JP5000583B2 - Micro / nano bubble generation method and apparatus, and micro / nano bubble water generation apparatus - Google Patents

Description

The present invention relates to a micro / nano bubble generation method and apparatus used in an apparatus for generating micro / nano bubble water, and a structure of a micro / nano bubble water generation apparatus , and more particularly, a peak of bubble distribution when micro bubbles are generated even in fresh water. The present invention relates to a structure capable of simplifying the apparatus while having a high concentration of about 10 μm.

There are a shearing method, a pressurizing method, and the like for the refinement of bubbles, but in order to stably send out the refined bubbles, it is necessary to slow down the disappearance time of each of the bubbles without fusing them again. In water containing electrolyte ions such as sea water, the ionic charge is taken into the surface of the bubble and the bubbles themselves are charged and the bubbles repel each other to prevent fusion and to form an ion shell by charge concentration when the bubbles contract. Although fine stabilization becomes relatively easy, since such a phenomenon is small in fresh water with few ions, stable generation of microbubbles becomes difficult. Therefore, in order to generate microbubbles in fresh water, the conventional method uses a pressurization pump to send water and gas into a pipe set with physical obstacles, and forcibly injects the microbubbles. The generation of bubbles has become the mainstream. The main prior art referred to is described below.
Japanese Patent No. 3043315 Japanese Patent Laid-Open No. 2001-300522 JP 2004-073953 A JP 2005-245817 A

  In the above method, it is necessary to generate excessive pressure in the generated piping, and since it becomes a complicated structure due to high output of the pump and setting of physical obstacles in the piping, it is not a simple device, but a practical level It has not reached. The present invention provides an apparatus and a method that enable the generation of micro / nano bubbles more simply.

As described above, it is difficult to stabilize the bubbles finely in fresh water because there are few ions and the surface of the bubbles is less charged. In the present invention, focusing on the fact that microbubbles that produce the same effect as the state of being charged to ionic charges are generated by charging static electricity on the surface of the bubbles by high-speed friction between the bubbles. to produce a pipe of the double pipe structure the inner pipe was set boss, set the helical grooves in each tube and the opposite direction respectively turning direction of the outer tube within tube, bubbles together by impinging water flowing Friction at high speed. Thereby, static electricity is charged on the bubble surface to generate microbubbles.

That is, the present invention includes two types of pipes having predetermined lengths with different opening diameters arranged inside and outside, and has a double structure pipe of an outer pipe and an inner pipe, and is in close contact with the inner surface of each pipe. A spiral member is arranged in a different direction to form a spiral member, and has a cavity communicating in the axial direction of the inner tube inside the spiral member in close contact with the inner surface of the inner tube. A micro-bubble generating part is formed by forming a spiral groove composed of an inner surface and each of the spiral members, and when the spiral water flow including bubbles of different directions flowing along the spiral groove is discharged at the same time, This is a method of generating micro / nano bubbles by friction and shearing.
Further, the present invention comprises a pipe of double structure of the outer tube and the inner tube by placing the two types of tubes with different predetermined lengths opening diameters inside and outside, in close contact with the inner surface of the front Stories each tube The linear members are spirally arranged in different directions to form a spiral member, and the inside of the spiral member in close contact with the inner surface of the inner tube has a cavity communicating in the axial direction of the inner tube. A microbubble generator having a spiral groove formed of an inner surface of the tube and each of the spiral members is formed, and collides when a spiral water flow including bubbles of different directions flowing along the spiral groove is simultaneously released. It is a micro / nano bubble generating device characterized by being made.
In addition, the micro / nano bubble water generator of the present invention is based on the above idea, and creates a double tube structure pipe (diameter ratio 2: 1) of an outer tube and an inner tube, and sets a spiral groove in each tube to form an outer tube. The above-mentioned micro / nano bubble generating device including a micro bubble generating unit in which the swirling directions of the tube and the inner tube are reversed is prepared. Then, the gas suction ejector, the circulation pump, and the two microbubble generating units of the micro / nano bubble generating device are connected by piping in the order of description. Microbubbles are generated by the operation of the circulation pump, and when the gas suction ejector provided in the water suction pipe on the pump suction side sucks in the gas due to the generation of negative pressure due to the passage of the water flow, millimeters of bubbles are generated from the pump discharge side. A water stream is discharged. The water stream containing bubbles is sent to the micro-bubble generation part (double pipe structure part) through the pipe, where the water stream is divided into an outer pipe side spiral groove and an inner pipe side spiral groove and flows along each groove. become. Each water flow flows while rotating at a high speed in the spiral groove, and since a strong centrifugal force is applied to the contained bubbles, they are rapidly compressed and miniaturized. The bubbles contained in the water flow discharged from each tube groove are reduced in pressure by centrifugal force (centrifugal force F = mass m × velocity v2 / swivel radius r) proportional to the swirl diameter, and the outer tube diameter: inner tube diameter. By setting = 2: 1, the bubble diameter also becomes the bubble diameter in the outer tube: the bubble diameter in the inner tube = 2: 1. When air bubbles are mixed violently due to the difference in swirl direction in the opening portion, the bubbles in each tube collide so that the small bubbles in the inner tube shear the large bubbles in the outer tube. At this time, friction occurs, and the bubbles are charged with static electricity.

  After each bubble is charged with a negative charge due to static electricity, each bubble can exist as a microbubble due to the repulsion of the same charge. The generated microbubbles are crushed by the self-pressurization effect due to the surface tension at the gas-liquid interface, but at the same time the charge density of negative charges charged on the bubble surface also increases, so the electrolyte ions are concentrated The same action as the “ion shell” that occurs in some cases occurs and can be stabilized as micro / nano bubbles even in fresh water with few ions.

  Pump piping was circulated through the water tank and two microbubble generators were installed on the discharge water flow side. Gas is sucked from the suction side through the gas suction ejector, and a water flow containing bubbles is discharged from the pump. When the water flow passes through the first microbubble generator, the bubbles are dispersed and refined, and then pass through the second microbubble generator to further refine the micro-nano bubbles. Sure.

This onset Ming, since the conventional structure makes the bubble generation to be mixed under pressure by using a physical obstacle to the generation of vortices from the screw shape, for performing the same tube a rectifier or dispersion from the occurrence of vortex In contrast to the pipe-integrated type consisting of a continuous structure, bubbles are refined by high-speed mixed flow of two water streams released from the spiral swivel part, so only the microbubble generating part is installed locally in the pipe This makes it possible to generate bubbles. This makes it possible to simplify the piping design because it can be installed locally in a pipe with a discharge water flow. In addition, the obstacle in the pipe, which is a requirement for pressure generation, is spiraled in this structure because the obstacle area is smaller than in the conventional structure. Since only the groove reduces the pressure in the pipe, it can be operated even with a low-pressure pump, and the entire apparatus can be simplified and power can be saved. In addition, the amount of gas suction is large and stable due to a decrease in exhaust pressure.

Generator of micro-nano bubble water of the present invention the gas is sucked by utilizing the water flow by one pump, to generate microbubbles thereby mixed flow produces two high-speed swirling flow by the working pipe, until Na Nobaburu product In the pipe of the water discharge side water flow.

Example 1
In the same pipe, which is a feature of the present invention, a pipe having a double pipe structure of an outer pipe and an inner pipe set at a caliber ratio of 2: 1 is prepared, and a spiral groove is set in each pipe to set the outer pipe side and the inner pipe side. The parts where the turning directions are opposite to each other will be described with reference to FIG. FIG. 1 is an exploded perspective view showing an embodiment of a micro / nano bubble generating apparatus including a micro bubble generating unit 1, (a) FIG. 1 shows an inner tube spiral portion, and (d) FIG. 1 shows an outer tube spiral portion. . The inner pipe 2 is a metal or resin pipe having an outer diameter of 18 mm and an inner diameter of 13 mm, and the spiral member 3 is made of metal or resin, and a 3.5 mm × 3.5 mm square wire is swung clockwise with a pitch P of 15 mm. The length is 110 mm, the outer diameter is controlled to 13 mm, and the inner tube is fitted. The length of the inner tube was set to 110 mm. The shape of the end of the spiral member 3 at the end of the inner tube is as follows: when the rectangular wire is cut parallel to the axis of the inner tube as shown in FIG. Sometimes shearing parallel to the end face of the tube. These shapes are not particularly limited, but are caused by the manufacturing means. When the length of the inner tube is cut to a predetermined length after the helical member 3 is fitted into the inner tube 2, the above-mentioned (b) It becomes the shape of the figure. As a means for fixing the spiral member 3 to the inside of the inner tube 2, a method of integrally forming a spiral groove on the outer peripheral surface and the inner peripheral surface of the inner tube by welding, ultrasonic welding, and stereolithography can be used.

A spiral member 4 is formed on the outer peripheral surface of the inner tube 2 using the rectangular wire as shown in FIG. The spiral turning direction is counterclockwise, and the pitch P is also set to 15 mm. As in the case described above, the end shape of the spiral member may be parallel to the end surface of the inner tube (e) or may be cut parallel to the inner tube axis (d). After fixing the spiral member 4 to the peripheral surface of the inner tube 2, the inner tube 2 is fitted into the outer tube 5. The inner diameter of the outer tube 5 is 25 mm, and the outer tube 5 is finished with a tolerance such that the outer diameter of the spiral member 4 is inserted. Although the outer diameter of the outer tube 5 are determined in accordance with the pipe specifications for use in piping generator of micro-nano bubble water of the present invention described below, the outer tube 5 full length of the inner tube the full length i.e. the helical member 3 and 4 A bubble collision section, which will be described later, may be set by making it 40 mm longer than the length. The rectangular wire has a square cross-sectional shape, but is not limited thereto, and other polygonal or circular wires can be used.

In FIG. 1, when the inner tube 2, the inner tube side spiral member 3 and the outer tube side spiral member 4 are inserted into the outer tube 5, a spiral groove 6 surrounded by each spiral member and the side surface of the tube is formed. When the water flow is passed in the direction of the circulating water flow, the water flow is divided into two flows, and the spiral water flow 7 shown in FIG. 1 (c) is turned clockwise on the inner tube side, and the left turn shown in FIG. The spiral water flow 8 is generated. The swirl direction of the water flow is not limited to the above-described direction as long as the outer tube side and the inner tube side are opposite directions. The spiral water flows on the inner tube side and the outer tube side that have passed through the spiral groove are discharged from the spiral groove, collide with each other as shown in FIG. 2, and are mixed and discharged from the outer tube as a mixed flow discharge water flow. In this embodiment, the outer pipe 5 is a spiral water flow section having a length of 110 mm between the lengths L1 , and the section L2 is a spiral flow collision section. L2 is preferably set to about 40 mm.

In the outer tube spiral portion, an inner diameter of 25 mm, a spiral groove of 3.5 mm × 11.5 mm is set to a tube length of 110 mm with a pitch of 15 mm , and the outer tube water flow flows along this while rotating at high speed. In the inner pipe spiral portion, an inner diameter of 13 mm and a spiral groove of 3.5 mm × 11.5 mm are set to a pipe length of 110 mm at a pitch of 15 mm, and the inner pipe water flow flows while swirling at a high speed. A hollow portion having a diameter of 6 mm is generated in the inner tube central portion, and has an effect of reducing the pressure in the tube and preventing clogging of foreign matters. As will be described later, the bubbles contained in each water flow are compressed in the groove due to the centrifugal force due to each swirl flow, but rapidly shrink, but the ratio of the inner diameter of the outer tube and the inner tube is 2: 1 and the centrifugal force is different, so the compression is The bubble diameter at that time is a ratio of outer tube: inner tube = 2: 1. The bubbles before swirling are uniformly dispersed by the orifices described later, and the bubble diameters are almost the same both inside and outside. However, due to the compression described above, the bubbles in the outer tube and the inner tube are different in diameter. The bubbles in the tube have different internal pressures and different surface tensions on the bubble surface. If bubbles of the same diameter and pressure collide, they will repel if they are fused or charged, but bubbles that have a large diameter and low internal pressure will collide with bubbles that have a small diameter and high internal pressure. If so, large bubbles are sheared. Further, when sheared, friction occurs between the bubbles, and static electricity is generated in each bubble to be charged. In this case, since the bubbles are negatively charged, the bubbles repel each other to form microbubbles.

(Example 2)
It will be described with reference to FIG. 3 for the entire configuration of the generation device 10 of the micro-nano bubble water used in the present invention. The apparatus comprises a water tank 11 and a circulation part 12 for circulating water, and the circulation part 12 constitutes an ejector 13 for sucking gas into the water flow, a circulation pump 14 for generating the water flow, and two micro / nano bubble generation devices. 1 microbubble generating part 1a and 2nd microbubble generating part 1b are provided, and it comprises pipe part 15 which connects these. The water flow is generated in the direction of the arrow in the figure. Pump piping ( 25 A, inner diameter 25 mm ) is circulated through the water tank 11, and an ejector 13 for sucking gas is installed on the suction side. Although the details are omitted, an air introduction pipe is arranged in the water flow by pump suction, a negative pressure is generated in the pipe, and the gas is sucked and mixed in water. Water mixed with gas from the pump discharge side is pumped to the first microbubble generator 1a. However , the gas is mixed in water in the pipe, and the bubbles are not uniformly distributed. As described above, since it is desirable for the microbubble generators 1a and 1b to pass a water flow containing bubbles uniformly through the outer tube and the inner tube, an orifice 16 having a diameter of 8.7 mm is provided in the tube in front of the microbubble generator 1a. Immediately after the water flow was collected, the water flow was bent by 90 degrees using an elbow 17a in the pipe, thereby drawing out the rectification effect and making the dispersion of bubbles uniform. When the water flow containing bubbles passes through the microbubble generator 1a, the water flow is divided into two flows, the outer tube spiral portion and the inner tube spiral portion described above, and these water flows collide to generate microbubbles. As a bubble collision section, a length of 40 mm is required with the inner diameter of the outer tube being 25 mm from the end of the spiral groove of each tube.

Above is set becomes the process of microbubble generating section 1a, a microbubble generation section 1b of similar structure to the generated microbubbles and Ma Micro-nano bubble in the pipe behind. However, since the water flow that has passed through the microbubble generator 1a is in a mixed state, it is necessary to rectify in order to uniformly introduce bubbles into the microbubble generator 1b, so that an elbow 17b is used in the piping behind the microbubble generator 1a. The water flow is bent 90 degrees to rectify the water flow. The flow of water containing the rectified microbubbles passes through the microbubble generator 1b in the same process as described above, and further repeats charging by compression, shearing, and friction, and the microbubbles are further refined to form micro / nano bubbles in the water. To be released. The generated microbubbles are crushed by the self-pressurization effect due to the surface tension at the gas-liquid interface, but at the same time the charge density of negative charges charged on the bubble surface also increases, so the electrolyte ions are concentrated The same action as the “ion shell” that occurs in some cases occurs and can be stably maintained as micro / nano bubbles even in fresh water with few ions.

(Verification of micro / nano bubble generation)
(1) Regarding bubble miniaturization due to differences in water flow, the technology of other companies performs bubble miniaturization due to physical obstacles in the pipe, so the area of the obstacle is large and the pressure in the pipe rises, so the inside of the pipe is about 0.4MP However, this structure is not an obstacle but a pipe structure for water flow guidance, so the obstacle area is reduced and the pressure in the pipe is suppressed to about 0.2MP. Therefore, it can be confirmed that microbubbles are generated not by physical obstacles but by structural water flow effects. When the obstacle area is reduced to a pressure of about 0.2 MP, microbubbles are not generated in the conventional structure. This is because in the conventional structure, the refinement of bubbles depends on the effect of physical obstacles, and it has been proved that the refinement efficiency decreases if the obstacle area is reduced.

  (2) Regarding charging due to friction between bubbles, friction occurs when bubbles collide with each other to charge static electricity. Therefore, the potential in water becomes negative due to the presence of negative charges due to static electricity. In the ph measurement of the treated water according to the present invention, since there was a potential difference as a reaction condition of the reagent, an alkaline reaction was shown, and the presence of a negative charge was confirmed.

(3) About generation | occurrence | production of micro / nano bubble, when the treated water was produced | generated with the apparatus of this structure, although it is visual, it has become cloudy. The treated water that became clouded after a few minutes after the stop of the device returned to a transparent state, but when treated again, it was confirmed that it became clouded in a shorter time than the first treatment time. This phenomenon can be confirmed until about 48 hours have elapsed after the treatment, so that the presence of micro / nano bubbles at a level that cannot be visually observed in the treated water is clear.

  Since fine bubbles can be supplied in a high concentration in the liquid, it can greatly contribute to water quality improvement by supplying oxygen. Although the embodiment described above mainly describes bubbles containing air, it is possible to supply bubbles using a gas such as oxygen or ozone instead of air, and in recent years dioxins contained in water, sludge, and slurry. In addition, research using fine bubbles as a means for decomposing persistent organic substances such as agricultural chemicals is underway. Many uses can be expected as means for obtaining fine bubbles with a simple structure.

It is a disassembled perspective view of the microbubble generation | occurrence | production part of this invention (Example 1). It is a perspective view which shows a mode that two systems of spiral water flow collide (Example 1). (Example 2) which is a structure explanatory drawing of the micro nano bubble water production | generation apparatus of this invention.

DESCRIPTION OF SYMBOLS 1 Micro bubble generation | occurrence | production part 2 Inner pipe | tube 3 Spiral member 4 Spiral member 5 Outer pipe 6 Spiral groove 7 Spiral water flow 8 Spiral water flow 10 Micro / nano bubble water generator 11 Water tank 13 Gas suction ejector 14 Circulation pump 15 Piping part 16 Orifice

Claims (6)

Two types of pipes having predetermined lengths with different opening diameters are arranged inside and outside to provide a double-structured pipe of an outer pipe and an inner pipe, and the linear members are in close contact with the inner surfaces of the pipes in different directions. A spiral member arranged in a spiral form, having a cavity communicating in the axial direction of the inner tube inside the spiral member in close contact with the inner surface of the inner tube, and the inner surface of each tube and each of the spiral members A micro-bubble generating part is formed by forming a spiral groove made of and colliding when a spiral water flow including bubbles of different directions flowing along the spiral groove is discharged at the same time, and friction and shearing are performed on the bubbles. -A method of generating nanobubbles.   2. The method of generating micro / nano bubbles according to claim 1, wherein the winding pitches of the spiral members arranged in the outer tube and the inner tube are set to the same length. Comprising a pipe having a double structure of the outer tube and the inner tube two kinds of tubes having different predetermined lengths opening diameters arranged inside and outside, before Symbol closely to the inner surface of each tube is a linear member different from each other A spiral member arranged in a spiral direction, and having a cavity communicating with the inner tube in the axial direction inside the spiral member in close contact with the inner surface of the inner tube; A microbubble generator having a spiral groove formed of a spiral member is formed, and the spiral water flow including bubbles having different directions flowing along the spiral groove is collided when discharged simultaneously. Micro / nano bubble generator.   A gas suction ejector, a circulation pump, and the two microbubble generators of the micro / nanobubble generation device according to claim 3 are connected by piping in the order of description, and water is sucked into the gas suction ejector by the operation of the circulation pump. And generating bubbles in the sucked water, and then dispersing the sucked bubbles in the discharge-side piping of the circulation pump so that at least two microbubble generators pass through the micro / nano bubble water. apparatus.   The apparatus for generating micro / nano bubble water according to claim 4, wherein an orifice is provided in a discharge-side pipe of the circulation pump, and bubbles sucked by passing through the orifice are dispersed.   6. The micro / nano bubble water according to claim 4 or 5, wherein pipes on the inflow side of the two micro / nano bubble generation devices are elbows, the water flow is bent and rectified, and the micro bubble generation unit is allowed to pass through. Generator.