JP6277973B2 - Bubble diameter distribution measuring method and bubble diameter distribution measuring apparatus - Google Patents

Description

  The present invention relates to a bubble diameter distribution measuring method and a bubble diameter distribution measuring apparatus for measuring the bubble diameter distribution of fine bubbles contained in a liquid sample.

  In recent years, research and use of fine bubbles such as micro bubbles and ultra fine bubbles have been actively conducted. Fine bubbles are fine bubbles having a bubble diameter of 100 μm or less, for example, those having a bubble diameter of 1 μm or more are called microbubbles, and those having a bubble diameter of less than 1 μm are called ultrafine bubbles. Fine bubbles have a characteristic that the residence time in the liquid is long. In particular, it is known that ultra fine bubbles stay in the liquid for several months.

  Fine bubbles are expected to have various effects such as a cleaning effect and a sterilizing effect. For example, if various facilities are cleaned using fine bubbles in factories, plants, public toilets, etc., the amount of detergent used can be reduced. Therefore, a cleaning method using fine bubbles has attracted attention as a new environmentally friendly cleaning method.

  The relationship between the characteristics and effects of the fine bubbles as described above depends on the bubble diameter and bubble amount (concentration) of the fine bubbles. Therefore, a technique for measuring the bubble size distribution (particle size distribution) of fine bubbles using a laser diffraction / scattering type particle size distribution measuring apparatus or the like has been proposed (for example, see Patent Document 1 below).

  However, the liquid sample to be measured may contain solid particles such as dust or soil, and liquid particles such as oil or emulsion, in addition to fine bubbles. In such a case, the method of measuring the bubble size distribution of fine bubbles using a particle size distribution measuring device cannot distinguish between fine bubbles, solid particles and liquid particles, and the bubble size of fine bubbles. The distribution may not be measured accurately.

  As a method for discriminating bubbles and solid fine particles contained in a liquid sample, for example, a method of periodically changing the volume of bubbles by applying a pressure wave by ultrasonic vibration to the liquid has been proposed (for example, See Patent Document 2 below).

JP 2007-263876 A JP-A-63-139231

  However, the configuration disclosed in Patent Document 2 is a configuration in which a liquid sample is allowed to flow in a sample cell at a constant flow rate and it is confirmed that the volume of bubbles periodically changes when passing through a measurement area. It is necessary to check each bubble individually. Therefore, even if the configuration disclosed in Patent Document 2 is used, it is difficult to accurately measure the bubble size distribution of fine bubbles in the liquid sample in a short time.

  The present invention has been made in view of the above circumstances, and an object thereof is to provide a bubble diameter distribution measuring method and a bubble diameter distribution measuring apparatus capable of accurately measuring the bubble diameter distribution of fine bubbles in a short time. To do.

The bubble diameter distribution measuring method according to the present invention includes an accommodation step, a first data acquisition step, a second data acquisition step, and a bubble diameter distribution calculation step. In the storing step, a liquid sample containing fine bubbles is stored in a container. In the first data acquisition step, data relating to the particle size distribution of the liquid sample in the container is acquired in a state where the inside of the container is at a first pressure. In the second data acquisition step, data relating to the particle size distribution of the liquid sample in the container is acquired in a state where the inside of the container is at a second pressure different from the first pressure. In the bubble diameter distribution calculating step, based on the data acquired in the first data acquiring step and the data acquired in the second data acquiring step, the first pressure and the second pressure are calculated . By calculating using the change amount, the bubble diameter distribution of the fine bubbles contained in the liquid sample is calculated.

According to such a configuration, it is possible to obtain data on the particle size distribution of the liquid sample in the container at each pressure with different pressures in the container, and calculate using the amount of change in pressure based on the data. By performing the above, it is possible to calculate the bubble size distribution of the fine bubbles contained in the liquid sample. That is, the bubble diameter of the fine bubble contained in the liquid sample can be changed by setting the inside of the container to different pressures. On the other hand, the particle diameters of the solid particles and liquid particles contained in the liquid sample hardly change according to the pressure. Therefore, only the bubble size distribution of the fine bubbles can be specified by comparing the data related to the particle size distribution of the liquid samples acquired at different pressures.

  Since there is a fixed relationship between the amount of change in pressure and the amount of change in bubble size of fine bubbles, the bubble size distribution of fine bubbles can be calculated accurately by performing calculations using the amount of change in pressure. Can do. Therefore, it is possible to accurately measure the bubble size distribution of fine bubbles in a short time simply by acquiring data on the particle size distribution of the liquid sample at different pressures and comparing the data.

  The data regarding the particle size distribution may be particle size distribution data or data for calculating the particle size distribution data.

  According to such a configuration, the bubble size distribution of fine bubbles contained in the liquid sample can be measured based on the particle size distribution data acquired at different pressures or the data for calculating the particle size distribution data. . That is, not only can the bubble size distribution of fine bubbles be measured based on the finally calculated particle size distribution data, but also based on data used to calculate the particle size distribution data such as light intensity distribution data. It is also possible to measure the bubble size distribution of fine bubbles.

The amount of change in the bubble diameter distribution calculating step may be a pressure difference or a pressure ratio .

  According to such a configuration, the bubble diameter distribution of the fine bubbles is accurately measured by performing calculation using the pressure difference or pressure ratio between the first pressure and the second pressure as the amount of change in pressure. be able to.

The bubble size distribution measuring apparatus according to the present invention includes a container, a pressure control unit, a first data acquisition unit, a second data acquisition unit, and a bubble size distribution calculation unit. The container contains a liquid sample containing fine bubbles. The pressure control unit controls the pressure in the container. The first data acquisition unit acquires data relating to the particle size distribution of the liquid sample in the container in a state where the inside of the container is at a first pressure. The second data acquisition unit acquires data relating to the particle size distribution of the liquid sample in the container in a state where the inside of the container is set to a second pressure different from the first pressure. The bubble diameter distribution calculation unit is configured to calculate the first pressure and the second pressure based on the data acquired by the first data acquisition unit and the data acquired by the second data acquisition unit . By calculating using the change amount, the bubble diameter distribution of the fine bubbles contained in the liquid sample is calculated.
And the data regarding the said particle diameter distribution based on the said bubble diameter distribution calculation part may be data for calculating particle diameter distribution data or particle diameter distribution data.

The amount of change used by the bubble diameter distribution calculation unit may be a pressure difference or a pressure ratio .

  According to the present invention, it is possible to accurately measure the bubble size distribution of fine bubbles in a short time simply by acquiring data related to the particle size distribution of a liquid sample at different pressures and comparing the data.

It is the figure which showed the structural example of the bubble diameter distribution measuring apparatus which concerns on one Embodiment of this invention. It is the block diagram which showed an example of the electrical constitution of a bubble diameter distribution measuring apparatus. It is a figure for demonstrating the aspect at the time of measuring the bubble diameter distribution of a fine bubble, and has shown an example of the particle diameter distribution data acquired by the 1st data acquisition part. It is a figure for demonstrating the aspect at the time of measuring the bubble diameter distribution of a fine bubble, and has shown an example of the particle diameter distribution data acquired by the 2nd data acquisition part. It is a figure for demonstrating the aspect at the time of measuring the bubble diameter distribution of a fine bubble, and has shown an example of the bubble diameter distribution data calculated by the bubble diameter distribution calculation part. It is a figure for demonstrating the aspect at the time of calculating the bubble diameter distribution of a fine bubble. It is the flowchart which showed the flow at the time of measuring the bubble diameter distribution of the fine bubble contained in a liquid sample.

  FIG. 1 is a diagram showing a configuration example of a bubble diameter distribution measuring apparatus according to an embodiment of the present invention. This bubble size distribution measuring device is, for example, a laser diffraction / scattering particle size distribution measuring device. That is, in this embodiment, the bubble size distribution (particle size distribution) of the gas particles contained in the liquid sample is measured using a particle size distribution measuring device for measuring the particle size distribution of the solid particles and the liquid particles. .

  The liquid sample is a sample that uses any liquid such as alcohol or oil as a medium in addition to water, for example, and includes fine bubbles made of fine bubbles having a bubble diameter of 100 μm or less, for example. Specifically, at least one of ultrafine bubbles having a bubble diameter of less than 1 μm and microbubbles having a bubble diameter of 1 μm or more is contained in the liquid sample as gas particles. The gas constituting the gas particles may be air or a gas other than air, such as ozone or hydrogen.

  The bubble diameter distribution measuring apparatus according to the present embodiment includes a light intensity measuring unit 1 that irradiates a liquid sample with laser light and measures the intensity of diffraction / scattered light (laser diffraction / scattered light) from the liquid sample. Is provided. The light intensity measuring unit 1 includes a light source 11, a condensing lens 12, a spatial filter 13, a collimator lens 14, a sample cell 15, a condensing lens 16, a photodiode array 17, a side sensor 18, a plurality of rear sensors 19, and the like. Is provided. A liquid sample to be measured is supplied to the sample cell 15 for each measurement. That is, the sample cell 15 used in the present embodiment is a so-called batch cell.

  The light source 11 is composed of, for example, a laser light source, and the laser light emitted from the light source 11 becomes parallel light by passing through the condenser lens 12, the spatial filter 13, and the collimator lens 14. The laser light thus converted into parallel light is irradiated onto the sample cell 15 in which the liquid sample is accommodated, and includes a particle group (solid particles, liquid particles, and gas particles) included in the sample in the sample cell 15. ), The light is received by the photodiode array 17 through the condenser lens 16.

  The photodiode array 17 is disposed in front of the sample cell 15 (on the side opposite to the light source 11 side) when viewed from the light source 11 side. Accordingly, the plurality of light receiving elements provided in the photodiode array 17 constitute a front sensor 171. The photodiode array 17 constitutes a detector for detecting diffracted / scattered light (diffracted light and scattered light) from the liquid sample in the sample cell 15.

  The photodiode array 17 in the present embodiment includes a plurality of (for example, 64) front sensors 171 formed with ring-shaped or semi-ring-shaped detection surfaces having different radii, and the optical axis of the condenser lens 16 as the center. The ring detectors are arranged in a concentric circle shape, and light having diffraction and scattering angles corresponding to the respective positions is incident on each front sensor 171. Therefore, the detection signal of each front sensor 171 of the photodiode array 17 represents the intensity of light at each diffraction / scattering angle.

  On the other hand, the side sensor 18 is arranged on the side of the sample cell 15 when viewed from the light source 11 side. In this example, the sample cell 15 is formed of a thin hollow member, and the thickness direction D is arranged so as to be parallel to the optical axis L of the laser light incident from the light source 11. The side sensor 18 is arranged with respect to the sample cell 15 in a direction orthogonal to the thickness direction D, for example.

  In FIG. 1, the side sensor 18 is disposed above the sample cell 15. However, the present invention is not limited to this, and the surface perpendicular to the thickness direction D of the sample cell 15, such as below, right, and left of the sample cell 15. You may arrange | position in arbitrary positions. Accordingly, the side sensor 18 can receive diffracted / scattered light in a direction orthogonal to the thickness direction D. However, the side sensor 18 is not limited to a configuration that receives diffracted / scattered light in a direction of 90 ° with respect to the thickness direction D, but is 70 ° to 110 ° with respect to the thickness direction D, and more preferably 80 °. It may be configured to receive diffracted / scattered light in the direction of ° to 100 °.

  The plurality of rear sensors 19 are respectively disposed behind the sample cell 15 (on the light source 11 side) when viewed from the light source 11 side. Thereby, each rear sensor 19 can receive diffracted / scattered light backward from the side sensor 18. The rear sensors 19 are arranged at different angles with respect to the sample cell 15, thereby receiving diffracted / scattered light incident at different angles. In this example, two rear sensors 19 are provided, but the configuration is not limited to this, and for example, one or three or more rear sensors 19 may be provided.

  The detection signals of the front sensors 171, the side sensors 18, and the rear sensors 19 of the photodiode array 17 are converted from analog signals to digital signals by the A / D converter 3, and then processed through the communication unit 4. It is input to the device 5. Thereby, the received light intensity in each of the sensors 171, 18, 19 is input to the data processing device 5 in association with the element number of each of the sensors 171, 18, 19.

  The data processing device 5 is for processing data when measuring the particle size distribution of the liquid sample, and is constituted by a personal computer, for example. The data processing device 5 includes a control unit 51, an operation unit 52, a display unit 53, a storage unit 54, and the like. The data processing device 5 may constitute a bubble diameter distribution measuring device integrally with the light intensity measuring unit 1 or the like, or may be provided as a bubble diameter distribution measuring device separated from the light intensity measuring unit 1 or the like. Good.

  The control unit 51 includes, for example, a CPU (Central Processing Unit), and each unit such as an operation unit 52, a display unit 53, and a storage unit 54 is electrically connected. The operation unit 52 is configured to include, for example, a keyboard and a mouse, and an operator can perform an input operation and the like by operating the operation unit 52.

  The display unit 53 can be configured by, for example, a liquid crystal display, and the operator can perform work while confirming the display content of the display unit 53. The storage unit 54 can be configured by, for example, a ROM (Read Only Memory), a RAM (Random Access Memory), a hard disk, and the like.

The particle size distribution data of the liquid sample is generated by the control unit 51 performing calculations based on the light intensity distribution data obtained by measuring the liquid sample in the light intensity measurement unit 1. When generating the particle size distribution data, the relationship of the following formula (1) can be used.

Here, s, q, and A are represented by the following formulas (2) to (4).

The s is light intensity distribution data (vector). Each element s _i (i = 1, 2,..., M) in s is a detection intensity in each front sensor 171, side sensor 18, and each rear sensor 19 of the photodiode array 17.

The q is particle size distribution data (vector) expressed as a frequency distribution%. When the particle size range to be measured (maximum particle size is x ₁ , minimum particle size is x _{n + 1} ) is divided into n and each particle size interval is [x _j , x _{j + 1} ], each element q _{j in} q above (J = 1, 2,..., N) is the amount of particles corresponding to each particle diameter section [x _j , x _{j + 1} ].

Usually, a volume standard is used, and normalization is performed so that the following formula (5) is satisfied, that is, the total of each element q _j is 100%.

A is a coefficient matrix for converting the particle size distribution data q into light intensity distribution data s. Each element a _{i, j} (i = 1, 2,..., M, j = 1, 2,..., N) in A is a unit belonging to each particle diameter section [x _j , x _{j + 1} ]. This is the detected intensity at the i-th element of light diffracted and scattered by a particle group having a particle amount.

The value of each element a _{i, j in} A can be theoretically calculated in advance using the refractive index as one of the parameters. At this time, the value of each element a _{i, j} may be calculated using the refractive index of the gas constituting the gas particle. The value of each element a _{i, j} is calculated using Fraunhofer diffraction theory or Mie scattering theory. For example, when the particle diameter is sufficiently larger than the wavelength of the laser beam from the light source 11 (for example, 10 times or more), the value of each element a _{i, j} can be calculated using Fraunhofer diffraction theory. On the other hand, when the particle diameter is the same as or smaller than the wavelength of the laser beam from the light source 11 _, the value of each element a _{i, j} can be calculated using the Mie scattering theory.

Thus, if the value of each element a _{i, j in} A is obtained, the particle size distribution data q can be obtained by the following equation (6) based on the equation (1). Where ^AT is a transposed matrix of A.

  In the present embodiment, a liquid sample containing fine bubbles is accommodated in a sample cell 15 as a container, and the pressure in the sample cell 15 changes according to the operation of the pressure adjustment mechanism 6. The pressure adjustment mechanism 6 includes, for example, a syringe 61 that communicates with the sample cell 15 and a syringe drive unit 62 that drives the syringe 61. The syringe drive unit 62 includes, for example, a motor (not shown), and can drive the syringe 61 to pressurize or depressurize the sample cell 15.

  FIG. 2 is a block diagram showing an example of the electrical configuration of the bubble diameter distribution measuring apparatus. The control unit 51 includes, for example, a CPU (Central Processing Unit), and when the CPU executes a program, the pressure control unit 511, the first data acquisition unit 512, the second data acquisition unit 513, and the bubble diameter distribution. It functions as a calculation unit 514, a display control unit 515, and the like.

  The pressure control unit 511 controls the pressure in the sample cell 15 by controlling the operation of the syringe driving unit 62 to drive the syringe 61. The first data acquisition unit 512 and the second data acquisition unit 513 each acquire particle size distribution data based on the input signal from the light intensity measurement unit 1. The particle size distribution data acquired by the first data acquisition unit 512 and the second data acquisition unit 513 are stored in the storage unit 54, respectively.

  In the present embodiment, when the particle size distribution data is acquired by the first data acquisition unit 512 and when the particle size distribution data is acquired by the second data acquisition unit 513, the pressure in the sample cell 15 is different. Further, the pressure control unit 511 controls the pressure in the sample cell 15. Specifically, when the particle size distribution data is acquired by the first data acquisition unit 512, the inside of the sample cell 15 is set to atmospheric pressure (first pressure), and the particle size distribution data is acquired by the second data acquisition unit 513. Is obtained, the inside of the sample cell 15 is set to a pressure higher than the atmospheric pressure (second pressure). The second pressure is set to, for example, 2 to 4 times (2 to 4 atmospheres) the first pressure, but is not limited thereto.

  The bubble diameter distribution calculation unit 514 is a fine bubble included in the liquid sample based on the particle size distribution data acquired by the first data acquisition unit 512 and the particle size distribution data acquired by the second data acquisition unit 513. The bubble diameter distribution is calculated. That is, by obtaining the particle size distribution data of the liquid sample in the sample cell 15 at different pressures in the sample cell 15, the fine bubbles contained in the liquid sample based on the particle size distribution data are obtained. The bubble diameter distribution is calculated.

  The display control unit 515 controls display contents on the display unit 53. When the bubble diameter distribution of the fine bubbles contained in the liquid sample is calculated by the bubble diameter distribution calculation unit 514, the display control unit 515 causes the display unit 53 to display the bubble diameter distribution on a graph or the like.

  FIG. 3A to FIG. 3C are diagrams for explaining an aspect when measuring the bubble size distribution of fine bubbles. FIG. 3A is an example of the particle size distribution data acquired by the first data acquisition unit 512, and the relationship between the particle size and the particle amount of solid particles and liquid particles contained in the liquid sample and the liquid sample includes The relationship between the bubble diameter of each gas particle and the amount of bubbles is shown. FIG. 3B is an example of the particle size distribution data acquired by the second data acquisition unit 513, and includes the relationship between the particle size and the amount of solid particles and liquid particles contained in the liquid sample, and the liquid sample. The relationship between the bubble diameter of each gas particle and the amount of bubbles is shown. FIG. 3C is an example of the bubble diameter distribution data calculated by the bubble diameter distribution calculation unit 514, and shows the relationship between each bubble diameter of the gas particles contained in the liquid sample and the amount of bubbles. 3A to 3C, the horizontal axis represents the particle diameter or the bubble diameter in logarithm.

  Assume that the particle size distribution data acquired by the first data acquisition unit 512 in a state where the inside of the sample cell 15 is set to the first pressure is, for example, data as shown in FIG. 3A. Assuming that fine bubbles and solid particles or liquid particles are contained in the liquid sample, as shown in FIG. 3A, fine bubble particle size distribution (bubble size distribution) D1, solid particles or liquid particles And a particle size distribution D2 appear in the data.

  When the particle size distribution data is acquired by the second data acquisition unit 513 with the second pressure higher than the first pressure in the sample cell 15 in which such a liquid sample is stored, for example, FIG. Data as shown in 3B is obtained. As is clear from the comparison of the fine bubble particle size distribution D1 in FIGS. 3A and 3B, the bubble diameter (particle size) of the fine bubbles contained in the liquid sample is changed by setting the inside of the sample cell 15 to a different pressure. Can be made.

  That is, when the inside of the sample cell 15 is pressurized, the bubble diameter of the fine bubbles is reduced, so the fine bubble particle size distribution D1 is shifted to the smaller bubble diameter in the case of FIG. 3B than in the case of FIG. 3A. It becomes a state. On the other hand, as apparent from comparing the particle size distribution D2 of the solid particles or the liquid particles in FIGS. 3A and 3B, the particle size of the solid particles or the liquid particles contained in the liquid sample is almost equal to the pressure. It does not change. By comparing the particle size distributions D1 and D2 using such characteristics, only the bubble size distribution D1 of the fine bubbles can be specified as shown in FIG. 3C.

Since there is a fixed relationship between the amount of change in pressure and the amount of change in bubble size of fine bubbles, the bubble size distribution of fine bubbles can be calculated accurately by performing calculations using the amount of change in pressure. Can do. Specifically, when the pressure is increased by n times, the fine bubble volume is increased by n ⁻¹ times, and the bubble diameter is increased by n ^{− (1/3)} times. Therefore, the amount of change in the bubble diameter of the fine bubble is specified using the amount of change from the first pressure to the second pressure (for example, pressure difference or pressure ratio), and the amount of change in the bubble diameter is used to determine the first amount. By simply comparing the particle size distributions D1 and D2 at the pressure and the second pressure, the bubble size distribution D2 of the fine bubbles can be accurately measured in a short time.

  For example, when only the fine bubble bubble size distribution D1 as shown in FIG. 3C is specified from the particle size distributions D1 and D2 as shown in FIGS. 3A and 3B, the particle size of FIG. 3A is determined from the particle size distribution data of FIG. 3B. Performs calculation to subtract distribution data. Thereby, the particle size distribution D2 of the solid particles or the liquid particles is erased by calculation, and the difference between the bubble size distribution D1 in FIG. 3A and the bubble size distribution D1 in FIG. 3B is obtained.

  In this case, if the bubble diameter distribution D1 of FIG. 3A and the bubble diameter distribution D1 of FIG. 3B do not overlap each other in a part of the bubble diameter range, the bubble diameter distribution D1 influences each other by the above calculation. Therefore, one bubble diameter distribution D1 can be easily taken out and used as a measurement result.

  On the other hand, when the bubble diameter distribution D1 of FIG. 3B overlaps in the partial bubble diameter range L2 with respect to the bubble diameter range L1 of the bubble diameter distribution D1 of FIG. The above operations affect each other. Therefore, when the above difference calculation is performed, a measurement result different from the actual bubble diameter distribution is obtained in the overlapping bubble diameter range L2. FIG. 4 is a diagram for explaining an aspect when calculating the bubble diameter distribution D2 of the fine bubbles in such a case. The bubble diameter distribution D1 is measured by being divided into five sections. The bubble diameter distribution at the first pressure (corresponding to FIG. 3A) and the bubble diameter distribution at the second pressure (corresponding to FIG. 3B). Assume that the shift amount is for two sections. Since the data of FIG. 3A is subtracted from the data of FIG. 3B, FIG. 4 shows the data of FIG. 3B on the positive side of the graph and the data of FIG. 3A on the negative side of the graph. The fact that the particle size distribution D2 of the solid particles or liquid particles is erased by the difference calculation is the same as described above.

In the example of FIG. 4, the bubble diameter distribution D1 (−x ₁ , −x ₂ , −x) of FIG. 3A subtracted from the bubble diameter distribution D1 (x ₁ , x ₂ , x ₃ , x ₄ , x ₅ ) of FIG. 3B. ₃ , −x ₄ , −x ₅ ) partially overlap. Therefore, the bubble amounts x ₁ and x _{2 at} the bubble diameters a ₁ and a ₂ are equal to the actual values, but the bubble amounts at the bubble diameters a ₃ , a ₄ , a ₅ , a ₆ and a ₇ are different from the actual values. ing. In this case, the bubble amounts at the bubble diameters a ₃ , a ₄ , a ₅ , a ₆ , and a ₇ are calculated as follows by the above-described difference calculation.
The amount of bubbles is calculated in cell diameter _{a 3 =} x ₃ -x ₁
The amount of bubbles is calculated in cell diameter _{a 4 =} x ₄ -x ₂
The amount of bubbles is calculated in cell diameter _{a 5 =} x ₅ -x ₃
The amount of bubbles is calculated in cell diameter _{a 6} = -x ₄
The amount of bubbles is calculated in cell diameter _{a 7} = -x ₅

In order to correct the bubble amount in the bubble diameters a ₃ , a ₄ , a ₅ , a ₆ , and a ₇ calculated by the above calculation to an actual value, the bubble diameter distribution calculation unit 514 performs the following calculation. Is called.
The actual amount of bubbles in the bubble size _{a 3 = (x 3 -x 1} ) + x 1 = x 3
The actual amount of bubbles in the bubble size _{a 4 = (x 4 -x 2} ) + x 2 = x 4
The actual amount of bubbles in the bubble size _{a 5 = (x 5 -x 3} ) + x 3 = x 5
The actual amount of bubbles in the bubble size _{a 6 = (- x 4)} + x 4 = 0
The actual amount of bubbles in the bubble diameter _{a 7 = (- x 5)} + x 5 = 0

That is, using the actual amount of bubbles _x 1, _{x 2} in the cell diameter _a 1, _{a 2,} sequentially obtains the actual bubble quantity _x 3, _{x 4} in cell diameter _a 3, _{a 4,} their amount of bubbles _{x 3} , with _{x 4,} it is possible to determine the actual amount of bubbles in the next cell diameter _{a 5, a 6, a 7} sequentially. Thus, if the amount of change (pressure difference or pressure ratio) from the first pressure (see FIG. 3A) to the second pressure (see FIG. 3B) is known, the amount of change in the bubble diameter can be calculated from the amount of change. As can be seen, since the shift amount of the bubble diameter from FIG. 3A to FIG. 3B is known, the bubble diameter distribution of the fine bubbles can be accurately calculated by the above calculation.

  Thereby, the relationship between the effect expected for fine bubbles such as washing, sterilization or bioactivation and the bubble size distribution of the fine bubbles can be quantitatively evaluated. In addition, it is possible to specify the bubble size distribution of the fine bubble most suitable for the purpose and target, and to contribute to the establishment of an authentication system related to the fine bubble.

  However, as shown in FIG. 4, when the bubble diameter distribution D1 of FIG. 3A overlaps with the bubble diameter range L1 of the bubble diameter distribution D1 of FIG. For example, the pressure is feedback-controlled so that the bubble diameter distribution D1 in FIG. 3A and the bubble diameter distribution D1 in FIG. 3B do not overlap with each other. It may be a simple configuration.

  FIG. 5 is a flowchart showing the flow when measuring the bubble size distribution of fine bubbles contained in a liquid sample. When measuring the bubble size distribution, first, a liquid sample containing fine bubbles is stored in the sample cell 15 (step S101: storage step). At this time, the inside of the sample cell 15 is atmospheric pressure (first pressure), and the particle size distribution data is acquired as it is (step S102: first data acquisition step). Thereby, particle size distribution data as illustrated in FIG. 3A is obtained.

  Thereafter, the inside of the sample cell 15 is pressurized using the syringe 61 (step S103: pressurization step), and particle size distribution data is acquired in a pressurized state (second pressure) (step S104: second data acquisition). Step). Thereby, particle size distribution data as illustrated in FIG. 3B is obtained. Based on each particle size distribution data obtained as described above, calculation is performed by the bubble size distribution calculation unit 514 to calculate the bubble size distribution of the fine bubbles contained in the liquid sample (step S105: bubbles). Diameter distribution calculation step).

  However, as in the above embodiment, the bubble size distribution is measured based on other data related to the particle size distribution, not limited to the configuration in which the bubble size distribution is measured based on the particle size distribution data acquired at different pressures. Such a configuration may be adopted. That is, not only can the bubble size distribution of fine bubbles be measured based on the finally calculated particle size distribution data, but also based on data used to calculate the particle size distribution data such as light intensity distribution data. It is also possible to measure the bubble size distribution of fine bubbles. The data for calculating the particle size distribution data is not limited to the light intensity distribution data but may be other data calculated from the light intensity distribution data.

  The pressure adjustment mechanism 6 is not limited to the configuration provided with the syringe 61, and may be configured such that the pressure in the sample cell 15 can be adjusted using another mechanism such as a pump. Further, if the configuration is such that data relating to the particle size distribution of the liquid sample in the sample cell 15 at each pressure is obtained with the inside of the sample cell 15 at different pressures, the first pressure is atmospheric pressure, The configuration is not limited to a configuration in which the pressure of 2 is higher than the atmospheric pressure.

  For example, the first pressure is not limited to atmospheric pressure, and may be lower than atmospheric pressure or higher than atmospheric pressure. Further, the second pressure is not limited to a pressure higher than the first pressure, and may be a pressure lower than the first pressure. In this case, the pressure adjustment mechanism 6 may be configured to reduce the pressure in the sample cell 15.

  The container in which the liquid sample containing fine bubbles is stored is not limited to the sample cell 15 made of a batch cell, but may be a sample cell 15 made of a flow cell, for example. In this case, if the liquid sample is introduced into the flow cell at a high pressure, the inside of the flow cell can be pressurized. Further, the configuration is not limited to the sample cell 15 and may be configured such that the liquid sample is accommodated in another container and the bubble diameter distribution of the fine bubbles contained in the liquid sample in the container can be measured.

  In the above embodiment, the case where the bubble diameter distribution measuring device is a laser diffraction / scattering particle size distribution measuring device has been described. However, the present invention can also be applied to a configuration in which the particle size distribution is measured by a method other than the laser diffraction / scattering method. Examples of methods other than the laser diffraction / scattering method include a dynamic light scattering method and an electrical detection band method.

DESCRIPTION OF SYMBOLS 1 Light intensity measurement part 3 A / D converter 4 Communication part 5 Data processing apparatus 6 Pressure adjustment mechanism 11 Light source 12 Condensing lens 13 Spatial filter 14 Collimator lens 15 Sample cell 16 Condensing lens 17 Photodiode array 18 Side sensor 19 Rear sensor 51 Control unit 52 Operation unit 53 Display unit 54 Storage unit 61 Syringe 62 Syringe drive unit 171 Front sensor 511 Pressure control unit 512 First data acquisition unit 513 Second data acquisition unit 514 Bubble diameter distribution calculation unit 515 Display control unit

Claims (6)

An accommodating step for accommodating a liquid sample containing fine bubbles in a container;
A first data acquisition step of acquiring data relating to a particle size distribution of a liquid sample in the container in a state where the inside of the container is at a first pressure;
A second data acquisition step of acquiring data relating to a particle size distribution of a liquid sample in the container in a state where the inside of the container is set to a second pressure different from the first pressure;
Based on the data acquired in the first data acquisition step and the data acquired in the second data acquisition step, calculation is performed using the amount of change between the first pressure and the second pressure. And a bubble diameter distribution calculating step of calculating a bubble diameter distribution of fine bubbles contained in the liquid sample.   The method for measuring a bubble size distribution according to claim 1, wherein the data related to the particle size distribution is particle size distribution data or data for calculating the particle size distribution data. The amount of change, the bubble size distribution measuring method according to claim 1 or 2, characterized in that a pressure difference or pressure ratio. A container for storing a liquid sample containing fine bubbles;
A pressure controller for controlling the pressure in the container;
A first data acquisition unit for acquiring data relating to a particle size distribution of a liquid sample in the container in a state where the inside of the container is at a first pressure;
A second data acquisition unit for acquiring data relating to the particle size distribution of the liquid sample in the container in a state where the inside of the container is set to a second pressure different from the first pressure;
Based on the data acquired by the first data acquisition unit and the data acquired by the second data acquisition unit, calculation is performed using the amount of change between the first pressure and the second pressure. it makes bubble size distribution measuring apparatus characterized by comprising a cell diameter distribution calculating unit for calculating a bubble diameter distribution of the fine bubbles contained in the liquid sample.   The bubble diameter distribution measuring apparatus according to claim 4, wherein the data relating to the particle diameter distribution is particle diameter distribution data or data for calculating the particle diameter distribution data. The amount of change, the bubble size distribution measuring apparatus according to claim 4 or 5, characterized in that a pressure difference or pressure ratio.

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