Microbubble generator

Abstract

To provide a microbubble generator capable of ensuring sufficient pressure and flow rate even in high-speed or high-pressure liquid environments. [Solution] When the bubble generator 20 moves to a predetermined position in the liquid flow direction against the springs 21 and 22 due to the pressure of the liquid, it is equipped with second liquid flow passages 14 and 15 that connect the upstream and downstream sides of the bubble generator 20. Therefore, when a high-speed and high-pressure liquid flows into the device body 10, the bubble generator 20 moves and the second liquid flow passage 14 (or 15) communicates with the first liquid flow passage 13. This allows a portion of the liquid on the upstream side of the bubble generator 20 to flow through the second liquid flow passage 14 (or 15) and out to the downstream side of the bubble generator 20, ensuring sufficient pressure and flow rate even in high-speed or high-pressure liquid ranges.

Description

Technical Field

[0006]

[0001] The present invention relates to a microbubble generator that generates fine bubbles in a liquid flowing through a flow path such as tap water or industrial water.

Background Art

[0002] In recent years, as bubbles contained in a liquid, fine bubbles called so-called microbubbles and nanobubbles have attracted attention, and their practical applications in various fields such as various cleaning, purification, fisheries, agriculture, medicine, beauty, and food processing have been promoted. For example, in industrial applications, it is used for cleaning precision machine parts, preventing adhesion of foreign substances in pipes, improving water quality such as tap water and lakes, and preventing strange odors. Also, in the beauty and health fields, it is known to be effective for warm baths, skin cleaning, etc.

[0003] Generally, microbubbles refer to bubbles with a diameter of 1 μm or more and 100 μm or less, and nanobubbles refer to bubbles with a diameter of less than 1 μm. In particular, since nanobubbles are extremely small, they hardly float and remain in the liquid for a long time (several weeks to several months), so higher effects in their fields of use are expected.

[0004] As a device for generating such fine bubbles, there is known a device in which gas is introduced from the outside into a liquid flow portion provided in a flow path and mixed with the liquid flowing through the flow path to generate fine bubbles in the liquid (see, for example, Patent Documents 1, 2, or 3).

[0005] However, in a device in which gas is introduced from the outside into a liquid, there are problems that equipment such as a compressor for supplying gas is required and the structure becomes complicated. Also, when gas is introduced from the outside into a liquid, generally, the pressure of the liquid needs to be lower than the pressure of the gas, so there is also a problem that it is difficult to generate under a high liquid pressure due to the pressure limit of the introduced gas.

[0006] Therefore, a microbubble generator that solves these problems is known that generates microbubbles in the liquid flowing through the channel by the cavitation effect, thereby generating microbubbles in the liquid without introducing gas from the outside (see, for example, Patent Document 4 or 5). [Prior art documents] [Patent Documents]

[0007] [Patent Document 1] Japanese Patent Publication No. 2008-119623 [Patent Document 2] Japanese Patent Publication No. 2008-229516 [Patent Document 3] Japanese Patent Publication No. 2014-121689 [Patent Document 4] Patent No. 7142386 [Patent Document 5] Patent No. 6762461 [Overview of the Initiative] [Problems that the invention aims to solve]

[0008] Incidentally, in conventional cavitation-type microbubble generators, in order to compensate for the insufficient bubble generation in the low-speed or low-pressure range of the liquid, it is necessary to increase the pressure-receiving area of ​​the main component of the generator (hereinafter referred to as the core) and increase the flow rate of the liquid passing through the generator. However, increasing the pressure-receiving area of ​​the core increases the flow resistance in the high-speed or high-pressure range of the liquid, resulting in pressure loss and insufficient flow rate in the liquid flow path. Therefore, there has been a challenge in ensuring sufficient pressure and flow rate to accommodate large-flow equipment.

[0009] The present invention has been made in view of the above-mentioned problems, and its object is to provide a microbubble generator that can ensure sufficient pressure and flow rate even in high-speed or high-pressure liquid regions. [Means for solving the problem]

[0010] To achieve the above objective, the present invention provides a microbubble generating device installed in a liquid flow path and generating bubbles in the liquid flowing through the path, comprising: a first liquid flow path provided in the main body of the device; a bubble generating body provided in the first liquid flow path so as to be movable in the direction of liquid flow and generating microbubbles in the liquid flowing through the first liquid flow path by cavitation effect; a biasing member that biases the bubble generating body toward the opposite side of the liquid flow direction; and a second liquid flow path that connects the upstream and downstream sides of the bubble generating body when the bubble generating body moves to a predetermined position in the direction of liquid flow against the biasing member due to the pressure of the liquid.

[0011] As a result, bubbles are generated in the liquid flowing through the bubble generator by the bubble generator, and when a high-speed, high-pressure liquid flows into the main body of the device, the bubble generator moves, and the second liquid flow passage connects with the first liquid flow passage 13. A portion of the liquid upstream of the bubble generator flows through the second liquid flow passage and flows out to the downstream side of the bubble generator, thus ensuring sufficient pressure and flow rate even in high-speed or high-pressure liquid regions. [Effects of the Invention]

[0012] According to the present invention, sufficient pressure and flow rate can be secured even in high-speed or high-pressure liquid regions, so that a sufficient supply of liquid can always be provided to the downstream side of the pipeline, which is extremely advantageous for practical application. [Brief explanation of the drawing]

[0013] [Figure 1] Side cross-sectional view of a microbubble generating apparatus showing the first embodiment of the present invention [Figure 2] Front view of the microbubble generator [Figure 3] Cross-sectional view in the direction of arrow AA [Figure 4] Side cross-sectional view showing the operation of the microbubble generator. [Figure 5] Side cross-sectional view showing other operations of the microbubble generator. [Figure 6] Side cross-sectional view of a microbubble generator showing a second embodiment of the present invention. [Figure 7] Side cross-sectional view of the microbubble generator [Figure 8] Front view of the microbubble generator [Figure 9] Front cross-sectional view of the flow path member [Figure 10] Cross-sectional view taken in the direction of arrow B-B [Figure 11] Cross-sectional view taken in the direction of arrow C-C [Figure 12] Side cross-sectional view showing the operation of the microbubble generator [Figure 13] Enlarged side cross-sectional view of the main part showing the operation of the microbubble generator [Figure 14] Side cross-sectional view showing another operation of the microbubble generator

Embodiment for Carrying Out the Invention

[0014] Figs. 1 to 5 show the first embodiment of the present invention, and show a microbubble generator for generating fine bubbles in a liquid flowing through a flow path.

[0015] The microbubble generator of the present embodiment includes a device main body 10 through which a liquid flows inside, and a bubble generator 20 that generates fine bubbles in the liquid flowing through the device main body 10 by a cavitation effect. <0000​​​​​​Furthermore, each case body 11, 12 is provided with second liquid flow passages 14, 15, respectively, which connect the axial center side of the first liquid flow passage 13 to the connection ports 11a, 12a. One of the second liquid flow passages 14 is formed to extend axially within one case body 11, and one end of it opens into the connection port 11a. The other end of the one second liquid flow passage 14 opens into the end face of one case body 11 that abuts the other case body 12 in the axial direction, and the end face of the other case body 12 is provided with a notch 12b that connects the other end of the second liquid flow passage 14 to the inner circumferential surface of the first liquid flow passage 13.

[0018] The other second liquid passage 15 is formed to extend axially within the other case body 12, with one end opening into the connection port 12a. The other end of the other second liquid passage 15 opens into the end face of the other case body 12 where it abuts axially against the first case body 11, and the end face of the first case body 11 is provided with a notch 11b that connects the other end of the second liquid passage 15 to the inner circumferential surface of the first liquid passage 13.

[0019] Although a detailed illustration of the internal structure of the bubble generator 20 is omitted, it is configured to generate fine bubbles in the liquid by rapidly increasing the flow velocity and pressure by circulating the liquid through minute gaps, and then causing cavitation due to the depressurization effect when the liquid flows out of the gaps. For example, the structure described in Patent Document 4 or 5 can be used.

[0020] The bubble generator 20 is formed in a cylindrical shape having an outer diameter equal to the inner diameter of the first liquid passage 13, and is provided so as to be movable within the first liquid passage 13 toward one end and the other end of the first liquid passage 13 while sliding its outer circumferential surface toward the inner circumferential surface of the first liquid passage 13.

[0021] In this case, the bubble generator 20 is positioned on the axial center side of the first liquid flow passage 13, and springs 21 and 22 are provided on both sides of the bubble generator 20 as biasing means to bias the bubble generator 20 in the axial direction. As a result, the bubble generator 20 is pressed from both sides in the axial direction by the springs 21 and 22 and held on the axial center side (neutral position) of the first liquid flow passage 13. The notches 11b and 12b of each case body 11 and 12 are closed by the outer circumferential surface of the bubble generator 20 located on the axial center side, and when the bubble generator 20 moves in one axial direction (liquid flow direction) and the notch 12b of the other case body 12 is opened into the first liquid flow passage 13, the first liquid flow passage 13 and one of the second liquid flow passages 14 are connected via the notch 12b. Furthermore, when the bubble generator 20 moves axially to the other side (opposite to the liquid flow direction) and the notch 11b of one of the case bodies 11 is opened into the first liquid flow passage 13, the first liquid flow passage 13 and the other second liquid flow passage 15 are connected via the notch 11b.

[0022] In the microbubble generating device 1 configured as described above, as shown in Figure 1, when liquid flows into the device body 10 from one axial end, the liquid flows into the first liquid flow passage 13 and flows through the bubble generating body 20. At this time, bubbles are generated in the liquid passing through the bubble generating body 20, and the liquid containing the bubbles flows out from the other axial end of the device body 10.

[0023] In the bubble generator 20, the liquid flows through minute gaps, causing pressure loss due to the flow resistance of the bubble generator 20, which reduces the flow rate of the liquid downstream of the bubble generator 20. When the flow rate of the liquid supply is increased to introduce a high-speed, high-pressure liquid into the device body 10, the pressure of the liquid upstream of the bubble generator 20 increases, causing the bubble generator 20 to move in the liquid flow direction against the biasing force of one of the springs 21, as shown in Figure 4. As a result, the first liquid flow passage 13 upstream of the bubble generator 20 and the second liquid flow passage 14 communicate with each other, and a portion of the liquid upstream of the bubble generator 20 flows through the second liquid flow passage 14 and flows out to the downstream side of the bubble generator 20. This ensures that the flow rate of liquid flowing out of the device body 10 is sufficient, even in high-speed or high-pressure liquid ranges.

[0024] Furthermore, in this embodiment, liquid can also be circulated through the device body 10 in the opposite direction to the flow direction. That is, as shown in Figure 5, when liquid is introduced into the device body 10 from the other axial end, bubbles are generated in the liquid passing through the bubble generator 20 by the bubble generator 20, as described above, and the liquid containing the bubbles flows out from the one axial end of the device body 10.

[0025] In this case, as described above, if the flow rate of the liquid supply source is increased and a high-speed, high-pressure liquid flows into the device body 10, the pressure of the liquid upstream of the bubble generator 20 increases, and as shown in Figure 5, the bubble generator 20 moves in the liquid flow direction against the biasing force of the other spring 22. As a result, the first liquid flow passage 13 upstream of the bubble generator 20 and the other second liquid flow passage 15 communicate with each other, and a portion of the liquid upstream of the bubble generator 20 flows through the second liquid flow passage 15 and flows out to the downstream side of the bubble generator 20, ensuring a sufficient flow rate of liquid flowing out of the device body 10.

[0026] As described above, the microbubble generating device of this embodiment includes a first liquid flow passage 13 provided in the device body 10, a bubble generating body 20 provided in the first liquid flow passage 13 so as to be movable in the direction of liquid flow and generating microbubbles in the liquid flowing through the first liquid flow passage 13 by cavitation effect, springs 21 and 22 that bias the bubble generating body 20 in the opposite direction to the direction of liquid flow, and when the bubble generating body 20 moves to a predetermined position in the direction of liquid flow against the springs 21 and 22 due to the pressure of the liquid, the bubbles are generated Since the device is equipped with second liquid flow passages 14 and 15 that connect the upstream and downstream sides of the living organism 20, when a high-speed and high-pressure liquid flows into the main body 10 of the device, the bubble generator 20 moves and the second liquid flow passage 14 (or 15) connects with the first liquid flow passage 13. This allows a portion of the liquid upstream of the bubble generator 20 to flow through the second liquid flow passage 14 (or 15) and out to the downstream side of the bubble generator 20, ensuring sufficient pressure and flow rate even in high-speed or high-pressure liquid ranges. As a result, a sufficient supply of liquid can always be provided to the downstream side of the pipeline, which is extremely advantageous for practical application.

[0027] In this case, the outer circumferential surface of the bubble generator 20, located on the axial center side, closes the communication portion between the first liquid flow passage 13 and the second liquid flow passages 14 and 15. When the bubble generator 20 moves to a predetermined position in one axial direction, the communication portion is opened. This allows the bubble generator 20 to function as a valve body for opening and closing the second liquid flow passages 14 and 15. As a result, there is no need to provide a separate relief valve for opening and closing the second liquid flow passages 14 and 15, and the structure can be simplified.

[0028] Furthermore, the bubble generator 20 is provided so as to be movable from a position that closes the communication portion toward one end and the other end of the first liquid passage 13, and when it moves toward one end of the first liquid passage 13 to a predetermined position it opens the communication portion, and when it moves toward the other predetermined position toward the other end of the first liquid passage 13 it opens the communication portion. This allows liquid to flow through the device body 10 from any axial direction, and has the advantage of not requiring the work of checking the orientation of the device body 10 when connecting the microbubble generator 1 to the piping.

[0029] Figures 6 to 14 show a second embodiment of the present invention, which illustrates a microbubble generating device equipped with multiple bubble generators.

[0030] The microbubble generator of this embodiment comprises a device body 30 through which liquid flows, and three bubble generators 40 that generate microbubbles in the liquid flowing inside the device body 10 by cavitation effect.

[0031] The device body 30 consists of a cylindrical outer case body 31, a first inner case body 32 positioned at one axial end of the outer case body 31, a second inner case body 33 positioned at the other axial end of the first inner case body 32, and a flow path member 34 positioned in the axial center of the device body 30. A connection port 31a is provided at the other axial end of the outer case body 31 to which a pipe or other conduit (not shown) is connected, and three flow paths 31b are provided in parallel inside the connection port 31a. In this case, each flow path 31b is formed to extend radially diagonally outward from the other axial end of the device body 30 toward the center.

[0032] The first inner case body 32 has a connection port 32a to which a pipe or other conduit (not shown) is connected, and its outer surface is screwed onto the inner surface on one axial end of the outer case body 31. The second inner case body 33 is positioned between the first inner case body 32 and the flow path member 34, and has three flow paths 33a arranged in parallel with each other. In this case, each flow path 33a is formed to extend radially diagonally outward from one axial end of the device body 30 toward the center.

[0033] Within the flow channel member 34, three first liquid flow passages 35 for the flow of liquid are provided in parallel to each other, and the axial ends of each first liquid flow passage 35 communicate with the respective flow passages 31b and 33a. In this case, each first liquid flow passage 35 is formed in a cylindrical shape with an inner diameter that extends uniformly in the axial direction (liquid flow direction) of its inner circumferential surface, and as shown in Figure 9, a portion of the radial direction is formed to communicate with each other at the radial center of the flow channel member 34. In addition, the outer case body 31 is provided with a second liquid flow passage 36 that connects the axial center of each first liquid flow passage 35 to the respective flow passages 31b and 33a.

[0034] The second liquid flow passage 36 is formed in the gap between the inner circumferential surface of the outer case body 31 and the outer circumferential surface of the flow channel member 34, and both of its axial ends are in communication with the respective flow passages 31b and 33a via the axial end faces of the flow channel member 34 and the inner surface of the outer case body 31. The circumferential surface of the flow channel member 34 is provided with three openings 34a that connect each of the first liquid flow passages 35 and the second liquid flow passage 36, and the openings 34a are arranged at equal intervals in the circumferential direction relative to each other on the axial center side of the flow channel member 34.

[0035] Furthermore, a pair of flow restriction members 37 are provided at both axial ends of the second liquid flow passage 36 to restrict the flow of liquid in only one direction. Each flow restriction member 37 consists of a ring-shaped member extending in the circumferential direction of the flow channel member 34 and is positioned in the portion between the outer circumferential surface and the axial end surface (the chamfered portion) of the flow channel member 34. In this case, the flow restriction members 37 are provided within the second liquid flow passage 36 so as to be movable in the axial direction of the flow channel member 34. When liquid flows from the second liquid flow passage 36 to the flow channel 31b (or 33a) side, the flow restriction members 37 allow the flow of liquid by separating from the outer circumferential surface of the flow channel member 34 due to the pressure of the liquid. When liquid flows from the flow channel 31b (or 33a) side to the second liquid flow passage 36, the flow restriction members restrict the flow of liquid by closing the space between the outer circumferential surface of the flow channel member 34 and the inner circumferential surface of the second liquid flow passage 36 due to the pressure of the liquid.

[0036] Although a detailed illustration of the internal structure of each bubble generator 40 is omitted, similar to the first embodiment, it is configured to generate fine bubbles in the liquid by circulating the liquid through a minute gap to rapidly increase the flow velocity and pressure, and then causing cavitation due to the depressurization effect when the liquid flows out of the gap. For example, the structure described in Patent Document 4 or 5 can be used.

[0037] Furthermore, the bubble generator 40 is formed in a cylindrical shape having an outer diameter equal to the inner diameter of the first liquid flow passage 35, and is provided so as to be movable axially (in the direction of liquid flow) within the first liquid flow passage 35 toward one end and the other end of the first liquid flow passage 35, with its outer circumferential surface sliding against the inner circumferential surface of the first liquid flow passage 35. The bubble generator 40 is positioned on the axial center side of the first liquid flow passage 35, and springs 41 and 42 are provided on both sides of its axial direction as biasing means to bias the bubble generator 40 in the axial direction. As a result, the bubble generator 40 is pressed from both sides in the axial direction by the springs 41 and 42 and is held on the axial center side (neutral position) of the first liquid flow passage 35. In this case, springs 41 and 42 of each bubble generator 40 are used, and springs with different biasing forces (spring constants) are used.

[0038] Furthermore, the flow channel member 34 is supported at its radial center by a support shaft 38 extending in the axial direction, thereby creating a gap between the inner circumferential surface of the outer case body 31 and the outer circumferential surface of the flow channel member 34 that forms a second liquid flow passage 36. In this case, as shown in Figures 10 and 11, each bubble generator 40 within the flow channel member 34 is arranged so that its outer circumferential surfaces are in contact with each other, and the support shaft 38 is fixed at both ends to the outer case body 31 and the second inner case body 33, in contact with the outer circumferential surface of each bubble generator 40, so as to pass between each bubble generator 40.

[0039] Furthermore, each opening 34a of the flow channel member 34 is closed by the outer surface of each bubble generator 40 located on the axial center side of the first liquid flow passage 35. When the bubble generator 40 moves axially in one direction (liquid flow direction) or the other direction (opposite to the liquid flow direction) and the opening 34a is opened into the second liquid flow passage 36, the first liquid flow passage 35 and the second liquid flow passage 36 are connected through the opening 34a.

[0040] In the microbubble generating device 2 configured as described above, as shown in Figure 7, when liquid flows into the device body 30 from one axial end, the liquid is divided into each flow path 33a and flows into each first liquid flow passage 35, and circulates within each bubble generating body 40. At that time, bubbles are generated in the liquid passing through each bubble generating body 40 by each bubble generating body 40, and the liquid containing the bubbles flows out from the other axial end of the device body 30.

[0041] In each bubble generator 40, the liquid flows through minute gaps, causing pressure loss due to the flow resistance of each bubble generator 40, which reduces the flow rate of the liquid downstream of each bubble generator 40. When the flow rate of the liquid supply is increased to allow high-speed, high-pressure liquid to flow into the device body 30, the pressure of the liquid upstream of the bubble generator 40 increases, and as shown in Figure 12, the bubble generator 40 moves in the liquid flow direction against the biasing force of one of the springs 41, opening the opening 34a of the flow path member 34. As a result, the first liquid flow passage 35 and the second liquid flow passage 36 upstream of the bubble generator 40 come into contact. In this case, within the second liquid flow passage 36, the downstream flow restriction member 37 allows the flow of liquid in the liquid flow direction, while the upstream flow restriction member 37 restricts the flow of liquid in the opposite direction of the liquid flow. Specifically, on the upstream side of the second liquid flow passage 36, as shown in Figure 13, the flow restriction member 37 on the upstream side closes the second liquid flow passage 36 due to the pressure of the liquid flowing in from the flow path 33a side, and the flow of liquid attempting to flow back upstream through the second liquid flow passage 36 is blocked by the flow restriction member 37, so that the liquid flows through the second liquid flow passage 36 only in the same direction as the liquid flow direction of the first liquid flow passage 36.

[0042] As a result, a portion of the liquid upstream of the bubble generator 40 flows through the second liquid flow passage 36 and flows out to the downstream side of the bubble generator 40, ensuring a sufficient flow rate of liquid flowing out from the main body of the device 30.

[0043] In this case, if the opening and closing of the second liquid flow passage 36 occurs simultaneously due to the movement of each bubble generator 40, pulsation known as the hunting phenomenon is likely to occur. However, since springs 41 and 42 of each bubble generator 40 are used, springs with different biasing forces are not used, so the opening and closing of the second liquid flow passage 36 due to the movement of each bubble generator 40 does not occur simultaneously, and the occurrence of the hunting phenomenon is suppressed by the damping effect.

[0044] Furthermore, in this embodiment, liquid can also be circulated through the device body 30 in the opposite direction to the flow direction. That is, as shown in Figure 14, when liquid is introduced into the device body 30 from the other axial end, bubbles are generated by the bubble generators 40 in the liquid passing through each bubble generator 40, as described above, and the liquid containing the bubbles flows out from the one axial end of the device body 30.

[0045] As described above, the microbubble generating device of this embodiment includes a plurality of first liquid flow passages 25 provided within the device body 30, a plurality of bubble generating bodies 40 provided in each first liquid flow passage 35 so as to be movable in the direction of liquid flow and generating microbubbles in the liquid flowing through the first liquid flow passage 35 by cavitation effect, a plurality of springs 41, 42 that bias each bubble generating body 40 in the opposite direction to the direction of liquid flow, and each bubble generating body 40 is moved by the pressure of the liquid against the springs 41, 42 to a predetermined position in the direction of liquid flow. As the bubble generator 40 moves, it is equipped with a second liquid flow passage 36 that connects the upstream and downstream sides of the bubble generator 40. Therefore, similar to the first embodiment, when a high-speed and high-pressure liquid flows into the device body 30, each bubble generator 40 moves, and the second liquid flow passage 36 connects with the first liquid flow passage 35. This allows a portion of the liquid upstream of the bubble generator 40 to flow through the second liquid flow passage 36 and out to the downstream side of the bubble generator 40, ensuring sufficient pressure and flow rate even in high-speed or high-pressure liquid regions.

[0046] Furthermore, since the liquid is divided into multiple first liquid flow passages 35 arranged in parallel to each other, and bubbles can be generated in the liquid by multiple bubble generators 40 in each first liquid flow passage 35, a microbubble generator 2 can be configured to handle high-flow pipelines.

[0047] Furthermore, the outer circumferential surface of the bubble generator 40, located on the axial center side, closes the communication portion between the first liquid flow passage 35 and the second liquid flow passage 36. When the bubble generator 40 moves to a predetermined position in the axial direction, the communication portion is opened. This allows the bubble generator 40 to function as a valve body for opening and closing the second liquid flow passage 36. As a result, there is no need to provide a separate relief valve for opening and closing the second liquid flow passage 36, and the structure can be simplified.

[0048] Furthermore, each bubble generator 40 is provided so as to be movable from a position that closes the communication portion toward one end and the other end of the first liquid flow passage 35, and is provided so as to open the communication portion when it moves toward one end of the first liquid flow passage 35 to a predetermined position, and open the communication portion when it moves toward the other predetermined end of the first liquid flow passage 35 to another predetermined position, so that liquid can be flowed through the device body 30 from any direction in the axial direction, and there is an advantage that it is not necessary to check the orientation of the device body 30 when connecting the microbubble generator 2 to the piping.

[0049] Furthermore, the second liquid flow passage 36 is formed between the outer circumferential surface of the flow channel member 34 and the inner circumferential surface of the device body 30. A pair of flow restriction members 37 provided on both axial ends restrict the liquid flow direction of the second liquid flow passage 36 to the same direction as the liquid flow direction of the first liquid flow passage 35. This eliminates the need to provide multiple second liquid flow passages with different liquid flow directions, thus simplifying the structure.

[0050] Furthermore, since the springs 41 and 42 of each bubble generator 40 are configured to have different biasing forces, the opening and closing of the second liquid flow passage 36 due to the movement of each bubble generator 40 does not occur simultaneously, and the resulting damping effect can suppress the occurrence of the hunting phenomenon. As a result, the liquid inside the main body 30 of the device can always be circulated smoothly.

[0051] In the second embodiment described above, a configuration with three bubble generators 40 was shown, but a configuration with two or four or more bubble generators may also be used.

[0052] Furthermore, the above embodiments are examples of the present invention, and the present invention is not limited to those described in the above embodiments. [Explanation of Symbols]

[0053] 1,2...Microbubble generator, 10...Device body, 13...First liquid flow passage, 14,15...First liquid flow passage, 30...Device body, 35...First liquid flow passage, 36...First liquid flow passage, 37...Flow restriction member, 40...Bubble generator, 41,42...Spring.

Claims

1. In a microbubble generating device installed in a flow path of liquid and which generates bubbles in the liquid flowing through the flow path, A first liquid flow passage provided inside the main body of the device, A bubble generator is provided in the first liquid flow passage so as to be movable in the direction of liquid flow, and generates fine bubbles in the liquid flowing through the first liquid flow passage by cavitation effect, A biasing member that biases the bubble generator toward the opposite direction of liquid flow, When the bubble generator moves to a predetermined position in the liquid flow direction against a biasing member due to the liquid pressure, it is equipped with a second liquid flow passage that connects the upstream and downstream sides of the bubble generator. A microbubble generating device characterized by the following features.

2. The bubble generator is designed to close the communication portion between the first liquid flow passage and the second liquid flow passage, and to open the communication portion when it moves to a predetermined position. The microbubble generating apparatus according to feature 1.

3. The bubble generator is provided so as to be movable from a position that closes the communication portion toward one end and the other end of the first liquid flow passage, and is provided so as to open the communication portion when it moves toward one end of the first liquid flow passage to a predetermined position, and to open the communication portion when it moves toward the other predetermined position toward the other end of the first liquid flow passage. The microbubble generating apparatus according to feature 2.

4. The main body of the apparatus is provided with a plurality of first liquid flow passages arranged in parallel, through which the liquid is divided, and a plurality of bubble generators and biasing members are provided in each of the first liquid flow passages. The microbubble generating apparatus according to feature 1.

5. The biasing members of each of the aforementioned bubble generators are configured to have different biasing forces from one another. The microbubble generating apparatus according to feature 4.

Images