JP3307082B2 - Particle size distribution analyzer - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an on-line particle size distribution measuring apparatus utilizing laser diffraction light scattering, and more particularly to an on-line apparatus equipped with a diluting / stirring apparatus used in the field of producing coal ash, cement and the like. And a particle size distribution measuring device.

[0002]

2. Description of the Related Art In general, in an on-line particle size distribution measuring apparatus shown in FIG. 4, a powder sample is charged from a branch pipe 34 of a sample charging pipe 33 into water put in a stirring tank 32 of a dilution stirring apparatus 31.
The solution well stirred by the stirring blade 35 is sent to the flow cell 37 of the particle size distribution measuring unit 36 by the pump unit 6 and the laser light is transmitted to measure the particle size distribution. In this case, the flow cell 3
The solution that has passed through 7 is returned to the stirring tank 32 and circulated again. The stirring drive of the stirring tank 32, the circulating water supply by the pump 6 to the flow cell 37 and the operation of charging the sample are performed by the control unit (CPU) 38, and the data measured by the particle size distribution measuring unit 36 is sent to the personal computer 39. Input and analyzed.

FIG. 3A is a detailed view of a conventional dilution and stirring device 31. An air knocker 40 is provided in the sample introduction pipe 33 into which the powder sample is introduced to prevent the sample from adhering and blocking. A stirring blade 35 for stirring the solution in the stirring tank 32 is attached to a shaft 42 driven by a motor 41. The shaft 42 has an impeller 18 of the pump 6 for feeding the solution to the flow cell 37. Is mounted and is driven to rotate simultaneously with stirring. FIG. 3 (B) is FIG. 3 (A)
FIG. A liquid level sensor 43 is provided in the stirring tank 32, and the amount of water is kept constant while automatically adjusting the valve 11 for tap water and the valve 21 for drainage. The suspension having passed through the flow cell 37 of the particle size distribution measuring section 36 by the pump 6 is returned to the stirring tank 32 and circulated. Reference numeral 44 denotes an ultrasonic vibrator for preventing the sample from sticking to an inner wall, an impeller, or the like.

[0004]

In the above-mentioned conventional diluting and stirring apparatus 31, when a large amount of sample is injected at once from the branch pipe 34 of the sample input pipe 33, the surface attraction of the powder sample becomes large and the penetration becomes slow. Stirring tank 3 with powder sample in block
2 is settled at the bottom of the pump 2 and fixed to the impeller 18 of the pump 6, which makes it difficult to perform uniform dilution and stirring. Further, the high concentration liquid (slurry) on the bottom surface of the stirring tank 32 has a problem that the ball valve seal is broken and the measurement flow cell 37 is extremely contaminated, so that long-term measurement cannot be performed. The present invention has been made in view of the above problems, and prevents a charged powder sample from blocking during the stirring to easily obtain a uniform suspension. An object of the present invention is to provide a particle size distribution measuring device capable of measurement.

[0005]

That is, in order to solve the above-mentioned problems, the present invention provides a method for measuring the particle size distribution of a sample suspension by circulating a pump between a dilution stirring device and a measuring section. In the particle size distribution measuring device, the dilution stirring device, a stirring tank, a sample introduction pipe, a stirrer in which an elongated space is formed in the interior and communicates with the sample introduction pipe, and a number of small holes are formed in the side wall. And a rotation mechanism for rotating the sample introduction tube, and a sample introduction unit and a circulation tube for returning the sample suspension from the tap water supply line or the particle size distribution measurement unit to the sample introduction tube. At least one of the roads is arranged.

[0006]

When the particle size distribution measuring device is the above-mentioned means, when the sample introduction tube is rotated by a drive mechanism at the time of sample introduction, the introduced sample dissolves in water inside the stirrer and the small hole of the stirrer. It is more dispersed in the stirring tank. In this case, the powder sample in the stirrer is dispersed into the stirring tank in a well-stirred state by the sample suspension circulating from the upper portion of the sample introduction pipe (see FIG. 1).

[0007]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1A is a cross-sectional view of a dilution stirrer 1 used in the particle size distribution measuring device of the present invention. The dilution stirring apparatus 1 includes a stirring tank 2, a sample introduction pipe 3, a motor 4 for rotating the sample introduction pipe 3, a pump 6, and a scraping wire 8. A lid 7 is placed on the upper part of the sample input tube 3. The lid 7 is provided with a sample input section (input branch pipe 9), a motor 10 for rotationally driving the scraping wire 8, and a valve 11. The installed tap water supply line 12 and the sample suspension circulation line 13 for returning the suspension from the particle size distribution measurement flow cell 37 (see FIG. 3) are provided (these lines). 12 and 13 may be merged into one pipe as shown in the figure). The sample input tube 3 is connected to an air knocker 4.
Vibration is given at 0. Further, a pulley 14 is provided in the sample input tube 3 and is driven by a belt.
The sample input tube 3 may be another rotation driving mechanism.

A stirrer 5 to be described later is provided below the sample introduction pipe 3, and a shaft 15 is fixed below the stirrer 5, and an impeller of a pump 6 is attached to a tip end of the shaft 15. 1
8 is attached. By driving the pump 6, the sample suspension is sent to the flow cell 37 (see FIG. 3) of the particle size distribution measuring unit 36 from the pipe 20 in which the valve 19 is disposed, and the pipe in which the valve 21 is disposed. From 22, the suspension is drained. Further, a liquid level sensor 43 is provided in the stirring tank 2 and the valves 11 and 21 are controlled so that a predetermined amount of water is filled.

A lid 7 installed on the upper part of the sample input tube 3
The scraping wire 8 attached to the motor is driven to rotate by the motor 10 to stir the input sample well in the input tube 3 to prevent the sample from blocking or adhering to the inner wall of the tube. I do. Since the sample input tube 3 itself is driven to rotate by the motor 4, the scraping wire 8 is connected to the motor 10.
This serves to stir the inside of the sample introduction tube 3 even if it is not driven.

Next, the stirrer 5 provided at the lower part of the sample introduction tube 3 is a view taken along the line XX of FIG.
As shown in (B), an elongated space 5a communicating with the sample inlet tube 3 is formed inside, and a number of small holes 5d are formed in the side walls 5b and 5c. That is, when the sample input tube 3 is driven to rotate by the motor 4, the input sample is dissolved in water inside the stirrer 5 and dispersed into the stirring tank 2 through the small holes 5d and 5d of the stirrer 5. go. In this case, the powder sample in the stirrer 5 is dispersed into the stirring tank 2 in a well-stirred state by the sample suspension circulating from the upper part of the sample introduction pipe 3.

The diluting / stirring apparatus 1 of this particle size distribution measuring apparatus has the above-described configuration, and is a diluting / stirring apparatus 3 shown in FIG.
It is installed in place of 1, but operates as follows. (1) The stirring tank 2 of the dilution stirrer 1 is filled with a predetermined amount of tap water and put on standby. (2) The motor for driving the scraping wire 8, the air knocker 40, the motor 4 for rotating and driving the sample injection tube 3, the pump 6, etc. are operated by the input signal of the operator online to input the sample. A sample collected from the line through the branch pipe 9 is supplied. (3) The introduced sample is mixed with the scraping wire 8 inside the sample introduction tube 3 and the suspension circulating from the circulation line 20, and dispersed into the stirring tank 2 through the small holes 5 d of the stirring device 5. You. (4) When the sample has been charged, the air knocker 40 stops,
The ultrasonic vibrator 23 installed at the lower part of the stirring tank 2 operates for a specified time (in this case, the scraping wire 8 and the sample introduction pipe 3).
Is rotationally driven). (5) The concentration of the sample suspension driven by the pump unit 6 of the stirring tank 2 is checked in the flow cell 37 of the particle size distribution measuring unit 36 shown in FIG. While adjusting the valve 11 and the sample discharge valve 21, automatic adjustment is performed so as to be within a specified concentration range. (6) After measuring the sample suspension having the specified concentration with the flow cell 37, the sample injection pipe 3, the stirrer 5, the stirring tank 2, etc. are washed with tap water and the drain pipe 22, and the water is washed. The washing is repeated while checking with the flow cell 37 until the cleanliness of the sample is within the permissible range of measurement. (7) When the inside of the stirring tank 2 is within the measurement allowable range, the specified amount of water is filled and the apparatus stands by for the next particle size distribution measurement.

FIG. 2 shows a modified embodiment of the dilution stirring device used in the particle size distribution measuring device of the present invention. That is, FIG.
A shaft 42 having a rotating blade 35 for stirring is provided in a stirring tank 32 shown in (A), and tap water and a sample suspension from a flow cell 37 are circulated, and the sample suspension tube 33 into which a powder sample is charged is provided. The scraping wire 8 is provided vertically, and the scraping wire 8 is driven by the motor 10 when a sample is loaded. With such a configuration, the suspension in the stirring tank 32 is stirred by the stirring blade 35 while the powder sample is injected from the branch pipe 34 of the sample injection pipe 33, and the scraping wire 8 is rotated. Of the sample and blocking of the sample during stirring can be prevented.

[0013]

According to the particle size distribution measuring apparatus of the present invention, the powder sample is not blocked in the stirring tank 2 and settles at the bottom of the stirring tank 2 because it has the configuration as described in detail above. It hardly adheres to the impeller 18 or the like.
Further, the durability of the valve seal is improved and the contamination of the measurement flow cell is reduced, so that long-term measurement can be performed.

[Brief description of the drawings]

FIG. 1A is a cross-sectional view of a dilution stirrer used in the particle size distribution measuring apparatus of the present invention, and FIG.
It is an XX arrow line view of (A).

FIG. 2 is a view showing a modified embodiment of a dilution stirring device used in the particle size distribution measuring device of the present invention.

FIG. 3 (A) is a detailed sectional view of a conventional dilution and stirring device, and FIG. 3 (B) is a view taken along the line YY of FIG. 3 (A).

FIG. 4 is a diagram showing a schematic configuration of an online particle size distribution measuring device.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 Dilution stirrer 2 Stirring tank 3 Sample supply pipe 5 Stirrer 6 Pump 7 Lid 8 Scraping wire 9 Sample supply branch pipe 11 Valve 12 Tap water supply pipe 13 Suspension circulation pipe 15 Shaft 18 Impeller 19, 21 Valve 36 Particle size distribution measuring unit 37 Flow cell

Claims (1)

(57) [Claims] 1. A particle size distribution measuring device in which a particle suspension is circulated between a dilution stirring device and a measuring section by a pump to measure a particle size distribution of a sample suspension.
A stirring tank, a sample input tube, a stirrer having an elongated space formed therein communicating with the sample input tube and having a number of small holes formed in the side wall, and a rotation driving mechanism for the sample input tube. In addition, the sample introduction pipe is provided with a sample introduction section and at least one of a circulation pipe for returning the sample suspension from the tap water supply pipe or the particle size distribution measurement section. Distribution measuring device.