JPH08229372A - Microbubble jetting device - Google Patents

Abstract

PURPOSE: To reduce energy loss on transfer of a bubble-water mixed fluid to a jetting port and to save a space of a flow passage of the bubble-water mixed fluid corresponding to the shape of the jetting port. CONSTITUTION: A device is provided with a flow passage structure 10 for transferring a bubble-water mixed fluid, and a slit-shaped fluid jetting port 3 arranged connected to the fluid passage structure 10 and for jetting the bubble-water mixed fluid. The flow passage structure 10 has a fluid transfer pipe 11 having a circular flow passage section, a pyramid part 12 connected to the tip of the fluid transfer pipe 11 with the shape of the flow passage section being changed from a circle to a rectangle, and an enlarged part 13 connected to the pyramid part 12 with the shape of the flow passage being gradually changed from a rectangle to a slit.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a jetting device for microbubbles which is used when reducing the friction of a vehicle by utilizing a fluid mixture of bubbles and water.

[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, with the method of ejecting only pressurized air from a plurality of holes, it is difficult to obtain fine bubbles, and the bubbles easily separate from the hull due to the lifting force based on buoyancy. In the technology that reduces the frictional resistance reduction range and blows out fine bubbles from the porous plate, the energy consumption based on the pressure loss when bubbles are blown out on the porous plate becomes large, and the energy saving by reducing the frictional resistance is more important than the energy saving. There is a drawback that the energy consumption for blowing out is increased and the practicality is impaired. In reality, none of the above-mentioned technologies (1) to (6) have been put to practical use. is there.

The present invention has been made in view of these circumstances, and has the following objects. To reduce energy loss during the transfer of bubbly water mixed fluid to the jet outlet. To equalize the flow velocity and flow rate of the bubbly water mixed fluid at the jet outlet and effectively reduce friction. To facilitate the guidance of the bubbly water mixed fluid from the fluid transfer pipe to the ejection port, and to improve the connectivity. To save space in the flow path of bubbly water mixed fluid that corresponds to the shape of the jet outlet.

[0006]

A microbubble ejection device according to the present invention ejects a bubble-water mixed fluid, which is arranged in a connection state with the flow-path constituting body for transferring the bubble-water mixed fluid. The flow path constituting body is provided with a slit-shaped fluid ejection port for allowing the flow path cross-sectional shape to be circular, and the flow path cross-sectional shape connected to the tip of the fluid transfer tube is changed from circular to square. A technique having a pyramidal portion in a state and a diffusing portion connected to the pyramid portion and having a cross-sectional shape of a flow path gradually deformed from a rectangular shape to a slit shape is adopted. A technique is adopted in which the cross-sectional area in the middle of the diffusion part is set to be equal to or larger than that of the fluid ejection port. The required number of the flow path components are arranged on the submerged surface of the hull such that the fluid ejection ports face rearward or obliquely rearward.

[0007]

The bubbly water mixed fluid generated by the bubbly water mixed fluid generating means is transferred to the micro-bubble jetting device arranged at various places on the hull. At this time, the bubbly water mixed fluid is transferred by the fluid transfer pipe and then sent to the pyramidal portion from the tip of the fluid transfer pipe having a circular flow path cross-sectional shape. In the pyramidal portion, the bubble-water mixed fluid is gradually spread based on the rectangular channel cross-sectional shape and taken over by the diffusion portion. In the diffusing section, the bubble-water mixed fluid is gradually diffused and deformed from a rectangular shape to a slit shape by the cross-sectional shape of the flow path and is guided to the slit-shaped fluid ejection port. The bubbly water mixed fluid thus spread in a slit shape based on the channel cross-sectional shape is jetted rearward from the fluid jet port along the submerged surface by static pressure and its own kinetic energy. When the bubbly water mixed fluid is ejected from the fluid ejection port, bubbles are present near the submerged surface to reduce the friction at the time of running and also to the direction opposite to the ejection direction of the bubbly water mixed fluid. A driving force is generated and becomes a driving force forward of the hull. If the cross-sectional area in the middle of the diffusion part is set to be larger than that of the fluid ejection port, the static pressure of the bubbly water mixed fluid will decrease in the middle of the diffusion part, and it will spread evenly over the enlarged flow passage section, and As the cross section of the flow channel becomes smaller, it is pressurized and jetted to the submerged surface. At this time, the bubbly water mixed fluid is ejected at a uniform flow rate and flow velocity in the length direction of the slit of the fluid ejection port.

[0008]

1 and 2 show an embodiment of a micro-bubble ejection device according to the present invention, wherein reference symbol A is a micro-bubble ejection device, Y is a friction-reducing vehicle, and E is friction-reduction. Target range (blowing area), 1 is a hull, 2 is a bubbly water mixed fluid generating means, 3 is a fluid ejection port, 4 is a submerged surface (hull surface), 5 is a propeller, 6 is a rudder, 7 is an air intake port. , 8
Indicates the water inlet.

At a suitable position of the hull 1 in the friction-reducing vehicle Y, a bubble-water mixed fluid generating means 2 to be described later is mounted, and the bubble-water mixed fluid generating means 2 has an air intake port 7 and a water intake port 8. It is connected to generate a bubbly water mixed fluid in a state where air and water are mixed at a desired ratio.

The details of the micro-bubble jetting device A will be described below. As shown in FIG. 2, the jetting device A is connected to the bubble-water mixed fluid generating means 2 and is a flow path for transferring the bubble-water mixed fluid. The structure 10 and a slit-shaped fluid ejection port 3 arranged in a connected state at the tip of the flow path structure 10 are provided.

The flow passage structure 10 is arranged inside the outer shell of the hull 1 shown in FIG. 1, and is provided with a fluid transfer pipe 11 for transferring the mixed fluid of bubbly water to various parts of the hull 1, and the fluid transfer. Tube 1
It has a pyramidal portion 12 connected to the tip of the No. 1 and a diffusion portion 13 connected to the pyramidal portion 12. The fluid ejection port 3 at the tip of the diffusing portion 13 is formed so as to extend obliquely rearward so as to penetrate the outer shell.

The cross-sectional shape of the flow path of each part of the flow path forming body 10 is
The fluid transfer pipe 11 has a circular shape, and the pyramidal portion 12 is set to be deformed from a circular shape to a rectangular shape and the flow passage cross section is gradually increased. Specifically, each flow path cross section is set so as to have a slit shape. Both the pyramidal portion 12 and the diffusion portion 13 are manufactured by, for example, a method of combining flat plate-shaped stainless steel plates and welding them.

The cross section of the flow path in each part of the flow path forming body 10 has a cross-sectional area S1 of the fluid transfer pipe 11 and a pyramidal portion 12
Of the fluid transfer pipe 11 is S2, the cross-sectional area of the connection of the pyramidal portion 12 with the diffusion portion 13 is S3, the cross-sectional area in the middle of the diffusion portion 13 is S4, and the opening of the fluid ejection port 3 is When the area is S5, it is set as follows. S1 = S2 S2 ≦ S3 ≦ S4 S5 ≦ S4 Therefore, the cross-sectional area S4 in the middle of the diffusion unit 13
Is set to be the largest.

In the micro-bubble jetting device A thus constructed, when the bubble-water mixed fluid generating means 2 is operated, the bubble-water mixed fluid in which air and water are mixed at a desired ratio as described above. Is generated, and this bubbling water mixed fluid is transferred to various parts of the hull 1 by the fluid transfer pipe 11,
The fluid is ejected from the fluid ejection port 3 at a desired position via the flow path structure 10. At this time, the bubbly water mixed fluid is sent to the pyramidal portion 12 from the fluid transfer pipe 11 having a circular flow path cross-sectional shape. In the pyramidal portion 12, the bubble-water mixed fluid is gradually spread based on the rectangular channel cross-sectional shape and is taken over by the diffusion portion 13. In the diffusion portion 13, the bubble-water mixed fluid is gradually diffused and deformed from a square shape into a slit shape by the cross-sectional shape of the flow path and is guided to the slit-shaped fluid ejection port 3. The bubbly water mixed fluid expanded in the slit shape based on the flow channel cross-sectional shape is jetted rearward from the fluid jet port 3 along the submerged surface by static pressure and kinetic energy of itself.

When the bubbly water mixed fluid is ejected from the fluid ejection port 3, bubbles having a small diameter (micro bubbles) are present in the vicinity of the submerged surface 4, and an effect of reducing friction during traveling is produced.
Further, the bubbly water mixed fluid is jetted out along the submerged surface 4, thereby acting as a propulsive force in the opposite direction. This propulsive force is transmitted to the hull 1 via the outer shell and becomes a driving force to the front of the hull 1. In this case, since the mass difference between air and water is three orders of magnitude, the generation of the propulsive force due to the jetting of the bubbling water mixed fluid is mainly based on the kinetic energy of water.

A cross-sectional area S4 in the middle of the diffusion section 13
However, if it is set to be larger than the opening area S5 of the fluid ejection port, the static pressure of the bubbly water mixed fluid becomes low in the middle of the diffusion portion 13, and the bubbly water mixed fluid becomes uniform based on the enlarged flow passage cross section. After being spread over the water, the submerged surface 4 passes through the fluid ejection port 3
Is ejected. At this time, the bubbly water mixed fluid is jetted at a uniform flow rate and flow velocity in the length direction of the slit of the fluid jet port 3. As described above, since the flow passage cross-sectional shape is gradually deformed from the circular shape to the slit shape, energy loss at the time of transfer due to the deformation of the flow passage cross-sectional shape is reduced.

On the other hand, FIG. 3 shows a bubble-water mixed fluid generating means 2
This is an example of the structure of the water suction port 8 and the pressurized water supply means 1
5, and a plurality of pores 16 formed in a part of the side wall (tube wall) of the flow path constituting body 10 in the longitudinal direction with a substantially uniform interval in the circumferential direction and the longitudinal direction. And the gas chamber 17 that surrounds the pores 16.
And a pressurized air supply means 18 connected to the internal space of the gas chamber 17.

When the bubbly water mixed fluid is generated by the bubbly water mixed fluid generating means 2, the pump of the pressurized water supply means 15 is operated to send seawater (water) into the flow path forming body 10, and Pressurized air supply means 18
By operating the blower of (1), pressurized air is sent into the internal space of the gas chamber 17 and ejected from a large number of pores 16 to generate a bubble-water mixed fluid in which bubbles are mixed. is there.

[0019]

The microbubble ejection device according to the present invention has the following effects. (1) Since the flow path cross-sectional shape is changed from a circular shape to a rectangular shape or a rectangular shape in the flow path structure portion to form a slit shape and the fluid transfer pipe and the fluid ejection port are connected to each other, the bubbling water mixed fluid is guided. It becomes smooth, and the energy loss at the time of transfer of the bubbly water mixed fluid due to the deformation of the flow path cross-sectional shape can be reduced. (2) Since the cross-sectional area in the middle of the diffusion part is set to be larger than that of the fluid ejection port, a bubbling water mixed fluid with a uniform flow velocity and flow rate is ejected from the fluid ejection port and sent along the submerged surface. Friction can be reduced. (3) Since the fluid transfer pipe is connected to the fluid ejection port via the pyramidal portion and the diffusion portion, it is possible to arrange the small diameter fluid transfer pipe at various places inside the hull up to the vicinity of the fluid ejection port. Space saving of the fluid transfer pipe corresponding to the shape of the fluid ejection port can be achieved.

[Brief description of drawings]

FIG. 1 is a partially omitted front view showing an example of a ship to which a microbubble ejection device according to the present invention is applied.

FIG. 2 is a partially omitted perspective view showing an embodiment of a micro-bubble ejection device according to the present invention.

FIG. 3 is a front sectional view together with a block diagram showing an example of a bubble-water mixed fluid generating means applied to the microbubble ejection device according to the present invention.

[Explanation of symbols]

 A jetting device (microbubble jetting device) E Friction reduction target range (blowing region) Y Friction-reducing vehicle 1 Hull 2 Bubble water mixed fluid generating means 3 Fluid jet 4 Submerged surface (hull surface) 7 Air intake 8 Water Suction Port 10 Flow Path Constituent 11 Fluid Transfer Pipe 12 Pyramidal Section 13 Diffusion Part 17 Gas Chamber S1 Cross Section of Fluid Transfer Pipe S2 Cross Section of Pyramid Connection with Fluid Transfer Pipe S3 Diffusion of Pyramidal Section Cross-sectional area of the connecting part with the part S4 Cross-sectional area in the middle of the diffusion part S5 Opening area of the fluid ejection port

 ─────────────────────────────────────────────────── ─── 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 (2)

[Claims] 1. A device (A) for ejecting a bubbling water mixed fluid.
A flow path forming body (10) for transferring the bubbly water mixed fluid, and a slit-shaped fluid ejection port (3) arranged in the flow path forming body for ejecting the bubbly water mixed fluid. However, the flow path structure is a fluid transfer pipe (1
1), a pyramid portion (12) connected to the tip of the fluid transfer pipe and having a flow passage cross-sectional shape deformed from a circular shape to a square shape, and a flow passage cross-sectional shape connected to the pyramidal portion and having a flow passage cross-sectional shape gradually increasing from a slit And a diffusion part (13) in a deformed state. 2. The microbubble ejection device according to claim 1, wherein a cross-sectional area in the middle of the diffusion portion (13) is set to be equal to or larger than that of the fluid ejection port (3).