JP5555892B2 - Micro / nano bubble generating method, generating nozzle and generating device - Google Patents

Description

  The present invention relates to a method for generating micro / nano bubbles using water hammer, a generating nozzle, and a generating apparatus.

  The cleaning and sterilization method using micro / nano bubbles is a method that uses only water, air, and a small amount of additives and has a low environmental impact. Therefore, it is an alternative to cleaning and sterilization using conventional detergents and chemicals. Attention has been paid. Moreover, since it is highly safe, application as a sterilization method for vegetables, foods, and the like is also being studied. Three conventional micro / nano bubble generation methods are known: a gas-liquid two-phase flow swirling method, a venturi tube method, and a pressure dissolution method (for example, a gas-liquid two-phase flow swirling method and a pressure dissolution method). (See Patent Documents 1 and 2, respectively).

However, in any generation method, the number of micro / nano bubbles generated is still small and not sufficient. In addition, microbubble water can be easily generated in all three systems, but in order to obtain a sufficient number of micro / nano bubble particles, it is necessary to generate microbubble water by adding a nucleating agent such as a base or magnesium into the microbubble water. is there. The mixing of the nucleating agent has greatly hindered the expansion of application to cleaning and sterilization of semiconductors and foods, but at present, it is very difficult to generate a large amount of micro / nano bubbles using pure water.

In addition, various types of pumps can be used as drive pumps for devices that generate water, air, and a small amount of additives. However, all device components including drive pumps are used for cleaning and sterilization of semiconductors and foods. A device free of metal contamination is also needed. For example, when cleaning semiconductor wafers without metal contamination, the pumps used in the micro / nano bubble generator are made with all the wetted parts not generating any metal ions and the discharge pressure is stable. And 0.3 to 0.6 Mpa is required.

Therefore, as a pump that sends liquid without using rotation in order to avoid a contamination phenomenon that is feared to occur with a pump using rotation, the present inventors have used compressed air in which all parts of the wetted part are made of fluororesin. An apparatus using a driving bellows cylinder pump has been proposed (Patent Documents 3 to 4). In order to achieve the objective of clean cleaning without the influence of contamination, it is desirable to develop technology that uses not only pumps but also all nozzle parts that generate microvalves using fluororesin. Yes.

JP 2009-274045 A JP 2008-264771 A Japanese Patent No. 454751 Japanese Patent No. 4924907

In the prior art, it is extremely difficult to generate a large amount of micro / nano bubbles with pure water alone without using a nucleating agent, and even if a nucleating agent is added, it is required to significantly reduce the amount of addition. It has been. In addition, if the amount of micro / nano bubbles generated can be made larger than that in the prior art, not only can the cleaning and sterilization effect be significantly improved, but it can also be expanded to various uses. Therefore, there is a strong demand for a micro / nano bubble generation method using a new method that replaces the prior art, and a micro / nano bubble generation device that can implement the method.

  Further, in this field, it is conventionally required to construct a system that can generate micro / nano bubbles without contamination. As described above, it is expected that this problem can be solved by applying a compressed air-driven bellows cylinder pump in which all parts of the liquid contact part are made of fluororesin. In addition, if a micro / nano bubble generator using this pump can be used to produce a larger amount of bubbles than in the past, an effective cleaning method for the technological trend of finer wiring in the manufacture of semiconductor devices It is expected to be However, at present, no highly functional device capable of increasing the amount of bubble generation has been obtained in an apparatus composed of a metal-free material.

Therefore, a new method for generating micro-nano bubbles by optimizing the structure and shape of the other components, including pumps, as well as generating nozzles, gas-liquid mixing tanks, liquid delivery equipment, etc. In addition, there is a strong demand for the development of highly functional micro / nano bubble generators. Finally, it is necessary to construct a system that can generate micro / nano bubbles without contamination.

In view of the background as described above, the present invention not only performs clean cleaning and sterilization by generating a large amount of micro / nano bubbles with pure water alone, but also constructs a system capable of generating micro / nano bubbles without contamination. Another object of the present invention is to provide a novel water hammer type micro / nano bubble generation method different from the prior art, a micro / nano bubble generation device including a generation nozzle and a self-adjusting gas-liquid mixing tank.

The basic idea for solving the above problem is to use intense water hammer caused by collision of incompressible water in order to make a large number of micro-nano bubbles containing dissolved gas. In order to realize this, in the generation method and generation device of micro / nano bubbles, the structure and shape of the generation nozzle are optimized so as to maximize the water hammer force, and the generation of a large number of micro / nano bubbles is promoted. The present invention has been achieved by constructing a generator having such a configuration.

That is, the configuration of the present invention is as follows.
[1] The present invention is a method for generating micro / nano bubbles using water hammer force, in which a dissolved liquid in a gas-liquid mixed state is used in a cylinder having two or more through small holes in the circumferential direction. Injecting from the respective openings of the two or more through small holes arranged so as to face each other on the same plane parallel to the radial cross section of the cylinder when jetting from the outside through the through small holes at a pressure higher than atmospheric pressure A micro-nano bubble generation method is provided, wherein micro-nano bubbles are generated by colliding the dissolved solution so that water hammer concentrates on the center of the cylinder.
[2] The present invention includes a gas / liquid suction step, a gas / liquid pressurization step, a dissolved gas enrichment step in which a liquid containing the pressurized gas is mixed with a new gas, and the dissolved gas enrichment. A dissolved gas refinement step of injecting a dissolved liquid in a gas-liquid mixed state adjusted in the gasification step from the outside of the cylinder having two or more through-holes in the circumferential direction through the through-holes at a pressure higher than atmospheric pressure. Yes, and water hammer dissolved solution injected from the cylinder radial cross-section and each opening being positioned to face the two or more through-eyelet on a same plane parallel to the center of the tube is concentrated The method for generating micro / nano bubbles according to claim 1, further comprising generating micro / nano bubbles by colliding with each other.
[3] In the present invention, the pressure above the atmospheric pressure when jetting is 0.2 to 0.6 MPa, and the through small hole has a hole diameter of 0.1 to 6.0 mm leading to the hollow of the cylinder. There is provided the method for generating micro-nano bubbles according to [1] or [2], which is characterized in that it exists.
[4] The present invention is characterized in that the dissolved liquid is an aqueous solution having at least one of the group consisting of ozone, oxygen, hydrogen peroxide, chloric acid, perchloric acid and potassium permanganate. A method for generating micro / nano bubbles according to any one of [1] to [3] is provided.
[5] The present invention provides the generation of micro / nano bubbles according to any one of [1] to [3], wherein the dissolved liquid is an aqueous solution containing carbon dioxide gas, hydrogen gas, or nitrogen gas. Provide a method.
[6] The present invention is a generating nozzle used for generating micro / nano bubbles using water hammer force, each of a hollow cylinder and two or more through small holes in the circumferential direction of the cylinder. The two or more through small holes arranged so that the portions face each other on the same plane parallel to the radial cross section of the cylinder, and the micro / nano bubble discharge port at at least one end of the cylinder, the through small hole Provides a nozzle for generating micro / nano bubbles, characterized in that all of the extended lines passing through the center of the cross-section of the through hole intersect at the center of the cylinder .
[7] The present invention provides the nozzle for generating micro / nano bubbles according to [6], wherein the nozzle has two or more hollow cylinders.
[8] The present invention is characterized in that two or more of the hollow cylinders are arranged in parallel or perpendicular to the inflow or discharge direction of the dissolved liquid. A nanobubble generating nozzle is provided.
[9] The invention according to any one of [6] to [8], wherein in the hollow cylinder, the two or more through small holes are provided in two or more stages in the longitudinal direction of the cylinder. A micro-nano bubble generating nozzle as described is provided.
[10] The invention according to any one of [6] to [9], wherein the through hole has a hole diameter of 0.1 to 6.0 mm at a portion communicating with the cavity of the cylinder. A nozzle for generating micro / nano bubbles is provided.
[11] In the hollow cylinder, the present invention may be configured such that the diameter of the micro / nano bubble discharge port provided in at least one end of the cylinder is the same as the diameter of the cylinder in the portion where the through small holes are arranged in the circumferential direction. Alternatively, the nozzle for generating micro / nano bubbles according to any one of [6] to [10], wherein the nozzle is larger than a diameter of the cylinder.
[12] The present invention mixes a means for sucking a gas and a liquid, a means for simultaneously pressurizing and transporting the gas and the liquid, and the liquid containing the transported gas with a new gas. In order to generate micro-nano bubbles using a gas-liquid mixing tank for enriching dissolved gas by the gas and a dissolved liquid in a gas-liquid mixing state in the gas-liquid mixing tank, the above-mentioned [6] to [11] There is provided a micro / nano bubble generating device comprising a micro / nano bubble generating means having any of the generating nozzles.
[13] The invention according to [12], wherein in the micro / nano bubble generating means, the dissolved liquid is injected at a pressure of 0.2 to 0.6 MPa through a through hole of the generating nozzle. An apparatus for generating micro / nano bubbles is provided.
[14] In the present invention, the gas-liquid mixing tank has the micro / nano bubble generating nozzle, and the liquid containing the gas transported by the pressurizing and transporting means is converted into the gas-liquid by the generating nozzle. The apparatus for generating micro / nano bubbles according to [12] or [13], wherein the apparatus is discharged into a mixing tank.
[15] In the present invention, the gas-liquid mixing tank releases extra gas in the gas-liquid mixing tank so that the amount of liquid and gas and the pressure in the gas-liquid mixing tank are always kept within a certain range. The micro / nano bubble generating device according to any one of [12] to [14], wherein a float valve is provided inside or outside the gas-liquid mixing tank.
[16] According to the present invention, in the micro / nano bubble generator according to any one of [12] to [15], at least one of a pump and a pipe through which the gas-liquid mixed solution passes is made of plastic. An apparatus for generating micro / nano bubbles is provided.
[17] The present invention provides the micro / nano bubble generating device according to [16], wherein at least one of a pump and a pipe through which the gas-liquid mixed solution passes is made of a fluororesin. .
[18] In the present invention, the means for pressurizing and transporting the liquid containing the gas is a device using a compressed air activated or electric bellows cylinder pump. [17] A micro-nano bubble generator according to any one of [17].
[19] The present invention is characterized in that the dissolved liquid is an aqueous solution having at least one of the group consisting of ozone, oxygen, hydrogen peroxide, chloric acid, perchloric acid and potassium permanganate. [12] A micro-nano bubble generator according to any one of [12] to [18] is provided.
[20] In the present invention, the dissolved liquid is an aqueous solution containing carbon dioxide gas, hydrogen gas, or nitrogen gas, and the micro / nano bubble generation according to any one of the above [12] to [18] Providing equipment.
[Effect of the invention]

  The method for generating micro / nano bubbles according to the present invention generates micro / nano bubbles in a large amount only with pure water not containing extra components such as a nucleating agent by generating micro / nano bubbles using water hammer. Therefore, clean washing and sterilization can be performed. This water hammer force is exerted to the maximum by the generating nozzle whose structure and shape are optimized, so that continuous and stable generation of bubbles can be efficiently performed. As a result, the generation amount of not only micro-order bubbles but also small nano-order bubbles can be increased at the same time, and the ability and function of cleaning and sterilization are enhanced more than before.

Since the micro / nano bubble generating device according to the present invention has a generating nozzle and a device configuration capable of stably generating a large amount of bubbles, it should be used as a device for performing clean cleaning and sterilization using pure water. Can do.

Also, in the gas-liquid mixing tank that dissolves gas in liquid, when gas and liquid are put into the pump and sent simultaneously, the amount of gas increases and the gas fills inside the gas-liquid mixing tank and the liquid decreases When this occurs, the gas is not dissolved in the liquid at the nozzle, and the generation of micro / nano valves becomes unstable, and uniform micro / nano valves cannot be generated. This problem can be solved by discharging excess gas outside the gas-liquid mixing tank from a float valve provided inside or outside the gas-liquid mixing tank. By always keeping the amount of liquid and gas within a certain range by this float valve, the generation amount of micro / nano bubbles becomes constant.

Further, in order to perform clean cleaning that prevents generation of metal ions in the liquid contact portion, the pump and / or the pipe and the nozzle portion are made of plastic, preferably fluororesin, so that a highly reliable clean device can be obtained.

The method and apparatus of the present invention contribute to constructing a contamination-free micro / nano bubble generation system. For example, by applying to cleaning of semiconductor wafers, etc., it is possible not only to simplify the process but also to eliminate the need to use chemicals etc. The load can be reduced. Moreover, if it is used for sterilization of food, vegetables, etc., it becomes possible to perform a reliable sterilization process safely and safely.

Front view of micro / nanovalve generation system to which the present invention is applied Micro / nanovalve generation system perspective view to which the present invention is applied Cross section of nozzle for micro / nano valve generation Front view of nozzle for micro / nano valve generation Side view of micro / nanovalve High-speed jet liquid injection nozzle generator Partially enlarged cross-sectional view of the high-speed jet liquid injection nozzle generator Cross section of nozzle that generates micro / nano bubbles Detailed cross-sectional view of the liquid collision nozzle of the nozzle that generates micro / nano bubbles Front view, sectional view, and three-dimensional view of the liquid collision nozzle Nozzle liquid multi-stage collision nozzle Cross section of gas-liquid mixing tank Detailed view of structure of high-efficiency gas-liquid insertion pipe for mixing gas and liquid in gas-liquid mixing tank Cross-sectional view of the float part in the gas-liquid mixing tank Sectional drawing of the gas-liquid mixing tank which has the generating nozzle of this invention inside Sectional drawing which shows another form of the multistage nozzle which generates a micro nano bubble The perspective view and sectional drawing which show the structure of the liquid collision nozzle of this invention The perspective view and sectional drawing which show the structure and shape of the cylinder of the nozzle of this invention The figure which shows the relationship between the flow volume injected from the through-hole of a liquid collision nozzle, and the flow volume discharged | emitted from a discharge outlet Schematic diagram showing the relationship between the diameter of the through-hole of the liquid collision nozzle and the number of bubbles per unit volume The figure which shows the relationship between the diameter of the through-hole of a liquid collision nozzle, and the nozzle flow rate Q The figure which shows the relationship between the bubble generation amount produced | generated by the formation method of the micro nano bubble by this invention, and the particle size of a bubble The figure which shows the relationship between the bubble generation amount produced | generated by the conventional airflow two-phase flow swirling method, and the particle size of a bubble

The best mode for carrying out the present invention will be described below with reference to the drawings.

1 and 2 are a front view and a perspective view of a micro / nanovalve generating system to which the present invention is applied, in which 15 is a bellows cylinder pump, 13 is a pump controller, 14 is a gas-liquid mixing tank, 12 is a pressure sensor, 11 is a nozzle mounting portion for generating a micro / nano valve, 17 is a liquid suction pipe, 16 is a gas suction port, and 18 is a gas suction adjustment valve.

These are arranged as in the perspective view shown in FIG. The bellows cylinder pump 15 having 15 liquid contact parts made of fluororesin is used to adjust the amount of gas using 17 liquid suction pipes and 18 gas suction adjustment valves, and sucked in a state where liquid and gas are mixed inside the pump. In the bellows, the mixture is stirred and dissolved, and compressed to dissolve the gas in the liquid. In the present invention, the bellows cylinder pump 15 may be metal-free, and plastics other than fluororesin, for example, general-purpose plastics such as polyethylene, polypropylene and polyethylene terephthalate, engineering plastics such as polyacetal, polyamide, polycarbonate and modified polyphenylene ether At least one of super engineering such as polyether sulfone, polyphenylene sulfide, polyether ether ketone and liquid crystal polymer may be used. In that case, it is possible to obtain a highly reliable and clean micro / nano bubble generating device by using not only the pump but also the above-mentioned various plastics including the fluororesin in the liquid installation part. In the present invention, in the case where strict metal-free cleaning and sterilization are not required, not only the plastics but also metals and ceramics may be used.

Next, gas and liquid are stirred and pumped into the gas-liquid mixing tank 14 by the pump 15. The pump 15 mainly uses a compressed air activated bellows cylinder pump, but may be an electric type. The gas and the liquid in the gas-liquid mixing tank 14 receive the pressure from the pump 15, and the gas is easily dissolved. That is, the pressure at which gas and liquid are pumped from the pump 15 is checked by twelve pressure sensors. This method by increasing the amount of dissolved gas intends row ready to increase the generation amount of micro-nano bubbles.

The liquid that has been pressure-fed and entered the gas-liquid mixing tank 14 is mixed with gas, dissolved in the liquid, and then sent to the nozzle mounting portion 11 for generating micro / nanovalves. The nozzle mounting portion 11 for generating micro / nanovalves is a portion for connecting a dissolved gas to a nozzle for producing a large number of micro / nanovalves having a diameter of 60 μm or less, preferably 15 μm or less.

At this time, the dissolved state of the gas-liquid is monitored by observing the fluctuation of the liquid pressure between the nozzle 11 and the gas-liquid mixing tank 14 by the 12 pressure sensors. In this way, a stable pressure state necessary for a stable generating nozzle for micro / nanovalves is realized.

  The steps carried out using the micro / nanovalve generator to which the present invention shown in FIGS. 1 and 2 is applied are as follows. The gas / liquid suction step is performed using the gas suction port 16, the liquid suction pipe 17, and the gas suction adjustment bubble 18. The pressure is adjusted by the pressure sensor 12. Next, the step of pressurizing a liquid containing gas using the bellows cylinder pump 15 is a gas / liquid pressurizing step. Subsequently, in order to mix the liquid containing the pressurized gas with a new gas, a process performed using the pump controller 13 and the gas-liquid mixing tank 14 is a dissolved gas enrichment process. Then, after generating nozzles of the present invention described later are connected to the nozzle mounting portion 11 for generating micro / nano valves, micro / nano bubbles are generated. This process is called a dissolved gas refinement process. Micro / nano bubbles are injected from the outside of a cylinder having two or more through-holes through the through-holes at a pressure higher than atmospheric pressure and collide at one point inside the cylinder. Can be generated.

Next, a method for generating a large number of micro / nanovalves from a dissolved solution in which a gas is dissolved will be described. FIG. 3 is a cross-sectional view of the nozzle mounting portion for generating the micro / nanovalve. 1, 2 are the outer case of the nozzle, and the dissolved liquid pumped by the pump is divided into two parts, as shown by the arrows, It is arranged so as to face the outer case, and is fixed with 8 bolts and 9 nuts. A digging is made in the outer case arranged in this way, and three or four high-speed jet liquid jet nozzle generating portions are attached. The liquid discharge flow rate and liquid flow rate are determined by the size of the nozzle hole.

FIG. 4 shows a state where 8 bolts are fastened and fixed by 9 nuts with the assembled nozzle. Water with micro / nano bubbles is discharged in the circumferential direction of the arrow. Figure 5 is a side view of a high-speed jet liquid jet nozzle, micro-nano bubble water is discharged in the circumferential direction.

A method of creating a micro / nanovalve using the water flow from the high-speed jet liquid injection nozzle will be described. Since the pressure is abruptly released from the discharge pressure (0.2 MPa to 0.6 MPa) state of the high-pressure pump 15 ejected from the high-speed jet liquid jet nozzle, the liquids in which the gas dissolves collide with each other, and the force of bursting with the water hammer force Crush the liquid in which the gas is dissolved to make it contain a large amount of micro / nano bulbs. However, the amount of micro / nano bubbles generated may be reduced depending on the release method, but a large amount of micro / nano bubbles can be generated by the method and apparatus according to the present invention.

6A and 6B are a cross-sectional view BB and an external view of the nozzles 3 and 4 for generating micro / nano bubbles. As shown in the cross-sectional view, the nozzle generating portions for jet jets 3 and 4 are centered with 5 center pins that determine the center, aligned with 6 and 7 positioning pins, and fixed. The three or four high-speed jet liquid jet nozzle generating portions generate micro / nano bubbles.

FIG. 7 is an enlarged cross-sectional view of the high-speed jet liquid jet nozzle generating portions 3 and 4 in FIG. 6. Since 3 and 4 are arranged symmetrically in the same shape, they will be described with reference numerals 3 and 4. In order to send the liquid in which gas is dissolved in 3 and 4 as a high-speed jet, it is squeezed with a small hole for a flow path 3a and 4a. The nozzle portions 3b and 4b were arranged so that the jet flow jumped out from the narrow holes 3a and 4a for the flow passages and the jets from the high-speed jet liquid jet nozzle generating portions 3 and 4 collided. Create micro / nano bubbles from dissolved gas. The micro / nano bubbles enclosing the gas produced here diffuse in the circumferential direction of the arrow.

The reason for sending the liquid at high pressure is to increase the speed of the liquid coming out of the small hole. In other words, impact energy is increased by colliding liquid at high speed, and a larger amount of small micro / nano bubbles can be generated.

The force with which F collides. Let the density ρ and S of the liquid be the size of a small hole and the speed of the liquid be V. The relationship F = ρSV ² is established. In order to set F to an optimum value, an optimum design is required in consideration of the relationship between the hole size S and the speed V.

What is important here is that in the case of a pump that produces higher pressures, more micro-nano bubbles may be generated. For example, there are high pressure pumps of 0.5 MPa to 250 MPa, etc., and when such a pump is used, the liquid flow velocity V increases in proportion to the pressure, and the water hammer F increases with the square of V. The amount generated is significantly increased. However, applying such a high-pressure pump to a micro / nano bubble generator is difficult to satisfy various requirements such as light weight, small size, metal free and low maintenance cost.

  The present invention uses a nozzle having a structure as shown in FIGS. 3 to 7 so that the pressure when injecting the dissolved liquid in a gas-liquid mixed state is at least atmospheric pressure (about 0.1 Mpa). For example, the generation amount of micro / nano bubbles can be made equal to or higher than the conventional one. Furthermore, by setting this pressure to 0.2 Mpa or more, it is possible to generate a sufficient amount of micro / nano bubbles for performing clean cleaning and sterilization. Thus, in the present invention, since the lower limit value of the injection pressure of the dissolved liquid can be lowered to 0.2 Mpa as compared with the conventional one, a pump suitable for eliminating the influence of metal contamination, that is, as shown in FIG. 1 and FIG. It is possible to use a compressed air driven or electric bellows cylinder pump 15 made of a simple fluororesin. Moreover, when the compressed air drive type or electric bellows cylinder pump of the present invention is used, if the injection pressure of the dissolved liquid exceeds 0.6 MPa, the generation amount of micro / nano bubbles tends to be saturated. Therefore, the pressure when injecting the dissolved liquid in the present invention is preferably 0.2 to 0.6 MPa.

  The micro-bubble generating nozzle of the present invention is capable of injecting a jet of dissolved liquid at a pressure higher than atmospheric pressure, preferably 0.2 to 0.6 MPa. The nozzle part shown needs to have a diameter of 0.1 to 6.0 mm. Here, the diameter of the nozzle part 3b, 4b from which the jet flow jumps out and the diameter of the nozzle part 3b, 4b are defined as "the exit port" and "the hole diameter of the part where the through hole of the nozzle communicates with the hollow of the cylinder". It is equivalent. In addition, the reason for prescribing the diameters of the nozzle portions 3b and 4b to 0.1 to 6.0 mm will be described in detail in an embodiment described later.

In FIG. 7, the small holes 3a and 4a for the flow path need only have a throttling function for sending the liquid in which the gas is dissolved as a high-speed jet, and are continuously tapered toward the nozzle portions 3b and 4b. It may be formed by. The generation amount of micro / nano bubbles is mainly determined by the diameters of the nozzle portions 3b and 4b. In the present invention, the portions of the small holes 3a and 4a for the flow path can be omitted.

An example of another method for causing a gas-dissolved liquid to collide will be described with reference to FIG. FIG. 8 shows a nozzle for generating micro / nano bubbles, which includes a nozzle case 21, a micro / nano bubble discharge nozzle 22, and a base 24. One or two or more of the liquid collision nozzles 23 are provided as 24 bases. Install and place on top.

FIG. 9 is an enlarged view of a portion where 23 liquid collision nozzles shown in FIG. 8 are arranged. FIG. 10 shows the shape of one of the 23 liquid collision nozzles. The small hole 23a is open toward the center of 23. From this small hole, the liquid entered at high pressure from the arrow P passes through this small hole and collides with the central portion of 23 to generate micro / nano bubbles.

As a result of the experiment, it was found that if the liquid velocity V was controlled, the amount of micro / nano bubbles generated was increased and the lifetime of the bubbles was prolonged. As a measure of the speed V, when the speed exceeds 25 m / sec, a stable micro / nano bubble generating nozzle is obtained.

The same effect can be achieved by reducing the speed by launching from all directions to the center and concentrating the water hammer at the center. That is, in the case of water hammer from four directions, the effect is the same or more even at a speed of 1/2. For example, if F = 2ρSV ² and there are 8 holes and they are concentrated at the center, the force gathered at the center is F = ρS (1/2) ² × 8 = 2ρSV ² . In this way, when the liquid collides and the water hammer is concentrated at the center, if a plurality of small holes are formed in the nozzle, even if the speed V is low, the flow rate increases so that the energy with which the liquid collides is the same. Since the generation amount of micro / nano bubbles is sufficient as long as the energy of collision of the liquid is the same, the pressure for discharging the liquid can be lowered and the amount of generated micro / nano bubbles can be secured.

Figure 10 is spaced small holes 23 a in the circumferential portion of the portion of 23 nozzles barrel in the form of liquid collision nozzles 23, the micro-nano bubbles generated by collisions at the center position of the dissolved solution through this hole. The micro / nano bubbles generated here are ejected in the direction of the arrow Q, and when a large number of liquid collision nozzles 23 are integrated, a large number of micro / nano bubbles emerge, and the nozzle portion 22a of the ejection nozzle 22 shown in FIG. Discharge from.

As shown in FIG. 11, the shape of the liquid collision nozzle 25 is such that small holes 25a are formed in multiple stages, for example , holes are formed in three stages, and the liquid water hammer is generated in three places to create micro / nano bubbles. Since it can be generated in large quantities, it is an effective method for reducing the size and efficiency of the nozzle.

Like the nozzle shown in FIG. 11, the strength of water hammer can be increased by discharging liquid from a plurality of holes. If this technology is used, the amount of micro / nano bubbles generated does not decrease even if the liquid velocity V is low, so there is no need for a pump that discharges liquid at a high pressure, and the burden can be reduced. This makes it possible to develop energy-efficient nozzles that are very useful.

FIG. 12 is a cross-sectional view of the gas-liquid mixing tank 14. FIG. 13 shows an enlarged view of a region E surrounded by a circle in FIG. The conventional gas-liquid mixing tank mixes gas and liquid at high pressure, but when the gas and pure water are mixed and sent by a pump, inside the gas-liquid mixing tank, it is injected and mixed like a fountain at the top I went there. However, since this method has poor mixing efficiency, it is necessary to increase the generation amount of micro / nano bubbles in order to improve the efficiency.

Therefore, as shown in FIG. 12, the gas and the liquid are sent from the pump from the arrow A to the arrow B, and then the gas and the liquid are sent to the gas and liquid insertion pipes 32 and 33. As shown in FIG. By using water hammer generated by colliding liquid from the direction of arrow X and the direction of arrow Y in order to increase the efficiency of gas-liquid mixing discharged from the hole of pipe 32a and the hole of 33a of gas-liquid insertion pipe of 33 In addition, gas and liquid can be mixed efficiently, and the gas-liquid mixed liquid used as a raw material for micro / nano bubbles can be quickly increased and the mixing rate can be increased.

The float 31 shown in FIG. 12 is arranged for the purpose of discharging the excessive gas when the gas / liquid mixture is excessive when the gas enters too much. It discharges safely and works to optimize the amount of gas and liquid. In other words, when excessive gas enters and remains in the gas state, the gas flows into the nozzle and the generation of micro / nano bubbles becomes impossible, and the generation of micro / nano bubbles is eliminated by eliminating the adverse effects of micro / nano bubble generation. The amount can be sent properly and stably.

FIG. 14 shows a cross-sectional view of a portion of the float 31 shown in FIG. The structure of the 31 float pipe is composed of a float tip portion (having a sharp point) of 31a, a reinforcing rib 31b for preventing the float from being crushed by liquid pressure, and a stopper plug 31C.

In order to mix liquid and gas, it is necessary for gas-liquid mixing to increase the gas-liquid contact area to increase the efficiency of the gas dissolved in the liquid. The amount of generated gas will be insufficient due to the fatal gas shortage.

As a result of investigating how much the amount of micro / nano bubbles generated by controlling the amount of liquid and gas increases, the amount of liquid is 60% of the liquid and 40% of the gas by the volume ratio in the gas-liquid mixing tank. For the purpose of automatically controlling the ratio of the two in an ideal balance, the surplus gas is automatically discharged from the excess gas discharge port 48 of the float receiver 47 using the buoyancy of the 31 float liquid. It is necessary to optimize the mixing of dissolved gas and liquid by adjusting, stabilize the generation amount of micro / nano bubbles, and increase the generation amount of micro / nano bubbles. In the present invention, in order to increase the generation amount of micro / nano bubbles, the volume ratio of the liquid and the gas in the gas-liquid mixing tank is within the range of liquid: gas = 50: 50 to 95: 5, and the volume of the liquid. It is preferable to control the ratio to be large. In the present invention, the float 31 may be installed not only inside the gas-liquid mixing tank but also outside. In that case, if the inside and outside of the gas-liquid mixing tank are connected by a connecting pipe or the like, the volume ratio of the liquid and gas existing inside can be controlled.

FIG. 15 is carried out to make the gas-liquid mixing tank more efficient. The basic operation is the same as that shown in FIG. 12 and FIG. 13, and is based on the gas-liquid mixing tank composed of 36, 38, 40, and has a structure that can withstand the internal pressure of the gas-liquid mixing tank. It is to mix gas and liquid efficiently.

Gas-liquid mixing outside the frame 36 shown in FIG. 15, the float 41, the float holder 35, 35 a is a float holder excess gas outlet, has a function of automatically adjusting the excess gas at the tip of the float 41a of the float 41.

In the case of a device that generates a small amount of micro / nano bubbles in the past, micro / nano bubbles are generated once in a water tank, and the micro / nano bubbles generated in the water tank are pumped up again with a pump, and dissolved gas is generated in a gas-liquid mixing tank. The mainstream was the generation of micro / nano bubbles by a method in which they were additionally introduced and circulated over and over again to contain a large amount of micro / nano bubbles.

This method makes it difficult to control the amount of micro / nano bubbles, and further causes problems such as contamination when the circulation is performed. Therefore, there is a demand for an apparatus that can generate a large number of micro / nano bubbles in one operation without using circulation.

Therefore, in the gas-liquid mixing tank used in the present invention, the liquid collision occurs in the gas-liquid mixing state by the action of the micro / nano bubble generating nozzle 38 held by the nozzle holder 39 having the same structure as that shown in FIG. To generate micro / nano bubbles without circulation.

In that case, in order to raise the pressure in the gas-liquid mixing tank, the nozzle 38 arranged in the gas-liquid mixing tank must have a higher flow rate of the dissolved liquid in the gas-liquid mixing state than the nozzle 11 arranged at the tip. It is. If the flow rate of the nozzle 38 is smaller, micro / nano bubbles may not be generated from the nozzle attached to the tip.

The effect of placing the nozzle 38 in the gas-liquid mixing tank can stably generate a large number of micro / nano bubbles in one pass of the gas-liquid mixing tank and the nozzle. Thereby, for example, a micro / nano bubble generating apparatus that is optimal for cleaning semiconductor manufacturing can be provided.

In the present invention, by setting the gas-liquid mixing tank in multiple stages, more micro / nano bubbles can be generated, which is an effective means for generating a large number of bubbles.

FIG. 16 proposes another nozzle method for generating micro-nano bubbles. That is, in order to attach two or more of the small hole nozzles 45, an arrangement is used in which the nozzles are arranged perpendicular to the inflow or discharge direction (longitudinal direction) of the dissolved liquid. This is an arrangement different from that shown in FIG. When arranged as shown in FIG. 16, small nozzles are arranged in the outer cases of 42 and 43, packing of 46 and nozzle holder of 44 as shown in the figure, so that the nozzles of small holes have discharge ports on both sides, so the flow rate is reduced. There is an advantage that it can be secured easily.

In FIG. 16, the gas-liquid mixed solution put in from IN is in a water hammer state with 45 nozzles and is generated on both sides of the nozzle after generating micro / nano bubbles, so the flow rate can be secured and the efficiency is doubled. The energy to create micro / nano bubbles is halved.

A nozzle made by such a water hammer method can be finished into a generator having a long life because liquids collide with each other and damage to the nozzle structure is small.

  The micro / nano bubble generation method and generator of the present invention can use pure water in which impurities such as a nucleating agent are not mixed as a dissolved liquid in order to be applied to cleaning and sterilization of semiconductors and foods. It is a feature. Even if it is necessary to use a nucleating agent or the like in order to increase the amount of micro / nano bubbles generated, the amount mixed in pure water can be greatly reduced. In the present invention, in addition to pure water, for example, spring water such as tap water, well water or natural water can be used in consideration of the supply state and ease of use. Furthermore, in the present invention, in order to improve the cleaning and sterilizing effect, the dissolved liquid may be modified to a liquid that has a stronger oxidizing action or an improved impurity penetration permeability.

  As a method for strengthening the oxidizing action of the above-mentioned dissolved liquid, pure water is mixed with at least one of the group consisting of ozone, oxygen, hydrogen peroxide, chloric acid, perchloric acid and potassium permanganate, and the oxidation is performed. This is a method of preparing an aqueous solution having at least one agent. Among these oxidizing agents, ozone and oxygen are more preferable in the present invention because they have almost no adverse effects as additive components and have a very small environmental load.

  As a method for increasing the peel permeability of the impurities, a method of mixing a gas excellent in the peel permeability of carbon dioxide gas, hydrogen gas or nitrogen gas is preferable. Carbon dioxide gas, hydrogen gas, or nitrogen gas can easily enter the interface between the semiconductor element and impurities such as resist residue attached to the surface due to the generation of micro / nano bubbles, so that the cleaning effect can be greatly enhanced. . Furthermore, since carbon dioxide gas or nitrogen gas is harmless to the human body, it is suitable as a modifier for the dissolved liquid used in the present invention.

  The structure and shape of the nozzle for generating micro / nano bubbles of the present invention will be described in detail using specific embodiments.

[First Embodiment]
FIG. 17 shows the structure and shape of a liquid collision nozzle studied for generating micro / nano bubbles using water hammer force. FIG. 17A corresponds to a comparative example with respect to the embodiment of the present invention, and FIGS. 17B to 17D show the embodiment according to the present invention.

FIG. 17A shows a case in which one hole 49a is formed around a hollow cylinder, and in the case of this comparative example having one hole 49a as a small through hole, the solution discharged at a liquid velocity V was dissolved. Since the liquid directly collides with the wall of 49 tubes, there are few micro / nano bubbles generated, and the wall is destroyed by the impact of the liquid because it hits the wall.

The liquid collision nozzle shown in FIG. 17 (b) is formed with two holes 50a as through-holes. In this embodiment, the liquid collision nozzle is located at a position opposed to the collision of the dissolved liquid discharged at the liquid velocity V. Since 50a is arranged, a collision at a speed of 2V can be realized. The energy of the collision is higher than that in the comparative example of FIG.

The liquid collision nozzle shown in FIG. 17 (c) is formed with three holes 51a as through-holes. In this embodiment, the liquid collision nozzle of 120 degrees is used to collide the dissolved liquid discharged at the liquid velocity V. By drilling three holes in the position, the liquid that comes out at the speed of V triples the energy at the center clash. That is, when the collision is made using three holes, the same energy can be obtained even if the speed V is reduced by 20% if the same energy as that of the previous two holes is sufficient. Since the speed V is determined by the pressure of the pump, micro / nano bubbles can be generated even if the pressure is reduced.

The liquid collision nozzle shown in FIG. 17D is formed with four holes 52a as small through holes. In this embodiment, the liquid collision nozzle of 90 degrees is used to collide the dissolved liquid discharged at the liquid velocity V. By drilling four holes in the position, the liquid coming out at the speed of V is quadrupled in energy at the center clash. That is, when collision is performed using four holes, if the same energy as that of the previous two holes is sufficient, the same energy can be obtained even if the speed V is reduced by 30%. Since the speed V is determined by the pressure of the pump, micro / nano bubbles can be generated even if the pressure is reduced.

The liquid collision nozzle shown in FIG. 17 (e) is formed with five holes 53a as through-holes. In this embodiment, the liquid collision nozzle of 72 degrees is used to collide the dissolved liquid discharged at the liquid velocity V. By drilling 5 holes in the position, the liquid that comes out at the speed of V becomes 5 times the energy at the collision point of the center. That is, when the collision is made using five holes, the same energy can be obtained even if the speed V is decreased by 40% if the same energy as the previous two holes is sufficient. Since the speed V is determined by the pressure of the pump, micro / nano bubbles can be generated even if the pressure is reduced.

As described above, micro / nano bubbles that could not be created without using a high-pressure pump by optimizing the structure and arrangement of the through-holes of the liquid collision nozzle are generated in large quantities even when the pump pressure is 0.2 MPa. Energy saving can be realized.

[Second Embodiment]
In the liquid collision nozzle for generating micro / nano bubbles of the present invention, the relationship between the diameter of the micro / nano bubble discharge port provided at the end of the hollow cylinder and the diameter of the cylinder at the portion where the through small holes are arranged in the circumferential direction Will be described with reference to FIG.

FIG. 18A shows a liquid collision nozzle having two holes 54a. Micro / nanobubbles formed by liquid collision by increasing the diameter of the portion where the jetting liquid collides (the portion where the through hole is formed) to D1 and the diameter of the discharge port to D2 in the cylinder of 54 nozzles. Immediate pressure is applied. This makes it possible to control the composition of micro / nano bubbles. In other words, it becomes a means for controlling the particle distribution of the generated micro / nano bubbles, and is effective in making the particles finer.

  The liquid collision nozzle shown in FIG. 18 (b) has two holes 55a. The diameter of the portion of the 55 nozzle cylinder where the spray liquid collides is reduced to D3, and the diameter of the discharge port is increased to D4. To do. In this way, since the micro / nano bubbles generated by the collision are not applied with pressure, the particle distribution of the micro / nano bubbles that expand when they are generated becomes slightly larger.

  In the present invention, either of the nozzles having the structure shown in FIG. 18 can be used. However, in FIG. 18A, the diameter of the discharge port is smaller than the diameter of the colliding part in the nozzle cylinder. For this reason, the pressure of the dissolved liquid near the protrusion is increased. Therefore, although it is effective for miniaturization of micro / nano bubble particles, the generation of bubbles is somewhat hindered, and the generation amount of bubbles is reduced or the bubbles are generated with a delay in time away from the protruding opening. A phenomenon may appear. On the other hand, the nozzle having the structure shown in FIG. 18B is capable of generating a large amount of bubbles stably because the pressure is released at the discharge port. Since miniaturization of the micro / nano bubble can be adjusted by the diameter of the through hole of the nozzle, the nozzle shown in FIG. 18B is suitable in the present invention.

[Third Embodiment]
For the liquid collision nozzle shown in FIG. 18 (b), the relationship between the impact nozzle diameter and the micro / nano bubbles when the liquid pressure is constant and pure water containing ozone (50 ppm ) is used as the dissolved liquid. This will be described with reference to FIGS.

FIG. 19 is a diagram showing the relationship between the flow rate ejected from the through hole of the nozzle 56 and the flow rate discharged from the discharge port. In FIG. 19, the dissolved liquid sprayed from the through small hole 56a of the nozzle 56 at a speed of V1 is ejected at a liquid amount Q1 from one hole 56a per second, and then collides to generate micro / nano bubbles. Thereafter, the liquid Q2 is discharged from the discharge port of the 56 pipe at a speed of V2 with a liquid amount Q2 per second. Here, the flow rates Q1 and Q2 have the same value.

FIG. 20 shows the relationship between the diameter of the through hole of the liquid collision nozzle and the amount of micro / nano bubbles generated. Here, the amount of micro / nano bubbles generated was plotted as the number of bubbles generated per unit volume of the dissolved liquid. In FIG. 20, when the diameter of the through hole of the liquid collision nozzle increases, V1 decreases and the liquid amount Q1 increases. In that case, the generation amount of microbubbles (60 microns or more) increases, but the generation amount of nanobubbles decreases. On the other hand, when the diameter of the through hole of the thermal collision nozzle is reduced, the liquid amount Q1 is reduced. In that case, the generation of microbubbles (60 microns or more) decreases and V1 increases, but the generation amount of nanobubbles (2 microns or less) increases.

Thus, the diameter of the through hole of the liquid collision nozzle is an important factor that determines the performance of the micro / nano bubble. Although there are differences depending on the nature of the gas to be dissolved with the liquid, since the tendency is as described above, the amount of micro / nano bubbles can be controlled by the through-hole diameter of the liquid collision nozzle.

FIG. 21 shows the relationship between the through hole diameter of the liquid collision nozzle and the flow rate Q. While the liquid pressure is constant, the relationship between the small through hole diameter of one liquid collision nozzle and the flow rate Q is proportional to the square of the liquid collision nozzle diameter, but the liquid velocity V is 2 of the liquid collision nozzle diameter. Since it is inversely proportional to the power, it is as shown in FIG. By determining the number of holes of the liquid collision nozzle in consideration of the required flow rate, the diameter of the through hole of the nozzle can be optimized.

From FIG. 20, in the present invention, the through-hole diameter of the nozzle needs to be 0.1 to 6.0 mm. When the through-hole diameter of the nozzle is less than 0.1 mm, the amount of bubbles with a small particle size of about 60 μm or less increases, but the amount of bubbles larger than the particle size rapidly decreases. Occurrence almost disappears. In addition, when the through-hole diameter of the nozzle exceeds 6 mm, the total amount of bubbles to be generated increases, but conversely, the generation amount of small particle bubbles of about 60 μm or less rapidly decreases to 500 / ml or less. The effects of can not be fully achieved. In the present invention, in order to increase the generation amount of micro / nano bubbles to 1000 / ml or more, it is more preferable to provide the through-hole diameter of the liquid collision nozzle in the range of 0.1 to 3 mm.

[Fourth Embodiment]
Using distilled water as the dissolved liquid, micro / nano bubbles were generated using the micro / nano bubble generating apparatus of the present invention shown in FIGS. The nozzle has the same structure as that shown in FIGS. 3 and 4, and the nozzle portions 3 b and 4 b were produced in a straight shape with small through holes having a diameter of 0.5 mm. Further, as a comparative example, micro / nano bubbles were generated using the same distilled water as the dissolved liquid by a conventional two-phase air flow swirling method. FIG. 22 and FIG. 23 show the relationship between the bubble generation amount and the bubble particle size generated by the micro / nano bubble forming method and the two-phase flow swirl method according to the present invention, respectively. The bubble generation amount is represented by the number of bubbles per unit volume of distilled water (number / ml). The bubble generation amount and particle size were measured at room temperature using an in-liquid particle counter. 22 and 23 do not show the nano region as the bubble particle size, but it is because it is optically difficult to measure the number of particles in the nano region.

Comparing the results shown in FIGS. 22 and 23, the generation method of micro / nano bubbles according to the present invention has a larger number of bubbles over the entire region having a particle diameter of about 60 μm or less as compared with the conventional two-phase flow swirl method. I understand. In particular, a significant difference is observed in the region where the bubble particle size is 20 to 40 μm. Further, when both methods are compared in a region where the bubble particle size is 2 to 10 μm, the number of bubbles generated in the present invention is substantially the same as or slightly larger than the conventional method. By analogy from the results of the number of bubbles generated in a region having a small particle size, it is considered that the present invention has a large number of bubbles even in the submicron region, that is, the nano region. Actually, when the micro-nano bubble generating device according to the present invention is used for cleaning semiconductor wafers or sterilizing foods such as vegetables, even in a state where the bubbles disappeared over time, it became a transparent solution. It was confirmed that the effect of washing or sterilization continued. That is, the present invention provides an effect that the cleaning or sterilizing effect due to the generation of micro / nano bubbles can be continued longer than the conventional method. This is considered to be because the generation amount of nanobubbles of 1 μm or less is large, and the existence thereof exerted such an effect.

  As described above, the method for generating micro / nano bubbles according to the present invention generates micro / nano bubbles by using water hammer force, so that micro / nano bubbles can be generated only with pure water that does not contain extra components such as a nucleating agent. Since it can be generated in large quantities, clean washing and sterilization can be performed. This water hammer force is maximized by a generating nozzle that optimizes the structure and shape and a generator that can stably generate a large amount of bubbles, so that continuous and stable generation of bubbles can be efficiently performed. it can. As a result, the generation amount of not only micro-order bubbles but also small nano-order bubbles can be increased at the same time, and the ability and function of cleaning and sterilization are increased more than ever.

Further, in order to perform clean cleaning that prevents generation of metal ions in the liquid contact portion, the pump and / or the pipe and the nozzle portion are made of plastic, preferably fluororesin, so that a highly reliable clean device can be obtained. Therefore, the micro / nano bubble generating apparatus of the present invention can be used for clean cleaning of a semiconductor wafer or the like. Conventionally, cleaning of semiconductor wafers is performed using neutralization with strong acid or alkali, rinsing with pure water, etc., and the process is complicated. Can solve this problem. Furthermore, the burden of processing chemicals and the like is eliminated, and the manufacture of semiconductors has great industrial value such as small equipment and a compact semiconductor process.

  Also, in cleaning semiconductor wafers, not only pure water but also gases with large oxidizing ability such as ozone and oxygen, or those that generate micro / nano bubbles by using a peeling penetrant such as carbon dioxide or nitrogen gas are washed. In addition to greatly improving the cleaning effect, the cleaning process is very simple, the size of the cleaning device can be reduced, and the environment is friendly. Furthermore, the burden of processing chemicals and the like is eliminated, and the manufacture of semiconductors has great industrial value such as small equipment and a compact semiconductor process.

According to the present invention, micro / nano bubbles manufactured from a clean system in which a pump and a wetted part are made of a fluororesin are used, so that they can be used for medical treatment and the like. ing.

Furthermore, the ability of cleaning and sterilization by micro / nano bubbles using oxygen or ozone as a gas can be used not only for the semiconductor field but also for foods, vegetables and the like. Therefore, there is a possibility that the range of application may be expanded in fields such as agriculture and fishery. In the industrial field, a resin is directly injection-molded on a metal that has been cleaned and oxidized with ozone micro / nanobubbles to form the metal. The resin can be tightly integrated, or the metal and the resin can be bonded well using an adhesive, and conversely, the surface of the resin can be cleaned and oxidized to achieve good metal plating. The nanobubble generation method, the generation nozzle, and the generation apparatus are extremely superior.

1: Nozzle outer case 2: Nozzle outer case 3: High-speed jet liquid injection no-nozzle generator 4: High-speed jet liquid injection no-nozzle generator 5: Center pin 6: Positioning pin 7: Positioning pin 8: Bolt 9: Nut 11: Nozzle Nozzle mounting part 12: Pressure gauge 13: Controller 14: Gas-liquid mixing tank 15: Bellows cylinder pump 16: Gas suction port 17: Liquid suction pipe 18: Gas suction adjustment valve 21: Nozzle case 22: Micro / nano bubble discharge nozzle 23: Liquid collision nozzle 24: Liquid collision nozzle mounting base 25: Nozzle with multiple liquid collision nozzles 31: Float 32: Gas-liquid insertion pipe 33: Gas-liquid insertion pipe
34: Teflon side wall
35: Excess gas discharge port 36: Gas-liquid mixing outer frame 37: Nano bubble generating nozzle lid 38: Micro / nano bubble generating nozzle 39: Micro / nano bubble generating nozzle holder 40: Outer frame 41: Float 42: Horizontal nozzle holder 43: Horizontal nozzle Outer frame 44: Horizontal type nozzle Outer frame 45: Nozzle 46: Packing 47: Float receiver 48: Excess gas discharge port 49: 1 hole liquid collision nozzle 50: 2 hole liquid collision nozzle 51: 3 hole liquid collision nozzle 52: 4 hole liquid Collision nozzle 53: 5-hole liquid collision nozzle 54: Collision nozzle 55: Collision nozzle 56: Collision nozzle

Claims (20)

This is a method for generating micro / nano bubbles using water hammering force, in which a dissolved liquid in a gas-liquid mixed state is passed through the through small holes from the outside of a cylinder having two or more through small holes in the circumferential direction. when jetting at pressures above atmospheric pressure, the dissolved liquid was injected from the tubular radial cross-section and each opening being positioned to face the two or more through-eyelet on the same plane parallel to the tube A method of generating micro / nano bubbles, characterized by generating micro / nano bubbles by causing collisions so that water hammer concentrates in the center . A gas / liquid suction step, a gas / liquid pressurization step, a dissolved gas enrichment step in which a liquid containing the pressurized gas is mixed with a new gas, and a gas adjusted in the dissolved gas enrichment step the dissolved solution in the state of the liquid mixture, possess a dissolved gas refining step of injecting at atmospheric pressure or a pressure from the outside of the cylinder through the through eyelet having 2 or more through eyelet circumferentially diameter of the tube The micro- particles are made to collide with the dissolved liquid sprayed from the openings of the two or more through-holes arranged so as to face each other on the same plane parallel to the direction cross section so that the water hammer is concentrated on the center of the cylinder. The method for generating micro / nano bubbles according to claim 1, comprising generating nano bubbles.   The pressure at or above atmospheric pressure when injecting is 0.2 to 0.6 MPa, and the through hole has a hole diameter of 0.1 to 6.0 mm at a portion communicating with the hollow of the cylinder. Item 3. The method for generating micro / nano bubbles according to Item 1 or 2.   4. The solution according to claim 1, wherein the dissolved liquid is an aqueous solution having at least one of the group consisting of ozone, oxygen, hydrogen peroxide, chloric acid, perchloric acid and potassium permanganate. 2. A method for generating micro / nano bubbles according to 1.   The method for generating micro / nano bubbles according to any one of claims 1 to 3, wherein the dissolved liquid is an aqueous solution containing carbon dioxide gas, hydrogen gas, or nitrogen gas. A generating nozzle used to generate micro / nano bubbles using water hammer force, each of which has a hollow cylinder and two or more through small holes in the circumferential direction of the cylinder in the radial direction of the cylinder The two or more through small holes arranged so as to face each other on the same plane parallel to the cross section, and a micro / nano bubble discharge port at at least one end of the cylinder, and the through small hole has a cross-sectional center of the through small hole A micro / nano bubble generating nozzle, wherein all of the extended lines passing through the section intersect with each other at the center of the cylinder .   The nozzle for generating micro / nano bubbles according to claim 6, wherein the nozzle has two or more hollow cylinders.   The micro-nano bubble generating nozzle according to claim 7, wherein two or more hollow cylinders are arranged in parallel or perpendicular to the inflow or discharge direction of the dissolved liquid.   9. The micro / nano bubble generating nozzle according to claim 6, wherein in the hollow cylinder, the two or more through small holes are provided in two or more stages in the longitudinal direction of the cylinder.   10. The micro / nano bubble generating nozzle according to claim 6, wherein the through hole has a hole diameter of 0.1 to 6.0 mm at a portion communicating with the cavity of the cylinder.   In the hollow cylinder, the diameter of the micro / nano bubble discharge port provided at at least one end of the cylinder is the same as the diameter of the cylinder where the through small holes are arranged in the circumferential direction, or more than the diameter of the cylinder The micro / nano bubble generating nozzle according to claim 6, wherein the nozzle is large.   Means for sucking gas and liquid respectively, means for simultaneously pressurizing and transporting the gas and liquid, and enriching the dissolved gas by mixing the liquid containing the transported gas with a new gas A gas-liquid mixing tank for generating a micro-nanobubble using a dissolved liquid in a gas-liquid mixing state in the gas-liquid mixing tank, and a micro having a generating nozzle according to any one of claims 6 to 11 A micro / nano bubble generating device having nano bubble generating means.   13. The micro / nano bubble generating apparatus according to claim 12, wherein in the micro / nano bubble generating means, the dissolved liquid is jetted at a pressure of 0.2 to 0.6 MPa through a through hole of the generating nozzle.   The gas-liquid mixing tank has nozzles for generating the micro / nano bubbles, and the liquid containing the gas that is transported by the pressurizing and transporting means is discharged into the gas-liquid mixing tank by the generating nozzle. 14. The device for generating micro / nano bubbles according to claim 12 or 13, wherein:   The gas-liquid mixing tank discharges excess gas from the gas-liquid mixing tank to keep the amount of liquid and gas and the pressure in the gas-liquid mixing tank always within a certain range. The micro / nano bubble generating apparatus according to claim 12, further comprising a float valve outside.   The micro / nano bubble generating device according to any one of claims 12 to 15, wherein at least one of a pump and a pipe through which the gas-liquid mixed solution passes is made of plastic. .   17. The micro / nano bubble generating device according to claim 16, wherein at least one of a pump and a pipe through which the gas-liquid mixed solution passes is made of a fluororesin.   18. The micro of any one of claims 12 to 17, wherein the means for pressurizing and transporting the liquid containing the gas is a device using a compressed air activated or electric bellows cylinder pump.・ Nano bubble generator.   19. The solution according to claim 12, wherein the dissolved liquid is an aqueous solution having at least one of the group consisting of ozone, oxygen, hydrogen peroxide, chloric acid, perchloric acid, and potassium permanganate. The micro / nano bubble generator described in 1.   19. The micro / nano bubble generating apparatus according to claim 12, wherein the dissolved liquid is an aqueous solution containing carbon dioxide gas, hydrogen gas, or nitrogen gas.

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