JPH08230762A - Equipment for generating micro bubble - Google Patents

Abstract

PURPOSE: To reduce the energy consumption by ejecting the compressed air into a fluid transfer pipe through a fiber film to generate bubbles, and efficiently generating the bubble-water mixed fluid containing fine bubbles with a simple structure. CONSTITUTION: When a pressurized water feeding system 1 is operated, the pressurized water is fed into a fluid transfer pipe 3 to generate the flowing water, and ejected from a bubble-water mixed fluid ejecting part 9 into the sea water. When a compressed air feeding system 2 is operated, the compressed air is fed from a compressed air transfer pipe 4 into a communicating part 5, and ejected into the fluid transfer pipe 3 through a branched pipe 4a, a braided sleeve 6, a fiber film 7, and pores 8a in a masking layer 8 in this order. The compressed air is ejected from the pores 8a in the masking layer 8 as the air flow of small diameter, and a number of bubbles of small diameter are generated and transferred to the bubble-water mixed fluid ejecting part 9. Bubbles are ejected from a fluid ejecting port 11 provided on a submerged surface 10 of a navigating vehicle device diagonally rearward of the navigating vehicle to reduce the friction of the navigating vehicle.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a microbubble generator used for reducing the friction of a vehicle.

[0002]

2. Description of the Related Art In order to reduce the friction of a ship or the like, a method has been proposed in which a bubble or an air layer is interposed on the surface of the hull. Techniques for ejecting bubbles into water include (1) JP-A-50-83992 and (2) JP-A-53-13628.
No. 9, (3) JP-A-60-139586, (4) JP-A-61-71290, (5) Jitsukai 61-39691.
No. 6, (6) Japanese Utility Model Publication No. 61-128185 is proposed.

In these techniques, as a method of ejecting bubbles, pressurized air generated by an air pump is ejected into water through a plurality of holes or perforated plates.

[0004]

However, since the above-mentioned techniques (1) to (6) have the following problems, none of them is practically used. (a) With the method of ejecting only pressurized air from a plurality of holes, it is difficult to obtain fine bubbles, the bubbles easily separate from the hull due to the lifting force based on the buoyancy, and the frictional resistance reduction range becomes small. (b) In the technology that blows out minute bubbles directly from the porous plate to the outside of the hull, the total of energy consumption due to pressure loss when bubbles are blown on the porous plate and the energy consumption to jet outside the hull become large, resulting in friction. More energy is consumed to blow bubbles than to save energy by reducing resistance.

The present invention has been made in view of these circumstances, and has the following objects. To generate a bubble-water mixed fluid containing fine bubbles with low energy consumption. To facilitate the setting of the air blowing position and to hold the air bubbles by suppressing the mutual contact of air bubbles. To make it easy to secure a flow path for pressurized air and improve the ability to send pressurized air. To simplify the structure of the bubble generation part and improve the adaptability to changes in specifications. Make it easy to adjust the amount of bubbles and the flow rate of fluid.

[0006]

A micro-bubble generating device according to the present invention comprises a fluid transfer pipe connected to a pressurized water supply means and a communication portion disposed inside the fluid transfer pipe and in communication with the inside and outside. The pressurizing gas transfer pipe is provided, and the pressurizing gas supply means is connected to the pressurizing gas transfer pipe and sends the pressurizing gas to eject the pressurizing gas into the fluid transfer pipe through the communicating part. The technology to provide the membrane is adopted. In this case, it is preferable to also use a technique of supporting the fiber membrane with a metal net, for example, in a configuration in which the fiber membrane is located on the fluid side. Furthermore, it is more preferable to form a plurality of through holes in the tube wall of the pressurized gas transfer tube and dispose the metal net on the tube wall in the area where these through holes are formed. As the fiber film used at this time, for example, a fiber film made of synthetic fiber is suitable, and as the metal net, for example, a metal net / braided sleeve made of stainless steel is suitable. On the other hand, as another means in the device for generating microbubbles, a casing, a fiber membrane that is arranged in parallel inside the casing and divides the pressurized water plenum portion and the pressurized air plenum portion, and is connected to the pressurized water plenum portion. The technique employs a pressurized water supply means arranged in a state and a pressurized gas supply means arranged in a connected state with respect to the pressurized air plenum portion. In any of the above microbubble generators, it is preferable to use a technique of arranging a masking layer having a large number of pores on the fiber membrane, for example, a technique of arranging a masking layer on the side of the fiber membrane on which the fluid flows. As the masking layer, for example, a synthetic resin-based paint, a rubber-based paint or the like applied and solidified by screen printing, or a plastic film such as a heat-shrinkable film adhered thereto is suitable. Further, the following techniques are effective in the present invention. 1) Applicable to gases other than air and liquids other than water. 2) To set various combinations such as the pore diameter, the number, the gas amount, and the transfer speed of running water of the fiber membrane and the masking layer.

[0007]

The pressurized water from the pressurized water supply means is sent to the inside of the fluid transfer pipe or the pressurized water plenum part, and the pressurized air from the pressurized gas supply means is sent to the pressurized gas transfer pipe or the pressurized air plenum part. And is jetted into the fluid flowing through the fluid transfer pipe or the pressurized water plenum through the fiber membrane and the masking layer. Since the pressurized air is ejected through the fiber membrane and the masking layer, a thin air flow corresponding to the pore diameter of the fiber membrane and the masking layer is formed from multiple locations, and the air flow is easily divided. , It is cut by running water and many small bubbles (micro bubbles) are generated. A large number of these bubbles are mixed with running water, and thereafter, are transferred to a desired position in the fluid transfer pipe or the pressurized water plenum while maintaining the small bubble diameter. Since the fiber membrane is supported by the metal net, the rigidity is increased. Also, when a masking layer having a large number of pores is arranged in the fiber membrane, the diameter and spacing of these pores can be set arbitrarily, and the spacing is secured between adjacent bubbles, It is possible to suppress the occurrence of the bubble enlargement phenomenon due to the contact between the adjacent bubbles.

[0008]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the microbubble generator of the present invention will be described below with reference to the drawings.

[First Embodiment] FIGS. 1 and 2 show a first embodiment of a microbubble generator according to the present invention. In the drawings, reference numeral 1 is a pressurized water supply system (pressurized water supply means). 2 is a pressurized air supply system (pressurized gas supply means),
3 is a fluid transfer pipe, 4 is a pressurized air transfer pipe (pressurized gas transfer pipe), 5 is a communicating portion, 6 is a braided sleeve (metal mesh), 7 is a fiber membrane, 8 is a masking layer, and 9 is bubble water mixing. The fluid ejection part is shown.

The pressurized water supply system 1 is, for example, a water inlet provided on the submerged surface of a ship, a pump for absorbing seawater (water) to generate pressurized water, a control means for controlling the flow rate / pressure of the pressurized water, and a water supply pressure. A water supply pressure gauge for measuring water, a liquid meter for measuring the water supply, etc. are applied.
It is connected to the fluid transfer pipe 3.

The pressurized air supply system 2 is a blower for sucking and pressurizing air (atmosphere), and a flow rate of air (atmosphere).
A device having a control mechanism for controlling the pressure is applied and is connected to the pressurized air transfer pipe 4.

The fluid transfer pipe 3 is connected between the pressurized water supply system 1 and the bubbling water mixed fluid jetting portion 9.

As shown in FIG. 1, the pressurized air transfer tube 4 penetrates the tube wall of the fluid transfer tube 3 in an airtight manner, and the fluid transfer tube 3 is provided.
Of the branch pipe 4a is inserted into the inside of the
The communication portion 5 is arranged by utilizing a.

As shown in FIG. 2, the communicating portion 5 has a plurality of branch pipes 4a formed with an appropriate number of through holes 4b.
The braided sleeve 6, the fiber film 7 and the masking layer 8 are sequentially laminated in the outer periphery of the branch pipe 4a in the area where the through holes 4b are formed. At the tip of the branch pipe 4a, a closing portion 4c in which the pipe hole is closed by attaching a cap or the like is arranged, and in order to secure the overall strength of the branch pipe 4a and the communicating portion 5 in the vicinity of the closing portion 4c. The supporting wings 5a of the above are integrally arranged.

The braided sleeve 6 integrally covers the through hole 4b of the branch pipe 4a and supports the fiber membrane 7 in a state where a hollow layer through which pressurized air is inserted is formed. The braided sleeve 6 is made of stainless wire. Braided sleeves, etc. are applicable.

The fiber membrane 7 is made of, for example, 100% polyester cloth or the like, which is arranged in close contact with the braided sleeve 6 and has a large number of weaves for dividing and inserting the air flow.

The masking layer 8 is formed by thinly forming a synthetic resin coating film on the outer surface of the fiber film 7 by a method such as screen printing and also covering a large number of the weaves of the fiber film 7 with a space between them. To form a large number of pores 8a. The diameter of the pores 8a is, for example, about 100 μm, and the interval between the pores 8a is set according to a predetermined air flow rate.

The bubbling water mixed fluid jetting portion 9 is provided on a submerged surface 10 which is a friction reduction target surface of a navigation body such as a ship, and is connected to a fluid transfer pipe 3 so that air and water can be supplied as desired. It has a plurality of fluid ejection ports 11 for ejecting the bubbly water mixed fluid mixed at a ratio into seawater (water), for example, obliquely rearward of the running body.

In the micro-bubble generator having the above-described structure, when the pressurized water supply system 1 is operated, the pressurized water is sent to the fluid transfer pipe 3 to generate running water inside the fluid transfer pipe 3. Bubbling water mixed fluid jetting portion 9 jets it into seawater (water).

When the pressurized air supply system 2 is operated,
Pressurized air is sent from the pressurized air transfer pipe 4 into the inside of the communication part 5, and passes through the branch pipe 4a, the braided sleeve 6, the fiber membrane 7, and the pores 8a of the masking layer 8 in that order to the fluid transfer pipe 3. It is made to spout in. The pressurized air is jetted from the pores 8a of the masking layer 8 as a thin air flow, so that the pressurized air is in a state of being easily cut, and is also cut by the intersection with running water to generate air bubbles (micro bubbles) having a small diameter. A large number of them are generated and mixed with running water, and thereafter, bubbles having a small diameter are transferred to the bubble-water mixed fluid jetting unit 9 by the fluid transfer pipe 3 as they are.

The bubbling water mixed fluid obtained as described above is used as the fluid jet 11 provided on the submerged surface 10 of the vehicle.
It is jetted obliquely rearward of the vehicle and is used for reducing the friction of the vehicle, and is jetted obliquely rearward of the vehicle to act as propulsive force of the vehicle.

In the above-mentioned micro-bubble generator, the main pressure loss at the time of producing the bubble-water mixed fluid is
It occurs in the communication section 5. The communication portion 5 is composed of a branch pipe 4a having a through hole 4b, a braided sleeve 6, a fiber membrane 7, and a masking layer 8 having pores 8a. The main pressure loss in the communication portion 5 is the masking layer 8 It can be considered that it is based on the insertion resistance of the pores 8a. Therefore, the generation of the bubbly water mixed fluid can be achieved with a small energy consumption.

[Second Embodiment] FIG. 3 shows a communication part 5 in a second embodiment of the micro-bubble generator according to the present invention.
In comparison with the first embodiment, the branch pipe 4a and the fiber membrane 7 are omitted, and the braided sleeve 6 having rigidity is fixed to the tip of the pressurized air transfer pipe 4 with a length L.
And a large number of pores 8a formed on the braided sleeve 6.
And a masking layer 8 having Even in the second embodiment, it is possible to obtain the same effects as the first embodiment.

[Third Embodiment] FIG. 4 shows a third embodiment of the microbubble generator according to the present invention. Reference numeral 20 is a casing, 21 is a pressurized water plenum portion, and 22 is a pressurized air plenum portion. Is shown.

The casing 20 is formed in a rectangular tube shape, is arranged in a connected state between the pressurized water supply system 1 and the bubbling water mixed fluid jetting section 9, and has a plurality of fiber membranes attached in parallel to each other. 7 and the layered spaces are alternately formed as a pressurized water plenum portion 21 and a pressurized air plenum portion 22. Further, a pressurized air transfer pipe 4 for guiding the pressurized air (pressurized gas) from the pressurized air supply system 2 to each pressurized air plenum 22 is attached to a side portion of the casing 20 in a connected state. There is. In addition, at the upstream end of the casing 20, as shown in FIG.
As shown in (b), a header 23 that facilitates connection with the fluid transfer pipe 3 is disposed, and a triangular guide plate 24 is provided between the upstream end of the fiber membrane 7 and the casing 20. It is attached so as to stretch 7. Further, the connecting portion between the casing 20 and the bubbling water mixed fluid ejection portion 9 has the same structure. The above-mentioned masking layer 8 is arranged on the surface of the fiber film 7.

In the third embodiment constructed as described above, as shown by the arrow in FIG. 4B, the pressurized water is sent to the pressurized water plenum portion 21 and the pressurized air is transferred by the pressurized air. The compressed air is sent into the inside of the pressurized air plenum portion 22 via the pipe 4, and the pressurized air is ejected to the pressurized water plenum portion 21 via the fiber membrane 7. At this time, since running water is generated inside the pressurized water plenum portion 21, the pressurized air is divided by the fine pores 8a of the fiber membrane 7 and the masking layer 8 to form a thin air flow, which jets out and intersects with the running water. Bubbles with a small diameter (micro bubbles) that are cut by
Are generated in large numbers. Thereafter, the bubble-water mixed fluid containing fine bubbles is transferred to the bubble-water mixed fluid jetting section 9.

[0027]

The microbubble generator of the present invention has the following effects. (1) By injecting pressurized air into the fluid transfer pipe via the fiber membrane to generate bubbles, it is possible to efficiently generate a bubble-water mixed fluid containing fine bubbles with a simple structure. Energy consumption is lower than that in the case of directly generating bubbles. (2) When the pores of the masking layer are formed in a state of having an interval, an interval is ensured between the bubbles that are generated adjacent to each other, and contact between adjacent bubbles can be suppressed to hold the bubble particles. it can. (3) By transferring the bubbles as the bubble-water mixed fluid to the bubble-water mixed fluid jetting portion, it is possible to easily adjust the amount of bubbles and the flow rate of the fluid, and to improve the feedability. (4) By providing the fiber film or the masking layer on the metal net or the pressurized gas transfer pipe, the structure of the bubble generating portion can be simplified and the adaptability to the specification change can be improved.

[Brief description of drawings]

FIG. 1 shows a first embodiment of a micro-bubble generator of the present invention, (a) is a partially sectional front view,
(B) is a sectional view taken along the line XX in (a).

FIG. 2 is a perspective view and an enlarged cross-sectional view showing the communicating portion of FIG.

FIG. 3 is a partially sectional front view showing a communication part in a second embodiment of the microbubble generator according to the present invention.

4A and 4B are a perspective view and a cross-sectional view showing a third embodiment of a micro-bubble generator according to the present invention, in which a part of the description is omitted.

[Explanation of symbols]

 1 pressurized water supply system (pressurized water supply means) 2 pressurized air supply system (pressurized gas supply means) 3 fluid transfer pipe 4 pressurized air transfer pipe (pressurized gas transfer pipe) 4a branch pipe 4b through hole 4c closed part 5 communication Part 5a Supporting blade 6 Braided sleeve (metal mesh) 7 Fiber film 8 Masking layer 8a Pore 9 Bubble water mixed fluid ejection part 10 Submerged surface 11 Fluid ejection port 20 Casing 21 Pressurized water plenum part 22 Pressurized air plenum part 23 Header 24 Guide plate

 ─────────────────────────────────────────────────── ─── Continuation of front page (72) Yoshiaki Takahashi, Yoshiaki Takahashi, 2-1-1 Toyosu, Koto-ku, Tokyo Ishikawajima Harima Heavy Industries, Ltd. Tokyo No. 1 factory (72) Osamu Watanabe Shinchu, Isogo-ku, Yokohama-shi, Kanagawa Haramachi No. 1 Ishikawajima-Harima Heavy Industries Co., Ltd. Technical Research Institute (72) Inventor Hideo Mitsutake No. 1 Shin-Nakahara-cho, Isogo-ku, Yokohama-shi, Kanagawa Ishikawajima Harima Heavy Industries Co., Ltd. Technical Research Institute (72) Inventor Shoichi Maruyama Yokohama, Kanagawa No. 1 Shin-Nakahara-cho, Isogo-ku, Ishi Ishikawajima Harima Heavy Industries Ltd. Technical Research Institute

Claims (5)

[Claims] 1. A device for generating a bubbling water mixed fluid, comprising a fluid transfer pipe (3) connected to a pressurized water supply means (1).
A pressurized gas transfer pipe (4) provided inside the fluid transfer pipe and having a communication part (5) for communicating the inside and the outside, and a pressurized gas connected to the pressurized gas transfer pipe to send pressurized gas. A device for generating microbubbles, comprising: a pressurized gas supply means (2) for ejecting into a fluid transfer pipe via a communication part, and a fiber membrane (7) provided in the communication part. 2. Microbubble generator according to claim 1, characterized in that the fiber membrane (7) is supported by a metal mesh (6). 3. A plurality of through holes (4b) are formed on the pipe wall of the pressurized gas transfer pipe (4), and a metal mesh (6) is arranged on the pipe wall in the range where the through holes are formed. The microbubble generator according to claim 2, wherein 4. A device for generating a bubbling water mixed fluid, comprising: a casing (20); and a pressurized water plenum portion (21) and a pressurized air plenum portion (22) arranged in parallel inside the casing. The partitioning fiber membrane (7), the pressurized water supply means (1) arranged in a connected state to the pressurized water plenum portion, and the pressurized gas supply means (2) arranged in a connected state to the pressurized air plenum portion. ) And a micro-bubble generator. 5. The device for generating microbubbles according to claim 1, 2, 3 or 4, wherein the fiber membrane (7) is provided with a masking layer (8) having a large number of pores (8a). .