JP7475579B2 - Microproduct Generator - Google Patents

Description

The present invention relates to a fine product generating device.

When microscopic bubbles are generated in liquids, including water, they reach several thousand degrees and several thousand atmospheric pressures when they disappear, forcing the gas molecules inside to break down. This ultimately generates free radicals with strong oxidizing power. These free radicals have strong bactericidal power, so liquids containing microscopic bubbles, such as water, are used to sterilize food ingredients.

Surface tension has a large effect on the disappearance of microscopic bubbles. Due to this surface tension, microscopic bubbles in a liquid cannot maintain a stable state for long periods of time. This is because, due to surface tension, the smaller the microscopic bubbles become, the faster they disappear.

In recent years, it has been discovered that ions contribute to extending the lifespan of such fine bubbles, more specifically microbubbles or nanobubbles. Nanobubbles are bubbles with a diameter of, for example, less than 1 μm, and microbubbles are bubbles with a diameter of, for example, less than 50 μm. The diameter of stabilized nanobubbles varies depending on the type of electrolyte and ion concentration, but is approximately 50 to 500 nm.

Ions gather around the microscopic bubbles, and in the case of nanobubbles, they exert a strong electrostatic repulsive force. This electrostatic repulsive force is balanced with the shrinking force caused by surface tension, resulting in stabilization. This stabilization allows the microscopic bubbles to be taken into the bodies of living foodstuffs such as shellfish, eliminating bacteria within the body. In addition to being used as foodstuffs, it is expected that microscopic bubbles will also be used in a wide range of fields, such as environmental purification, medicine, and health.

The electrolysis of water can be used to generate microscopic bubbles. Conventionally, microscopic bubbles have been generated in flowing water by pressurizing and dissolving bubbles generated by electrolysis of water in the flowing water and then reducing the pressure. Electrodes are disposed in a spiral flow space, and the flowing water flows between the electrodes in the flow space, thereby facilitating the detachment (peeling) of bubbles generated on the electrode surface and mixing them into the flowing water as microscopic bubbles (see, for example, Patent Document 1).
In generating such fine bubbles, it is important to more efficiently separate the bubbles generated on the electrode surface at the fine bubble level.

JP 2007-75674 A

Therefore, the present invention proposes a fine product generating device that can more efficiently separate bubbles generated on the electrode surface at the level of fine bubbles.

A micro-bubble generator according to one aspect of the present disclosure includes a first electrode in contact with the liquid to be electrolyzed, and a second electrode disposed on an inner peripheral surface of a structure facing the first electrode and having a curved portion that changes the flow direction of the liquid to be electrolyzed into a swirling flow , the second electrode being in contact with the liquid, the cross-sectional structure of the second electrode having a triangular protrusion having a tip at which the electrical resistance between the second electrode and the first electrode is minimized, and the second electrode has a protrusion that generates unevenness in which the distance from the first electrode in the radial direction changes depending on the position in the circumferential direction of the structure, and the liquid flows through the first electrode. The nozzle has a first surface located upstream and a second surface located downstream with respect to the direction of the swirling flow generated, and on the first surface, the electrical resistance between the first electrode and the tip of the convex portion gradually decreases, so that most of the bubbles generated from the first surface of the second electrode are reliably detached at an early stage and nano-level fine bubbles are efficiently generated, and on the second surface, nano-level fine bubbles are efficiently generated from the second surface of the second electrode by boundary layer separation, and nano-level fine bubbles are generated from the second electrode by the electrolysis.

The present invention makes it possible to more efficiently remove bubbles that occur on the electrode surface at the microbubble level.

1A to 1C are diagrams illustrating an example of application of a micro-bubble generating device according to an embodiment of the present invention. FIG. 1 is a diagram illustrating an example of the configuration of a micro-bubble generating device according to an embodiment of the present invention. FIG. 2 is a cross-sectional view of an example of a structure constituting a fine-bubble generating device according to one embodiment of the present invention. FIG. 4 is an enlarged view of part A shown in FIG. 3. 11A to 11C are diagrams illustrating examples of shapes of convex portions. 1A to 1C are diagrams illustrating examples of flow path forming members for forming a spiral flow of circulating water. 10A to 10C are diagrams illustrating another application example of the micro-bubble generating device according to one embodiment of the present invention.

Below, the form for carrying out the present invention will be described with reference to the drawings. Note that the embodiment described below, including modified examples, is merely an example, and the technical scope of the present invention is not limited to this. The technical scope of the present invention also includes various modified examples.

FIG. 1 is a diagram for explaining an application example of a fine product generating device according to an embodiment of the present invention, and a fine air bubble generating device will be explained as the fine product.
The application example shown in Fig. 1 is an example in which a fine bubble generator 3 is used for water treatment in a water facility 1. The fine bubble generator 3 is combined with a metal ion generator 2 and the like and used as a cation-containing fine bubble generator. This cation-containing fine bubble generator generates multiple types of optional cations and fine bubbles in water supplied as liquid from the water facility 1. In other words, water containing multiple types of optional cations and fine bubbles is generated. As a result, the water facility 1 supplies water, which is a liquid useful in fields such as environmental purification, food, medicine, and health.

The water facility 1 is, for example, a water supply facility, a water purification facility, or a facility for producing treated water. In water supply facilities, water is used, for example, to sterilize water and supply minerals. This provides benefits to people who drink tap water, such as blood purification, improved resistance, and health promotion through the supply of minerals. Tap water also has advantages in that it has a higher cleaning power and stronger bactericidal power. This advantage allows the cation-containing microbubble generator to be used in water purification facilities. One advantage is that it can create an environment that is more favorable for plant growth. For these reasons, the microbubble generator 3 may be used to realize a cation-containing microbubble generator in a production facility aimed at producing treated water.

The cation-containing microbubble generator includes a metal ion generator 2, a microbubble generator 3, and a vortex pump 4.
The metal ion generator 2 is capable of generating, for example, multiple types of metal ions as cations in the flowing water from the water facility 1. The generation of cations is performed by passing a current between a positive electrode and a negative electrode. The type of cation to be generated can be selected by adopting a positive electrode material for the positive electrode.

The microbubble generator 3 generates microbubbles by electrolysis of water in the flowing water containing the multiple types of cations generated by the metal ion generator 2. The microbubbles referred to here are microbubbles or nanobubbles.

The vortex pump 4 pressurizes the water containing the micro-bubbles generated by the micro-bubble generator 3 and sends it to the water facility 1. The vortex pump 4 then circulates the water stored in the water facility 1 back to the water facility 1 via the metal ion generator 2, the micro-bubble generator 3, and its own vortex pump 4. For this reason, the water that flows out of the water facility 1 for treatment is hereafter also referred to as "circulating water" to distinguish it from the water within the water facility 1.

The vortex pump 4 allows both the metal ion generator 2 and the micro-bubble generator 3 to generate cations and micro-bubbles in the flowing circulating water. The reason for using flowing circulating water is to prevent or suppress the cations generated at the positive electrode from moving to the negative electrode and disappearing. For the micro-bubbles, the reason is to cause the bubbles generated on the electrode surface to peel off at the micro-bubble level by the circulating water. For this reason, in an environment where water does not flow, the vortex pump 4 is an essential component of the micro-bubble generator. In an environment where water flows naturally or is flowed for other purposes, the vortex pump 4 is not an essential component.

Fig. 2 is a diagram for explaining a configuration example of a fine-bubble generating device according to one embodiment of the present invention, and Fig. 3 is a cross-sectional view of an example of a structure constituting the fine-bubble generating device according to one embodiment of the present invention.
As shown in Fig. 2, the micro-bubble generating device 3 is provided with a cylindrical structure 20 for causing circulating water to flow as a swirling flow. Thus, the micro-bubble generating device 3 causes circulating water to flow through the structure 20, electrolyzes the circulating water flowing through the structure 20, and generates micro-bubbles. The cross-sectional view of Fig. 3 shows the structure 20 cut along a plane perpendicular to the axial direction of the structure 20.

2 and 3, the structure 20 includes a cylindrical negative electrode (first electrode) 21 arranged along the axial direction at a position including the axis. In this embodiment, the entire structure 20 is the positive electrode (second electrode) 22. The reason why the positive electrode 22 (structure 20) is cylindrical and the negative electrode 21 is cylindrical is to basically make the distance between the positive electrode 22 and the negative electrode 21 in the radial direction of the positive electrode 22 the same regardless of the circumferential position of the positive electrode 22. This is to prevent the way bubbles are generated from differing depending on the circumferential position of the positive electrode 22. Hereinafter, the circumferential direction, radial direction, and axial direction are used to refer to the structure 20 unless otherwise specified.

At one end of the structure 20, which is the lower part, a water inlet 23 is provided for allowing the circulating water to flow into the inside, and at the other end of the structure 20, which is the upper part, a discharge port 24 is provided for discharging the circulating water that has flowed into the inside. The water inlet 23 is adapted to adjust the direction of the circulating water flowing into the structure 20 so that the circulating water that has flowed into the structure 20 flows upward as a swirling flow (spiral flow). As a result, the circulating water that has flowed into the structure 20 from the water inlet 23 flows out of the discharge port 24 as a spiral flow that flows upward around the negative electrode 21 and along the inner surface of the structure 20, as shown by the arrow in FIG. 2.

The microbubble generator 3 includes a power supply unit 10 for supplying current to the negative electrode 21 and the positive electrode 22. The power supply unit 10 includes a DC power supply 11. The negative terminal of the DC power supply 11 is connected to earth and also to the negative connection terminal 15. Between the positive terminal of the DC power supply 11 and the positive connection terminal 14, a variable resistor 12 and an ammeter 13 are connected in series from the positive terminal side. Thus, the variable resistor 12 is for adjusting the amount of current supplied from the power supply unit 10, and the ammeter 13 is for checking the amount of current.

The positive connection terminal 14 and the positive electrode 22, and the negative connection terminal 15 and the negative electrode 21 are connected by wiring. When a current is supplied, hydrogen bubbles are generated on the surface of the negative electrode 21, and oxygen bubbles are generated on the surface of the positive electrode 22.

FIG. 4 is an enlarged view of part A shown in FIG.
4, on the side of the positive electrode 22 facing the negative electrode 21, protrusions 22a are formed in a line, which generate unevenness in which the distance from the negative electrode 21 in the radial direction changes depending on the circumferential position. 22at denotes the tip of the protrusion 22a.

The distance between the protrusion 22a and the negative electrode 21 is the shortest at the tip 22at. In other words, the electrical resistance between the negative electrode 21 and the tip 22at is the smallest. Therefore, most of the bubbles are generated at the tip 22a and its vicinity. The protrusion 22a also turbulently flows the circulating water near the surface of the positive electrode 22. This turbulence acts to make the flow of the circulating water faster near the surface of the positive electrode 22. The spiral flow of the circulating water causes the circulating water to flow as shown by the arrows in FIG. 4. Therefore, the circulating water generates a fast flow toward the surface of the positive electrode 22. As a result, most of the bubbles generated on the surface of the positive electrode 22 can be peeled off at an earlier stage and more reliably. As a result, nano-level fine bubbles are generated more efficiently.

Fig. 5 is a diagram for explaining examples of the shape of the convex portion. Here, examples of the shape of the convex portion 22a and the effect of the shape will be specifically explained with reference to Fig. 5.
The shape of the protrusion 22a shown in Fig. 5 is a cross-sectional shape when cut along a plane perpendicular to the axial direction, similar to Fig. 4. The arrows in Fig. 5 indicate the direction of inertia acting on the circulating water on that plane due to the spiral flow of the circulating water.

The convex portion 22a has an overall triangular shape, and has a first surface 22aa located on the upstream side in the direction of the circulating water flow, and a second surface 22ab located on the downstream side. The thick line area of the two surfaces 22aa, 22ab indicates the range in which air bubbles can be efficiently separated by the circulating water.

On the first surface 22aa, the direction of the circulating water flow allows most of the air bubbles to be efficiently and reliably separated. On the other hand, the angle that the second surface 22ab makes with the radial direction is closer to a right angle than the first surface 22aa. Therefore, the angle that the second surface 22ab makes with the direction of the circulating water flow is relatively close. Due to this and the turbulence of the circulating water, the separation point where the circulating water flowing from the tip 22at along the second surface 22ab separates from the second surface 22ab (boundary layer separation) occurs behind the tip 22at. As a result, the air bubbles generated in the part indicated by the thick line can be efficiently and reliably separated even on the second surface 22ab.

As described above, most of the bubbles are generated at and near the tip 22at. The region where most of the bubbles are generated is included within the bold line portion shown in FIG. 5. Therefore, most of the bubbles generated on the surface of the positive electrode 22 can be reliably separated into fine bubbles. This is why the positive electrode 22 is fabricated as a structure 20. In other words, a larger amount of gas is generated on the positive electrode 22 side than on the negative electrode 21 side, which is advantageous for generating fine bubbles.

Note that the cross-sectional shape of the convex portion 22a is a shape represented by a straight line, but it does not have to be such a shape. The overall shape is not limited to a triangle either. It may be a polygon with four or more sides.

The negative electrode 21 and the positive electrode 22 may both be planar and arranged parallel to each other. In this case, it is desirable to form projections and recesses such as the projections 22a on the negative electrode 21.

In this embodiment, the positive electrode 22 (structure 20) on which the protrusion 22a is formed is cylindrical in shape. This is to increase the length of the virtual flow path through which the circulating water flows while increasing the area of the positive electrode 22 surface. This makes it easier to increase the flow rate of the circulating water per unit area of the positive electrode 22 surface. This is therefore effective in removing air bubbles that occur on the surface of the positive electrode 22 more reliably at an earlier stage.

By aligning the axis of the negative electrode 21 and making it cylindrical and arranging it along the axial direction of the structure 20, the entire surface of the positive electrode 22 can be used to generate bubbles. This is also effective. The positive electrode 22 may be fabricated as a separate part from the structure 20. In that case, it may be fabricated as multiple parts.

The inertia of the circulating water can be utilized by changing the direction in which the circulating water flows. For this reason, the structure 20 does not have to be one that causes the circulating water to flow in a spiral flow. As a result, the structure 20 does not have to be cylindrical in shape. In other words, the structure 20 can be one that has curved portions, such as a bent tube or an object with a sector-shaped portion. However, it is necessary that the majority of the air bubbles are generated at the tip 22at of the convex portion 22a and in its vicinity.

In addition, in this embodiment, the circulating water is made to flow in a spiral direction within the structure 20 by adjusting the angle at which the circulating water flows into the structure 20, but a flow path for making the water flow in a spiral direction may be formed within the structure 20. Such a flow path may be formed, for example, by disposing a flow path forming member 25 as shown in FIG. 6 within the structure 20.

When a cation-containing microbubble generator 3 is used to realize the cation-containing microbubble generator, the positional relationship of the constituent metal ion generator 2, microbubble generator 3, and vortex pump 4 is not limited to that shown in FIG. 1. As long as the flow of circulating water, which is a liquid (running water), can be ensured, the positional relationship between them can be modified in various ways. For this reason, for example, as shown in FIG. 7, the circulating water from the water facility 1 may be circulated back to the water facility 1 via the microbubble generator 3, vortex pump 4, and metal ion generator 2.

In addition, in this embodiment, the generation of fine bubbles has been described as a fine product, but it may be a product such as ions generated from the electrode by electrolysis. In addition, the uneven portion formed on the electrode may be configured by providing a large number of fine cylindrical protrusions on the electrode.

REFERENCE SIGNS LIST 1 Water facility 2 Metal ion generator 3 Micro-bubble generator 4 Vortex pump 10 Power supply unit 11 DC power supply 12 Variable resistor 13 Ammeter 14 Positive connection terminal 15 Negative connection terminal 20 Structure 21 Negative electrode 22 Positive electrode 23 Water intake 24 Discharge port

Claims (3)

In the electrolysis of liquids,
a first electrode in contact with the liquid to be electrolyzed;
a second electrode disposed on an inner circumferential surface of a structure having a curved portion that changes the flow direction of the liquid to be electrolyzed into a swirling flow , the second electrode facing the first electrode and in contact with the liquid;
a cross-sectional structure of the second electrode having a triangular protrusion with a tip end at which electrical resistance between the second electrode and the first electrode is minimum, and having a protrusion that generates unevenness in which the distance from the first electrode in a radial direction varies depending on the position in the circumferential direction of the structure, the second electrode having a first surface located on the upstream side and a second surface located on the downstream side with respect to the direction of the swirling flow in which the liquid flows,
On the first surface, the electrical resistance between the first electrode and the tip of the convex portion gradually decreases, and most of the bubbles generated from the first surface of the second electrode are reliably detached at an early stage, thereby efficiently generating fine bubbles at a nano level;
On the second surface, nano-level fine bubbles are efficiently generated from the second surface of the second electrode by boundary layer separation;
A fine product generating device that generates nano-level fine bubbles from the second electrode by the electrolysis. The structure has a cylindrical shape that changes the flow direction of the liquid and causes the liquid to flow as a swirling flow.
The fine product generating apparatus according to claim 1 . the first electrode has a cylindrical shape and is disposed along the axial direction of the structure at a position including the axis of the structure,
the protrusion formed on the second electrode changes a distance between the second electrode and the first electrode depending on a position in a circumferential direction of the structure;
The fine product generating apparatus according to claim 2 .

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