JP5493153B2 - Microbubble generating pump, moving blade for microbubble generating pump and stationary blade for microbubble generating pump - Google Patents

Description

  The present invention relates to a microbubble generating pump based on a novel principle, a moving blade for a microbubble generating pump used for the microbubble generating pump, and a stationary blade for a microbubble generating pump.

Microbubbles are fine bubbles having a bubble diameter of generally 10 to several tens of μm at the time of generation, and are extremely small compared to bubbles having a diameter of several millimeters that are normally generated in water. Since microbubbles are extremely small in this way, they have the property of adsorbing fine dust and floating on the surface of the water, and are applied to various processes such as washing of marine products and water purification.
Conventionally, swirl type microbubble generators are often used as the microbubble generators. As this swirling flow type microbubble generator, a device that injects gas into the center of a swirling flow of liquid and generates microbubbles using centrifugal separation is known (for example, International Publication No. 01/097958). Issue pamphlet). In addition, a swirl type microbubble generator using a vortex breakdown phenomenon is also known (see, for example, Japanese Patent Application Laid-Open No. 2005-169286 and International Publication No. 06/075452).
In the above-described conventional swirling flow type microbubble generator, in order to obtain a desired flow rate while generating a swirling flow of liquid, it is necessary to apply pressure to the liquid supplied to the pipe line. A pump, especially a pump with a high head, is indispensable. A turbo pump is often used as a pump having a high head.
However, according to the study of the present inventor, when viewed in the entire system composed of the swirling flow type microbubble generator and the turbo pump, a lot of energy is wasted and the energy efficiency is low. was there.
In particular, when the swirl type microbubble generator is used over a wide range and for a long time for the purpose of purifying the water area, improving the energy efficiency of the generation of microbubbles is an important issue in its operation.
Therefore, the problem to be solved by the present invention is a microbubble generating pump capable of generating microbubbles with high energy efficiency, a moving blade for a microbubble generating pump used for the microbubble generating pump, and a microbubble generating pump It is to provide a stationary blade.
Another problem to be solved by the present invention is a microbubble generating pump capable of generating microbubbles with high energy efficiency even with a small motor, a moving blade for a microbubble generating pump used in the microbubble generating pump, and a microblade. It is to provide a stationary blade for a bubble generating pump.

According to the study by the present inventor, when a turbo pump is connected to the swirl type micro bubble generator, if the swirl type micro bubble generator and the turbo pump are analyzed as a unit, the operation of the turbo type pump is determined. Since the swirl flow generated by the blades is stopped by the stationary blade and the swirl flow is generated again by the swirl flow type microbubble generator, energy wasted and energy efficiency was reduced.
In view of this, the present inventor conducted extensive research to improve the energy efficiency of microbubble generation, and as a result, under the new idea completely different from the conventional one, generation of liquid swirl, liquid transport, and vortex It came to devise a new pump with the function of generating microbubbles by collapse.
That is, in order to solve the above problems, the present invention provides:
Inside the casing, it has a moving blade, a stationary blade and a vortex breakdown nozzle arranged sequentially coaxially from the suction port toward the discharge port,
Supplying the liquid sucked from the suction port to the moving blade to generate a swirling flow;
The swirling flow is supplied to the stationary blade, a gas is introduced into the center of the swirling flow at the stationary blade or the latter stage of the stationary blade, and the swirling flow into which the gas has been introduced is supplied to the vortex breaking nozzle to be swirled. It is a microbubble generating pump that generates microbubbles by causing collapse and discharges them from the discharge port together with the liquid.
Here, in order to satisfy the vortex breakdown generation condition, the moving blade needs to have a shape that generates a swirling flow velocity that is twice or more the flow velocity in the central axis direction. A moving blade typically includes a cylindrical main body and a plurality of blades provided on the outer peripheral surface of the cylindrical main body, and the plurality of blades run vertically on the outer peripheral surface of the cylindrical main body. The cylindrical body is provided so as to bend from the one end portion on the liquid outlet side toward the other end portion. A plurality of blades having the same shape are provided at equal intervals on the outer peripheral surface of the cylindrical main body. In this case, the angle with respect to the circumferential direction (tangential direction) of the moving blade at the edge on the other end side of the plurality of blades is preferably such that the liquid flow supplied to the moving blade does not separate from the plurality of blades. Chosen. Specifically, for example, when the angle with respect to the circumferential direction of the moving blade at the edge on the other end side of the plurality of blades is θ _I , the moving blade as viewed from the rotating coordinate system rotating with the moving blade The absolute value of the angle of attack with respect to the flow of the supplied liquid | θ _I −α _I | (where α _I = tan ⁻¹ (U _I / RΩ), U _I represents the moving blade as viewed from the stationary coordinate system The liquid suction velocity, R is the moving blade radius, and Ω is the moving blade angular velocity) are selected to be greater than 0 degrees and 20 degrees or less, but are not limited thereto. In addition, the angle θ _{F with} respect to the circumferential direction of the moving blade at the edge on the one end side of the plurality of blades is preferably 60 degrees or more and 90 degrees or less, and more preferably 85 degrees or more and 90 degrees or less. However, the present invention is not limited to this.
A stationary blade typically includes a cylindrical main body and a plurality of wings provided on the outer peripheral surface of the cylindrical main body, and the plurality of wings run vertically on the outer peripheral surface of the cylindrical main body. The cylindrical body is provided so as to bend as it goes from the one end to the other end on the side where the swirling flow is supplied. A plurality of blades having the same shape are provided at equal intervals on the outer peripheral surface of the cylindrical main body. In this case, the angle with respect to the circumferential direction of the stationary blade at the edge on the one end side of the plurality of blades is preferably selected so that the swirl flow supplied from the moving blade does not separate from the plurality of blades. Specifically, for example, the angle with respect to the circumferential direction of the stationary blade at the edge on the one end side of the plurality of blades is φ _I , and the ejection angle of the liquid from the moving blade when viewed from the stationary coordinate system is α _F When α _F > φ _I , the angle of attack (α _F −φ _I ) with respect to the flow of the liquid supplied to the stationary blade is selected to be greater than 0 degree and 20 degrees or less, and φ _I > α _In the case of _F, the angle of attack (φ _I −α _F ) with respect to the flow of the liquid supplied to the stationary blade is selected to be greater than 0 degree and 20 degrees or less. Preferably, the plurality of blades are configured such that no gap appears when projected in the direction of the central axis of the stationary blade. Specifically, for example, when the plurality of blades are projected in the direction of the central axis of the stationary blade, Configured to overlap each other.
The introduction of the gas into the swirling flow in the stationary blade or the latter stage of the stationary blade can be performed by various methods. In one typical example, the stationary blade is an injection hole provided at the above-mentioned other end of the cylindrical body and the other end of the cylindrical body, for example, at the other end. The air supply hole and the injection hole communicate with each other through a passage provided in the cylindrical main body. Typically, a hole is provided in a portion of the casing corresponding to the air supply hole provided in one blade, and a gas introduction pipe is connected to the hole from the outside.
The vortex breakdown nozzle typically has a contraction part and a vortex breakdown part, and microbubbles are generated from the vortex breakdown part by supplying a swirl flow into which gas has been introduced. Typically, the vortex breakdown portion has a first portion having a cylindrical shape and a second portion having a shape extending toward the outlet, and the inner peripheral surface of the first portion and the end surface of the second portion. when the angle theta ₀ to preparative forms, is 0 ° <theta _{0 <180} °, but an inner circumferential surface of the first portion and the end face of the second portion are connected smoothly, limited to It is not something. θ ₀ is preferably 90 degrees <θ ₀ <180 degrees, for example, about 100 degrees. Typically, the cross-sectional area of the contracted flow part gradually decreases toward the vortex breakdown part (or the contraction part squeezes toward the vortex breakdown part), and The boundary portion (or connection portion) has the same cross-sectional shape as the vortex breakdown portion. Since the inner peripheral surface of the first portion and the end surface of the second portion are smoothly connected, a swirl flow can be attached to the end surface of the second portion which is the ejection surface of the vortex breakdown nozzle. The effect makes it possible to efficiently cause vortex breakdown. Here, the Coanda effect refers to the property of a fluid that changes the flow direction along the placed object when the object is placed in the flow. The vortex breakdown nozzle may be provided separately from the casing and attached to the casing, or the casing itself may be processed into the same shape as the inner peripheral surface of the vortex breakdown nozzle.
The microbubble generating pump may have another moving blade and another stationary blade arranged sequentially coaxially from the suction port toward the discharge port on the suction port side of the moving blade. This configuration is suitable for obtaining a high-lift microbubble generating pump. In this case, the other moving blade typically includes a cylindrical main body and a plurality of wings provided on the outer peripheral surface of the cylindrical main body, and the plurality of the wings is a cylindrical main body. The cylindrical body is provided so as to bend as it goes from the one end on the liquid outlet side to the other end. The plurality of blades having the same shape as each other are provided at equal intervals on the outer peripheral surface of the cylindrical main body. The other stationary blade is typically composed of a cylindrical main body and a plurality of wings provided on the outer peripheral surface of the cylindrical main body. The outer peripheral surface is provided so as to run longitudinally in the direction of the central axis of the other stationary blade. The plurality of blades having the same shape as each other are provided at equal intervals on the outer peripheral surface of the cylindrical main body. The original moving blade typically includes a cylindrical main body and a plurality of wings provided on the outer peripheral surface of the cylindrical main body, and the plurality of wings are formed of the cylindrical main body. It is provided so as to bend in the longitudinal direction on the outer peripheral surface and from the one end portion on the liquid outlet side of the columnar main body toward the other end portion. The original stationary vane is typically composed of a cylindrical main body and a plurality of wings provided on the outer peripheral surface of the cylindrical main body. It is provided so as to bend along the outer peripheral surface as it goes from the one end portion on the liquid inflow side to the other end portion of the cylindrical main body.
In this microbubble generating pump, the moving blade may be configured in the same manner as the moving blade of the mixed flow pump. Specifically, in this case, for example, the moving blades are provided on a frustoconical body whose cross-sectional area increases in a direction from the suction port to the discharge port of the microbubble generating pump, and on the outer peripheral surface of the frustoconical body. The plurality of wings are arranged so as to vertically cross the outer peripheral surface of the frustoconical main body and from one end of the frustoconical main body to the other end of the liquid inflow side. Although it is provided to bend as it goes, it is not limited to this.
In this microbubble generating pump, a pressure blocking nozzle provided opposite to the vortex breakdown nozzle and coaxially may be provided on the downstream end face side of the vortex breakdown nozzle. In this case, a gap is formed between the downstream end face of the vortex breaking nozzle and the upstream end face of the pressure blocking nozzle, and the gap is spaced radially from the central axis of the vortex breaking nozzle and the pressure blocking nozzle. The portion of the pressure blocking nozzle that faces the outlet of the vortex breaking nozzle is cut off from the downstream side of the pressure blocking nozzle at the center of the swirling flow that exits from the outlet of the vortex breaking nozzle. The portion of the pressure blocking nozzle that faces the outlet of the vortex breakdown nozzle is configured not to penetrate the outlet of the vortex breakdown nozzle. The microbubbles ejected from the outlet of the vortex breaking nozzle go to the outside through a gap between the downstream end face of the vortex breaking nozzle and the upstream end face of the pressure blocking nozzle. From the viewpoint of minimizing the pressure in the air column, in other words, maximizing the suction pressure, the apex angle of the downstream end face of the vortex breakdown nozzle is θ _VB , and the apex angle of the upstream end face of the pressure blocking nozzle is θ _SU In this case, θ _SU ≦ θ _VB is preferable, and Δθ≡θ _VB −θ _SU = 0 to 20 ° is more preferable. In addition, from the viewpoint of minimizing the pressure in the air column, in other words, maximizing the suction pressure, the diameter of the outlet at the downstream end face of the vortex breakdown nozzle is set to D _e , the center of the vortex breakdown nozzle and the pressure blocking nozzle when the distance between the vortex breakdown nozzle and pressure shut-off nozzle is t on an axis, it is preferable that t is approximately D _{e /} 4. The exit of the vortex breaker nozzle is typically cylindrical, in which case the diameter _De is constant over the entire length of the cylindrical outlet, but is not limited thereto, of it may be changed diameter D _e in the length direction.
The pressure blocking nozzle is accommodated in the casing, and the microbubbles ejected from the outlet of the vortex breakdown nozzle pass through the gap, and further on the outer peripheral surface of the casing and the pressure blocking nozzle on the central axis of the pressure blocking nozzle. You may comprise so that it may discharge | release outside through the space between several groove | channels provided in parallel. Alternatively, instead of forming a groove on the outer peripheral surface of the pressure blocking nozzle, a portion of the pressure blocking nozzle adjacent to the outer peripheral surface of the pressure blocking nozzle is parallel to the central axis of the pressure blocking nozzle. A plurality of holes may be provided. Alternatively, the pressure blocking nozzle has a shape that swells on the downstream side, and the pressure blocking nozzle has a gap adjacent to the inner wall of the casing and the downstream end face of the pressure blocking nozzle. And a plurality of holes that merge with each other on the downstream end face of the pressure blocking nozzle, and the microbubbles ejected from the outlet pass through the gap, and further for pressure blocking You may comprise so that it may discharge | release outside through said several hole of a nozzle. The aspect ratio (length / inner diameter) of these grooves or holes is preferably greater than 1.
In this microbubble generating pump, vortex breakdown may be caused in the portion between the suction port of the casing and the moving blade. For this purpose, for example, the casing is configured so that the cross-sectional area increases toward the rotor blade after the cross-sectional area of the casing decreases from the suction port toward the rotor blade to the minimum cross-sectional area. That's fine. In this case, gas is introduced from the outside into the casing between the suction port and the moving blade, preferably the portion having the minimum cross-sectional area.
The liquid that generates the microbubbles may be basically any type, specifically, for example, water (including hot water), various organic solvents (alcohol, acetone, toluene, etc.), Liquid fuels such as oil and gasoline.
The gas supplied to the center of the swirling flow and the gas introduced from the outside into the casing in the portion between the suction port and the rotor blade may be basically any type, specifically, For example, air, oxygen, ozone, hydrogen, argon and the like.
In addition, this invention
Inside the casing, it has a moving blade, a stationary blade and a vortex breakdown nozzle arranged sequentially coaxially from the suction port toward the discharge port,
Supplying the liquid sucked from the suction port to the moving blade to generate a swirling flow;
The swirling flow is supplied to the stationary blade, a gas is introduced into the center of the swirling flow at the stationary blade or the latter stage of the stationary blade, and the swirling flow into which the gas has been introduced is supplied to the vortex breaking nozzle to be swirled. A microbubble generating pump moving blade used in a microbubble generating pump that generates microbubbles by causing collapse and discharges the liquid from the discharge port together with the liquid,
It consists of a cylindrical main body and a plurality of wings provided on the outer peripheral surface of the cylindrical main body, and the plurality of wings cut vertically on the outer peripheral surface of the cylindrical main body and the cylindrical shape. The angle of the main blade of the plurality of blades with respect to the circumferential direction of the moving blade is set to bend from the one end portion on the liquid outlet side toward the other end portion. The flow of the liquid supplied to the moving blade is selected so as not to separate from the plurality of blades.
In addition, this invention
Inside the casing, it has a moving blade, a stationary blade and a vortex breakdown nozzle arranged sequentially coaxially from the suction port toward the discharge port,
Supplying the liquid sucked from the suction port to the moving blade to generate a swirling flow;
The swirling flow is supplied to the stationary blade, a gas is introduced into the center of the swirling flow at the stationary blade or the latter stage of the stationary blade, and the swirling flow into which the gas has been introduced is supplied to the vortex breaking nozzle to be swirled. A microbubble generating pump stationary blade used for a microbubble generating pump that generates microbubbles by causing collapse and discharges the liquid from the discharge port together with the liquid,
It consists of a cylindrical main body and a plurality of wings provided on the outer peripheral surface of the cylindrical main body, and the plurality of wings cut vertically on the outer peripheral surface of the cylindrical main body and the cylindrical shape. The angle of the plurality of blades with respect to the circumferential direction of the stationary blade at the edge on the one end portion side is provided so as to bend from the one end portion on the side to which the swirl flow is supplied toward the other end portion. The swirl flow supplied from the moving blade is selected so as not to separate from the plurality of blades.
In the above-described invention of the moving blade for the microbubble generating pump and the stationary blade for the microbubble generating pump, what has been described in relation to the invention of the microbubble generating pump is valid.
Furthermore, this invention
Inside the casing, it has a moving blade and a vortex breakdown nozzle sequentially arranged coaxially from the suction port toward the discharge port,
A suction plate having a through hole in the center is provided coaxially with the moving blade and the vortex breaking nozzle so as to close the suction port at the suction port of the casing,
The moving blade comprises a vortex impeller having a diameter smaller than the inner diameter of the casing,
Supplying the liquid sucked from the through hole of the suction plate provided in the suction port to the vortex impeller to generate a swirl flow,
A gas is introduced into the center of the swirling flow, and the swirling flow into which the gas has been introduced is supplied to the vortex breakdown nozzle to cause vortex breakdown, thereby generating microbubbles and discharging the liquid together with the liquid from the discharge port. This is a microbubble generating pump.
This microbubble generating pump has a stationary blade between the vortex impeller and the vortex breakdown nozzle depending on the application.
In the invention of the microbubble generating pump, what has been described in relation to the invention of the microbubble generating pump is valid as long as it is not contrary to the nature.
According to the present invention, it is possible to realize a microbubble generating pump capable of generating microbubbles with high energy efficiency. This microbubble generating pump is also suitable for use over a wide range and for a long time, for the purpose of purifying water areas, for example. The microbubble generation pump is also suitable for generating microbubbles with a small motor.

FIG. 1 is a sectional view showing a microbubble generating pump according to a first embodiment of the present invention.
FIG. 2 is a schematic diagram showing portions of a moving blade and a stationary blade of the microbubble generating pump according to the first embodiment of the present invention.
FIG. 3 is a schematic diagram showing portions of a moving blade and a stationary blade of the microbubble generating pump according to the first embodiment of the present invention.
FIG. 4 is a schematic diagram showing portions of a moving blade and a stationary blade of the microbubble generating pump according to the first embodiment of the present invention.
FIG. 5 is a schematic diagram for explaining the angle of attack Δα of the liquid inflow end of the blade of the moving blade of the microbubble generating pump according to the first embodiment of the present invention.
FIG. 6 is a sectional view showing a stationary blade of the microbubble generating pump according to the first embodiment of the present invention.
FIG. 7 is a perspective view showing a stationary blade of the microbubble generating pump according to the first embodiment of the present invention.
FIG. 8 is a developed view showing a specific example of the moving blade of the microbubble generating pump according to the first embodiment of the present invention.
FIGS. 9A and 9B are schematic diagrams showing a design example of a stationary blade of the microbubble generating pump according to the first embodiment of the present invention.
FIG. 10 is a sectional view showing a vortex breakdown nozzle of the microbubble generating pump according to the first embodiment of the present invention.
FIG. 11 is a schematic diagram showing an example in which the microbubble generating pump according to the first embodiment of the present invention is applied to water purification of a pond.
FIG. 12 is a sectional view showing a microbubble generating pump according to a second embodiment of the present invention.
FIG. 13 is a schematic diagram showing a moving blade of a microbubble generating pump according to a third embodiment of the present invention.
14A and 14B are schematic diagrams showing a moving blade of a microbubble generating pump according to a third embodiment of the present invention.
FIG. 15 is a sectional view showing a microbubble generating pump according to a fourth embodiment of the present invention.
FIG. 16 is a schematic diagram showing a specific example of a moving blade of a microbubble generating pump according to a fourth embodiment of the present invention.
FIG. 17 is a schematic diagram showing the results of an experiment conducted using the microbubble generating pump according to the fourth embodiment of the present invention.
FIG. 18 is a schematic diagram showing the results of an experiment conducted using the microbubble generating pump according to the fourth embodiment of the present invention.
FIG. 19 is a sectional view showing a microbubble generating pump according to a fifth embodiment of the present invention.
FIG. 20 is a schematic diagram showing the results of an experiment conducted using the microbubble generating pump according to the fifth embodiment of the present invention.
FIG. 21 is a schematic diagram showing the results of an experiment conducted using the microbubble generating pump according to the fifth embodiment of the present invention.
FIG. 22 is a sectional view showing a microbubble generating pump according to a sixth embodiment of the present invention.
FIG. 23 is a sectional view showing a microbubble generating pump according to a seventh embodiment of the present invention.
FIG. 24 is a sectional view showing a microbubble generating pump according to an eighth embodiment of the present invention.
FIG. 25 is a perspective view showing a suction plate of a microbubble generating pump according to an eighth embodiment of the present invention.
FIG. 26 is a plan view showing a design example of the vortex impeller of the microbubble generating pump according to the eighth embodiment of the present invention.
FIG. 27 is a plan view showing a design example of the vortex impeller of the microbubble generating pump according to the eighth embodiment of the present invention.
FIG. 28 is a plan view showing a design example of the vortex impeller of the microbubble generating pump according to the eighth embodiment of the present invention.
FIG. 29 is a side view of the vortex impeller shown in FIG.
FIG. 30 is a sectional view showing an example of a suction plate when air is supplied from the suction plate in the microbubble generating pump according to the eighth embodiment of the present invention.
FIG. 31 is a sectional view showing another example of the suction plate when air is supplied from the suction plate in the microbubble generating pump according to the eighth embodiment of the present invention.
FIG. 32 is an enlarged cross-sectional view showing a bent portion of a corner of the through hole of the suction plate shown in FIG.
FIG. 33 is a sectional view showing a microbubble generating pump according to a ninth embodiment of the present invention.
FIG. 34 is a plan view showing a specific example of a stationary blade of a microbubble generating pump according to an eleventh embodiment of the present invention.
FIG. 35 is a side view of the stationary blade shown in FIG. 34.
FIG. 36 is a sectional view showing a microbubble generating pump according to a twelfth embodiment of the present invention.

11 Casing 12 Suction port 13 Discharge port 14 Rotor blade 14a Rotating shaft 14b Main body 14c Blade 15 Stator blade 15a Main body 15b Blade 16 Vortex collapse nozzle 16a Constricted flow portion 16b Vortex collapse portion 18 Swirling flow 22 Micro bubble generating pump 23 Micro bubble 41 Pressure Blocking nozzle 61 Suction plate 61a Through hole 62 Swirl impeller 62a Disc 62b Blade

  Hereinafter, modes for carrying out the invention (hereinafter referred to as “embodiments”) will be described.
  FIG. 1 shows a microbubble generating pump according to a first embodiment of the present invention.
  As shown in FIG. 1, the microbubble generating pump includes a moving blade 14, a stationary blade 15, and a stationary blade 15 that are sequentially arranged coaxially from a suction port 12 toward a discharge port 13 inside a casing 11 formed of a cylindrical pipe. A vortex breakdown nozzle 16 is provided. The moving blade 14 has a shaft 14 a provided integrally with the moving blade 14. The shaft 14 a is directly connected to the rotating shaft of the motor 17, and the rotating blade 14 can be rotated around the central axis by rotating the shaft 14 a by the motor 17. For example, a submersible motor is used as the motor 17, but is not limited to this.
  When this microbubble generating pump is placed in a liquid such as water, the liquid sucked from the suction port 12 is supplied to the moving blade 14 rotating around the central axis to generate a swirling flow. That is, the liquid sucked from the suction port 12 is closed at the center by a later-described cylindrical main body 14b of the rotor blade 14, and therefore a groove between the blades 14c existing on the outer peripheral surface of the main body 14b of the rotor blade 14. The swirl flow is generated by the rotation of the moving blade 14 around the central axis. This swirling flow is supplied to the stationary blade 15, and a gas is introduced into the center of the swirling flow at the stationary blade 15 or the subsequent stage of the stationary blade 15, and the swirling flow with the gas introduced into the center is supplied to the vortex breakdown nozzle 16. In the vortex breakdown nozzle 16, microbubbles are generated by causing vortex breakdown using the Coanda effect and discharged from the discharge port 13 together with the liquid.
  Here, when the swirl flow into which the gas has been introduced enters the vortex breakdown nozzle 16, the swirl flow is contracted, and a vortex breakdown occurs by generating a positive pressure gradient from the discharge port 13 toward the center of the stationary blade 15. . Due to this vortex breakdown, large bubbles are finely crushed and microbubbles are generated.
  Details of the moving blade 14 and the stationary blade 15 will be described. 2 and 3 show α_F≧ φ_F(Φ_FShows the rotor blade 14 and the stator blade 15 in the case of the angle of the terminal portion 15d of the stator blade 15 with respect to the circumferential direction of the blade 15b. Figure 4 shows α_F<Φ_FThe moving blade 14 and the stationary blade 15 in the case of are shown.
  As shown in FIG. 2, FIG. 3 and FIG. 4, the rotor blade 14 is composed of a cylindrical main body 14b and a plurality of same-shaped pieces provided on the outer peripheral surface of the cylindrical main body 14b at the same angle from each other. Wing 14c. The plurality of blades 14c are arranged so as to cut vertically on the outer peripheral surface of the cylindrical main body 14b, and from one end of the cylindrical main body 14b on the liquid outlet side, that is, from the end 14d to the other end, that is, the start end. It is provided to bend as it goes to 14e. In this case, the angle with respect to the circumferential direction of the moving blade 14 at the edge on the start end portion 14e side of the plurality of blades 14c is selected so that the liquid flow supplied to the moving blade 14 does not separate from the plurality of blades 14c. Specifically, the angle with respect to the circumferential direction of the moving blade 14 at the edge on the start end portion 14e side of the plurality of blades 14c is θ._I, The angle of attack Δα = (θ with respect to the flow of the liquid supplied to the moving blade 14 as viewed from the rotating coordinate system rotating with the moving blade 14_I-Α_I) Is larger than 0 degree and 20 degrees or less, typically 5 degrees or more and 20 degrees or less (see FIG. 5). Where α_I= Tan^-1(U_I/ RΩ), U_IIs the flow velocity of the liquid sucked into the moving blade 14 when viewed from the stationary coordinate system, R is the radius of the moving blade 14, and Ω is the angular velocity of the moving blade 14. Further, an angle θ with respect to the circumferential direction of the moving blade 14 at the edge on the terminal end 14d side of the plurality of blades 14c._FIs selected, for example, from 85 degrees to 90 degrees.
  If the volume flow rate of the liquid passing through the microbubble generating pump is Q,
Is established. Where S_I, S_FAre the fluid cross-sectional areas at the start end 14e and the end end 14d of the rotor blade 14, respectively. Axial flow velocity U_I, U_FIs invariant even when viewed in a rotating coordinate system that rotates with the moving blade 14. Therefore, the rotational direction component of the flow velocity at the end portion 14d of the moving blade 14 when viewed from the rotating coordinate system rotating with the moving blade 14 is U_F/ Tanθ_FIt becomes. From the above, the ejection angle α of the fluid from the moving blade 14 when viewed from the stationary coordinate system_FIs
(However, it is assumed that the flow does not separate at the end portion 14d of the rotor blade 14).
  The stationary blade 15 includes a columnar body 15a and a plurality of blades 15b having the same shape and provided on the outer peripheral surface of the columnar body 15a at the same angle. The plurality of wings 15b are arranged so as to be longitudinally cut on the outer peripheral surface of the cylindrical main body 15a and to one end on the side to which the swirling flow of the cylindrical main body 15a is supplied, that is, from the start end 15c to the other end, That is, it is provided so as to bend toward the end portion 15d. In this case, an angle φ with respect to the circumferential direction of the stationary blade 15 at the edge of the plurality of blades 15b on the start end portion 15c side._IIs selected so that the swirl flow supplied from the moving blade 14 does not separate from the plurality of blades 15b. Specifically, α_F> Φ_IIs the angle of attack (α_F−φ_I) Is selected to be greater than 0 degree and 20 degrees or less, and φ_I> Α_FIn the case of the angle of attack (φ_I-Α_F) Is selected to be greater than 0 degrees and 20 degrees or less.
  The stationary blade 15 is designed as follows.
  First, the angle φ of the blade 15b at the end portion 15d of the stationary blade 15 with respect to the circumferential direction of the stationary blade 15 from the condition for causing vortex breakdown, that is, the condition where the swirling flow velocity is twice or more the flow velocity in the central axis direction_FBut
  cotφ_F≧ 2 (φ_F≦ 26 degrees)
Decide to meet. Next, φ_FAnd α_FThe size is compared with (the ejection angle of the fluid from the moving blade 14 as seen from the stationary coordinate system), and determined so as to satisfy the following condition, that is, the condition that the flow does not separate.
  φ_F≦ α_FWhen
  φ_F≦ φ_IAnd α_F-20 degrees <φ_I≦ α_F(0 degrees <α_F−φ_I≤ 20 degrees)
  φ_F> Α_FWhen
  φ_I≦ φ_FAnd α_F<Φ_I≦ α_F+20 degrees (0 degrees <φ_I-Α_F≤ 20 degrees)
  In this case, the plurality of blades 15 b are configured such that no gap appears when projected in the central axis direction of the stationary blade 15. Specifically, the plurality of blades 15 b are projected in the central axis direction of the stationary blade 15. Sometimes configured to overlap each other.
  Where α_FAnd φ_FIn order to generate vortex breakdown, the final flow velocity direction is φ_FIn addition, the design may be made so as to satisfy the vortex breakdown condition in the direction of the flow velocity. However, the final flow direction is φ_FIn order to achieve this, it is necessary to control the flow so as to be in the direction along the stationary blade 15. For this purpose, as described above, the plurality of blades 15b need to be configured to overlap each other when projected in the direction of the central axis of the stationary blade 15. As described above, the plurality of blades 15b are configured to overlap each other when projected in the central axis direction of the stationary blade 15, and thus the reverse flow (pump) generated because the inside of the casing 11 has a low pressure due to the generated swirling flow. It is also possible to effectively prevent the liquid sucked from the discharge port 13 from being discharged from the suction port 12 of the pump.
  6 and 7 are a longitudinal sectional view and a perspective view of the stationary blade 15, respectively. As shown in FIGS. 6 and 7, one of the plurality of blades 15b of the stationary blade 15 is provided with an air supply hole 15e. An injection hole 15f is provided on the central axis of the other end 15d of the cylindrical main body 15a. The air supply hole 15e and the injection hole 15f communicate with each other through a passage 15g provided in the cylindrical main body 15a. A hole (not shown) is provided in a portion of the casing 11 corresponding to the air supply hole 15e provided in one blade 15b, and a pipe for gas introduction (not shown) is connected to the hole from the outside.
  A specific example of the moving blade 14 is shown in FIG. The moving blade 14 has four blades 14c. FIG. 8 is a developed view in the circumferential direction of the outer peripheral surface of the cylindrical main body 14b of the moving blade 14, and shows the shape of the four blades 14c. The length (blade length) of the moving blade 14 in the central axis direction is 4.1 cm.
  FIG. 9A shows a specific example of the stationary blade 15, and FIG. 9B shows a state where the stationary blade 15 is inside the casing 11. The stationary blade 15 has four blades 15b. In FIG. 9A, the arrows indicate the direction of flow. As shown in FIGS. 9A and 9B, in this stationary blade 15, in order to prevent backflow, the four blades 15b are interposed between them when projected in the direction of the central axis of the stationary blade 15. It is comprised so that a clearance gap may not arise. In addition, the angle formed by the circumferential edge of the edge on the side where the swirling flow of the blade 15b of the stationary blade 15 exits is approximately 0 degrees.
  Details of the vortex breakdown nozzle 16 are shown in FIG.
  As shown in FIG. 10, the vortex breakdown nozzle 16 includes a contracted flow portion 16a and a vortex collapse portion 16b that are formed in a tapered shape. The contracted flow portion 16a is a tube that is tapered, and the narrow side is connected to the vortex collapse portion 16b. The narrowing angle (taper angle) 16e of the contracted flow portion 16a depends on the size of the casing 11 and is selected as necessary. An example of the angle 16e is about 20 degrees, but is not limited thereto. A tapered portion 16h is provided at the tip of the vortex breaking portion 16b, and the outlet extends in a tapered shape. The exit angle (taper angle) 16i of the vortex breakdown part 16b is, for example, about 60 degrees or 80 degrees, but is not limited thereto.
  In this vortex breakdown nozzle 16, the air column formed at the center of the swirl flow 18 passes through the vortex breakdown portion 16b and sticks as bubbles in the tapered portion 16h by the Coanda effect. The bubbles stuck to the taper portion 16h are sheared or crushed by the swirling flow 18, and microbubbles are generated. As the air column sticks to the tapered portion 16h in this way, the time during which the bubbles are subjected to shearing becomes longer, and the atomization of the bubbles is promoted.
  Note that due to the Coanda effect, the swirling flow 18 enters the tapered portion 16h from the vortex breaking portion 16b and spreads in a tapered shape, so that the air column also spreads, and the bubbles stick to the tapered portion 16h.
  The size of the vortex breakdown nozzle 16 is about the same as the inner diameter 16f for the length 16g of the cylindrical vortex breakdown portion 16b.
  Next, application examples of the microbubble generation pump will be described. Below, the example which applied this microbubble generation pump to the water purification of pond water is demonstrated. An example of this is shown in FIG.
  As shown in FIG. 11, in this example, the microbubble generating pump 22 is installed near the bottom 21 a of the pond 21, the microbubbles 23 are generated from the microbubble generating pump 22, and supplied to the water of the pond 21. To do. For example, a submersible motor is used as the motor 17 of the microbubble generating pump 22. The electric power of the motor 17 is supplied via a cable 25 from a solar cell panel 24 that receives sunlight and generates electric power. Since the energy efficiency of the microbubble generating pump 22 is high and therefore the power consumption of the motor 17 is also low, the power supplied by the solar cell panel 24 is sufficient to drive the motor 17. For example, the power generation capacity of the solar cell panel 24 may be about 0.3 kW.
  According to the first embodiment, the microbubble generating pump includes a moving blade 14, a stationary blade 15, and a vortex breaking nozzle 16 that are sequentially arranged coaxially from the suction port 12 toward the discharge port 13 inside the casing 11. The microbubbles are generated by sucking the liquid from the suction port 12 and causing the vortex breakup nozzle 16 to cause vortex collapse, and the microbubbles are discharged from the discharge port 13 together with the liquid. Can be generated. Moreover, this microbubble generating pump is suitable for low flow and large flow rate applications. For this reason, this microbubble generating pump is suitable for application over a wide range of time for the purpose of purifying water areas.
  Next explained is a microbubble generating pump according to the second embodiment of the invention.
  As shown in FIG. 12, this micro-bubble generating pump is sequentially arranged coaxially from the suction port 12 to the discharge port 13 inside the casing 11 formed of a cylindrical pipe, as in the first embodiment. The rotor blades 14, the stationary blades 15, and the vortex breakdown nozzle 16. In addition to these, the microbubble generating pump includes a moving blade 31 and a stationary blade 32 that are sequentially arranged coaxially from the suction port 12 toward the discharge port 13 on the suction port 12 side of the moving blade 14. The moving blade 31 is provided integrally with the shaft 14 a of the moving blade 14, and the shaft 14 a can be rotated around the central axis together with the moving blade 14 by rotating the shaft 14 a by the motor 17.
  In this case, the moving blade 31 includes a cylindrical main body 31a and a plurality of blades 31b provided on the outer peripheral surface of the cylindrical main body 31a. The plurality of blades 31b are arranged so as to cut vertically on the outer peripheral surface of the columnar main body 31a and from one end of the columnar main body 31a on the liquid outlet side, that is, from the terminal end 31c to the other end, that is, the start end. It is provided so as to bend toward 31d. The plurality of blades 31b have the same shape on the outer peripheral surface of the cylindrical main body 31a and are provided at equal intervals. The stationary blade 32 includes a columnar main body 32a and a plurality of blades 32b provided on the outer peripheral surface of the columnar main body 32a. The plurality of blades 32 b are provided so as to cut vertically on the outer peripheral surface of the cylindrical main body 32 a in the direction of the central axis of the stationary blade 32. That is, the plurality of blades 32 b are provided in a direction parallel to the central axis of the stationary blade 32. Similarly to the first embodiment, the moving blade 14 includes a cylindrical main body 14b and a plurality of blades 14c provided on the outer peripheral surface of the cylindrical main body 14b. Are provided so as to be longitudinally cut on the outer peripheral surface of the columnar main body 14b and to bend from the end portion 14d to the start end portion 14e of the columnar main body 14b. Similarly to the first embodiment, the stationary blade 15 includes a cylindrical main body 15a and a plurality of blades 15b provided on the outer peripheral surface of the cylindrical main body 15a. Are provided so as to be longitudinally cut on the outer peripheral surface of the columnar main body 15a and to bend from the start end portion 15c to the end portion 15d of the columnar main body 15a.
  According to the second embodiment, in addition to the same advantages as those of the first embodiment, a high-lift microbubble generating pump can be realized as compared with the microbubble generating pump according to the first embodiment. The advantage of being able to
  Next explained is a microbubble generating pump according to the third embodiment of the invention.
  In this microbubble generating pump, the moving blade 14 in the microbubble generating pump according to the first embodiment has the same shape as the moving blade of the mixed flow pump that generates the head by the centrifugal force of the liquid. An example of the shape of the moving blade 14 is shown in FIGS. 13, 14A and 14B. The shape of the edge on the suction port 12 side of the plurality of blades 14c of the moving blade 14 is selected to be a shape capable of obtaining a high head, and the shape on the discharge port 13 side is a shape capable of obtaining the swirling flow 18. Has been chosen. Specifically, in this case, the moving blade 14 is formed on, for example, a truncated cone-shaped main body 14b whose cross-sectional area increases in the direction from the suction port 12 to the discharge port 13 of the microbubble generating pump, and the outer peripheral surface of the main body 14b. The blades 14c are provided so as to be longitudinally cut on the outer peripheral surface of the main body 14b and to bend from the terminal portion to the starting end portion of the main body 14b. As described above, the shape on the discharge port 13 side of the plurality of blades 14c of the moving blade 14 is selected to be a shape capable of obtaining the swirling flow 18, which is largely different from the mixed flow pump. For reference, the shape of the blade 14c in the mixed flow pump is shown by a one-dot chain line in FIG. 14B.
  Other configurations of the microbubble generating pump are the same as those of the microbubble generating pump according to the first embodiment.
  According to the third embodiment, in addition to the same advantages as those of the first embodiment, it is possible to obtain the advantage that a higher-lift microbubble generating pump can be obtained.
  Next explained is a microbubble generating pump according to the fourth embodiment of the invention.
  As shown in FIG. 15, in this microbubble generating pump, a pressure blocking nozzle 41 is provided at the tip (downstream side) of the vortex breaking nozzle 16 in the microbubble generating pump according to the first embodiment. . More specifically, a pressure blocking nozzle 41 is installed on the downstream end face P1 side of the vortex breakdown nozzle 16b, coaxially with the vortex breakdown nozzle 16 and facing the vortex breakdown nozzle 16b. Yes. The outer shape of the pressure blocking nozzle 41 has a cylindrical shape like the vortex breaking nozzle 16 and has the same diameter as the outer diameter of the casing 11, for example, but is not limited thereto. The vortex breaking portion 16b has a cylindrical bubble outlet T. A gap 42 is formed between the end face P1 on the downstream side of the vortex breaking portion 16b and the end face P2 on the upstream side of the pressure blocking nozzle 41. The gap 42 gradually increases linearly from the central axis of the vortex breaking nozzle 16 and the pressure blocking nozzle 41 in the radial direction. The portion of the pressure blocking nozzle 41 facing the jet outlet T is configured to block the low pressure portion at the center of the swirling flow coming out of the jet outlet T from the downstream side of the pressure blocking nozzle 41. ing. In other words, in this case, a through hole is not provided in a portion of the pressure blocking nozzle 41 that faces the ejection port T. Further, the portion of the pressure blocking nozzle 41 that faces the jet outlet T does not penetrate the vortex collapse portion 16b, more specifically, the jet outlet T. In this case, a gas-liquid mixed phase flow (for example, a mixed phase flow of water and air) is ejected from the outlet T of the vortex breaking portion 16b, and microbubbles are generated at the edge 16k and the tapered portion 16h. Microbubbles are released into (liquid such as water).
  By providing the pressure blocking nozzle 41 at the tip of the vortex breaking nozzle 16, the following effects can be obtained.
(A) Noise accompanying generation of sound waves can be reduced.
  The generation of sound waves causes noise problems when the microbubble generation pump is used for consumer goods or water quality improvement, and the sound waves emitted from the microbubble generation pump are the swirl frequency and the natural frequency of the air column formed inside the pump. There are two types of vibrations. In this case, since the pressure blocking nozzle 41 is installed on the downstream side of the vortex breakdown nozzle 16, the vortex breakdown can be changed from the spiral type to the bubble type. The bubble-type vortex collapse has a small external force to expand and contract the air column, so the air column sound is reduced. Moreover, since the pressure blocking nozzle 41 is fixed to the end face P1 side on the downstream side of the vortex breakdown nozzle 16, the turbulence of the swirling flow 18 is reduced, and swirling noise and air column noise are reduced.
(B) It is possible to prevent re-suction of the released fluid when released in water.
  It is possible to prevent the floc from being broken and dispersed in the liquid by re-inhaling the released fluid when the floc is floated and separated by microbubbles. That is, the microbubble water discharged by the pressure blocking nozzle 41 is not re-sucked.
(C) Re-foaming of the dissolved gas due to the generation of the low-pressure part at the center of the swirling flow can be prevented.
  In the microbubble generating pump, the pressure at the center of the swirling flow decreases, and this decrease in gas pressure means that dissolved gas precipitates as a gas simultaneously with the reduction of the generated bubble diameter. In this case, the pressure at the jet outlet T of the vortex collapsing portion 16b can be increased by providing the contracted flow portion by installing the pressure blocking nozzle 41.
  The results of experiments using this microbubble generating pump will be described.
  In this experiment, the inner diameter of the casing 11 is 79 mm, the inner diameter 16f of the vortex breaking portion 16b of the vortex breaking nozzle 16 is 30 mm, and the pressure blocking nozzle 41 is used (between the vortex breaking nozzle 16 and the pressure blocking nozzle 41). The minimum flow distance h = 3.0 mm) and when not used were measured for flow rate and suction pressure. As shown in FIG. 16, the outer diameter of the rotor blade 14 is 78 mm, the length (blade length) of the cylindrical main body 14 b is 41.8 mm or 23.0 mm, the diameter of the main body 14 b is 38 mm, and the height of the blade 14 c is high. The length is 20 mm, and the number of blades 14c is four. However, if the cross-sectional area of the groove between the blades 14c of the rotor blade 14 is small, a sufficient flow rate cannot be obtained. Therefore, after the blade 14c is once formed as shown in FIG. 16, it is indicated by a dotted line in FIG. As described above, the experiment was performed by cutting the front edge portion of the blade 14c and sufficiently increasing the cross-sectional area of the groove between the blades 14c. The outer diameter of the stationary blade 15 is 79 mm, the length (blade length) of the cylindrical main body 15a is 10 mm, the diameter of the main body 15a is 38 mm, the height of the blade 15c is 20 mm, and the number of the blades 15c is four. Further, a submersible motor was used as the motor 17.
  17 and 18 show the experimental results. 17 and 18 are plots of the flow rate (L / min) and the suction pressure (kPa) against the power consumption of the submersible motor. As shown in FIGS. 17 and 18, both the flow rate and the suction pressure are greatly affected by the pressure blocking nozzle 41. By selecting the minimum distance h between the vortex breaking nozzle 16 and the pressure blocking nozzle 41 to be the optimum value of 3.0 mm, the flow rate is increased by more than 50% compared to when the pressure blocking nozzle 41 is not provided. .
  In addition, by reducing the blade length of the moving blade 14, the flow rate and suction pressure at the same power consumption are increased. This indicates that the energy efficiency of the microbubble generating pump can be further improved by optimally selecting the shape of the blade 14c.
  Although illustration is omitted, in the experiment in which the blade length of the moving blade 14 is 20.0 mm, the flow rate becomes 100 L / min by optimally arranging the pressure blocking nozzle 41. On the other hand, when the pressure blocking nozzle 41 was not used, the power consumption was 0.75 kW and the flow rate was 60 L / min.
  Since the generation efficiency of microbubbles is proportional to the flow rate, it was shown that this microbubble generation pump has a microbubble generation mechanism with low power consumption.
  On the other hand, the air suction pressure tends to be somewhat reduced by installing the pressure blocking nozzle 41, but can be controlled by optimally selecting the moving blade 14 and the stationary blade 15.
  According to the fourth embodiment, the same advantages as in the first embodiment can be obtained.
  Next explained is a microbubble generating pump according to the fifth embodiment of the invention.
  In the microbubble generating pump according to the first embodiment, the vortex breaking nozzle 16 is accommodated and fixed inside the casing 11, whereas in the microbubble generating pump, as shown in FIG. The casing 11 corresponding to the vortex breakdown nozzle 16 is processed into the same shape as the inner peripheral surface of the contracted flow portion 16 a and the vortex breakdown portion 16 b of the vortex breakdown nozzle 16, and this portion becomes the vortex breakdown nozzle 16. ing. In FIG. 19, the motor 17 for driving the rotor blade 14 is not shown. Others are the same as those of the microbubble generating pump according to the first embodiment.
  The results of experiments using this microbubble generating pump will be described.
  In this experiment, the dimensions of each part of the microbubble generating pump are set as shown in FIG. 19 and a pressure blocking nozzle 41 (not shown in FIG. 19) is used (vortex breaking nozzle 16 and pressure blocking). The power consumption, the flow rate, and the suction pressure were measured for the case where the minimum distance h to the nozzle 41 for use h = 5.0 mm) was not used and the inner diameter 16f of the vortex breaking nozzle 16 was 4 cm or 3 cm. A flange portion 11 a is provided on the suction port 12 side of the casing 11, and the suction port 12 side is covered with a bottom plate 51. The bottom plate 51 was fixed to the flange portion 11a with screws 52. The moving blade 14 is rotated by a motor 17, but only the rotating shaft 17a of the motor 17 directly connected to the shaft 14a of the moving blade 14 is shown in FIG. A submersible motor was used as the motor 17. This submersible motor can be loaded up to 0.55 kW with a rating of 0.3 kW. In the center of the bottom plate 51, a through hole 51a having a diameter larger than the diameter of the rotating shaft 17a is provided. And water is sucked from the gap between the through hole 51a and the rotating shaft 17a.
  20 and 21 show the experimental results. 20 and 21 plot the flow rate (L / min) and the suction pressure (kPa) against the power consumption of the submersible motor. As shown in FIGS. 20 and 21, when the inner diameter 16f of the vortex breakdown nozzle 16 is increased, the flow rate is increased, but the suction pressure is decreased. Further, when the pressure blocking nozzle 41 is provided, both the flow rate and the suction pressure increase, and the efficiency increases.
  According to the fifth embodiment, the same advantages as those of the first embodiment can be obtained.
  Next explained is a microbubble generating pump according to the sixth embodiment of the invention.
  In this microbubble generating pump, both the angles of both ends of the blade 14c are in the circumferential direction of the cylindrical main body 14b so that the rotor blade 14 can generate a swirling flow not only downstream but also upstream. For example, the angle is about 90 to 85 degrees. As shown in FIG. 22, in this microbubble generating pump, as in the microbubble generating pump according to the fifth embodiment, the portion of the casing 11 corresponding to the vortex breaking nozzle 16 is compressed. It is processed into the same shape as the inner peripheral surface of the flow part 16a and the vortex breaking part 16b. In addition to this, the casing 11 in the portion between the suction port 12 and the moving blade 14 has a cross-sectional area that decreases from the suction port 12 toward the moving blade 14, and reaches the minimum cross-sectional area. It is processed to increase again toward. Gas (air or the like) is supplied from the outside to the inside of the casing 11, preferably the portion having the smallest cross-sectional area, between the inlet 12 and the rotor blade 14. Then, vortex breakdown occurs inside the casing 11 at the portion having the minimum cross-sectional area. At this time, the condition for causing vortex breakdown is that the flow becomes supercritical in the section of the cross section where the cross sectional area is minimized. Specifically, when the pump flow rate is Q, the radius of the cross section where the cross sectional area is minimum is r, and the rotational angular velocity of the moving blade 14 is ω, the following conditions are satisfied.
  When calculating
It becomes. Where S_{e, cr}Is about 2 in terms of critical circulation.
  In this case, the liquid sucked from the suction port 12 is contracted and a swirl flow is generated because the cross-sectional area of the casing 11 decreases from the suction port 12 toward the moving blade 14. At this time, the angle of attack Δα on the upstream side (suction port 12 side) of the blade 14c of the rotor blade 14 is set to be large so that a swirl flow is easily generated, specifically, for example, 20 degrees <Δα <90 degrees. Is selected within the range. This swirling flow becomes unstable (instability of the vortex core) and enters into a portion where the cross-sectional area increases from the minimum cross-sectional area portion of the casing 11, and vortex collapse occurs. At this time, the flow changes from supercritical to subcritical, and strong turbulence is generated.
  As can be seen from the above, in this microbubble generation pump, in addition to the vortex breakdown nozzle 16 that causes the vortex breakdown using the Coanda effect, the instability of the vortex core is provided in the preceding stage (on the suction port 12 side). Therefore, it can be considered that another vortex breakdown nozzle for causing vortex breakdown is provided.
  According to the sixth embodiment, the same advantages as those of the first embodiment can be obtained, and the following advantages can be obtained. That is, this microbubble generating pump can be used in water, for example, and can produce a large amount of air having a volume flow rate of several percent of the volume flow rate of water and release it in water in a large amount unless microbubble generation is involved. For this reason, compared with a general microbubble generator, the dissolved oxygen supply efficiency can be greatly improved.
  Next explained is a microbubble generating pump according to the seventh embodiment of the invention.
  In the microbubble generating pump according to the first embodiment, a submersible motor is used as the motor 17, but it is not always necessary to use a submersible motor. Therefore, in this microbubble generating pump, a case where a normal motor other than the submersible motor is used as the motor 17 will be described.
  That is, as shown in FIG. 23, a hole is made in the casing 11, and the rotating shaft 14a of the rotor blade 14 is passed through this hole. Then, a mechanical seal is applied to the motor 17. In this way, even if the microbubble generating pump is put in water, the motor 17 can be prevented from being submerged or leaked.
  Next explained is a microbubble generating pump according to the eighth embodiment of the invention.
  As shown in FIG. 24, in this micro-bubble generating pump, the suction plate 61 and the vortex impeller 62 are provided with a stationary blade instead of the moving blade 14 of the micro-bubble generating pump according to the first embodiment. 15 and the vortex breaking nozzle 16 are sequentially provided from the suction port 12 toward the stationary blade 15. The suction plate 61 is fixed to the casing 11. On the other hand, the vortex impeller 62 is provided with a shaft 63 directly connected to the tip of the rotating shaft 17 a of the motor 17, and the vortex impeller 62 can be rotated by rotating the shaft 63 by the motor 17. It can be done.
  A perspective view of the suction plate 61 is shown in FIG. As shown in FIG. 25, a through hole 61a is provided in the center of the suction plate 61. The cross-sectional shape of the through hole 61a in the direction perpendicular to the central axis of the suction plate 61 is circular. The suction plate 61 is fitted into the suction port 12 of the casing 11 and closes the suction port 12 except for the through hole 61a. The liquid is sucked into the inside through the through hole 61 a of the suction plate 61.
  The vortex impeller 62 includes a disk 62a and a plurality of blades 62b provided on one surface of the disk 62a perpendicular to the surface. These blades 62b are rotationally symmetric about the central axis of the vortex impeller 62 and have a radius D from the central axis of the disk 62a._miExtending from the circumference of the disc to the outer circumference of the disc 62a. The shape of the blades 62b is not particularly limited as long as a swirl flow can be generated by the liquid entering the swirl impeller 62. For example, as shown in FIG. It is preferable to provide it so that it may extend linearly in the radial direction. The shape of these blades 62b may be provided so as to curve from the inside to the outside as shown in FIG. The number of the blades 62b is selected as necessary, but is 3 to 6, for example.
  The shape of the blade 62b of the vortex impeller 62 will be described more generally. FIG. 28 shows a plan view of the vortex impeller 62. As shown in FIG. FIG. 29 shows a side view of the vortex impeller 62. FIG. 28 shows a case where the number of blades 62b is five as an example, but the present invention is not limited to this. The angle formed by the radial direction of the disc 62a and the tangent of the blade 62b is θ_Fdeg(Angle expressed in degrees). The shape of the blade 62b is θ_Fdeg= Represented by a curve represented by a certain formula. Specifically, considering the (x, y) coordinate system and polar coordinate system (r, θ) shown in FIG.
  x = r (θ) cos θ, y = r (θ) sin θ
  r (θ) = R_inexp (θcotθ_F)
  θ_F= Π (θ_Fdeg/ 180)
It is expressed. Where R_in= D_mi/ 2, R_I= D_mo/ 2 (see FIG. 29). θ_FdegWhen = 0, the shape of the blade 62b is linear (see FIG. 26). θ_FdegAs the value increases, the swirl flow decreases and the radial flow increases. In the example shown in FIG._Fdeg= 40 degrees, R_in= 4mm, R_I= 15 mm.
  In this microbubble generating pump, as shown by an arrow in FIG. 24, the liquid sucked from the suction port 12 passes through the through hole 61a of the suction plate 61 and passes through the groove between the blades 62b of the vortex impeller 62. The vortex breaking nozzle 16 is entered from the outside of the vortex impeller 62 through the groove between the blades 15 b of the stationary blade 15.
  The diameter of the vortex impeller 62 is D_m0When the diameter of the main body 15a of the stationary blade 15 is D, the swirl flow generated by the vortex impeller 62 and the flow in the central axis direction of the microbubble generating pump can pass through the stationary blade 15. , D_m0≧ D is selected. Further, the portion (diameter D) where the vortex impeller 62 does not have the vane 62b._mi), A jet passing through the through hole 61a of the suction plate 61 is formed. In this case, the diameter of the through hole 61a of the suction plate 61 is D_sThen, in order to increase the suction pressure, in general, D_mi~ D_sAnd Further, when the shaft 63 directly connected to the rotating shaft 17a of the motor 17 is inserted into the through hole 61a of the suction plate 61, the diameter of the shaft 63 is set to D to ensure a fluid cross-sectional area._pD_s> D_p, But the diameter D of the shaft 63_pIs D_sShould be as small as possible, for example D_s≧ 2D_pIs preferable.
  Air supply to the liquid sucked from the suction port 12 may be performed in the stationary blade 15 or the subsequent stage, but may be performed from the suction plate 61. FIG. 30 is a sectional view including the central axis of the suction plate 61. As shown in FIG. 30, an air supply hole 61c is provided on the inner surface of the through hole 61a. The air supply hole 61 c reaches the outer peripheral surface of the suction plate 61 through a passage 61 d provided in the suction plate 61. A hole (not shown) is provided in a portion of the casing 11 corresponding to the passage 61d, and a gas introduction pipe (not shown) is connected to the hole from the outside.
  In this case, the shape of the through hole 61a of the suction plate 61 is preferably selected as follows. For example, as shown in FIG. 31, the through hole 61a has a tapered shape in which the diameter of the through hole 61a gradually increases in the liquid flow direction. The taper angle θ is, for example, about 2 to 5 degrees, but is not limited to this. The corner of the through hole 61a has a large curvature so that the flow is separated. By doing so, as shown in FIG. 32, an air film 64 is generated on the inner surface of the through hole 61a, so that gas is evenly supplied in the circumferential direction of the vortex impeller 62.
  As described above, the advantage of supplying air from the suction plate 61 is that the bubbles are crushed by the vortex impeller 62 and are pressurized and dissolved by the lift of the vortex impeller 62, so that the generation efficiency of fine bubbles is improved. Be able to.
  Specifically, the stationary blade 15 can be designed as follows. The radius of the stationary blade 15 is R_DFor simplicity, D = D_m0≡2R_IAnd At this time, the ejection angle α of the fluid from the vortex impeller 62 viewed from the stationary coordinate system_FIs approximately
Can be estimated from Where U_D, U_FAre the axial flow velocities at the beginning and end of the vortex impeller 62, θ_FIs the angle of the blade 62 b at the end of the vortex impeller 62 with respect to the circumferential direction of the vortex impeller 62, h is the height of the blade 62 b, and Ω is the angular velocity of the vortex impeller 62. Α obtained from equation (3)_F0 degrees <α_F−φ_I≦ Starting angle φ of stator blade 15 by substituting into the equation of 20 degrees_ICan be estimated.
  In order for the pressure to sufficiently decrease at the suction port of the suction plate 61, that is, the through hole 61 a, it is necessary that the radial flow of the vortex impeller 62 is not extremely restricted by the inner wall of the casing 11. To that end, R_D≫R_IIs desirable.
  As a typical example of the vortex impeller 62, R_D≫R_IAnd θ_F= 90 degrees
It is. Furthermore, generally Q / (πR_I ³Ω) <1, so R_D≫R_IFrom equation (5)
It becomes. R_D≫R_IAbout R_D≧ 2R_IIs considered necessary.
  Inner radius R of casing 11_DAnd radius R of the vortex impeller 62_IThe relationship with is as follows.
  Due to the rotation of the vortex impeller 62, a pressure gradient is generated outward from the rotation shaft, and the pressure increases near the inner wall of the casing 11. This pressure acts as a force for flowing fluid through the stationary blade 15. The pressure on the inner wall of the casing 11 is equal to the inner radius R of the casing 11._DThe larger the value, the larger. Therefore, in order to flow a larger flow rate, R_D≫R_IIs desirable.
  Here, with respect to the vortex impeller 62, the distance in the radial direction from the central axis of the vortex impeller 62 is r, and the pressure by the vortex impeller 62 is roughly estimated to be R_DAnd R_IConsider the relationship.
  First, the flow in the casing 11 is divided into three regions, and the radial flow velocity V_r, Circumferential flow velocity V_φAsk for. That is,
Region I: a region without the blades 62b of the vortex impeller 62 (r <R_in)
Region II: Region where the blade 62b of the vortex impeller 62 is present (R_in<R <R_I)
Region III: Region outside the vortex impeller 62 (r> R_I)
Here, Q is a flow rate supplied from the through hole 61a of the suction plate 61, that is, the suction port.
  The pressure P caused by this flow ignores the viscosity, and Euler's equation of motion
Calculate from Here, ρ is the density of the fluid. Finally
It becomes. However, P₀Is the pressure at r = 0. When r → ∞ from equation (13), the pressure is
Asymptotically. This is the maximum pressure corresponding to a sufficiently large casing 11. Therefore, the inner diameter R of the casing 11_DThe pressure in equation (13) is P_infChoose to be close enough. Therefore, dimensionless quantity
And r when this is sufficiently smaller than 1 is obtained. For the sake of simplicity, dimensionless quantities ε, M, and n defined by the following equations are introduced.
Substituting equation (16) into equation (15)
It becomes. In the vortex pump blade, M is about 2 and ε << 1, so equation (17) is
It becomes. If Λ = 0.1, then n = 2.2. At this time, it can be considered that the influence of the flow in the radial direction being restricted by the casing 11 is sufficiently small. On the other hand, when n = 1.5, Λ = 0.22, and when n = 1, Λ = 0.5, and half of the pressure due to the swirling flow is not utilized due to the influence of the casing 11.
  According to the eighth embodiment, advantages similar to those of the first embodiment can be obtained, and microbubbles can be efficiently generated using the small motor 17 with low power consumption.
  Next explained is a microbubble generating pump according to the ninth embodiment of the invention.
  As shown in FIG. 33, when it is desired to reduce the swirl direction flow velocity of the flow generated by the vortex impeller 62 and increase the axial flow velocity, the vane 15b of the stationary blade 15 is formed in a straight line as a simple shape. To do. The rest of the microbubble generating pump is the same as that of the microbubble generating pump according to the eighth embodiment.
  According to the ninth embodiment, the same advantages as in the eighth embodiment can be obtained.
  Next explained is a microbubble generating pump according to the tenth embodiment of the invention.
  In this microbubble generating pump, a motor 17 is incorporated in the main body 15 a of the stationary blade 15, and the vortex impeller 62 can be rotated by the motor 17. Other configurations of the microbubble generating pump are the same as those of the microbubble generating pump according to the eighth embodiment.
  According to the tenth embodiment, in addition to the same advantages as in the eighth embodiment, the rotating shaft 17a of the motor 17 does not penetrate the through hole 61a of the suction plate 61. An advantage can be obtained in that the liquid can be flowed throughout, and the flow rate that can be passed through the microbubble generating pump can be increased.
  Next explained is a microbubble generating pump according to the eleventh embodiment of the invention.
  In this microbubble generating pump, unlike the microbubble generating pump according to the eighth embodiment, when the blade 15b of the stationary blade 15 is projected in the direction of the central axis of the stationary blade 15, these blades 15b overlap each other. Not. That is, since the flow generated by the vortex impeller 62 does not generate a backflow, it is not necessary to overlap the blade 15b of the stationary blade 15. As a result, the gap between the blades 15b becomes large, and suspended matters (fibers, solids, etc.) in the liquid can be easily passed through the gap. Specifically, for example, as shown in FIG. 34, when the blade 15b of the stationary blade 15 is projected in the direction of the central axis of the stationary blade 15, there is a gap between the blade 15b and the blade 15b. In the vortex impeller 62, φ_F> Α_FTherefore, the shape of the blade 15b of the stationary blade 15 can be the same as that of the first embodiment. Φ_FIs φ_FSince it is necessary to satisfy ≦ 26 degrees, there is almost no possibility of separation at the starting end of the blade 62b of the vortex impeller 62 (in order to satisfy the vortex breakdown condition even if the vortex breakdown nozzle 16 contracts, φ_F≦ 20 degrees), the blade 62b is straight (φ_F= Φ_I). A side view of the stationary blade 15 is shown in FIG. As shown in FIGS. 34 and 35, each of the plurality of blades 15b of the stationary blade 15 is provided with an air supply hole 15e. An injection hole 15f is provided on the central axis of the start end 15d of the main body 15a. The air supply hole 15e and the injection hole 15f communicate with each other via a passage 15g provided in the main body 15a and the blade 15b. A hole (not shown) is provided in a portion of the casing 11 corresponding to each air supply hole 15e, and a gas introduction pipe (not shown) is connected to the hole from the outside. As shown in FIG. 35, by increasing the inclination angle Θ of the blade 15b of the stationary blade 15, the flow rate of the microbubble generating pump can be increased. However, when Θ is 20 degrees or more, separation occurs, and the flow rate becomes smaller.
  According to the eleventh embodiment, the same advantages as in the eighth embodiment can be obtained, and when the blade 15b of the stationary blade 15 is projected in the direction of the central axis of the stationary blade 15, the blade 15b. Since there is a gap between the blade 15b and the blade 15b, the flow rate through the stationary blade 15 can be increased, and the generation efficiency of microbubbles can be sufficiently increased.
  Next explained is a microbubble generating pump according to the twelfth embodiment of the invention.
  As shown in FIG. 36, in this microbubble generating pump, unlike the microbubble generating pump according to the eighth embodiment, the stationary blade 15 is not provided.
  Conditions for generating vortex breakdown by the vortex breakdown nozzle 16 without providing the stationary blade 15 in this way are shown below.
  The radius of the inner surface of the vortex breakdown portion 16b of the vortex breakdown nozzle 16 is defined as r._eIf it is set as (1/2 of the inner diameter 16f of the vortex collapse part 16b), the average flow velocity in the axial direction in the vortex collapse part 16b is
Given in. On the other hand, the swirling flow velocity in the vortex breaking portion 16b of the vortex breaking nozzle 16 can be calculated assuming that the swirling flow generated by the vortex impeller 62 follows the law of circulation. Circulation C generated by the vortex impeller 62 is
In the vortex breakdown portion 16b of the vortex breakdown nozzle 16, the circumferential flow velocity is V_eAfter all,
It becomes. From equations (20) and (21)
Is obtained. U_FIs based on continuous flow conditions
It becomes.
  Now, the circulation number Γ of the vortex breakdown portion 16b of the vortex breakdown nozzle 16_eIs
It becomes. Since the flow rate Q generated in the vortex impeller 62 is proportional to the area and rotational speed of the blade 62b,
And can be put. Here, ζ is the radius r of the inner surface of the vortex breakdown portion 16b of the vortex breakdown nozzle 16._eThe radius R of the through hole 61a of the suction plate 61_s(= D_s/ 2) and θ_FIt is a dimensionless coefficient that depends on. Substituting equation (25) into equation (24)
It becomes. Γ for vortex breakdown to occur_eSince it needs to be ≧ 2,
If the vortex impeller 62 and the vortex breakdown nozzle 16 are designed so as to be, even if there is no stationary blade 15, vortex breakdown can be generated and microbubbles can be generated. From dimensional analysis, ζ is R_s/ R_eAnd θ_FTherefore, if the relationship between parameters is specified in equation (27),
It becomes.
  From formula (28), a smaller h is advantageous for vortex breakdown. This is because the swirl flow is stronger than the flow rate. R_s≪r_eIn this case, that is, when the vortex breaking nozzle 16 is not provided, the flow rate becomes maximum.
It becomes. The maximum value in the equation (29) is considered to be on the order of 0.1 because O (ζ) = 0.1 in a general eddy current pump.
  In addition, θ_F= 90 degrees, equation (28) becomes
It becomes.
  Experiments have shown that the condition of formula (27) or formula (28) is necessarily satisfied. Conversely, to increase the generation efficiency of microbubbles, it is necessary to increase the flow rate by increasing the axial flow rate. For that purpose, θ of the rotor blade 14_FIt is advantageous to set the angle to about 40 degrees.
  According to the twelfth embodiment, in addition to the same advantages as those of the eighth embodiment, by not providing the stationary blade 15, the suspended matter (fiber or solid in the liquid passing through the microbubble generating pump). And the like can be enlarged, and the configuration of the microbubble generating pump can be simplified.
  Although the embodiment of the present invention has been specifically described above, the present invention is not limited to the above-described embodiment, and various modifications based on the technical idea of the present invention are possible.
  For example, the numerical values, shapes, structures, arrangements, and the like given in the above-described embodiments are merely examples, and different numerical values, shapes, structures, arrangements, and the like may be used as necessary.

Claims (19)

Inside the casing, it has a moving blade, a stationary blade and a vortex breakdown nozzle arranged sequentially coaxially from the suction port toward the discharge port,
Supplying the liquid sucked from the suction port to the moving blade to generate a swirling flow;
The moving blade is composed of a cylindrical main body and a plurality of wings provided on the outer peripheral surface of the cylindrical main body, and the plurality of wings run vertically on the outer peripheral surface of the cylindrical main body. And it is provided so as to bend as it goes from the one end portion on the liquid outlet side of the cylindrical main body to the other end portion,
The swirling flow is supplied to the stationary blade, a gas is introduced into the center of the swirling flow at the stationary blade or the latter stage of the stationary blade, and the swirling flow into which the gas has been introduced is supplied to the vortex breaking nozzle to be swirled. A microbubble generation pump that generates microbubbles by causing collapse and discharges the bubbles together with the liquid from the discharge port. The angle with respect to the circumferential direction of the moving blade at the edge on the other end side of the plurality of blades is selected so that the flow of the liquid supplied to the moving blade does not separate from the plurality of blades. The microbubble generating pump according to 1. The angle with respect to the circumferential direction of the moving blade at the edge on the other end side of the plurality of blades is θ _I , The absolute value of the angle of attack for the liquid flow supplied to the blade as seen from the rotating coordinate system rotating with the blade | θ _I -Α _I | (However, α _I = Tan ^-1 (U _I / RΩ), U _I 3. The flow velocity of the liquid sucked into the moving blade when viewed from a stationary coordinate system, the radius of the moving blade, and Ω is the angular velocity of the moving blade) is greater than 0 degrees and 20 degrees or less. Micro bubble generation pump. The angle θ with respect to the circumferential direction of the moving blade at the edge on the one end side of the plurality of blades _F The microbubble generating pump according to claim 1, wherein is 60 degrees or more and 90 degrees or less. The stationary vane is composed of a cylindrical main body and a plurality of wings provided on the outer peripheral surface of the cylindrical main body, and the plurality of wings are vertically cut on the outer peripheral surface of the cylindrical main body. 2. The microbubble generating pump according to claim 1, wherein the microbubble generating pump is provided so as to bend as it goes from one end of the cylindrical main body to the other end to which the swirl flow is supplied. The angle with respect to the circumferential direction of the stationary blade at the edge on the one end side of the plurality of blades is selected so that the swirl flow supplied from the moving blade does not separate from the plurality of blades. Micro bubble generating pump. 6. The microbubble generating pump according to claim 5, wherein the plurality of blades are configured such that no gap appears when projected in the direction of the central axis. The stationary blade has an air supply hole provided in one of the plurality of blades and an injection hole provided in the other end of the cylindrical main body, and the air supply hole and the injection hole 6. The microbubble generating pump according to claim 5, wherein said microbubble generating pump communicates with each other through a passage provided in said cylindrical main body. The vortex breakdown nozzle has a contraction part and a vortex breakdown part, and the microbubbles are generated from the vortex breakdown part by supplying the swirl flow into which the gas is introduced into the contraction part. The microbubble generating pump according to 1. The vortex breakdown part has a first part having a cylindrical shape and a second part having a shape spreading toward the outlet, and an inner peripheral surface of the first part and an end face of the second part are The angle formed is θ ₀ 0 degree <θ ₀ The microbubble generating pump according to claim 9, wherein the angle is 180 degrees, and the inner peripheral surface of the first portion and the end surface of the second portion are smoothly connected. 2. The microbubble generating pump according to claim 1, further comprising another moving blade and another stationary blade arranged sequentially coaxially from the suction port toward the discharge port on the suction port side of the moving blade. The other moving blade comprises a cylindrical main body and a plurality of wings provided on the outer peripheral surface of the cylindrical main body, and the plurality of wings cut longitudinally on the outer peripheral surface of the cylindrical main body. And the other stationary blade is provided between the cylindrical body and the cylindrical body. A plurality of wings provided on the outer peripheral surface, the plurality of wings are provided on the outer peripheral surface of the cylindrical main body so as to be longitudinally cut in the direction of the central axis of the other stationary blade, The rotor blades are composed of a cylindrical main body and a plurality of blades provided on the outer peripheral surface of the cylindrical main body, and the plurality of blades are vertically cut on the outer peripheral surface of the cylindrical main body, and The curvature of the cylindrical main body from one end to the other end on the liquid outlet side The stationary blade includes a cylindrical main body and a plurality of wings provided on the outer peripheral surface of the cylindrical main body, and the plurality of wings are arranged on the outer peripheral surface of the cylindrical main body. 12. The microbubble generating pump according to claim 11, wherein the microbubble generating pump is provided so as to bend in a longitudinal direction, and to bend from one end portion on the liquid inflow side toward the other end portion of the cylindrical main body. The moving blade is composed of a truncated cone-shaped body whose cross-sectional area increases in a direction from the suction port toward the discharge port, and a plurality of blades provided on the outer peripheral surface of the truncated cone-shaped body. The wing is provided so as to be longitudinally cut on the outer peripheral surface of the frustoconical main body and to bend as it goes from one end portion on the liquid inflow side to the other end portion of the frustoconical main body. The microbubble generating pump according to claim 1. There is a pressure blocking nozzle provided on the downstream end face side of the vortex breakdown nozzle so as to face and coaxially with the vortex breakdown nozzle, and the downstream end face of the vortex breakdown nozzle and the pressure blocking nozzle A gap is formed between the upstream end face and the gap increases radially from the central axis of the vortex breakdown nozzle and the pressure blocking nozzle, and the vortex breakdown nozzle of the pressure blocking nozzles The portion facing the outlet of the vortex breakdown nozzle is configured to shut off the low pressure portion at the center of the swirling flow coming out of the outlet of the vortex breakdown nozzle from the downstream side of the pressure blocking nozzle. The microbubble generating pump according to claim 1, wherein a portion of the vortex breaking nozzle facing the outlet is not penetrated into the outlet of the vortex breaking nozzle. The casing is configured to increase toward the moving blade after the sectional area of the casing decreases from the suction port toward the moving blade and becomes the minimum sectional area,
Gas is introduced from the outside into the casing in the portion between the suction port and the rotor blade,
The microbubble generating pump according to claim 1, wherein vortex breakdown is caused in a portion between the suction port and the moving blade of the casing. Inside the casing, it has a moving blade, a stationary blade and a vortex breakdown nozzle arranged sequentially coaxially from the suction port toward the discharge port,
Supplying the liquid sucked from the suction port to the moving blade to generate a swirling flow;
The stationary vane is composed of a cylindrical main body and a plurality of wings provided on the outer peripheral surface of the cylindrical main body, and the plurality of wings are vertically cut on the outer peripheral surface of the cylindrical main body. And it is provided so as to bend as it goes from the one end portion on the side where the swirl flow of the cylindrical body is supplied to the other end portion,
The swirling flow is supplied to the stationary blade, a gas is introduced into the center of the swirling flow at the stationary blade or the latter stage of the stationary blade, and the swirling flow into which the gas has been introduced is supplied to the vortex breaking nozzle to be swirled. A microbubble generating pump moving blade used in a microbubble generating pump that generates microbubbles by causing collapse and discharges the liquid from the discharge port together with the liquid,
It consists of a cylindrical main body and a plurality of wings provided on the outer peripheral surface of the cylindrical main body, and the plurality of wings cut vertically on the outer peripheral surface of the cylindrical main body and the cylindrical shape. The angle of the main blade of the plurality of blades with respect to the circumferential direction of the moving blade is set to bend from the one end portion on the liquid outlet side toward the other end portion. A moving blade for a microbubble generating pump selected so that the flow of the liquid supplied to the moving blade does not separate from the plurality of blades. Inside the casing, it has a moving blade, a stationary blade and a vortex breakdown nozzle arranged sequentially coaxially from the suction port toward the discharge port,
Supplying the liquid sucked from the suction port to the moving blade to generate a swirling flow;
The moving blade is composed of a cylindrical main body and a plurality of wings provided on the outer peripheral surface of the cylindrical main body, and the plurality of wings run vertically on the outer peripheral surface of the cylindrical main body. And it is provided so as to bend as it goes from the one end portion on the liquid outlet side of the cylindrical main body to the other end portion,
The swirling flow is supplied to the stationary blade, a gas is introduced into the center of the swirling flow at the stationary blade or the latter stage of the stationary blade, and the swirling flow into which the gas has been introduced is supplied to the vortex breaking nozzle to be swirled. A microbubble generating pump stationary blade used for a microbubble generating pump that generates microbubbles by causing collapse and discharges the liquid from the discharge port together with the liquid,
It consists of a cylindrical main body and a plurality of wings provided on the outer peripheral surface of the cylindrical main body, and the plurality of wings cut vertically on the outer peripheral surface of the cylindrical main body and the cylindrical shape. The angle of the plurality of blades with respect to the circumferential direction of the stationary blade at the edge on the one end portion side is provided so as to bend from the one end portion on the side to which the swirl flow is supplied toward the other end portion. A stationary blade for a microbubble generating pump selected so that the swirl flow supplied from the moving blade does not separate from the plurality of blades. Inside the casing, it has a moving blade and a vortex breakdown nozzle sequentially arranged coaxially from the suction port toward the discharge port,
A suction plate having a through hole in the center is provided coaxially with the moving blade and the vortex breaking nozzle so as to close the suction port at the suction port of the casing,
The moving blade comprises a vortex impeller having a diameter smaller than the inner diameter of the casing,
Supplying the liquid sucked from the through hole of the suction plate provided in the suction port to the vortex impeller to generate a swirl flow,
A gas is introduced into the center of the swirling flow, and the swirling flow into which the gas has been introduced is supplied to the vortex breakdown nozzle to cause vortex breakdown, thereby generating microbubbles and discharging the liquid together with the liquid from the discharge port. Microbubble generation pump. The microbubble generating pump according to claim 18, further comprising a stationary blade between the vortex impeller and the vortex breakdown nozzle.