Micro air bubble generation device and method, water treatment device using the same

Abstract

The invention provides an apparatus and a method for producing microbubbles. Fluid in which gas is dissolved under pressure with a pump 1 flows into a porous plate unit 4 and when passing through the porous plate, the fluid is decompressed and dissolved gas is deposited to form microbubbles. A controller 3 changes rotational frequency of the pump 1 via an inverter 2 to control an ejection flow rate of microbubble-containing water 11. At the same time, the controller 3 changes the number of pores in a narrow flow passage via a driving gear 7 to keep pressurizing pressure above a minimum value of pressure required for producing microbubbles and below a predetermined maximum value.

Description

technical field [0001] The present invention relates to a micro-bubble generating device and method for stabilizing the diameter and amount of micro-bubbles, and a water treatment device using micro-bubbles that can be used for purification, sterilization, and disinfection of tap water, sewer water, river water, lake water, and industrial drainage. . Background technique [0002] Non-Patent Document 1 describes the use and effects of microbubbles in purification, sterilization, and disinfection. In addition, Non-Patent Document 2 describes the bactericidal effect of ozone water. In the description of Non-Patent Document 1, microbubbles are bubbles with a diameter of 50 micrometers or less called microbubbles. Generally, for bubbles in this diameter range, the gas in the bubbles dissolves into the surrounding liquid phase, and the diameter decreases. Therefore, under the action of surface tension, the internal components are in a state of high pressure and high temperature,...

AI Technical Summary

Problems solved by technology

[0013] In the prior art described in Non-Patent Document 1, the characteristics of microbubbles are described, but the generation method of microbubbles and the specific water treatment method are not disclosed.

In addition, the prior art described in Non-Patent Document 2 is a method of generating air bubbles by shearing the impeller of the pump. In this air bubble generation method, there is a problem that the air bubbles are not fine enough.

[0014] In the prior art described in Patent Document 1, the mixed water is pressurized by a high-pressure pump on the upstream side of the orifice, and is decompressed when passing through the orifice, so that tiny air bubbles can be generated. However, due to the flow path area of ​​the orifice It is fixed, so when it is necessary to change the necessary flow rate of the mixed water with ozone micro-bubbles, there is a problem that this requirement cannot be met

In addition, when the pressurized pressure changes, the diameter and the amount of generation of micro-bubbles also change, so the ozone dissolution efficiency changes and the water treatment capacity becomes unstable.

When changing the pressurized pressure and flow rate in this way, it is possible to provide a bypass flow path with a flow rate adjustment valve in the high-pressure pump and let a part of the mixed water pass through the bypass flow path. The mixed water flowing through the flow path is not sent to the orifice, but is wasted, increasing the loss of power supplied to the high-pressure pump

[0015] In the prior art described in Patent Document 2, the pressurization pressure of the orifice is controlled by adjusting the rotational speed of the pump with an inverter. However, since the flow path area of ​​the orifice is fixed, the Therefore, when the required flow rate of water mixed with ozone microbubbles changes, the pressurized pressure will change, and microbubbles cannot be stably generated.

[0016] In the prior art described in Patent Document 3, the throttling of the flow path of the orifice can be adjusted, so that the pressurized pressure can be controlled. According to this method, although the flow rate of the water mixed with ozone microbubbles can also be controlled, when throttling When the flow path restriction of the hole changes, the flow velocity when passing through the orifice changes, and the decompression amount of the orifice portion for generating microbubbles also changes.

Therefore, when the balance of pressurization and decompression changes, the diameter and generation amount of microbubbles also change, so the ozone dissolution efficiency changes, and the water treatment capacity becomes unstable.

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