Fine bubble generator

Abstract

To provide a fine bubble generator with a simple structure and sufficient durability. [Solution] The bubble generating section 11 has an inlet section 2 located on the upstream side, a diffusion section 3 having a bottom section 31 on the inside, and a conical section 4. The inlet section 2 has an outer peripheral section 21 on the radially outer side and a plurality of blades 23, with a cavity 22 formed in the center. The base end 23a of the blades 23 is connected to the outer peripheral section 21, and the tip 23b is arranged to surround the outside of the cavity 22. Each blade 23 is arranged at an equal angle and spacing around the central axis, and a curved channel 24 of the same shape is formed between each blade 23. The bottom of the diffusion section 3 is inclined downstream so that the distance from the inlet section 2 gradually increases from the radially inner side to the radially outer side, and a radial opening 32 is formed on the outer peripheral surface of the diffusion section 3 that opens radially outward.

Description

Technical Field

[0001] The present invention relates to an apparatus for generating fine bubbles in a liquid.

Background Art

[0002] In recent years, in anticipation of improvements in cleaning effects and other effects, research has been underway on techniques for generating a large amount of fine bubbles such as fine bubbles in water (or other liquids). Currently, various types of fine bubble generators are manufactured and supplied to the market.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] Conventional fine bubble generators have a complex structure for generating fine bubbles, and many have a large number of small protrusions and blades formed with sharp or thin parts at their tips. However, those with a complex structure are difficult to manufacture, and there is a problem that it is difficult to obtain sufficient durability when forming sharp or thin parts with plastic.

[0005] The present invention aims to solve such problems in the prior art and provide a fine bubble generator with a simple structure and sufficient durability.

Means for Solving the Problems

[0006] The fine bubble generator according to the present invention comprises a bubble generating section and a holder that houses it, the holder having an upstream section and a downstream section, an upstream channel formed in the upstream section of the holder, and a downstream channel formed on the inside of the downstream section, the bubble generating section having an inlet section located on the upstream side, a diffusion section having a bottom on the inside, and a conical section, the inlet section being formed in an annular shape and having an outer peripheral section radially outward and a plurality of blades, with a cavity formed in the center, the outer peripheral section of the inlet section having a larger radius than the diffusion section and having a configuration that is continuous in an annular shape in the circumferential direction, the base end of the blades being connected to the outer peripheral section and the tip end The structure is characterized by being arranged to surround the outside of the cavity, curving from the radially inward to the radially outward such that the angle with respect to the tangent gradually decreases, extending axially from the outer end face of the inlet section, with its downstream end connected to the bottom of the diffusion section, each blade being arranged at equal angles and spacings around the central axis of the bubble generation section, forming curved channels of the same shape between each blade, the bottom of the diffusion section being inclined downstream so that the distance from the inlet section gradually increases from the radially inward to the radially outward side, and a radial opening being formed on the outer circumferential surface of the diffusion section that opens radially outward at the end of the curved channel.

[0007] In this fine bubble generator 1, it is preferable that an axial channel is formed between the base ends of each blade of the inlet section, which linearly communicates from the outer end face to the radially outer region of the diffusion section, and that an axial opening is formed on the diffusion section side surface of the inlet section, which opens toward the axial direction of the bubble generator section, at a position outside the radial opening of the diffusion section.

[0008] Furthermore, it is preferable that the inclination angle of the bottom with respect to a plane perpendicular to the central axis of the bubble generation section is set within the range of 10 to 20°. In addition, it is preferable that the downstream flow path of the holder has a large-diameter section having a large diameter capable of accommodating the diffusion section and conical section of the bubble generation section, a constricted section downstream of the large-diameter section where the cross-sectional area gradually decreases, a small-diameter section with the smallest cross-sectional area, and an expanding section downstream of the small-diameter section where the cross-sectional area gradually increases.

[0009] Furthermore, it is preferable that the bubble generating section is positioned inside the large-diameter section on the downstream side of the holder, and that the upstream and downstream sections are connected so that the inlet section is sandwiched between them, and the bubble generating section is held within the holder. Moreover, it is preferable that an outside air intake passage is formed on the downstream side of the holder, with one end opening at the small-diameter section. [Effects of the Invention]

[0010] The fine bubble generator according to the present invention, by rationally combining and arranging the elements for generating fine bubbles, has a simple structure that can generate a sufficient amount of fine bubbles, and has very few sharp or thin parts, so sufficient durability can be expected, making it an extremely practical fine bubble generator. [Brief explanation of the drawing]

[0011] [Figure 1] Figure 1 is a cross-sectional view of the fine bubble generator 1 according to the present invention. [Figure 2] Figure 2 is a perspective view of the bubble generation unit 11 shown in Figure 1. [Figure 3] Figure 3 is a cross-sectional perspective view of the bubble generation section 11 shown in Figure 2 (a view showing the state with the inlet section 2 removed). [Figure 4] Figure 4 shows the top view, bottom view, and side view of the bubble generation unit 11 shown in Figure 2. [Modes for carrying out the invention]

[0012] Hereinafter, an embodiment of the "fine bubble generator" according to the present invention will be described with reference to the attached drawings. Figure 1 is a cross-sectional view of the fine bubble generator 1 according to the present invention. As shown in the figure, the fine bubble generator 1 consists of a bubble generation unit 11 and a holder 12 that houses it. The bubble generation unit 11 consists of a disc-shaped inlet unit 2, a diffusion unit 3, and a conical unit 4 located on the upstream side, and the holder 12 consists of an upstream side unit 5 and a downstream side unit 6.

[0013] An upstream channel 51 is formed inside the upstream portion 5 of the holder 12, and a downstream channel is formed inside the downstream portion 6. The downstream channel consists of a large-diameter section 61 having a large diameter capable of accommodating the diffusion portion 3 and conical portion 4 of the bubble generation portion 11, a constricted section 62 downstream of the large-diameter section 61 where the cross-sectional area gradually decreases, a small-diameter section 63 with the smallest cross-sectional area, and an expanding-diameter section 64 downstream of the small-diameter section 63 where the cross-sectional area gradually increases. An outside air intake passage 65 is formed in the downstream portion 6, with one end opening at the small-diameter section 63.

[0014] In this fine bubble generator 1, as shown in Figure 1, the bubble generating unit 11 is positioned inside the large-diameter portion 61 of the downstream portion 6, and when the upstream portion 5 and the downstream portion 6 are connected, the inlet portion 2 is sandwiched between them, and the bubble generating unit 11 is held within the holder 12.

[0015] Figure 2 is a perspective view of the bubble generating unit 11 shown in Figure 1. As shown, the inlet portion 2 of the bubble generating unit 11 is formed in a disc shape (annular) and has an outer peripheral portion 21 arranged radially outward and a plurality of blades 23 (eight in this embodiment (four or more is preferable)). The center of the inlet portion 2 is empty and is hollow (hollow portion 22).

[0016] The outer periphery 21 of the inlet section 2 has a larger radius than the diffusion section 3 and is configured to be continuous in an annular shape in the circumferential direction. The blades 23 have a base end 23a connected to the outer periphery 21, and a tip 23b positioned to surround the outside of the cavity 22, extending roughly radially from the base end 23a to the tip 23b. The blades 23 also extend axially from the outer end face of the inlet section 2 (the upper surface of the bubble generating section 11 shown on the left side of Figure 2, the side opposite to the diffusion section 3) and are configured to reach the inside of the diffusion section 3.

[0017] Furthermore, the blades 23 are curved such that the angle with respect to the radial direction of the inlet section 2 is larger at the radially outer portion (base end 23a side) than at the radially inner portion (tip end 23b side), that is, the angle with respect to the tangent to the diffusion section 3 etc. gradually decreases from the radially inner to the radially outer portion. Furthermore, all eight blades 23 have the same shape and are arranged at equal angles and intervals around the central axis of the bubble generation section 11. As a result, gaps of the same shape (curved flow channels 24) are formed between each blade 23.

[0018] Furthermore, the inlet section 2 has a flow path (axial flow path 25) that communicates linearly (in a direction parallel to the central axis direction of the inlet section 2) from the outer end face (the upper surface of the bubble generation section 11 shown on the left side of Figure 2, the surface opposite to the diffusion section 3) to the radially outer region of the diffusion section 3. There are eight of these axial flow paths 25, one at each position between the base ends 23a of the eight blades 23, and an axial opening 26 is formed on the lower surface of the inlet section 2 (the surface on the diffusion section 3 side) that opens toward the axial direction of the bubble generation section 11.

[0019] FIG. 3 is a cross-sectional perspective view showing a state in which the inlet portion 2, that is, a part of the outer peripheral portion 21 and the blades 23 (a portion radially inward of the outer peripheral portion 21), is removed from the bubble generation portion 11 shown in FIG. 2. As shown in FIGS. 2 and 3, radial openings 32 that open radially outward are formed on the outer peripheral surface of the diffusion portion 3. These radial openings 32 are formed one by one (a total of eight) at the end portions (radially outward) of the eight curved flow paths 24. In addition, as shown in FIG. 2, the axial opening 26 of the axial flow path 25 is formed at a position outside the radial opening 32 of the diffusion portion 3.

[0020] As shown in FIG. 3, a bottom portion 31 is formed inside the diffusion portion 3. This bottom portion 31 has a mound shape and is inclined downstream such that the distance from the inlet portion 2 gradually increases from the radially inner side to the outer side (see FIG. 1). In the present embodiment, the inclination angle of the bottom portion 31 (the angle with respect to the plane orthogonal to the central axis of the bubble generation portion 11) is set to 15° (preferably set to 10 to 20°). Further, as described above, the blades 23 extend from a position inside the inlet portion 2 to the inside of the diffusion portion 3, and the downstream end portion is connected to the bottom portion 31 of the diffusion portion 3 (see FIG. 3).

[0021] When a pipe or a hose is connected to the upstream side portion 5 of the holder 12 shown in FIG. 1 and water (or other liquid) is supplied into the holder 12, fine bubbles are generated in the holder 12. Hereinafter, this point will be described in detail. In the fine bubble generator 1 of the present embodiment, when the bubble generation portion 11 is mounted in the holder 12, the outer peripheral portion 21 of the inlet portion 2 and the blades 23 (see FIG. 2) are configured to be covered by the upstream side portion 5, and the water supplied into the upstream side flow path 51 flows into the cavity portion 22 of the inlet portion 2 in a state where the cross-sectional area is reduced and the flow velocity and pressure are increased.

[0022] The water flowing into the cavity 22 collides with the bottom 31 of the diffusion part 3 (the central part 31a of the bottom 31 located on the downstream side of the cavity 22) (see FIG. 3), and diffuses radially outward therefrom. As described above, eight blades 23 (see FIGS. 2 and 3) are arranged so as to surround the outer periphery of the cavity 22 in the radially outer side thereof, and a curved flow path 24 is formed between them. Therefore, a part of the water flow that collides with the bottom 31 and diffuses around flows directly into the curved flow path 24, and another part of the water flow flows into the curved flow path 24 after colliding with the tip 23b of the blade 23.

[0023] Of the water flowing into the curved flow path 24, a part flows along the bottom 31 in the region within the diffusion part 3, and another part flows toward the outer peripheral part 21 in the region within the inlet part 2.

[0024] In the region within the diffusion part 3, the water flowing along the bottom 31 in the curved flow path 24 ejects radially outward from the diffusion part 3 through the radial opening 32 (see FIGS. 2 and 3) at the end of the flow path. As described above, the blade 23 is curved such that the angle with respect to the tangent line of the diffusion part 3 and the like gradually decreases from the radially inner side to the outer side, and the bottom 31 is inclined downstream from the radially inner side to the outer side. Therefore, the water flow ejected radially outward from the diffusion part 3 turns around the axis of the bubble generation part 11 at high speed and flows downstream in the inner side of the downstream part 6 (the region between the outer peripheral surface of the diffusion part 3 and the inner peripheral surface of the large-diameter part 61, and the region between the outer peripheral surface of the conical part 4 and the inner peripheral surface of the throttle part 62).

[0025] Meanwhile, water flowing through the curved channel 24 towards the outer periphery 21 in the region within the inlet section 2 collides with the inner circumferential surface of the outer periphery 21 (axial channel 25), changes direction from there toward the axial direction of the bubble generation section 11, and is ejected from the axial opening 26 formed on the lower side surface of the inlet section 2. At this time, as described above, the axial opening 26 is formed outside the radial opening 32 of the diffusion section 3 and opens toward the axial direction of the bubble generation section 11. Therefore, the water flow ejected axially from the axial opening 26 collides with the water flow ejected radially outward from the radial opening 32 of the diffusion section 3 and flows downstream.

[0026] Thus, in the fine bubble generator 1 of this embodiment, water (or other liquid) supplied to the upstream side 5 of the holder 12 flows into the bubble generation section 11 at high speed and pressure, colliding with the bottom 31 of the diffusion section 3, the tip 23b of the blades 23, the inner surface of the outer circumferential section 21, etc., and the water flows collide with each other on the radially outer side of the diffusion section 3, forming complex water flows inside and outside the diffusion section 3, and in doing so, a large amount of fine bubbles can be generated in the water.

[0027] The water flow containing fine bubbles is rectified in the region downstream of the diffusion section 3 (more specifically, the region between the inner surface of the constricted section 62 and the outer surface of the conical section 4), maintaining a swirling flow. As the cross-sectional area is reduced in the constricted section 62, the flow velocity increases. When the water passes through the small-diameter section 63, outside air is mixed in via the outside air introduction passage 65 due to the Venturi effect, and the water, now mixed with fine bubbles and larger bubbles, is sent further downstream from the widened-diameter section 64.

[0028] Conventional fine bubble generators have complex structures to generate fine bubbles, often featuring numerous blades with small protrusions or sharp or thin-walled tips. However, complex structures are difficult to manufacture, and forming the sharp or thin-walled parts with plastic makes it difficult to achieve sufficient durability. The fine bubble generator 1 according to the present invention, on the other hand, has a simple structure, making it easy to manufacture, and has very few sharp or thin-walled parts, thus providing sufficient durability. [Explanation of Symbols]

[0029] 1: Fine bubble generator, 11: Bubble generation section, 12: Holder, 2: Inlet section, 21: Outer periphery, 22: Cavity part, 23: Feathers, 23a: proximal end; 23b: tip, 24: Curved channel, 25: Axial flow path, 26: Axial opening, 3: Diffusion section, 31: Bottom, 31a: central part, 32: radial opening, 4: Conical section, 5: Upstream side, 51: Upstream flow path, 6: Downstream side, 61: Large diameter section, 62: Aperture section, 63: Small diameter part, 64: Expanded diameter part, 65: Outside air intake channel,

Claims

1. It has a bubble generating unit and a holder that houses it, The holder has an upstream side and a downstream side, An upstream channel is formed on the upstream side of the holder, and a downstream channel is formed on the inside of the downstream side. The bubble generation section has an inlet section located on the upstream side, a diffusion section with a bottom on the inside, and a conical section. The inlet section is formed in an annular shape, has an outer peripheral portion that is radially outward, and multiple blades, with a hollow section formed in the center. The outer periphery of the inlet section has a larger radius than the diffusion section and has a continuous ring-like structure in the circumferential direction. The blades are arranged such that their base ends are connected to the outer circumference and their tips surround the outside of the cavity, curving from the radially inward to the outward, with the angle with respect to the tangential gradually decreasing, and extending axially from the outer end face of the inlet, with their downstream ends connected to the bottom of the diffusion section. Each blade is arranged at equal angles and intervals around the central axis of the bubble generation section, and a curved channel of the same shape is formed between each blade. The bottom of the diffusion section slopes downstream so that the distance from the inlet section gradually increases from the radially inward to the outward side. A fine bubble generator characterized in that a radial opening is formed on the outer surface of the diffusion section, which opens radially outward at the end of the curved flow path.

2. The fine bubble generating apparatus according to claim 1, characterized in that an axial channel is formed between the base ends of each blade of the inlet section, which linearly communicates from the outer end face to the radially outer region of the diffusion section, and an axial opening is formed on the diffusion section side surface of the inlet section, which opens toward the axial direction of the bubble generating section, located outside the radial opening of the diffusion section.

3. The fine bubble generating apparatus according to claim 1 or claim 2, characterized in that the inclination angle of the bottom with respect to a plane perpendicular to the central axis of the bubble generating section is set within the range of 10 to 20°.

4. The fine bubble generator according to claim 1 or claim 2, characterized in that the downstream flow path of the holder has a large diameter section having a large diameter capable of accommodating the diffusion section and conical section of the bubble generation section, a constricted section downstream of the large diameter section in which the cross-sectional area gradually decreases, a small diameter section with the smallest cross-sectional area, and an expanding diameter section downstream of the small diameter section in which the cross-sectional area gradually increases.

5. The fine bubble generating device according to claim 4, characterized in that the bubble generating unit is positioned inside the large-diameter portion of the downstream side of the holder, and when the upstream and downstream sides are connected, the inlet portion is sandwiched between them, and the bubble generating unit is held within the holder.

6. The fine bubble generating device according to claim 1 or claim 2, characterized in that an outside air intake passage is formed on the downstream side of the holder, with one end opening at a small diameter portion.

Images