JP7164846B1 - Fine bubble generation method - Google Patents

Abstract

Kind Code: A1 The present invention relates to a method for generating fine bubbles of nano-level or micro-level. SOLUTION: A microbubble-containing water containing microbubbles generated by a microbubble generation unit that generates microbubbles by forming unevenness of a predetermined shape on the surface and the microbubble-containing water generated by the microbubble generation device is measured. The size and number of microbubbles contained in water are measured, and the shape of the irregularities on the surface to be formed on the microbubble generating device is set based on the size and number of the microbubbles, which are the measurement results. It can be achieved by providing a microbubble generation method. [Selection diagram] Fig. 1

Description

TECHNICAL FIELD The present invention relates to a method for generating fine bubbles of nano-level or micro-level.

Today, research on nano-level and micro-level microbubbles is progressing rapidly with respect to their physical properties, generation mechanisms, specific uses, and their practical application. For example, research on purification and sterilization of polluted water, cultivation of aquatic organisms using microbubble-containing water containing nano-order microbubbles, and improvement of water quality by supplying water containing microbubbles to paddy fields. research is being done.

Conventionally, many methods have been proposed as methods for generating such microbubbles, such as a pressurized dissolution method, an orifice or venturi tube method, use of ultrasonic vibration, use of a microporous filter, and the like. For example, Patent Literature 1 discloses a method for generating microbubbles using a venturi tube system.

In this method of generating microbubbles, inflowing water or contaminated water is stored at one end, supplied to a venturi tube through a flow path, and passed through the venturi tube at high speed to generate a negative pressure state, and the water or contaminated water is It is an invention that utilizes the fact that supersaturated air dissolved in the liquid is separated and becomes fine bubbles. For this reason, a Venturi tube with a small diameter is used, and by increasing the velocity inside the Venturi tube, a high vacuum is generated and microbubbles are generated.

Japanese Unexamined Patent Application Publication No. 2011-115771

However, in the conventional microbubble generation method, it is difficult to freely set the size of microbubbles to be generated. For example, it has been difficult to generate microbubbles of appropriate size and quantity according to the application. Moreover, it has been more difficult to simultaneously generate microbubbles of a plurality of sizes with one microbubble generator.
Accordingly, the present invention provides a method for generating nano-level or micro-level microbubbles capable of generating microbubbles of a desired size according to the application and simultaneously generating microbubbles of a plurality of sizes. .

According to the present invention, the above problem is solved by a microbubble generating device for generating microbubbles by forming unevenness in a predetermined shape on the surface, and measuring water containing microbubbles containing microbubbles generated by the microbubble generating device. and a microbubble measuring device for measuring the size and number of microbubbles contained in the microbubble-containing water, and based on the size and number of microbubbles, which are the measurement results of the microbubble measuring device, the microbubbles This can be achieved by providing a method for generating microbubbles, characterized by setting the shape of unevenness on the surface formed on the generating device.

Further, a high-speed swirling flow generated by adding a swirling flow generating device to the microbubble generating device can be supplied.

Further, the shape of the microbubble generating device having the unevenness of the predetermined shape is not limited, and various shapes such as plate-like, cylindrical, spherical, and rod-like are possible. Furthermore, it may be a container such as a cup, or a semi-cylindrical shape such as a semicircle, U-shape, or V-shape.
For example, in the case of a tubular member, it may be a circular tubular member or a rectangular tubular member such as square, hexagonal, octagonal, etc., and the diameter of the tubular member and the depth of the irregularities formed on the tubular member may be appropriately selected. is set to set the size of microbubbles contained in the microbubble-containing water.

It is a figure explaining the micro-bubbles generation method of this embodiment. It is a figure explaining the data of the size of microbubbles produced|generated by the microbubble production|generation apparatus of this embodiment, and a quantity. It is a figure explaining other data of the size of the micro-bubbles produced|generated by the micro-bubble production|generation apparatus of this embodiment, and a quantity. It is a figure explaining other data of the size of the micro-bubbles produced|generated by the micro-bubble production|generation apparatus of this embodiment, and a quantity. FIG. 3 is a diagram for explaining data on the size and quantity of microbubbles generated by the microbubble generating device of the present embodiment. is a diagram for explaining an example of simultaneously generating . It is a figure explaining other micro-bubbles generation methods of this embodiment.

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, embodiments of the present invention will be described in detail based on the drawings.
FIG. 1 is a diagram for explaining the method for generating microbubbles according to this embodiment. In the figure, a microbubble generator 1 is a device for generating nano-level microbubbles, and a high-speed swirl flow is supplied to the microbubble generator 1 from a swirl flow generator 2 . Further, the size and number of nano-level microbubbles contained in the water generated by the microbubble generating device 1 are measured by a microbubble measuring device 3 separately prepared.

The swirling flow generating device 2 has a swirling flow generating member such as a blade mounted therein, for example, turns the supplied pressurized water into a swirling flow, and supplies it to the microbubble generating device 1 .

The microbubble generator 1 is composed of, for example, a cylindrical pipe made of metal such as stainless steel, and the inner peripheral surface of the pipe is processed to be uneven. For this unevenness processing, for example, blasting is employed in which an abrasive is struck against the inner peripheral surface of the pipe at high speed to form unevenness.
By this blasting, the inner peripheral surface of the cylindrical pipe is roughened to a predetermined depth.

The microbubble generating device 1 is not limited to a circular pipe, and may be a polygonal pipe such as a square, hexagon, octagon, etc. Furthermore, it is not limited to metal, and may be made of other materials such as resin. You may use a pipe that In addition, a plurality of unevennesses having different depths may be formed on the inner peripheral surface of the pipe. may be
Further, it is not limited to a pipe shape, and may be a plate shape, a concave shape, a laminated shape, a honeycomb shape, or the like, and the surface thereof is processed to have desired unevenness.

On the other hand, the microbubble measuring device 3 irradiates the water containing microbubbles discharged from the microbubble generating device 1 with laser light, and captures the scattered light of the nanoparticles contained in the water containing microbubbles with a camera. For example, an image is taken with a CMOS camera, the scattered light is visualized, the movement of each scattered light is tracked (tracked), and the size and number of microbubbles are measured from the respective moving speeds. That is, the size and number of each nano-level microbubble are measured by the difference in Brownian motion for each particle.

Next, the generation of microbubbles and the measurement of the size of microbubbles in the case of using this embodiment are performed in the following procedure.
First, a liquid (for example, water) pressurized by a pump (not shown) or the like is supplied to the swirling flow generating device 2, and the swirling flow is generated by, for example, vanes provided in the swirling flow generating member in the swirling flow generating device 2. generate. This swirl flow turns into a high-speed swirl flow and is supplied to the fine bubble generator 1 .

The high-speed swirling flow supplied to the microbubble generator 1 flows through the pipe-shaped microbubble generator 1 having unevenness on the inner peripheral surface, and generates, for example, nano-level microbubble-containing water. The microbubble-containing water thus generated differs in size and number of microbubbles depending on conditions such as the diameter of the pipe and the depth of the unevenness formed on the inner peripheral surface of the microbubble generator 1 .

That is, by optimally setting the conditions such as the depth of the unevenness formed on the inner peripheral surface of the microbubble generating device 1, it is possible to generate microbubbles of a desired size. can be obtained.

For example, FIG. 2 shows a microbubble generating device 1 using a metal pipe with a diameter of 25 mm and forming irregularities with a depth of 8.2 μm on the inner peripheral surface by the above blasting (for example, a microbubble generating device under these conditions). 1A) is used to generate microbubbles. A swirl flow generated by the swirl flow generator 2 is supplied to the fine bubble generator 1A.

That is, FIG. 2 is a graph showing the measurement results obtained by taking in the microbubble water generated under the above conditions and using the microbubble measuring device 3 as sample water. In the figure, the horizontal axis indicates the particle diameter (size) of microbubbles contained in the taken-in microbubble water, and the vertical axis indicates the number (quantity) of the particles.

In addition, D90 shown at the bottom of the figure indicates the size of 90% fine bubbles contained in the obtained sample water. Specifically, it indicates that the obtained sample water contains 90% of microbubbles with a diameter of 152 nm or less.

Similarly, D50 indicates that the obtained sample water contains 50% microbubbles with a diameter of 100 nm or less, and D10 indicates that the obtained sample water contains 10% microbubbles with a diameter of 75 nm or less. indicates that the Therefore, for example, if the size of microbubbles to be generated depending on the application is 152 nm or less, the fine bubbles having the above-described unevenness are formed under conditions that allow the generation of microbubble-containing water containing 90% of microbubbles of 152 nm or less in size. The bubble generator 1A is selected.

Next, FIG. 3 is a diagram showing another example of measurement. As sample water, microbubbles are generated by using the microbubble generator 1B in which irregularities with a depth of 26.2 μm are formed on the inner peripheral surface by the above-described blasting. This is a generated example. Also in this case, a swirling flow is supplied.

In the case of this example, a numerical value of 238 was obtained as D90, indicating that 90% of microbubbles with a diameter of 238 nm or less were contained in the obtained sample water. Similarly, in this example, a numerical value of 134 was obtained as D50, indicating that 50% of microbubbles with a diameter of 134 nm or less were contained in the obtained sample water, and a numerical value of 98 was obtained as D10. It indicates that the sample water contains 10% microbubbles with a diameter of 98 nm or less.

Therefore, for example, if the size of the microbubbles to be generated is 238 nm or less depending on the application, the fine bubbles having the above-described unevenness are formed under conditions that allow the generation of water containing microbubbles containing 90% of the microbubbles having a size of 238 nm or less. The bubble generator 1B is selected.

FIG. 4 is a diagram showing still another example of measurement, in which microbubbles were generated as sample water using the microbubble generator 1C in which irregularities with a depth of 36.7 μm were formed on the inner peripheral surface by the blasting process. For example. Also in this case, a swirling flow is supplied.

In this example, a numerical value of 144.4 was obtained as D90, indicating that 90% of microbubbles with a diameter of 144.4 nm or less were contained in the obtained sample water. Similarly in this example, a value of 112.8 was obtained as D50, indicating that 50% of fine bubbles with a diameter of 112.8 nm or less were contained in the obtained sample water, and a value of 95.7 was obtained as D10. is obtained, indicating that the obtained sample water contains 10% microbubbles with a diameter of 95.7 nm or less.

Therefore, for example, if the size of microbubbles to be generated depending on the application is 144.4 nm or less, the unevenness under the conditions that allows the generation of microbubble-containing water containing 90% of microbubbles with a size of 144.7 nm or less. The formed microbubble generator 1C is selected.

Note that the above 90% is an example, and if the desired microbubble size, for example, 80% or more, is sufficient, D80 (size containing 80% of the microbubble size) can be measured and adopted. . It can also be set arbitrarily, such as 85%, 95%, or the like.

On the other hand, the example shown in FIG. 5 is an example in which microbubbles of a plurality of desired sizes are generated by applying a plurality of uneven shapes to the same microbubble generating device 1 . For example, in the example shown in the same figure, microbubbles are generated using a microbubble generating device 1D in which unevenness with a depth of 36.7 μm and unevenness with a depth of 53.6 μm are formed by blasting on the inner peripheral surface. be. Also in this case, a swirling flow is supplied.

In this case, as shown in the figure, there are clear peaks at 128 nm and 251 nm, and microbubble-containing water containing a large amount of microbubbles of this size can be obtained. Therefore, for example, if the size of microbubbles to be generated according to the application is the above two sizes of microbubbles, the microbubble generating device 1D having the unevenness under the above conditions is selected.

In this way, when it is desired to generate microbubbles of a plurality of sizes at the same time, microbubbles of a required size can be simultaneously generated according to the application by performing unevenness processing with a plurality of different depths as described above. It is possible.

In the example shown in FIG. 5, the configuration is such that two different depths of uneven processing are performed. It is also possible to generate fine bubbles of a size corresponding to the application.

In the description of the above embodiment, the swirling flow generated by the swirling flow generating device 2 is supplied to the microbubble generating device 1 (1A to 1D). It is also possible to directly supply constant pressurized water (liquid) such as tap water. Incidentally, FIG. 6 shows the configuration in this case.

In addition, although nano-order microbubbles have been described in the above embodiments, micro-order microbubbles can also be implemented in the same manner.

In the above description, water is used as the liquid used in the microbubble generating device 1. However, the liquid is not limited to water. For example, alcohols such as methanol, ethanol, and propanol; Mineral oil may also be used.

1, 1A to 1D... Fine bubble generator 2... Swirling flow generator 3... Micro bubble measuring device

Claims (4)

A microbubble-containing water containing microbubbles generated by the microbubble generator is measured by using a microbubble generator in which a plurality of unevennesses with a depth of 1 μm to 200 μm are formed on the surface that comes into contact with the pressurized liquid. , measuring the size and number of microbubbles contained in the microbubble-containing water, and setting the uneven shape of the surface to be formed in the microbubble generating device based on the size and number of microbubbles that are the measurement results.death,
A cylindrical member is used as the microbubble generating device having a plurality of unevennesses, and the depth of the unevenness formed on the inner peripheral surface of the tubular member is less than 1% of the diameter of the cylindrical member. A method for generating microbubbles, characterized by: 2. The method for generating microbubbles according to claim 1 , wherein the microbubble generating device is supplied with a high-speed swirling flow generated by a swirling flow generating device. 3. The method for generating microbubbles according to claim 1, wherein the cylindrical member is a circular cylindrical member. 2. The size of the microbubbles contained in the microbubble-containing water is set by appropriately setting the diameter of the cylindrical member and the depth of the unevenness formed on the cylindrical member , or 2. The method for generating microbubbles according to 2.

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