KR102596334B1 - Nano bubble generating apparatus and method for controlling the size of nano bubble by using surfactant in acoustic cavitation method - Google Patents

Abstract

One embodiment of the present invention provides a nanobubble generating device and method for controlling the size of nanobubbles using a surfactant in an acoustic cavitation method which enable the generation of quantitatively size-controlled nanobubbles when generating nanobubbles through acoustic cavitation method, by controlling the zeta potential of nanobubbles by adjusting the concentration of the surfactant having various ionic properties such as cationic, anionic, and non-ionic when generating nanobubbles through the acoustic cavitation method.

Description

Nano bubble generating apparatus and method for controlling the size of nano bubbles by using surfactant in acoustic cavitation method}

The present invention relates to a nanobubble generating device and method. More specifically, when generating nanobubbles through an acoustic cavitation method, cationic, anionic, and nonionic ( An acoustic cavitation method that allows the generation of nanobubbles with quantitatively controlled sizes by controlling the zeta potential of nanobubbles by controlling the concentration of surfactants with various ionic properties such as non-ionic. This relates to a nanobubble generating device and method that allows the size of nanobubbles to be controlled using a surfactant.

In general, nanobubbles can be used in various industrial environments such as agriculture, wastewater treatment, surface treatment, and contrast agent. The above-mentioned nanobubbles have a size that produces optimal efficiency depending on each industrial environment.

These nanobubbles can be created through several methods, including a method using a membrane, a method using a static mixer, and an acoustic cavitation method.

Among these, the acoustic cavitation method is widely used due to its simplicity in generating nanobubbles and its various uses.

The acoustic cavitation method generates ultrasonic waves using a piezoelectric ultrasonic vibration element, and nanobubbles are generated due to the generated ultrasonic waves.

In this acoustic cavitation method, it is difficult to change the size of nanobubbles without replacing the piezoelectric ultrasonic vibration element itself or constructing a multi-stage nanobubble generating device with different piezoelectric ultrasonic vibration elements that shear the nanobubbles to different sizes. difficult.

In other words, the acoustic cavitation method is a method for generating nanobubbles of a desired size without changing the piezoelectric ultrasonic vibration element or configuring a multi-stage nanobubble generating device with different piezoelectric ultrasonic vibration elements that shear the nanobubbles to different sizes. Not yet established.

Therefore, when applying the acoustic cavitation method to generate nanobubbles, the size of the nanobubbles can be quantitatively controlled without changing the piezoelectric ultrasonic vibration element or configuring a multi-stage nanobubble generating device with different piezoelectric ultrasonic vibration elements. A method to enable this is required.

Republic of Korea Patent No. 10-2165936 (published on October 7, 2019, announced on October 14, 2020)

The present invention, which aims to solve the problems of the prior art described above, creates nanobubbles whose size is controlled quantitatively by using changes in electrical properties (zeta potential) generated by the concentration of surfactants with various ionic properties. The problem to be solved is to provide a nanobubble generating device and a nanobubble generating method that can control the size of nanobubbles using a surfactant in the acoustic cavitation method that allows manufacturing.

The technical problem to be achieved by the present invention is not limited to the technical problem mentioned above, and other technical problems not mentioned can be clearly understood by those skilled in the art from the description below. There will be.

In order to achieve the above technical problem, an embodiment of the present invention includes a control unit that calculates the concentration of a surfactant supplied to the solvent to generate nanobubbles of a target size and generates and outputs an ultrasonic generation control signal; an ultrasonic applicator that generates and applies ultrasonic waves according to an ultrasonic generation control signal from the controller; and a nanobubble generating chamber unit that accommodates the solvent and the surfactant and then generates nanobubbles of a target size by ultrasonic waves applied from the ultrasonic applicator. do.

The surfactant may have any one of ionic characteristics: cationic, anionic, or non-ionic.

The nanobubble generating device further includes a nanobubble zeta potential measuring unit that measures the zeta potential of the nanobubble generated in the nanobubble generating chamber unit, and the control unit is configured to measure the zeta potential of the nanobubble generated in the nanobubble generating chamber unit. When the zeta potential differs from the target zeta potential within a set error range, it may be configured to perform surfactant concentration correction to calculate the amount of the surfactant or solvent to be additionally supplied in order to reduce the difference within the error range. there is.

The nanobubble generating device further includes a solvent/surfactant supply unit that receives the surfactant concentration control signal from the control unit and selectively supplies the surfactant, wherein the control unit controls the solvent/surfactant supply unit to control the surfactant concentration. It may be configured to additionally supply the solvent or surfactant in an amount calculated through correction of the surfactant concentration to the nanobubble generating chamber.

The nanobubble generating device further includes a nanobubble size measuring unit that measures the size of the nanobubbles generated in the nanobubble generating chamber unit, and the control unit determines the measured size of the nanobubbles within a set error range. If there is a difference compared to the size of the target nanobubble, it may be configured to perform surfactant concentration correction to calculate the amount of the surfactant or solvent to be additionally supplied in order to reduce the difference within an error range.

The nanobubble generating device further includes a solvent/surfactant supply unit that receives the surfactant concentration control signal from the control unit and selectively supplies the surfactant, wherein the control unit controls the solvent/surfactant supply unit to control the surfactant concentration. It may be configured to additionally supply the solvent or surfactant in an amount calculated through correction of the surfactant concentration to the nanobubble generating chamber.

The control unit may be configured to store one or more information among the type of surfactant, nanobubble size for each surfactant concentration, zeta potential size for each surfactant concentration, and nanobubble size information for each zeta potential.

Another embodiment of the present invention for achieving the above technical problem is a nanobubble generating method of a nanobubble generating device including a control unit, an ultrasonic applicator, and a nanobubble generating chamber unit, wherein the control unit generates nanobubbles of a target size. A surfactant type and concentration setting step of selecting the type of surfactant and calculating and setting the concentration; and an ultrasonic wave application step of applying ultrasonic waves through the ultrasonic wave applicator to the nanobubble generating chamber having a surfactant mixture or aqueous solution having the set surfactant type and concentration. provides.

The surfactant selected in the surfactant type and concentration setting step may have one of ionic characteristics: cationic, anionic, or non-ionic.

In the nanobubble generating method, the nanobubble generating device further includes a solvent/surfactant supply unit, and before the ultrasound application step, the solvent/surfactant supply unit supplies the surfactant selected in the surfactant type and concentration setting step. It may further include a surfactant aqueous solution manufacturing step of supplying the surfactant aqueous solution to the nanobubble generating chamber according to the set concentration information of the surfactant.

In the nanobubble generating method, the nanobubble generating device further includes a nanobubble zeta potential measuring unit or a nanobubble size measuring unit, and after the ultrasound application step, the nanobubble zeta potential measuring unit or the nanobubble size measuring unit. A nanobubble measuring step of measuring the size or zeta potential of nanobubbles generated in the nanobubble chamber using any one of the following; A nanobubble size determination step in which the control unit compares the measured size or zeta potential of the nanobubble with the size or zeta potential of a target nanobubble within a set error range; And as a result of the determination of the nanobubble size determination step, if the measured size or zeta potential of the nanobubble is different from the size or zeta potential of the target nanobubble within the set error range, the control unit reduces the difference to within the error range. It may further include a surfactant concentration correction step of calculating the amount of solvent or surfactant to be added.

The nanobubble generating device further includes a solvent/surfactant supply unit, and in the surfactant concentration correction step, the control unit controls the solvent/surfactant supply unit to supply the solvent or surfactant to be added into the nanobubble generating chamber. It may be a stage of providing additional wealth.

The nanobubble generating device and method for controlling the size of nanobubbles using a surfactant in the acoustic cavitation method of an embodiment of the present invention are used in agriculture, wastewater treatment, and surface treatment. , Contrast agent, etc., provide the effect of easily creating nanobubbles with a size that produces optimal efficiency according to various industrial environments by applying the acoustic cavitation method.

The effects of the present invention are not limited to the effects described above, and should be understood to include all effects that can be inferred from the configuration of the invention described in the detailed description or claims of the present invention.

Figure 1 is a schematic configuration diagram of a nanobubble generating device 1 according to an embodiment of the present invention.
Figure 2 is a flowchart showing the processing process of the nanobubble generation method of another embodiment of the present invention.
Figure 3 is a diagram showing nanobubbles 2 observed by Nanoparticle Tracking Analysis (NTA).
Figure 4 is a graph showing the diameter of nanobubbles measured according to the concentration of cetrimonium bromide (CTAB), a cationic surfactant.
Figure 5 is a graph showing the diameter of nanobubbles measured according to the concentration of sodium dodecyl sulfate (SDS), an anionic surfactant.
Figure 6 is a graph showing the diameter of nanobubbles measured according to the concentration of Tween 20, a non-ionic surfactant.

Hereinafter, the present invention will be described with reference to the attached drawings. However, the present invention may be implemented in various different forms and, therefore, is not limited to the embodiments described herein. In order to clearly explain the present invention in the drawings, parts that are not related to the description are omitted, and similar parts are given similar reference numerals throughout the specification.

Throughout the specification, when a part is said to be "connected (connected, contacted, combined)" with another part, this means not only "directly connected" but also "indirectly connected" with another member in between. "Includes cases where it is. In addition, when a part is said to “include” a certain component, this does not mean that other components are excluded, but that other components can be added, unless specifically stated to the contrary.

The terms used herein are only used to describe specific embodiments and are not intended to limit the invention. Singular expressions include plural expressions unless the context clearly dictates otherwise. In this specification, terms such as “comprise” or “have” are intended to designate the presence of features, numbers, steps, operations, components, parts, or combinations thereof described in the specification, but are not intended to indicate the presence of one or more other features. It should be understood that this does not exclude in advance the possibility of the existence or addition of elements, numbers, steps, operations, components, parts, or combinations thereof.

Hereinafter, embodiments of the present invention will be described in detail with reference to the attached drawings.

Figure 1 is a schematic configuration diagram of a nanobubble generating device 1 according to an embodiment of the present invention.

As shown in FIG. 1, the nanobubble generating device 1 according to an embodiment of the present invention calculates the concentration of the surfactant supplied to the solvent to generate nanobubbles of the target size, and generates an ultrasonic generation control signal. After receiving the control unit 10 to output the ultrasonic waves, the ultrasonic applicator 30 to generate and apply ultrasonic waves according to the ultrasonic generation control signal of the control unit 10, and the solvent and surfactant, the ultrasonic applicator 30 It may be configured to include a nanobubble generating chamber unit 40 that generates nanobubbles of a target size by applied ultrasonic waves.

The surfactant may have any one of ionic characteristics: cationic, anionic, or non-ionic.

The control unit 10 controls the operation of the nanobubble generator 1 and is configured to select the type of surfactant for generating nanobubbles of the target size, calculate the concentration, and set the type and concentration of the surfactant. It can be.

To this end, the control unit 10 may be configured to store information on the type of surfactant, nanobubble size or zeta potential size for each surfactant concentration, and nanobubble size information for each zeta potential.

The ultrasonic applicator 30 includes an ultrasonic signal generator 31 that generates and outputs an ultrasonic signal corresponding to the ultrasonic waves generated under the control of the control unit 10, and an ultrasonic signal generator 31 that generates and outputs an ultrasonic signal corresponding to the ultrasonic wave generated under the control of the control unit 10. A signal amplification unit 33 amplifies and outputs an ultrasonic signal, and the solvent/surfactant mixture solution contained inside the nanobubble chamber 40 generates ultrasonic waves using the ultrasonic signal amplified and output from the signal amplification unit 33. Alternatively, it may be configured to include an ultrasonic wave generator 35 that applies ultrasonic waves to an aqueous solution.

The ultrasonic generator 35 may be configured to receive an ultrasonic signal output from the signal amplifier 33, generate ultrasonic waves by vibrating them, and apply them to the solvent-surfactant mixture or aqueous solution. The ultrasonic generator 35 may be composed of a piezoelectric ultrasonic vibrator or the like.

In addition, the ultrasonic applicator 30 further includes a current/voltage detection unit 37 that detects the current or voltage of the amplified ultrasonic signal applied from the signal amplifier 33 to the ultrasonic generator 35. It can be configured. In this case, the ultrasonic signal generator 31 receives the current or voltage value detected by the current/voltage detection unit 37 so that the generated ultrasonic waves have a preset frequency and size within a preset error range. It may be configured to perform feedback control to adjust and output a signal.

The size and frequency of the ultrasonic waves applied by the ultrasonic wave applicator 30 may be fixed or varied to preset values for nanobubble generation.

The nanobubble generating device 1 may further include a nanobubble zeta potential measuring unit 50 that measures the zeta potential of the nanobubbles generated in the nanobubble generating chamber unit 40. .

In this case, the control unit 10 compares the measured zeta potential of the nanobubble with the target zeta potential within the set error range, and if there is a difference, the surfactant or solvent to be additionally supplied to reduce the difference within the error range. It may be configured to perform surfactant concentration correction to calculate the amount of.

The nanobubble generating device 1 may further include a nanobubble size measuring unit 60 that measures the size of nanobubbles generated in the nanobubble generating chamber unit 40. The nanobubble size measuring unit 60 may be configured as a Nanoparticle Tracking Analysis (NTA) system.

In this case, the control unit 10 compares the measured size of the nanobubble with the size of the target nanobubble within a set error range, and if there is a difference, the surfactant to be additionally supplied or It may be configured to perform a surfactant concentration correction to calculate the amount of solvent.

In addition, the nanobubble generating device 1 may further include a solvent/surfactant supply unit 20 that receives a surfactant concentration control signal from the control unit 10 and selectively supplies the surfactant.

In this case, the control unit 10 controls the solvent/surfactant supply unit 20 to supply an additional amount of the solvent or surfactant calculated through correction of the surfactant concentration to the nanobubble generating chamber unit 40. It can be configured to provide additional supply.

In the above-described nanobubble generating device 1, the control unit 10 may be composed of hardware implemented to perform the functions of the control unit 10. Additionally, the control unit 10 may be a personal computer, tablet, smartphone, etc. equipped with software that performs the functions of the control unit 10.

Figure 2 is a flowchart showing the processing process of the nanobubble generation method of another embodiment of the present invention.

As shown in FIG. 2, the nanobubble generating method is a nanobubble generating method of the nanobubble generating device 1 including a control unit 10, an ultrasonic wave applicator 30, and a nanobubble generating chamber unit 40, A surfactant type and concentration setting step (S10) in which the control unit 10 selects the type of surfactant for generating nanobubbles of the target size, calculates the concentration, and sets the surfactant type and concentration. It may be configured to include an ultrasonic wave application step (S30) of applying ultrasonic waves through the ultrasonic wave applicator 30 to the nanobubble generating chamber unit 40 containing the mixed solution or aqueous solution.

In addition, when the nanobubble generating device 1 further includes a solvent/surfactant supply unit 20, the nanobubble generating method includes the solvent/surfactant supply unit 20 before the ultrasound application step (S30). ) supplies the surfactant selected in the surfactant type and concentration setting step (S10) to the nanobubble generation chamber unit 40 according to the set concentration information of the surfactant to prepare an aqueous surfactant solution. It may further include step (S20).

In addition, when the nanobubble generating device 1 further includes a nanobubble zeta potential measuring unit 50 or a nanobubble size measuring unit 60, the nanobubble generating method includes the ultrasonic wave application step (S30) Afterwards, a nanobubble measurement step ( S40), a nanobubble size determination step (S50) in which the control unit 10 compares the measured size or zeta potential of the nanobubble with the size or zeta potential of a target nanobubble within a set error range, and the nanobubble size determination step As a result of the judgment in (S50), if the measured size or zeta potential of the nanobubble is different from the size or zeta potential of the target nanobubble within the set error range, the control unit 10 reduces the difference to within the error range. It may further include a surfactant concentration correction step (S60) for calculating the amount of solvent or surfactant to be added.

In addition, when the nanobubble generating device 1 further includes the solvent/surfactant supply unit 20, the surfactant concentration correction step (S60) is performed when the control unit 10 controls the solvent/surfactant supply unit 20. This may be a step of additionally supplying the solvent or surfactant to be added to the nanobubble generating chamber unit 40 by controlling (20).

The nanobubble generating device 1 and the nanobubble generating method of an embodiment of the present invention configured as described above select or set the type and concentration of the surfactant according to the size or zeta potential value of the target nanobubble. Thereafter, a mixture or aqueous solution of the selected surfactant having the selected concentration value is prepared using an amount of the surfactant corresponding to the selected concentration and a solvent such as water or distilled water. Thereafter, ultrasonic waves having a preset frequency or intensity are applied to the surfactant mixture or aqueous solution. When the ultrasonic waves are applied, nanobubbles are formed inside the solvent. And the surfactant particles are attached to the surface of the generated nanobubble. In this case, a different zeta potential is generated depending on the concentration of the surfactant, and the size of the nanobubble changes in response to the generated zeta potential. As a result, nanobubbles having a target diameter or size corresponding to the set zeta potential are generated. And the zeta potential can be controlled by varying the concentration of the surfactant. Accordingly, embodiments of the present invention can easily control the size of nanobubbles by adjusting the zeta potential of the nanobubbles by adjusting the concentration of the surfactant, so that nanobubbles of the desired size can be easily generated. do.

<Experimental example>

Figure 3 is a diagram showing nanobubbles 2 observed by Nanoparticle Tracking Analysis (NTA).

The thing shown in white in Figure 3 is the nanobubble (2). In the case of Figure 3, the concentration of nanobubbles was about 10 ⁹ /ml.

Figure 4 is a graph showing the diameter of nanobubbles measured according to the concentration of cetrimonium bromide (CTAB), a cationic surfactant.

Figure 4 shows that the diameter of nanobubbles generated at each surfactant concentration value was measured multiple times (e.g., more than 6 times), and the average diameter of the nanobubbles (Average Diameter, nm) was measured as the size of the nanobubbles.

As a result of the measurement in Figure 4, in the case of Cetrimonium bromide (CTAB), a cationic surfactant, the interface has a minimum diameter of 115.35nm when the nanobubble diameter is 0mM, and a maximum of 382.5nm at 1.84 x 10 ^-2mM . The measurements were varied depending on the concentration of the activator.

Figure 5 is a graph showing the diameter of nanobubbles measured according to the concentration of sodium dodecyl sulfate (SDS), an anionic surfactant.

As a result of the measurement in Figure 5, in the case of sodium dodecyl sulfate (SDS), an anionic surfactant, the diameter of the nanobubble is at least 115.35 nm at 0mM, and at the concentration of the surfactant from 16.4mM to a maximum of 168.15 nm. It was measured and varied accordingly.

Figure 6 is a graph showing the diameter of nanobubbles measured according to the concentration of Tween 20, a non-ionic surfactant.

As a result of the measurement in Figure 6, in the case of Tween 20, a non-ionic surfactant, the nanobubble diameter is at least 115.35 nm at 0mM, and at 12x10 ^-2mM up to 176.47nm, depending on the concentration of the surfactant. It was measured and varied.

The description of the present invention described above is for illustrative purposes, and those skilled in the art will understand that the present invention can be easily modified into other specific forms without changing the technical idea or essential features of the present invention. will be. Therefore, the embodiments described above should be understood in all respects as illustrative and not restrictive. For example, each component described as unitary may be implemented in a distributed manner, and similarly, components described as distributed may also be implemented in a combined form.

The scope of the present invention is indicated by the patent claims described below, and all changes or modified forms derived from the meaning and scope of the claims and their equivalent concepts should be construed as being included in the scope of the present invention.

1: Nanobubble generating device
2: Nanobubble
10: control unit
20: Solvent/surfactant supply unit
30: Ultrasonic authorization unit
35: Ultrasonic generator
40: Nanobubble generation chamber part
50: Nanobubble zeta potential measurement unit
60: Nanobubble size measurement unit

Claims (12)

A control unit that calculates the concentration of the surfactant supplied to the solvent to generate nanobubbles of the target size and generates and outputs an ultrasonic generation control signal;
a solvent/surfactant supply unit that selectively supplies surfactant by receiving a surfactant concentration control signal from the control unit;
an ultrasonic applicator that generates and applies ultrasonic waves according to an ultrasonic generation control signal from the controller; and
Characterized in that it comprises a nanobubble generating chamber unit that receives the solvent and the surfactant and then generates nanobubbles of a target size by ultrasonic waves applied from the ultrasonic applicator,
The control unit is configured to control the solvent/surfactant supply unit to additionally supply the solvent or surfactant in the amount to be additionally supplied calculated through correction of the surfactant concentration to the nanobubble generating chamber unit. Generating device. The method of claim 1, wherein the surfactant is,
A nanobubble generating device characterized by having one of cationic, anionic, or non-ionic ionic characteristics. According to paragraph 1,
It further includes a nanobubble zeta potential measurement unit that measures the zeta potential of the nanobubbles generated in the nanobubble generation chamber unit,
The control unit,
The measured zeta potential of the nanobubble is compared with the target zeta potential within the set error range, and if there is a difference, surfactant concentration correction to calculate the amount of the surfactant or solvent to be additionally supplied in order to reduce the difference within the error range. A nanobubble generating device, characterized in that it is configured to perform. delete According to paragraph 1,
It further includes a nanobubble size measuring unit that measures the size of the nanobubbles generated in the nanobubble generating chamber unit,
The control unit,
The measured size of the nanobubble is compared with the size of the target nanobubble within the set error range, and if there is a difference, the surfactant concentration calculates the amount of the surfactant or solvent to be additionally supplied in order to reduce the difference within the error range. A nanobubble generating device, characterized in that it is configured to perform correction. According to clause 5,
It further includes a solvent/surfactant supply unit that receives the surfactant concentration control signal from the control unit and selectively supplies the surfactant,
The control unit is configured to control the solvent/surfactant supply unit to additionally supply the solvent or surfactant in the amount to be additionally supplied calculated through correction of the surfactant concentration to the nanobubble generating chamber unit. Generating device. The method of claim 1, wherein the control unit:
A nanobubble generating device, characterized in that it is configured to store one or more information among the type of surfactant, nanobubble size for each surfactant concentration, zeta potential size for each surfactant concentration, and nanobubble size information for each zeta potential. In the nanobubble generating method of the nanobubble generating device including a control unit, solvent/surfactant supply unit, ultrasonic applicator, and nanobubble generation chamber unit,
A surfactant type and concentration setting step in which the control unit selects a type of surfactant for generating nanobubbles of a target size and calculates and sets the concentration;
A surfactant aqueous solution preparation step in which the solvent/surfactant supply unit supplies the surfactant selected in the surfactant type and concentration setting step to the nanobubble generating chamber unit according to the set concentration information of the surfactant to prepare an aqueous surfactant solution; and
A nanobubble generating method comprising: applying ultrasonic waves through the ultrasonic applicator to the nanobubble generating chamber having a surfactant mixture or aqueous solution having the set surfactant type and concentration. According to clause 8,
The surfactant selected in the surfactant type and concentration setting step generates nanobubbles, characterized in that the surfactant has one of ionic characteristics: cationic, anionic, or non-ionic. method. delete According to clause 8,
The nanobubble generating device further includes a nanobubble zeta potential measurement unit or a nanobubble size measurement unit,
After the ultrasonic wave application step, a nanobubble measuring step of measuring the size or zeta potential of nanobubbles generated in the nanobubble generating chamber unit using either the nanobubble zeta potential measuring unit or the nanobubble size measuring unit;
A nanobubble size determination step in which the control unit compares the measured size or zeta potential of the nanobubble with the size or zeta potential of a target nanobubble within a set error range; and
As a result of the determination of the nanobubble size determination step, if the measured size or zeta potential of the nanobubble is different from the size or zeta potential of the target nanobubble within the set error range, the control unit reduces the difference to within the error range. A method for generating nanobubbles, further comprising a surfactant concentration correction step of calculating the amount of solvent or surfactant to be added. According to clause 11,
The nanobubble generating device further includes a solvent/surfactant supply unit,
The surfactant concentration correction step is,
A nanobubble generating method, wherein the control unit controls the solvent/surfactant supply unit to additionally supply the solvent or surfactant to be added to the nanobubble generating chamber unit.