JP2000000563A - Apparatus and method for improving liquid quality - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve liquid quality by accelerating the destruction of bacterial cells or deactivation of bacteria by positively utilizing cavitation bubbles by forming liquid jet streams in a closed space such as a rectangular box or a cylindrical space and generating liquid jet streams and generating vortex streams in the jet streams and generating dynamic vortex streams in the vortex streams. SOLUTION: A liquid quality modifying apparatus 1 is constituted of a turbulent flow generation box 2 and a duplex nozzle 3. The duplex nozzle 3 is constituted of a cavitation generation part 5 and a gas-liquid introducing part 6. Further, the cavitation generation part 5 is formed in the turbulent flow generating box 2 and the gas introducing part 6 is formed of a liquid introducing part 7 and a gas introducing part 8. A jet hole 14 is opened to one side wall of the turbulent flow generation part 2 and an axial liquid introducing port 15 and a radial liquid introducing port 16 are opened to the liquid introducing part 7 and an axial gas introducing hole 18 is opened to the gas introducing part 8 and a cavitation generating nozzle is formed by the jet hole 4 and the axial liquid introducing hole 15. A liquid discharge port 19 is opened to the other side wall of the turbulent flow generation box 2.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a liquid quality reforming apparatus and method for performing degassing, mixing, stirring, sterilization, insecticide, decomposition, emulsification, and the like of a liquid using cavitation. More specifically, cavitation is actively generated by ejecting liquid, destroying biological cells by the action of cavitation erosion, degassing of dissolved gas such as harmful chlorine gas in liquid, mixing of substances into liquid, The present invention relates to a liquid quality reforming apparatus and a liquid quality reforming method for reforming liquid quality such as stirring, sterilization of bacteria in a liquid, killing of parasites, decomposition of organic matter, emulsification of oil, and the like.

[0002]

2. Description of the Related Art Techniques for separating and destroying gas and various bacteria in a liquid to reduce the specific effects of the gas, various bacteria, etc., for example, blue-green algae in lake water, cells of the genus Legionella in drinking water and bathtub water. There is a need for effective techniques such as eliminating the activity and removing chlorine dissolved in tap water. In addition to the Legionella spp. In the natural environment that lives in fresh water such as soil, ponds and swamps, lakes, and rivers, cooling tower water for air conditioning, irrigation water, cutting oil, and water in home and commercial water heaters , Fountains in parks, water in ultrasonic / distillation humidifiers, water for circulating whirlpools (so-called 24-hour baths), spray water for dental treatments, and artificial environment growing in multipurpose water in hospitals In particular, there is a particular need to inactivate the physiological and cellular activities of Legionella spp.

[0003] As of 1996, more than 40 species of such Legionella spp. Are known (0.3-0.7).
(2-5) Gram-negative micron of micron, but it is aerobic and easily proliferates in water that comes into contact with the air, not only adversely affecting the human body, but also proliferating in ultrapure water for semiconductor production. This has reduced the yield of semiconductor manufacturing. The culture time of Legionella spp. Is much longer than that of Escherichia coli, and it takes a lot of time to confirm the existence of Escherichia coli. A facultative intracellular bacterium that coexists with green algae, uses extracellular metabolites as a carbon source and energy source, and proliferates in the cells of protozoa such as macrophages in the body and amoeba living in the same environment. There is a particular need for effective elimination of Legionella spp.

[0004] On the other hand, it has been proposed to use jet cavitation for destroying blue-green algae and the like. Aoko with the impact when the jet stream hits the impact plate,
Although a device for disabling harmful phytoplankton called freshwater red tide has been put into practical use, a technology for disabling biological activity has just begun. The physical activity due to cavitation has been known for a long time, as shown by a series of physical and technical idioms called cavitation erosion.

[0005] Sea water or water for ikesu, fish farming equipment, etc.
It contains gases mainly composed of various components in the air. It contains various components in air that is a gas at normal temperature, such as oxygen, nitrogen, and carbon dioxide. In addition, harmful ammonia emitted by fish is converted to nitrite (HN)
It is known to be a component such as O ₂ ), nitrite and nitrate. Deep seawater is rich in mineral nutrients, phosphates and silicates necessary for plant growth. In the case of fresh water such as tap water, it contains chlorine and the like for disinfection.

[0006] Since these substances are generally harmful to organisms in water, it is desirable to remove them as much as possible or to change them into stable salts which do not affect the organisms. However, it is practically impossible to stabilize or selectively adsorb these harmful substances with chemicals by neutralization or the like with a fish culture apparatus having a limited capacity.

[0007] That is, if a small amount of a chemical for removal remains, it is concentrated in living organisms, leaving an adverse effect. Due to these problems, onshore aquaculture equipment is disposed of in a short time without pumping and recycling a large amount of seawater. For this reason, it consumes energy and causes polluting seawater in the near sea.

[0008] Cavitation also has the ability to destroy objects, as is known from eroding the metal surfaces of turbine blades. While the destruction of cavitation is disliked, techniques that try to exploit it are only exceptionally known,
Not common. As a result, their research has been delayed. Cavitation and the vortex of a high-speed jet fluid are analyzed by the dynamics of a complex system, and they are inexperienced in learning.Theoretical results have already been determined while incorporating the results of trial and error research. It is preferable to proceed with engineering and practical development in conjunction with the results of research that has been conducted.

[0009] Techniques based on such research exist in advance. The prior art shown in Japanese Patent Application No. 10-316020 of the same inventor makes air introduction an important technical matter. However, the active introduction of such air,
Subsequent demonstration experiments have revealed that it is rather inappropriate for the purpose of cell destruction and gas-liquid separation. In this specification, cavitation, cavitation bubbles, and cavitation bubbles are used synonymously. In addition, cavitation flow and eddy current are used synonymously. Furthermore, erosion and erosion are used synonymously.

[0010]

SUMMARY OF THE INVENTION The present invention has been made based on such a technical background, and achieves the following objects. An object of the present invention is to provide a liquid quality reforming apparatus and a liquid quality reforming method for effectively utilizing cavitation bubbles to efficiently destroy cells or invalidate cell activity. Another object of the present invention is to provide a liquid quality reforming apparatus and a liquid quality reforming method for efficiently separating gas dissolved in a liquid by actively utilizing cavitation bubbles.

Still another object of the present invention is to provide a liquid quality reforming apparatus and a liquid quality reforming method which achieve the above object more effectively by forming a vortex of cavitation bubbles. It is still another object of the present invention to provide a liquid quality reforming apparatus and a liquid quality reforming method that achieve the above object more effectively by moving the vortex of cavitation bubbles. Still another object of the present invention is to provide a liquid quality reforming apparatus and a liquid quality reforming method for efficiently degassing unnecessary gas in a liquid by mixing a gas such as air into a liquid after cavitation. Is to provide.

Still another object of the present invention is to clarify theoretical and experimental mathematical conditions for enhancing the cavitation effect, to facilitate the use of the technology, to efficiently nullify cell activity, to remove impurities, An object of the present invention is to provide a liquid quality reforming apparatus and a liquid quality reforming method for degassing a gas in a liquid. Still other objects of the present invention will be more specifically described below through embodiments.

[0013]

The liquid quality reforming apparatus and the liquid quality reforming method according to the present invention employ the following means to solve the above-mentioned problems. A liquid jet stream is formed in a closed space such as a rectangular box main body or a cylindrical space, a vortex is generated in the jet stream, and a dynamic vortex is generated in the vortex stream. Dynamic is movement of the central region of the vortex.

The movement of the central region is a geometric movement, but not a physical movement. Water molecules that form eddies are
Although it has a violent spiral motion, the motion of the central region and the motion of the water molecule have substantially no relation. Such movement of the central region is similar to movement of a typhoon. The motion in these closed spaces is also referred to as a turbulence generating unit or a turbulence generating means in the present invention.

The motion of the center of the vortex of the cavitation bubble is described by a complicated equation of motion having the inner surface of a closed space such as a box or a cylinder as a boundary condition. Has formed. A myriad of tiny bubbles have a boundary surface of, for example, a pressure near the spherical surface.
The stress gradient is very large and changes rapidly with time. A cell that comes into contact with a liquid having a pressure / stress gradient showing such a temporal change instantly loses its cell activity. The pressure gradient also promotes the vaporization of the gas in the liquid, creating new seeds of bubble generation, and consequently the gas-liquid separation.

The eddy current as a whole proceeds from an inlet provided in a box body or a container such as a cylinder to an outlet, and a vortex is formed in the course of the eddy current. This eddy current is macroscopic, with one in principle occurring per outlet. Microscopically, countless vortices are observed at the beginning of vortex generation,
The sum of the respective angular momentums of all water molecules appears as one angular momentum. The central region of such a vortex is also quadratic in nature, and in a closed system, ie under the described boundary conditions,
Perform a periodic closed motion.

Under the initial conditions such as the incident velocity of the jet flow causing the vortex motion, the nozzle shape for appropriately distributing the jet nucleus, and the above-described boundary conditions, shear stress acts on the vortex flow at the same time, and cavitation occurs. It is also a condition. In other words, it can be said that the generation of the vortex of the foam defines the generation of cavitation appropriate for cell destruction.

It is more effective to generate cavitation if the nozzle is formed as a single nozzle so as to introduce only a liquid such as water or seawater at least for the generation of cavitation and does not actively introduce air. ,
Excellent for cell destruction, gas degassing, mixing, etc. However, for some purposes, the nozzle may be water,
Alternatively, it may be formed as a double nozzle having a first nozzle for introducing a liquid such as seawater and a second nozzle for introducing a gas such as air or a liquid.

In this case, in order to give priority to the occurrence of cavitation, the second nozzle should be plugged in order to lose its function, or be plugged with a valve capable of controlling the flow rate and capable of completely shutting off. I just need. By making the stopper detachable, the box, tube, and the like can be used for other purposes. The discharge pressure for supply to the nozzle is selected and selected from the range of ² kg / mm ² or more depending on the application and effect. Desirably, the deaeration of chlorine in tap water should be 2 kg / mm ² or less.
Mixing, separation and sterilization may be 10 kg / mm ² or less, degassing and sterilization may be 30 kg / mm ² or less, and the decomposition of organic substances such as trichlorethylene and dioxin is desirably 100 kg / mm ² or more.

Preferably, the boundary condition of the turbulence generating portion is
The inner space is flat. Being flat is
This is a condition in which a vortex having a certain angular momentum is not three-dimensionally rotated (the angular momentum, which is a vector, has a direction of a rotation center axis perpendicular to a plane), and this condition stabilizes the vortex flow.
In order to smoothly move the eddy current, it is effective to provide a turbulence generating portion having a curved surface in the direction of the motion. Such a vortex has strong shear stress and promotes the collapse of the foam, which generates a shock wave in the liquid.

If the approximate height of the internal space is denoted by H, its approximate width is denoted by W, and the effective diameter of the nozzle opening is denoted by D1, the jet flow is directed in the longitudinal direction and Injected in the direction of the approximate center line. Suitable conditions for the generation of the vortex are D1 <H and W / H> 4. Is represented by This is an empirical formula but has a theoretical basis.

The nozzle comprises a downstream flow path and an upstream flow path. That is, cavitation occurs in the liquid that suddenly enters the wide passage from the narrow passage. The effective diameter of the downstream channel is D
When the effective diameter of the upstream flow path is represented by D2 and the effective length of the downstream flow path is represented by L in 1, the suitable conditions for generating the vortex are L / D2 ≧ 5 and D1 / D2 ≧ 2. . Is represented by This is an empirical formula but has a theoretical basis. More preferably, it is represented by the following formula. L / D2 ≧ 8 and 4 ≧ D1 / D2 ≧ 3. It is preferable that the opening of the nozzle forming the outlet or the cross-sectional shape of the nozzle is circular. However, the opening is not necessarily circular and may be elliptical or polygonal.
The fluid in the present invention does not have to have a streamline that is a so-called streamline, that is, it is not for rectification, but for generating cavitation, and has a locally thorough eddy current.
It is only necessary that the eddy current is synthesized globally.
The effective diameter D is approximately given by S = π (D
Is represented by the following relationship:

[0023]

[First Embodiment of Liquid Quality Reforming Apparatus]
Next, Embodiment 1 of the liquid quality reforming apparatus according to the present invention will be specifically described. FIG. 1 shows an embodiment of a liquid quality reforming apparatus according to the present invention. The liquid quality reforming apparatus 1 includes a turbulence generating box 2 and a multiple nozzle 3. The multiple nozzle 3 includes a cavitation generation section 5 and a gas-liquid introduction section 6. The cavitation generating section 5 is formed on the turbulence generating box 2 itself, as described later in detail.

As shown in FIG. 2, the gas-liquid introduction section 6 includes a liquid introduction section 7 and a gas introduction section 8. The gas-liquid introduction unit 6 is fixed to the turbulence generation box 2. The fixing means for fixing is, for example, a bolt hole 11 (see FIG. 1).
And bolts (not shown). The gas inlet 8 is fixed to the liquid inlet 7.

The fixing means comprises, for example, a bolt hole 12 formed in the liquid introduction section 7 and a bolt 13 formed in the gas introduction section 8. A packing or O-ring 10 is interposed between the liquid introduction part 7 and the gas introduction part 8 in order to prevent liquid leakage from between the liquid introduction part 7 and the gas introduction part 8 which are detachable. ing.

If the gas inlet 8 is removed and a plug (not shown) is screwed into the bolt hole 12 of the liquid inlet 7 instead, the dual nozzle 3 can be easily changed to a single nozzle. Although the gas-liquid introduction part 6 as shown in the figure forms the double nozzle 3, it can be modified to a single nozzle that ejects only liquid. The gas introduction unit 8 is for introducing not only gas at room temperature such as air and oxygen, but also liquid surfactants, oils, and the like, fine powders of foods and the like, and a mixture of gas and liquid. is there. Therefore, the gas introduction part 8 here does not mean introduction of only gas.

The internal space V in the turbulence generating box 2 is approximately
It is a flat rectangular parallelepiped. The physical and geometric significance of flat is
It will be described in detail later. The turbulent flow generation box 2 having a longitudinal center line CL passing through the center point of the internal space V as an axis line has a substantially rectangular parallelepiped appearance, and has a six-sided wall. A jet hole 14 having a diameter D1 is formed in a side wall of the turbulence generation box 2. The jet hole 14 coincides with the cavitation generating section 5. The axis of the jet hole 14, which is the cavitation generating section 5, coincides with the longitudinal center line CL.

The liquid introduction part 7 has an axial liquid introduction hole 15.
And a radial liquid introduction hole 16. The axial liquid introduction hole 15 and the radial liquid introduction hole 16 are connected at an axial center. A high-pressure liquid introduction pipe (not shown) is connected to an outer opening of the bolt hole 12. Axial liquid inlet 1
The above-mentioned bolt hole 12 is formed in an extension portion formed by extending the rear portion 5. The gas introduction part 8 is inserted in the axial liquid introduction hole 15 and its extension part, sharing the longitudinal center line CL as the axis.

The gas introducing portion 8 has an axial gas introducing hole 18 sharing a longitudinal center line CL as a center line. Axial liquid inlet 15 and axial gas inlet 18
Have the same opening surface and are opened at the rear end of the jet hole 14 and connected to the jet hole 14. The width of the internal space V is shown in FIG.
, And its height is H shown in the figure, and its length is not particularly defined. The length direction of the internal space V is defined as the axial direction of the jet hole 14.

The height H and width W of the internal space V, the diameter D1 of the jet hole 14, and the diameter D2 of the axial liquid introduction hole 18 are shown in FIG.
4 is conceptualized and defined. A nozzle for generating cavitation is formed by the jet hole 14 and the axial liquid introduction hole 15. The internal space V is partially open at the inlet corresponding to the nozzle and the outlet 19 (see FIG. 1), but the internal space into which the high-pressure fluid is introduced may be treated as a substantially closed space. it can. That is, the six-sided walls forming the rectangular parallelepiped internal space V define boundary conditions.

As is generally known, the condition for generating cavitation is L / D2, especially when the liquid is water.
≧ 5. L is the axial length of the jet hole 14. This relationship is less affected by the viscous drag of the liquid. Such a relationship is a relationship (reverse relationship) that has been conventionally studied to suppress the occurrence of cavitation. In order to actively generate cavitation,
Preferably, L / D2 ≧ 8.

Further, the cavitation occurrence condition must satisfy the following relationship. D1 / D2 ≧ 2. This relationship is also a relationship (reverse relationship) that has been studied for suppressing cavitation. In order to positively generate cavitation, preferably, 4 ≧ D1 / D2
≧ 3. Qualitatively speaking, the conditions for cavitation are:
High-speed high-pressure fluid rapidly flows from a narrow place to a wide place. Cavitation does not occur wherever Bernoulli's theorem holds.

The cavitation flow is also generated in a wide area when the fluid is swirled like a typhoon. The countless bubbles (cavitation) generated near the jet nucleus at the exit of the jet hole 14 eventually disappear. If a vortex is generated, the bubbling continues. Due to the shear force of the vortex, the bubbles become seeds for producing other bubbles. That is, the bubbles generated from the nozzles become seeds and reproduce the bubbles in the vortex.

As is known, the condition for generating the vortex is such that the size of the space constituting the turbulence generating portion is D1 <H and W
/ H> 4. That is, if the height H is large, the vortex does not continue even if it occurs once, and is immediately destroyed and disappears.
This is because a vortex having angular momentum is not stabilized in a three-dimensional space but is stabilized in a plane. As will be described later, the central region of such a vortex orbits in a plane orthogonal to the height direction along substantially the entire inner space along the four-sided walls except the upper and lower two-sided walls. That is, the entire liquid in the internal space has angular momentum at a speed slower than the rotation speed of the vortex center while a part of the liquid is discharged from the discharge port.

It is effective if the internal space constituting the turbulence generating section is substantially flat. Instead of the single type (single) nozzle, a double type nozzle may be used to introduce air bubbles into the liquid by the gas introduction unit 8 and mix the air bubbles into the cavitation flow. In situations where cavitation is occurring,
The pressure gradient becomes extremely large spatially in the area around the bubbles, and the decomposition and separation, mixing, emulsification, and stirring of substances dissolved in the liquid near the cavitation bubbles, gas separation, and conversely, gases such as oxygen Can also be dissolved.

The liquid quality reforming apparatus according to the present invention is used together with a high pressure pump. A plunger pump is suitable as a high-pressure pump so that the pressure near the outlet can be increased. The supply pressure to the nozzle is 2 kg / m depending on the application and effect.
choose and select from m ² or more of the range. Desirably, degassing of tap water chlorine is 2 kg / mm ² or less, and stirring, mixing, separation,
Sterilization may be 10 kg / mm ² or less, and degassing and sterilization may be 30 kg / mm ^2.
Decomposition of organic substances such as trichlorethylene and dioxin is preferably in the range of 100 kg / mm ² or more.

The cavitation vortex can be formed by designing the liquid quality reforming apparatus 1 to have, for example, an inner space having a width of about 7 cm, a length of about 15 cm, and a height of about 2 cm. FIG. 21 is an abstract drawing that abstracts a photograph of a spouted bed in which cavitation has occurred in the turbulence generation box 2 taken by a high-speed camera. The direction of rotation of the vortex is determined by initial conditions due to slight asymmetry of the direction of the nozzle, and the direction of the spin axis is preserved by the law of conservation of angular momentum of the whole system. The vortex has a central portion 31. The central portion 31 moves on a closed trajectory line 32 oriented in a certain direction. For example, it makes one round on the trajectory line 32 in two seconds.

FIG. 22 shows a state in which the central portion 31 of the vortex moves about half way around the trajectory line 32 shown in FIG. The cavitation bubbles are also in the vortex before contracting and expanding, especially expanding and collapsing. The physical activity (pressure fault) of such a foam performs actions such as destruction of the cell membrane of bacteria in the liquid, decomposition of the substance, mixing, and miniaturization. In addition, the dissolved gas in the liquid, such as methane or other organic solvent, or an impurity gas such as chlorine, is induced by the rapid expansion of the foam, flows out into the pressure fault, evaporates in the foam, is released from the outlet 19, and the pressure is reduced. Released into the atmosphere in a state. A violent vortex is generated around the center of the vortex orbiting in the internal space V, and the vortex agitates the liquid uniformly in the space.

Next, in order to facilitate understanding of cell destruction by cavitation, the theoretical background will be described for reference. It has long been known that a jet is described by an equation of motion based on shear stress (Reynolds stress). The specific theoretical development has been carried out by the present inventors (published).

FIG. 5 is a plan sectional view for analyzing a free vortex jet discharged from a nozzle into a vacuum. The x-axis is set to coincide with the center line of the virtual nozzle 51 (a portion near the ejection port is formed as a conical surface for virtualization). The y-axis is set in the direction in which the jet spreads, that is, in the direction orthogonal to the direction of travel of the jet center. Therefore, the coordinate system xy is a rectangular coordinate system. When the conical surfaces of the nozzle 51 are extended and the surfaces intersect, a tip of the conical jet flow core 52 is generated. The spread of the jet at a position X sufficiently distant from the jet flow core 52 is indicated by b. As an empirical formula, b = k # j · x (1) In this specification, a subscript right subscript is preceded (left side) by #. k # j is called a jet divergence coefficient and is an important basic factor of jet characteristics.

In the case of having the eddy current characteristic, b = 24 k · x (2) The constant k is a coefficient representing the eddy current characteristic. The shear stress τ is expressed by the following expansion formula, that is, a polynomial.

[0042]

(Equation 1) The coefficient C # n is determined from the shear stress for the boundary condition of the equation of motion. Applying Prandtl's assumption on the Reynolds stress, the velocity distribution is expressed by the following equation in an approximate expression up to the fourth order.

[0043]

(Equation 2) Equation (3-1) derived from the conditions of the shear stress can be applied to any of the two-dimensional and three-dimensional flows of the free jet and the restricted jet. The value of η at which the right side of equation (3-1) is 0 is 1
Therefore, the jet velocity becomes zero at a position away from the x-axis by a certain distance.

When the liquid is discharged from the nozzle 51 having a finite exit cross-sectional area having a diameter D into an infinite space, when there is no pressure gradient, that is, the velocity decay of the jet on the central axis is determined by the law of conservation of momentum.

(Equation 3)

Since the speed at the nozzle outlet is zero on the central axis, the speed rapidly increases after the outlet, and as shown by arrows in FIG. Velocity vectors at positions apart from each other appear symmetrically. The jet is divided into a range up to the length X # c of the jet nucleus, that is, an initial region 53 and a range downstream thereof, that is, a main region 54. Calculating for reference, the length of the jet core is

(Equation 4)

Equations (4, 5) follow the experimental results of Albertson. From equation (4,5), the jet core length X #
c is obtained, and the jet spread coefficient k # j of Expression (1) is obtained from Expression (6). Therefore, the coefficient k of Expression (2) can also be obtained. Experimentally, the jet nucleus length X # c is determined by measuring the velocity u # m above the jet center, and the jet width b and the jet spread coefficient k # j are obtained.

Cavitation phenomena in a high-speed underwater water jet can be considered based on the above analysis. Rous
It can be estimated as follows from the viewpoint of the eddy current characteristics of the airflow jet by e. The eddy viscosity coefficient ε of the free jet is given by: ε = kbu # m (7) The coefficient k relating to the eddy current characteristic is given by Prandtle's assumption.

(Equation 5)

According to equations (8, 9), b is proportional to x and u #
a three-dimensional flow in which m is inversely proportional to x (the relationship of equation (4)), and b
Is proportional to x and u # m is inversely proportional to the square root of x (relationship of equation (5)). For each jet of a two-dimensional flow, equation (3-
1) is obtained. The coefficient k can be obtained by calculation from the energy equation.

[0049]

(Equation 6) The Reynolds stress τ, which is closely related to the cavitation phenomenon, is

(Equation 7) When the eddy current diffusion coefficient 大 き い is large, the diffusion of energy that causes the cavitation effect is easily caused. As the jet spread coefficient k # j appears linearly in Equations (10, 11), it directly affects the promotion of the cavitation effect. This means that when the jet is confined due to a wall around the nozzle, the jet spread coefficient k # j changes.

A jet model having a horn-type side wall is known as a model that causes a constrained jet flow.
As shown in FIG. 6, when the jet spread coefficient k # j in the case where the conical side wall shown by the dotted line, that is, the constraining wall 55 is provided, the three-dimensional

(Equation 8) This is the same in the two-dimensional case. The significance of equation (12) is that a relationship between the jet spread coefficient k # j and the side wall angle θ # w is obtained. For a two-dimensional flow in a flat rectangular box and a three-dimensional flow in a cylindrical box, the maximum velocity u of the jet is
#M has a difference of attenuating at the square root of x or attenuating in proportion to x. In the present invention, a two-dimensional flow formed in a flat box is used so that the attenuation is small. I have. Moreover, the two-dimensional flow has good stability as described above.

When the cavitation initiation coefficient σ # i is represented by a graph from the equations (10) and (12), as shown in FIG. 7, the maximum value is obtained when θ # w is around 30 degrees. This graph is quoted from Numachi's experimental report (Hayaken Report, Vol. 16, 1960-1961, No. 158, No. 159). Theoretical analysis excerpted as described above in this specification (“About the basic characteristics of jets”, Jet Engineering Vol.
12, No. 2, 1995, 23-32) by Yanaida (directly below), showing good agreement between theory and experiment.

FIG. 8 shows the relationship between the ratio of D and d shown in the figure and the cavitation initiation coefficient σ # i. That is, the cavitation initiation coefficient σ # i is determined by the ratio (D / d)
(This is the maximum at around D1 / D2 in FIG. 3). Therefore, if D1 is three times the unit length, L is preferably eight times the unit length. It is empirically preferable to set the following for a multiple nozzle.

[0053]

(Equation 9) Here, d1 and d2 are the inside diameter and the outside diameter of the plurality of nozzles (see FIG. 2). If d2 is zero, in such a case, for example, it is preferable to be expressed by the following equation.

[0054]

(Equation 10) For the width B and height A, of course,

[Equation 11] Here, A coincides with W in FIG. These conditions are based on the premise that the Reynolds number is 2300 or more. From these equations, the range of the absolute values of those values is determined. If only the cavitation effect is considered, the values W, B, and H may be small, but the volume of the box needs to be somewhat large in consideration of the eddy motion and the purification efficiency.

The attachment distance X # R of the jet is expressed by the following equation using d in FIG. 9, the jet spread coefficient k # j, and the side wall angle θ # w.

(Equation 12) Note that the calculation results are shown for reference.

(Equation 13)

FIGS. 9 and 10 show experimental results showing cavitation erosion (“Hydraulics of Pipelines”;
Paul Tullis, JOHN WILEY & SONS, 1989, P17
0). X # cp indicates the region where cavitation erosion occurs, that is, the x coordinate in the middle of the cavitation pitching zone. FIG.
The relationship between the coordinates of the ultrasonic maximum generation position and the side wall angle θ # w is shown. The results of these two experiments prove that the existence of the specific region where cavitation erosion occurs substantially coincides with the existence of the specific region where ultrasonic waves are generated.

FIGS. 9 and 10 also show the core length X # c according to the study in the square. As shown in FIG. 10, the maximum position of the cavitation ultrasonic wave substantially corresponds to the square core length. As shown in FIG. 9, the collapse test of orifice cavitation corresponding to the rapid expansion is almost in agreement with the study in the square. The cavitation effect, in which the shear stress τ, the eddy current diffusion coefficient χ, and the jet core length are closely related, is promoted by giving appropriate dimensions to the nozzle shape and box shape.

The shapes of the nozzles are classified into types as shown in FIGS. 11 to 14, but the present invention is in principle irrelevant to the types of such nozzle types. The nozzle 23 shown in FIG. 14 in which a small-diameter jet hole is opened at the side wall surface perpendicular to the axis of the cylindrical surface container is the most fundamental nozzle 23, and the nozzle 23 shown in FIG. Nozzle 22, a nozzle 20 shown in FIG. 11 in which a conical surface is formed following a wall perpendicular to the axis, which is a compromise between those shown in FIGS. 13 and 14, and a nozzle shown in FIG. 12 in which the jet holes themselves form a conical surface 21 types.

As described above, the cavitation generation region, its degree, and the like can be analyzed globally from the equation of motion of the shear stress based on the momentum distribution described on the coordinate system with the core nucleus as a unit, and the analysis is simple. It was shown to be. Next, a local study on one cavitation bubble is also required.

There are also reports to note the relationship between the air content and the cavitation initiation coefficient. 12th International Towing
According to an experimental report released at the Tank Conference (ITTC),
This means that if the state of the cavitation nuclei contained in the experimental water is different, the state of cavitation changes significantly. Figure 15 (R. Oba et al., Cavitation-Nuclei Me
asurements by a Newly Made Coulter-Counter without
Adding Salt in Water, Rep.Inst.High Speed Mech.,
Tohoku University, Sendai, 43-340 (1981), 173)
Shows the relationship between the diameter of underwater nuclei (air nuclei, chlorine nuclei, etc.) in tap water and the number of nuclei. The distribution of the nucleus diameter and its number 24 hours after the collection has changed significantly. Thus, the presence of cavitation nuclei in tap water is not stable.

FIG. 16 (Numachi's study) shows the relationship between the number of underwater nuclei (number density distribution) and the air content related to the nucleus diameter and the initial cavitation coefficient K. Regardless of the temperature change, the air content can significantly affect the primary cavitation coefficient (the definition is described in detail in Ryoji Kobayashi: Cavitation, Waterjet, 1-2 (1984, 1-13)). It is clearly shown. The numerator of the air content α / α # s is the actual air content,
α # s indicates the saturated air content.

Although cavitation looks like a white cloud when observed with the naked eye, it can be seen from high-speed photography and instant photography that cavitation is formed from moving bubbles and cavities fixed to the solid surface. Looking at the temporal fluctuation of bubbles, a bubble has a lifetime, has a growth period and a disappearance period, and may be accompanied by a rebound process after disappearance. Rayleigh's Theory (1
According to 917), assuming that one spherical vapor bubble is in a sufficiently wide still space, the maximum pressure generated near the bubble when the bubble disappears from the initial radius R # 0 to the radius R is lost. The value p # max is represented by the following equation.

[0063]

[Equation 14] p # ∞ is the pressure of the surrounding space. Assuming that the bubble radius R is 1/20 of the initial radius, the maximum pressure is 1280 times the pressure of the surrounding space. The theoretical value of the pressure distribution p (r) in the radial direction when one vapor bubble containing a small amount of gas disappears and rebounds and its time change shows a sharp pressure rise that is seen as a shock wave during the rebound period. .

This has been confirmed by schlieren photography. It has been recognized that the impact pressure generated during the bubble extinction / rebound period is an important cause of the mechanism for describing cavitation erosion. One of the causes is the microjet theory, which is based on the assumption that the microjets are formed inside the disappearing cavitation bubbles.

FIG. 17 shows a numerical simulation of the extinction process of a spherical bubble on a solid surface, and shows how a microjet formed in the bubble hits the solid surface. Such a phenomenon has been confirmed by experiments.

Conventionally, cavitation research has been conducted from the viewpoints of material damage, cleaning of solid surfaces, and the like. However, the impact pressure fluctuation at the time of cavitation collapse is combined with the cavitation effect due to the active introduction of air. It has never been done for the technical means of destructive purification and separation. The impact pressure of the cavitation bubbles uniformly dispersed and diffused can effectively destroy cells and effectively separate gas and liquid.

The jet nucleus is also generated by the rotation of the rotor.
In this case, the air can be drawn into the jet stream generated from the surface of the rotor from a hole formed in a part of the hollow rotor. The effectiveness of cell disruption is less affected by air introduction. Spatial and temporal pressure gradients (dP / dx.
DP / dt). Cavitation occurs around the above-described core formed downstream from the nozzle outlet. The amount of cavitation and the shape and distribution of the core are not directly related. The amount of cavitation increases when the fluid flows from a small-diameter port to a large-diameter orifice at a high velocity.

FIG. 18 shows a known representative example of a stationary water jet nozzle. This nozzle is designed with attention to the angle of the nozzle contraction part (10 ° to 14 °) and the ratio (4 times) of the length of the outlet pipe to the diameter of the outlet (d0) so as to prevent cavitation. Is considered. 19 and 20 show nozzles designed to promote the occurrence of cavitation.

FIG. 19 shows a nozzle that generates a large amount of cavitation when it suddenly exits a wide area from a nozzle formed narrow by a rod 81 and an opening 82.
FIG. 20 shows a state in which the flow is constrained by a narrow jet port and ring-shaped (torus-shaped) cavitation bubbles are generated. Rather, as shown in the nozzles of FIGS.
It is advantageous for the occurrence of cavitation that the jet core (core) is not clearly present.

As for the cavitation, in addition to the nozzle-dependent type generated behind the jet nucleus found in the mathematical analysis described above, both the cavitation type and the vortex-dependent type generated due to the shear stress in the vortex are examined. Need to be Degassing,
Experiments have shown that the latter is effective for mixing, sterilization, decomposition, and the like. It is presumed that the former greatly affected the occurrence of the latter. The vortex shear stress may have a significant effect on cell destruction independently of cavitation. Thus, it cannot be denied that the occurrence of jet nucleus-dependent cavitation and the vortex-dependent cavitation, or the conditions under which they occur, are important factors for cell destruction.

[Second Embodiment of Liquid Quality Reforming Apparatus] In the first embodiment, the turbulence generating box 2 of the liquid quality reforming apparatus 1 is flat and box-shaped, and the internal space is rectangular. It had a space in the shape of a circle. Although this shape efficiently generates cavitation as described above, this shape is not necessarily required. FIG. 23 shows an embodiment 2 of the liquid quality reforming apparatus, in which the internal space of the turbulence generating section is cylindrical. At both ends of the cylindrical body 30, disk-shaped flanges 29 are arranged, and the cylindrical body 30 is inserted into a groove 33 formed on this end face.

The two flanges 29 and the cylindrical body 30 are connected to each other by bolts 34 and nuts 35 and are fixed to each other. On the side surface of one flange 29, a multiple nozzle 3 having the same shape as that of the first embodiment is arranged and fixed. One of the flanges 29 is formed with a cavitation generating portion 5 which is a cylindrical through hole. Further, as shown in FIG. 23, the gas-liquid introduction part 6 is formed of a liquid introduction part 7 and a gas introduction part 8, but the principle and function thereof are substantially the same as those of the first embodiment. Therefore, the description is omitted. However, similarly to Embodiment 1 described above, the gas introduction unit 8 does not have to be closed and used.

At the center of the other flange 29, a discharge port 36, which is a through hole, is formed. Furthermore, another flange 2
One end of a discharge guide cylinder 36a is fixed to the side surface of the pipe 9. The turbulent flow generation chamber 37 which is a cylindrical space in the cylindrical main body 30
Creates a space for turbulence such as collapse of cavitation bubbles and vortex flow. The turbulence generation chamber 37 performs physical and chemical actions such as sterilization, insecticidal, degassing, emulsification, and mixing.

[Third Embodiment of Liquid Quality Reforming Apparatus] FIG.
Shows a third embodiment of the liquid quality reforming apparatus,
7 is the same as the third embodiment, but differs in the mechanism for generating cavitation. This is an example in which an axial liquid introduction hole for conducting liquid and a cavitation generating section are arranged in a turbulent flow generation chamber 37. The axial liquid introduction hole 38 allows the pressurized liquid to pass therethrough, and injects the liquid to a cavitation generating section 39 formed concentrically to generate cavitation. This type of cavitation nozzle 40
Unlike Embodiments 1 and 2, the single nozzle type is used, and gas cannot be mixed. Cavitation nozzle 4
Since 0 protrudes inside, there is a feature that the whole becomes compact.

[Fourth Embodiment of Liquid Quality Reforming Apparatus] FIG. 25
Shows a fourth embodiment of the liquid quality reforming apparatus. The cavitation nozzle 40 and the turbulence generation chamber 37 are the same as those of the third embodiment, but differ in that the cavitation nozzle 40 can be moved to an arbitrary position. Cavitation nozzle 40
Is screwed and fixed to one end of a connection fitting 41, and the other end of the connection fitting 41 is connected to a position adjusting tube 42. The position adjusting pipe 42 is provided with a fixing screw 4 screwed into the flange 29.
It is fixed to the flange 29 by 3.

The position adjusting tube 42 is slidably disposed in an insertion hole 44 formed in the center of the flange 29. Therefore, by loosening the fixing screw 43, the position adjusting tube 4
2 can be moved to fix the cavitation nozzle 40 at an arbitrary position of the cavitation generating section 39. The turbulence generation chamber 37 is used for collapse of cavitation bubbles,
And a space for generating a turbulent flow such as a vortex. The turbulence causes the cavitation generation efficiency to vary depending on the position of the cavitation nozzle 40, so that the position of the cavitation nozzle 40 can be adjusted on site.

[Fifth Embodiment of Liquid Quality Reforming Apparatus] FIG. 26
Shows a fifth embodiment of the liquid quality reforming apparatus, and shows a liquid quality reforming apparatus 60 when applied to seawater reforming of a land-based fish culture apparatus.
It is. The turbulence generating box 61 has a flat rectangular shape similar to that of the first embodiment. A turbulence generation chamber 62 is formed inside the turbulence generation box 61. The turbulence generating box 61 has the above-described shape, but the inside thereof has a curved portion 6 in order to generate cavitation and smoothen the vortex flow.
3 is formed.

The end of the turbulence generating box 61 has a flange 64
Are fixed by bolts 65. One surface of the turbulence generating box 61 is covered with a cover member (not shown) as in the first embodiment. A jet nozzle 66 for jetting pressurized seawater is fixed to the flange 64. In the turbulent flow generation box 61 in the injection direction of the injection nozzle 66, a cavitation generation section 67 having a cylindrical space in cross section is formed.

In the turbulence generating box 61 on the opposite side where the injection nozzle 66 is disposed, a discharge port 68 communicating with the turbulence generating chamber 62 is formed. The discharge nozzle 68 is provided at the discharge port 68.
One end of 9 is screwed and fixedly arranged. One end of a connecting member 70 is fixed to the other end of the discharge nozzle 69.
One end of an air pipe 71 is screwed into the connector 70 in a direction perpendicular to the direction in which seawater is discharged from the discharge nozzle 69.

The air pipe 71 is for drawing air in by the negative pressure of seawater discharged from the discharge nozzle 69. A pipe joint 72 is screwed into the other end of the connecting tool 70. Therefore, seawater containing air is discharged from the end of the pipe joint 72. With the above structure, the liquid quality reforming device 60 has the following functions. The seawater injected from the injection nozzle 66 undergoes cavitation in the cavitation generation section 67 and enters the turbulence generation chamber 62.

The seawater entering the turbulence generating chamber 62 generates turbulence such as cavitation bubbles and eddy currents in the same manner as described above. By the cavitation action, ammonia, nitrogen nitrate, carbon dioxide, chlorine, oxygen, etc. in seawater are degassed. Furthermore, it destroys, sterilizes, and kills fish parasites, parasite eggs, larvae, and Escherichia coli in seawater. The seawater subjected to the cavitation treatment is discharged from the discharge nozzle 69, and the air in the atmosphere is sucked from the air pipe 71 by the negative pressure due to the discharge and mixed with the seawater.

The cavitation-treated seawater mixed with air is discharged from the pipe joint 72 to a seawater tank (not shown). At this time, the fine bubbles that have been degassed by the cavitation process and are discharged are released into the air together with a large amount of air sucked from the air pipe 71. For this purpose, the above-mentioned seawater is degassed for ammonia, nitrogen nitrate, carbon dioxide, chlorine, oxygen and the like. However, since a large amount of air is sucked in at the same time, the amount of dissolved oxygen useful for fish cultivation is balanced and does not decrease.

Further, there is also an effect of slightly cooling seawater that has risen due to the incorporation of air. By mixing this air with seawater, gas harmful to fish degassed in the turbulence generation chamber 62 can be effectively released to the atmosphere. as a result,
The PH value of seawater was also close to that of natural seawater (8.3). Table 1 below shows representative examples of these data.

[0084]

[Table 1]

According to the liquid quality reforming apparatus and the reforming method of the present invention, degassing,
Mixing, stirring, sterilization, insecticide, decomposition, emulsification, etc. can be effectively performed. Further, the present invention can be formed only by a container and a cavitation nozzle which form a simple closed space, and the cost is extremely low.

[Brief description of the drawings]

FIG. 1 is a plan sectional view showing an embodiment of a liquid quality reforming apparatus of the present invention.

FIG. 2 is a front sectional view of FIG. 1;

FIG. 3 is a plan view abstracted and traced from a high-speed photograph of a vortex at a certain moment.

FIG. 4 is a plan view abstracted and traced from a high-speed photograph of the eddy current one second after the moment in FIG. 3;

FIG. 5 is a sectional view showing a coordinate system for jet flow analysis.

FIG. 6 is a cross-sectional view showing a coordinate system for jet analysis of a restricted jet model.

FIG. 7 is a graph showing a relationship between a nozzle opening shape and a cavitation initiation coefficient.

FIG. 8 is a graph showing a relationship between a rapidly expanding nozzle and a cavitation initiation coefficient.

FIG. 9 is a graph showing the relationship between cavitation erosion and jet core length.

FIG. 10 is a graph showing a relationship between a cavitation ultrasonic maximum value position and a jet core length.

FIG. 11 is a cross-sectional view illustrating an example of a nozzle shape.

FIG. 12 is a sectional view showing another example of the nozzle shape.

FIG. 13 is a sectional view showing still another example of the nozzle shape.

FIG. 14 is a sectional view showing still another example of the nozzle shape.

FIG. 15 is a graph showing the relationship between the diameter of a nucleus and the number thereof.

FIG. 16 is a graph showing the relationship between the air content and the initial cavitation coefficient.

FIG. 17 is a graph showing the occurrence and disappearance of cavitation.

FIG. 18 is a cross-sectional view showing a known nozzle for generating a stationary jet.

FIG. 19 is a cross-sectional view showing a known nozzle for generating an unsteady jet.

FIG. 20 is a cross-sectional view showing another known nozzle for generating an unsteady jet.

FIG. 21 is a plan view showing one dynamic of the eddy current.

FIG. 22 is a plan view showing another dynamic state of the eddy current.

FIG. 23 shows a second embodiment of the liquid quality reforming apparatus, and is an example in which the internal space of the turbulence generating unit is cylindrical.

FIG. 24 shows a third embodiment of the liquid quality reforming apparatus, and is an example in which the shape of the nozzle of the second embodiment of the liquid quality reforming apparatus is changed.

FIG. 25 shows a fourth embodiment of the liquid quality reforming apparatus, and is an example in which the shape of the nozzle of the third embodiment of the liquid quality reforming apparatus is changed.

FIG. 26 shows a liquid quality reforming apparatus according to a fifth embodiment of the present invention, which is applied to seawater reforming of a land-based fish culture apparatus.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Liquid reformer 2 ... Turbulence generation box 3 ... Double nozzle 5 ... Cavitation generation part 6 ... Gas-liquid introduction part 7 ... Liquid introduction part 8 ... Gas introduction part 14 ... Jet hole 15 ... Axial liquid introduction hole CL ... Longitudinal center lines 62,37 ... Turbulence generation chamber 40 ... Cavitation nozzle 67 ... Cavitation generation part 69 ... Discharge nozzle 71 ... Air tube

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 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Teruo Masumoto 1534 Hara, Karatsu-shi, Saga Prefecture, Japan W72M Co., Ltd. 1534 Hara, Karatsu-shi, Saga Prefecture

Claims (14)

[Claims] Cavitation generating means for generating cavitation by injecting a pressurized liquid, wherein the liquid jetted from the cavitation generating means is formed as a jet stream, and the jet stream is transformed into a dynamic vortex. A liquid quality reforming apparatus comprising: a turbulence generating means having a substantially closed space; and a discharge port for discharging the liquid from the turbulence generating means. 2. A liquid quality reforming apparatus according to claim 1, wherein said cavitation generating means is formed as a nozzle for injecting only said liquid. 3. The liquid quality reforming apparatus according to claim 1, wherein the dynamic vortex is a vortex, and a central region of the vortex moves in the turbulence generating means. 4. The liquid quality reforming device according to claim 3, wherein the movement is a periodic movement in the space. 5. The turbulent flow generating means according to claim 4, wherein the turbulence generating means is flat in a three-dimensional space, a general height of the space is represented by H, and a general width thereof is represented by W, When the effective diameter of the opening is represented by D1, the jet stream is emitted in the direction of the approximate center line of the space in the longitudinal direction, and the vortex generation conditions are D1 <H and W / H>. 4. A liquid quality reforming device, which is characterized in that: 6. The nozzle according to claim 5, wherein the nozzle comprises a downstream flow path and an upstream flow path, and the effective diameter of the downstream flow path is represented by D1 and the effective diameter of the upstream flow path is represented by D2. When the effective length of the downstream flow path is represented by L, the condition for generating the vortex is L / D2 ≧ 5 and D1 / D2 ≧ 2. 7. The nozzle according to claim 6, wherein the nozzle comprises a downstream flow path and an upstream flow path, and the effective diameter of the downstream flow path is represented by D1 and the effective diameter of the upstream flow path is represented by D2. When the effective length of the downstream flow path is represented by L, the vortex generation condition is L / D2 ≧ 8 and 4 ≧ D1 / D2 ≧ 3. 8. The space according to claim 7, wherein the space is flat, the nozzle includes a downstream flow passage and an upstream flow passage, and the approximate height of the space is H, and the approximate width of the space is H. W, the effective diameter of the downstream flow path is represented by D1, the effective diameter of the upstream flow path is represented by D2, and the jet flow is directed in the longitudinal direction and in the direction of the approximate center line of the space. The condition for generating the eddy current is D1 <H and W / H> 4, and the condition for generating the eddy current is L / D2 ≧ 5 and D1 / D2 ≧ 2. Liquid quality reformer. 9. The liquid quality reforming apparatus according to claim 1, wherein the liquid quality reforming apparatus is used for destroying biological cells in the liquid. 10. A liquid quality reforming apparatus according to claim 1, wherein the liquid quality reforming apparatus is used for degassing a dissolved gas in the liquid. 11. The gas suction pipe according to claim 1, wherein a discharge nozzle is disposed at the discharge port, and a gas is sucked into the discharge nozzle by a negative pressure due to discharge of the liquid. A liquid quality reforming device, characterized in that: 12. The liquid quality reforming apparatus according to claim 11, wherein the gas suction pipe is for sucking air. 13. A jet stream formed by jetting a liquid pressurized by a nozzle into a space defined by a fixed volume to generate cavitation and generate a vortex in the jet stream. A liquid quality reforming method including generating a vortex in the vortex; and moving a central region of the vortex. 14. The liquid quality reforming method according to claim 13, wherein the movement is a periodic movement in the space.