Method and apparatus for generating high-concentration fine bubble water.

Abstract

Current fine bubble (FB) generators fall under broad categories such as microbubble (MB) or ultrafine bubble (UFB). The optimal bubble size depends on the application. Just as MB and UFB each have their advantages, there are differences in characteristics depending on the size of the MB bubbles. Further classification may be necessary depending on the application. Additionally, increasing the concentration of the FB water may be required. [Solution] In a method for generating high-concentration fine bubble (FB) water, the fine bubble water generation device uses an FB water generator in a porous pipe housed in a sealed gas pipe. Various gases, such as air, are supplied to the sealed gas pipe at high pressure. This provides the FB sealing gas, significantly increasing the pressure difference between the inside and outside of the porous pipe. The size of the bubbles that permeate is controlled by the permeability coefficient determined by the porous structure (porosity, pore size). Multiple FB water generators with different permeability coefficients are prepared. Furthermore, this method significantly increases the concentration of FB water.

Description

Technical Field

[0001] The present invention relates to a method for generating a large amount of high-concentration fine bubble water and an apparatus for generating the same.

Background Art

[0002] Fine bubbles are a general term for microbubbles with a particle size of 100 μm to 1 μm and ultrafine bubbles with a particle size of less than 1 μm. Fine bubbles have characteristic properties that cannot be obtained with ordinary milli- and centibubbles. For example, aeration uses air millibubbles to supply oxygen and is used for water purification. Similarly, if fine bubbles are used, they stay in water longer than ordinary millibubbles. Therefore, the amount of oxygen scattered into the atmosphere is small, and the supply of oxygen lasts longer. In particular, ultrafine bubbles can stay in water for a long time, sometimes for several months.

[0003] A particularly notable function of microbubbles is the function of generating free radicals when they disappear and decomposing various chemical substances present in an aqueous solution. A particularly notable function of ultrafine bubbles is the long-term gas encapsulation function according to the purpose. For example, air has the effect of improving the efficiency of washing, cleaning, and hydroponics. Oxygen has the effects of fish farming, microbial activation, and an increase in the amount of dissolved oxygen. Nitrogen has the effects of antioxidant protection and freshness retention. In addition, the bioactive function promotes plant growth by making it easier for plants to absorb nutrients from the roots in agriculture, and in fish farming, it increases the amount of dissolved oxygen in the culture pond and improves productivity.

[0004] Currently, the use of fine bubbles is spreading in many fields such as food, medicine, agriculture, fisheries, manufacturing, and the environment. Many fine bubble application technologies meet one of the 17 goals set by the United Nations' Sustainable Development Goals (SDGs) in 2015 and are expected to be effective technologies for achieving the SDGs.

[0005] Various devices have been developed to generate ultrafine bubbles, also known as microbubbles or ultrafine bubbles. For example, methods for generating nano-sized bubbles with high stability in liquid include surfactant-added micropore methods and ultrasonic cavitation methods. Ultrafine bubble generators that utilize bubble generation through flow path shapes such as high-speed swirling, pressurized dissolution, and ejector types are also known.

[0006] When using micropores or ultrasound as methods for generating ultrafine bubbles as described above, it is difficult to produce high-quality, high-concentration bubbles, and the flow rate is limited. Therefore, there are problems with cost and other constraints regarding the feasibility of applying these technologies in the aforementioned fields. Furthermore, while ultrafine bubble generators that use bubble generation action based on flow path shapes such as high-speed swirling, pressurized dissolution, and ejector types can generate ultrafine bubbles relatively easily, there is a problem in obtaining ultrafine bubbles of a high concentration sufficient to achieve high performance in each field. (See Patent Document 1)

[0007] In 2022, a new technology was announced that solved the problem of generating ultrafine bubbles at high concentrations, as described above, by realizing an ultrafine bubble generator and device. This new technology's ultrafine bubble generation method is a turbulent high-pressure bursting type using a special nozzle. The concept for this method is said to be inspired by the intense mixing and high-speed ejection of aircraft jet engines. The device's structure consists of an outer shell that forms the flow channel structure, and inside, a pair of derivative flow channels for the gas-liquid mixed fluid with a special streamlined cross-section, called the flow channel internal body, are provided. This device generates intense turbulent vortex flow, cutting, severing, and crushing bubbles, thereby generating ultrafine bubbles down to nano-size. Furthermore, it successfully generates ultrafine bubbles more efficiently than conventional technology, reducing running costs. Its features include high quality, low running costs, high-volume generation in a short time, a greater number of ultrafine bubbles than existing commercially available products, and the ability to control bubble size and flow rate from micro to nano-size. (See Patent Document 1)

[0008] In 2024, a new technology that solves the above problem in a different way was patented. This ultrafine bubble (UFB) generator incorporates a variable-speed rotary agitator into a UFB generation tank, which is filled with sandy material. By supplying gas and water to the tank at high pressure, the gas, water, and sandy material are liquefied. By rapidly rotating this liquefied layer with the rotary agitator, the gas is confined within the interstitial water of the liquefied layer and then fragmented into ultrafine particles. Furthermore, by using sandy steel slag as the sandy material, in addition to the UFB effect, it is intended to suppress methane generation due to silica, lime, and iron oxide, and improve crop yields, thus achieving both "improved productivity in paddy rice cultivation and measures against global warming." (See Patent Document 2)

[0009] Generators using special nozzle systems for ultrafine bubbles have difficulty generating ultrafine bubbles. Most are microbubble generators. A common characteristic of nozzle systems is how to generate intense turbulent vortices. Patent document 1 solves this problem. We will compare the new technologies in Patent document 1 and Patent document 2. There are three major differences. The first is the fluid of the turbulent vortex. The former is a gas-water mixed fluid, and the latter is a gas-water-sand-like material mixed fluid. The second is the difference in the space where the turbulent vortex is generated. In the former, it is a space limited by the outer shell of the generator and the internal components of the flow path. In the latter, in addition to the space limited by the outer shell of the generator, it is a space constrained by the gaps between the sand-like material. The third is the difference in the mechanism for fragmenting the gas into ultrafine bubbles. In the latter, in addition to the turbulent vortex, there is a shear force due to the interaction of the stirring blade and baffle plate, which is expected to have a fragmentation effect greater than that of the turbulent vortex. The gas-water-sand-like material mixed fluid undergoes shearing 500 to 2000 times per minute during the ultrafine bubble generation process, and the number of shearing cycles can be set. Based on the above, and considering the initial and running costs, Patent Document 1 appears to be suitable for the use of fine bubbles in small volumes of water, while Patent Document 2 appears to be suitable for the use of fine bubbles in large volumes of water. [Prior art documents] [Patent Documents]

[0010] [Patent Document 1] Patent No. 7092358 [Patent Document 2] Japanese Patent Application No. 2024-214037 [Overview of the project] [Problems that the invention aims to solve]

[0011] Methane, one of the greenhouse gases, has a greenhouse effect approximately 27 times greater than carbon dioxide, and rice cultivation accounts for about 42% of methane emissions in Japan. The use of ultrafine bubbles (UFBs) is expected to be a method to reduce methane emissions from rice cultivation. The purpose of Patent Document 2 is to advance a project to achieve both improved agricultural productivity and measures against global warming. Specifically, it concerns paddy rice cultivation aimed at suppressing methane gas generation. For this purpose, the development of a device that generates a large amount of high-concentration UFBs in a short time is essential. The aforementioned project sets a target value of 1.0% for the UFB concentration generated by the UFB water generator. Currently, most commercially available fine bubble generators are microbubble generators. While ultrafine bubble generators exist, they often produce low concentrations. With current technology, a high concentration of ultrafine bubbles (UFBs) is considered to be 2.0 × 10⁻⁶ in number concentration. 9 The number concentration is approximately 1.0 × 10¹⁶ particles / mL. Now, assuming the average diameter of UFB is 100 nanometers, converting the number concentration to a percentage gives approximately 1.0 × 10¹⁶ particles. -6 It's around a percent. When converted to a percentage, it's a minuscule amount. However, even low concentrations of UFB water have been recognized as effective in various industries. The target UFB concentration of 1.0% is indeed an extremely high concentration.

[0012] The apparatus described in Patent Document 2 appears to be the most promising apparatus for "generating a large amount of high-concentration UFB in a short time." The application area of ​​this apparatus is the utilization of fine bubbles when handling extremely large volumes of water. For example, rice irrigation, large-scale aquaculture, and water purification of polluted water in rivers, dams, lakes, and reservoirs. However, the aforementioned apparatus is characterized by the fact that the UFB generation tank is filled with sand-like material. While debris in the raw water is removed by the screen, fine pollutant particles are difficult to remove. Maintenance requires washing the sand-like material as needed. Water purification of polluted water accompanied by odor requires an extremely high washing frequency and is not necessarily the apparatus's strong suit. Also, handling small volumes of water is not cost-effective. In short, the apparatus in Patent Document 2 is an apparatus that generates UFB specialized for paddy rice cultivation. Therefore, the problem that this invention aims to solve is to significantly reduce initial and running costs by eliminating the need to wash the sand-like material. Furthermore, by miniaturizing the apparatus, it is a versatile apparatus that generates high-concentration UFB and can be used on a small scale. Another challenge is that current fine bubble (FB) generators are categorized broadly as either microbubbles (MB) or ultrafine bubbles (UFB). The optimal bubble size depends on the application. Just as MB and UFB each have their advantages, there are differences in characteristics depending on the size of the MB. Further classification may be necessary depending on the application. The means that this invention aims to solve...

[0013] In a method for generating high-concentration fine bubble (FB) water, a two-stage FB generation system is used in the fine bubble water generation apparatus, employing a porous pipe FB water generator. When water flows through a pipe when it is full, the pressure on the pipe decreases according to the flow velocity. This is Bernoulli's principle. The first-stage generating porous pipe is used regardless of whether the target water is wastewater or not, making maximum use of this principle. The second-stage ultra-fine bubble water generator (generation tank) is used as needed. The generation tank is filled with graded sand and gravel. In paddy rice cultivation, this is changed to graded steel slag.

[0014] The optimal bubble size varies depending on the application. Furthermore, the concentration of FB water can be further increased. This method utilizes the porous structure of the porous pipe. In the method for generating high-concentration fine bubble (FB) water, the fine bubble water generator uses an FB water generator in a porous pipe housed in a sealed gas pipe or pressure tank. Various gases, such as air, are supplied at high pressure to the sealed gas pipe. This provides the FB sealing gas, significantly increasing the pressure difference between the inside and outside of the porous pipe. The size of the permeable bubbles is controlled by the permeability coefficient, which is determined by the porous structure (porosity, pore size). Multiple FB water generators with different permeability coefficients are prepared, and the optimal bubble size is selected according to the application. The sealed gas pipe or pressure tank method significantly increases the concentration of FB water.

[0015] In an apparatus used for generating high-concentration fine bubble (FB) water, the apparatus consists of a water supply pressure pump, an FB water generation porous pipe, and a water supply pipe connecting them. The generation porous pipe creates a pressure difference along its entire length by using the suction force of gas into the pipe and the flow velocity of the water flow. The size of the generated bubbles is limited by the permeability function of the porous structure (porosity, pore diameter), resulting in FB bubbles with a diameter less than or equal to a predetermined gas diameter that are incorporated into the water flow.

[0016] In order to generate a large amount of the desired high-concentration FB water in a short time using this device, the following two requirements must be set. The first is the requirement that gases of a predetermined diameter or smaller can permeate the porous pipe, which is determined by the permeability coefficient (porosity, pore size) and the thickness of the pipe. The second is the requirement for the amount of air permeability of the porous pipe, which is determined by the diameter and length of the porous pipe and the water flow velocity. Here, the time it takes for the flowing water to pass through the porous pipe is extremely short.

[0017] The principle of the porous pipe generation of this invention is that atmospheric pressure Pa acts on the outer surface of the pipe, while a water flow moves at high velocity V on the inner surface of the pipe. The pressure inside the pipe decreases to P according to the flow velocity V. Due to the pressure difference Pa-P, air is drawn in through the pores and incorporated into the water flow as ultrafine bubbles corresponding to the pores. The requirement that independent gases (bubbles) smaller than a set gas diameter can permeate is determined by the permeability coefficient and the pipe thickness. The size of the diameter of the generated FB is important. Since there is little data on the permeability coefficient, the diameter is predicted and converted from the water permeability coefficient. The permeability coefficient is a larger value than the water permeability coefficient. The pipe thickness is a concern because the bubbles drawn in are not necessarily spherical; they can be deformed spheres such as cylinders. Therefore, if the pores are made thicker, the bubble passages become winding, and the deformed spheres will break off along the way and pass through as normal spheres. The required amount of air permeability is determined by the diameter and length of the porous pipe and the water flow velocity.

[0018] For example, the particle diameter at the boundary between sand and silt is 0.075 mm. The size of the void between these particles is approximately half the particle diameter. The diameter of air bubbles that can pass through is 0.037 mm or less. The permeability coefficient at the boundary between sand and silt is approximately 10 -4 It is m / s. As a guideline, the permeability coefficient is 10 -4 The fine bubbles generated from the porous pipe at m / s are microbubbles with a diameter of 0.037 mm or less. The particle diameter at the boundary between silt and clay is 0.005 mm. The diameter of bubbles that can pass through the gaps between these particles is 0.0025 mm or less. The permeability coefficient at the boundary between silt and clay is approximately 10 -7 It is m / s. As a guideline, the permeability coefficient is 10 -7 Fine bubbles generated from a porous pipe with a diameter of m / s are microbubbles with a diameter of 0.0025 mm or less. Note that bubbles with a diameter of 0.1 mm to 0.001 mm (1 μm) are called microbubbles, and those with a diameter of 1 μm or less are called ultrafine bubbles; fine bubbles are a general term encompassing all of these.

[0019] The FB water generator of this invention has a porous pipe that is the same diameter as, or slightly smaller than, the water supply pipe. The intention to slightly reduce the diameter is to increase the flow velocity. The water flow simply moves at high speed within this porous pipe. The pipe diameter is set as appropriate, for example, 60 mm. In any case, it is a large-diameter generator compared to conventional nozzle-type FB generators. Therefore, there is no concern whatsoever about clogging by sludge or foreign matter. Furthermore, the pores of the porous pipe allow gas to be drawn inward in one direction, and the water flow containing foreign matter does not move from the inner surface to the outer surface of the pores. Therefore, there is no clogging of the pores and it is maintenance-free. It is highly effective in purifying polluted water in rivers, dams, lakes, reservoirs, etc.

[0020] In the apparatus used for the aforementioned method of generating high-concentration FB water, the apparatus houses the FB water generation porous pipe in a sealed gas pipe. The apparatus is characterized by supplying various gases to the sealed gas pipe at high pressure, thereby increasing the supply of FB sealing gas and the pressure difference between the inside and outside of the porous pipe along its entire length. Here, the various gases include air, oxygen, ozone, nitrogen, etc. FB can be given various functions by sealing various gases into bubbles according to the purpose. While some literature suggests that only UFB has this bubble sealing characteristic, microbubbles also have similar characteristics. However, their short lifespan means a shorter sealing time. What should be emphasized here is the high pressure of the gas. Increasing the velocity of the flowing water can increase the pressure difference between the inside and outside of the porous pipe, but conversely, the passage time of the flowing water through the porous pipe is shortened, limiting the amount of FB that the flowing water can absorb. Therefore, the function of the high-pressure gas plays an extremely important role here. Storing the porous pipe in a pressure tank with multiple layers of winding is intended for the same reason. A pressure tank that can store long porous pipes by rolling them up is suitable. For example, if you roll a 60mm diameter porous pipe into 60cm diameter sections and stack them 10 times, the total length will be 18.8m.

[0021] In the apparatus used for the method of generating the high-concentration FB water described above, the apparatus comprises a water supply pressure pump, a porous pipe for generating FB water, a booster pump, a tank for generating ultra-fine bubble (UFB) water, and water supply pipes connecting these components. The tank for generating UFB water is filled with particle-size adjusting sand and gravel, and the pipe connected to the tank has a constricted tip to form a nozzle. A mixed fluid of high-concentration FB and water jets out from this nozzle and collides with the particle-size adjusting sand and gravel. The apparatus used for the method of generating the high-concentration UFB water is characterized in that the generation of ultra-fine gas is achieved through two steps of a generation porous pipe and a generation tank.

[0022] The apparatus is intended to utilize UFB water in paddy rice cultivation. The apparatus in Patent Document 2 was filled with sand-like substances. This apparatus uses particle-size adjusting sand and gravel. The ultra-fine crushing energy of the gas is, in the former case, the shear force and intense overcurrent caused by the interaction between the stirring blades and the baffle plate due to the rotational energy of the electric motor. In order to rotate the stirring blades, it was necessary to use sand-like substances. In the latter case, the porous pipe is already in a high-concentration fine bubble water state. This is further crushed into ultra-fine particles. Using a pump as the power source is for cost reduction. The means of crushing is the intense jet collision of fine bubble water against the particle-size adjusting sand and gravel by pump pressure. The behavior of sand and gravel due to jet collision causes a deviation in movement due to the difference in mass. This deviation causes more intense turbulent agitation than in the case of sand without gravel, enhancing the crushing effect. It is assumed that the particle size of the particle-size adjusting sand and gravel is about 1 mm to 3 mm. Also, in the case of paddy rice cultivation, the particle-size adjusting sand and gravel is made of particle-size adjusting steel slag.

[0023] In the method of generating the high-concentration FB water described above, the water flow moving at high speed in the section of the porous pipe reduces its pressure below atmospheric pressure. The gas to be sucked is restricted to FB with a diameter below a predetermined gas diameter during the ventilation process by the ventilation function of the porous structure (porosity, pore diameter) of the porous pipe and is taken into the water flow, ensuring a set amount of FB when the water flow passes through the porous pipe.

[0024] In the above method for producing high-concentration FB water, the device used in this method houses the porous pipe for producing FB water in a sealed gas pipe, and various gases encapsulated in FB are supplied to the sealed gas pipe at high pressure. In this method for producing FB water, the water flow moving at high speed through the section of the porous pipe reduces its pressure below atmospheric pressure. In addition to this, the high-pressure gas in the sealed gas pipe further expands the internal and external pressure difference across the entire length of the porous pipe. Moreover, the gas in the sealed gas pipe becomes FB with a diameter below a predetermined gas diameter restricted in the air permeation process due to the air permeation function of the porous structure (porosity, pore diameter) of the porous pipe, and is taken into the water flow. When the water flow passes through the porous pipe, it is characterized by ensuring a large set amount of FB. As described above, various high-pressure gases significantly increase the concentration of FB water, and the air permeation function of the porous pipe controls the bubble size.

[0025] In the above method for producing high-concentration FB water, the device used in this method consists of a water supply pressurizing pump, a porous pipe for producing FB water, a pressure boosting pump, a tank for producing UFB water, and a water supply pipe connecting these components. The tank for producing UFB water is filled with particle size-adjusting gravel, and the pipe connected to the tank has a nozzle at its tip. The water flow passing through the porous pipe takes in FB through the pores and becomes a fluid of high-concentration FB water. It is pressurized by the pressure boosting pump and jetted against the particle size-adjusting gravel in the tank for producing UFB water to liquefy the gas-water-particle size-adjusting gravel mass and cause collision and agitation. The method for producing high-concentration UFB water is characterized by further pulverizing high-concentration FB into ultra-fine particles by jet collision. The method for producing high-concentration UFB water goes through two stages of a production porous pipe and a production tank. This method is intended for paddy rice cultivation, and the particle size-adjusting gravel is changed to particle size-adjusting steel slag.

[0026] In the above method for producing high-concentration FB water, it is characterized by connecting porous pipes for producing FB water with different air permeability coefficients of the porous structure to simultaneously produce FB with different diameters.

[0027] The optimal bubble size varies depending on the application. Smaller bubbles aren't always better. Microbubbles (MB) and ultrafine bubbles (UFB) each have their own characteristics and advantages. Looking more closely, bubbles near the boundary between millibubbles and MBs, intermediate MBs, and bubbles near the boundary between MBs and UFBs also have similar characteristics. The basic differences lie in the amount of gas within the bubble and its lifespan. Larger diameter bubbles have a larger gas volume and a shorter lifespan. The opposite is true for smaller diameter bubbles. Combining bubbles of these diameters can double the effect. For example, this can be used to purify polluted water in rivers, dams, lakes, and reservoirs. The supply of oxygen promotes the decomposition of organic matter and pollutants in the water by microorganisms, preventing water quality deterioration. Even high-concentration UFB water today is still a negligible percentage. In water purification, in the short term, supplying oxygen with large-diameter bubbles promotes the decomposition of organic matter and pollutants by supplying large amounts of oxygen. In the long term, it is efficient to prevent water quality deterioration by continuously supplying oxygen with extremely small bubbles. Aeration with millibubbles is also effective. However, millibubbles have the disadvantage of quickly rising and dispersing into the atmosphere.

[0028] The apparatus used in the above-mentioned method for producing high-concentration FB water is characterized in that one section of the water supply hose of the water supply pipe is made into a porous hose, and the inner surface of this section is coated with a flexible porous material to form an FB generator. The apparatus used in this method for producing high-concentration FB water is intended for use in bathroom shower hoses, washing machine hoses, plant watering hoses, etc.

[0029] The apparatus used in the above-mentioned method for generating high-concentration FB water is characterized by installing a generating porous pipe upstream of the tap in the water supply pipe. This apparatus used in the method for generating high-concentration FB water is intended for use as an FB water dispenser in a kitchen. Effects of the invention

[0030] According to this invention, a porous pipe connected to a pressure pipe is compactly stored in a pressure tank either in a sealed gas pipe or in a coiled state, and various gases are supplied to these sealed gas pipes, etc., at high pressure. Water moves at high speed inside the porous pipe. As a result, a pressure drop occurs along the entire length of the porous pipe in proportion to the speed, and the pressure difference that allows gas to permeate into the pipe is further increased by the high-pressure gas. The size of the generated bubble diameter is controlled by the permeability coefficient of the porous structure (porosity, pore diameter) of the porous pipe. This makes it possible to realize a device that generates high-concentration fine bubbles of a set diameter or less while flowing water passes through the porous pipe. Various gases include air, oxygen, nitrogen, ozone, etc. [Brief explanation of the drawing]

[0031] [Figure 1] Plan view of a sealed gas pipe housing the porous pipe of the present invention [Figure 2] Similarly, the enlarged cross-sectional view of line AA in Figure 1. [Figure 3] Similarly, a vertical cross-sectional view of the UFB water generation tank. [Figure 4] Similarly, this schematic cross-sectional view shows the configuration of the FB water generator according to Embodiment 1. [Figure 5] Similarly, this schematic cross-sectional view shows the configuration of the FB water generator of Embodiment 2. [Modes for carrying out the invention]

[0032] The embodiments of the present invention will be described below with reference to Figures 1 to 5.

[0033] Figure 1 is a plan view of a sealed gas pipe housing the porous pipe of the present invention, and Figure 2 is an enlarged cross-sectional view of Figure 1 along line AA. In the figures, 1 is the porous pipe for generating FB water, 3 is the sealed gas pipe, and 7 is the pressure pipe or pressure hose. The porous pipe 1 is a fine bubble (FB) water generator. In the example shown in the figure, the porous pipe 1 connected to the pressure pipe 7 is housed in the sealed gas pipe 3. The structure of the porous pipe 1 is a continuous porous material with good permeability. Its thickness is approximately 2 mm to 5 mm. In terms of material, it has excellent abrasion resistance and impact resistance. Porous pipes 1 are prepared for each bubble passage diameter. For example, 1 μm, 10 μm, 25 μm, 50 μm, etc. Various gases are supplied to the sealed gas pipe 3 at high pressure.

[0034] Figure 3 is a vertical cross-sectional view of an ultrafine bubble (UFB) water generation tank. In the figure, 2 is the UFB water generation tank, 20 is the main tank, 21 is the lower tank, 22 is the porous plate, 23 is the sand jet nozzle, 10 is the automatic shut-off valve, and B is the particle size-adjusted sand and gravel. The UFB water generation tank 2 has a two-story structure separated into the main tank 20 and the lower tank 21 by the porous plate 22. The main tank 20 is filled with particle size-adjusted sand and gravel B. The particle size of this sand and gravel is about 1 mm to 3 mm, and the permeability coefficient is about 10 -4 The pressure is m / s. The porous plate 22 allows gas and water to pass through but does not allow the particle-size-adjusted sand and gravel B to pass through. The area of ​​the UFB water generation tank 2 and the water permeability (water permeability coefficient) of the particle-size-adjusted sand and gravel B are set to have sufficient water permeability relative to the water flow rate of the water supply pipe 7. The lower tank 21 has a water supply pipe 7 that sends out the UFB water.

[0035] Figure 4 is a schematic cross-sectional view illustrating the configuration of the fine bubble water generator of Embodiment 1. This Embodiment 1 is intended for purifying polluted water in rivers, dams, lakes, reservoirs, etc. In the figure, 8 is the water intake, 9 is the water discharger, and A is the raw water. The configuration of the apparatus used for generating high-concentration fine bubble water in Embodiment 1 consists of, from the upstream side, a water intake 8, a water supply pressurizing pump 4, a porous pipe 1 for generating FB water, a sealed gas pipe 3, various gas generators 6, a water discharger 9, and a pressure pipe or pressure hose 7 connecting them. The diameter of the porous pipe 1 is set as appropriate, for example, 60 mm. Compared to conventional nozzle-type FB generators, this is a large-diameter generator. Therefore, there is no concern whatsoever about clogging by sludge, foreign matter, etc. Also, the porosity of the porous pipe 1 allows gas to be drawn inward in one direction, and water flow containing foreign matter does not move from the inner surface to the outer surface of the porosity. Therefore, there is no clogging of the porosity and it is maintenance-free. Embodiment 1 is highly effective in purifying wastewater in conditions where algal blooms have occurred.

[0036] Figure 5 is a schematic cross-sectional view illustrating the configuration of the fine bubble water generator of Embodiment 2. This Embodiment 2 aims to achieve both improved productivity in paddy rice cultivation and climate change countermeasures by using particle-size-adjusted steel slag instead of particle-size-adjusted sand and gravel B, in addition to the UFB effect, by suppressing methane generation due to silica, lime, and iron oxide, and improving crop yields. The device in Patent Document 2 was filled with sandy material. This device uses particle-size-adjusted sand and gravel. The reason for this is that the porous pipe 1 already contains a high concentration of fine bubble water. This is further crushed into ultra-fine particles. The crushing method is the violent jet impact of fine bubble water onto the particle-size-adjusted sand and gravel using pump pressure. Due to the difference in mass, the behavior of the sand and gravel due to the jet impact causes a difference in movement. Unlike sand without gravel, this difference causes more violent turbulence and enhances the crushing effect. In addition, the permeability coefficient becomes significantly larger, making it easier to wash away any mixed fine particles during maintenance. The apparatus used in the method for generating high-concentration fine bubble water according to Embodiment 2 consists of, from upstream, a water intake 8, a water supply pressurizing pump 4, a porous pipe 1 for generating FB water, a sealed gas pipe 3, various gas generators 6, a pressure boosting pump 5, a UFB water generation tank 2, a water discharger 9, and a pressure pipe or pressure hose 7 connecting these. Embodiment 2 is highly effective in "achieving both improved productivity in paddy rice cultivation and measures against global warming."

[0037] The porous pipe 1 for generating FB water is a fine bubble water generator. By miniaturizing this and attaching it to a water supply system, the effective use of fine bubble water can be achieved. For example, it could be used in shower hoses in bathrooms, washing machine hoses, and watering hoses for plants. [Explanation of Symbols]

[0038] 1. Porous pipe for generating FB water 2 UFB water generation tanks 20 Main Tank 21 Lower tank 22 Porous version 23 Sand spray nozzle 3. Sealed gas pipe 4. Pressure pump 5. Booster pump 6. Various Gas Generators 7. Pressure pipe or pressure hose 8 Water intake 9 Water cannon 10 Automatic gate valve A. Raw water B Gravel size adjustment

Claims

1. An apparatus used for generating high-concentration fine bubble (FB) water, wherein the apparatus comprises a water supply pressurizing pump, an FB water generation porous pipe, and a water supply pipe connecting them, wherein the generation porous pipe creates a pressure difference along its entire length by using the suction force of gas into the pipe and the flow velocity of the water flow, and the size of the generated bubbles is limited by the permeability function of the porous structure (porosity, pore size) to a predetermined gas diameter or less, and is incorporated into the water flow as FB.

2. An apparatus for producing high-concentration FB water according to claim 1, characterized in that the porous pipe for producing FB water is housed in a sealed gas pipe, and various gases to be sealed in FB are supplied to the sealed gas pipe at high pressure, thereby increasing the supply of FB sealing gas and the pressure difference between the inside and outside of the entire length of the porous pipe with high-pressure gas.

3. An apparatus for producing high-concentration FB water according to claim 1, characterized in that the porous pipe for producing FB water is compactly stored in a pressure tank in a state of being wound multiple times, and various gases to be sealed in FB are supplied to the pressure tank at high pressure, thereby increasing the supply of FB sealing gas and the pressure difference between the inside and outside of the entire length of the porous pipe with high-pressure gas.

4. An apparatus for producing high-concentration FB water according to claim 1, wherein the apparatus comprises a water supply pressurizing pump, an FB water generation porous pipe, a pressure boosting pump, an ultrafine bubble (UFB) water generation tank, and a water supply pipe connecting these, wherein the UFB water generation tank is filled with particle size-adjusted sand and gravel, the tip of the pipe connected to the tank is narrowed to form a nozzle, and a mixed fluid of high-concentration FB and water is jetted and impacts the particle size-adjusted sand and gravel, and the generation of ultrafine gas is carried out in two stages, in the generation porous pipe and the generation tank.

5. A method for producing high-concentration FB water according to claim 1, characterized in that the water flow moving at high speed through the section of the porous pipe reduces its pressure to below atmospheric pressure, the aspirated gas becomes FB with a predetermined gas diameter or less that is limited in the permeation process by the permeability function of the porous structure (porosity, pore size) of the porous pipe, and a set amount of FB is secured when the water flow passes through the porous pipe.

6. A method for producing high-concentration FB water according to claim 1, wherein the apparatus used in the method houses an FB water production porous pipe in a sealed gas pipe, and various gases to be sealed in FB are supplied to the sealed gas pipe at high pressure, and in the method of producing FB water, the water flow moving at high speed through the section of the porous pipe reduces its pressure to below atmospheric pressure, and in addition, the high-pressure gas in the sealed gas pipe further increases the pressure difference between the inside and outside of the entire length of the porous pipe, and the gas in the sealed gas pipe is incorporated into the water flow as FB with a predetermined gas diameter or less, which is limited in the permeability process by the permeability function of the porous structure (porosity, pore diameter) of the porous pipe, and a large set amount of FB is secured when the water flow passes through the porous pipe.

7. Claim 1: A method for producing high-concentration FB water, wherein the apparatus used in the method comprises a water supply pressurizing pump, an FB water production porous pipe, a pressure boosting pump, a UFB water production tank, and a water supply pipe connecting them, the UFB water production tank is filled with graded sand and gravel, the water supply pipe connected to the tank has a nozzle at its tip, the water flow passing through the porous pipe takes in FB through the pores and becomes a high-concentration FB water fluid, this fluid is pressurized by the pressure boosting pump and jetted onto the graded sand and gravel in the UFB water production tank, thereby liquefying the gas, water, and graded sand and gravel and causing collisional turbulence and agitation, the method for producing high-concentration UFB water characterized by further crushing the high-concentration FB into ultrafine particles.

8. A method for producing high-concentration FB water according to claim 1, characterized in that FB water production porous pipes with different permeability coefficients are connected to simultaneously produce FB of different diameters.

9. An apparatus for producing high-concentration FB water according to claim 1, characterized in that one section of the water supply hose of the water supply pipe is made into a porous hose, and the inner surface of this section is coated with a flexible porous material to form an FB generator.

10. An apparatus for producing high-concentration FB water according to claim 1, characterized in that a generating porous pipe is installed upstream of the tap of a water supply pipe.

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