JP2000162117A - Particle size distribution measuring device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To automatically supply a dispersing medium to the dispersion bath of a sample liquid circulation system or regulate the concentration of a sample liquid without requiring the piping work to the body casing of a particle size distribution measuring device having the sample liquid circulation system and a measuring system. SOLUTION: A body casing 4 is provided with a sample liquid circulation system 1 having a dispersion bath 11 connected to a flow cell 15 through a circulating passage 14 and a measuring system 2 for emitting laser beam to a sample liquid carried in the flow cell 15 to measure the particle size distribution of the sample on the basis of the diffracted light pattern at that time. The part at least from a feed pump 6 to an injection end part 7 of a dispersing medium supply system 3 for supplying a dispersing medium to the dispersion bath 11 is provided on a sub-casing 5 separated from the body casing 4 so as to protrude the injection end part 7 from the sub-casing 5. The injection end part 7 is opposed onto the dispersion bath 1 on the body easing side 4 in the state where the sub-casing 5 is horizontally mounted on the body casing 4 so as to oppose a prescribed side surface 4a of the body casing 4 to a prescribed side surface 5a of the sub-casing 5, and a control means provided on the body casing 4 side to control the whole device is electrically connected to the control part of the dispersing medium supply system 3 provided on the sub-casing 5 side.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a particle size distribution measuring device for measuring the particle size distribution of particles such as powder samples.

[0002]

2. Description of the Related Art Particle measurement technology covers a wide range of fields such as medicines, foods, ceramics, cosmetics, paints, and pigments.
It is indispensable in determining and evaluating the performance of powdered materials, and their importance is increasing day by day. One of the devices for measuring the particle size distribution of such particles is a laser diffraction / scattering type particle size distribution measuring device. In a sample liquid circulation system in which a dispersion bath and a flow cell are connected via a circulation channel, this particle size distribution measuring device supplies a dispersion medium to a dispersion bath and also inputs a sample, and mixes and stirs them to form a sample liquid. And irradiating the sample solution flowing in the flow cell with laser light, and measuring the particle size distribution of the sample in the sample solution based on the diffraction and / or scattered light pattern at that time. Then, the sample liquid circulation system and the measurement system are installed in one housing to form an apparatus main body.

[0003] When the particle size distribution is measured by the apparatus configured as described above, a dispersion medium must first be supplied to a dispersion bath of a sample liquid circulation system. Therefore, conventionally, it has been necessary to connect the liquid tank storing the dispersion medium and the dispersion bus of the apparatus main body with a pipe via a supply pump.

[0004]

However, in some cases, the type of the dispersion medium must be changed depending on the sample to be measured. In the configuration of the apparatus, each time the dispersion medium is changed, the type of the dispersion medium is connected to the dispersion bus until then. Must be reconnected to the new dispersion medium supply system,
There is a problem that not only the piping work is troublesome, but also the remodeling of the device main body and the like is required when the piping is re-installed.

Further, since the apparatus main body and the dispersion medium supply system are completely electrically separated from each other, the control means of the apparatus main body cannot control the dispersion medium supply system. There is also a problem that the automatic adjustment of the liquid concentration cannot be easily performed.

The present invention has been made in consideration of the above-mentioned matters, and has as its object to simply connect a sub-housing to a main-housing provided with a sample liquid circulation system and a measuring system, and to perform piping. An object of the present invention is to provide a particle size distribution measuring apparatus capable of automatically supplying a dispersion medium to a dispersion bath constituting a sample liquid circulation system and adjusting the concentration of a sample liquid without requiring any operation.

[0007]

In order to achieve the above object, a particle size distribution measuring apparatus according to the present invention comprises: a sample liquid circulation system in which a dispersion bath and a flow cell are connected via a circulation flow path; Irradiating the flowing sample liquid with laser light, and measuring a particle size distribution of the sample in the sample liquid based on a diffraction and / or scattered light pattern at that time, comprising: A circulation system and a measurement system are provided in the main body housing, and in a sub-housing separate from the main body housing, at least from a supply pump to an injection end of a dispersion medium supply system for supplying a dispersion medium to the dispersion bus. Is provided such that the injection end protrudes from the sub-housing, and the sub-housing is laid sideways on the main housing such that a predetermined side surface of the main housing and a predetermined side surface of the sub-housing face each other. On the distribution bus on the main unit housing It is characterized in that the serial injection end has to face.

In the particle size distribution measuring apparatus according to the present invention, the injection end of the dispersion medium supply system faces the dispersion bath of the sample liquid circulation system by merely placing the sub-case on the main body case, and the dispersion medium supply system Since the control unit is electrically connected to the control means on the main body casing side, the supply of the dispersion medium to the dispersion bath and the concentration adjustment of the sample liquid can be automatically performed without the need for a pipe connection operation.

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The details of the present invention will be described below with reference to the drawings. 1A and 1B are front views of a particle size distribution measuring device according to an embodiment of the present invention.
This particle size distribution measuring device comprises a dispersion bath 11 and a flow cell 1
And a sample liquid circulating system 1 which is connected to the
And a measuring system 2 for irradiating the sample liquid flowing in the flow cell 15 with laser light and measuring the particle size distribution of the sample in the sample liquid based on the diffraction and / or scattered light pattern at that time. It is of the laser diffraction scattering type, and the sample liquid circulation system 1 and the measurement system 2 are installed in one main body housing 4.

This particle size distribution measuring apparatus includes a sub-housing 5 separate from the main housing 4, and the sub-housing 5 is provided with a dispersion bath 11 for the sample liquid circulation system 1. In the dispersion medium supply system 3 for supplying the medium, a part from the supply pump 6 to the injection end 7 is installed, and the inverted L-shaped injection end 7 with the tip directed downward is a predetermined side surface 5 a of the sub-housing 5. From the outside.

The dispersion medium supply system 3 includes the supply pump 6
In addition, a dispersion medium storage tank 8 provided outside the sub-housing 5 is provided, and a suction port of the supply pump 6 is connected to the dispersion medium storage tank 8 via a hose 9. The discharge port of the supply pump 6 is connected to the injection end 7 via a solenoid valve 10.

FIG. 4 schematically shows the entire configuration of the particle size distribution measuring device. In the sample liquid circulating system 1 installed in the main body housing 4, the dispersion bath 11 is used for dispersing a powder (or slurry) as a measurement sample to be introduced and a dispersion medium (for example, pure water or alcohol) for dispersing the powder. This is a cylindrical liquid tank that mixes into a sample liquid, and is connected to a flow cell 15 via a circulation flow path 14 including a centrifugal pump 12 functioning as a circulation pump and a drainage pump and a switching valve 13. This distribution bus 11 is installed in the right half of the main body housing 4. Further, in the circulation channel 14, the distribution bus 11
The outgoing pipe 16 on the side where the sample liquid flows out from the
The centrifugal pump 12 which is connected to the bottom surface of the pump and disposed in the middle of the outward pipe 16 is driven by the motor 18.

In the circulation flow path 14, the return pipe 17 on the side where the sample liquid flows into the dispersion bath 11 has an inflow direction of the sample liquid returning to the dispersion bath 11 as shown in a horizontal cross section in FIG. Decentralized bus 11 shifted from the center of bus 11
Is connected to the peripheral wall of the distribution bus 11 so as to be directed along the peripheral wall of the distribution bus 11. The connection position is lower than the liquid level of the sample liquid in the dispersion bath 11. Thereby, the flow of the liquid flowing into the dispersion bath 11 from the circulation channel 14 is
As shown in FIG. 5, the sample liquid in the dispersion bath 11 can be stirred in a vortex shape without using a stirring blade because the sample solution is along the peripheral wall of the cylindrical dispersion bath 11.

An ultrasonic vibrator 19 oscillated by an oscillator is provided outside the bottom surface of the dispersion bath 11 so as to prevent the sample liquid from segregating in the dispersion bath 11 by its driving. I have.

A drain passage 20 is connected to the circulation passage 14 via the switching valve 13. By switching the switching valve 13, connection and disconnection between the circulation flow path 14 and the drain flow path 20 are performed. The switching valve 13
Are driven to be switched by a solenoid 21. Further, the upper position of the peripheral wall of the dispersion bath 11 and the drainage channel 20 are connected via an overflow channel 22.
When the sample liquid obtained in the dispersion bath 11 exceeds a predetermined liquid level, excess sample liquid is led out to the drain flow path 20 via the overflow flow path 22.

The dispersion bus 11 is provided with a float switch 23 for detecting that the sample liquid has dropped to a predetermined liquid level at which the sample liquid is depleted.

The measurement system 2 irradiates the flow cell 15 of the sample liquid circulation system 1 with laser light, detects the diffraction and / or scattered light at that time, and obtains the diffraction and / or scattered light obtained thereby. The laser light source 24 provided on one side of the flow cell 15 and the condensing lens provided on the other side of the flow cell 15 are used to obtain the intensity distribution of the sample and the particle size distribution of the sample based on the Fraunhofer diffraction and Mie scattering theory. 25, a photodetector 26, and a signal processing unit 27 that processes an output signal from the photodetector 26.

FIG. 3 is a plan view showing a schematic configuration inside the main body housing 4 and the sub-housing 5. In the main body housing 4, in addition to the aforementioned sample liquid circulation system 1 and measurement system 2,
A power supply 30 for these systems and a control means 31 for controlling the operation of the entire apparatus are provided. In the sub-housing 5, in addition to the supply pump 6 and the solenoid valve 10 constituting the dispersion medium supply system 3 described above, a power supply 32 and a control unit 3 are provided.
3 are provided.

Further, as shown in FIG. 2A, a sub-housing 5 is provided on one side 4a of the main housing 4 as shown in FIG.
When one side surface 5a is laid sideways so as to face each other,
An entry window 34 that allows the injection end 7 on the sub-housing 5 side to protrude into the main housing 4 and face above the distribution bus 11;
A connector 35 is provided. As shown in FIG. 2B, a connector 36 electrically connected to the connector 35 on the side of the main body housing 4 in the sideways state is provided on the side surface 5 a of the sub-housing 5. An opening 37 is formed to allow the end 20a of the drain passage 20 projecting from the side surface 4a of the body 4 to escape. By the connection of the two connectors 35 and 36, a control signal output from the control means 31 (FIG. 3) of the main housing 4 is transmitted to the control unit 33 (FIG. 3) on the sub-housing 5 side via the connectors 35 and 36. Transmitted, thereby providing the feed pump 6
And the solenoid valve 10 is controlled. Note that, instead of using the two connectors 35 and 36 as described above, an electrical connection may be appropriately made using a cable.

Next, the operation of the particle size distribution measuring device will be described. When, for example, pure water is used as the dispersion medium for the particle size distribution measurement, the sub-housing 5 connected to the dispersion medium storage tank 8 storing pure water is selected, and the sub-casing 5 is connected to the main body as shown in FIG. Put it on the housing 4 sideways. As a result, the injection end 7 of the dispersion medium supply system 3 that supplies pure water as a dispersion medium faces above the dispersion bath 11 of the sample liquid circulation system 1 installed in the main body housing 4, and in the case of the conventional example. This makes it possible to automatically supply the dispersion medium to the dispersion bath 11 and to automatically adjust the concentration of the sample liquid obtained in the dispersion bath 11 without the need for such a piping operation.

That is, when an operation start command for supplying the dispersion medium is input on the main body housing 4 side,
Signals for controlling the supply pump 6 and the electromagnetic valve 10 of the dispersion medium supply system 3 are sent to the control unit 33 on the sub-housing 5 side via the units 5 and 36, the electromagnetic valve 10 is opened, and the supply pump 6 is operated. . As a result, pure water as a dispersion medium stored in the dispersion medium storage tank 8 is injected into the dispersion bath 11 from the injection end 7.

When a predetermined amount of the dispersion medium is supplied into the dispersion bus 11 and the circulation channel 14, the supply pump 6 of the dispersion medium supply system 3 is stopped under the control of the control means 31, and the electromagnetic valve 10 is closed. The supply of the dispersion medium stops.

Thereafter, for example, a predetermined amount (several mg to several g) of the powder sample is put into the dispersion bus 11 and an operation start command of the dispersion process is input on the main body housing 4 side, so that the motor 18 is driven. Then, the centrifugal pump 12 operates and the ultrasonic vibrator 19 operates. Thereby, the circulation in which the dispersion medium mixed with the powder sample flows through the circulation channel 14 from the inside of the dispersion bath 11 and returns to the dispersion bath 11 again is repeated.

At this time, the distribution bus 11
As shown in FIG. 5, the flow of the liquid flowing into the inside follows the peripheral wall of the cylindrical dispersion bath 11, so that the liquid is stirred in the dispersion bath 11 in a vortex shape. The liquid is stirred and dispersed by the stirring action and the dispersion action of the ultrasonic vibrator 19,
Furthermore, by circulating through the circulation channel 14, a sample liquid which is uniform and free from segregation is obtained.

The concentration of the obtained sample solution is measured under the condition that the sample solution is circulated in the circulation flow path 14.
By irradiating the laser beam toward the flow cell 15 from FIG. 4 (FIG. 4), it is measured from the ratio of the irradiation light and the transmitted light at that time. When the concentration of the sample liquid is too high, the dispersion medium supply system 3 is driven again under the control of the control means 31 and the dispersion medium is further supplied into the dispersion bath 11 for dilution. Thus, the automatic concentration adjustment of the sample liquid is performed. Then, when the sample liquid flowing through the flow cell 15 has a concentration suitable for measurement, the particle size distribution measurement is performed.

After the measurement is completed, when a drain operation start command is input on the main body housing 4 side, the ultrasonic vibrator 19 and the centrifugal pump 12 are operated, and the switching valve 13 is further switched to drive the circulation passage 14. Are connected to the drain passage 20.
Thereby, the sample liquid in the dispersion bath 11 and the circulation channel 14 is drained through the drain channel 20. In addition, the operation of the ultrasonic vibrator 19 causes the powder sample attached or deposited on the peripheral surface or the bottom surface in the dispersion bath 11 to float at the time of drainage, so that the powder sample does not remain in the dispersion bath 11 efficiently. Is discharged. The operation of the ultrasonic vibrator 19 is stopped before the inside of the distribution bus 11 becomes empty in response to the detection signal of the float switch 23.

When the drainage is completed, the switching valve 13 is switched and driven to disconnect the circulation channel 14 from the drainage channel 20. In this state, the dispersion medium is supplied from the dispersion medium supply system 3 to the dispersion bath 11. Then, the centrifugal pump 12 is operated to wash the sample liquid circulation system 1. The liquid after the washing is drained in the same manner as in the previous draining operation. By repeating such a washing operation several times, the sample liquid circulation system 1 is completely washed. In addition, the drainage discharged from the drainage channel 20 is discharged through a pipe provided in the main body housing 4.

When a different dispersing medium, such as alcohol, is used as the dispersing medium, the sub-casing 5 is separated from the main casing 4 to supply another dispersing medium using alcohol as the dispersing medium. By laying the sub-housing 5 provided with the system sideways on the main housing 4 in the same manner as in the previous case, the alcohol as the dispersion medium is automatically transferred to the dispersion bath 11 on the main housing 4 without piping work. It can supply and automatically adjust the concentration of the sample solution.

[0029]

As described above, the particle size distribution measuring apparatus according to the present invention relates to a sample liquid circulation system in which a dispersion bath and a flow cell are connected via a circulation channel, and a sample liquid flowing through the flow cell. A measurement system for irradiating a laser beam and measuring a particle size distribution of the sample in the sample liquid based on a diffraction and / or scattered light pattern at that time, wherein the sample liquid circulation system and the measurement system are The dispersion medium supply system for supplying the dispersion medium to the dispersion bath is provided at a portion from the supply pump to the injection end in a sub-housing separate from the main body housing. Part is provided so as to protrude from the sub-housing, and in a state where the sub-housing is laid sideways on the main housing so that a predetermined side surface of the main housing and a predetermined side surface of the sub-housing face each other, The injection end faces the distribution bath By simply placing the sub-housing sideways on the main housing, the injection end of the dispersion medium supply system faces the dispersion bath of the sample liquid circulation system, and there is no need for piping connection work. It is possible to automatically supply the dispersion medium and adjust the concentration of the sample liquid.

[Brief description of the drawings]

FIG. 1A is a front view showing a state in which a sub-housing is separated from a main housing of a particle size distribution measuring apparatus according to an embodiment of the present invention, and FIG. It is a front view showing the state where the body was laid sideways.

FIGS. 2A and 2B are perspective views each showing a state where a sub-housing is separated from a main housing of the apparatus.

FIG. 3 is a plan view showing a configuration inside a main body housing and inside a sub-housing of the apparatus.

FIG. 4 is a diagram schematically showing a configuration of the device.

FIG. 5 is a horizontal sectional view of a distribution bus in the apparatus.

[Explanation of symbols]

1: Sample liquid circulation system, 2: Measurement system, 3: Dispersion medium supply system, 4
... Main body housing, 5 ... Sub housing, 6 ... Supply pump, 7 ... Injection end, 11 ... Dispersion bus, 14 ... Circulation flow path, 15 ... Flow cell, 31 ... Control means, 33 ... Control unit

Claims (1)

[Claims] 1. A sample liquid circulation system in which a dispersion bath and a flow cell are connected via a circulation channel, and a sample liquid flowing in the flow cell is irradiated with laser light, and diffraction and / or scattered light at that time is irradiated. A particle size distribution measuring device having a measurement system for measuring the particle size distribution of the sample in the sample liquid based on a pattern, wherein the sample liquid circulation system and the measurement system are provided in a main body housing, and are separate from the main body housing. In the sub-housing, at least a portion from the supply pump to the injection end of the dispersion medium supply system for supplying the dispersion medium to the dispersion bath is provided so that the injection end protrudes from the sub-housing, With the sub-housing laid sideways on the main housing so that the predetermined side surface of the housing and the predetermined side surface of the sub-housing face each other, the injection end faced the distribution bus on the main housing side. Particle size distribution measuring device characterized by the following: .