Fine air bubble generator

Abstract

To make it possible to adjust properties of fine air bubbles generated by a fine air bubble generator.SOLUTION: A fine air bubble generator comprises a casing 11 having a flow channel formation space C connecting an upstream side and a downstream side, and a piece component 30 provided in the casing 11, and generates fine air bubbles in a liquid by flow of the liquid between an internal surface of the flow channel formation space C and an external surface of the piece component 30. The fine air bubble generator comprises a position adjustment mechanism which adjusts positions of the casing 11 and the piece component 30 along a flow direction of the liquid.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to a micro-bubble generator for generating micro-bubbles in a liquid. [Background technology]

[0002] In recent years, there has been an increase in technologies that use microbubbles to purify water and promote the growth of organisms in aquaculture farms. Microbubbles are a collection of microscopic bubbles present in a liquid, and generally refer to bubbles with a diameter of 100 μm or less. Microbubbles are also classified according to their size. For example, bubbles with a diameter of 1 to 100 μm are called microbubbles, and even finer bubbles are called micro-nanobubbles or nanobubbles.

[0003] As a device for generating fine bubbles, for example, there are fine bubble generators described in Patent Documents 1 and 2. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] JP 2012-130901 A [Patent Document 2] JP 2017-225961 A Summary of the Invention [Problem to be solved by the invention]

[0005] In the micro-bubble generators of Patent Documents 1 and 2, the internal structure of the nozzle is made into a Venturi tube shape, and a core (flow dividing piece) is provided inside the casing to form a liquid containing micro-bubbles. However, the micro-bubble generators of Patent Documents 1 and 2 have a problem in that the properties of the generated micro-bubbles cannot be adjusted.

[0006] Therefore, an object of the present invention is to make it possible to adjust the properties of the fine bubbles generated by a fine bubble generator. [Means for solving the problem]

[0007] In order to solve the above problems, the present invention provides: a casing having a flow passage forming space connecting an upstream side and a downstream side; a support member provided inside the casing, A micro-bubble generator that generates micro-bubbles in a liquid by causing the liquid to flow between an inner surface of the flow passage forming space and an outer surface of the piece member, The fine bubble generating device is provided with a position adjustment mechanism for adjusting the positions of the casing and the top member (Configuration 1).

[0008] In an embodiment having configuration 1, A configuration can be adopted in which the positions of the casing and the piece members are adjusted along the flow direction of the liquid (configuration 2).

[0009] In an embodiment having configuration 2, an inner surface of the flow passage forming space includes a first tapered portion that narrows in diameter from the upstream side to the downstream side, and a second tapered portion that is provided downstream of the first tapered portion on the inner surface of the flow passage forming space and that widens in diameter from the upstream side to the downstream side, The piece member may have an upstream outer circumferential tapered portion that expands in diameter from the upstream side toward the downstream side, and may define a second flow passage between the piece member and the second tapered portion (Configuration 3).

[0010] In addition, in an embodiment having the configuration 2, The inner surface of the flow passage forming space includes a second tapered portion that expands in diameter from the upstream side toward the downstream side, The piece member may have an upstream outer circumferential tapered portion that expands in diameter from the upstream side toward the downstream side, and may define a second flow passage between the piece member and the second tapered portion (Configuration 4).

[0011] In an embodiment having configuration 4, The piece member may have a downstream end face at the downstream end of the upstream outer peripheral tapered portion, and the angle between the downstream end face and the generatrix of the upstream outer peripheral tapered portion may be an acute angle (configuration 5).

[0012] In an embodiment having configuration 5, The downstream end surface may be an inclined surface that approaches the upstream side as it moves away from the second tapered portion (Configuration 6).

[0013] In an embodiment having the configuration 1, or in an embodiment in which one or more elements selected from the configurations 2 to 6 are added to the configuration 1, The top member is provided at an upstream end of a longitudinal first member extending along the flow direction of the liquid, The position adjustment mechanism includes an adjustment member provided between the first member and the housing, or between the first member and a socket fixed to the housing, and the adjustment member can be configured to be screwed to the first member and the housing or the first member and the socket (configuration 7).

[0014] In addition, in an embodiment having the configuration 1, or an embodiment in which one or more elements selected from the configurations 2 to 7 are added to the configuration 1, The top member is provided at an upstream end of a first member having a longitudinal shape extending along a flow direction of the liquid, A second member is screwed to the first member so as to be freely advanced and retreated along its longitudinal direction downstream of the top member, and the second member can have a downstream outer peripheral tapered portion on its outer surface that expands in diameter from the upstream side toward the downstream side (configuration 8).

[0015] In an embodiment having configuration 8, The second member may be configured to be detachable from the first member (Configuration 9).

[0016] In addition, in an embodiment having the configuration 1, or an embodiment in which one or more elements selected from the configurations 2 to 9 are added to the configuration 1, The first member can have an intermediate outer peripheral tapered section downstream of the top member, the intermediate outer peripheral tapered section expanding in diameter from the upstream side toward the downstream side, and the intermediate outer peripheral tapered section forms a fourth flow path section between the second tapered section and the fourth flow path section, and a third flow path section is provided between the second flow path section and the fourth flow path section, the third flow path section having a larger cross-sectional area of ​​the flow path than the second flow path section and the fourth flow path section and generating negative pressure within the flow path (structure 10).

[0017] Also, a top member used in a fine-bubble generator having configuration 1 or having a single or multiple elements selected from configurations 2 to 10 added to configuration 1 can be adopted, the top member being connected to the casing via the position adjustment mechanism (configuration 11).

[0018] Furthermore, a first member having a top member used in the fine-bubble generator having the aspect of configuration 9, in which the second member is detachable, can be employed (configuration 12).

[0019] Furthermore, a fine bubble generator having the configuration 1 or a single or multiple elements selected from the configurations 2 to 10 are added to the configuration 1, A method of adjusting fine bubbles by adjusting the position of the piece member relative to the casing can be adopted (Configuration 13).

[0020] In addition, by using the fine bubble generator of the aspect having the configuration 9, A method for adjusting fine bubbles can be employed in which, after removing the second member from the first member, another second member having a shape different from that of the second member is attached to the first member (Configuration 14). Effect of the Invention

[0021] The present invention makes it possible to adjust the properties of the micro-bubbles generated by the micro-bubble generator. [Brief description of the drawings]

[0022] [Figure 1] FIG. 1 is a vertical cross-sectional view showing an embodiment of the present invention. [Diagram 2] FIG. [Diagram 3] Left side view of Figure 2 [Figure 4] Right side view of Figure 2 [Diagram 5] FIG. [Figure 6] FIG. [Figure 7] FIG. 11 is a vertical cross-sectional view showing a modified example of an embodiment. [Figure 8A] Vertical cross section of the casing [Figure 8B] Front view of the casing [Figure 8C] Right side view of Figure 8B [Figure 9A] FIG. 2 is a perspective view of the first member from the upstream side; [Figure 9B] FIG. 1 is a perspective view of a main portion of a first member from a downstream side; [Figure 10A] A side view of the second member [Figure 10B] A longitudinal sectional view of the second member [Figure 10C] FIG. 11 is a vertical cross-sectional view showing a modified example of the second member; [Figure 11A] Side view of the lock ring [Figure 11B] Vertical cross section of the lock ring [Figure 12A] Socket cross section [Figure 12B] Socket side view [Figure 13A] Side view of the adjustment member [Figure 13B] Front view of the adjustment member [Figure 13C] Vertical cross-sectional view of the adjustment member [Figure 14A] Vertical cross section of the base [Figure 14B] Side view of the pedestal [Figure 15] FIG. 11 is a vertical cross-sectional view showing another embodiment. [Figure 16] FIG. 11 is a vertical cross-sectional view showing yet another embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0023] An embodiment of the present invention will be described with reference to the drawings. The embodiment relates to a micro-bubble generator that generates micro-bubbles in a liquid. Micro-bubbles are a collection of bubbles with a minute diameter that are present in a liquid. In the embodiment, water is exemplified as the liquid, but the present invention can be applied to various liquids other than water.

[0024] As shown in Figs. 1 to 6, the micro-bubble generator 10 includes a casing 11 having therein a flow path forming space C connecting the upstream side and the downstream side, and a piece member 30 provided inside the casing 11. Micro-bubbles are generated in the water by water flowing between the inner surface of the flow path forming space C and the outer surface of the piece member 30. In addition, the positions of the casing 11 and the piece member 30 can be adjusted by a position adjustment mechanism, so that the properties of the micro-bubbles (diameter, number, etc. of the bubbles) can be adjusted by changing the positional relationship. Furthermore, the water spray pressure of the liquid containing the micro-bubbles can be adjusted.

[0025] The fine bubble generator 10 can be easily installed by connecting the casing 11 to the upstream flow path 1 (inlet pipe 1). By disposing the fine bubble generator 10 at the end of the flow path, water containing fine bubbles is sprayed into the air. The connection structure between the casing 11 and the upstream flow path 1 may be in the form of a press fit as shown in Fig. 1, or may employ a screw connection or other well-known structure.

[0026] In this embodiment, the casing 11 is cylindrical, and the flow passage forming space C is formed linearly along the axis of the casing 11. Therefore, the positions of the casing 11 and the piece member 30 are adjusted along the water flow direction.

[0027] As shown in FIG. 1 and FIG. 8A, the casing 11 includes a first tapered portion 12 that narrows from the upstream side to the downstream side along the water flow direction (hereinafter, also referred to as the axial direction of the flow path or simply the axial direction), and a second tapered portion 15 that expands from the upstream side to the downstream side. The second tapered portion 15 is provided downstream of the first tapered portion 12, and a ridge portion 18 that protrudes at an obtuse angle toward the inner diameter side (toward the axial center side of the flow path) is formed between the first tapered portion 12 and the second tapered portion 15. The ridge portion 18 is a smooth arc shape in any vertical cross section passing through the axial center. The first tapered portion 12, the ridge portion 18, and the second tapered portion 15 form the inner surface of the flow path forming space C. The axial ends of the flow path forming space C are a conical inner surface 16 that continues to the inner surface of the flow path space 3 of the upstream flow path 1, and a conical inner surface 72 that continues to the inner surface of the flow path space 4 of the downstream flow path. In the embodiment, the inner surface 16 is gradually diverging toward the upstream side, and the inner surface 72 is gradually diverging toward the downstream side, however, it is also contemplated that the inner surfaces 16, 17 may be cylindrical.

[0028] A piece member 30 is disposed within the flow passage forming space C. The piece member 30 is provided at the upstream end of a longitudinal first member 20 extending along the axial direction. The first member 20 has a cylindrical main body 25, and the main body 25 and the piece member 30 are connected by a connecting portion 35 provided on the piece member 30. The connecting portion 35 has a smaller diameter than the downstream end of the piece member 30 and the main body 25, and is disposed opposite only the second tapered portion 15 in the axial direction.

[0029] As shown in Fig. 9A, the piece member 30 is a cone-shaped member having an upstream outer peripheral tapered portion 31 on its outer surface, the diameter of which increases from the upstream side to the downstream side, and a downstream end face 33 that closes the bottom of the upstream outer peripheral tapered portion 31. The tip (upstream end) 32 of the upstream outer peripheral tapered portion 31 has a sharp shape. However, the shape of this tip 32 may be a smooth spherical shape. In this embodiment, the upstream outer peripheral tapered portion 31 is a conical surface (tapered surface) with a single gradient that continues from the tip 32 of the piece member 30 to the outer edge of the downstream end face 33, but this may be a conical surface with multiple gradients, or a circular arc surface that gradually widens toward the downstream side.

[0030] The upstream outer peripheral taper section 31 is disposed facing each other across the first taper section 12 and the second taper section 15. As a result, the upstream outer peripheral taper section 31 forms a first flow passage section 51 between itself and the first taper section 12, and a second flow passage section 52 between itself and the second taper section 15. Here, the first flow passage section 51 is configured such that the cross-sectional area of ​​the flow passage gradually decreases between the first taper section 12, which gradually decreases in diameter toward the downstream side in the axial direction, and the upstream outer peripheral taper section 31, which gradually increases in diameter toward the downstream side in the axial direction. In addition, the second flow passage section 52 is configured such that the cross-sectional area of ​​the flow passage gradually increases between the second taper section 15, which gradually increases in diameter toward the downstream side in the axial direction, and the upstream outer peripheral taper section 31, which gradually increases in diameter toward the downstream side in the axial direction. This is because the generatrix of the second taper section 15 and the generatrix of the upstream outer peripheral taper section 31 are parallel to each other, but the position of the space that constitutes the flow passage therebetween gradually moves toward the outer diameter side along the flow direction. In this way, by suddenly changing the cross-sectional area of ​​the flow path from the first flow path portion 51 to the second flow path portion 52, cavitation occurs, and the amount of fine bubbles generated can be increased.

[0031] The main body 25 of the first member 20 is provided with an intermediate outer peripheral tapered section 22, which expands in diameter from the upstream side toward the downstream side, downstream of the connecting section 35 of the piece member 30. The intermediate outer peripheral tapered section 22 forms a fourth flow passage section 54 between itself and the second tapered section 15. In this embodiment, the intermediate outer peripheral tapered section 22 is a conical surface (tapered surface) with a single gradient that continues to the cylindrical section in the downstream portion of the main body 25, but this may be a conical surface with multiple gradients, or an arcuate surface that gradually expands toward the downstream side.

[0032] The fourth flow path section 54 has a cross-sectional area of ​​the flow path expanding between the second taper section 15, which gradually expands in diameter toward the downstream side in the axial direction, and the intermediate outer periphery taper section 22, which gradually expands in diameter toward the downstream side in the axial direction.

[0033] Between the second flow path section 52 and the fourth flow path section 54, there is provided a third flow path section 53, which has a larger cross-sectional area of ​​the flow path than the second flow path section 52 and the fourth flow path section 54, and generates negative pressure within the flow path by expanding the cross-sectional area.

[0034] The third flow passage portion 53 is formed between the outer surface 36 of the connecting portion 35 connecting the piece member 30 and the main body portion 25, the second tapered portion 15, the downstream end surface 33 of the piece member 30, and the upstream end surface 23 of the main body portion 25. The outer surface 36 of the connecting portion 35 is located farther from the second tapered portion 15 than the upstream outer peripheral tapered portion 31 and the intermediate outer peripheral tapered portion 22. In other words, the outer surface 36 of the connecting portion 35 is located closer to the axis of the flow passage than the upstream outer peripheral tapered portion 31 and the intermediate outer peripheral tapered portion 22. Therefore, when the fluid flows from the second flow passage portion 52 to the third flow passage portion 53, the cross-sectional area of ​​the flow passage increases rapidly from the second flow passage portion 52 to the third flow passage portion 53, and the expansion of the cross-sectional area generates negative pressure in the flow passage. With this combination of features, if there is a certain amount of fluid pressure (water pressure) flow, a large amount of cavitation can be easily generated, and a large amount of fine bubbles consisting of air dissolved inside and liquid vapor can be generated. In other words, the generation of fine bubbles can be achieved in any flow passage of any diameter, not just in small diameter pipes as in the past.

[0035] At the downstream end of the connecting portion 35, the upstream end of the intermediate outer peripheral tapered portion 22 is smoothly connected by an end face 23 perpendicular to the axis and a circular arc surface 24 connecting the end face 23 and the intermediate outer peripheral tapered portion 22. This prevents the smooth flow of water downstream.

[0036] Here, the first flow passage section 51 has a shape in which the cross-sectional area of ​​the flow passage gradually decreases along the flow direction of the flow passage until the water reaches the third flow passage section 53, and this reduction in the cross section increases the momentum of the water flowing downstream. The subsequent second flow passage section 52 smoothly guides the fluid toward the third flow passage section 53 while expanding slightly in the outer diameter direction along the flow direction of the flow passage (while the cross-sectional area of ​​the flow passage expands slightly). This shape also contributes to the generation of a large amount of cavitation. In addition, the first tapered section 12 and the second tapered section 15, which are configured with opposite gradients, form a Venturi mechanism, and the step (the step formed by the upstream outer peripheral tapered section 31 and downstream end face 33 of the piece member 30, and the outer surface 36 of the connecting section 35, etc.) that constitutes the third flow passage section 53 is provided immediately downstream of the Venturi mechanism, which also contributes to the generation of a large amount of cavitation.

[0037] Here, it is desirable that the angle α between the downstream end surface 33 of the piece member 30 in the third flow passage portion 53 and the generating line of the upstream outer peripheral tapered portion 31 is an acute angle (see acute angle α in FIG. 1). The flow passage is bent at an acute angle, so that the generation of negative pressure becomes more pronounced. In addition, in this embodiment, the downstream end surface 33 of the piece member 30 is configured to have an inclined surface 34 that approaches the upstream side as it moves away from the second tapered portion 15, so that the acute angle is further reduced to increase the degree of cavitation generation. In other words, the amount of fine bubbles generated can be further increased by shearing the cavitation in a swirling manner. In this embodiment, as shown in FIG. 9B, the inclined surface 34 is provided around the entire circumference of the downstream end surface 33, but the inclined surface 34 may be provided only in a partial direction around the axis of the downstream end surface 33.

[0038] Here, in the second flow path section 52 and the fourth flow path section 54, the second taper section 15 and the upstream outer circumferential taper section 31, and the second taper section 15 and the intermediate outer circumferential taper section 22 may be configured to be parallel to each other, respectively.

[0039] A position adjustment mechanism for adjusting the position of the piece member 30 relative to the casing 11 and a method for adjusting fine bubbles using the same will be described.

[0040] The position adjustment mechanism includes an adjustment member 80 provided between the first member 20 and the casing 11, or between the first member 20 and a socket 70 fixed to the casing 11, and the adjustment member 80 is screwed to the first member 20 and the casing 11 or to the first member 20 and the socket 70.

[0041] 12A and 12B, the socket 70 is constituted by an annular member 73, and has an internal thread portion 71 formed on its inner periphery. The inner surface downstream of the internal thread portion 71 is the conical inner surface 72 described above.

[0042] The female thread 71 on the inner circumference of the socket 70 is screwed into the male thread 19 of the casing 11, and the axial position of the socket 70 relative to the casing 11 can be adjusted by increasing or decreasing the amount of screwing. When the socket 70 reaches a predetermined axial position relative to the casing 11, the lock ring 60 is screwed into the male thread 19 from the upstream side. The lock ring 60 is tightened until it contacts the end face of the socket 70, and the socket 70 is firmly fixed to the casing 11. This allows the length of the micro-bubble generator 10 to be adjusted, and the downstream cavitation state can be adjusted by adjusting the downstream volume of the piece member 30. The method of fixing the casing 11 and the socket 70 is not limited to the above-mentioned fixing method, and they may be fixed by mechanical joining such as snap ring fixing, key fixing, and bolting, or metallurgical joining such as welding. The casing 11 and the socket 70 may also be integrated into one part.

[0043] 13A, 13B, and 13C, the adjustment member 80 is composed of an annular member 85, with a female screw portion 82 formed on its inner circumference and a male screw portion 81 formed on its outer circumference. A truncated cone-shaped protrusion 86 is provided on the upstream end face of the adjustment member 80. The protrusion 86 is provided so as to surround the upstream opening of the female screw portion 82, forming an annular protrusion over the entire circumference. Note that a flow path 84 penetrating the adjustment member 80 from front to back is divided into a plurality of flow path portions by a plurality of holding portions 83 provided intermittently along the circumferential direction (see FIGS. 5 and 13A).

[0044] The female screw portion 82 of the adjustment member 80 is screwed into the male screw portion 21 formed on the outer periphery of the main body portion 25 of the first member 20, and the axial position of the adjustment member 80 relative to the first member 20 can be adjusted by increasing or decreasing the amount of screwing. When the adjustment member 80 reaches a predetermined axial position relative to the first member 20, the male screw portion 81 on the outer periphery of the adjustment member 80 is screwed into the female screw portion 71 of the socket 70 from the downstream side. The adjustment member 80 is tightened until it hits the end face of the casing 11, so that the adjustment member 80 and the first member 20 are firmly fixed to the casing 11. Here, by setting the axial positional relationship between the adjustment member 80 and the first member 20 in advance, it is easy to set the relative positional relationship between the first member 20 and the casing 11. Note that when the casing 11 and the socket 70 are configured as an integral member, that is, when the socket 70 is omitted, the adjustment member 80 is provided between the first member 20 and the casing 11.

[0045] Further, the second member 40, which can be freely advanced and retreated along the axial direction, is screwed to the main body 25 of the first member 20. As shown in Figs. 10A and 10B, the second member 40 is a truncated cone-shaped member having a downstream outer peripheral tapered portion 43 on its outer surface, the diameter of which increases from the upstream side to the downstream side, a downstream end face 45 that closes the bottom of the downstream outer peripheral tapered portion 43, and an upstream end face 42 provided at the upstream end of the downstream outer peripheral tapered portion 43. In this embodiment, the downstream outer peripheral tapered portion 43 is a conical surface (tapered surface) with a single gradient that continues from the upstream end to the downstream end of the second member 40, but this may be a conical surface with multiple gradients, or a circular arc surface that gradually expands toward the downstream side. The second member 40 has a female screw portion 44 formed along its axis. The female thread portion 44 of the second member 40 is screwed into the male thread portion 21 formed on the outer periphery of the main body portion 25 of the first member 20, and the axial position of the second member 40 relative to the first member 20 can be adjusted by increasing or decreasing the amount of screwing.

[0046] By adjusting the position of the second member 40 relative to the first member 20, that is, by adjusting the position of the second member 40 relative to the casing 11 or the socket 70, the properties of the generated fine bubbles can be adjusted. In addition, the water spray pressure, water spray direction, and water spray pattern can also be adjusted. Here, as shown in FIG. 1, if the second member 40 is screwed in until it abuts against the downstream end face of the adjustment member 80 located upstream of it, it will be firmly fixed to the first member 20 without loosening. In FIG. 1, the piece member 30 is arranged across the ridge line portion 18, that is, it is arranged across the first tapered portion 12 and the second tapered portion 15 and facing each other, but it is also possible to use the piece member 30 in a state where the entire piece member 30 is located downstream of the ridge line portion 18.

[0047] In this way, since the piece member 30 (first member 20) is detachable from the casing 11, and the second member 40 is detachable from the first member 20, after removing the piece member 30 (first member 20) or the second member 40, it is possible to change the state of cavitation and adjust the properties of the fine bubbles by replacing it with another piece member 30 (first member 20) or second member 40 having a different shape (including surface treatment method). The water shape pattern of the water spray can also be adjusted. In addition, since the parts can be detached, it is easy to replace or repair parts when they are damaged, improving maintainability.

[0048] For example, FIG. 10C shows a second member 40 having a different shape from those shown in FIG. 10A and FIG. 10B. The ridge between the downstream outer peripheral tapered portion 43 and the downstream end face 45 is a smooth cross-sectional arc-shaped portion 43a. Second members 40 having different elevation angles of the downstream outer peripheral tapered portion 43 with respect to the axis and second members 40 having different lengths of the downstream outer peripheral tapered portion 43 in the axial direction can be used. In addition, second members 40 having a truncated pyramid shape or an opening that is eccentric from the central axis can also be used. Furthermore, second members 40 having spiral ridges or grooves formed on the downstream outer peripheral tapered portion 43 to generate a swirling flow can also be used.

[0049] For example, when watering a lawn or farm, it is possible to select a second member 40 having a shape that can create a shower-like water pattern so that water can be sprayed over a wide area. On the other hand, when watering a sewage river to remove sewage, it is possible to select a second member 40 having a shape that can create a linear water pattern with high water pressure so that sewage can be easily removed.

[0050] There are no particular limitations on the surface treatment of components such as the inner surface of the casing 11, the first member 20, the adjustment member 80, and the second member 40, but by selectively using multiple components whose surface roughness has been changed by surface treatment, the properties of the fine bubbles can be changed.

[0051] The internal structure of the casing 11 that generates fine bubbles is not limited to the Venturi tube shape as in this embodiment, and may be various shapes that have the function of generating fine bubbles. For example, the first tapered portion 12 of the casing 11 may be omitted, and the inner surface of the casing 11 upstream of the ridge portion 18 may be a cylindrical surface. In addition, the internal structure of the casing 11 may be appropriately selected from round pipes, irregular pipes, and shapes that combine these, depending on the required properties of the fine bubbles.

[0052] The shape of the piece 30 is not limited to the cone shape of this embodiment, and may be a cylinder, a cone, a prism, a pyramid, or a combination of these shapes, depending on the properties of the microbubbles to be generated. Also, the piece 30 may have a cone surface on which spiral ridges or grooves are formed to generate a swirling flow.

[0053] In the modification shown in Fig. 7, a seat 90 is used. As shown in Figs. 14A and 14B, the seat 90 is composed of an annular member 93, and a male screw portion 91 is formed on its outer periphery. An inner surface 92 of the seat 90 has a larger diameter than the outer surface of the main body portion 25 of the first member 20, and a gap between the inner surface 92 of the seat 90 and the outer surface of the main body portion 25 serves as an opening for ensuring a flow path. Reference numeral 94 in the figure denotes a key groove, which is used when rotating the seat 90 around its axis relative to the first member 20.

[0054] The male threaded portion 91 of the base 90 is screwed into the female threaded portion 71 of the socket 70, and the axial position of the base 90 relative to the first member 20 can be adjusted by increasing or decreasing the amount of screwing. When the base 90 reaches a predetermined axial position relative to the first member 20, the adjustment member 80 is screwed in from the downstream side until it abuts against the downstream end face of the base 90. This ensures that the base 90 and the adjustment member 80 are firmly fixed to the first member 20 without loosening. Using the base 90 makes it easy to fix the adjustment member 80 to any axial position of the first member 20, regardless of the position of the downstream end face of the casing 11.

[0055] Note that, like the fixing structure of the first member 20 to the casing 11 and the socket 70, the fixing structure of the second member 40 to the first member 20 is not limited to the above embodiment. For example, it is possible to fix the second member 40 to the first member 20 using a lock ring or a snap ring, and to make the position adjustable in the axial direction. It is also possible to fix and adjust the position in the axial direction in stages using key fixing or the like. It is also possible to mold the first member 20 and the second member 40 as a single unit, or to completely fix them by metallurgical joining such as welding.

[0056] The assembly method of each part will be described below. The assembly of the fine bubble generator 10 of this embodiment (the embodiment of FIG. 7) is carried out in the following procedure. The socket 70 and the lock ring 60 are already fixed to the casing 11. (i) The base 90 is screwed to the socket 70. (ii) The adjustment member 80 is screwed to the first member 20 at an arbitrary position, and the second member 40 is screwed to the downstream side of the adjustment member 80 at an arbitrary position. (iii) The axial position of the adjustment member 80 relative to the first member 20 is determined and aligned, and the second member 40 is tightened to fit the adjustment member 80. (iv) The adjustment member 80 is screwed into the socket 70 and fixed.

[0057] When removing the first member 20 from the casing 11, or when removing the second member 40 from the first member 20, the above steps are reversed.

[0058] Another embodiment of the present invention is shown in Fig. 15. In this embodiment, the first member 20 and the second member 40 are molded as an integral member. The following description will focus on the differences from the previous embodiment. In Fig. 15, parts having the same functions as the previous embodiment are denoted by the same reference numerals.

[0059] The shape of the piece 30 of the first member 20 is the same as in the above-described embodiment, and has a conical surface (upstream outer circumferential tapered portion 31) on its outer surface that expands in diameter from the upstream side toward the downstream side. The main body 25 of the first member 20 also has an intermediate outer circumferential tapered portion 22, and the outer periphery of the second member 40 has a downstream outer circumferential tapered portion 43. The intermediate outer circumferential tapered portion 22 and the downstream outer circumferential tapered portion 43 are connected so that their conical surfaces are continuous with each other.

[0060] In this embodiment, the upstream outer peripheral tapered portion 31 of the piece member 30, the intermediate outer peripheral tapered portion 22 of the main body portion 25, and the downstream outer peripheral tapered portion 43 of the second member 40 are each a conical surface (tapered surface) with a single gradient that continues from the upstream end to the downstream end, but they may also each be a conical surface with a compound gradient, or an arcuate surface that gradually widens toward the downstream side.

[0061] The position adjustment mechanism is provided between the second member 40 and the casing 11. A cylindrical operating member 48 is connected to the outer periphery of the second member 40. A plurality of holding portions 47 protruding toward the outer diameter side are radially provided at the downstream end of the second member 40, and these holding portions 47 support the operating member 48 to the second member 40. A fourth flow passage portion 54 between the intermediate outer periphery tapered portion 22 and the second tapered portion 15, and between the downstream outer periphery tapered portion 43 and the second tapered portion 15 is divided into a plurality of flow passage portions by a plurality of holding portions 47 provided intermittently along the circumferential direction, so that water is discharged downstream.

[0062] The operating member 48 has a flange portion 49 protruding toward the outer diameter side, and the downstream end of the operating shaft 56 is press-fitted and fixed into a hole 49a that penetrates the flange portion 49. The outer periphery of the casing 11 has a flange portion 59 protruding toward the outer diameter side, and a male screw portion provided at the upstream end of the operating shaft 56 is screwed into a female screw hole 59a that penetrates the flange portion 59. A nut 58 is screwed into the upstream end of the operating shaft 56 via a washer 57. By screwing the nut 58 into the flange portion 59, the operating shaft 56 moves toward the upstream side, and by loosening the nut 58, the operating shaft 56 moves toward the downstream side. The axial positions of the first member 20 and the second member 40 relative to the casing 11 can be adjusted by increasing or decreasing the amount of screwing of the nut 58. The operating member 48, the operating shaft 56, the nut 58, etc. constitute a position adjustment mechanism. That is, the properties of the generated fine bubbles can be adjusted by adjusting the position of the second member 40 relative to the casing 11. In addition, the water spray pressure, water spray direction, and water spray pattern can also be adjusted.

[0063] In addition, reference numeral 48a in FIG. 15 denotes a bearing that smoothly maintains relative axial movement between the casing 11 and the operating member 48, and reference numeral 48b denotes an O-ring for waterproofing.

[0064] Furthermore, if the outer peripheral surface of the first member 20 or the second member 40 is brought into close contact with the second tapered portion 15 over the entire area around the axis, the water spray can be completely stopped (water can be stopped). This is the same as in the above-mentioned embodiment. In this embodiment, the upstream outer peripheral tapered portion 31 and the second tapered portion 15, the intermediate outer peripheral tapered portion 22 and the second tapered portion 15, and the downstream outer peripheral tapered portion 43 and the second tapered portion 15 are parallel conical surfaces, respectively, so that the surface contact between the two increases the degree of contact and improves the water stopping ability. Note that when the water stopping pressure becomes large, it is preferable to stop the water at the portion downstream of the piece member 30 in consideration of the strength.

[0065] In the above embodiment, the position of the casing 11 and the piece member 30 is adjusted along the water flow direction, but the direction of the position adjustment of the casing 11 and the piece member 30 is not limited to this embodiment. For example, as shown in Fig. 16, a long first member 20 having a piece member 30 at its tip may be movable forward and backward in a direction intersecting the water flow direction (axial direction of the flow channel) in the casing 11. In Fig. 16, the first member 20 is movable forward and backward in a direction perpendicular to the water flow direction (axial direction of the flow channel) (see arrow C). This forward and backward movement allows the properties of the fine bubbles to be adjusted.

[0066] In the example of Fig. 16, a male screw portion 21 is formed on the outer periphery of the first member 20, and a female screw portion 11a is formed on the inner surface of a hole that penetrates the inside and outside of the casing 11 in the radial direction, thereby constituting a position adjustment mechanism. By rotating the first member 20 around the axis of the female screw portion 11a, it is possible to adjust the amount of protrusion of the first member 20 into the flow path. The configuration of the position adjustment mechanism is not limited to this example, and any well-known means that can adjust the amount of protrusion of the first member 20 into the flow path can be used. Furthermore, the shapes of the first member 20 and the piece member 30 are not limited to this example either.

[0067] In the above embodiment, one fine-bubble generator 10 is attached to the end of the flow path, but it is also possible to use a bundle of multiple fine-bubble generators 10 at the end of the flow path. This allows water containing fine bubbles to be released simultaneously from multiple fine-bubble generators 10.

[0068] In the above embodiment, the fine-bubble generator 10 is disposed at the end of the flow path, but the fine-bubble generator 10 may also be installed midway through the flow path by interposing a casing 11 between the upstream flow path 1 (inlet pipe 1) and the downstream flow path (outlet pipe). [Explanation of symbols]

[0069] 1 Upstream flow path (inflow pipe) 10. Microbubble generator 11 Casing 12 First taper section 15 Second taper section 20 First member 22 Intermediate outer peripheral tapered section 25 Main body 30. Link material 31 Upstream outer periphery tapered section 33 Downstream end face 34 Slope 35 Connecting part 36 Exterior 40 Second member 42 Upstream end face 43 Downstream outer periphery tapered section 51 First flow path section 52 Second flow path section 53 Third flow path section 54 Fourth flow path section

Claims

1. A casing (11) having a flow path forming space (C) connecting an upstream side and a downstream side; A frame member (30) provided inside the casing (11), A micro-bubble generator that generates micro-bubbles in a liquid by causing the liquid to flow between an inner surface of the flow passage forming space (C) and an outer surface of the piece member (30), The fine bubble generating device is provided with a position adjustment mechanism for adjusting the positions of the casing (11) and the piece member (30).

2. 2. The fine-bubble generator according to claim 1, wherein the positions of the casing (11) and the piece member (30) are adjusted along the flow direction of the liquid.

3. the inner surface of the flow path forming space (C) includes a first tapered portion (12) whose diameter decreases from the upstream side toward the downstream side, and a second tapered portion (15) that is provided downstream of the first tapered portion (12) on the inner surface of the flow path forming space (C) and whose diameter increases from the upstream side toward the downstream side, 3. The fine-bubble generator according to claim 2, wherein the top member (30) has an upstream outer peripheral tapered portion (31) whose diameter increases from the upstream side toward the downstream side, and forms a second flow path portion (52) between the top member (30) and the second tapered portion (15).

4. The inner surface of the flow passage forming space (C) is provided with a second tapered portion (15) whose diameter increases from the upstream side toward the downstream side, 3. The fine-bubble generator according to claim 2, wherein the top member (30) has an upstream outer peripheral tapered portion (31) whose diameter increases from the upstream side toward the downstream side, and forms a second flow path portion (52) between the top member (30) and the second tapered portion (15).

5. 5. The fine bubble generator according to claim 4, wherein the piece member (30) has a downstream end face (33) at a downstream end of the upstream outer peripheral tapered portion (31), and an angle (α) between the downstream end face (33) and a generatrix of the upstream outer peripheral tapered portion (31) is an acute angle.

6. 6. The fine bubble generator according to claim 5, wherein the downstream end surface (33) is an inclined surface (34) approaching the upstream side as it moves away from the second tapered portion (15).

7. The top member (30) is provided at the upstream end of a longitudinal first member (20) extending along the flow direction of the liquid, 2. The fine bubble generator according to claim 1, wherein the position adjustment mechanism comprises an adjustment member (80) provided between the first member (20) and the housing (11) or between the first member (20) and a socket (70) fixed to the housing (11), and the adjustment member (80) is screwed to the first member (20) and the housing (11) or to the first member (20) and the socket (70).

8. The top member (30) is provided at the upstream end of a longitudinal first member (20) extending along the flow direction of the liquid, 2. The fine-bubble generator according to claim 1, wherein a second member (40) is screwed to the first member (20) downstream of the top member (30) so as to be freely movable back and forth along the longitudinal direction thereof, and the second member (40) is provided on its outer surface with a downstream outer peripheral tapered portion (43) whose diameter increases from the upstream side toward the downstream side.

9. The fine bubble generator according to claim 8, wherein the second member (40) is detachable from the first member (20).

10. 2. The fine-bubble generator according to claim 1, wherein the first member (20) is provided with an intermediate outer peripheral tapered portion (22) downstream of the top member (30) and the diameter of the intermediate outer peripheral tapered portion (22) increases from the upstream side toward the downstream side, the intermediate outer peripheral tapered portion (22) forms a fourth flow path portion (54) between the second tapered portion (15), and a third flow path portion (53) is provided between the second flow path portion (52) and the fourth flow path portion (54), the third flow path portion (53) having a larger cross-sectional area of ​​the flow path than the second flow path portion (52) and the fourth flow path portion (54) and generating negative pressure in the flow path.

11. A piece (30) for use in the fine bubble generator according to any one of claims 1 to 10, the piece (30) being connected to the casing (11) via the position adjustment mechanism.

12. 10. A first member (20) having a top member (30) for use in the fine bubble generator according to claim 9, wherein the second member (40) is detachable from the first member.

13. Using the fine bubble generator according to any one of claims 1 to 10, The method for adjusting fine bubbles comprises adjusting the position of the piece member (30) relative to the casing (11).

14. Using the fine bubble generator according to claim 9, The method for adjusting fine bubbles comprises removing the second member (40) from the first member (20) and then attaching another second member (40) having a shape different from that of the second member (40) to the first member (20).

Images