JP2019089036A - Bubble removal device - Google Patents

Abstract

To provide a bubble removal device capable of effectively and efficiently separating and removing bubbles contained in a fluid.SOLUTION: A plurality of unitized bubble separation and removal devices 1-1 to 1-5 have a common inflow pipe (common inflow port) 5 commonly connected to inflow ports 11-1 to 11-5 which let a bubble removal object liquid flow in, a common outflow pipe (common outflow port) 6 commonly connected to outflow ports 15a-1 to 15a-5 which let a bubble separated and removed object liquid from which the bubble is separated and removed flow out, and a common discharge pipe (common discharge port) 7 commonly connected to gas release pipes 14-1 to 14-5 which discharge a bubble-containing liquid containing the separated and removed bubbles.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a bubble removing apparatus for efficiently separating and removing bubbles contained in a liquid, and more particularly to a bubble removing apparatus for separating and removing bubbles from a liquid by using a spiral flow.

  The need to separate and remove air bubbles from liquids exists in various fields. For example, in a hydraulic machine or the like, if air bubbles are generated in the hydraulic fluid, it may adversely affect a hydraulic device, system or the like using the hydraulic fluid. That is, in the hydraulic system used for the work power transmission of a construction machine etc., if air bubbles are mixed in the working oil which transmits the power, the rigidity of the working oil is lowered and oxidation deterioration of the working oil is promoted. In addition, when air bubbles are mixed in the hydraulic oil, the lubricating characteristics of the hydraulic oil are degraded, and furthermore, the power transmission characteristics and the operating life of the device are reduced. For this purpose, it is necessary to efficiently remove air bubbles contained in the hydraulic oil.

  In addition, in the production process of food and medicine, it may not be preferable if bubbles are mixed in the viscous fluid as the raw material. Also in this case, it is necessary to separate and remove air bubbles from the fluid as the raw material efficiently.

  Therefore, as a device of this type, a device for removing air bubbles in liquid disclosed in Patent Document 1 is known.

  The "defoaming device in liquid" disclosed in Patent Document 1 includes a fluid chamber having at least one inlet at one end and an outlet at the other end, and the inlet is a fluid chamber for the liquid. In the air bubble removing device which generates a tangential flow to the inner wall, the fluid chamber is connected to the first fluid chamber whose diameter gradually decreases continuously from the inlet to the outlet, and the diameter is connected to the first fluid chamber. The second fluid chamber and the second fluid chamber are formed from the end face on the inlet side of the first fluid chamber, and the second fluid chamber gradually and continuously increases toward the other end. An air outlet opening up to the vicinity of the bonding position of the air or a gas air release capillary opening up to the position is provided coaxially with the axial center of the fluid chamber.

Unexamined-Japanese-Patent No. 5-84403

  However, in the "defoaming device in liquid" described in Patent Document 1, there is a limit to the throughput, and when the throughput exceeds this limit, the bubbles contained in the fluid are effectively and efficiently separated and removed. There was a problem that I could not

  Therefore, an object of the present invention is to provide a bubble removing apparatus capable of effectively and efficiently separating and removing bubbles contained in a fluid.

  In order to achieve the above object, the bubble removing apparatus according to the invention of claim 1 has a common inlet connected in common to an inlet for receiving a bubble removal target liquid and a bubble separation removing liquid from which bubbles are separated and removed. A plurality of air bubble separation and removal devices having a common outlet commonly connected to the air outlet and a common outlet commonly connected to an exhaust pipe for discharging a bubble-containing liquid containing separated and removed air bubbles The bubble separation and removal apparatus is configured to generate a swirling flow forming unit that forms a swirling flow of the bubble removal target liquid introduced from the inlet, and a downstream side of the swirling flow formed by the swirling flow forming unit. A first fluid chamber whose diameter gradually decreases and a vent pipe provided on the central axis of the first fluid chamber, one end thereof projecting into the first fluid chamber, and the other end connected to the common discharge port And the downstream side of the first fluid chamber And a second fluid chamber connected to the outlet, wherein the swirling flow forming unit includes an annular flow passage for flowing the bubble removal target liquid introduced from the inlet, and the bubble removal target flowing in the annular flow passage. And a discharge port for discharging the liquid tangentially from at least one portion of the inner peripheral wall of the first fluid chamber.

  The invention according to claim 2 is characterized in that, in the invention according to claim 1, it has a tapered wall which is formed on the periphery of the projecting portion of the exhaust pipe and whose diameter gradually decreases toward the downstream side of the swirling flow.

  The invention according to claim 3 is the pump according to claim 1 or 2, wherein the pump for causing the liquid for bubble removal to flow into the common inlet and the flow rate of the bubble separation and removal liquid flowing out from the common outlet are controlled. And a second valve for controlling the flow rate of the bubbly liquid discharged from the common outlet.

  The invention of claim 4 relates to the pump according to claim 1 or 2, wherein a pump for flowing the liquid to be removed with air bubbles to the common inlet and a plurality of flow rates of the air bubbles removing liquid discharged from the outlet are controlled. It is characterized by comprising a first valve and a plurality of second valves each controlling the flow rate of the bubbly liquid discharged from the exhaust pipe.

  According to the invention of claim 5, in the invention of claim 3, the plurality of air bubble separation and removal devices are circumferentially arranged such that their respective axes are parallel, and the first support member and the second support are provided. It is characterized by being fixed between members.

  In the invention of claim 6, according to the invention of claim 5, the common inlet and the common outlet are provided on the upper surface of the first support member, and the common outlet is provided on the lower surface of the second support member. It is characterized by being provided.

  In the invention of claim 6, according to the invention of claim 5, the common inlet and the common outlet are provided on the upper surface of the first support member, and the common outlet is provided on the lower surface of the second support member. It is characterized by being provided.

  The invention according to claim 7 relates to the invention according to claim 5, wherein the bubble-containing liquid discharged from the outlet flows into the upper part of the plurality of bubble separation and removal devices, and the bubbles contained in the bubble-containing liquid are combined. A bubble increasing device is provided to increase and remove the diameter of the bubbles, and a common discharge port of the liquid from which the bubbles are removed and a float type air vent valve are provided on the upper surface of the bubble increasing device, and the side of the first support member The common inlet and the common outlet are provided on the side of the common support and the side of the second support member.

  The invention according to claim 8 is the invention according to claim 7, wherein the air bubble increasing device comprises a plurality of parallel plate members defining a plurality of mutually communicating areas, and the bubble-containing liquid is used as the plurality of parallel plate members. The diameter of the bubbles contained in the bubble-containing liquid is increased by sequentially leading to the plurality of regions defined by.

  According to the bubble removing apparatus of the present invention, the common inlet connected in common to the inlet through which the bubble removing target liquid flows in and the outlet connected in common to the bubble separating and removing liquid from which the bubbles are separated and removed A plurality of air bubble separation and removal devices having a common outlet, and a common discharge port commonly connected to an exhaust pipe for discharging a bubbly liquid containing separated and removed air bubbles, the air bubble separation and removal device And a swirling flow forming portion that forms a swirling flow of the bubble removal target liquid introduced from the inlet, and a diameter gradually decreasing toward the downstream side of the swirling flow formed by the swirling flow forming portion. An exhaust pipe provided on a central axis of the first fluid chamber and the first fluid chamber, one end thereof projecting into the first fluid chamber, and the other end connected to the common discharge port, and the first fluid chamber A downstream side of the second And the annular flow passage for flowing the bubble removal target liquid introduced from the inlet, and the first fluid chamber for the bubble removal target liquid flowing in the ring passage. Since the discharge port is provided to discharge in the tangential direction from at least one portion of the inner peripheral wall of the above-mentioned structure, it is possible to effectively and efficiently remove the air bubbles contained in the fluid.

FIG. 1 is a system configuration diagram of a bubble removal apparatus according to a first embodiment of the present invention. FIG. 2 is a side sectional view of an example of the unitized air bubble separation and removal apparatus used in the system configuration shown in FIG. FIG. 3 is a cross-sectional view of the air bubble separation and removal apparatus shown in FIG. FIG. 4 is a side sectional view for explaining the operation of the air bubble separation and removal apparatus used in the air bubble separation and removal apparatus shown in FIG. FIG. 5 is a side sectional view of another example of the unitized bubble separation and removal apparatus used in the bubble separation and removal apparatus shown in FIG. 6 is a cross-sectional view of the air bubble separation and removal apparatus shown in FIG. FIG. 7 is a perspective view showing an example of the appearance of the air bubble removing device shown in FIG. FIG. 8 is a top view and a side view of the bubble removal device shown in FIG. FIG. 9 is a perspective view showing an example of the appearance of a bubble removing apparatus according to a second embodiment of the present invention. FIG. 10 is a top view and a side view of the bubble removing device shown in FIG. FIG. 11 is a system configuration diagram of a bubble removal device according to a third embodiment of the present invention.

  Hereinafter, an embodiment of a bubble removing apparatus according to the present invention will be described in detail with reference to the attached drawings.

  FIG. 1 is a system configuration diagram of a bubble removing apparatus 100 according to a first embodiment of the present invention.

  The bubble removing apparatus 100 according to the first embodiment separates and removes bubbles from the bubble removing target liquid stored in the tank 110, and is commonly connected to the inlets 11-1 to 11-5 for receiving the bubble removing target liquid. Common inflow pipe (common inflow port) 6 commonly connected to the common inflow pipe (common inflow port) 5 and the outflow ports 15a-1 to 15a-5 from which the bubble separated and removed liquid from which the bubbles are separated and removed is output. , And a plurality of units having a common discharge pipe (common discharge port) 7 commonly connected to the discharge pipes 14-1 to 14-5 for discharging the bubble-containing liquid containing air bubbles separated and removed. A bubble separation and removal apparatus 1-1 to 1-5 is provided.

  The common inflow port 5 is supplied with the bubble removal target liquid pumped out of the tank 110 by the pump 2.

  The bubble separation and removal liquid from which the bubbles flowing out from the common outlet 6 have been separated and removed is controlled by the control valve 3 and returned to the tank 110. Further, the bubble-containing liquid discharged from the common discharge port 7 is returned to the tank 110 with its flow rate controlled by the control valve 4.

  Here, the bubble-containing liquid discharged from the common outlet 7 may be configured to be separated without being returned directly to the tank 110, and the bubbles may be separated and discharged using a bubble increasing device described later. After that, it may be configured to be returned to the tank 110.

  FIG. 2 is a side sectional view of an example of the unitized bubble separation and removal apparatus 1-1 to 1-5 (hereinafter referred to as the bubble separation and removal apparatus 1) used in the system configuration shown in FIG.

  In FIG. 2, the unitized bubble separation and removal apparatus 1 uses the swirling flow of the bubble removal target liquid P0 introduced from the inlet 11 to remove the bubble removal target liquid P0 from the first bubbles. The air bubbles are removed from the air bubble removal target liquid P0 by separating into the second liquid (air bubble separation and removal liquid) P1 and the second liquid (air bubble containing liquid) P2 containing air bubbles.

  The bubble separation and removal apparatus 1 includes a swirling flow forming unit 12 that forms a swirling flow of a bubble removal target liquid P0 from a bubble removal target liquid P0 introduced from an inlet 11, a first fluid chamber 13, and a first A second fluid chamber 15 provided on the downstream side of the fluid chamber 13 and a flue 14 whose one end is open in the first fluid chamber 13 are provided.

  Here, the swirling flow forming unit 12 includes an annular flow passage 121 formed along the outer periphery of the swirling flow forming unit 12 and discharge ports 122 provided at two places connected to the annular flow passage 121. Configured

  The first fluid chamber 13 is a space surrounded by a frusto-conical inner peripheral wall 13a whose diameter gradually decreases toward the downstream side, and the bubble removal target liquid P0 formed by the swirling flow forming unit 12 is It flows in the space surrounded by the inner peripheral wall 13a.

  The second fluid chamber 15 has a cylindrical shape, one end of which is connected to the downstream side of the first fluid chamber 13, and the other end of which is the first liquid P1 from which air bubbles have been removed by the air bubble removing device 100. An outlet 15a is formed to flow out.

  The exhaust pipe 14 is provided on the central axis of the first fluid chamber 13, and at one end, an opening 14a which protrudes and opens into the first fluid chamber 13 is provided, and at the other end, the air bubble separation and removal device An outlet 14 b is formed to discharge the second liquid P 2 containing the air bubbles removed at 100.

  Next, with reference to FIG. 3 and FIG. 4, the operation of the air bubble separation and removal apparatus 1 of this embodiment will be described.

  3 is a cross-sectional view of the air bubble separation and removal apparatus 1 shown in FIG. 2 taken along the line A-A, and FIG. 4 is a side cross sectional view for explaining the operation of the air bubble separation and removal apparatus 1 shown in FIGS. .

  In FIG. 3 and FIG. 4, the bubble removal target liquid P0 introduced from the inflow port 11 flows in the annular flow channel 121 of the swirling flow forming portion 12 and is connected to the annular flow channel 121 as shown by the arrow in FIG. The bubble removal target liquid P0 is discharged into the first fluid chamber 13 along the tangential direction of the peripheral wall of the first fluid chamber 13 from the discharge port 122. Thereby, the swirling flow F of the bubble removal target liquid P0 is formed in the first fluid chamber 13.

  The swirling flow F of the bubble removal target liquid P0 formed in the first fluid chamber 13 is surrounded by the frustoconical inner peripheral wall 13a whose diameter gradually decreases toward the downstream side of the first fluid chamber 13 Flow through the space.

  Here, due to the centrifugal force generated by the spiral flow F of the bubble removal target liquid P0, the oil containing no bubbles is directed to the peripheral wall 13a side of the first fluid chamber 13, and the bubbles are the first as shown by B in FIG. The fluid is collected around the opening 14 a of the exhaust pipe 14 in the fluid chamber 13 of FIG.

  The bubbles B collected around the opening of the discharge pipe 14 in the first fluid chamber 13 by the spiral flow F of the bubble removal target liquid P0 formed by the swirling flow forming unit 12 are on the second fluid chamber 15 side. The second liquid P 2 containing the air bubble B is discharged from the discharge port 14 b at the other end of the exhaust pipe 14 by the back pressure applied thereto.

  On the other hand, the second liquid P 1 whose air bubbles have been removed in the first fluid chamber 13 by the exhaust pipe 14 flows out of the outlet 15 a through the second fluid chamber 15.

  The air bubble removal apparatus 100 of the first embodiment shown in FIG. 1 is configured by connecting in parallel five unitized air bubble separation and removal apparatuses 1-1 to 1-5 of the above configuration, and such a configuration According to the invention, it is possible to obtain about five times the throughput of one air bubble separation and removal apparatus 1. The number of unitized bubble separation and removal apparatuses 1 constituting the bubble removal apparatus 100 is not limited to five, and various processing amounts can be obtained by increasing or decreasing the number of unitized bubble separation and removal apparatuses 1. It can correspond.

  FIG. 5 is a side sectional view of another example of the unitized bubble separation and removal apparatus used in the bubble separation and removal apparatus shown in FIG. 1, and FIG. 6 is an A side of the bubble separation and removal apparatus 1A shown in FIG. It is -A sectional view.

  The air bubble separation and removal apparatus 1A shown in FIGS. 5 and 6 differs from the air bubble separation and removal apparatus 1 shown in FIGS. 2 to 4 in that a tapered wall 16 is formed at the periphery of the protrusion of the exhaust pipe.

  In the air bubble separation and removal apparatus 1A shown in FIGS. 5 and 6, the first fluid chamber 13 is surrounded by the frusto-conical inner peripheral wall 13a and the tapered wall 16 whose diameter gradually decreases toward the downstream side. The bubble removal target liquid P0 formed of the space and formed by the swirling flow forming portion 12 flows into the space surrounded by the inner peripheral wall 13a and the tapered wall 16.

  In the air bubble removing device 1A, the presence of the tapered wall 16 makes it possible to collect the air bubbles B more efficiently around the opening of the exhaust pipe 14 as compared with the case where the tapered wall 16 is not provided. The rate can be increased and the pressure drop can be reduced.

  This is because the tapered wall 16 eliminates useless space through which the spiral flow F of the bubble removal target liquid P0 formed by the swirl flow forming unit 12 flows, so that the turbulent flow of the bubble removal target liquid P0 in the first fluid chamber 13 Is substantially reduced, and it is considered that this is because the attenuation of the flow velocity of the bubble removal target liquid P0 is reduced. The other configuration is the same as that of the air bubble separation and removal apparatus 1 shown in FIGS. 2 to 4.

  7 is a perspective view showing an example of the appearance of the air bubble removal apparatus 100 adopting the system configuration shown in FIG. 1, and FIG. 8A is a top view of the air bubble removal apparatus 100 shown in FIG. And FIG. 8 (B) is a side view of the bubble removal apparatus 100 shown in FIG.

  In the bubble removal apparatus shown in FIGS. 7 and 8, the unitized bubble separation and removal apparatus 1 or 1A shown in FIG. 2 to FIG. 4 or FIG. 5 to FIG. It arranges on top and is fixed and comprised between the 1st support member 8a and the 2nd support member 8b.

  The common inlet 5 and the common outlet 7 are provided on the upper surface of the first support member 8a, and the common outlet 6 is provided on the lower surface of the second support member 8b.

  According to such a configuration, the plurality of air bubble separation and removal devices 1 or 1A can be disposed in a narrow space, and the plurality of air bubble separation and removal devices 1 or 1A is configured to support the first support member 8a and the second support. Since it is fixed between the members 8b, various throughputs can be obtained by changing the number of the bubble separation and removal apparatus 1 or 1A disposed between the first support member 8a and the second support member 8b. It can correspond to

  Moreover, according to this configuration, the resistance and pressure of the inflow port 11 of the bubble separation and removal apparatus 1 or 1A become equal, and uniform liquid flow can be secured in the plurality of bubble separation and removal apparatus 1 or 1A, so stable performance is obtained. be able to.

  FIG. 9 is a perspective view showing an example of the appearance of a bubble removing apparatus 200 according to a second embodiment of the present invention, and FIG. 10 (A) is a top view of the bubble removing apparatus 200 shown in FIG. (B) is a side view of the air bubbles removal device 200 shown in FIG.

  In the bubble removal apparatus 200 of the second embodiment, the bubble-containing liquid discharged from the outlet 14b of the plurality of bubble separation and removal devices 1 or 1A flows into the upper portion of the plurality of bubble separation and removal devices 1 or 1A. A bubble increasing device 9 is provided which increases and removes the diameter of the bubbles by bonding of the bubbles contained in the bubble-containing liquid.

  Further, a common discharge port 7 of the liquid from which the bubbles increased by the bubble increasing device 9 have been removed and a float type air vent valve 10 are provided on the upper surface of the bubble removing device 200, and the side portion of the first support member 8a is provided. A common inlet 5 is provided, and a common outlet 6 is provided on the side of the second support member 8b.

  The bubble intensifying device 9 includes a plurality of parallel plate members 9a defining a plurality of mutually communicating areas, and a plurality of bubble-containing liquids discharged from the outlet 14b of the plurality of bubble separating and removing devices 1 or 1A are arranged in parallel. The diameter of the bubbles contained in the bubble-containing liquid is increased by sequentially guiding the plurality of regions defined by the plate material 9a. The increased air bubbles are vented from the float air vent valve 10 on the top surface of the air bubble remover 200.

  FIG. 11 is a system configuration diagram of a bubble removal apparatus 300 according to a third embodiment of the present invention.

  The system configuration shown in FIG. 11 corresponds to the control valve 3 corresponding to the outlets 15a-1 to 15a-5 of the bubble separation and removal apparatuses 1-1 to 1-5 instead of the control valve 3 shown in FIG. Are different from the system configuration diagram shown in FIG. 1 in that the control valves 4-1 to 4-5 are provided and the control valves 4-1 to 4-5 are provided corresponding to the exhaust pipes 14-1 to 14-5. The other configuration is the same as the system configuration diagram of FIG.

  The bubble removing apparatus 300 according to the third embodiment does not have the configuration as shown in FIGS. 7 to 8 or 9 to 10, and the bubble separating and removing apparatus 1-1 to 1-5 bubble separating and removing apparatus 1-1 It is suitable in the case where it takes the structure which connects 1-5 in parallel.

  Although the above is an example of a representative embodiment of the present invention, the present invention is not limited to the above embodiment and the embodiments shown in the drawings, and can be appropriately modified without departing from the scope of the invention. It is possible.

  For example, in the above embodiment, the swirling flow F of the bubble removal target liquid P0 is formed by discharging the bubble removal target liquid P0 into the first fluid chamber 13 from the discharge ports 122 provided in two places. However, the liquid for bubble removal is discharged into the first fluid chamber from the discharge port provided at one or three or more places, so that the swirl flow of the liquid for bubble removal is formed. It is also good.

  Further, the tapered wall 16 formed on the periphery of the projecting portion of the exhaust pipe 14 into the first fluid chamber 13 has a tapered shape in which the diameter gradually decreases toward the second fluid chamber 15. It is not limited to the shapes described in FIGS. 1 and 2.

1-1 to 1-5 air bubble separation and removal device 2 pump 3 control valve 4 control valve 5 common inlet pipe (common inlet)
6 Common outlet pipe (common outlet)
7 common discharge port 8a first support member 8b second support member 9 air bubble increasing device 11, 11-1 to 11-5 inflow port 12 swirling flow forming portion 13 first fluid chamber 13a inner circumferential wall 14, 14-1 14 to 14 Exhaust pipe 14a Opening 14b Outlet 15 Second fluid chamber 15a, 15a-1 to 15a-5 Outlet 16 Taper wall 10 First unit 10a First flange 10b Second flange 20 Second Unit 20a Third flange 30 Third unit 30a Fourth flange 40a Herrule clamp 40b Ferrule clamp 100 Bubble separation and removal device 110 Tank 200 Bubble separation and removal device 300 Bubble separation and removal device P0 Bubble removal target liquid P1 First liquid (Air bubble separation removal liquid)
P2 Second liquid (bubble-containing liquid)

Claims (8)

And a common outlet commonly connected to an inlet for introducing a bubble removal target liquid, and a common outlet commonly connected to an outlet for discharging a bubble separating and removing liquid from which bubbles are separated and removed. A plurality of air bubble separation and removal devices having a common discharge port commonly connected to an exhaust pipe for discharging the air bubble-containing liquid containing air bubbles separated and removed;
The air bubble separation and removal device is
A swirl flow forming unit that forms a swirl flow of the bubble removal target liquid introduced from the inlet;
A first fluid chamber whose diameter gradually decreases toward the downstream side of the swirling flow formed by the swirling flow forming portion;
An exhaust pipe provided on a central axis of the first fluid chamber, one end of which protrudes into the first fluid chamber, and the other end of which is connected to the common outlet;
A second fluid chamber provided downstream of the first fluid chamber and connected to the outlet;
Equipped with
The swirling flow forming unit is
An annular flow passage for flowing the bubble removal target liquid introduced from the inlet;
A discharge port which discharges the liquid to be removed in the annular flow passage tangentially from at least one portion of the inner peripheral wall of the first fluid chamber;
A bubble removing device characterized by comprising. A tapered wall formed on the periphery of the projecting portion of the exhaust pipe, the diameter gradually decreasing toward the downstream side of the swirling flow;
The bubble removing device according to claim 1, comprising: A pump for causing the liquid to be removed from the air bubbles to flow into the common inlet;
A first valve for controlling the flow rate of the bubble separation and removal liquid flowing out from the common outlet;
A second valve for controlling the flow rate of the bubble-containing liquid discharged from the common outlet;
The air bubble removing device according to claim 1 or 2, further comprising: A pump for flowing the bubble removal target liquid to the common inlet;
A plurality of first valves for controlling the flow rate of the bubble separating and removing liquid flowing out from the outlet;
A plurality of second valves each controlling the flow rate of the bubbly liquid discharged from the exhaust pipe;
The air bubble removing device according to claim 1 or 2, further comprising: The plurality of air bubble separation and removal devices are
4. A bubble removing apparatus according to claim 3, wherein the respective axes are arranged on a circumference so as to be parallel and fixed between the first supporting member and the second supporting member. .   The air bubble according to claim 5, wherein the common inlet and the common outlet are provided on the upper surface of the first support member, and the common outlet is provided on the lower surface of the second support member. Removal device. A bubble-enhancing device for flowing the bubble-containing liquid discharged from the outlet into the upper part of the plurality of bubble separation and removal devices, and increasing the diameter of the bubbles by bonding of the bubbles contained in the bubble-containing liquid Provide
A common outlet for the liquid from which air bubbles have been removed and a float type air vent valve are provided on the upper surface of the air bubble increasing device, and the common inlet on the side of the first support member, the side of the second support member The air bubble removing device according to claim 5, wherein the common outlet is provided. The air bubble intensifying device comprises a plurality of parallel plate members defining a plurality of mutually communicating areas;
Equipped with
The bubble removing method according to claim 7, wherein the diameter of the bubbles contained in the bubble-containing liquid is increased by sequentially guiding the bubble-containing liquid to the plurality of regions defined by the plurality of parallel plate members. apparatus.

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