JP2013107060A - Nanobubble generator - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a nanobubble generator capable of easily controlling nanobubble generating conditions and the diameter of nanobubbles.SOLUTION: The nanobubble generator 1 includes a booster pump 40 pressurizing water and gas supplied into a passage, to a first pressure and delivering pressurized mixed water in which water and gas are mixed, into the passage; a pressurized dissolution water holding chamber 50 maintaining the pressurized mixed water to the first pressure and holding the pressurized dissolution water in which gas is dissolved in water; a reduced pressure chamber 60 reducing the pressurized dissolution water to a second pressure lower than the first pressure; a rotating shaft body 70 arranged to penetrate the pressurized dissolution water holding chamber 50 and an opening 51 and to reach the inside of the reduced pressure chamber 60; a rotating blade body 71 mounted to the tip of the rotating shaft body 70, arranged in the reduced pressure chamber 60 and formed in shape of a line worm; a motor 72 for rotating the rotating shaft body 70; and a discharge pipeline 80 for discharging water and gas from the reduced pressure chamber 60.

Description

  The present invention relates to a nanobubble generator that generates nanobubbles as fine bubbles.

  Conventionally, nanobubbles, that is, water containing a large amount of bubbles having a diameter of 1 μm (1000 nm) or less, promotes sterilization and deodorization effects, physiological activities of organisms, and has a metabolic function compared to water not containing nanobubbles. It is known that the effect of increasing is higher. If the water containing nanobubbles is used as gargle water, for example, the mouth can be sterilized. In addition, for example, if nanobubbles are formed by ozone, the effects of sterilization and deodorization can be further enhanced. On the other hand, if nanobubbles are formed by oxygen, the growth of plants can be promoted by using water containing nanobubbles for hydroponics. This is thought to be because the oxygen in the nanobubble state is more easily absorbed by the plants that are hydroponically cultivated than the oxygen dissolved in the water.

  Nanobubbles having such characteristics may be generated when microbubbles of several μm to several tens of μm continue to shrink in water and collapse. However, such naturally generated nanobubbles disappear in a short time, and the generation amount is small, which is not practical.

  On the other hand, nanobubbles are known to be retained without disappearing for a long period of time by forcibly generating fine bubbles in water containing electrolyte ions. When nanobubbles are generated by forcibly crushing microbubbles in water containing electrolyte ions, the bubble interface of nanobubbles is negatively charged. Each nanobubble that is negatively charged in water repels each other. In addition, electrolyte ions at the bubble interface of the nanobubble serve as a shell. Therefore, nanobubbles generated in water containing electrolyte ions are difficult to disappear.

  For example, in Japanese Patent No. 4144669 (hereinafter referred to as Patent Document 1), fine bubbles are mixed in an aqueous solution in a container, and then electrolyte ions are mixed into the aqueous solution. A method for producing nanobubbles by applying shock waves or ultrasonic waves as physical stimuli is described. In addition, after mixing fine bubbles with the aqueous solution in the container, the rotating body attached in the container is rotated at 500 to 10,000 rpm to cause the aqueous solution to flow, and the compression, expansion and vortex generated during the flow are used as physical stimuli. A method for producing nanobubbles by adding is described.

  Further, for example, Japanese Patent No. 4430609 (hereinafter referred to as Patent Document 2) describes a nanobubble generator using a bladed rotating body as bubble crushing means for generating nanobubbles by crushing microbubbles. .

  Furthermore, for example, in Japanese Patent Application Laid-Open No. 2002-85949 (hereinafter referred to as Patent Document 3), a swirl force and a centrifugal force are applied to a gas-liquid mixture by a screw portion having a spiral blade to create a swirl flow. An ultra-fine bubble generating device is described that continuously generates ultra-fine bubbles of about 0.5 to 3.0 μm when a flow collides with protrusions of a cutter part.

  Furthermore, for example, JP-A-8-103778 (hereinafter referred to as Patent Document 4) describes that ultrafine bubbles are generated by a vortex and a shearing force of a blade.

Japanese Patent No. 4144669 Japanese Patent No. 4430609 JP 2002-85949 A JP-A-8-103778

  In the method or apparatus described in Patent Documents 1 to 4, nanobubbles are generated by applying vortex flow, crushing, centrifugal force, shearing force, and the like as physical stimuli to the fine bubble mixture. However, in these methods or apparatuses, even if nanobubbles can be generated, there is a problem that it is difficult to control the nanobubble generation conditions and the nanobubble diameter.

  Therefore, an object of the present invention is to provide a nanobubble generator capable of easily controlling the nanobubble generation conditions and the nanobubble diameter.

  The nanobubble generator of the present invention includes a flow path, a pressurized mixed water supply unit, a pressurized dissolved water holding chamber, a decompression chamber, a rotating shaft body, a rotating blade body, a motor, and a discharge pipe. Prepare. Water and gas flow through the channel. The pressurized mixed water supply unit is disposed in the flow path, pressurizes the water and gas supplied in the flow path to a first pressure, and mixes the pressurized mixed water in which the water and the gas are mixed in the flow path. To send. The pressure-dissolved water holding chamber is disposed in the flow path and maintains the pressure-mixed water in which the gas is dissolved in water while maintaining the pressure-mixed water at the first pressure. The decompression chamber decompresses the pressurized dissolved water to a second pressure lower than the first pressure. The pressurized dissolved water holding chamber and the decompression chamber are connected by an opening having a diameter capable of passing the pressurized dissolved water. The rotating shaft body is disposed so as to pass through the pressurized dissolved water holding chamber and the opening and reach the decompression chamber. The rotating blade body is attached to the tip of the rotating shaft body and is disposed in the decompression chamber, and has a single worm shape. The motor rotates the rotating shaft. The discharge pipe discharges water and gas from the decompression chamber.

  By rotating the rotating shaft body, the pressurized dissolved water is decompressed and ejected from the pressurized dissolved water holding chamber toward the decompressed chamber through the opening. The rotational speed of the motor is variable.

  In the nanobubble generator of the present invention configured as described above, the pressurized dissolved water held in the pressurized dissolved water holding chamber is sent into the decompression chamber through the opening by the rotation of the rotary blade body. At this time, cavitation occurs due to rapid decompression, microbubbles are generated as fine bubbles, and are ejected into the decompression chamber.

  Further, by increasing the rotation speed of the rotary blade body, the ejection speed in the decompression chamber from the pressurized dissolved water holding chamber can be increased. At this time, the pressure in the decompression chamber is further reduced to a negative pressure. For this reason, nanobubbles having a diameter of 1 μm or less are generated as finer bubbles for more rapid decompression, and are ejected into the decompression chamber.

  Therefore, in the nanobubble generator of the present invention, the negative pressure in the decompression chamber can be controlled by changing the rotational speed of the rotating blade body, that is, the rotational speed of the motor, so the diameter of the generated bubble is controlled. It becomes possible. In other words, the conditions for generating nanobubbles and the diameter of nanobubbles can be easily controlled simply by changing the rotational speed of the motor.

  As described above, according to the present invention, it is possible to provide a nanobubble generator capable of easily controlling the conditions for generating nanobubbles and the diameter of nanobubbles.

It is a figure showing typically the whole nano bubble generating device as one embodiment of the present invention. It is sectional drawing which shows the cross section of the II-II line of FIG.

  Hereinafter, an embodiment of the present invention will be described with reference to the drawings.

  As shown in FIG. 1, the nanobubble generator 1 includes a water storage tank 10 as a water storage unit that stores water 200 containing electrolyte ions, an ozone generator 20, a gas intake amount adjustment valve 30 as a gas supply unit, and pressurization. A pressure pump 40, a pressure-dissolved water holding chamber 50, a decompression chamber 60, and a discharge conduit 80 are provided as a mixed water supply unit. The pressurizing pump 40, the pressurized dissolved water holding chamber 50, and the decompression chamber 60 are arranged in a flow path through which water and gas flow and are connected in series.

  As the pressurizing pump 40, for example, a diaphragm type liquid pump is used. Since the diaphragm type pump delivers water 200 and gas by volume expansion and contraction pressure feeding, there is no rotational friction portion in the flow path. For this reason, it is possible to reduce the clogging of the operating part as compared with the case where other pumps are used. The pressurizing pump 40 promotes the dissolution of the water 200 and the gas by the volume pressure in the diaphragm. In other vanes, gear pumps, etc., extrusion pressure is generated after the discharge port, so a separate dissolution tank is required.

  An intake pipe 101 having an intake port 11 is connected to the pressurizing pump 40 as a flow path. The water intake 11 of the water intake pipe 101 is disposed in the water 200 stored in the water storage tank 10. In the water 200, sodium, sodium chloride, potassium, calcium, magnesium, and other minerals are dissolved as an electrolyte. These electrolytes become electrolyte ions by being dissolved in water. In addition, it is not always necessary to include electrolyte ions in the water 200 used in the nanobubble generator 1 of the present invention.

  The gas intake amount adjustment valve 30 is disposed in the intake pipe 101 between the intake port 11 and the pressurizing pump 40. The gas intake amount adjustment valve 30 is connected to an ozone generator 20 having an air inlet 21. By opening and closing the gas intake amount adjustment valve 30, the amount of gas taken into the intake pipe 101 from the air inlet 21 through the ozone generator 20 is adjusted. The ozone generator 20 generates ozone by plasma silent discharge using air sucked from the air suction port 21 as a raw material. The gas intake amount adjustment valve 30 functions as an intake port that naturally inhales ozone into the flow path and dissolves it in the water 200. Note that the gas used in the nanobubble generator 1 of the present invention does not necessarily include ozone.

  The pressurizing pump 40 is connected to the pressurized dissolved water holding chamber 50 through the water supply pipe 102. The pressurizing pump 40 pressurizes the water and gas supplied to the intake pipe 101 as a flow path to a first pressure, for example, a pressure of about 0.3 MPa (about 3 atmospheres), and the water and gas The pressurized mixed water mixed with is sent out to the water supply pipe 102 as a flow path. The pressure-dissolved water holding chamber 50 has a substantially cylindrical space, and the pressure-dissolved water in which gas is dissolved in water by maintaining the pressure-mixed water sent from the water supply pipe 102 at the first pressure. Hold.

  The pressurized dissolved water holding chamber 50 is connected to the decompression chamber 60 through the opening 51. The decompression chamber 60 has a substantially cylindrical space, and the pressurized dissolved water supplied from the pressurized dissolved water holding chamber 50 through the opening 51 is supplied to a second pressure lower than the first pressure, for example, normally Depressurize to about 1 atmosphere. The opening 51 is disposed between the pressurized dissolved water holding chamber 50 and the decompression chamber 60 and has a diameter that allows the pressurized dissolved water to pass therethrough.

  The rotating shaft 70 is disposed so as to penetrate the pressurized dissolved water holding chamber 50 and the opening 51 and reach the decompression chamber 60. For this reason, as shown in FIG. 2, the opening 51 is formed as a gap having an annular cross section.

  A motor 72 is connected to the end of the rotating shaft body 70 on the pressurized dissolved water holding chamber 50 side through a shaft coupling 73. The rotating shaft 70 is rotated by the motor 72. The rotation speed of the motor 72 is variable. For example, the rotational speed of the motor 72 is 0 to 2500 r. p. m. It is variable within the range. A bearing 74 that supports the rotating shaft body 70 is provided between the shaft coupling 73 and the pressurized dissolved water holding chamber 50.

  A single worm-shaped rotary blade body 71 is attached to the end (tip) of the rotary shaft 70 on the decompression chamber 60 side. The rotary blade 71 is disposed in the decompression chamber 60 and is rotated by a motor 72.

  A discharge conduit 80 is connected to the decompression chamber 60 as a flow path. Water and gas are discharged from the decompression chamber 60 through the discharge pipe 80.

  Since it is configured as described above, when the rotating shaft 70 is rotated, the pressurized dissolved water is decompressed and ejected from the pressurized dissolved water holding chamber 50 toward the reduced pressure chamber 60 through the opening 51.

  The intake pipe 101, the water supply pipe 102, and the discharge pipe line 80 are examples of flow paths.

  Next, generation of nanobubbles by the nanobubble generator 1 will be described.

  When the pressure pump 40 of the nanobubble generator 1 is driven, the water 200 stored in the water storage tank 10 flows into the water intake pipe 101 from the water intake 11. Gas is supplied from the outside of the intake pipe 101 to the water 200 flowing through the intake pipe 101 through the gas intake adjustment valve 30. The gas intake amount adjustment valve 30 takes in gas from the air inlet 21 of the ozone generator 20 with negative water pressure. The air passing through the ozone generator 20 contains ozone by silent discharge, for example. In this embodiment, for example, 50 to 150 mg of ozone is generated per hour by plasma silent discharge, and the generation concentration of ozone in the air is set to 30 to 80 ppm (15 L / min). The gas intake amount adjustment valve 30 is finely adjusted to open and close so as to balance the pumped water amount of the pressurizing pump 40 and the gas intake amount. The gas taken into the intake pipe 101 becomes a relatively large large bubble 201 and flows through the intake pipe 101 together with the water 200 toward the pressurizing pump 40.

  The large bubbles 201 and the water 200 taken into the water intake pipe 101 by the gas intake amount adjusting valve 30 are pressurized by the pressurizing pump 40 and mixed. At this time, the large bubbles 201 are dissolved in the water 200 to some extent. The water 200 and gas pressurized by the pressure pump 40 flow into the water supply pipe 102. Within the pressurizing pump 40, the water 200 is pressurized to the first pressure. In this embodiment, the first pressure is about 0.3 MPa.

  Large bubbles 201 are dispersed in the water 200 in the water pipe 102. The water 200 including the large bubbles 201 flows into the pressurized dissolved water holding chamber 50 through the water supply pipe 103. In the pressurized dissolved water holding chamber 50, the pressurized dissolved water in which the large bubbles 201 are dissolved in the water 200 is held by maintaining the pressurized mixed water at the first pressure. The inner diameter of the water supply pipe 103 at a location connected to the pressurized dissolved water holding chamber 50 is, for example, about 8 mm. The cylindrical inner diameter of the pressurized dissolved water holding chamber 50 is, for example, about 15 mm.

A decompression chamber 60 is connected to the lower portion of the pressurized dissolved water holding chamber 50 through an opening 51. The water 200 in the pressurized dissolved water holding chamber 50 is discharged from the lower part of the pressurized dissolved water holding chamber 50 into the decompression chamber 60 through the opening 51. In the decompression chamber 60, the water 200 in which the large bubbles 201 are dissolved is discharged from the atmospheric pressure of about 0.3 MPa as the first pressure at once to the atmospheric pressure as the second pressure. When the pressure is reduced rapidly in this manner, cavitation occurs, and microbubbles having a diameter of 3 to 30 μm are discharged into the reduced pressure chamber 60 through the opening 51 in the water 200. The sectional area of the opening 51 shown in FIG. 2 is, for example, about 16 mm ² . The cylindrical inner diameter of the decompression chamber 60 is, for example, about 15 mm.

  Incidentally, a rotary blade 71 is disposed in the decompression chamber 60. When the motor 72 is driven, a single worm-shaped rotary blade 71 attached to the tip of the rotary shaft 70 rotates. When the rotational speed of the rotary blade 71 is increased, that is, when the rotational speed of the motor 72 is increased, the pressure in the decompression chamber 60 changes from atmospheric pressure to negative pressure, and the bubble ejection speed through the opening 51 is increased. Will be faster. The faster the bubble ejection speed, the smaller the bubble diameter. When the rotational speed (rotational speed) of the rotating blade body 71 exceeds a certain critical value, nanobubbles are generated. For example, the rotational speed of the rotary blade 71 is 500 r. p. m. Above this, nanobubbles are generated.

  Thus, in the nanobubble generator 1 of the present invention, the pressurized dissolved water held in the pressurized dissolved water holding chamber 50 is sent into the decompression chamber 60 through the opening 51 by the rotation of the rotary blade body 71. At this time, cavitation occurs due to rapid decompression, microbubbles are generated as fine bubbles, and are ejected into the decompression chamber 60.

  Further, by increasing the rotation speed of the rotary blade 71, the ejection speed in the decompression chamber 60 from the pressurized dissolved water holding chamber 50 can be increased. At this time, the pressure in the decompression chamber 60 further decreases, and the second pressure becomes a negative pressure. For this reason, nanobubbles having a diameter of 1 μm or less are generated as finer bubbles for more rapid decompression, and are ejected into the decompression chamber 60. Water containing nanobubbles ejected into the decompression chamber 60 is discharged to the outside through the discharge conduit 80. At this time, the inner diameter of the discharge pipe 80 is such a diameter that no pressure is applied to the water containing nanobubbles, and is, for example, about 10 mm.

  Therefore, in the nanobubble generator 1 of the present invention, the negative pressure in the decompression chamber 60 can be controlled by changing the rotational speed of the rotating blade body 71, that is, the rotational speed of the motor 72. The diameter can be controlled. In other words, the nanobubble generation conditions and the nanobubble diameter can be easily controlled simply by changing the rotational speed of the motor 72.

  That is, the nanobubble sending device 1 of the present invention does not apply physical stimulation such as vortex, crushing, centrifugal force, shearing force, etc., to the fine bubble mixture, but the rotational speed of the rotating blade body 71, that is, the rotational speed of the motor 72 By changing the pressure, the impact strength of cavitation and the bubble ejection speed at the time when the bubbles are discharged after being decompressed are changed, so that the conditions of the nanobubble generation mechanism itself are changed.

  Note that, in the nanobubble generator 1 of the present invention, the bubbles are somewhat miniaturized by physical stimulation such as the fragmentation of the bubbles by the rotating blade 71 and the collapse of the bubbles by impact.

  In the conventional bubble generating device, bubbles are generated by pressurizing mixed water of water and gas with a pump, and then depressurizing and discharging. In this case, the degree of microbubble generation is controlled by the pressure applied by the pump and the degree of opening of the decompression discharge valve.

  In the nanobubble generator 1 of the present invention, it is not necessary to change the pressure of the pressurizing pump 40 and the size of the gap of the opening 51. In other words, the pressure of the pressurizing pump 40 and the size of the gap of the opening 51 are changed. Without depending on this, the degree of decompression in the decompression chamber 60 can be controlled by changing the rotational speed of the rotary blade 71, that is, the rotational speed of the motor 72. As a result, the cavitation generation impact strength and the bubble ejection speed can be changed. As a result, the diameter of the generated nanobubbles can be freely controlled by electronically controlling the driving of the motor 72.

  In this case, if the number of worm-shaped strips of the rotating blade body 71 is 2 or more, the generated bubbles may be re-pressurized and crushed and disappear when passing around the rotating blade body 71. In order to prevent this, the number of worm-shaped strips of the rotary blade 71 is set to 1.

  Note that the interface of nanobubbles generated in water 200 containing electrolyte ions is negatively charged. Each nanobubble repels each other by electrostatic repulsion. In addition, it is considered that ions concentrated in the water 200 play a role like a shell enclosing the nanobubbles. Therefore, the nanobubbles collide with each other and do not easily disappear, and the nanobubbles do not disappear for a long time.

  It should be considered that the embodiments and examples disclosed above are illustrative and non-restrictive in every respect. The scope of the present invention is shown not by the above-described embodiments and examples but by the scope of claims, and includes all modifications and variations within the meaning and scope equivalent to the scope of claims.

1: Nanobubble generator, 40: Pressurized pump, 50: Pressurized dissolved water holding chamber, 51: Opening, 60: Depressurized chamber, 70: Rotating shaft, 71: Rotating blade, 72: Motor, 80: Discharge pipe Road, 101: intake pipe, 102, 103: water pipe.

Claims (1)

A channel through which water and gas flow;
Pressurized mixing that is disposed in the flow path and pressurizes water and gas supplied into the flow path to a first pressure and sends pressurized mixed water in which water and gas are mixed into the flow path A water supply,
A pressure-dissolved water holding chamber that is disposed in the flow path and holds the pressure-dissolved water in which the gas is dissolved in water by maintaining the pressure-mixed water at the first pressure;
A decompression chamber for depressurizing the pressurized dissolved water to a second pressure lower than the first pressure;
The pressurized dissolved water holding chamber and the decompression chamber are connected by an opening having a diameter that can pass the pressurized dissolved water,
A rotating shaft body disposed so as to penetrate the pressurized dissolved water holding chamber and the opening and reach the decompression chamber;
A worm-shaped rotary blade attached to the tip of the rotary shaft and disposed in the decompression chamber;
A motor for rotating the rotating shaft body;
A discharge line for discharging water and gas from the decompression chamber;
By rotating the rotating shaft body, the pressure-dissolved water is decompressed and ejected from the pressure-dissolved water holding chamber toward the pressure-reducing chamber through the opening, and the rotation speed of the motor is variable. A nanobubble generator.

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