JP2013215634A - Fine air bubble generator - Google Patents

Abstract

PROBLEM TO BE SOLVED: To stably generate a large amount of fine air bubbles while suppressing pressure loss of a flow path.SOLUTION: A fine air bubble generator 1 includes a fine air bubble generation path 2, gas-liquid supply piping 5, a pump 6, an air introducing port 7, a swirl flow maintaining path 8, and a refinement acceleration member 11, etc. The fine air bubble generation path 2 generates refined air bubbles in a liquid by making gas-liquid flowing in from an inlet 3 flow out from an outlet 4 in a swirl flow state. The gas-liquid that flows out from the outlet 4 flows inside the cylindrical swirl flow maintaining path 8 while maintaining the swirl flow. At the time, large air bubbles that cannot be completely refined in the fine air bubble generation path 2 pass through vent holes 11a of the refinement acceleration member 11 formed in a cylindrical shape from an outer peripheral side to an inner peripheral side, and are thus re-refined. Thus, a large amount of fine air bubbles can be stably generated without increasing the pressure loss of the flow path.

Description

  The present invention relates to a fine bubble generator capable of generating fine bubbles in water.

  In general, as a means for generating fine bubbles in water, a venturi type, a cavitation type, a pressure dissolution type, a swirl type, and the like are known. The Venturi type has a constricted part (throttle) in the flow path of water, and when the flow velocity increases at this constricted part, air is sucked in from the outside, and the sucked air rises in the part where the constriction spreads By making it finer. In the cavitation type, bubbles are generated using cavitation by feeding a gas-liquid mixture into a pump and applying ultrasonic vibration, for example. In addition, the pressure dissolution type is a method in which outside air introduced into a pipe through which water flows is pressurized by a pump or the like and dissolved in water, and although the apparatus is enlarged, a large amount of outside air can be dissolved. .

  In addition, as described in Patent Document 1, the swirling flow type forms a swirling flow of water and merges the swirling flow with air, and the air is sheared and pulverized by the swirling flow. . The swirling flow method is an excellent method among the above methods because fine bubbles can be generated even if the flow rate of water flowing in the flow path is small. In order to increase the amount of fine bubbles generated by the swirling flow method, increase the amount of air introduced, increase the shear force of the air by increasing the speed of the swirling flow, and the contact area between the swirling flow and air. It is important to increase it.

Japanese Patent No. 4525890

  However, in the above-described swirling flow type device, when the specifications of the pump that forms the water flow are limited, the flow rate, head, water pressure, and the like of the water flowing through the flow path are limited. Since the swirl force of water greatly depends on the flow rate and water pressure, if the amount of air introduced is increased in the presence of the above restrictions, all of the introduced air will flow downstream without being sheared, resulting in small bubbles. In addition, there is a problem that large bubbles are also generated.

  The present invention has been made to solve the above-described problems, and provides a fine bubble generator capable of increasing the amount of fine bubbles generated while suppressing pressure loss in a flow path. With the goal.

  The fine bubble generating apparatus according to the present invention has a gas-liquid inlet and an outlet, and the gas-liquid flowing from the inlet flows out of the outlet in a swirling state, thereby making the bubbles finer in the liquid , A liquid supply means for supplying liquid to the inlet of the fine bubble generation passage, a gas supply means for supplying gas to the inlet of the fine bubble generation path, and an outlet of the fine bubble generation passage And a swirl flow maintaining passage for maintaining a swirling flow of gas and liquid flowing out from the outlet, and a swirl flow maintaining passage, which is provided in the swirl flow maintaining passage and promotes miniaturization to further refine the bubbles by contacting the bubbles in the swirling flow state And a member.

  According to the present invention, fine bubbles can be generated in the liquid by the fine bubble generation passage, and further, the large bubbles that have not been completely refined by the fine bubble generation passage can be re-refined by the miniaturization promoting member. . Thereby, even if it does not increase the pressure loss of a flow path, a lot of fine bubbles can be generated stably and the performance of a fine bubble generating device can be improved.

It is sectional drawing which shows typically the fine bubble generator by Embodiment 1 of this invention. It is an expanded sectional view which expands and shows a part of swirl flow maintenance channel | path and the miniaturization promotion member in FIG. It is sectional drawing which shows typically the fine bubble generator by Embodiment 2 of this invention. It is the end elevation which looked at the swirl | vortex flow maintenance channel | path and the refinement | miniaturization promotion member in FIG. 3 from the edge part of an axial direction.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. The present invention is not limited to Embodiments 1 and 2 described below. Moreover, the same code | symbol is attached | subjected to the element which is common in each figure, and the overlapping description is abbreviate | omitted.

Embodiment 1 FIG.
First, Embodiment 1 of the present invention will be described with reference to FIG. 1 and FIG. FIG. 1 is a configuration diagram schematically showing a microbubble generator according to Embodiment 1 of the present invention. The fine bubble generating device 1 includes a fine bubble generation passage 2, a gas / liquid supply pipe 5, a pump 6, an air introduction port 7, a swirl flow maintenance passage 8, a miniaturization promoting member 11, and the like. The fine bubble generation passage 2 is formed in a conical shape that gradually decreases in diameter from the proximal end (bottom) to the distal end. The fine bubble generating passage 2 includes an inflow port 3 provided on the outer periphery of the base end portion having a circular shape, and a circular outflow port 4 provided at the distal end portion. And the fine bubble production | generation channel | path 2 produces | generates the bubble which refined | miniaturized in the liquid by making the liquid and gas (gas-liquid) which flowed in from the inflow port 3 flow out of the outflow port 4 in a swirl flow state. For this reason, the inner wall of the fine bubble generation passage 2 is formed as a high-density and smooth wall surface, and is configured to increase the flow velocity while suppressing the pressure loss of the swirling flow.

  The gas / liquid supply pipe 5 supplies gas / liquid to the fine bubble generation passage 2 and is connected to the inlet 3 in a state of being inclined in a tangential direction with respect to the outer periphery of the base end portion of the fine bubble generation passage 2. . Further, the inflow port 3 is formed as a throttle portion having a diameter smaller than that of the gas-liquid supply pipe 5. For this reason, the gas-liquid flowing from the gas-liquid supply pipe 5 into the fine bubble generation passage 2 swirls along the inner wall of the fine bubble generation passage 2 in a state where the flow velocity is increased by the inflow port 3, and the swirl flow is facilitated. Cause it to occur. Further, a gas 6 (for example, air) is supplied to the gas / liquid supply pipe 5 as a liquid supply means for supplying a liquid (for example, water) to the inlet 3 of the fine bubble generating passage 2 and a gas inlet (for example, air) to the inlet 3. An air introduction port 7 is provided as a gas supply means.

  Since the pump 6 needs to operate normally even in a state where gas and liquid are mixed, it is preferable to configure the pump 6 with a vortex pump or the like capable of discharging gas and liquid. The pump 6 includes a foreign matter trapping mechanism that prevents foreign matter from getting tangled in the pump rotor blades. On the other hand, the air introduction port 7 is connected to the gas-liquid supply pipe 5 on the discharge side of the pump 6 and, for example, in the vicinity of a throttle portion (not shown) formed by reducing the diameter of a part of the gas-liquid supply pipe 5. Is arranged. Thereby, the air introduction port 7 is configured to suck air into the gas-liquid supply pipe 5 by using a negative pressure generated by increasing the flow velocity of the liquid at the throttle portion. When the pressure loss generated downstream of the air introduction port 7 is large, the air suction operation is hindered. Therefore, an air feed pump or the like is employed as the gas supply means, and the gas / liquid supply pipe 5 is connected to the air introduction port 7. Air may be forcibly supplied. In this case, a check valve is connected between the air supply pump and the air inlet 7.

  Next, the swirl flow maintaining passage 8 and the miniaturization promoting member 11 which are characteristic items of the present embodiment will be described. The swirl flow maintaining passage 8 is for moving the gas and liquid in the axial direction of the swirl flow while maintaining the swirl flow of the gas and liquid flowing out from the outlet 4 of the fine bubble generating passage 2. In the following description, the circumferential direction and the axial direction of the swirl flow maintaining passage 8 having a cylindrical shape are referred to as a swirl direction and an axial direction of the swirl flow, respectively. The swirl flow maintaining passage 8 is formed in a substantially cylindrical shape having a diameter larger than that of the outlet 4, and is arranged coaxially with the fine bubble generating passage 2. Further, the swirl flow maintaining passage 8 is connected to the outlet 4 at one end side, and has a substantially conical diameter-expanded portion 9 that gradually increases in diameter from one end side toward the other end side, and the other end side of the diameter-expanded portion 9. And a cylindrical equal-diameter portion 10 connected to the. The inner wall of the swirl flow maintaining passage 8 is formed as a high-density and smooth wall surface like the fine bubble generation passage 2 and is configured to increase the flow velocity while suppressing the pressure loss of the swirl flow.

  The miniaturization promoting member 11 comes into contact with the bubbles swirling in the swirling flow maintaining passage 8 and further refines the bubbles. As shown in FIGS. 1 and 2, the miniaturization promoting member 11 is formed in a cylindrical shape by a porous material or a mesh material, and has a large number of air holes 11a having a fine pore diameter of, for example, 1 μm or less. FIG. 2 is an enlarged cross-sectional view showing a part of the swirl flow maintaining passage and the miniaturization promoting member in FIG. Further, the miniaturization promoting member 11 is disposed coaxially (concentrically) inside the swirl flow maintaining passage 8. Thereby, the space in the swirl flow maintaining passage 8 includes a cylindrical inner peripheral space 12 located on the inner peripheral side of the miniaturization promoting member 11 and an annular outer peripheral space 13 located on the outer peripheral side of the miniaturization promoting member 11. These spaces 12 and 13 communicate with each other through a large number of air holes 11a.

  The fine bubble generating apparatus 1 according to the present embodiment has the above-described configuration, and the operation thereof will be described next. First, when the pump 6 is operated, liquid is supplied from the gas / liquid supply pipe 5 to the fine bubble generation passage 2 and gas is sucked into the gas / liquid supply pipe 5 from the air inlet 7 due to the negative pressure generated by the flow of the liquid. . These gas and liquid are introduced into the outer periphery of the base end portion from the inlet 3 of the fine bubble generation passage 2 and swirl along the inner wall of the fine bubble generation passage 2 as shown in FIG. Cause it to occur.

  Further, since the fine bubble generating passage 2 is formed in a conical shape, the swirling flow of the gas and liquid generated at the base end portion proceeds in the axial direction (axial direction of the swirling flow) toward the outlet 4, The turning radius is gradually reduced, and the flow velocity (swivel speed) and pressure increase. As a result, at the outlet 4 located at the top of the conical shape, the gas and liquid are separated by the high-speed swirling flow, and the bubbles are gathered near the swirling center. As a result, when the gas and liquid flow out of the outlet 4 while maintaining the swirling flow, the bubbles in the pressure-released liquid expand on the inner peripheral side of the swirling flow. The bubbles are finely sheared by coming into contact with the inner periphery of the swirling flow, and fine bubbles are generated. As described above, according to the fine bubble generation passage 2, the swirling flow of gas and liquid is increased in speed and pressure by using the conical passage whose diameter is reduced from the base end portion toward the tip portion, By releasing the pressure from the outlet 4 and releasing the pressure, fine bubbles can be generated in the liquid.

  Here, when the gas-liquid flows out from the outlet 4, the larger the amount of gas mixed in the liquid, the larger the amount of gas that is sheared by the swirling flow, and the more bubbles are generated. However, when the amount of introduced gas is increased, the swirl flow generated in the fine bubble generation passage 2 becomes weak, so that the gas that cannot be sheared by the swirl flow tends to remain as large bubbles. For this reason, in this Embodiment, the swirl | vortex flow maintenance channel | path 8 and the refinement | miniaturization promotion member 11 are arrange | positioned in the outflow port 4 of the microbubble production | generation channel | path 2. FIG.

  According to this configuration, the swirling flow of gas and liquid flowing out from the outlet 4 to the swirling flow maintaining passage 8 is opened from the small diameter outlet 4 to the large diameter swirling flow maintaining passage 8, thereby providing a constant swirling center. In this state, the diameter gradually increases along the enlarged diameter portion 9 of the swirling flow maintaining passage 8 and finally turns along the inner wall of the equal diameter portion 10. At this time, the enlarged diameter portion 9 can gradually increase the turning radius to the inner diameter position of the equal diameter portion 10 without disturbing the swirling flow of gas and liquid. When the gas-liquid flowing out from the fine bubble generation passage 2 turns in the swirl flow maintaining passage 8, as shown in FIG. 2, the bubbles B1 refined by the fine bubble production passage 2 and the large bubbles B2 that have not been refined are obtained. Is separated into individual flow paths by the miniaturization promoting member 11.

  Specifically, fine bubbles having an outer diameter of 200 μm or less generally collect on the outer peripheral side of the swirling flow, and large bubbles having an outer diameter of 200 μm or more tend to collect on the center (inner peripheral side) of the swirling flow. For this reason, in the state where the swirling flow of the gas and liquid is maintained, the fine bubbles B <b> 1 stay in the outer peripheral space 13 of the miniaturization promoting member 11. On the other hand, since the large bubbles B2 move to the inner peripheral space 12 through the vent holes 11a of the miniaturization promoting member 11 by the action of the swirling flow, they are refined when passing through the vent holes 11a and become the fine bubbles B1. .

  As described above, according to the present embodiment, fine bubbles can be generated in the liquid by the fine bubble generation passage 2, and further, the large bubbles that have not been completely refined by the fine bubble generation passage 2 are generated by the miniaturization promoting member. By passing through 11, it is possible to re-fine large bubbles. Therefore, a large amount of fine bubbles can be stably generated without increasing the pressure loss of the flow path, and the performance of the fine bubble generating device 1 can be improved. Further, since the miniaturization promoting member 11 is made of a porous material or a mesh material, large bubbles can be easily made fine by using the vent holes 11a, and fine bubbles can be efficiently generated with a simple structure. Can do.

  Further, since the miniaturization promoting member 11 is formed in a cylindrical shape, the wall surface of the miniaturization promoting member 11 can be extended in the swirling direction and the axial direction (gas-liquid flow direction) of the swirling flow. Thereby, the pressure loss which arises when a swirling flow contacts with the refinement | miniaturization promotion member 11 can be suppressed, the operating efficiency of the pump 6 can be improved, and the production amount of fine bubbles can be improved. Further, by using the cylindrical miniaturization promoting member 11, large bubbles and fine bubbles can be separated into the inner peripheral space 12 and the outer peripheral space 13 of the miniaturization promoting member 11, and the fine bubbles are separated from the large bubbles. Combining and disappearing can be suppressed. Furthermore, since the fine bubble generating passage 2, the swirl flow maintaining passage 8, and the miniaturization promoting member 11 are arranged coaxially, the flow path can be configured linearly along these central axes, and the pressure loss of the flow path Can be further reduced.

Embodiment 2. FIG.
Next, a second embodiment of the present invention will be described with reference to FIGS. FIG. 3 is a cross-sectional view schematically showing a microbubble generator according to Embodiment 2 of the present invention, and FIG. 4 shows the swirl flow maintaining passage and the miniaturization promoting member in FIG. 3 from the end in the axial direction. FIG. Although the microbubble generator 1 of the present embodiment is configured in substantially the same manner as that of the first embodiment, a radial micronization promoting member 20 is disposed inside the swirl flow maintaining passage 8. The miniaturization promoting member 20 is formed by assembling a plurality of plate materials 21 made of, for example, a porous material or a mesh material, and a large number of air holes 20a having fine pore diameters of 1 μm or less are opened over the whole.

  Further, as shown in FIGS. 3 and 4, the miniaturization promoting member 20 is radially formed in a shape seen from the axial direction of the swirling flow (a cross-sectional shape broken in a plane perpendicular to the axial direction of the swirling flow), And it is comprised so that it may extend in an axial direction. Thereby, each board | plate material 21 which comprises the refinement | miniaturization promotion member 20 is arrange | positioned so that it may extend in the axial direction and radial direction of a swirl flow, and may collide with a swirl flow. Further, the space in the swirl flow maintaining passage 8 is divided into a plurality of parallel passages 22 extending in parallel along the axial direction of the swirl flow, and these parallel passages 22 are vent holes 20 a of the miniaturization promoting member 20. Are communicated with each other.

  The fine bubble generating apparatus 1 according to the present embodiment has the above-described configuration, and the basic operation thereof is the same as that of the first embodiment. However, in the present embodiment, as shown in FIG. 4, the swirling flow flowing in the swirling flow maintaining passage 8 swirls while passing through the plate members 21 of the miniaturization promoting member 20. As a result, the large bubble B2 that has not been completely refined in the microbubble generation passage 2 is refined when passing through the plate material 21 (vent hole 20a) together with the swirling flow to become a fine bubble B1. In addition, since the bubble B1 that has already been refined in the microbubble generation passage 2 has an outer diameter of 1 μm or less, the bubble B1 flows downstream along the parallel passage 22 without being affected by the miniaturization promoting member 20. .

  In the present embodiment configured as described above, it is possible to obtain substantially the same operational effects as in the first embodiment. In particular, in the present embodiment, the miniaturization promoting member 20 is formed such that the cross-sectional shape is radial and extends in the axial direction of the swirl flow (the gas-liquid flow direction). Without increasing the size, large bubbles can be refined again, and the amount of generated fine bubbles can be improved. Further, by extending the miniaturization promoting member 20 in the radial direction of the swirling flow maintaining passage 8 (swirling flow), the space of the swirling flow maintaining passage 8 can be divided into a plurality of parallel passages 22 with respect to the swirling direction. it can. Thereby, the big bubble which flows with a swirl flow can be collided with the board | plate material 21 from the front, and refinement | miniaturization can be accelerated | stimulated. In addition, since the swirl flow can be divided by the plurality of plate members 21, the coalescence of the bubbles due to the swirl flow can be suppressed, and the once-miniaturized bubbles can be stably held.

  In the first and second embodiments, the case of using the fine bubble generating passage 2 that is conically reduced in diameter is illustrated. However, the present invention is not limited to this. For example, instead of the configuration in which gas and liquid flow in from the tangential direction with respect to the bottom of the fine bubble generation passage 2, a configuration having a blade-shaped swirl flow forming portion or the like may be employed. In the embodiment, the liquid and gas mixture (gas-liquid) is supplied from the single inlet 3 to the fine bubble generation passage 2. However, the present invention is not limited to this, and a liquid inlet and a gas inlet may be separately provided at the bottom of the fine bubble generation passage 2.

  In the first and second embodiments, the cylindrical refinement promoting member 11 and the radial refinement promoting member 20 are used. However, the present invention is not limited to this, and the miniaturization promoting member extends in the swirling direction and the axial direction of the swirling flow in the swirling flow maintaining passage 8, and at least a part of the swirling flow is disposed on the inner peripheral side and the outer peripheral side. Any member that separates into two can be adopted. That is, in the present invention, for example, an arc-shaped refinement promoting member corresponding to a part of the refinement promoting member 11 or a planar refinement promoting member may be used. In addition, as the miniaturization promoting member of the present invention, any member configured to extend in the axial direction and the radial direction of the swirling flow in the swirling flow maintaining passage 8 and to collide with the swirling flow may be adopted. it can. That is, for example, the miniaturization promoting member may be configured by using only a part of the miniaturization promoting member 20 (one plate member 21 or a part of the plate member 21).

  In the first and second embodiments, the cylindrical refinement promoting member 11 and the radial refinement promoting member 20 are individually illustrated. However, the present invention is not limited to this. For example, even if a miniaturization promoting member having a shape obtained by combining a part or the whole of the miniaturization promoting member 11 and a part or the whole of the miniaturization promoting member 20 is employed. Good.

  In the first and second embodiments, the pump 6 is used as the liquid supply means. However, the present invention is not limited to this. For example, a container such as a tank that stores liquid in a pressurized state, or a water supply source such as city water. May be used as the liquid supply means. Moreover, although the case where air bubbles were mixed in water was illustrated in the embodiment, the present invention is not limited to this and can be widely applied to any liquid and gas other than water and air. Furthermore, the fine bubble generating apparatus 1 of the present invention can be used for a bath apparatus that provides a warm bath effect, a parts washing apparatus in a manufacturing process of a factory, a dissolved oxygen enrichment apparatus for the purpose of bioactivation, and the like.

DESCRIPTION OF SYMBOLS 1 Fine bubble generating apparatus 2 Fine bubble production | generation passage 3 Inlet 4 Outlet 5 Gas-liquid supply piping 6 Pump (liquid supply means)
7 Air inlet (gas supply means)
8 Swirling flow maintaining passage 9 Expanded diameter portion 10 Equal diameter portion 11, 20 Refinement promoting member 11a, 20a Vent 12 Inner space 13 Outer space 21 Plate material 22 Parallel passage

Claims (9)

A fine bubble generating passage having a gas-liquid inlet and an outlet, and generating gas bubbles refined in the liquid by allowing the gas-liquid flowing from the inlet to flow out of the outlet in a swirling state. ,
Liquid supply means for supplying a liquid to the inlet of the fine bubble generating passage;
Gas supply means for supplying gas to the inlet of the fine bubble generating passage;
A swirl flow maintaining passage connected to the outlet of the fine bubble generating passage and maintaining a swirling flow of gas and liquid flowing out from the outlet;
A miniaturization promoting member that is provided in the swirl flow maintaining passage and that further contacts the bubbles in the swirl flow state to further refine the bubbles;
A fine bubble generating apparatus.   The fine bubble generating device according to claim 1, wherein the miniaturization promoting member is formed of a porous material or a mesh material.   The said refinement | miniaturization acceleration | stimulation member becomes a structure which extends in the turning direction and axial direction of a swirl flow in the said swirl flow maintenance channel | path, and becomes a structure which isolate | separates at least one part of a swirl flow into an inner peripheral side and an outer peripheral side. The fine bubble generator described in 1.   The fine bubble generating device according to claim 2 or 3, wherein the miniaturization promoting member is configured by a cylindrical body that separates a swirling flow in the swirling flow maintaining passage into an inner peripheral side and an outer peripheral side.   5. The fine structure according to claim 2, wherein the miniaturization promoting member is configured to extend in an axial direction and a radial direction of the swirling flow in the swirling flow maintaining passage and to collide with the swirling flow. Bubble generator.   The said refinement | miniaturization acceleration | stimulation member becomes a structure which divides | segments the space in the said swirl | vortex flow maintenance channel | path into the some path | route extended in parallel along the axial direction of a swirl flow. The microbubble generator described.   The microbubble generator according to any one of claims 2 to 6, wherein the miniaturization promoting member is configured to be radially formed when viewed from the axial direction of the swirling flow and extend in the axial direction.   The fine bubble generation passage is formed in a conical shape whose diameter is reduced from the inflow port toward the outflow port, and the swirl flow maintaining passage is formed in a cylindrical shape having a larger diameter than the outflow port of the fine bubble generation passage. The microbubble generator according to any one of claims 1 to 7, wherein the microbubble generator is configured to be arranged coaxially with the microbubble generation passage.   The swirl flow maintaining passage has one end side connected to the outlet of the fine bubble generation passage, and has a substantially conical diameter-expanded portion whose diameter increases from one end side toward the other end side, and on the other end side of the diameter-expanded portion. The fine bubble generating device according to any one of claims 1 to 8, further comprising a connected cylindrical equal-diameter portion.

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