JP4074492B2 - Particle size distribution measuring device - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an improvement of a particle size distribution measuring apparatus.
[0002]
[Prior art]
One of the particle size distribution measuring devices is equipped with a measurement circulation system in which a dispersion bath, a flow cell, and a circulation pump, in which a sample is dispersed in a dispersion medium and connected as a sample liquid, are connected via a circulation channel. In some cases, a sample liquid is supplied to the flow cell with laser light, and particle size distribution measurement is performed using a light diffraction or scattering phenomenon caused by particles in the sample liquid.
[0003]
By the way, in the above particle size distribution measuring apparatus, when the measurement on a certain sample is completed, the on-off valve attached to the measurement circulation system is opened to drain the sample liquid, and then the on-off valve is closed and the inside of the measurement circulation system is washed with the cleaning liquid. It is used to wash and open the on-off valve again to drain the washed liquid and prepare for the next sample measurement.
[0004]
[Problems to be solved by the invention]
However, in the conventional particle size distribution measuring apparatus, when the sample water existing in the measurement circulation system or the wash water after washing is discharged from the measurement circulation system as waste liquid after the measurement is completed, the so-called natural discharge form is taken. In this case, when the tip of the drainage hose is immersed in the drainage in the drainage channel outside the device or when the hose is long, it takes time to drain the waste liquid. It takes time until the measurement, and particularly when many samples are continuously measured, the desired measurement cannot be performed efficiently in a short time.
[0005]
This invention was made in consideration of the above-mentioned matters, and its purpose is to efficiently drain the waste liquid after the measurement in the measurement circulation system, and when performing a plurality of measurements continuously, It is an object of the present invention to provide a particle size distribution measuring apparatus capable of efficiently performing a desired measurement in a short time by minimizing the preparation time between one measurement and the next measurement.
[0006]
[Means for Solving the Problems]
In order to achieve the above object, according to the present invention, a particle diameter provided with a measurement circulation system in which a sample is dispersed in a dispersion medium to form a sample solution, a dispersion bath, a flow cell, and a circulation pump are connected via a circulation channel. In the distribution measuring apparatus, a drainage pipe that is thicker and shorter than the pipe of the circulation path is connected to the circulation path of the measurement circulation system, and the drainage pipe is provided with an open / close valve. A waste liquid storage tank is connected to the downstream end of the pipe, and the internal volume of this waste liquid storage tank is used to clean the measurement circulation system after the total amount of sample liquid used for one measurement and the measurement. It is set to be larger than the total of the total amount of cleaning liquids, and an air vent pipe and a drainage flow path are connected to the waste liquid storage tank.
[0007]
In the particle size distribution measuring apparatus, when one measurement is completed, the on- off valve provided in the drain pipe between the measurement circulation system and the waste liquid storage tank is opened, and the sample liquid after measurement existing in the measurement circulation system is opened. Is discharged into a waste liquid storage tank. After the sample liquid is discharged, the on-off valve is closed, the inside of the measurement circulation system is washed with the cleaning liquid, and the liquid used for the cleaning is opened and discharged to the waste liquid storage tank. Thereafter, the on-off valve is closed and the next measurement is waited for. In this way, compared to the conventional case, the waste liquid after measurement can be drained from the measurement circulation system in a short time, so the waiting time until the next measurement is shortened and multiple measurements are performed continuously. In this case, desired measurement can be performed efficiently in a short time. And the waste liquid discharged | emitted by the waste liquid storage tank should just be discharged | emitted suitably to a drainage channel before the next measurement is complete | finished.
[0008]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, the details of the present invention will be described with reference to the drawings. 1 and 2 show one embodiment of the present invention. First, FIG. 1 schematically shows an example of the configuration of a particle size distribution measuring apparatus according to the present invention. In this figure, reference numeral 1 denotes a measuring apparatus body, which is configured as follows. That is, reference numeral 2 denotes a dispersion bath, inside which a stirring blade 4 that is rotated by a motor 3 is provided, and an ultrasonic vibrator 5 that is vibrated by an oscillator is provided outside the bottom thereof. A sample liquid (also referred to as a suspension) 10 is prepared by adjusting particles (for example, powders or granules) 6 as a sample and a dispersion medium 9 supplied from a dispersion medium tank 7 through a dispersion medium supply pipe 8. It is what. Reference numeral 11 denotes an on-off valve such as a normally closed electromagnetic valve provided in the dispersion medium supply pipe 8. A cleaning liquid tank 12 stores the cleaning liquid 13 and supplies the cleaning liquid 13 to the dispersion bath 2 through a cleaning liquid supply pipe 15 having an on-off valve 14 such as a normally closed electromagnetic valve.
[0009]
Reference numeral 16 denotes a flow cell as a sample cell, which is connected to the dispersion bath 2 by a circulation flow path 18 provided with a circulation pump 17, and forms a measurement circulation system 19 together with these members 2, 17 and 18. A drain pipe 21 is connected between the flow cell 16 of the measurement circulation system 19 and the circulation pump 17 via an on-off valve 20 such as a normally closed electromagnetic valve. A waste liquid storage tank 22 is connected to the side. In this case, the drain pipe 21 is considerably thicker than the pipe constituting the circulation flow path 18 and is as short as possible.
[0010]
The waste liquid storage tank 22 is provided, for example, in the measuring apparatus main body 1 and includes an air vent pipe 22a, and a drain flow including an open / close valve 23 such as a normally closed electromagnetic valve and a discharge pump 24 at the bottom thereof. A path 25 is connected. The downstream side of the drainage channel 25 is connected to a drainage channel (not shown) outside the apparatus. The internal volume of the waste liquid storage tank 22 is larger than the total of the total amount of the sample liquid 10 used for one measurement and the total amount of the cleaning liquid 13 used for cleaning the measurement circulation system 19 after the measurement, For example, it is set to a level that can accommodate about five times as much liquid (waste liquid).
[0011]
Reference numeral 26 denotes a laser light source provided on one side of the flow cell 16, reference numerals 27 and 28 denote a condenser lens and a photodetector provided on the other side of the flow cell 16, and the photodetector 28 includes, for example, a plurality of detectors in a ring shape. It comprises a so-called ring detector disposed on the surface, and converts incident scattered light into an electrical signal.
[0012]
Reference numeral 29 denotes a signal switching circuit such as a multiplexer for sequentially switching and outputting electrical signals from the photodetector 28, and 30 denotes an AD converter for converting the electrical signals into digital quantities.
[0013]
Further, reference numeral 31 denotes an arithmetic control device that controls each part of the measuring apparatus main body 1 and performs various calculations, and is a computer such as a personal computer. The computer 31 includes a CPU 32, a ROM 33, a RAM 34, an input device 35 such as a keyboard, a display operation device 36, a printer (not shown), and the like.
[0014]
In the ROM 33, in addition to various control programs, a program for calculating particle size distribution calculation constants using parameters depending on the input sample and dispersion medium, and a particle size distribution based on a particle size distribution calculation constant file. It has a program to find out. In addition, the RAM 34 stores the results of calculation processing by the CPU 32 and information input by the input device 35, and stores various parameters, particle size distribution calculation constant files, and the like. Further, the display operation device 36 is configured to display the processing results of the CPU 32, data stored in the RAM 34, and various input information, and to input control information and the like on the screen in an interactive manner.
[0015]
Next, the operation of the particle size distribution measuring apparatus having the above configuration will be described with reference to FIG. First, a function key “injection” (not shown) on the screen of the display operation device 36 of the computer 31 is operated. As a result, the on-off valve 11 is opened, and an appropriate amount of the dispersion medium 9 is introduced into the dispersion bath 2 (step S1).
[0016]
Then, the function key “circulation” (not shown) on the screen is operated. As a result, the agitation pump 17 operates, the dispersion medium 9 circulates in the measurement circulation system 19 along the circulation flow path 18, and the flow cell 16 is filled with the dispersion medium 9 (step S2).
[0017]
Next, a function key “blank” (not shown) on the screen is operated. As a result, laser light is irradiated from the laser light source 26 to the flow cell 16 filled with the circulating dispersion medium 9, and the amount of scattered (diffracted) light is measured (blank measurement) in the absence of particles. The data at this time is stored in the CPU 32 (step S3).
[0018]
After the blank measurement, an appropriate amount of sample 6 is put into the dispersion bath 2 (step S4).
[0019]
The function key “stirring” (not shown) on the screen is operated. As a result, the motor 3 operates, the stirring blade 4 rotates, and the dispersion medium 7 including the sample 6 is stirred. Along with this operation, a function key “ultrasound” (not shown) on the screen is operated. As a result, the ultrasonic transducer 5 operates to perform ultrasonic dispersion processing so that the sample 6 is uniformly dispersed in the dispersion medium 9, and a predetermined sample liquid 10 is obtained (step S5). Then, simultaneously with the start of the ultrasonic dispersion processing, the function key “circulation” is operated. As a result, the circulation pump 17 operates and the sample solution 10 circulates in the measurement circulation system 19. By irradiating the flow cell 16 with laser light in this state (step S6), the main measurement using the sample liquid 10 is performed.
[0020]
Scattered light generated by the laser beam irradiation is taken into the photodetector 28 (step S6).
[0021]
Then, a signal corresponding to the intensity of the scattered light is output from the photodetector 28, and this signal is input to the CPU 32 via the signal switching circuit 29 and the AD converter 30. In the CPU 32, the particle size distribution calculation is performed in consideration of the data at the time of the blank measurement (step S7).
[0022]
The result of the particle size distribution calculation is displayed on the display screen of the display operation device 36 as a particle size distribution graph (step S8).
[0023]
After the desired measurement is performed, by operating a function key “drain” (not shown) on the screen, the on-off valve 20 is opened (step S9), and the sample liquid 10 in the measurement circulation system 19 is All are discharged (step S10) and stored in the waste liquid storage tank 22 through the drain pipe 21. In this case, the drain pipe 21 is thicker and shorter than the circulation flow path 18 in the measurement circulation system 19 and the waste liquid storage tank 22 is provided with an air vent pipe 22a. 10 is discharged from the measurement circulation system 19 at once (rapidly).
[0024]
Thereafter, by operating a function key “wash” (not shown) on the screen, the on-off valve 20 is closed (step S11) and the on-off valve 14 is opened. When the on-off valve 14 is opened, the cleaning liquid 13 is supplied from the cleaning liquid tank 12 to the measurement circulation system 19 via the dispersion bath 2 and is circulated to clean all parts in the measurement circulation system 19. (Step S12).
[0025]
When the cleaning is finished, the on-off valve 14 is closed and the on-off valve 20 is opened (step S13), and all the cleaning liquid 13 in the measurement circulation system 19 is discharged (step S14), and the waste liquid storage tank passes through the drain pipe 21. 22 is stored. The cleaning liquid 13 is quickly discharged from the measurement circulation system 19 for the same reason as the discharging of the sample liquid 10. Thereafter, the on-off valve 20 is closed (step S15), and a standby state for the next measurement is entered.
[0026]
And the waste liquid such as the sample liquid 10 and the cleaning liquid 13 after the measurement discharged into the waste liquid storage tank 22 is temporarily stored in the waste liquid storage tank 22, and this waste liquid is stored until the next measurement. Even if the waste liquid is slowly discharged from the waste liquid storage tank 22 to the drainage channel (not shown) outside the apparatus via the drainage channel 25, the cleaning is performed without any trouble in the next measurement. The sample solution 10 is newly supplied to the measured circulation system 19 and is circulated to perform a blank measurement or a main measurement.
[0027]
As described above, in the particle size distribution measuring apparatus in the above embodiment, when one measurement is completed, the waste liquid such as the sample liquid 10 used for the measurement or the cleaning liquid 13 used for cleaning the measurement circulation system 19 is removed. Instead of directly discharging directly to the drainage channel outside the apparatus as in the prior art, the measurement circulation system 19 is made as much as possible by discharging it into the waste liquid storage tank 22 provided in the apparatus 1 at once. Because it is in a standby state for the next measurement in a short time, when multiple measurements are performed continuously, the preparation time between the measurements can be shortened, and multiple measurements can be performed continuously. Thus, the desired measurement can be efficiently performed in a short time.
[0028]
In the particle size distribution measuring apparatus, the drain pipe 21 connecting the measurement circulation system 19 and the waste liquid storage tank 22 is thicker and shorter than the circulation flow path 18 of the measurement circulation system 19. Since the waste liquid in the measurement circulation system 19 can be discharged all at once, and the air vent pipe 22a is provided in the waste liquid storage tank 22, the air and liquid in the waste liquid storage tank 22 are used. And the waste liquid is discharged from the measurement circulation system very quickly.
[0029]
The waste liquid temporarily stored in the waste liquid storage tank 22 is discharged to the drainage channel outside the apparatus by opening the on-off valve 23 provided in the drainage channel 25 and operating the discharge pump 24. The on-off valve 23 and the discharge pump 24 are not necessarily provided. Further, instead of the discharge pump 24, air may be pumped to the waste liquid storage tank 22 so that the waste liquid therein is quickly discharged.
[0030]
The particle size distribution measuring apparatus in the above embodiment irradiates the flow cell 16 with laser light, and uses the light diffraction or scattering phenomenon caused by the particles in the sample liquid 10 in the flow cell 16 to measure the particle size distribution. However, the present invention is not limited to this, and the dispersion bath 2 , the flow cell 16, and the circulation device for dispersing the sample 6 in the dispersion medium 9 are configured. Any particle size distribution measuring apparatus including a measurement circulation system 19 connected to the pump 17 via a circulation flow path 18 can be similarly applied. Therefore, if the measurement circulation system 19 is provided, light is irradiated to particles that are dispersed in a dispersion medium and perform Brownian motion, and interference light generated by Doppler shift of scattered light by the particles is electrically detected. The present invention can be similarly applied to a dynamic light scattering particle size distribution measuring apparatus that converts a signal into signals and applies a suitable arithmetic process to calculate the particle size distribution.
[0031]
【The invention's effect】
As described above, according to the particle size distribution measuring apparatus of the present invention, the waste liquid such as the sample liquid and the cleaning liquid after the measurement in the measurement circulation system can be efficiently drained, and a plurality of measurements are continuously performed. In such a case, the preparation time between one measurement and the next measurement can be reduced as much as possible, and a desired measurement can be efficiently performed in a short time. Therefore, many samples can be measured efficiently in a short time.
[Brief description of the drawings]
FIG. 1 is a diagram schematically showing an example of the configuration of a particle size distribution measuring apparatus according to the present invention.
FIG. 2 is a flowchart for explaining the operation of the particle size distribution measuring apparatus.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 2 ... Dispersion bath, 6 ... Sample, 9 ... Dispersion medium, 10 ... Sample liquid, 16 ... Flow cell, 17 ... Circulation pump, 19 ... Measurement circulation system, 20 ... Open / close valve, 21 ... Drain pipe, 22 ... Waste liquid storage tank 22a ... Air vent piping, 25 ... Drainage flow path.

Claims (1)

In a particle size distribution measuring apparatus having a measurement circulation system in which a dispersion bath, a flow cell, and a circulation pump, in which a sample is dispersed in a dispersion medium, are connected via a circulation channel, circulation of the measurement circulation system A drain pipe that is thicker and shorter than the circulation channel pipe is connected to the flow path, and an open / close valve is provided on the drain pipe, and a waste liquid storage tank is connected to the downstream end of the drain pipe. The internal volume of the waste liquid storage tank is set to be larger than the sum of the total amount of the sample liquid used for one measurement and the total amount of the cleaning liquid used for cleaning the measurement circulation system after the measurement. And the particle size distribution measuring apparatus characterized by the air vent piping and the drainage flow path being connected to the said waste liquid storage tank.

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