JP2020014989A - Degassed fine bubble liquid generating device, degassed fine bubble liquid generating method, ultrasonic treatment device and ultrasonic treatment method - Google Patents

Abstract

To provide a degassed fine bubble liquid generating device degassing a treatment liquid and generating fine bubbles in the treatment liquid by an easier method.SOLUTION: A degassed fine bubble liquid generating device generating a degassed fine bubble liquid which is a treatment liquid being supplied to a treatment portion held with the treatment liquid treating a prescribed treatment to a treating object, being degassed and containing fine bubbles comprises: a circulation path drawing out the treatment liquid from the treatment portion and supplying the generated degassed fine bubble liquid to the treatment portion; a first pump being disposed on the circulation path, drawing out the treatment liquid from the treatment portion and having a total head of 15 m or more; and a second pump being disposed at the drawing-out side of the treatment liquid from the first pump on the circulation path, being operated so as to carry the treatment liquid to a reverse direction to the first pump liquid and having a total head of (the total head of the first pump-15) m or more and the total head of the first pump or less.SELECTED DRAWING: Figure 1A

Description

  The present invention relates to an apparatus for producing a degassed fine bubble liquid, a method for producing a degassed fine bubble liquid, an ultrasonic treatment apparatus, and an ultrasonic treatment method.

  Generally, in a manufacturing process of various metal bodies such as a steel plate and a steel pipe, in order to remove dirt, scale, etc. existing on the surface of the metal body, the metal body is immersed in a cleaning tank holding a chemical solution, a rinse, and the like. A cleaning treatment method for performing cleaning is widely adopted. Examples of a cleaning apparatus that performs such a cleaning method include a processing apparatus using a high-pressure airflow injection nozzle and an ultrasonic processing apparatus using ultrasonic waves.

  In such an ultrasonic processing apparatus using ultrasonic waves, deaeration is performed to improve ultrasonic wave propagation, and microbubbles serving as nuclei of cavitation are introduced to enhance cavitation action in ultrasonic cleaning. Ingenuity has been devised, for example. For example, as a method of performing deaeration, a deaeration method using a vacuum pump, a deaeration method using a hollow fiber membrane, a deaeration method using a throttle, and the like have been proposed. Further, as a method of introducing fine bubbles, for example, a method of making bubbles fine by high-speed swirling, a method of dissolving a gas under high-pressure supersaturation to generate fine bubbles when released, and the like have been proposed. However, the above-described degassing method and microbubble generation method each require a dedicated unit, and a device combining these methods is large and very expensive.

  Therefore, in recent years, studies have been made on an apparatus that integrates stable generation of fine bubbles and adjustment of the amount of dissolved gas (that is, degassing). For example, in Patent Document 1 below, a casing of an axial flow type pump has a main blade and a sub-blade opposite to the main blade, and air bubbles are suctioned by a vacuum pump from a hole formed in a wall surface. An apparatus for producing degassed water by doing so has been proposed.

JP-A-10-99847

  However, in the device proposed in Patent Document 1, since the main blade and the sub blade are mounted on the same rotating shaft, the rotation speeds of the main blade and the sub blade are the same, and the control of the deaeration level is performed. There was a problem that can not be done. Further, in addition to the axial flow pump having the two kinds of blades as described above, a separate vacuum pump is required, and the apparatus is large.

  Therefore, the present invention has been made in view of the above problems, and an object of the present invention is to provide a simpler method for degassing a processing liquid and generating fine bubbles in the processing liquid. It is an object of the present invention to provide a degassed fine bubble liquid production apparatus, a degassed fine bubble liquid production method, an ultrasonic treatment apparatus, and an ultrasonic treatment method, which can perform the following.

In order to solve the above-mentioned problems, the present inventors have conducted intensive studies, and as a result, circulating the processing liquid to a processing unit that holds a processing liquid for performing a predetermined processing on an object to be processed. After providing the path, the present inventors have conceived of installing two types of pumps exhibiting a predetermined total head in such a circulation path and operating the two types of pumps simultaneously. This makes it possible to more easily produce a degassed fine bubble liquid that is a processing liquid that is degassed and contains fine bubbles.
The gist of the present invention completed based on the above findings is as follows.

[1] A degassed fine bubble liquid, which is a degassed and contains fine bubbles, is supplied to a processing section in which a processing liquid for performing a predetermined processing on a processing target is held. A deaerated fine bubble liquid manufacturing apparatus, wherein a circulation path for circulating the processing liquid drawn from the processing section to the processing section, and provided on the circulation path, wherein the processing liquid is drawn from the processing section. A first pump that circulates the processing liquid to the processing unit and has a total head of 15 m or more; and a first pump that is provided on the circulation path on the drawing side of the processing liquid with respect to the first pump. And a second pump having a total head (total head of the first pump−15) m or more and equal to or less than the total head of the first pump, the second pump being operated to convey the processing liquid in the opposite direction to the first pump. 1 pump and the second pump By operating both of the pumps to reduce the pressure in the circulation path located between the first pump and the second pump, the processing liquid is degassed and the processing liquid is deaerated. An apparatus for producing a degassed fine bubble liquid, wherein fine bubbles are generated to be the degassed fine bubble liquid, and the obtained degassed fine bubble liquid is supplied to the processing section.
[2] The flow rate of the processing liquid and the first and second pumps are controlled by inverter-controlled independently of each other the rotation speed of the motor of the first pump and the rotation speed of the motor of the second pump. The deaerated fine bubble liquid producing apparatus according to [1], further comprising an adjusting mechanism that adjusts the pressure inside the circulation path located between the fine bubble liquid and the circulating path.
[3] The adjusting mechanism is configured to control the first pump so that the flow rate of the processing liquid in the circulation path during the production of the degassed fine bubble liquid is in a range of 0.05 to 5.00 m / sec. The deaerated fine bubble liquid producing apparatus according to [2], wherein the number of rotations of the motor and the number of rotations of the motor of the second pump are controlled.
[4] When the maximum discharge amount of the first pump is Q1 [L / min] and the maximum discharge amount of the second pump is Q2 [L / min], the maximum discharge amount of the first pump is The deaerated fine bubble liquid producing apparatus according to [2] or [3], wherein the ratio (Q2 / Q1) to the maximum discharge amount of the second pump is 0.5 or more and 1.0 or less.
[5] The volume of the circulation path located between the first pump and the second pump is set to 1 / 10,000 or more of the total volume of the circulation system including the processing unit and the entire circulation path. The deaerated fine bubble liquid producing apparatus according to any one of [1] to [4].
[6] When the total head of the first pump is L1 [m] and the total head of the second pump is L2 [m], the total head of the first pump and the total head of the second pump are set to L1 [m]. The deaerated fine bubble liquid production apparatus according to any one of [1] to [5], wherein the difference (L1−L2) is set to 5 m or more and 10 m or less.
[7] The fine bubbles are generated such that the dissolved gas amount is 50% or less of the saturated dissolved gas amount in the processing liquid discharged to the processing unit, any of [1] to [6]. The deaerated fine bubble liquid producing apparatus according to any one of the first to third aspects.
[8] In the processing liquid discharged to the processing unit, the fine bubbles having an average bubble diameter of 0.01 μm to 100 μm exist in a range of a total bubble amount of 10 ³ bubbles / mL to ¹⁰ 10 bubbles / mL. The degassed fine bubble liquid manufacturing apparatus according to any one of [1] to [7], wherein the fine bubbles are generated so as to generate the fine bubbles.
[9] A method for producing a degassed fine bubble liquid using the degassed fine bubble liquid producing apparatus according to any one of [1] to [8], wherein the first pump and the second pump are used. A deaerated fine bubble liquid producing method, comprising the steps of: deactivating the inside of the circulation path located between the first pump and the second pump;
[10] The degassed fine bubble according to [9], wherein the flow rate of the processing liquid in the circulation path is adjusted within a range of 0.05 to 5.00 m / sec in the degassing and fine bubble generation process. Liquid production method.
[11] The deaeration and fine bubble generation process, one of the first pump and the second pump is stopped, and the casings of the first and second pumps and the first pump are stopped. And a gas discharging step of discharging gas remaining in the circulation path located between the second pump and the second pump, wherein the gas discharging step is performed alternately. [9] or [10]. Method.
[12] The time per cycle of the degassing and fine bubble generation process is set to be within a range of 60 to 3600 seconds, and the time per cycle of the gas discharging process is set to be within a range of 1 to 60 seconds. The method for producing a degassed fine bubble liquid according to [11].
[13] A processing unit which holds a processing liquid for performing predetermined processing on the processing object, and is provided in the processing unit, wherein the processing object is filled with the processing liquid, and the processing unit An ultrasonic wave applying mechanism for applying ultrasonic waves, and an apparatus for producing a degassed fine bubble liquid according to any one of [1] to [8], provided for the processing unit. Processing equipment.
[14] A processing unit that holds a processing liquid for performing a predetermined process on the processing object, and is provided in the processing unit, where the processing object is filled with the processing liquid, and An ultrasonic wave applying mechanism for applying an ultrasonic wave by means of a deaerated fine bubble liquid manufacturing apparatus according to any one of [1] to [8], provided for the processing unit. An ultrasonic processing method performed by a processing apparatus, wherein both the first pump and the second pump are in an operating state, and the inside of the circulation path located between the first pump and the second pump. The degassing and fine bubble generation process of reducing the pressure to a reduced pressure state produces the degassed fine bubble liquid, and supplies the produced degassed fine bubble liquid to the processing section, while the ultra-fine processing is performed on the object to be processed. Apply ultrasonic wave from sound wave application mechanism That, ultrasonic processing method.
[15] The ultrasonic treatment method according to [14], wherein the flow rate of the treatment liquid in the circulation path is adjusted within a range of 0.05 to 5.00 m / sec in the degassing and fine bubble generation processes. .
[16] The deaeration and fine bubble generation process, one of the first pump and the second pump is stopped, the casings of the first pump and the second pump, and the first pump are stopped. And the gas discharge process of discharging gas remaining inside the circulation path located between the second pump and the second pump to produce the degassed fine bubble liquid by alternately performing [14] or The ultrasonic treatment method according to [15].
[17] The time per cycle of the degassing and fine bubble generation process is set to be within a range of 60 to 3600 seconds, and the time per cycle of the gas discharging process is set to be within a range of 1 to 60 seconds. The ultrasonic treatment method according to [16].

  As described above, according to the present invention, the processing liquid can be degassed and fine bubbles can be generated in the processing liquid by a simpler method.

BRIEF DESCRIPTION OF THE DRAWINGS It is explanatory drawing which showed typically the example of the structure of the deaerated fine bubble liquid manufacturing apparatus which concerns on embodiment of this invention, and the ultrasonic processing apparatus provided with the said deaerated fine bubble liquid manufacturing apparatus. It is explanatory drawing which showed typically an example of the structure of the deaerated fine bubble liquid manufacturing apparatus which concerns on the same embodiment, and the ultrasonic processing apparatus provided with the said deaerated fine bubble liquid manufacturing apparatus. It is explanatory drawing which showed typically the modification of the deaerated fine bubble liquid manufacturing apparatus which concerns on the same embodiment, and an example of the structure of the ultrasonic processing apparatus provided with the said deaerated fine bubble liquid manufacturing apparatus. FIG. 4 is an explanatory diagram for describing the degassed fine bubble liquid manufacturing method according to the embodiment;

  Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings. In the specification and the drawings, components having substantially the same function and configuration are denoted by the same reference numerals, and redundant description is omitted.

(Overall configuration of degassing fine bubble liquid production equipment and ultrasonic treatment equipment)
With reference to FIG. 1A and FIG. 1B, the degassing fine bubble liquid manufacturing apparatus according to the embodiment of the present invention and the entire configuration of an ultrasonic processing apparatus provided with the degassing fine bubble liquid manufacturing apparatus will be briefly described. explain. FIGS. 1A and 1B are explanatory views schematically showing an example of the configuration of a degassed fine bubble liquid production apparatus according to the present embodiment and an ultrasonic treatment apparatus provided with the degassed fine bubble liquid production apparatus. is there.

  The ultrasonic processing apparatus 1 provided with the degassed fine bubble liquid manufacturing apparatus 10 according to the present embodiment uses an ultrasonic wave in addition to a processing liquid for performing a predetermined processing on the object to be processed. This is an apparatus that performs a predetermined process on (a part in contact with the processing liquid). The ultrasonic processing apparatus 1 is used for performing various processes such as cleaning on various metal bodies typified by steel materials and the like and various nonmetal bodies typified by plastic resin members and the like. Can be used. For example, various metal bodies such as a steel plate, a steel pipe, and a steel wire are used as objects to be processed, and by using the ultrasonic treatment apparatus 1 according to the present embodiment, these metal bodies are subjected to pickling treatment, degreasing treatment, Further, a cleaning process can be performed.

  Here, the pickling treatment is a treatment for removing oxide scale formed on the surface of the metal body, and the degreasing treatment is a treatment for removing an oil component such as a lubricant or a processing oil used for the processing. is there. These pickling treatments and degreasing treatments are pretreatments that are performed prior to applying a surface finishing treatment (metal coating treatment, chemical conversion treatment, painting treatment, etc.) to the metal body. Such pickling may dissolve some of the ground metal. Such pickling treatment is also used for dissolving a metal body by etching to improve surface finish quality. In some cases, a degreasing treatment is provided before the pickling treatment, and the degreasing performance in the degreasing treatment may affect scale removal in the subsequent pickling treatment. Furthermore, the degreasing treatment is also used for improving the wettability, which is an index for controlling the oil content as the finish quality of the final product.

  Furthermore, the ultrasonic treatment apparatus 1 provided with the degassed fine bubble liquid production apparatus 10 according to the present embodiment described in detail below is not limited to the washing process in the production line as described above, but also includes used pipes and periodic Alternatively, it can be used for cleaning tanks and devices that need to be cleaned irregularly.

  In the following, as an example of the processing unit, there is a processing tank in which a processing liquid is held, and an example in which the processing object is provided so as to be filled with the processing liquid inside the processing tank will be described in detail. Will be described below.

  As illustrated in FIG. 1A, the ultrasonic processing apparatus 1 provided with the deaerated fine bubble liquid manufacturing apparatus 10 according to the present embodiment includes a processing tank 5 in which a processing liquid 3 is held, an ultrasonic application mechanism 7, ,have. Further, it is preferable that the ultrasonic processing apparatus 1 according to the present embodiment further includes a curved surface member 9 in addition to the above configuration.

  As illustrated in FIG. 1A, the deaerated fine bubble liquid manufacturing apparatus 10 provided in the ultrasonic processing apparatus 1 includes a processing liquid circulation path 11, a first pump 13, a second pump 15, have. Further, it is preferable that the deaerated fine bubble liquid producing apparatus 10 further has an adjusting mechanism 17 in addition to the above-described configuration.

  The processing liquid 3 in the processing tank 5 is drawn out to the circulation path 11 by the first pump 13 and the second pump 15 of the deaerated fine bubble liquid manufacturing apparatus 10. The withdrawn processing liquid 3 is degassed by the first pump 13 and the second pump 15, and fine bubbles are generated in the processing liquid 3 to become deaerated fine bubble liquid. The degassed fine bubble liquid is supplied into the processing tank 5 through the circulation path 11.

  Here, the fine bubble is a fine bubble having a bubble diameter of 100 μm or less. Among such fine bubbles, fine bubbles having a bubble diameter of μm may be referred to as microbubbles, and fine bubbles having a bubble diameter of nm may be referred to as nanobubbles. The fine bubble improves the propagation efficiency of the ultrasonic wave to the object to be processed, and improves the processability as a core of the ultrasonic cavitation.

  Further, as schematically shown in FIG. 1B, the number and arrangement of the ultrasonic wave applying mechanism 7, the curved surface member 9, and the deaerated fine bubble liquid producing apparatus 10 are not particularly limited, and the treatment tank is not limited. 5 can be arranged while appropriately adjusting the number according to the shape and size. Also, the size of each member in the drawings is appropriately emphasized for ease of explanation, and does not indicate the actual dimensions and the ratio between the members.

(Detailed configuration of ultrasonic processing apparatus 1)
Prior to a detailed description of the degassed fine bubble liquid manufacturing apparatus 10 according to the present embodiment, the ultrasonic processing apparatus 1 provided with the degassed fine bubble liquid manufacturing apparatus 10 will be described in detail.

<About processing tank 5>
The processing tank 5 as an example of the processing unit stores the processing liquid 3 used for performing a predetermined processing on the processing target and the processing target itself. As a result, the object to be processed accommodated in the processing tank 5 is in a state of being filled with the processing liquid 3. The type of the processing liquid 3 held in the processing tank 5 is not particularly limited, and a known processing liquid can be used according to the processing performed on the processing target.

  Here, the material used to form the processing tank 5 according to the present embodiment is not particularly limited, and may be various metal materials such as iron, steel, and stainless steel plate, and may be fiber-reinforced. Various plastic resins such as plastic (FRP) and polypropylene (PP) may be used, and various bricks such as acid-resistant brick may be used. That is, as the processing tank 5 constituting the ultrasonic processing apparatus 1 according to the present embodiment, a processing tank formed of the above-described material can be newly prepared, or an existing processing tank in various manufacturing lines can be prepared. It is also possible to use a processing tank.

  Also, the size of the processing tank 5 is not particularly limited, and even if the processing tank 5 is a large-sized processing tank having various shapes such as a liquid surface depth of about 1 to 2 m × a total length of about 3 to 25 m, the present embodiment is not limited to this embodiment. It can be used as the processing tank 5 of the ultrasonic processing apparatus 1 according to the above.

<About the ultrasonic wave application mechanism 7>
The ultrasonic wave application mechanism 7 applies ultrasonic waves of a predetermined frequency to the processing liquid 3 and the object to be processed which are accommodated in the processing tank 5. The ultrasonic wave application mechanism 7 is not particularly limited, and a known one such as an ultrasonic vibrator connected to an ultrasonic oscillator (not shown) can be used. 1A and 1B show the case where the ultrasonic wave applying mechanism 7 is provided on the wall surface of the processing tank 5, the installation position of the ultrasonic wave applying mechanism 7 on the processing tank 5 is not particularly limited. Instead, one or a plurality of ultrasonic transducers may be appropriately installed on the wall surface or the bottom surface of the processing tank 5. If the condition is such that the ultrasonic waves are uniformly transmitted to the entire processing tank 5, the balance of the oscillating load of each ultrasonic vibrator becomes uniform, so that the number of ultrasonic vibrators is plural. Even if it does, no interference occurs between the generated ultrasonic waves.

  The frequency of the ultrasonic wave output from the ultrasonic wave application mechanism 7 is preferably, for example, 20 kHz to 200 kHz. If the frequency of the ultrasonic wave is less than 20 kHz, the propagation of the ultrasonic wave may be hindered by large-sized bubbles generated from the surface of the object to be processed, and the effect of improving the processability by the ultrasonic wave may be reduced. Further, when the frequency of the ultrasonic wave exceeds 200 kHz, the linearity of the ultrasonic wave when processing the object to be processed becomes too strong, and the uniformity of the processing may be reduced. The frequency of the ultrasonic wave output from the ultrasonic wave application mechanism 7 is preferably 20 kHz to 150 kHz, and more preferably 25 kHz to 100 kHz.

  The frequency of the ultrasonic wave to be applied is preferably selected from an appropriate value within the above range according to the object to be processed. Depending on the type of the object to be processed, ultrasonic waves having two or more frequencies are applied. Is also good.

  Further, it is preferable that the ultrasonic wave application mechanism 7 has a frequency sweep function capable of applying an ultrasonic wave while sweeping the frequency within a predetermined range around a frequency of a selected ultrasonic wave. With such a frequency sweep function, the following two additional effects can be realized.

When an ultrasonic wave is applied to microbubbles including fine bubbles existing in a liquid, a force called Bjrknes force acts on the microbubbles, and the microbubbles have a resonant bubble radius depending on frequency. In accordance with R ₀ , the ultrasonic wave is drawn to the position of the antinode or node. Here, when the frequency of the ultrasonic wave is changed by the frequency sweeping function of the ultrasonic wave applying mechanism 7, the resonance bubble radius _R0 depending on the frequency is increased according to the change in the frequency. As a result, the bubble diameter at which cavitation occurs increases, and many microbubbles (for example, fine bubbles) can be used as cavitation nuclei. Thereby, the processing efficiency of the ultrasonic processing apparatus 1 according to the present embodiment is further improved by the frequency sweeping function of the ultrasonic application mechanism 7.

  On the other hand, as a general property of ultrasonic waves, there is known a phenomenon that “when the wavelength of the ultrasonic wave becomes １ ／ of the wavelength corresponding to the thickness of the irradiated object, the ultrasonic wave transmits through the irradiated object”. I have. Therefore, by applying ultrasonic waves while sweeping the frequency within an appropriate range, for example, when the object to be processed has a hollow portion such as a tubular body, the ultrasound transmitted to the tubular body is increased. As a result, the processing efficiency of the ultrasonic processing apparatus 1 according to the present embodiment is further improved.

  Here, when considering the transmission of the ultrasonic wave on the surface of the irradiation object, not only when the ultrasonic wave is perpendicularly incident on the irradiation object, but also because the ultrasonic wave propagates while repeating multiple reflections, it is difficult to form a constant sound field. There is a tendency. Among them, in order to create a condition for transmitting through the wall surface of the irradiation object, no matter where the position of the processing object exists, “the wavelength of the ultrasonic wave is １ ／ of the wavelength corresponding to the thickness of the processing object. It is preferable to realize a frequency that can satisfy the condition of For such a range of frequencies, the present inventors have studied, by applying ultrasonic waves while sweeping the frequency in the range of ± 0.1 kHz to ± 10 kHz around a certain selected ultrasonic frequency, It has been clarified that the transmission of ultrasonic waves as described above is feasible. For these reasons, the ultrasonic wave application mechanism 7 has a frequency sweep function capable of applying ultrasonic waves while sweeping the frequency in the range of ± 0.1 kHz to ± 10 kHz around a selected ultrasonic frequency. It is preferable to have

<About the curved member 9>
The curved member 9 is a member having a curved surface that is convex toward the vibration surface of the ultrasonic wave application mechanism 7 and is a member that reflects the ultrasonic waves that have reached the curved member 9 in multiple directions. By providing such a curved surface member 9 on at least one of the wall surface and the bottom surface in the processing tank 5, the ultrasonic waves generated from the vibration surface of the ultrasonic wave application mechanism 7 can be transmitted to the entire inside of the processing tank 5. It becomes possible.

  More specifically, the curved member 9 according to the present embodiment has at least a convex curved portion having a spherical or aspherical surface shape, and the convex curved portion has an ultrasonic wave more than a portion other than the convex curved portion. It has a convex curved surface projecting toward the vibration surface side of the application mechanism 7. In addition, the curved surface member 9 according to the present embodiment may have a non-convex curved portion that is not a convex curved portion, or may be configured only with a convex curved surface. Further, the curved surface member 9 according to the present embodiment may be a solid columnar body or a hollow cylindrical body. When the curved member 9 is hollow, various gases such as air may be present in the gap of the curved member 50 mounted on the processing tank 5, or may be held in the processing tank 5. Various liquids such as the processing liquid 3 may be present.

  When the curved surface member 9 has the above-mentioned convex curved surface, the ultrasonic waves are reflected in multiple directions, and uniform ultrasonic wave propagation without bias is realized, and interference between the ultrasonic waves can be suppressed. Here, when the curved surface member 9 includes a concave portion, the ultrasonic wave is reflected by the concave portion to be focused, so that the ultrasonic wave cannot be effectively reflected to the entire processing tank 5. Even when the projections include the projections, if the projections are not curved surfaces but flat surfaces, the ultrasonic waves can be reflected only in one direction, and the ultrasonic waves can be effectively applied to the entire processing tank 5. It cannot be reflected.

The curved member 9 having the above-described shape is preferably formed using a material that reflects ultrasonic waves. As such a material, for example, a material having an acoustic impedance (intrinsic acoustic impedance) of 1 × 10 ⁷ [kg · m ⁻² · sec ⁻¹ ] or more and 2 × 10 ⁸ [kg · m ⁻² · sec ⁻¹ ] or less Can be mentioned. By using a material having an acoustic impedance of 1 × 10 ⁷ [kg · m ⁻² · sec ⁻¹ ] or more and 2 × 10 ⁸ [kg · m ⁻² · sec ⁻¹ ] or less, ultrasonic waves are efficiently reflected. It becomes possible.

As a material having an acoustic impedance of 1 × 10 ⁷ [kg · m ⁻² · sec ⁻¹ ] or more and 2 × 10 ⁸ [kg · m ⁻² · sec ⁻¹ ] or less, for example, various metals or metal oxides And various ceramics including non-oxide ceramics. Specific examples of such a material include, for example, steel (intrinsic acoustic impedance [kg · m ⁻² · sec ⁻¹ ]: 4.70 × 10 ⁷ ; ), Iron (3.97 × 10 ⁷ ), stainless steel (SUS, 3.97 × 10 ⁷ ), titanium (2.73 × 10 ⁷ ), zinc (3.00 × 10 ⁷ ), nickel ( 5.35 × 10 ⁷ ), aluminum (1.38 × 10 ⁷ ), tungsten (1.03 × 10 ⁸ ), glass (1.32 × 10 ⁷ ), quartz glass (1.27 × 10 ⁷ ), glass Lining (1.67 × 10 ⁷ ), alumina (aluminum oxide, 3.84 × 10 ⁷ ), zirconia (zirconium oxide, 3.91 × 10 ⁷ ), silicon nitride (SiN, 3.15 × 10 ⁷ ), carbonization Silicon (SiC, .92 × ¹⁰ 7), tungsten carbide (WC, there is 9.18 × 10 ⁷⁾ or the like. In the curved member 9 according to the present embodiment, a material used for forming the curved member 9 may be appropriately selected according to the liquid property of the processing liquid 3 held in the processing tank 5 and the strength required for the curved member 9. It is preferable to use various metals or metal oxides having the above-described acoustic impedance.

<About the reflector>
It is preferable that a reflecting plate for reflecting ultrasonic waves is provided on the wall surface and the bottom surface of the processing bath 5 on the processing liquid side. By providing such a reflection plate, the ultrasonic wave that has reached the wall surface or the bottom surface of the processing tank 5 is reflected by the reflection plate and propagates toward the processing liquid 3 again. This makes it possible to efficiently use the ultrasonic waves applied to the processing liquid 3.

  In particular, by providing a reflecting plate for reflecting ultrasonic waves between the curved surface member 9 and the wall surface or the bottom surface of the processing tank 5 holding the curved surface member 9, more efficient use of ultrasonic waves. Becomes possible.

  As above, the overall configuration of the ultrasonic processing apparatus 1 according to the present embodiment has been described in detail with reference to FIGS. 1A and 1B.

  In the above description, the processing object filled with the processing liquid 3 is provided inside the processing tank 5 provided as a processing unit, and then the processing liquid 3 held in the processing tank 5 is interposed. Although the case where the ultrasonic wave is applied indirectly to the object to be processed has been described as an example, the ultrasonic wave application mechanism 7 applies the ultrasonic wave directly to the object to be processed filled with the processing liquid in the processing unit. May be.

  For example, a hollow member in which the inside is filled with a liquid, such as a pipe provided inside a heat exchanger or a connection pipe connecting a plurality of facilities using a liquid, is an object to be processed. It may be. In such a case, after generating fine bubbles with respect to the liquid held inside the hollow member, ultrasonic waves are applied to the hollow member itself.

(Detailed configuration of the deaerated fine bubble liquid production apparatus 10)
Subsequently, the degassed fine bubble liquid manufacturing apparatus 10 provided in the ultrasonic processing apparatus 1 as described above will be described in detail with reference to FIGS. 1A to 2.
FIG. 2 is an explanatory view schematically showing a modified example of the degassed fine bubble liquid producing apparatus according to the present embodiment and an example of the configuration of an ultrasonic processing apparatus provided with the degassed fine bubble liquid producing apparatus. is there.

  The degassed fine bubble liquid producing apparatus 10 according to the present embodiment has at least the circulation path 11, the first pump 13, and the second pump 15, as mentioned earlier. Further, it is preferable that the degassed fine bubble liquid producing apparatus 10 according to the present embodiment further includes an adjusting mechanism 17 in addition to the above configuration.

  The circulation path 11 is a path for circulating the processing liquid 3 held in the processing tank 5. The circulation path 11 may use a circulation path provided in the processing tank 5 in advance, or may be a new one installed in the processing tank 5. The processing liquid 3 withdrawn from the processing tank 5 by the operation of the first pump 13 and the second pump 15 described below is degassed by the cooperation of the first pump 13 and the second pump 15, and Fine bubbles are generated in the processing liquid 3 and become deaerated fine bubble liquid. The deaerated fine bubble liquid is discharged into the processing tank 5 through the circulation path 11.

  The first pump 13 and the second pump 15 are provided in the middle of the circulation path 11 in series with the circulation path 11. In the present embodiment, the first pump 13 is a pump for extracting the processing liquid 3 from the processing tank 5. In addition, the second pump 15 is provided on the circulation path 11 on the side where the processing liquid is withdrawn from the first pump 13 (upstream of the flow of the processing liquid 3). It operates to transport 3.

  In the degassed fine bubble liquid production apparatus 10 according to the present embodiment, when producing the degassed fine bubble liquid, both the first pump 13 and the second pump 15 are operated, and the first pump 13 The inside of the circulation path 11 located between the second pump 15 and the second pump 15 is depressurized. Hereinafter, the circulation path 11 located between the two pumps 13 and 15 will be referred to as an “inter-pump region 11A”. In the degassed fine bubble liquid manufacturing apparatus 10 according to the present embodiment, the processing liquid 3 existing in the inter-pump region 11A is degassed by reducing the pressure inside the inter-pump region 11A. Fine bubbles are generated to make deaerated fine bubble liquid.

  Here, the average bubble diameter of the fine bubbles in the produced degassed fine bubble liquid is preferably 0.01 μm to 100 μm. Here, the average bubble diameter is a diameter at which the number of samples becomes maximum in a number distribution related to the diameter of the fine bubble. When the average bubble diameter is less than 0.01 μm, the two pumps 13 and 15 used are large, and it may be difficult to generate fine bubbles by adjusting the bubble diameter. When the average bubble diameter exceeds 100 μm, the life of the fine bubbles in the cleaning liquid is shortened due to an increase in the floating speed of the fine bubbles, and a realistic cleaning process may not be performed in the processing tank 5. . If the bubble diameter is too large, the propagation of the ultrasonic waves is hindered by the fine bubbles, and the effect of the ultrasonic waves to improve the detergency may be reduced.

The concentration of fine bubbles in the degassed fine bubble liquid to be produced (density) is preferably 10 ³ / ml to 10 ¹⁰ cells / mL. When the concentration of the fine bubbles is less than 10 ³ / mL, the effect of improving the ultrasonic wave propagation by the fine bubbles may not be sufficiently obtained, and the number of nuclei of the ultrasonic cavitation required for the treatment may decrease. It is not preferable. In addition, when the concentration of fine bubbles is more than 10 ¹⁰ / mL, the two pumps 13 and 15 to be used become large, and supply of fine bubbles may not be realistic, which is not preferable.

  Further, in the degassed fine bubble liquid manufacturing apparatus 10 according to the present embodiment, in the degassed fine bubble liquid to be manufactured, fine bubbles having a bubble diameter equal to or smaller than a frequency resonance diameter that is a diameter resonating with the frequency of the ultrasonic wave are produced. It is preferable to generate fine bubbles such that the ratio of the number is 70% or more of the total number of fine bubbles existing in the degassed fine bubble liquid. Hereinafter, the reason will be described.

  The natural frequencies of various bubbles including fine bubbles are also referred to as Minnaert resonance frequencies and are given by the following equation (11).

Here, in the above equation 11,
f ₀ : natural frequency of bubble (Minnaert resonance frequency)
R ₀ : average radius of bubble p _∞ : average pressure of surrounding liquid γ: adiabatic ratio (γ of air = 1.4)
ρ: liquid density.

Now, assuming that air is present inside the bubble of interest, the liquid surrounding the bubble is water, and the pressure is atmospheric pressure, the product f ₀ R of the natural frequency of the bubble and the average radius of the bubble. The value of ₀ is about 3 kHz · mm from the above equation (11). Thus, if the frequency of the applied ultrasonic wave is 20 kHz, the radius R ₀ of the bubble that resonates with the ultrasonic wave is about 150 μm. The diameter 2R ₀ is about 300 μm. Similarly, if the frequency of the applied ultrasonic wave is 100 kHz, the radius R ₀ of the bubble that resonates with the ultrasonic wave is about 30 μm. The diameter 2R ₀ is about 60 μm.

At this time, bubbles having a radius larger than the resonance radius _R0 become an inhibitory factor. This is because when bubbles including fine bubbles resonate, the bubbles repeat expansion and contraction in a short time and eventually collapse, but when the first sound wave passes through the bubbles, the size of the bubbles becomes frequency resonance. larger than the diameter 2R _0, ultrasound is because diffuses bubbles surface. Conversely, the size of the bubbles at the time the first acoustic wave passes through the bubble is smaller than the frequency resonance diameter 2R _0, ultrasound can pass through the bubble without diffusing bubbles surface.

From this point of view, and in degassed fine bubble liquid, the ratio of the number of fine bubbles having a bubble size of less frequency resonant diameter 2R _0, 70% or more of fine bubbles whole number present in the degassed fine bubble liquid Is preferred. By the ratio of the number of fine bubbles having a bubble size of less frequency resonant diameter 2R ₀ and 70%, it is possible to further improve the propagation efficiency of the ultrasonic wave. Further, by transmitting the first sound wave to the wall surface / bottom surface of the processing tank 5, the diffusion and reflection of the ultrasonic wave to the entire processing tank 5 are repeated, so that a uniform ultrasonic processing tank can be realized. . Further, it is possible to bubble was less frequency resonant diameter 2R ₀ even by repeating expansion and contraction and exceeds a predetermined ultrasonic irradiation time and crushing, contributing to the process using the cavitation.

The ratio of the number of fine bubbles having a bubble size of less frequency resonant diameter 2R _0, considering that no small bubbles to expand immediately after the fine bubble is preferably 98% or less. Ratio of the number of fine bubbles having a bubble size of less frequency resonant diameter 2R ₀ is more preferably 98% or less than 80%.

  Here, the average bubble diameter and concentration (density) of the fine bubbles can be measured by a known device such as a liquid particle counter or a bubble diameter distribution measuring device. A method for controlling the average bubble diameter and concentration (density) of the fine bubbles in the degassed fine bubble liquid will be described later.

  In the ultrasonic processing apparatus 1 according to the present embodiment, in order to achieve both more uniform ultrasonic wave propagation and high detergency, the amount of dissolved gas in the manufactured degassed fine bubble liquid (more specifically, , Dissolved oxygen amount) to an appropriate value. The appropriate amount of dissolved gas in such a degassed fine bubble liquid is preferably 1% to 50% of the dissolved saturation in the degassed fine bubble liquid. When the dissolved gas amount is less than 1% of the dissolved saturation amount, it is difficult to generate air bubbles as fine bubbles, and cavitation does not occur due to ultrasonic waves, and the processability improving ability by ultrasonic waves (surface This is not preferable because the possibility of not being able to exert its ability to improve the processability is increased. On the other hand, when the dissolved gas amount exceeds 50% of the dissolved saturation amount, the propagation of the ultrasonic wave is hindered by the dissolved gas, and there is a high possibility that the uniform ultrasonic wave propagation to the entire processing tank 5 is hindered. Is not preferred. The dissolved gas amount (dissolved oxygen amount) in the degassed fine bubble liquid is preferably 5% to 40% or less of the dissolved saturation amount in the degassed fine bubble liquid. By using the ultrasonic treatment apparatus 1 including the deaerated fine bubble liquid production apparatus 10 according to the present embodiment, the deaerated fine bubble having a dissolved gas amount corresponding to 1% to 50% of the dissolved saturation amount as described above. A liquid can be produced and the degassed fine bubble liquid can be circulated more stably.

  Here, if the temperature of the degassed fine bubble liquid changes, the dissolved saturation amount of the degassed fine bubble liquid changes. Further, a difference in molecular momentum (for example, water molecule momentum) of a liquid constituting the degassed fine bubble liquid due to a temperature change of the degassed fine bubble liquid affects the propagating property. Specifically, when the temperature is low, the molecular momentum of the liquid constituting the degassed fine bubble liquid is small, the ultrasonic wave is easily propagated, and the dissolved saturation amount (dissolved oxygen amount) in the degassed fine bubble liquid is also increased. . Therefore, it is preferable to appropriately control the temperature of the degassed fine bubble liquid so that a desired dissolved gas amount (dissolved oxygen amount) within the above range can be realized. The temperature of the degassed fine bubble liquid depends on the specific processing performed using the degassed fine bubble liquid, but is preferably, for example, about 20 ° C to 85 ° C.

  Specifically, the dissolved gas amount in the degassed fine bubble liquid is, for example, preferably from 0.1 ppm to 11.6 ppm, more preferably from 1.0 ppm to 11.0 ppm. Therefore, the degassed fine bubble liquid manufacturing apparatus 10 according to the present embodiment is configured so that the amount of dissolved gas in the manufactured degassed fine bubble liquid becomes a value in the above-described range. The temperature of 3 and the amount of dissolved gas in the processing liquid 3 are controlled. The method of controlling the dissolved gas amount of the degassed fine bubble liquid will be described below again.

  Here, the amount of dissolved gas in the degassed fine bubble liquid can be measured by a known device such as a diaphragm electrode method and an optical dissolved oxygen meter.

  The dissolved gases in the aqueous solution are mainly oxygen, nitrogen, carbon dioxide, helium, and argon, and although they are affected by the temperature and components of the aqueous solution, the majority are oxygen and nitrogen. In addition, the dissolved gas that can affect various types of ultrasonic treatment as noted in the present embodiment is mainly oxygen.

  In order to surely create a decompressed state inside the inter-pump region 11A and produce the above-described degassed fine bubble liquid, the degassing fine bubble liquid manufacturing apparatus 10 according to the present embodiment uses the entirety of the first pump 13. The head is set to 15 m or more, and the total head of the second pump 15 is set to (total head of the first pump 13 −15) m or more and equal to or less than the total head of the first pump 13. However, the total head of the second pump 15 has a value exceeding 0 m. When the total head of the first pump 13 is less than 15 m, or when the total head of the second pump 15 is less than (the total head of the first pump 13−15) m, the inside of the inter-pump region 11 </ b> A is formed. However, it is not possible to create a reduced pressure for producing the degassed fine bubble liquid as described above. Further, if the total head of the second pump 15 exceeds the total head of the first pump 13, a backflow or stagnation of the processing liquid 3 to be circulated occurs, which is not preferable.

  Although the upper limit of the total head of the first pump 13 is not particularly specified, when the total head of the first pump 13 exceeds 40 m, the second pump must also have a high total head. Even if both heads are unnecessarily high, the deaeration level and the amount of fine bubbles generated hardly increase in many cases. Therefore, the total head of the first pump 13 is preferably 40 m or less. The total head of the first pump 13 is more preferably 20 m or more and 35 m or less. The total head of the second pump 15 is more preferably (the total head of the first pump 13 −15) m or more and less than the total head of the first pump 13, and still more preferably (the total head of the first pump 13 −). 10) m or more (the total head of the first pump 13-5) m or less.

  In other words, in the deaerated fine bubble liquid manufacturing apparatus 10 according to the present embodiment, when the total head of the first pump 13 is L1 [m] and the total head of the second pump 15 is L2 [m], It is preferable that the difference (L1-L2) between the total head of the first pump 13 and the total head of the second pump 15 is 5 m or more and 10 m or less. When the difference (L1-L2) in the total head is within the above range, a more preferable degassed fine bubble liquid can be produced more reliably.

  In the deaerated fine bubble liquid manufacturing apparatus 10 according to the present embodiment, in order to more reliably manufacture the above-described deaerated fine bubble liquid, the processing liquid 3 in the circulation path 11 (particularly, in the inter-pump region 11A). Is controlled so as to be in the range of 0.05 to 5.00 m / sec, and the pressure inside the inter-pump region 11A is in the range of -0.25 to -0.08 MPa. Is preferably controlled. Such flow velocity and pressure of the processing liquid 3 can be realized by controlling the operating state of the first pump 13 and the second pump 15 (that is, the rotation speed of the motor of each pump). In order to realize such individual control of the number of rotations of the motor in each pump, the deaerated fine bubble liquid manufacturing apparatus 10 according to the present embodiment includes the number of rotations of the motor of the first pump 13 and the number of rotations of the second pump 15. It is preferable to further include an adjustment mechanism 17 that adjusts the flow rate and the pressure of the processing liquid 3 by inverter-controlling the rotation speed of the motor independently of each other. By further providing such an adjusting mechanism 17, finer control of the number of rotations of the motors of the first pump 13 and the second pump 15 becomes possible, and the production conditions of the deaerated fine bubble liquid are more finely adjusted. It becomes possible. The adjusting mechanism 17 can be realized by mounting the above-described functions in, for example, a process computer that controls the operation state of the ultrasonic processing apparatus 1 according to the present embodiment. is there.

  Here, when the maximum discharge amount of the first pump 13 is Q1 [L / min] and the maximum discharge amount of the second pump 15 is Q2 [L / min], the maximum discharge amount of the first pump 13 It is preferable that the ratio (Q2 / Q1) to the maximum discharge amount of the two pumps 15 be 0.5 or more and 1.0 or less. The maximum discharge amount of each of the pumps 13 and 15 can be more easily realized by, for example, using the adjustment mechanism 17 as described above and controlling the number of rotations of the motor of each pump with an inverter. When the ratio of the maximum discharge amount (Q2 / Q1) is within the above range, it is possible to more reliably produce a degassed fine bubble liquid in a more preferable state. The maximum discharge amount ratio (Q2 / Q1) is more preferably 0.7 or more and 1.0 or less.

  Further, in the degassed fine bubble liquid manufacturing apparatus 10 according to the present embodiment, the volume of the circulation path 11 (that is, the inter-pump region 11A) located between the first pump 13 and the second pump 15 is determined by the processing unit ( For example, the total volume of the circulation system including the processing tank 5) as an example and the entire circulation path 11 is preferably set at 1 / 10,000 or more. When the volume of the inter-pump region 11A is less than 1 / 10,000 with respect to the total volume of the circulation system, the volume of the inter-pump region 11A becomes too small, and as a result, the degassing rate of the processing liquid becomes low. There is a possibility that such degassed fine bubble liquid cannot be produced sufficiently. On the other hand, the upper limit of the volume of the inter-pump region 11A with respect to the total volume of the circulating system is not particularly specified, but the volume of the inter-pump region 11A exceeds 1/500 of the total volume of the circulating system. Since the volume of the inter-pump region 11A becomes relatively large with respect to the volume of the entire circulating system, and the amount of the processing liquid to be degassed increases, the required pump becomes large, which is economically disadvantageous. It is preferred to be 1/500 or less.

  In addition, as shown in FIG. 1B, when a plurality of deaerated fine bubble liquid manufacturing apparatuses 10 are installed for one processing tank 5, for example, the processing unit (for example, the processing tank 5 as an example) and It is preferable that the volume of the inter-pump region 11A in each of the degassed fine bubble liquid producing apparatuses 10 is equal to or greater than 1 / 10,000 with respect to the total volume of the entire circulation system including the plurality of circulation paths 11.

  In the deaerated fine bubble liquid manufacturing apparatus 10 according to the present embodiment, the average bubble diameter and concentration (density) of the fine bubbles in the deaerated fine bubble liquid appropriately control control conditions such as the pressure in the inter-pump region 11A. Thus, it is possible to control the value to be within a desired range. At this time, while measuring the average bubble diameter and concentration (density) of the fine bubbles on the downstream side of the first pump 13 (downstream of the flow of the processing liquid 3 in the circulation path 11) by the known device as described above, Each of the above control conditions may be adjusted until the average bubble diameter and the concentration (density) of the fine bubbles fall within desired ranges.

  Also, regarding the amount of dissolved gas in the degassed fine bubble liquid, control conditions such as the pressure in the inter-pump region 11A and one operation time (time during which the pump is ON) in each pump are appropriately controlled. Thus, it is possible to control the value to be within a desired range. At this time, while controlling the dissolved gas amount with the above-described known device on the downstream side of the first pump 13 (downstream of the flow of the processing liquid 3 in the circulation path 11), the control conditions as described above are adjusted. It may be adjusted until the dissolved gas amount becomes a value within a desired range.

  In the deaerated fine bubble liquid manufacturing apparatus 10 according to the present embodiment, when the deaerated fine bubble liquid is manufactured, both the first pump 13 and the second pump 15 are operated as described above. However, when the production of the degassed fine bubble liquid is continued, air bubbles accumulate in the casing of each pump and in the inter-pump region 11A. If the bubbles stay, the production efficiency of the degassed fine bubble liquid is reduced, and damage due to the bubbles is accumulated in each pump. Therefore, the bubbles remaining in the casing of each pump and in the area 11A between the pumps are removed. Is preferred.

  Here, the degassed fine bubble liquid producing apparatus 10 according to the present embodiment has two pumps 13 and 15 that can operate independently of each other. Therefore, by setting one of the pumps to the operating state and the other pump to the stop state, the depressurized state of the inter-pump region 11A is released, and the pump stays in the casing of each pump and the inter-pump region 11A. It is possible to easily remove the generated air bubbles. At this time, the circulation path 11 is located downstream of the first pump 13 (downstream of the flow of the processing liquid 3), and is located upstream of the second pump 15 (upstream of the flow of the processing liquid 3). An air release valve (not shown) is provided at any position of the circulation path 11, or an exhaust path provided with an air release valve in the middle of the inter-pump region 11 </ b> A as schematically shown in FIG. 2. By providing the air bubbles, it is possible to more easily remove the remaining air bubbles.

  The deaerated fine bubble liquid manufacturing apparatus 10 according to the present embodiment has been described above in detail with reference to FIGS. 1A to 2.

(About degassing fine bubble liquid production method)
Next, a method for producing a degassed fine bubble liquid using the degassed fine bubble liquid production apparatus 10 described above will be briefly described with reference to FIG. FIG. 3 is an explanatory diagram for describing the method for producing a degassed fine bubble liquid according to the present embodiment.

  In the method for producing a degassed fine bubble liquid according to the present embodiment, both the first pump 13 and the second pump 15 are operated while using the degassing fine bubble liquid production apparatus 10 as described above, and the first By performing the deaeration and fine bubble generation processes for reducing the pressure inside the circulation path 11 (that is, the inter-pump region 11A) located between the pump 13 and the second pump 15, the deaerated fine bubble liquid is removed. To manufacture.

  Here, in the above-described degassing and fine bubble generation process, the flow rate of the processing liquid 3 in the circulation path 11 (particularly, in the inter-pump region 11A) is adjusted within a range of 0.05 to 5.00 m / sec. In addition, it is preferable to adjust the pressure inside the inter-pump region 11A within a range of -0.25 to -0.08 MPa. By setting the flow rate of the processing liquid 3 in the circulation path 11 and the pressure inside the inter-pump region 11A within the above ranges, the degassed fine bubble liquid can be produced more reliably.

  Also, as mentioned earlier, when both the first pump 13 and the second pump 15 continue to operate, air bubbles stay in the casings of the first pump 13 and the second pump 15 and in the inter-pump region 11A. I will do it. Therefore, in the method for producing a degassed fine bubble liquid according to the present embodiment, the degassing and fine bubble liquid production described above is performed in order to remove air bubbles remaining in the casings of the first pump 13 and the second pump 15 and the inter-pump region 11A. In addition to the fine bubble generation process, one of the first pump 13 and the second pump 15 is stopped, so that the casings of the first pump 13 and the second pump 15 and the first pump 13 and the second pump 15 are stopped. It is preferable to perform a gas discharge process of discharging gas remaining inside the circulation path 11 (that is, the inter-pump region 11A) located between the first and second pumps.

Specifically, as schematically shown in FIG. 3, it is preferable to alternately perform the degassing and fine bubble generation process and the gas discharge process. More specifically, the time _{t A} per one degassing and fine bubble generation process, and in the range of 60 to 3,600 seconds, and a time _{t B} per one gas discharge process, 1 to 60 seconds Is preferably within the range. By performing such a gas discharging process, the degassed fine bubble liquid can be more reliably produced without causing damage to the degassed fine bubble liquid producing apparatus 10. Time t _A per one degassing and fine bubble generation process, more preferably in the range of 120 to 360 seconds, the time t _B per one gas discharge process, more preferably 3 to 20 seconds Is within the range.

  As above, the method for producing a degassed fine bubble liquid according to the present embodiment has been briefly described with reference to FIG.

(About ultrasonic treatment method)
Subsequently, an ultrasonic processing method using the ultrasonic processing apparatus provided with the degassed fine bubble liquid manufacturing apparatus as described above will be briefly described.

  The ultrasonic processing method according to the present embodiment holds a processing liquid 3 for performing a predetermined processing on an object to be processed, a processing unit in which the object is filled with the processing liquid 3, and a processing unit provided in the processing unit. The ultrasonic processing apparatus 1 includes at least the ultrasonic wave applying mechanism 7 for applying ultrasonic waves to the object to be processed and the above-described degassed fine bubble liquid manufacturing apparatus 10 provided for the processing unit. Sonication method to be performed.

  In such an ultrasonic treatment method, both the first pump 13 and the second pump 15 are operated, and the circulation path 11 (that is, the inter-pump region 11A) located between the first pump 13 and the second pump 15 is operated. A degassing fine bubble liquid is produced by a degassing and fine bubble generation process in which the inside is depressurized, and the produced degassed fine bubble liquid is supplied to the processing unit while the ultrasonic wave applying mechanism 7 is applied to the object to be processed. To apply ultrasonic waves. This makes it possible to perform a predetermined process using ultrasonic waves together on the surface of the object to be processed (the portion in contact with the processing liquid).

  In the ultrasonic treatment method according to the present embodiment, when producing the degassed fine bubble liquid, in addition to the degassing and fine bubble generation steps described above, the gas discharging step described above is performed. Is preferred.

  As above, the ultrasonic processing method according to the present embodiment has been briefly described.

  Hereinafter, the present invention will be specifically described with reference to Examples and Comparative Examples. The embodiments described below are merely examples of the present invention, and the present invention is not limited to the following examples.

In the following, a cleaning tank having a length of 20 m, a width of 1.25 m and a depth of 1.2 m as an example of a processing unit was equipped with four deaerated fine bubble liquid manufacturing apparatuses according to the present invention, and verified. Was done. The total volume of the circulation system including the entire circulation path of the cleaning tank and the degassed fine bubble liquid manufacturing apparatus was 25 m ³ (25000 L). In each degassed fine bubble liquid production apparatus, two pumps (both MEP-0505-2P manufactured by Seiko Kakoki Co., Ltd.) installed in the circulation path were used, as shown in Table 1-1 and Table 1-2 below. The total head [m] and the maximum discharge rate [L / min] were adjusted. The volume [L] of the region between the pumps was adjusted by changing the interval between the two pumps.

  As a treatment liquid (washing liquid), industrial water obtained by filtering water collected from a river was used. When the dissolved oxygen concentration of the treatment liquid was measured using a dissolved oxygen meter (LAQUA OM-51), it was 7.8 ppm at 35 ° C.

  In this experimental example, the object to be cleaned is a vertical heat exchanger in which SS pipes having an inner diameter of 45 mm, a length of 3.0 m, and a thickness of 9 mm are continuously connected. After the object to be cleaned was immersed near the center in the cleaning tank, the water in the cleaning tank was fed into the pipe of the vertical heat exchanger. The cleaning tank is supplied with the degassed fine bubble liquid produced by the degassing fine bubble liquid production apparatus as needed. The production time of the degassed fine bubble liquid was 90 minutes.

Ultrasonic waves (frequency: 28 kHz, output: 1200 W) were applied from ten ultrasonic oscillators based on the start of the production of the degassed fine bubble liquid. The ultrasonic transducers are evenly arranged in the cleaning tank. The production time of the deaerated fine bubble liquid was 90 minutes, and the deaeration and fine bubble generation process and the gas discharge process were alternately performed. Time t _A per one degassing and fine bubble generation _process, the time t _B per one gas discharge process are as shown in Tables 1-1 and Table 1-2.

  Here, each of the flow velocity [m / min] and the pressure [MPa] in the region between the pumps was measured using a flow meter and a pressure gauge installed in this section. The average bubble diameter of the fine bubbles in the processing liquid at the position where the deaerated fine bubble liquid is supplied to the cleaning tank is measured using a precision particle size distribution analyzer Multisizer 4 manufactured by Beckman Coulter, and The dissolved oxygen concentration was measured using a dissolved oxygen meter (LAQUA OM-51). In Tables 1-1 and 1-2 below, the concentration of fine bubbles indicates a common logarithm of the obtained concentration [number / mL].

  Regarding the ultrasonic cleaning performance, the cleanliness in the pipe was measured and evaluated as the cleaning performance. More specifically, 1 L of the treatment liquid one minute after the start of washing was collected from the washing tank, and the turbidity of the collected treatment liquid was measured. The turbidity meter used was TC-3000 manufactured by Optex Corporation. From the obtained turbidity, the cleaning performance was evaluated according to the following evaluation criteria.

Cleanliness (turbidity) 3000 or less 1500 or more: A
Less than 1500 and 800 or more: B
Less than 800 and more than 500: C
Less than 500 and more than 300: D
Less than 300, 1 or more: E

  That is, the score “A” means that the sediment in the pipe could be collected, the turbidity increased, and the cleaning performance was very good, and the score “B” showed that the cleaning performance was good. The rating "C" means that the cleaning performance was slightly better, the rating "D" means that the cleaning performance was at an acceptable level, and the rating "E" was Means that the cleaning performance was poor.

  The obtained results are shown in Tables 1-1 and 1-2 below.

  As is clear from the above Tables 1-1 and 1-2, when the degassed fine bubble liquid producing apparatus corresponding to the embodiment of the present invention is used, it is possible to produce a degassed fine bubble liquid suitable for cleaning. It was possible, and it was found that the ultrasonic cleaning performance using such a degassed fine bubble liquid showed good results. On the other hand, when using the degassed fine bubble liquid production apparatus corresponding to the comparative example of the present invention, it is not possible to produce a degassed fine bubble liquid suitable for cleaning, and ultrasonic waves using such a degassed fine bubble liquid The cleaning performance was not good.

  As described above, the preferred embodiments of the present invention have been described in detail with reference to the accompanying drawings, but the present invention is not limited to such examples. It is obvious that those skilled in the art to which the present invention pertains can conceive various changes or modifications within the scope of the technical idea described in the claims. It is understood that these also belong to the technical scope of the present invention.

DESCRIPTION OF SYMBOLS 1 Ultrasonic processing apparatus 3 Processing liquid 5 Processing tank 7 Ultrasonic application mechanism 9 Curved surface member 10 Deaerated fine bubble liquid manufacturing apparatus 11 Circulation path 11A Area between pumps 13 First pump 15 Second pump 17 Adjusting mechanism

Claims (17)

A degassing fine for producing a degassing fine bubble liquid, which is a degassed and processing liquid containing fine bubbles, which is supplied to a processing section in which a processing liquid for performing a predetermined processing on an object to be processed is held. A bubble liquid producing apparatus,
A circulation path for circulating the processing liquid withdrawn from the processing unit to the processing unit;
A first pump, which is provided on the circulation path and withdraws the processing liquid from the processing unit, and has a total head of 15 m or more;
On the circulating path, the pump is provided on the drawing side of the processing liquid with respect to the first pump, and operates so as to convey the processing liquid in a direction opposite to the first pump. A second pump having a total head of −15) m or more and a total head of the first pump or less,
With
By activating both the first pump and the second pump to depressurize the inside of the circulation path located between the first pump and the second pump, the processing liquid is degassed. A deaerated fine bubble liquid producing apparatus, wherein the fine bubbles are generated in the treatment liquid to produce the deaerated fine bubble liquid, and the obtained deaerated fine bubble liquid is supplied to the processing section.   By controlling the rotation speed of the motor of the first pump and the rotation speed of the motor of the second pump independently of each other, the flow rate of the processing liquid and the flow rate between the first pump and the second pump are controlled. The deaerated fine bubble liquid producing apparatus according to claim 1, further comprising an adjusting mechanism that adjusts a pressure inside the circulation path located at a position corresponding to the deaerated fine bubble liquid.   The adjusting mechanism controls the motor of the first pump so that the flow rate of the processing liquid in the circulation path during the production of the degassed fine bubble liquid is in the range of 0.05 to 5.00 m / sec. The deaerated fine bubble liquid producing apparatus according to claim 2, wherein the number of revolutions and the number of revolutions of a motor of the second pump are controlled.   When the maximum discharge amount of the first pump is Q1 [L / min] and the maximum discharge amount of the second pump is Q2 [L / min], the maximum discharge amount of the first pump and the second pump The deaerated fine bubble liquid manufacturing apparatus according to claim 2 or 3, wherein a ratio (Q2 / Q1) to a maximum discharge amount of the liquid is set to 0.5 or more and 1.0 or less.   The volume of the circulation path located between the first pump and the second pump is set at 1 / 10,000 or more of the total volume of a circulation system including the processing unit and the entire circulation path. 5. The degassed fine bubble liquid producing apparatus according to any one of 4.   When the total head of the first pump is L1 [m] and the total head of the second pump is L2 [m], the difference between the total head of the first pump and the total head of the second pump ( The degassed fine bubble liquid production apparatus according to any one of claims 1 to 5, wherein L1-L2) is 5 m or more and 10 m or less.   7. The fine bubble according to claim 1, wherein the fine bubbles are generated such that a dissolved gas amount is 50% or less of a saturated dissolved gas amount in the processing liquid discharged to the processing unit. 8. Degassing fine bubble liquid production equipment. In the processing solution discharged to the processing unit, the fine bubbles having an average bubble diameter of 0.01 μm to 100 μm exist in a range of a total bubble amount of 10 ³ bubbles / mL to ¹⁰ 10 bubbles / mL. The deaerated fine bubble liquid producing apparatus according to any one of claims 1 to 7, wherein the fine bubbles are generated. A method for producing a degassed fine bubble liquid using the degassed fine bubble liquid production apparatus according to any one of claims 1 to 8,
A deaeration and fine bubble generation process in which both the first pump and the second pump are operated and the inside of the circulation path located between the first pump and the second pump is depressurized. , Deaerated fine bubble liquid production method.   The method for producing a degassed fine bubble liquid according to claim 9, wherein in the degassing and fine bubble generation process, the flow rate of the processing liquid in the circulation path is adjusted within a range of 0.05 to 5.00 m / sec. . The deaeration and fine bubble generation process,
Either the first pump or the second pump is stopped, and the circulation located in the casings of the first pump and the second pump and between the first pump and the second pump. A gas discharging process of discharging gas remaining inside the path,
The method for producing a degassed fine bubble liquid according to claim 9, wherein the method is performed alternately. The time per one time of the deaeration and the fine bubble generation process is in the range of 60 to 3600 seconds,
The method for producing a degassed fine bubble liquid according to claim 11, wherein a time per one gas discharging step is in a range of 1 to 60 seconds. A processing unit that holds a processing liquid for performing a predetermined process on the processing target, and the processing target is filled with the processing liquid,
An ultrasonic wave application mechanism provided in the processing unit and applying ultrasonic waves to the object to be processed,
The deaerated fine bubble liquid producing apparatus according to any one of claims 1 to 8, which is provided for the processing unit,
An ultrasonic treatment device comprising: A processing unit that holds a processing liquid for performing a predetermined process on the processing object, the processing unit being filled with the processing liquid, and the processing unit; An ultrasonic processing apparatus comprising at least an ultrasonic application mechanism for applying pressure and an apparatus for producing a degassed fine bubble liquid according to any one of claims 1 to 8, which is provided for the processing unit. Sonication method,
Both the first pump and the second pump are in the operating state, and the deaeration and the fine bubble generation process of depressurizing the inside of the circulation path located between the first pump and the second pump, Producing the degassed fine bubble liquid,
An ultrasonic processing method, wherein an ultrasonic wave is applied from the ultrasonic applying mechanism to the object to be processed while supplying the manufactured degassed fine bubble liquid to the processing unit.   The ultrasonic treatment method according to claim 14, wherein the flow rate of the treatment liquid in the circulation path is adjusted within a range of 0.05 to 5.00 m / sec in the degassing and fine bubble generation process. The deaeration and fine bubble generation process,
Either the first pump or the second pump is stopped, and the circulation located in the casings of the first pump and the second pump and between the first pump and the second pump. The ultrasonic treatment method according to claim 14 or 15, wherein the degassing fine bubble liquid is produced by alternately performing a gas discharging step of discharging gas remaining inside the path. The time per one time of the deaeration and the fine bubble generation process is in the range of 60 to 3600 seconds,
17. The ultrasonic treatment method according to claim 16, wherein a time per one time of the gas discharging step is in a range of 1 to 60 seconds.

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