JP2003251336A - Floatation separation method and apparatus used for the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a floatation separation method in which time required for floating is short and separation efficiency is good even when ultrafine air bubbles are used, and also to provide a floatation separation apparatus used for the same. <P>SOLUTION: This apparatus is provided with a floatation separation tank 1 for storing a treatment liquid, a pump 5 for forming the ultrafine air bubbles which forms ultrafine air bubbles X that adsorb the object materials for separation in the treatment liquid within the floatation separation tank 1, an outlet port 10 for discharging the ultrafine air bubbles which discharges the ultrafine air bubbles X that the pump 5 forms into the treatment liquid, an ultrasonic transducer 21 for generating ultrasonic wave which is applied to the treatment liquid and air bubbles, and an ultrasonic source 22 for impressing a voltage to the ultrasonic transducer 21. The ultrafine air bubbles X are floated due to the buoyancy generated by the sound pressure through the ultrasonic wave and the treatment liquid, and the object materials for separation adsorbed to the ultrafine air bubbles X are separated from the treatment liquid. <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a flotation method and a flotation device, and supplies air bubbles to an aqueous solution to be treated stored in a treatment tank to adsorb the substance to be separated in the aqueous solution to the aqueous solution. TECHNICAL FIELD The present invention relates to a levitation separation method and a levitation separation device in which air bubbles are floated by buoyancy received from a material and a substance to be separated adsorbed on the air bubbles is separated from an aqueous solution.

[0002]

2. Description of the Related Art FIG. 8 is a diagram for explaining the outline of a conventional flotation device. 600 is a floating separation device. The levitation separation apparatus 600 is a levitation separation tank 1 in which an aqueous solution to be treated (hereinafter referred to as a “treatment liquid”) is subjected to levitation separation treatment, and a substance to be separated in the treatment liquid is adsorbed by fine bubbles to be levitation-separated. A processing liquid charging line 2 for charging the processing liquid into the floating separation tank 1, a discharge line 3 for discharging the processing liquid which has been subjected to the floating separation processing from the floating separation tank 1, and a processing discharged from the discharge line 3. It has a circulation line 4 for circulating the liquid to the flotation separation tank 1 again, and a fine bubble formation pump 5 for forming fine bubbles in the treatment liquid circulating from the circulation line 4 to the flotation separation tank 1. .

The flotation / separation device 600 further comprises a sludge extraction line 6 for extracting sludge settling at the bottom of the flotation / separation tank 1, a sludge extraction valve 7 for opening / closing the sludge extraction line 6, and the flotation / separation tank 1 A floating sludge discharge port 8 for discharging the floating sludge Y adsorbed by the fine bubbles X on the surface of the treatment liquid and floating, and a floating sludge tank 9 for storing the floating sludge Y discharged from the floating sludge discharge port 8. In order to form fine bubbles in the fine bubble formation pump 5, and a fine bubble discharge port 10 for discharging the treatment liquid containing the fine bubbles formed by the fine bubble formation pump 5 into the treatment liquid in the floating separation tank 1. Air intake line 11 for inhaling air
And have.

In this conventional flotation / separation device 600, the microbubbles X formed by the microbubble formation pump 5 are discharged into the treatment liquid in the flotation / separation tank 1 from the microbubble discharge port 10 to float in the treatment liquid. The substances and dissolved components are adsorbed to the fine bubbles X, and the buoyancy of the fine bubbles X causes the levitation separation tank 1 to float, and the levitation sludge Y is discharged from the levitation sludge discharge port 8 into the levitation sludge tank 9. There is.

FIG. 9 is a diagram for explaining the concept of a conventional floating separation method. A schematic diagram is shown in (a), and a vector diagram of force is shown in (b). As shown in (a), the fine air bubbles X are formed of the separation target substances Y ₁ , Y ₂ , Y ₃ , Y ₄ , Y ₄ ,
Floating force F while attracting Y ₅ , Y ₆ ...
Ascend by ₁ (b).

[0006]

The above-mentioned conventional flotation / separation device is adapted to levitate fine air bubbles adsorbing suspended substances and dissolved components by buoyancy and discharge them as floating sludge. Further, in general, the smaller the fine bubbles, the easier the fine bubbles adsorb small floating substances and dissolved components. Therefore, there is a demand in the levitation separation device to make the diameter of the fine bubbles as small as possible.

However, in the conventional flotation device,
Since levitation separation is performed only by buoyancy, there is a problem that the smaller the diameter of the fine bubbles, the smaller the buoyancy, the longer the levitation time, and the lower the levitation separation efficiency.

Therefore, the present invention has been made in view of the above, and an object thereof is to provide a levitation separation method and a levitation separation device in which the levitation time is short and the levitation separation efficiency is good even if ultrafine bubbles are used. And

[0009]

In order to achieve the above object, the floating separation method according to the present invention supplies air bubbles to an aqueous solution to be treated, which flows into a treatment tank, so as to remove a substance to be separated in the aqueous solution. Characterized by adsorbing to bubbles and irradiating ultrasonic waves toward the aqueous solution and the bubbles, and promoting the levitation of the bubbles by the acoustic pressure of the ultrasonic waves to enhance the efficiency of separating the substance to be separated adsorbed on the bubbles from the aqueous solution. And

According to this structure, the bubbles receive not only the buoyancy force received from the aqueous solution but also a large acoustic pressure due to the ultrasonic waves. Therefore, the bubbles are pushed up faster than the buoyancy force alone and above the buoyancy force. Become.
Therefore, the substance to be separated in the aqueous solution to be treated is adsorbed by the bubbles and floats, and is separated from the aqueous solution. In the narrow sense, the ultrasonic wave refers to a sound wave having a frequency of 20 [kHz] or higher, but here, even if the frequency is 20 [kHz] or lower, the bubbles can be pushed up by sound pressure. Good.

By the way, an interaction energy given by the equation 1 works between particles in an aqueous solution (for example, refer to intermolecular force and surface tension, 2nd edition, JN Israel Achivili, Asakura Shoten 75P). Here, k is Boltzmann's constant, T is absolute temperature, r is center distance between particles, ε _r is relative permittivity of aqueous solution (≈78), and ε _r1 is relative permittivity of bubble (≈
1), ε _r2 is the relative permittivity of the substance to be separated, a ₁ is the bubble radius, and a ₂ is the radius of the dissolved substance.

[0012]

[Equation 1] Therefore, when one of the particles is a bubble, the interaction energy given by the equation 1 works between the separation target substance in the aqueous solution and the bubble. In particular, an attractive force acts between the air bubbles and the separation target substance having a relative dielectric constant smaller than that of the aqueous solution (? 78). The relative permittivity of an aqueous solution is 78, the relative permittivity of bubbles is 1, and the relative permittivity of an organic substance as a separation target substance is 1
When it is 0 or less, the separation target substance and the bubbles are attracted to each other. Therefore, when the bubbles are supplied into the processing tank, the substance to be separated is adsorbed by the bubbles and floated and separated by the buoyancy. In addition, as described above, rather than floating and separating the bubbles adsorbing the separation target substance only by the buoyancy,
By pushing up the bubbles by the sound pressure of the ultrasonic waves as in the present invention, it becomes possible to shorten the time required for the floating separation.

FIG. 7 is a diagram for explaining the concept of the floating separation method of the present invention. A schematic diagram is shown in (a), and a vector diagram of force is shown in (b). (A), the fine bubble X, while adsorption attract separation target substance _{Y 1, Y 2, Y 3} , Y 4, Y 5, Y 6 ···, floats by buoyancy F ₁ Go. When the ultrasonic vibrator Z irradiates ultrasonic waves thereto, a sound pressure F ₂ acts on the fine bubbles X. Then, the fine bubbles X float by the resultant force of the buoyancy F ₁ and the sound pressure F ₂ (b). The sound pressure F ₂ is increased by applying strong ultrasonic waves to the buoyancy F ₁
Therefore, according to the floating separation method of the present invention, the fine bubbles X are forcibly lifted as compared with the conventional case using only the buoyancy F ₁ .

On the other hand, in the floating separation treatment, it is preferable to supply ultrafine bubbles to the treatment tank. Since ultrafine bubbles with a small bubble radius a ₁ are close to the separation target substance and the value of a ₁ / r ⁶ in Formula ₁ becomes large, the interaction energy becomes large and even small separation target substances are adsorbed. Because you can. However, when the bubble radius becomes small like the ultrafine bubbles, the rising speed becomes slow, and the bubbles that have adsorbed the substance to be separated do not rise easily, so that the separation efficiency becomes poor. For example, the bubble radius is 20 [μm] even though the ascent rate is about 100 [mm / min].
Since the ascending speed is about 12 to 24 mm / min, the separation efficiency is deteriorated. Therefore, the floating separation method of the present invention is particularly effective when ultrafine bubbles having a slow rising speed are used.

The levitation separation method according to the next invention is characterized in that the irradiation of ultrasonic waves is performed during the supply of bubbles. According to this configuration, the bubbles are pushed up by the ultrasonic waves every time the bubbles are supplied, so that the separation work can be performed more quickly. At this time, the bubbles adsorb the substance to be separated while being pushed up by the ultrasonic waves.

The levitation separation method according to the next invention is characterized by irradiating ultrasonic waves after stopping the supply of bubbles. According to this configuration, ultrasonic waves are applied to suspend the supply of the bubbles and then the bubbles are floated, so that the bubbles can surely adsorb and separate the substances to be separated.

The levitation separation method according to the next invention is characterized by intermittently irradiating ultrasonic waves at predetermined intervals. According to this configuration, the bubbles adsorb the substance to be separated when the ultrasonic wave is not applied, and the bubbles that surely adsorb the substance to be separated are floated when the ultrasonic wave is applied. The separation process can be performed efficiently. In addition,
The frequency of the ultrasonic waves to be applied may be a frequency at which the bubbles adsorbing the substance to be separated and the aqueous solution both vibrate. In this way, the bubbles adsorbing the substance to be separated are easily dispersed in the aqueous solution, so that the bubbles can be efficiently floated,
The substance to be separated can be floated and separated from the aqueous solution.

Here, the frequency at which the bubbles adsorbing the substance to be separated and the aqueous solution both vibrate is Bramdt-H.
According to Iedemann's theory, when the ratio of the amplitude of the bubbles to the aqueous solution (the cosine value of the phase difference) is larger than 0.8, the bubbles in the aqueous solution are dispersed at a frequency such that they easily float. is there.

Generally, in an ultrasonic sound field, particles are
It is known to be moving according to the amdt-Hiedemann theory (hereinafter referred to as "BH theory") (Ultrasonic Technical Handbook (new edition) Supervisor: Junichi Yoshiyoshi, etc. Publisher: Nikkan Kogyo Shimbun Company August 10, 1987 New revision 6
See printing). In this BH theory, the state of particle motion in the ultrasonic sound field is determined from the phase shift difference (φ) between the particle and the medium. In addition, the phase shift difference (φ) is the particle amplitude (x
and _p), the amplitude ratio of the amplitude (x _l) of the medium (liquid) (x _p /
For equal to x _l), it can be calculated by the amplitude ratio (x _p / x _l). This amplitude ratio (x _p / x _l ) is the specific gravity (ρ) of the particle, the frequency (f), and the particle diameter (diameter) (d)
And the viscosity coefficient (viscosity of the liquid) (μ) of the medium can be calculated by the following equation.

[0020]

[Equation 2] In the case of cosφ≈0.8 to 0.2, there are many opportunities for particles to collide with each other and agglomerate. When cosφ> 0.8, the particles are completely vibrated with the liquid and thus dispersed. cosφ
In the case of <0.2, the stirring action due to the vibration of the particles is insufficient, and there is no opportunity for collision to cause aggregation.

By the way, the BH theory expresses the movement of particles with respect to a medium, but it can be inferred that bubbles in water also move like particles. Applying to Equation 1, it becomes the following equation. The viscosity coefficient of the aqueous solution (μ)
Is 1 × 10 ⁻³ [Pa · sec], and the specific gravity (ρ) of air (air bubbles) is 1.2 × 10 ⁻³ [g / cm ³ ] = 1.2 [k
g / m ³ ].

[0022]

[Equation 3] FIG. 6 is a graph showing the relationship between frequency and particle diameter, which represents the result of Equation 3. In the figure, the straight line α is cosφ =
In the case of 0.2, the straight line β is cosφ = 0.8 for particles, the straight line γ is cosφ = 0.2 for bubbles, and the straight line δ is cosφ = 0.8 for bubbles. Is shown. This graph shows that it is desirable to use a frequency in the vicinity of cos φ> 0.8 in order to efficiently increase the bubble size without increasing the bubble size. In case of particles, ρ = 3 ×
It is also shown when the calculation is performed at 10 ³ [kg / m ³ ]. Note that, in reality, since bubbles adhere to particles and have a large specific gravity, it is presumed that the optimum value is slightly on the particle side of the bubbles.

Therefore, for example, assuming a bubble diameter of 20 [μm], it is considered desirable to use a frequency near 1 [MHz]. In an actual experiment, 200 [kh
It is known that it is effective even from z]. The frequency of ultrasonic waves is 50 [μm] to 20 for ultrafine bubbles.
When the diameter is about 0 [μm], the ultrasonic frequency to be used is preferably 20 [kHz] to 1 [MHz], and when the ultrafine bubbles have a diameter of about 3 [μm] to 100 [μm]. Has
Ultrasonic frequency used is 100 [kHz] to 5 [MH]
z] is desirable.

The floating separation method according to the next invention is characterized in that the supplied bubbles are a plurality of bubbles including ultrafine bubbles having a diameter of several microns to several tens of microns.

As in this structure, even if the bubbles are ultrafine bubbles having a diameter of several microns to several tens of microns, they can be quickly levitated by the sound pressure of ultrasonic waves, so that the levitating separation work can be performed quickly. become able to. For example, even if it takes several hours when the force acting on the ultrafine bubbles is only buoyancy, it becomes possible to perform the separation work in about several minutes by applying ultrasonic sound pressure to the ultrafine bubbles. .

In the flotation separation apparatus according to the next invention, a treatment tank for storing an aqueous solution to be treated, a bubble generating means for generating bubbles for adsorbing a substance to be separated in the aqueous solution in the treatment tank, and the aqueous solution and the bubbles. It has an ultrasonic vibrator for generating ultrasonic waves to be radiated toward it, and an ultrasonic wave generating means for controlling the generation of the ultrasonic waves, and promotes the floating of the bubbles by the sound pressure of the ultrasonic waves to adsorb the bubbles. It is characterized in that the efficiency of separating the substance to be separated from the aqueous solution is increased.

According to this structure, the bubbles receive not only the buoyancy force received from the aqueous solution but also a large acoustic pressure due to the ultrasonic waves. Therefore, the bubbles are pushed up faster than the buoyancy force alone and above the buoyancy force. Become.
Therefore, after the substance to be separated in the aqueous solution to be treated is adsorbed by the bubbles, the acoustic pressure promotes the levitation to cause the levitation, and the efficiency of separation from the aqueous solution is improved.

The levitation separation device according to the next invention is characterized in that the ultrasonic wave generating means irradiates ultrasonic waves during the supply of bubbles. According to this configuration, the bubbles are pushed up by the ultrasonic waves every time the bubbles are supplied, so that the separation work can be performed more quickly.

The levitation separating apparatus according to the next invention is characterized in that the ultrasonic wave generating means irradiates ultrasonic waves after the supply of bubbles is stopped. According to this configuration, ultrasonic waves are applied to suspend the supply of the bubbles and then the bubbles are floated, so that the bubbles can surely adsorb and separate the substances to be separated.

The levitation separation device according to the next invention is characterized in that the ultrasonic wave generating means intermittently irradiates ultrasonic waves at predetermined intervals. According to this configuration, the bubbles adsorb the substance to be separated when the ultrasonic wave is not applied, and the bubbles that surely adsorb the substance to be separated are floated when the ultrasonic wave is applied. The separation process can be performed efficiently.

The levitation separating apparatus according to the next invention is characterized in that the ultrasonic transducer is provided in the lower portion of the processing tank. According to this configuration, the bubbles in the lower part of the processing tank are also floated to the upper part, so that the separation target substance in the aqueous solution in the lower part of the processing tank can be efficiently floated and separated.

The levitation separating apparatus according to the next invention is characterized in that the ultrasonic transducer is provided in the middle stage of the processing tank. According to this configuration, the bubbles near the middle stage of the processing tank can be efficiently floated. In particular, it is preferable to provide a plurality of ultrasonic transducers in the middle of the processing tank and the lower portion of the processing tank. In order to efficiently float the air bubbles near the middle stage of the processing tank,
Bubbles in the lower part of the processing tank can also be efficiently floated.

In the flotation separation device according to the next invention, the bubble generating means includes a bubble forming pump for sucking air into the aqueous solution to generate bubbles, and an ejection port for ejecting the aqueous solution containing the bubbles into the processing tank. , Are included. According to this structure, the bubbles formed by the bubble forming pump can be supplied from the ejection port into the processing tank.

In the flotation separation apparatus according to the next invention, the bubble generating means sends out an aqueous solution into the treatment tank, a delivery port for ejecting the aqueous solution containing bubbles into the treatment tank, the delivery pump and the above-mentioned delivery pump. A buffer tank which is disposed between the jet port and dissolves bubbles in the aqueous solution. According to this configuration, the pressurized air dissolved in the aqueous solution in the buffer tank, when the aqueous solution is supplied to the levitation separation tank at normal pressure, causes bubbles (particularly, ultrafine bubbles) formed by supersaturated air to be generated. It can be supplied into the processing tank. In particular, by controlling the pressure in the buffer tank, the diameter of bubbles formed can be adjusted, so that bubbles can be generated stably.

In the flotation separation device according to the next invention, in the buffer tank, pressurized air is dissolved in the aqueous solution and then depressurized to the atmospheric pressure, so that the supersaturated air component in the aqueous solution is generated as bubbles during depressurization. To do. According to this configuration, the aqueous solution is pressurized to mix and dissolve a little excess air than the saturated air amount, and the pressurized water in which the air is dissolved is mixed with the aqueous solution in the treatment tank through the pressure reducing valve, so that the pressure is reduced to supersaturation. The resulting air is deposited as bubbles, and the bubbles can be floated and separated by adhering the separation target substance of the aqueous solution in the treatment tank.

In the levitation separating device according to the next invention, the buffer tank has two electrode plates and a power source for applying a voltage between the electrode plates, and the voltage is applied between the electrode plates. It is characterized in that bubbles are generated by electrolysis. According to this configuration, bubbles generated by electrolysis in the buffer tank can be supplied to the processing tank.

In the levitation separating device according to the next invention, the buffer tank has two electrode plates and a power source for applying a voltage between the electrode plates, and the voltage is applied between the electrode plates. It is characterized in that bubbles are generated by electrolysis, and an aqueous solution in which pressurized air is dissolved flows out to reduce the pressure to atmospheric pressure to generate supersaturated air as fine bubbles.

According to this structure, since the aqueous solution is pressurized, it is possible to generate the necessary bubbles even with the electrode plate having a small surface area, and it is possible to easily generate the ultrafine bubbles when the pressure is reduced.

In the flotation separation device according to the next invention, the bubble generating means further has a discharge line for discharging the aqueous solution from the inside of the processing tank, and the aqueous solution discharged from the discharge line is sucked with air to generate bubbles. Is generated. According to this configuration, the bubbles are directly supplied to the aqueous solution in the treatment tank to be refluxed in the treatment tank, so that it is not necessary to newly supply the water containing the bubbles into the treatment tank, and the cost is reduced.

A flotation device according to the next invention is characterized in that the jet port is provided in the lower portion of the processing tank. According to this configuration, since the bubbles are supplied from the lower portion of the treatment tank, the separation target substance can be adsorbed by the bubbles over the entire aqueous solution in the treatment tank.

In the flotation separation device according to the next invention, the bubble generating means has two electrode plates installed in the processing tank, and a power source for applying a voltage between the electrode plates. It is characterized in that bubbles are generated by electrolysis by applying a voltage between them. According to this configuration, bubbles can be generated by electrolysis in the processing tank, and therefore it is not necessary to supply the bubbles from outside the processing tank.

A levitation separator according to the next invention is characterized in that the electrode plate is provided in the lower portion of the processing tank. According to this configuration, since the bubbles are supplied from the lower portion of the treatment tank, the separation target substance can be adsorbed by the bubbles over the entire aqueous solution in the treatment tank.

In the flotation separation apparatus according to the next invention, the bubble generating means is characterized in that the aqueous solution is depressurized and then depressurized in the processing tank to generate air components in the aqueous solution as bubbles during depressurization. According to this configuration, the aqueous solution is depressurized and then depressurized in the processing tank, and the air component in the aqueous solution can be generated as bubbles at the time of depressurization, so that it is not necessary to supply the bubbles from outside the processing tank.

The flotation device according to the next invention is characterized in that the bubble generating means supplies a plurality of bubbles including ultrafine bubbles having a diameter of several microns to several tens of microns.

Even if the bubbles are ultrafine bubbles having a diameter of several microns to several tens of microns as in this structure, they can be quickly floated by the sound pressure of ultrasonic waves, so that the floating separation work can be performed quickly. become able to. For example, even if it takes several hours when the force acting on the ultrafine bubbles is only buoyancy, it is possible to perform separation work in a few minutes by applying ultrasonic sound pressure to the ultrafine bubbles. Become. Here, the ultrafine bubbles having a diameter of about several microns to several tens of microns are bubbles having a floating speed of 1 [mm / s] or less when only buoyancy is applied.

The substance to be separated that has been adsorbed by the bubbles and floated as described above is discharged from the floating sludge discharge port as floating sludge. At this time, it is preferable to scrape.

[0047]

BEST MODE FOR CARRYING OUT THE INVENTION The present invention will now be described in detail with reference to the drawings. The present invention is not limited to this embodiment.

(Embodiment 1) FIG. 1 is a diagram for explaining the outline of a flotation device according to Embodiment 1 of the present invention. 10
Reference numeral 0 is a levitation separation device that floats bubbles by sound pressure due to ultrasonic waves and buoyancy received from the aqueous solution and separates suspended solids and dissolved components adsorbed by the bubbles from the aqueous solution.

The levitation separation apparatus 100 is a levitation separation tank in which a supplied aqueous solution (hereinafter referred to as "treatment liquid") is subjected to levitation separation treatment so that the substance to be separated in the treatment liquid is adsorbed by fine bubbles and levitation-separated. 1, a treatment liquid introduction line 2 for introducing the treatment liquid into the floating separation tank 1, a discharge line 3 for discharging the treatment liquid from the floating separation tank 1, and a treatment liquid discharged from the discharge line 3 again. It has a circulation line 4 for circulating it to the floating separation tank 1, and a fine bubble formation pump 5 for forming fine bubbles in the treatment liquid that is circulated from the circulation line 4 to the floating separation tank 1.

Further, the flotation / separation apparatus 100 includes a sludge extraction line 6 for extracting sludge deposited on the bottom of the flotation / separation tank 1, a sludge extraction valve 7 for opening / closing the sludge extraction line 6, and the flotation / separation tank 1 A floating sludge discharge port 8 for discharging the floating sludge Y adsorbed by the fine bubbles X on the surface of the treatment liquid and floating, and a floating sludge tank 9 for storing the floating sludge Y discharged from the floating sludge discharge port 8. In order to form fine bubbles in the fine bubble formation pump 5, and a fine bubble discharge port 10 for discharging the treatment liquid containing the fine bubbles formed by the fine bubble formation pump 5 into the treatment liquid in the floating separation tank 1. Air intake line 11 for inhaling air
And have.

Further, the levitation separating apparatus 100 includes two ultrasonic vibrators 21 for irradiating ultrasonic waves from the bottom of the levitation separating tank 1 into the processing liquid, and ultrasonic waves for vibrating the ultrasonic vibrators 21. A power source 22 and an ultrasonic power cable 23 that electrically connects the ultrasonic transducer 21 and the ultrasonic power source 22 are provided.

The floating separation tank 1 has a cylindrical shape with a circular cross section, and has a conical shape so that sludge accumulated at the bottom can be easily extracted. The treatment liquid feeding line 2 supplies a treatment liquid such as waste water into the floating separation tank 1 according to an instruction from a control unit (not shown). The discharge line 3 sends the processing liquid, for which the floating separation processing has been completed, to the next processing device (not shown) in accordance with an instruction from a control unit (not shown). The discharge line 3 and the circulation line 4 discharge the processing liquid from the floating separation tank 1 and take out a part of the processing liquid in order to generate the fine bubbles X according to an instruction from a control unit (not shown). The fine bubble formation pump 5 mixes the air sucked from the air suction line 11 with the treatment liquid taken out from the circulation line 4 according to an instruction from a control unit (not shown), pressurizes it, and then depressurizes it. The air component is generated as fine bubbles. The fine bubble forming pump X preferably forms ultra fine bubbles having a diameter of several microns to several tens of microns. This ultrafine bubble
The bubbles have a floating speed of 1 [mm / s] or less when only buoyancy is applied.

The sludge removal line 6 removes the sludge accumulated at the bottom from the inside of the flotation / separation tank 1 according to an instruction from a control unit (not shown). In addition, a part of the extracted processing liquid may be returned to the processing liquid input line 2 side again. The sludge extraction valve 7 opens and closes according to an instruction from a control unit (not shown) to extract the sludge. The floating sludge discharge port 8 is opened and closed according to an instruction from a control unit (not shown) to discharge the floating sludge Y to the floating sludge tank 9. In addition,
It is preferable that the floating separation tank 1 is provided with a sweeping mechanism (not shown) at the upper part so that the floating sludge Y can be swept out to the floating sludge discharge port 8 side. The floating sludge tank 9 discharges the floating sludge Y to a garbage dump when a certain amount of the floating sludge Y is accumulated. The fine bubble discharge port 10 is provided on the bottom side in the flotation separation tank 1 so that the fine bubbles can easily adsorb floating substances and dissolved components dispersed in the entire treatment liquid. The air suction line 11 is adapted to suck outside air.

The ultrasonic vibrator 21 is, for example, a piezoelectric element for generating ultrasonic waves by the piezoelectric effect or an element for generating ultrasonic waves by the magnetostrictive effect. In the former, when an AC voltage is applied, the ceramics is distorted at that frequency and ultrasonic vibrations are excited. Further, in the latter, when an alternating magnetic field is applied, the ceramics is distorted at that frequency and ultrasonic vibrations are excited. It should be noted that it is also possible to generate ultrasonic waves by a fusible sounding device using compressed air. In the following description, this ultrasonic transducer 21 is assumed to generate ultrasonic waves by the piezoelectric effect.

Further, the ultrasonic power source 22 supplies an AC voltage or an AC magnetic field for vibrating the ultrasonic vibrator 21 at a predetermined frequency through an ultrasonic power cable 23 to generate an ultrasonic wave. It is a means. The ultrasonic power source 22 adjusts the magnitude of the AC voltage and the AC magnetic field, the application timing, and the like. For example, this ultrasonic power source 22
Supplies power so that the ultrasonic transducer 21 irradiates ultrasonic waves while supplying the minute bubbles X from the minute bubble emitting port 10. Further, the ultrasonic power source 22 supplies power so that the ultrasonic oscillator 21 irradiates ultrasonic waves after stopping the supply of the fine bubbles X from the fine bubble discharge port 10. further,
The ultrasonic power source 22 supplies power so that the ultrasonic transducer 21 intermittently irradiates ultrasonic waves at predetermined intervals. Also, the setting of the magnitude of AC voltage and AC magnetic field and the application timing is
The operator may perform each time, or may set it in the apparatus itself in advance.

In the levitation separation apparatus 100, the treatment liquid is continuously supplied to the levitation separation tank 1 from the treatment liquid charging line 2. Next, the fine bubbles X are discharged from the fine bubble discharge port 10 into the treatment liquid in the floating separation tank 1 by the fine bubbles X formed by the fine bubble forming pump 5. Then, the fine bubbles X adsorb floating substances and dissolved components in the treatment liquid while floating by the buoyancy.

Then, after a sufficient time has passed for the fine bubbles X to adsorb the suspended substances and dissolved components in the treatment liquid,
The ultrasonic transducer 21 generates ultrasonic waves by the AC voltage applied by the ultrasonic power source 22. Then, the fine bubbles X are
It is pushed up by ultrasonic waves along with the buoyancy, and floats up and accumulates as floating sludge Y on the surface of the treatment liquid as bubbles. It should be noted that by generating ultrasonic waves during the supply of the fine bubbles X before the time sufficient for the fine bubbles X to adsorb the suspended substances and dissolved components in the treatment liquid, the fine bubbles X are removed. It is possible to shorten the time taken to spread the whole processing solution.
Further, by intermittently supplying ultrasonic waves, it is possible to alternately levitate by ultrasonic waves and adsorb floating substances or dissolved components.

After that, the floating sludge Y is discharged from the floating sludge discharge port 8
And is stored in the floating sludge tank 9.
The sludge that has settled is extracted from the sludge extraction line 6 by opening the sludge extraction valve 7. With this, the floating separation process is completed, and the processing liquid in the floating separation tank 1 is discharged from the discharge line 3 to the next processing device (not shown).

According to the first embodiment, since not only the buoyancy force that the fine bubbles receive from the treatment liquid but also the large acoustic pressure due to the ultrasonic waves is applied, it is faster than the floating only by the buoyancy force and the sound pressure greater than the buoyancy force. You will be able to push up. Therefore, the suspended solids or dissolved components in the treatment liquid adsorbed in the bubbles can be efficiently separated from the treatment liquid. Therefore, according to the levitation separation apparatus of the first embodiment, it is possible to shorten the time required for levitation separation and improve the levitation separation efficiency.

(Embodiment 2) FIG. 2 is a diagram for explaining the outline of a flotation device according to Embodiment 2 of the present invention. 20
Reference numeral 0 is a levitation separation device that floats bubbles by sound pressure due to ultrasonic waves and buoyancy received from the aqueous solution and separates suspended solids and dissolved components adsorbed by the bubbles from the aqueous solution. The levitation separation device 200 according to the second embodiment is different from the levitation separation device 100 in that the second ultrasonic transducer 24 is provided so that the levitation separation can be performed more efficiently.

The levitation separating apparatus 200 performs levitation separation treatment on the supplied aqueous solution to be treated (hereinafter referred to as "treatment liquid") to adsorb the substance to be separated in the treatment liquid to fine bubbles to cause levitation separation. Flotation separation tank 1, treatment liquid input line 2 for supplying treatment liquid into the floatation separation tank 1, discharge line 3 for discharging treatment liquid from the floatation separation tank 1, and treatment discharged from the discharge line 3. It has a circulation line 4 for circulating the liquid to the flotation separation tank 1 again, and a fine bubble formation pump 5 for forming fine bubbles in the treatment liquid circulating from the circulation line 4 to the flotation separation tank 1. .

The flotation / separation device 200 also includes a sludge extraction line 6 for extracting sludge settling at the bottom of the flotation / separation tank 1, a sludge extraction valve 7 for opening / closing the sludge extraction line 6, and the flotation / separation tank 1 A floating sludge discharge port 8 for discharging the floating sludge Y adsorbed by the fine bubbles X on the surface of the treatment liquid and floating, and a floating sludge tank 9 for storing the floating sludge Y discharged from the floating sludge discharge port 8. In order to form fine bubbles in the fine bubble formation pump 5, and a fine bubble discharge port 10 for discharging the treatment liquid containing the fine bubbles formed by the fine bubble formation pump 5 into the treatment liquid in the floating separation tank 1. Air intake line 11 for inhaling air
And have.

Further, the levitation separation apparatus 200 includes two ultrasonic vibrators 21 for irradiating ultrasonic waves from the bottom of the levitation separation tank 1 into the treatment liquid, and the middle stage of the levitation separation tank 1 into the treatment liquid. Two second ultrasonic transducers 24 for irradiating ultrasonic waves to the
An ultrasonic power source 22 for vibrating the ultrasonic oscillator 21 and the second ultrasonic oscillator 24; and an ultrasonic oscillator 2
1 and an ultrasonic power source 22 are electrically connected to each other, and an ultrasonic power cable 23 is provided. The second ultrasonic transducer 2
4 and the ultrasonic power source 22 are also electrically connected by an ultrasonic power cable (not shown).

The floating separation tank 1 has a cylindrical shape with a circular cross section, and has a conical shape so that sludge accumulated at the bottom can be easily extracted. The treatment liquid feeding line 2 supplies a treatment liquid such as waste water into the floating separation tank 1 according to an instruction from a control unit (not shown). The discharge line 3 sends the processing liquid, for which the floating separation processing has been completed, to the next processing device (not shown) in accordance with an instruction from a control unit (not shown). The discharge line 3 and the circulation line 4 discharge the processing liquid from the floating separation tank 1 and take out a part of the processing liquid in order to generate the fine bubbles X according to an instruction from a control unit (not shown). The fine bubble formation pump 5 mixes the air sucked from the air suction line 11 with the treatment liquid taken out from the circulation line 4 according to an instruction from a control unit (not shown), pressurizes it, and then depressurizes it. The air component is generated as fine bubbles. The fine bubble forming pump X preferably forms ultra fine bubbles having a diameter of several microns to several tens of microns. This ultrafine bubble
The bubbles have a floating speed of 1 [mm / s] or less when only buoyancy is applied.

The sludge removal line 6 removes the sludge accumulated at the bottom from the flotation / separation tank 1 according to an instruction from a control unit (not shown). In addition, a part of the extracted processing liquid may be returned to the processing liquid input line 2 side again. The sludge extraction valve 7 opens and closes according to an instruction from a control unit (not shown) to extract the sludge. The floating sludge discharge port 8 is opened and closed according to an instruction from a control unit (not shown) to discharge the floating sludge Y to the floating sludge tank 9. In addition,
It is preferable that the floating separation tank 1 is provided with a sweeping mechanism (not shown) at the upper part so that the floating sludge Y can be swept out to the floating sludge discharge port 8 side. The floating sludge tank 9 discharges the floating sludge Y to a garbage dump when a certain amount of the floating sludge Y is accumulated. The fine air bubble discharge port 10 is provided on the bottom side in the flotation tank 1 so that the fine air bubbles can easily adsorb floating substances or molten components dispersed in the entire processing liquid. The air suction line 11 is adapted to suck outside air.

The ultrasonic oscillator 21 and the second ultrasonic oscillator 24 are, for example, a piezoelectric element for generating ultrasonic waves by the piezoelectric effect or an element for generating ultrasonic waves by the magnetostrictive effect. In the former, when an AC voltage is applied, the ceramics is distorted at that frequency and ultrasonic vibrations are excited.
Further, in the latter, when an alternating magnetic field is applied, the ceramics is distorted at that frequency and ultrasonic vibrations are excited. It should be noted that it is also possible to generate ultrasonic waves by a fusible sounding device using compressed air. In the following description, the ultrasonic transducer 21 and the second ultrasonic transducer 24 are assumed to generate ultrasonic waves by the piezoelectric effect.

Further, the ultrasonic power source 22 supplies an ultrasonic power cable to the ultrasonic vibrator 21 with an AC voltage or an AC magnetic field for vibrating the ultrasonic vibrator 21 and the second ultrasonic vibrator 24 at a predetermined frequency. It is an ultrasonic wave generation means for controlling the generation of ultrasonic waves by supplying the ultrasonic wave through the reference numeral 23. The ultrasonic power source 22 adjusts the magnitude of the AC voltage and the AC magnetic field, the application timing, and the like. For example, this ultrasonic power source 22
Supplies power so that the ultrasonic oscillator 21 and the second ultrasonic oscillator 24 irradiate ultrasonic waves while the fine bubble X is being supplied from the fine bubble discharge port 10. Also, this ultrasonic power source 2
2 supplies power so that the ultrasonic oscillator 21 and the second ultrasonic oscillator 24 irradiate ultrasonic waves after stopping the supply of the fine bubbles X from the fine bubble discharge port 10. further,
The ultrasonic power source 22 supplies power so that the ultrasonic transducer 21 and the second ultrasonic transducer 24 intermittently emit ultrasonic waves at predetermined intervals. The magnitude of the AC voltage or the AC magnetic field and the application timing may be set by the operator each time, or may be set in the apparatus itself in advance.

In the levitation separation apparatus 200, the treatment liquid is continuously supplied to the levitation separation tank 1 from the treatment liquid feeding line 2. Next, the fine bubbles X are discharged from the fine bubble discharge port 10 into the treatment liquid in the floating separation tank 1 by the fine bubbles X formed by the fine bubble forming pump 5. Then, the fine bubbles X adsorb floating substances and dissolved components in the treatment liquid while floating by the buoyancy.

Then, after a sufficient time has passed for the fine bubbles X to adsorb the suspended substances and dissolved components in the treatment liquid,
The ultrasonic oscillator 21 and the second ultrasonic oscillator 24 generate ultrasonic waves by the AC voltage applied by the ultrasonic power source 22. Then, the fine bubbles X are pushed up by the ultrasonic waves together with the buoyancy, and float up and accumulate as the floating sludge Y on the surface of the treatment liquid as bubbles. It should be noted that by generating ultrasonic waves during the supply of the fine bubbles X before the time sufficient for the fine bubbles X to adsorb the suspended substances and dissolved components in the treatment liquid, the fine bubbles X are removed. It is possible to shorten the time taken to spread the whole processing solution. Further, by intermittently supplying ultrasonic waves, it is possible to alternately levitate by ultrasonic waves and adsorb floating substances or dissolved components.

Thereafter, the floating sludge Y is discharged from the floating sludge discharge port 8
And is stored in the floating sludge tank 9.
The sludge that has settled is extracted from the sludge extraction line 6 by opening the sludge extraction valve 7. With this, the floating separation process is completed, and the processing liquid in the floating separation tank 1 is discharged from the discharge line 3 to the next processing device (not shown).

According to the second embodiment, since not only the buoyancy force received from the treatment liquid by the microbubbles but also the large acoustic pressure due to the ultrasonic waves is applied, it is faster than the buoyancy force alone causes the surface to rise, and the sonic force larger than the buoyancy force causes the sound pressure to rise. You will be able to push up. Therefore, the suspended matter and dissolved components in the treatment liquid adsorbed in the bubbles can be efficiently separated from the treatment liquid. Further, since the second ultrasonic transducer is installed in the middle stage of the flotation tank, the fine bubbles near the middle stage can be efficiently levitated. You will be able to float the bubbles. Therefore, according to the levitation separation device of the second embodiment, it is possible to shorten the time required for levitation separation and improve the levitation separation efficiency.

(Embodiment 3) FIG. 3 is a diagram for explaining the outline of a floating separation device according to Embodiment 3 of the present invention. Thirty
Reference numeral 0 is a levitation separation device that floats bubbles by sound pressure due to ultrasonic waves and buoyancy received from the aqueous solution and separates suspended solids and dissolved components adsorbed by the bubbles from the aqueous solution. The levitation separation device 300 of the third embodiment is different from the levitation separation device 100 or 200 in that it is a fine bubble generation means for generating fine bubbles inside the levitation separation tank 1.

The flotation / separation apparatus 300 is a flotation / separation tank for subjecting an aqueous solution to be treated (hereinafter referred to as a “treatment liquid”) to a flotation separation treatment so that the separation target substance in the treatment liquid is adsorbed by fine bubbles to be floated and separated. 1, a treatment liquid charging line 2 for supplying a treatment liquid into the flotation separation tank 1, a discharge line 3 for discharging the treatment liquid from the flotation separation tank 1, and a sludge settling on the bottom of the flotation separation tank 1. A sludge extraction line 6 to be extracted, a sludge extraction valve 7 for opening and closing the sludge extraction line 6, and a floating sludge for discharging the floating sludge Y adsorbed by the fine bubbles X on the water surface of the treatment liquid in the flotation separation tank 1. It has a discharge port 8 and a floating sludge tank 9 for storing the floating sludge Y discharged from the floating sludge discharge port 8.

Further, the levitation separation apparatus 300 includes two ultrasonic vibrators 21 for irradiating ultrasonic waves from the bottom of the levitation separation tank 1 into the processing liquid, and ultrasonic waves for vibrating the ultrasonic vibrators 21. A power source 22, an ultrasonic power cable 23 for electrically connecting the ultrasonic transducer 21 and the ultrasonic power source 22,
A pair of electrode plates 31 for generating bubbles from the bottom side of the levitation separation tank 1, a DC power supply 32 for supplying a DC voltage to the electrode plates 31, and an electrode plate 31 and a DC power supply 32 are electrically connected. And a power supply line 33 that is electrically connected.

The floating separation tank 1 has a cylindrical shape with a circular cross section, and has a conical shape so that sludge accumulated at the bottom can be easily extracted. The treatment liquid feeding line 2 supplies a treatment liquid such as waste water into the floating separation tank 1 according to an instruction from a control unit (not shown). The discharge line 3 sends the processing liquid, for which the floating separation processing has been completed, to the next processing device (not shown) in accordance with an instruction from a control unit (not shown). The sludge removal line 6 removes sludge accumulated at the bottom from the flotation / separation tank 1 according to an instruction from a control unit (not shown).
In addition, a part of the extracted processing liquid may be returned to the processing liquid input line 2 side again. The sludge extraction valve 7 opens and closes according to an instruction from a control unit (not shown) to extract the sludge. The floating sludge discharge port 8 is opened and closed according to an instruction from a control unit (not shown) to discharge the floating sludge Y to the floating sludge tank 9. In addition, it is preferable that the floating separation tank 1 is provided with a sweeping mechanism (not shown) in the upper part so as to sweep the floating sludge Y toward the floating sludge discharge port 8 side. The floating sludge tank 9 discharges the floating sludge Y to a garbage dump when a certain amount of the floating sludge Y is accumulated.

The ultrasonic vibrator 21 is, for example, a piezoelectric element that generates ultrasonic waves by the piezoelectric effect or an element that generates ultrasonic waves by the magnetostrictive effect. In the former, when an AC voltage is applied, the ceramics is distorted at that frequency and ultrasonic vibrations are excited. Further, in the latter, when an alternating magnetic field is applied, the ceramics is distorted at that frequency and ultrasonic vibrations are excited. It should be noted that it is also possible to generate ultrasonic waves by a fusible sounding device using compressed air. In the following description, this ultrasonic transducer 21 is assumed to generate ultrasonic waves by the piezoelectric effect.

The ultrasonic power source 22 supplies an AC voltage or an AC magnetic field for vibrating the ultrasonic vibrator 21 at a predetermined frequency through the ultrasonic power cable 23 to generate ultrasonic waves. It is a means. The ultrasonic power source 22 adjusts the magnitude of the AC voltage and the AC magnetic field, the application timing, and the like. For example, this ultrasonic power source 22
Supplies power so that the ultrasonic transducer 21 irradiates ultrasonic waves while supplying the minute bubbles X from the minute bubble emitting port 10. Further, the ultrasonic power source 22 supplies power so that the ultrasonic oscillator 21 irradiates ultrasonic waves after stopping the supply of the fine bubbles X from the fine bubble discharge port 10. further,
The ultrasonic power source 22 supplies power so that the ultrasonic transducer 21 intermittently irradiates ultrasonic waves at predetermined intervals. Also, the setting of the magnitude of AC voltage and AC magnetic field and the application timing is
The operator may perform each time, or may set it in the apparatus itself in advance.

A DC voltage is applied between the two electrode plates 31 by a DC power supply 32 through a power supply line 33 to generate fine bubbles X by electrolysis. The fine bubbles X preferably form ultrafine bubbles having a diameter of several microns to several tens of microns. The ultrafine bubbles are bubbles having a floating speed of 1 [mm / s] or less when only buoyancy is applied.

In the flotation / separation device 300, the treatment liquid is continuously supplied to the flotation / separation tank 1 from the treatment liquid charging line 2. Next, the fine bubbles X are generated when a DC voltage is applied between the electrode plates 31 by the DC power supply 32. Then, the fine bubbles X adsorb floating substances and dissolved components in the treatment liquid while floating by the buoyancy.

Then, after a sufficient time has passed for the fine bubbles X to adsorb the suspended substances and dissolved components in the treatment liquid,
The ultrasonic transducer 21 generates ultrasonic waves by the AC voltage applied by the ultrasonic power source 22. Then, the fine bubbles X are
It is pushed up by ultrasonic waves along with the buoyancy, and floats up and accumulates as floating sludge Y on the surface of the treatment liquid as bubbles. It should be noted that by generating ultrasonic waves during the supply of the fine bubbles X before the time sufficient for the fine bubbles X to adsorb the suspended substances and dissolved components in the treatment liquid, the fine bubbles X are removed. It is possible to shorten the time taken to spread the whole processing solution.
Further, by intermittently supplying ultrasonic waves, it is possible to alternately levitate by ultrasonic waves and adsorb floating substances or dissolved components.

Thereafter, the floating sludge Y is discharged from the floating sludge discharge port 8
And is stored in the floating sludge tank 9.
The sludge that has settled is extracted from the sludge extraction line 6 by opening the sludge extraction valve 7. With this, the floating separation process is completed, and the processing liquid in the floating separation tank 1 is discharged from the discharge line 3 to the next processing device (not shown).

According to the third embodiment, since not only the buoyancy force received from the processing liquid by the treatment liquid but also the large acoustic pressure due to the ultrasonic wave is applied, it is faster than the buoyancy force alone causes the surface to float, and the sonic force greater than the buoyancy force causes the fine air bubbles to rise. You will be able to push up. Therefore, the suspended matter and the dissolved components in the treatment liquid adsorbed in the bubbles can be efficiently separated from the treatment liquid. Therefore, according to the levitation separation apparatus of the third embodiment, it is possible to shorten the time required for levitation separation and increase the levitation separation efficiency.

(Embodiment 4) FIG. 4 is a diagram for explaining the outline of a flotation device according to Embodiment 4 of the present invention. 40
Reference numeral 0 is a levitation separation device that floats bubbles by sound pressure due to ultrasonic waves and buoyancy received from the aqueous solution and separates suspended solids and dissolved components adsorbed by the bubbles from the aqueous solution. This levitation separation device 400 is the levitation separation device 1
Compared with No. 00, the fine bubble generating means for generating fine bubbles is different.

This levitation separation device 400 is a levitation separation tank for subjecting an aqueous solution to be treated (hereinafter referred to as "treatment liquid") to levitation separation treatment so that the separation target substance in the treatment liquid is adsorbed by fine bubbles and levitation-separated. 1, a treatment liquid introduction line 2 for supplying a treatment liquid into the floating separation tank 1, a discharge line 3 for discharging the treatment liquid from the floating separation tank 1, and a treatment liquid discharged from the discharge line 3 again. It has a circulation line 4 for circulating it to the floating separation tank 1.

The flotation / separation device 400 further comprises a sludge extraction line 6 for extracting sludge settling on the bottom of the flotation / separation tank 1, a sludge extraction valve 7 for opening / closing the sludge extraction line 6, and the flotation / separation tank 1 A floating sludge discharge port 8 for discharging the floating sludge Y adsorbed by the fine bubbles X on the surface of the treatment liquid and floating, and a floating sludge tank 9 for storing the floating sludge Y discharged from the floating sludge discharge port 8. It has a fine bubble discharge port 10 for discharging the treatment liquid containing fine bubbles formed by the fine bubble formation pump 5 into the treatment liquid in the floating separation tank 1.

Further, the levitation separating apparatus 400 includes two ultrasonic vibrators 21 for irradiating ultrasonic waves from the bottom of the levitation separating tank 1 into the processing liquid, and ultrasonic waves for vibrating the ultrasonic vibrators 21. A power source 22, an ultrasonic power cable 23 for electrically connecting the ultrasonic transducer 21 and the ultrasonic power source 22,
A buffer tank 41 that dissolves pressurized air, a pressure adjustment valve 42 that adjusts the pressure of the processing liquid flowing from the buffer tank 41 to release it from the fine bubble discharge port 10, and a buffer tank 41 and pressure adjustment from the circulation line 4. A circulation pump 44 that circulates the treatment liquid through the floating separation tank 1 via a valve 42.

The floating separation tank 1 has a cylindrical shape with a circular cross section, and has a conical shape so that sludge accumulated at the bottom can be easily extracted. The treatment liquid feeding line 2 supplies a treatment liquid such as waste water into the floating separation tank 1 according to an instruction from a control unit (not shown). The discharge line 3 sends the processing liquid, for which the floating separation processing has been completed, to the next processing device (not shown) in accordance with an instruction from a control unit (not shown). The discharge line 3 and the circulation line 4 discharge the processing liquid from the floating separation tank 1 and take out a part of the processing liquid in order to generate the fine bubbles X according to an instruction from a control unit (not shown).

The sludge removal line 6 removes the sludge accumulated at the bottom from the inside of the flotation / separation tank 1 according to an instruction from a control unit (not shown). In addition, a part of the extracted processing liquid may be returned to the processing liquid input line 2 side again. The sludge extraction valve 7 opens and closes according to an instruction from a control unit (not shown) to extract the sludge. The floating sludge discharge port 8 is opened and closed according to an instruction from a control unit (not shown) to discharge the floating sludge Y to the floating sludge tank 9. In addition,
It is preferable that the floating separation tank 1 is provided with a sweeping mechanism (not shown) at the upper part so that the floating sludge Y can be swept out to the floating sludge discharge port 8 side. The floating sludge tank 9 discharges the floating sludge Y to a garbage dump when a certain amount of the floating sludge Y is accumulated. The fine air bubble discharge port 10 is provided on the bottom side in the flotation tank 1 so that the fine air bubbles can easily adsorb floating substances or molten components dispersed in the entire processing liquid.

The ultrasonic vibrator 21 is, for example, a piezoelectric element which generates ultrasonic waves by the piezoelectric effect or an element which generates ultrasonic waves by the magnetostrictive effect. In the former, when an AC voltage is applied, the ceramics is distorted at that frequency and ultrasonic vibrations are excited. Further, in the latter, when an alternating magnetic field is applied, the ceramics is distorted at that frequency and ultrasonic vibrations are excited. It should be noted that it is also possible to generate ultrasonic waves by a fusible sounding device using compressed air. In the following description, this ultrasonic transducer 21 is assumed to generate ultrasonic waves by the piezoelectric effect.

The ultrasonic power source 22 supplies an AC voltage or an AC magnetic field for vibrating the ultrasonic vibrator 21 at a predetermined frequency through an ultrasonic power cable 23 to generate ultrasonic waves. It is a means. The ultrasonic power source 22 adjusts the magnitude of the AC voltage and the AC magnetic field, the application timing, and the like. For example, this ultrasonic power source 22
Supplies power so that the ultrasonic transducer 21 irradiates ultrasonic waves while supplying the minute bubbles X from the minute bubble emitting port 10. Further, the ultrasonic power source 22 supplies power so that the ultrasonic oscillator 21 irradiates ultrasonic waves after stopping the supply of the fine bubbles X from the fine bubble discharge port 10. further,
The ultrasonic power source 22 supplies power so that the ultrasonic transducer 21 intermittently irradiates ultrasonic waves at predetermined intervals. Also, the setting of the magnitude of AC voltage and AC magnetic field and the application timing is
The operator may perform each time, or may set it in the apparatus itself in advance.

The buffer tank 41 is a tank for dissolving pressurized air in the processing liquid under a predetermined pressure. When the treatment liquid is supplied to the floating separation tank, it returns to normal pressure (atmospheric pressure), and thus supersaturated air is deposited as fine bubbles. It is preferable that the fine bubbles form ultrafine bubbles having a diameter of about several microns to several tens of microns. The ultrafine bubbles are bubbles having a floating speed of 1 [mm / s] or less when only buoyancy is applied.

In the flotation / separation device 400, the treatment liquid is continuously supplied to the flotation / separation tank 1 from the treatment liquid feeding line 2. Next, the treatment liquid in which the pressurized air is dissolved in the buffer tank 41 is supplied to the floating separation tank 1 through the circulation pump 44. At that time, the treatment liquid returns to normal pressure, and the supersaturated air is deposited as fine bubbles X. And fine bubbles X
Are discharged from the fine bubble discharge port 10. Then, the fine bubbles X adsorb floating substances and dissolved components in the treatment liquid while floating by the buoyancy.

Then, after a sufficient time has elapsed for the fine bubbles X to adsorb the suspended substances and dissolved components in the treatment liquid,
The ultrasonic transducer 21 generates ultrasonic waves by the AC voltage applied by the ultrasonic power source 22. Then, the fine bubbles X are
It is pushed up by ultrasonic waves along with the buoyancy, and floats up and accumulates as floating sludge Y on the surface of the treatment liquid as bubbles. It should be noted that by generating ultrasonic waves during the supply of the fine bubbles X before the time sufficient for the fine bubbles X to adsorb the suspended substances and dissolved components in the treatment liquid, the fine bubbles X are removed. It is possible to shorten the time taken to spread the whole processing solution.
Further, by intermittently supplying ultrasonic waves, it is possible to alternately levitate by ultrasonic waves and adsorb floating substances or dissolved components.

Thereafter, the floating sludge Y is discharged from the floating sludge discharge port 8
And is stored in the floating sludge tank 9.
The sludge that has settled is extracted from the sludge extraction line 6 by opening the sludge extraction valve 7. With this, the floating separation process is completed, and the processing liquid in the floating separation tank 1 is discharged from the discharge line 3 to the next processing device (not shown).

According to the fourth embodiment, since not only the buoyancy force received from the treatment liquid by the treatment liquid but also the large acoustic pressure due to the ultrasonic waves is applied, it is faster than the buoyancy force alone causes the surface to rise, and the sonic force greater than the buoyancy force causes the fine bubbles to rise. You will be able to push up. Therefore, the suspended matter and dissolved components in the treatment liquid adsorbed in the bubbles can be efficiently separated from the treatment liquid. Further, the bubble diameter can be easily adjusted by controlling the pressure in the buffer tank.
Therefore, according to the levitation separation apparatus of the fourth embodiment, it is possible to shorten the time required for levitation separation and increase the levitation separation efficiency.

(Fifth Embodiment) FIG. 5 is a view for explaining the outline of a floating separation device according to a fifth embodiment of the present invention. Fifty
Reference numeral 0 is a levitation separation device that floats bubbles by sound pressure due to ultrasonic waves and buoyancy received from the aqueous solution and separates suspended solids and dissolved components adsorbed by the bubbles from the aqueous solution. The floating separation device 500 is the same as the floating separation device 4 described above.
Compared with No. 00, the fine bubble generating means for generating fine bubbles is different.

The levitation separation apparatus 500 is a levitation separation tank in which an aqueous solution to be treated (hereinafter referred to as "treatment liquid") is subjected to levitation separation treatment so that a substance to be separated in the treatment liquid is adsorbed by fine bubbles to be levitation-separated. 1, a treatment liquid introduction line 2 for supplying a treatment liquid into the floating separation tank 1, a discharge line 3 for discharging the treatment liquid from the floating separation tank 1, and a treatment liquid discharged from the discharge line 3 again. It has a circulation line 4 for circulating it to the floating separation tank 1.

The flotation / separation device 500 also includes a sludge extraction line 6 for extracting sludge settling at the bottom of the flotation / separation tank 1, a sludge extraction valve 7 for opening / closing the sludge extraction line 6, and the flotation / separation tank 1 A floating sludge discharge port 8 for discharging the floating sludge Y adsorbed by the fine bubbles X on the surface of the treatment liquid and floating, and a floating sludge tank 9 for storing the floating sludge Y discharged from the floating sludge discharge port 8. It has a fine bubble discharge port 10 for discharging the treatment liquid containing fine bubbles formed by the fine bubble formation pump 5 into the treatment liquid in the floating separation tank 1.

Further, the levitation separation device 500 is composed of two ultrasonic vibrators 21 for irradiating ultrasonic waves from the bottom of the levitation separation tank 1 into the processing liquid, and ultrasonic waves for vibrating the ultrasonic vibrators 21. A power source 22, an ultrasonic power cable 23 for electrically connecting the ultrasonic transducer 21 and the ultrasonic power source 22,
A buffer tank 41 in which two electrode plates 43 that generate fine bubbles are arranged, a pressure adjusting valve 42 that adjusts the pressure of the processing liquid flowing from the buffer tank 41 and discharges it from the fine bubble discharge port 10, and the circulation line. 4 through the buffer tank 41 and the pressure adjusting valve 42
And a circulation pump 44 for circulating the processing liquid.

The floating separation tank 1 has a cylindrical shape with a circular cross section, and has a conical shape so that sludge accumulated at the bottom can be easily extracted. The treatment liquid feeding line 2 supplies a treatment liquid such as waste water into the floating separation tank 1 according to an instruction from a control unit (not shown). The discharge line 3 sends the processing liquid, for which the floating separation processing has been completed, to the next processing device (not shown) in accordance with an instruction from a control unit (not shown). The discharge line 3 and the circulation line 4 discharge the processing liquid from the floating separation tank 1 and take out a part of the processing liquid in order to generate the fine bubbles X according to an instruction from a control unit (not shown).

The sludge removal line 6 removes the sludge accumulated at the bottom from the inside of the flotation / separation tank 1 according to an instruction from a control unit (not shown). In addition, a part of the extracted processing liquid may be returned to the processing liquid input line 2 side again. The sludge extraction valve 7 opens and closes according to an instruction from a control unit (not shown) to extract the sludge. The floating sludge discharge port 8 is opened and closed according to an instruction from a control unit (not shown) to discharge the floating sludge Y to the floating sludge tank 9. In addition,
It is preferable that the floating separation tank 1 is provided with a sweeping mechanism (not shown) at the upper part so that the floating sludge Y can be swept out to the floating sludge discharge port 8 side. The floating sludge tank 9 discharges the floating sludge Y to a garbage dump when a certain amount of the floating sludge Y is accumulated. The fine air bubble discharge port 10 is provided on the bottom side in the flotation tank 1 so that the fine air bubbles can easily adsorb floating substances or molten components dispersed in the entire processing liquid.

The ultrasonic vibrator 21 is, for example, a piezoelectric element which generates ultrasonic waves by the piezoelectric effect or an element which generates ultrasonic waves by the magnetostrictive effect. In the former, when an AC voltage is applied, the ceramics is distorted at that frequency and ultrasonic vibrations are excited. Further, in the latter, when an alternating magnetic field is applied, the ceramics is distorted at that frequency and ultrasonic vibrations are excited. It should be noted that it is also possible to generate ultrasonic waves by a fusible sounding device using compressed air. In the following description, this ultrasonic transducer 21 is assumed to generate ultrasonic waves by the piezoelectric effect.

Further, the ultrasonic power source 22 supplies an AC voltage or an AC magnetic field for vibrating the ultrasonic vibrator 21 at a predetermined frequency through an ultrasonic power cable 23 to generate an ultrasonic wave. It is a means. The ultrasonic power source 22 adjusts the magnitude of the AC voltage and the AC magnetic field, the application timing, and the like. For example, this ultrasonic power source 22
Supplies power so that the ultrasonic transducer 21 irradiates ultrasonic waves while supplying the minute bubbles X from the minute bubble emitting port 10. Further, the ultrasonic power source 22 supplies power so that the ultrasonic oscillator 21 irradiates ultrasonic waves after stopping the supply of the fine bubbles X from the fine bubble discharge port 10. further,
The ultrasonic power source 22 supplies power so that the ultrasonic transducer 21 intermittently irradiates ultrasonic waves at predetermined intervals. The operator may set the magnitude of the AC voltage or the AC magnetic field and the application timing each time, or may be set in the apparatus itself in advance.

The buffer tank 41 is a tank for dissolving pressurized air in the processing liquid under a predetermined pressure. When the treatment liquid is supplied to the floating separation tank, it returns to normal pressure (atmospheric pressure), and thus supersaturated air is deposited as fine bubbles. Further, two electrode plates 43 are arranged in this buffer tank 41. The electrode plate 43 is electrically connected to a DC power source (not shown). This electrode plate 43
Generates bubbles by electrolysis when the pressurized air is dissolved in the buffer tank 41 as described above. The bubbles are discharged from the fine bubble discharge port 10 as fine bubbles when the pressure is reduced by passing through the pressure control valve 42. Since the electrode plate 43 is electrolyzed in the treatment liquid having a high pressure, sufficient bubbles can be generated even with a small surface area. The fine bubbles X preferably form ultrafine bubbles having a diameter of several microns to several tens of microns.
This ultra-fine bubble is 1 [mm / mm when only buoyancy is applied.
s] is a bubble having a floating speed of the following. Further, air may be sucked into the buffer tank 41 before pressurization.

In the flotation separation apparatus 500, the treatment liquid is fed from the treatment liquid feed line 2 by the volume of the flotation separation tank 1. Next, the treatment liquid in which the pressurized air is dissolved in the buffer tank 41 is supplied to the floating separation tank 1 through the circulation pump 44. When voltage is applied to the electrode plate 43 when the pressurized air melts, electrolysis occurs in the buffer tank 41.
Then, fine bubbles X are generated near the electrode plate 43. Then, when the treatment liquid is supplied to the floating separation tank 1, the treatment liquid returns to normal pressure, and the supersaturated air is deposited as fine bubbles X. Then, the fine bubbles X are discharged from the fine bubble discharge port 10. Then, the fine bubbles X adsorb floating substances and dissolved components in the treatment liquid while floating by the buoyancy.

Then, after a time sufficient for the fine bubbles X to adsorb the suspended substances and dissolved components in the treatment liquid,
The ultrasonic transducer 21 generates ultrasonic waves by the AC voltage applied by the ultrasonic power source 22. Then, the fine bubbles X are
It is pushed up by ultrasonic waves along with the buoyancy, and floats up and accumulates as floating sludge Y on the surface of the treatment liquid as bubbles. It should be noted that by generating ultrasonic waves during the supply of the fine bubbles X before the time sufficient for the fine bubbles X to adsorb the suspended substances and dissolved components in the treatment liquid, the fine bubbles X are removed. It is possible to shorten the time taken to spread the whole processing solution.
Further, by intermittently supplying ultrasonic waves, it is possible to alternately levitate by ultrasonic waves and adsorb floating substances or dissolved components.

Thereafter, the floating sludge Y is discharged from the floating sludge discharge port 8
And is stored in the floating sludge tank 9.
The sludge that has settled is extracted from the sludge extraction line 6 by opening the sludge extraction valve 7. With this, the floating separation process is completed, and the processing liquid in the floating separation tank 1 is discharged from the discharge line 3 to the next processing device (not shown).

According to the fifth embodiment, not only the buoyancy force received by the treatment liquid from the treatment liquid but also the large acoustic pressure due to the ultrasonic waves is applied, so that it is faster than the floating force by the buoyancy force alone, and the acoustic pressure is larger than the buoyancy force. You will be able to push up. Therefore, the suspended matter and dissolved components in the treatment liquid adsorbed in the bubbles can be efficiently separated from the treatment liquid. Further, since the electrode plate electrolyzes the treatment liquid pressurized in the buffer tank, it is possible to easily generate fine bubbles. Therefore, according to the levitation separation apparatus of the fifth embodiment, it is possible to shorten the time required for levitation separation and improve the levitation separation efficiency.

[0109]

EXAMPLE An experiment was conducted under the following conditions using the floating separation device 100 of the first embodiment. The experimental condition is a case where fine bubbles are supplied for 2 minutes to the methane fermentation liquid as a treatment liquid, and subsequently, ultrasonic waves having a frequency of 972 [kHz] are irradiated for 1 minute. Note that ultrafine bubbles may be generated or stopped during the time when ultrasonic waves are being applied.
Further, the comparative example is a case where fine bubbles were supplied for 2 minutes to the methane fermentation liquid as the treatment liquid. In addition, S-TO
C (Suspended Total Organic)
Carbon) is the total organic carbon that floats.

[0110]

[Table 1]

In the first to fifth embodiments, the case where the ultrasonic transducer 21 is provided at the bottom of the levitation separation tank 1 has been described, but the inside of the levitation separation tank 1 can be irradiated with ultrasonic waves. As long as it is located at any place, it may be installed separately without being in close contact with the flotation separation tank 1. For example, the ultrasonic transducer 10 is used in the floating separation tank 1
You may make it provide so that an ultrasonic wave may be irradiated from above.

Further, in the first to fifth embodiments, the case where two ultrasonic transducers 21 are attached to the bottom of the flotation tank 1 has been described, but the number is not limited to two. ,
The number of sheets may be one or three or more. Further, the shape thereof may be any shape such as a rectangular shape and a circular shape, and when the floating separation tank 1 is cylindrical as in the first embodiment, it may be a ring shape or a fan shape. .

In the third to fifth embodiments, a second ultrasonic transducer may be provided as in the case of the second embodiment. Further, in the first to fifth embodiments, the case where the ultrasonic transducer is provided at the bottom or the middle stage of the flotation separation tank has been described, but the present invention is not limited to this, and the ultrasonic transducer may be provided at the top or the depth of the flotation separation tank. A plurality may be provided in the vertical direction.

Further, in the first, second, fourth, and fifth embodiments, the fine bubble discharge port 10 is provided on the bottom side, but it is preferable to provide a plurality of fine bubble discharge ports 10 on the middle stage and the upper side. With this configuration, it is possible to efficiently disperse the fine bubbles in the entire treatment liquid and to adsorb the suspended substances or dissolved components to the fine bubbles.

In the third embodiment, the electrode plate 31
Although it is provided on the bottom side, a plurality may be provided on the middle or upper side,
Further, a plate extending from the bottom side to the upper side may be used. With this configuration, it is possible to efficiently disperse the fine bubbles in the entire treatment liquid and to adsorb the suspended substances or dissolved components to the fine bubbles.

Further, in the first to fifth embodiments, the case where the ultrasonic power source 22 controls the ultrasonic wave generation has been described. However, the command is input from the outside to adjust the AC voltage and the AC magnetic field. You may

In the second embodiment, the case where the fine bubbles are supplied from the outside of the flotation / separation tank 1 through the fine bubble discharge port 10 has been described.
Similar to the case, the electrode plate may be provided and the fine bubbles may be generated by electrolysis.

[0118]

As described above, according to the floating separation method of the present invention, bubbles are supplied to the aqueous solution to be treated stored in the treatment tank, and the substance to be separated in the aqueous solution is adsorbed by the bubbles. Ultrasonic waves are radiated toward the aqueous solution and the bubbles, and the bubbles are floated from the aqueous solution because the bubbles are levitated by the sound pressure of the ultrasonic waves and the buoyancy received from the aqueous solution to separate the substance to be separated adsorbed in the bubbles from the aqueous solution. Not only the buoyancy received, but also a large sound pressure due to ultrasonic waves, so it is faster than floating only by buoyancy,
It has the effect of being pushed up by a sound pressure greater than buoyancy. Therefore, the substance to be separated in the aqueous solution to be treated adsorbed in the bubbles is promoted to float due to the buoyancy and the sound pressure, and is effectively separated from the aqueous solution.

According to the floating separation method according to the following invention,
Since the irradiation of ultrasonic waves is performed during the supply of bubbles,
Since the bubbles are pushed up by ultrasonic waves every time the bubbles are supplied,
Further, there is an effect that the separation work can be performed more quickly.

According to the floating separation method according to the following invention,
Since the ultrasonic waves are emitted after stopping the supply of the bubbles, the ultrasonic waves are emitted after the supply of the bubbles is stopped and the bubbles are floated, so that the bubbles surely adsorb and separate the substances to be separated. There is an effect that can.

According to the floating separation method according to the following invention,
Since ultrasonic waves are emitted intermittently at predetermined intervals, the bubbles adsorb the separation target substance when the ultrasonic waves are not irradiated, and the bubbles that securely adsorb the separation target substance float when the ultrasonic waves are irradiated. Therefore, the floating separation process can be efficiently performed.

According to the floating separation method according to the following invention,
Since the bubbles to be supplied are a plurality of bubbles including ultrafine bubbles having a diameter of several microns to several tens of microns, even if the bubbles are ultrafine bubbles having a diameter of several microns to several tens of microns, the sound pressure by ultrasonic waves causes Can be quickly raised,
The effect that the floating separation work can be performed quickly is achieved.

As described above, according to the flotation / separation device of the present invention, the treatment tank for storing the aqueous solution to be treated and the bubble generation for generating the bubbles for adsorbing the separation target substance in the aqueous solution in the treatment tank. Means, an ultrasonic transducer for generating ultrasonic waves to irradiate the aqueous solution and bubbles, and an ultrasonic wave generating means for controlling the generation of the ultrasonic waves, and sound pressure by the ultrasonic waves and buoyancy received from the aqueous solution. The bubbles are floated by and the substance to be separated adsorbed on the bubbles is separated from the aqueous solution. Therefore, the bubbles receive not only the buoyancy received from the aqueous solution but also a large sound pressure due to ultrasonic waves,
It will be faster than it will float by buoyancy alone, and will be pushed up by sound pressure greater than buoyancy. Therefore, the substance to be separated in the aqueous solution to be treated is adsorbed by the bubbles due to the buoyancy and the sound pressure, floats up, and is separated from the aqueous solution.

According to the flotation separation device according to the next invention,
Since the ultrasonic wave generating means irradiates ultrasonic waves during the supply of the bubbles, the ultrasonic waves push up the bubbles each time the bubbles are supplied, so that the separation work can be performed more quickly.

According to the levitation separating apparatus according to the next invention,
Since the ultrasonic wave generation means is configured to irradiate the ultrasonic wave after stopping the supply of the bubbles, the ultrasonic waves are irradiated to suspend the supply of the bubbles to levitate the bubbles, and the bubbles ensure the separation target substance. The effect of being able to be adsorbed and floated is exhibited.

According to the flotation separation device according to the next invention,
Since the ultrasonic wave generation means is adapted to intermittently irradiate ultrasonic waves at a predetermined interval, the bubbles adsorb the separation target substance when the ultrasonic wave is not radiated, and the separation target substance is radiated when the ultrasonic wave is radiated. The effect is that the bubbles that have been adsorbed can be floated up and the floating separation process can be efficiently performed.

According to the levitation separating apparatus of the following invention,
Since the ultrasonic vibrator is provided in the lower part of the processing tank, the bubbles in the lower part of the processing tank are also floated upward, and thus the effect of efficiently floating and separating the separation target substance in the aqueous solution in the lower part of the processing tank is obtained. Play.

According to the flotation separation device according to the next invention,
Since the ultrasonic transducer is provided in the middle stage of the processing tank, there is an effect that bubbles near the middle stage of the processing tank can be efficiently levitated. In particular, it is preferable to provide a plurality of ultrasonic transducers in the middle of the processing tank and the lower portion of the processing tank. In order to efficiently float the air bubbles near the middle stage of the processing tank,
Bubbles in the lower part of the processing tank can also be efficiently floated.

According to the flotation device according to the next invention,
Since the bubble generating means has a bubble forming pump that sucks air into the aqueous solution to generate bubbles, and an ejection port that ejects the aqueous solution containing the bubbles into the processing tank, the bubble forming pump is formed. The effect that the generated bubbles can be supplied from the ejection port into the processing tank is exerted.

According to the levitation separating apparatus according to the next invention,
The bubble generating means is disposed between the delivery pump for delivering the aqueous solution into the treatment tank, the jet port for ejecting the aqueous solution containing bubbles into the treatment tank, and the delivery pump and the jet port for adding the aqueous solution. Since it has the buffer tank which melt | dissolves pressurized air, it has the effect of being able to supply the bubble (especially super-fine bubble) which the buffer tank formed into an inside of a processing tank from a jet outlet. In particular, by controlling the pressure in the buffer tank, the bubble diameter can be adjusted and adjusted according to the dissolved component contained in the aqueous solution, so that there is an effect that bubbles can be stably generated.

According to the levitation separating apparatus of the following invention,
In the buffer tank, the aqueous solution in which pressurized air is dissolved is returned to normal pressure, and supersaturated air is generated as bubbles. Therefore, there is an effect that the air bubbles can adhere to the substance to be separated of the aqueous solution in the processing tank and float and separate.

According to the levitation separating apparatus of the following invention,
The buffer tank has two electrode plates and a power source for applying a voltage between the electrode plates, and bubbles are generated by electrolysis by applying a voltage between the electrode plates. It is possible to supply bubbles generated by electrolysis in the tank to the processing tank.

According to the levitation separating apparatus according to the next invention,
The buffer tank has two electrode plates and a power source for applying a voltage between the electrode plates, and dissolves pressurized air in an inflowing aqueous solution, and at the same time, applies electricity by applying a voltage between the electrode plates. Bubbles are generated by decomposition, and the pressurized aqueous solution is discharged to reduce the pressure to generate finer bubbles, so that it is possible to generate the required bubbles even with an electrode plate having a small surface area. An effect that ultrafine bubbles can be easily generated at the time of depressurization is exerted.

According to the levitation separating apparatus according to the next invention,
The bubble generating means further has a discharge line for discharging the aqueous solution from the inside of the treatment tank, and since the air is sucked into the aqueous solution discharged from the discharge line to generate bubbles, the aqueous solution in the treatment tank is discharged. Since it is not necessary to directly supply air bubbles to the treatment tank for reflux into the treatment tank and newly supply water containing air bubbles into the treatment tank, it is possible to reduce the cost.

According to the flotation device according to the next invention,
Since the jet port is provided in the lower portion of the treatment tank, bubbles are supplied from the lower portion of the treatment tank, so that the substance to be separated can be adsorbed by the bubbles over the entire aqueous solution in the treatment tank.

According to the levitation separating apparatus of the following invention,
The bubble generating means has two electrode plates installed in the processing tank, and a power source for applying a voltage between the electrode plates.
Since the bubbles are generated by the electrolysis by applying the voltage between the electrode plates, the bubbles can be generated by the electrolysis in the treatment tank, and it is not necessary to supply the bubbles from outside the treatment tank. Play.

According to the levitation separating apparatus of the following invention,
Since the electrode plate is provided in the lower portion of the treatment tank, bubbles are supplied from the lower portion of the treatment tank, so that the substance to be separated can be adsorbed by the bubbles over the entire aqueous solution in the treatment tank.

According to the levitation separating apparatus of the following invention,
Since the bubble generating means is configured to supply a plurality of bubbles including ultrafine bubbles having a diameter of several microns to tens of microns, even if the bubbles are ultrafine bubbles having a diameter of several microns to tens of microns, Since it is possible to quickly levitate by the sound pressure of the sound wave, it becomes possible to quickly perform the levitating separation work. For example, even if it takes several hours when the force acting on the ultrafine bubbles is only buoyancy, it is possible to perform the separation work in about several minutes by applying the sound pressure by the ultrasonic waves to the ultrafine bubbles. .

Therefore, according to the present invention, it is possible to provide a levitation separation method and a levitation separation device in which the levitation time is short and the levitation separation efficiency is good even if ultrafine bubbles are used.

[Brief description of drawings]

FIG. 1 is a diagram illustrating an outline of a flotation device according to a first embodiment of the present invention.

FIG. 2 is a diagram illustrating an outline of a flotation device according to a second embodiment of the present invention.

FIG. 3 is a diagram illustrating an outline of a flotation separation device according to a third embodiment of the present invention.

FIG. 4 is a diagram illustrating an outline of a flotation device according to a fourth embodiment of the present invention.

FIG. 5 is a diagram illustrating an outline of a flotation device according to a fifth embodiment of the present invention.

FIG. 6 is a graph showing the relationship between frequency and particle diameter, which represents the result of Equation 3.

FIG. 7 is a diagram illustrating the concept of the floating separation method of the present invention.

FIG. 8 is a diagram illustrating an outline of a conventional flotation device.

FIG. 9 is a diagram illustrating the concept of a conventional floating separation method.

[Explanation of symbols]

1 floating separation tank 2 Processing liquid input line 3 discharge lines 4 circulation lines 5 Micro bubble formation pump 6 lines 7 valves 8 Flotation sludge discharge port 9 Floating sludge tank 10 Micro bubble outlet 11 Air suction line 21 Ultrasonic transducer 22 Ultrasonic power supply 23 Ultrasonic power cable 24 Second ultrasonic transducer 31 electrode plate 32 DC power supply 33 power supply line 41 buffer tank 42 Pressure control valve 43 electrode plate 44 Circulation pump 100 flotation device 200 flotation device 300 Flotation device 400 flotation device 500 flotation device 600 flotation device

   ─────────────────────────────────────────────────── ─── Continued front page    (72) Inventor Ichiro Toyota             1-8-1 Sachiura, Kanazawa-ku, Yokohama             Industrial Technology Research Institute F-term (reference) 4D037 AA11 BA03 BA26 BB07 CA04                 4D061 DA08 DB20 EA02 EB01 EB04                       EB14 EB17 EB19 FA20

Claims (22)

[Claims] 1. An air bubble is supplied to an aqueous solution to be treated which flows into a treatment tank so that a substance to be separated in the aqueous solution is adsorbed by the air bubble, and an ultrasonic wave is radiated toward the aqueous solution and the air bubble. A levitation separation method characterized in that the levitation of bubbles is promoted by sound pressure to increase the efficiency of separating the substance to be separated adsorbed on the bubbles from the aqueous solution. 2. The floating separation method according to claim 1, wherein the irradiation of ultrasonic waves is performed during the supply of bubbles. 3. The floating separation method according to claim 1, wherein the ultrasonic wave is irradiated after the supply of the bubbles is stopped. 4. The floating separation method according to claim 1, wherein the ultrasonic wave is intermittently irradiated at a predetermined interval. 5. The floating separation method according to claim 1, wherein the supplied bubbles are a plurality of bubbles including ultrafine bubbles having a diameter of several microns to several tens of microns. . 6. A treatment tank for storing an aqueous solution to be treated, a bubble generating means for generating bubbles for adsorbing a substance to be separated in the aqueous solution in the treatment tank, and an ultrasonic wave for irradiating the aqueous solution and the bubbles. An ultrasonic oscillator for generating and an ultrasonic wave generating means for controlling the generation of the ultrasonic wave are provided, and the separation target substance adsorbed to the bubble is separated from the aqueous solution by promoting the floating of the bubble by the sound pressure of the ultrasonic wave. A flotation separation device characterized by improved efficiency. 7. The levitation separation device according to claim 6, wherein the ultrasonic wave generation means irradiates ultrasonic waves during the supply of bubbles. 8. The levitation separation device according to claim 6, wherein the ultrasonic wave generator irradiates the ultrasonic wave after stopping the supply of the bubbles. 9. The levitation separation device according to claim 6, wherein the ultrasonic wave generation means intermittently emits ultrasonic waves at predetermined intervals. 10. The levitation separation device according to claim 6, wherein the ultrasonic transducer is provided in a lower portion of the processing tank. 11. The levitation separation device according to claim 6, wherein the ultrasonic transducer is provided in the middle stage of the processing tank. 12. The bubble generating means comprises a bubble forming pump for sucking air into the aqueous solution to generate bubbles, and an ejection port for ejecting the aqueous solution containing the bubbles into the processing tank.
The levitation separation device according to any one of claims 6 to 11, further comprising: 13. The bubble generating means is disposed between the delivery pump for delivering the aqueous solution into the processing tank, the ejection port for ejecting the aqueous solution containing bubbles into the processing tank, and the delivery pump and the ejection port. And a buffer tank for dissolving bubbles in the aqueous solution.
The flotation separation device according to any one of 1. 14. The buffer tank according to claim 13, wherein pressurized air is dissolved in the aqueous solution and then depressurized to atmospheric pressure to generate supersaturated air components in the aqueous solution as bubbles during depressurization. Flotation device. 15. The buffer tank has two electrode plates and a power supply for applying a voltage between the electrode plates, and bubbles are generated by electrolysis by applying a voltage between the electrode plates. The flotation device according to claim 13, wherein 16. The buffer tank has two electrode plates and a power supply for applying a voltage between the electrode plates, and bubbles are generated by electrolysis by applying a voltage between the electrode plates. The levitation separation device according to claim 13, wherein the aqueous solution in which the pressurized air is dissolved flows out and is depressurized to atmospheric pressure to generate supersaturated air as fine bubbles. 17. The air bubble generating means further has a discharge line for discharging the aqueous solution from the inside of the processing tank, and air is sucked into the aqueous solution discharged from the discharge line to generate bubbles. The floating separation device according to any one of claims 12 to 16. 18. The flotation device according to claim 12, wherein the jet port is provided in a lower portion of the processing tank. 19. The air bubble generating means has two electrode plates installed in the processing tank and a power source for applying a voltage between the electrode plates, and a voltage is applied between the electrode plates. The levitation separation device according to claim 6, wherein bubbles are generated by electrolysis. 20. The flotation device according to claim 19, wherein the electrode plate is provided in a lower portion of the processing tank. 21. The air bubble generating means depressurizes the aqueous solution in the processing tank and then depressurizes the air solution to generate air components in the aqueous solution as bubbles during depressurization.
The levitation separation apparatus according to any one of 1 to 11. 22. The levitation apparatus according to claim 6, wherein the bubble generating means supplies a plurality of bubbles including ultrafine bubbles having a diameter of several microns to several tens of microns. Separation device.