JP2001305040A - Sampling system for inline grain size measuring machine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a sampling system for an inline grain size measuring machine for micro-powder such as toner having a strict grain size standard for a printer or a photocopier. SOLUTION: This sampling system is provided with a rotary receiving hopper positioned inside a powder passage tube in the downstream of a powder outputting part varying its discharging quantity for storing a predetermined quantity of powder passed through the powder passage tube, a discharging screw device discharging the powder stored in the rotary receiving hopper to the outside of the powder passage tube at an optional speed, and a grain size measurement machine inputting the powder outputted from the discharging screw device and measuring its powder grain size. In this system, a time required for completely discharging the powder fully filling the rotary receiving hopper is regulated by regulating both/either of a discharging speed of the discharge screw device and a storable quantity of the rotary receiving hopper so that no powder remains substantially inside the rotary receiving hopper when the powder outputting part is switched from a low output to a high output on condition that the powder is continuously discharged from the discharging screw device.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] The present invention relates to a sampling system for an in-line particle size analyzer. More specifically,
For the purpose of manufacturing fine powders with strict standards regarding the particle size of toner and chemicals used in printers and copiers, and for the purpose of manufacturing this kind of fine powder,
It is necessary to monitor the particle size at the discharge side of machines where the discharge amount fluctuates (including intermittent and pulsating flows), such as cyclones (centrifugal separation), bub filters (dust collectors), tanks, etc. The present invention relates to a sampling system for an in-line particle size measuring device devised so as to be able to measure a more ideal particle size corresponding to an environment.

[0002]

2. Description of the Related Art When a system for measuring particle size is constructed in an in-line type in a powder processing for handling powder having a small particle size such as toner or chemicals to be processed, the sampled powder is measured. It is indispensable to perform the dispersion treatment of the powder before. Because of the necessity of such a treatment step, in order to measure the particle size with high accuracy only in the passage tube of the powder, it is necessary to create an air flow at a level enabling dispersion in the passage tube. However, this method
This will create a substantially high level of turbulence in the passage tube. Therefore, as shown by the dotted line in FIG. 1, a sampling tube is installed in the passage tube so as to penetrate the side wall of the passage tube, and the opening of the tube is positioned substantially at the center of the passage tube. In addition, this opening is an entrance having a size capable of taking in an appropriate amount of powder, and further, a negative pressure process is performed on a side opposite to the opening of the sampling tube, and the negative pressure process is performed on the opening. The powder to be sampled is sucked by the negative pressure and moves through the sampling tube. In addition, this negative pressure treatment works in common with the power provided to the measuring device while dispersing the powder that has moved through the sampling tube. In this way, the transferred powder is provided to the measuring device after being subjected to the dispersion treatment, and accurate measurement is performed.

[0003]

In such sampling, although there is a slight difference due to the difference in the shape of the sampling tube, an intermittent (pulsating) sample (pulse flow) responding to the discharge amount of an arbitrary powder processing apparatus. Sample) is obtained from the sampling tube, which is analyzed by an in-line particle sizer. Since the analysis result follows the supply of the sample, the obtained result is also intermittent. Furthermore, since it is difficult to distinguish between a measurement result error caused by a shortage of supply amount and a measurement result error caused by the particle size being smaller than the measurement limit, a user who monitors the measurement result error requires only the supply amount. The first is that it is difficult to distinguish whether the particle size is insufficient or the particle size is too small and inappropriate.
Issues existed. Furthermore, as is apparent from the figure, since the sampling tube is a simple through tube, the powder to be sampled cannot be discharged to the outside unless a negative pressure treatment is performed, and Also, the powder cannot be dispersed as a pretreatment for measurement. Therefore, as shown in the prior art, the sampling tube subjected to the negative pressure treatment disturbs the air flow in the passage tube, and the turbulence of the air flow causes the downstream (possibly upstream) machine (particularly, the air flow) to flow therethrough. A sensitive type). In addition, the machine which is sensitive to this air flow is a rotary classifier,
An air classifier is given as an example, and the difference in air flow between the case where measurement is performed by applying a negative pressure for the above sampling and the case where negative pressure processing is not performed because measurement is not performed. It must be noted that In addition, although it is possible in desk theory that the above-described dispersion processing step can be appropriately incorporated in the processing apparatus, it is possible to incorporate the measurement portion in advance in the processing apparatus. In the case of measuring the required particle size, the system of the measuring instrument itself is sensitive, and therefore, arbitrarily changing the measuring point is
As described above, changing the location to be incorporated in the processing apparatus requires rebalancing the entire system each time the location is changed. Therefore, it is difficult to incorporate a measuring instrument into the above-mentioned processing apparatus, which is made possible without performing negative pressure processing, in an actual system.

[0004]

In order to solve the above-mentioned problems, a sampling system for an in-line particle size measuring instrument as defined in claim 1 is provided in a powder passage pipe downstream of a powder output part whose discharge amount fluctuates. And a rotary receiving hopper for storing a predetermined amount of powder passing through the powder passage tube, and moving the powder stored in the rotary receiving hopper out of the powder passage tube at an arbitrary speed. It comprises a discharge screw device for outputting, and a particle size measuring device for measuring the particle size of the powder by inputting the powder output from the discharge screw device.

According to another aspect of the present invention, in addition to the features of claim 1, one or both of the discharge speed of the discharge screw device and the amount that can be accommodated in the rotary receiving hopper are adjusted. By adjusting the time required until the powder of the rotary receiving hopper one cup is completely discharged,
The powder discharged from the discharge screw device is not interrupted. Further, if desired, the above adjustment is performed such that the powder remaining in the rotary receiving hopper at the time of switching from the low output of the powder toward the rotary hopper from the powder output unit to the high output is minimized. It is preferable to adjust one or both of the amounts that can be accommodated in the rotary receiving hopper. In addition, as an example of automating this adjustment, the fluctuation of the concentration of the sample reaching the particle size analyzer is set in advance, and the automatic adjustment is performed so as to have the same fluctuation within the fluctuation of the concentration. Is mentioned.

Further, according to the present invention having another object, in addition to the features of claim 1, the powder output from the discharge screw device is input to a particle size measuring device via an air guiding device. I have.

[0007]

FIG. 1 is a schematic diagram showing an outline of a sampling system for an in-line particle size analyzer according to the present invention.

FIG. 1 shows a part of a system for manufacturing a toner used in a copying machine or a printer, and an embodiment of the present invention will be described using this system. First, the raw material 01 of the toner is introduced into a (cross) jet mill 02, and crushed or classified, and thereafter, a collection process or a fine powder removal process is performed in a cyclone 03.
While being controlled by the rotary valve 04 (the rotary valve 04 may be of a double damper type if desired), the toner treated in step 3 drops intermittently and naturally. The toner that has fallen naturally passes through the powder passage tube 05,
In addition, a part thereof enters the rotary receiving hopper 10 provided in the powder passage tube 05. The rotary receiving hopper 10
Is mounted so as to freely rotate through a side wall of the powder passage tube 05. A discharge screw 12 is provided in the rotary receiving hopper 10, and the discharge screw 12 is formed so as to protrude outward through a side wall of the powder passage tube 05. Further, the discharge screw 12 is connected to a rotation drive unit 14 capable of appropriately controlling the rotation speed. The rotary receiving hopper 10 is provided with the discharge screw 1.
The rotation can be adjusted as the same axial movement as the rotation of the rotation of the hopper 2. The amount of the toner that the hopper can receive substantially changes according to the rotation, and the hopper is used by utilizing the change. It is possible to fine-tune the amount of storage inside.

The toner sample conveyed by the discharge screw 12 moves to the output section 13 by both the action of the rotation of the discharge screw and the action of dropping. It is possible to directly attach the particle size measuring device 20 directly below the output unit 13 (whether or not the particle size measuring device can be directly attached depends on the model of the particle size measuring device).
One end of the air guiding device 15 is connected, and the other end is connected to a particle size measuring device 20 via an inlet valve 22.
The particle size measuring device 20 is a particle size distribution type measuring device that irradiates a sample with laser light, detects the state of diffraction and scattering of the light, and measures the particle size of the granular material. The sample that has passed through the particle size measuring device 20 passes through a discharge pipe 24 through an outlet valve 23,
(The sample returned from the discharge pipe 24 may disturb the air flow, and in the case of such a nervous system,
The discharge pipe 24 can be selected to discharge to a separately provided discharge unit without returning to the downstream of the powder passage pipe 05).
Reference numeral 19 denotes a sample inviting air device for sending a sample to the particle size measuring device 20. The sample inviting air device 19 is introduced near the connection of the pipe of the air guiding device 15 to the particle size measuring device 20 side. The sample attraction air device 19 attracts air,
Introducing pipe 17 in pipe 15 of air guiding device
The sample inside is moved, the sample is sent into the particle size measuring device 20, and after the particle size is measured, the sample is returned to the downstream of the powder passage tube 05 through the discharge pipe 24. Also, reference numeral 2
Reference numeral 1 denotes a purge air device which is connected to the particle size measuring device 20 to purify the inside of the device and improve the accuracy of the measurement result.

In FIG. 1, a conventional sampling method is indicated by a dotted line. That is, the opening which is one end of the air guiding device is directly installed in the powder passage tube 05 'in which the sample is conveyed by air, the sample is sampled by the suction action, and the sample is measured by the particle size measuring device 20. I was

The sampling device 11 includes a rotary receiving hopper 10, a discharge screw 12, and a rotation driving unit 14.
And an output unit 13. The basic functions are the same as those described with reference to FIG.
This will be described in detail with reference to FIG.

The sampling device is mounted on a mounting flange 06 provided on the side wall of the short powder passage tube 05 for connection. Mounting flange 06
Has a mounting portion 07, and the rotary receiving hopper 10 is rotatably received in a sealed state. In addition, the rotary receiving hopper 10 is
A hopper rotation air motor 08 connected via a rotation connection function that mechanically operates the rotation of the hopper is mounted below the mounting flange 07. The rotation of the air motor 08 causes the rotary receiving hopper 10 to move in the direction indicated by the arrow A.
Can rotate or rotate in the direction indicated by. Next, a discharge screw 12 incorporated in the rotary receiving hopper 10 is connected to a discharge case 14 forming an output portion 13.
On the opposite side of the rotation receiving hopper 10, the bearing is rotatably supported by bearings, and is connected to the screw motor 14 b via the turning point transmission mechanism 14 a, and discharges depending on the screw motor 14 b. The screw 12 is rotated. Screw motor 14b
A rotation control unit 1 for controlling the number of rotations as desired.
4c, and the rotation control unit 14c further includes:
The computer is connected to a system control computer 30 (see FIG. 1), and a control α method described later is performed by the computer (if necessary, it can be adjusted manually). In this manner, the sample received by the rotary receiving hopper 10 is transported to the discharge case 14d in an amount corresponding to the rotation speed of the discharge screw 12, and then falls naturally in the hollow of the discharge case 14d. It reaches the output unit 13. Output unit 1
3 is further connected to a suction hose joint 16. The structure of the suction hose joint portion 16 includes a ventilation hole 16b having a suction filter 16a on one side, and a hose connection portion 16c on the other side, and an opening 16d for connection with the output portion 13 at the upper center. Have been. The opening 16d is connected to the output unit 13 without a gap, and the hose connection 16c is connected to the introduction pipe 17.

FIG. 3 is a graph showing the results measured by the particle size measuring device 20. The range 50 is the measurement result in the present embodiment, and the range 60 is the conventional sampling method shown by the dotted line in FIG. It is a measurement result obtained by the above. The data with a diamond mark indicates a particle diameter of 90% passing, the data with a square mark indicates a passing particle diameter of 50%, and the data with a circular mark indicates a particle diameter of 10%.
5 shows the results of detecting the% passage particle size. The data without the mark indicates the concentration of the sample supplied to the particle size measuring device 20. Further, an area indicated by reference numeral 61 indicates an unmeasurable area. In this unmeasurable area, if the sample concentration is investigated, it is possible to grasp the fact that detection is impossible due to insufficient sample concentration, but it is necessary to take extra steps before grasping the fact. There was a problem with the increase in time and process. In addition, the unmeasurable area is a blank time during which monitoring is impossible, and the measurer (or the system operator) must monitor until the measurable area arrives, resulting in poor workability.

In the above-described embodiment, the objects to be controlled are the substantial storage capacity β associated with the rotation angle of the rotary hopper 10, the speed γ of the discharge screw, the amount of the sample introduced and the timing θ. . In the control α method, appropriate conditions for the speed γ and the storage capacity β of the discharge screw are determined while corresponding to the condition of the timing θ.
For example, a simple example is described below. First, the storage capacity β
Is the same as the amount accommodated at the inlet of the suction pipe in the conventional sampling method, and the rotation speed condition of the speed γ of the discharge screw is transported by the same amount as the sample transport amount of the air guide device 15. Under the conditions, the obtained measurement result is the same as the measurement result in the range 60. Next, when the storage capacity β is increased, the unmeasurable area 6 gradually increases.
When 1 decreases, and exceeds a certain value, as shown by the range 50, the unmeasurable region disappears, and continuous measurement becomes possible.
If the value of the storage capacity β is too large, the time lag from the timing when the sample is received by the rotary hopper 10 to the timing when the measurement is actually performed becomes too large, and a delay in particle size monitoring occurs. The most preferable condition is to set the capacity β and the speed γ of the discharge screw within a range that satisfies both the conditions for reducing the delay and eliminating the unmeasurable region. Therefore, as a control method for obtaining the control for obtaining the most preferable condition, it is possible to propose a variation width 変 動 (see FIG. 3) in advance, and set the measurement result obtained by the particle size measuring device 20 to have the above variation width ψ. Thus, the control is performed by the system control computer 30. Hereinafter, one control method for obtaining the most preferable condition will be referred to as a control α method. Also, control α
The method does not necessarily require the use of the system control computer 30. Instead, the value can be adjusted by manually adjusting the value of the storage capacity β or the speed γ of the discharge screw so that the fluctuation width approaches ψ. it can. Such a difference in control is basically related to the method of using the measurement data of the user, and when the delay time of the granularity monitoring may be large, the value of the capacity β is larger, In addition, the value of the speed γ of the discharge screw may be simply specified so as to be small enough not to generate an unmeasurable region.

Next, points to be particularly noted when using the system according to the present application are listed. -When the sample is supplied extremely irregularly, a sensor that measures the amount of sample passing is provided upstream of the rotary receiving hopper, and the storage capacity β and the discharge capacity are determined according to the timing of the supply amount and the integrated amount. The value of the screw speed γ can be controlled. -When there are a plurality of systems to be monitored, each is provided with a sampling device, and is provided so as to be selectively combined with one particle size measuring device 20. For example, monitoring can be performed in a time-division manner.

[0016]

According to the sampling system for an in-line particle size measuring device defined in claim 1, the powder passing through the powder passage pipe is positioned in the powder passage pipe downstream of the powder output section where the discharge amount fluctuates. A rotary receiving hopper for storing a predetermined amount, a discharge screw device for outputting the powder stored in the rotary receiving hopper out of the powder passage tube at an arbitrary speed, and a discharge screw device for outputting the powder from the discharge screw device. A particle size measuring device that inputs the powder to be measured and measures the particle size of the powder, so that the sample is averaged and supplied to the particle size measuring device from the state where the sample was conventionally supplied to the particle size measuring device in pieces. And, as a result, the unmeasurable time is reduced.

In the sampling system for an in-line particle size analyzer defined in claim 2, by adjusting one or both of a discharge speed of the discharge screw device and an amount that can be accommodated in the rotary receiving hopper, a rotary receiving device is provided. The amount of powder required for one hopper of the hopper is adjusted until the powder is completely discharged, and the powder discharged from the discharge screw device is not interrupted, and the powder output section is weakly output.
Since the powder remaining in the rotary receiving hopper is brought to substantially zero at the time of switching to the time of high output, the capacity to be taken into the hopper and the discharge speed of the discharge screw device are optimized. The time required for the sample to reach the particle sizer, which occurs when the volume supplied to the hopper is too large compared to the discharge amount, without interruption of the sample supply to the particle sizer. The problem of being too long and increasing the time lag until measurement is solved.

In the sampling system for an in-line particle size measuring device defined in claim 3, the powder output from the discharge screw device is input to the particle size measuring device via an air guiding device. Need not be incorporated in the system, and the airflow in the system can be stabilized. That is, as one of the techniques for closing the processing apparatus and the outside air, the possibility of incorporating the measurement portion into the powder processing system is possible under the condition that the above-mentioned dispersion processing step is well incorporated. It is on the street.
However, the particle size measurement of the powder is not always performed at the same place, and at any place of the powder processing system,
It is desired to change the measurement location relatively easily and monitor the particle size of the powder from various viewpoints. Further, in the case where such delicate monitoring is required, that is, in the case where the object to be used is a particle size measurement requiring high accuracy such as for a toner or a chemical, the system of the measuring device itself is sensitive. Changing the measurement location requires rebalancing of the entire system each time the measurement is changed. Therefore, incorporating a measuring instrument in the processing device
I would like to avoid it as much as possible because it may cause a loss of balance. One solution that satisfies such strict requirements is the configuration shown in claim 3. In other words, since the air guiding device is used after the output from the discharge screw device without directly forming a negative pressure in the processing device, the airflow in the processing device is not disturbed, and accurate particle size measurement is performed. After performing the dispersion treatment of the powder for performing the measurement, the measurement can be performed by the particle size measuring device, so that the measurement result is more accurate than the case where the dispersion treatment is not performed.

[Brief description of the drawings]

FIG. 1 is a schematic diagram showing an entire system of a powder processing apparatus.

FIG. 2 is a detailed view of a sampling device, in which (A) is a side view for explanation drawn from the rotation drive unit side, and the rotation drive unit is partially omitted for explanation. (B) is a partial sectional view showing a section other than the rotation drive section.

FIG. 3 is a graph showing a result measured by a particle size analyzer.

[Explanation of symbols]

 Reference Signs List 01 Raw material of toner 02 Cross jet mill 03 Cyclone 04 Rotary valve 05 Powder passage tube 10 Rotary receiving hopper 12 Discharge screw 13 Output unit 14 Rotary drive unit 15 Air guiding device 19 Sample inviting air device 20 Particle size analyzer 22 Inlet Valve 23 Outlet valve 24 Discharge pipe

Claims (3)

[Claims] 1. A rotary receiving hopper positioned in a powder passage pipe downstream of a powder output section whose discharge amount fluctuates and containing a predetermined amount of powder passing through the powder passage pipe; A discharge screw device for outputting the powder stored in the receiving hopper at an arbitrary speed to the outside of the powder passage tube, and a particle size for inputting the powder output from the discharge screw device and measuring the particle size of the powder A sampling system for an in-line particle size analyzer, comprising a measuring device. 2. Adjusting one or both of the discharge speed of the discharge screw device and the amount that can be accommodated in the rotary receiving hopper, the powder required for one full rotation of the rotary receiving hopper is discharged. 2. The sampling system for an in-line particle size measuring device according to claim 1, wherein the time for performing is adjusted so that the powder discharged from the discharge screw device is not interrupted. 3. The sampling system according to claim 1, wherein the powder output from the discharge screw device is input to a particle size measuring device via an air guiding device.