disperse the water mixed with fine bubbles generated in the inner space of the enlarged diameter nozzle portion 17 around the high-efficiency gas dissolving device 10. The water mixed with microbubbles squirted diagonally downward in an annular shape increases the oxygen concentration in the bottom soil. The number of the support rods 21 may be any number as long as the collision plate 18 can be stably attached to the enlarged-diameter nozzle portion 17 (nozzle body 11). By fixing the impingement plate 18 to the enlarged-diameter nozzle portion 17 by the support rod 21, depending on the flow rate of the high-pressure water introduced into the water inlet 12 and the scale of the high-efficiency gas dissolving device 10. The distance between the enlarged nozzle portion 17 (nozzle body 11) and the collision plate 18 can be adjusted. Therefore, under each condition, it is possible to create an optimal state around the high-efficiency gas dissolving device 10 where water containing fine bubbles can be discharged. Wear. At this time, the mounting method of the support rod 21 may be any as long as it can be mounted and fixed. For example, it is possible to provide a hole 18a in the collision plate 18 and attach it with a port or a screw or the like, and it is also possible to attach it by welding or the like. Further, since the collision plate 18 can change the radius of the collision plate 18 according to the scale of the high-efficiency gas dissolution apparatus 10, fine bubbles are mixed around the high-efficiency gas dissolution apparatus 10 under each condition. It is possible to create an optimal condition for dissipating water.

In the present embodiment, water is supplied to the nozzle body 11 by the hose 19a. However, the hose may be any hose that can withstand a water speed of 20 to 50 / sec. It may be a metal or vinyl hose or tube. Reference numeral 20 denotes a nipple bonded when the hose 19a is connected to the nozzle body 11 of the high-efficiency gas dissolving apparatus 10 so that the supplied water does not leak. Instead of the nipple 20, another sealing member that can prevent water leakage may be used.

The opening angle of the internal space of the enlarged diameter nozzle section 17 was set in the range of 40 to 90 degrees. The reason is as follows. When the opening angle is less than 40 degrees, in the high-pressure water flow discharged from the water discharge port 13 of the nozzle body 11, the central portion where the flow velocity is the fastest in the internal space of the enlarged diameter nozzle portion 17, and the slowest portion This is because there is no significant velocity distribution at the wall and no significant shearing force of the fluid is generated, so that air bubbles cannot be miniaturized. On the other hand, when the opening angle exceeds 90 degrees, water is drawn into the internal space of the enlarged nozzle 17 from around the high-efficiency gas dissolving device 10, and the internal space of the enlarged nozzle 17 is generated. This is because no good shearing force can be generated between the central portion and the wall portion in the above, and it is no longer possible to reduce the size of bubbles by cavitation. From the above, the opening angle of the internal space of the enlarged diameter nozzle section 17 is further 50 to 70 degrees. Is more preferable, and most preferably 60 degrees.

The enlarged inner surface of the front end forming the inner space of the enlarged nozzle 17 is smoothly rounded by setting its radius of curvature to 10 to 50 mm. As a result, fine air bubbles existing in the internal space of the enlarged nozzle 17 are uniformly distributed around the high-efficiency gas dissolving device 10 along the inner and lower surfaces of the enlarged nozzle 17. In addition, it can be diffused smoothly and smoothly. Note that the enlarged inner surface of the front end of the enlarged diameter nozzle portion 17 may be formed in a curved shape or an angular shape.

Although the high-efficiency gas dissolving apparatus 10 sets the discharge direction of the high-pressure water at the bottom of the water, the discharge direction may be any direction.

The material of the nozzle body 11 of the high-efficiency gas dissolving device 10 is a material that does not spread in water and a material that can withstand high-pressure water. For example, it may be made of metal such as stainless steel, hard resin, or plastic. In the present embodiment, an example in which air is dissolved in water has been described as an example of the gas. However, the present invention is also applicable to a gas containing oxygen and ozone.

Next, an example is described about a specific application example.

Using a high-efficiency gas dissolution apparatus 10, high-pressure water with a pressure of 35.8 liters (L) per minute and a water pressure of 2 kgf / cm 2 (almost 19.6 N / cm ² ) is introduced from the water inlet 12 Then, the air was dissolved. As a result, the bubble diameter of the micronized air was 0.01 to 0.1 mm. Also power of pump 19

(Power consumption) was 0.4 kW, which was lower than the conventional 11 kW. Furthermore, the oxygen dissolution efficiency (the ratio of the dissolved oxygen amount to the supplied oxygen amount, which is an index for increasing the amount of oxygen in water) was 40% or more. Next, the characteristics of the existing oxygen supply device and the power consumption The cost and oxygen dissolution efficiency are shown.

In the diffuser system, when high-pressure air passes through a porous material charged in water, the air is fined. The bubble diameter is as large as 5 mm or more and the residence time in water is short, so the oxygen supply effect is low. The power consumption of this oxygen supply device is 11 kW, and the oxygen dissolution efficiency is 4.8%.

The jet water jet method is a method in which a water jet is sprayed into water from a nozzle together with air to supply oxygen. In the conventional nozzle shape and the free space jet method, since large bubbles are generated together with the fine bubbles, the fine bubbles are attracted to the large bubbles and rise rapidly, so that the residence time of the bubbles is short. The power consumption of this oxygen supply device is 11 kW and the oxygen dissolution efficiency is 0.8%. The water turbine method is the most popular product in the aquaculture industry because of its low price. However, the only effect is to create a water stream, and the oxygen concentration increases only near the water surface. The power consumption of this oxygen supply device is 0.75 kW, and the oxygen dissolution efficiency is 0.5%. Industrial applicability

The high-efficiency gas dissolving apparatus according to the present invention makes the gas fine and dissolves it in water or the like with extremely high efficiency, and efficiently increases the amount of dissolved oxygen in the water near the bottom soil where the organic matter is deposited in the water of the aquaculture pond. Efficient wastewater treatment in industrial or industrial wastewater treatment facilities, domestic wastewater treatment facilities, etc., and good economic efficiency.

Claims

The scope of the claims

1. A water supply section for discharging high-pressure water from the inlet through the discharge port, a gas supply port provided with a gas introduction port in the water supply section to mix gas into the high-pressure water by an ejector action, A nozzle body having an internal space whose diameter is enlarged toward the nozzle and comprising a large-diameter nozzle portion for generating cavitation by flowing the high-pressure water discharged from the discharge port into the internal space;

A high-efficiency gas dissolving device, comprising: a collision member that is disposed with a gap on the front side of the nozzle body and that disperses the high-pressure water mixed with microbubbles discharged from the large-diameter nozzle to the periphery. apparatus.

2. The high-efficiency gas dissolving apparatus according to claim 1, wherein an opening angle of the enlarged inner space in the enlarged nozzle portion is included in a range of 40 to 90 degrees.

3. The collision member has a disk shape, and is formed such that a surface facing the enlarged-diameter nozzle portion has a downward slope from a center to a peripheral portion in a radial direction. 3. The high-efficiency gas dissolving apparatus according to claim 1 or 2.

4. The high-efficiency gas according to any one of claims 1 to 3, wherein a front-side inner surface of the enlarged-diameter nozzle portion forming the enlarged internal space is smoothly rounded. Melting equipment.

5. A high-efficiency gas according to any one of claims 1 to 4, wherein a throttle is provided on the downstream side of the water guide, and the gas inlet is provided in the throttle. Melting equipment.