JP2007000848A - Method for generating fine bubble - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method for generating fine bubbles, in which fine bubbles generated by pulverizing bubbles by a decompressing/pressurizing means can be furthermore made finer and by which the installation space of an apparatus can be saved by miniaturizing the apparatus and the energy consumption of the apparatus can also be saved. <P>SOLUTION: The method for generating fine bubbles comprises the steps of: pulverizing bubbles in a gas-mixed liquid flowing in a flow passage 1 by the decompressing/pressurizing means 2 to generate fine bubbles; and pulverizing the generated fine bubbles by a flow resistance 3 arranged on the downstream side of the decompressing/pressurizing means 2 to generate finer bubbles. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a fine bubble generating method for generating fine bubbles by pulverizing bubbles in a gas-liquid mixture with a decompression and pressurizing means.

  Conventionally, a method of generating fine bubbles by pulverizing bubbles in a gas-liquid mixed solution with a decompression / pressurization means is known (see, for example, Patent Document 1).

  In this conventional method for generating fine bubbles, a decompression / pressurization means is provided in the flow path of the gas-liquid mixture, and the bubbles in the gas-liquid mixture are generated by the decompression / pressurization of the decompression / pressurization means. It is pulverized by force to generate fine bubbles. The fine bubbles are those having a diameter of 1 mm or less and are difficult to rise in the liquid and have a high surface area per volume, and therefore have a high ability to adsorb dirt and float.

By the way, in the conventional method for generating fine bubbles, the diameter of the fine bubbles generated by pulverizing by the pressure reducing / pressurizing means is φ100 to 500 μm. Fine bubbles having a diameter of about several tens of μm (about 30 to 90 μm) could not be generated. In order to generate fine bubbles with a diameter of about several tens of μm, a method of precipitating the gas by depressurizing the dissolved liquid in the gas-liquid dissolution tank can be considered. In addition, it is not preferable because it causes an increase in power, and a method that can easily generate the fine bubbles is desired.
Japanese Patent No. 2722373

  The present invention has been invented in view of the above-described conventional problems, and an object of the present invention is to provide a method for generating fine bubbles that can easily generate fine bubbles. is there.

  In order to solve the above-described problem, the fine bubble generating method of the present invention generates fine bubbles by pulverizing bubbles in a gas-liquid mixture flowing in the flow path 1 with the decompression and pressurizing means 2 and generating the fine bubbles. The fine bubbles are pulverized by a flow resistance 3 provided on the downstream side of the decompression / pressurizing means 2 to generate smaller fine bubbles.

  With such a configuration, it is possible to easily generate fine bubbles having a diameter of about several tens of μm (30 to 90 μm).

  The invention according to claim 2 is characterized in that, in claim 1, the flow resistance 3 is constituted by a mesh or an orifice. With such a configuration, the flow resistance 3 can be configured with a simple configuration.

  The invention according to claim 3 is characterized in that, in claim 1 or 2, vortex is generated in the vortex chamber 7 provided on the downstream side of the flow resistance 3. By setting it as such a structure, it becomes possible to produce | generate the fine bubble below a fixed magnitude | size.

  According to the present invention, it is possible to easily generate fine bubbles having a diameter of about several tens of μm, and space saving and energy saving can be achieved by downsizing the apparatus.

  Hereinafter, an embodiment of the present invention will be described with reference to FIGS. The microbubble generator used in the present invention is provided with a pressure reducing / pressurizing means 2 in a flow path 1 through which a gas-liquid mixed liquid flows, and a flow resistance 3 is provided downstream of the pressure reducing / pressurizing means 2 in the flow path 1. In this embodiment, as shown in FIG. 1, the upstream side (suction port side) is connected to the flow path 1 in which the suction port at one end and the nozzle 4 at the other end are respectively opened and communicated with a water tank such as a bathtub. ) To the downstream side (nozzle 4 side), a gas intake unit 5 for sequentially taking gas into the liquid and mixing the gas into the liquid, and a pump (not shown) for pressurizing the liquid mixed with the gas And a pressure reducing / pressurizing means 2 for pulverizing bubbles in the gas-liquid mixture to generate fine bubbles, and a flow resistance 3, and a nozzle 4 for discharging fine bubbles at the downstream end of the flow path 1. Is provided.

  The gas intake unit 5 includes an intake valve having an ejector mechanism, and when the liquid flows through the flow path 1 by driving the pump, the gas is taken into the liquid through the intake valve by the ejector effect and mixed with the gas. The internal pressure of the flow path 1 reaching the pressure reducing / pressurizing means 2 is maintained high. The gas intake unit 5 is not particularly limited, such as one that pumps gas by an air pump. Examples of the gas include, but are not limited to, oxygen, ozone, and air.

  The liquid mixed with the gas (gas-liquid mixed liquid) passes through the pump (which causes pressurization (positive pressure) in the piping) and flows to the pressure reducing / pressurizing means 2 on the downstream side.

  The pressure reducing / pressurizing means 2 is configured by providing a venturi tube in the flow path 1 between the pump and the nozzle 4 as shown in FIG. In the decompression / pressurization means 2 comprising the venturi tube 11, when the bubbles pass through the throat portion 12, the flow rate increases and the pressure is reduced and expanded, and then the pressure is increased and contracted as the cross-sectional area increases. The bubbles are refined by the shearing force generated at this time, and become fine bubbles having a diameter of φ100 to 500 μm. Then, the gas-liquid mixture mixed with fine bubbles flows to the downstream flow resistance 3.

  The flow resistance 3 is composed of a mesh or an orifice, and a turbulent flow region is generated when the gas-liquid mixture mixed with the fine bubbles passes through the flow resistance 3, and the fine force is generated by the shear force and pressure fluctuation generated in the turbulent flow region. The bubbles are pulverized to form fine bubbles having a finer diameter of about several tens of μm (particularly about φ30 to 90 μm). Then, fine bubbles which are about several tens of μm due to the flow resistance 3 are discharged from the nozzle 4.

  By adopting the configuration as described above, fine bubbles of about several tens of μm are efficiently generated by the flow resistance 3, and the apparatus is compared with a conventional device in which a gas-liquid dissolution tank is provided in the middle of the flow path 1. This simplifies the design, reduces the size, and does not require a power source.

  Next, another embodiment will be described with reference to FIG. In the present embodiment, the reduced pressure narrow tube portion 6 is provided on the downstream side of the flow resistance 3 and the vortex chamber 7 is provided on the downstream side thereof.

  The depressurized narrow tube portion 6 is a flow path that flows in a direction (substantially orthogonal) that intersects the flow direction of the portion where the pressure reducing / pressurizing means 2 and the flow resistance 3 provided in the flow path 1 are substantially linear. In this embodiment, it is provided with the flow path 1 as the center and facing outward in the present embodiment. In addition, a vortex chamber 7 is provided on the downstream side of the decompression narrow tube portion 6. The vortex chamber 7 is substantially perpendicular to the direction of the decompression narrow tube portion 6 and faces again in the same direction as the flow direction of the portion where the decompression / pressurization means 2 and flow resistance 3 of the flow path 1 are provided. A cavity protruding upstream from the inlet from the portion 6 is provided. The cavity of the vortex chamber 7 is larger than the width of the vacuum tube portion 6.

  When the liquid flowing through the flow path 1 passes through the reduced-pressure narrow tube portion 6, the dissolved gas is deposited by the reduced pressure to generate fine bubbles, and the reduced bubbles mixed in the liquid are reduced in pressure. Bubbles expand when passing through the narrow tube portion 6, and are then pulverized and further reduced by being rapidly pressurized in the vortex chamber 7. Then, a vortex is generated in the vortex chamber 7, and bubbles of a certain size or more are gathered at the center of the vortex due to the angular velocity of the vortex and are not discharged from the nozzle 4, and the bubbles gathered at the center of the vortex are stirred and fixed. The air bubbles are reduced in size and are discharged from the nozzle 4 at the downstream end. The size of the fine bubbles to be discharged is determined by the angular velocity of the vortex in the vortex chamber 7, and the smaller the bubble velocity, the smaller the bubble can be discharged, and the vortex angular velocity is variable depending on the flow velocity flowing into the vortex chamber 7. By changing the flow velocity of the flow into the vortex chamber 7, fine bubbles having a desired size can be generated.

1 is an overall configuration diagram of an embodiment of the present invention. (A) (b) is sectional drawing of the example of the principal part same as the above. It is an external appearance perspective view same as the above. Other embodiment is shown, (a) is principal part sectional drawing, (b) is the A section enlarged view of (a).

Explanation of symbols

1 Flow path 2 Pressure reducing / pressurizing means 3 Flow resistance

Claims (3)

  The bubbles in the gas-liquid mixture flowing in the flow path are pulverized by the pressure reducing / pressurizing means to generate fine bubbles, and the generated fine bubbles are flown by the flow resistance provided downstream of the pressure reducing / pressurizing means. A method for generating fine bubbles, characterized by pulverizing to produce smaller fine bubbles.   2. The method of generating fine bubbles according to claim 1, wherein the flow resistance is constituted by a mesh or an orifice.   The method of generating fine bubbles according to claim 1 or 2, wherein a vortex is generated in a vortex chamber provided downstream of the flow resistance.

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