JPH1010033A - Sensor head for photographing granulated body, and grain size measuring device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To precisely measure grain size by emitting a light to a powder body passing a detecting space for passing the powder body, receiving the light by a light receiving means, and photographing the granulated powder body. SOLUTION: A detecting space 20 is formed in the lower surface center of a sensor head so as to be recessed from the lower surface 12a to the upper part. Since particles of a powder A are present in the dispersed state near the surface of the powder A according to stirring in granulation, the powder A dispersedly present near the surface is penetrated into the space 20. A lens 21 and a screen 22 are arranged opposite to each other so as to both the surfaces of the space 20 within the sensor head. A light source 23 is arranged in the rear of the lens 21. A mirror 26 inserted to the lower inner part of an arm member 11 is arranged on the back part of the screen 22, and the shadow image projected on the screen 22 is reflected by the mirror 26, and then incident on a bore scope 27. The shadow image projected on the screen 22 is photographed by a CCD camera.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to granulation and coating of pharmaceuticals such as fine granules, granules and tablets, foods such as seasonings, powder metallurgy, and chemical products such as ceramic materials. The present invention relates to a photographing sensor head suitable for measuring the particle size of a granulated product in a granulating device, and a particle size measuring device for a granulated product using the sensor head.

[0002]

2. Description of the Related Art Stirring granulators, tumbling granulators, centrifugal fluidized granulators, fluidized bed granulators and the like are known as granulators for performing granulation and coating. In these granulators, accurate operation control is required in order to obtain granules having an intended particle size. Conventionally and most commonly, this operation control method employs time control for terminating granulation at a predetermined time.

However, this time control makes it difficult to keep the particle size of the granulated product accurately and constant. Therefore, recently, a method of measuring the particle size by photographing and image-processing a powder to be granulated into a granulated product in a granulator has been adopted.

[0004]

However, for example, a method of observing the inside of the granulation apparatus from the outside by opening a viewing window on the side of the granulation apparatus is usually a method in which the side of the granulation apparatus is heated for controlling temperature. Since it is configured to be covered with a jacket or the like through which the medium flows, it is difficult to provide such a viewing window. Further, when a camera for photographing is installed inside the granulating apparatus, the photographing position becomes a problem. In other words, if an image is taken at a position where it is buried deep in the raw material powder supplied to the granulator, the image taken by the camera will be full of one-sided granules and powder, The particle size of each powder cannot be measured. On the other hand, if the photograph is taken at an excessively high position in the granulating apparatus, the essential powder cannot be photographed. In order to suitably measure the particle size of the powder to be granulated into the granulated product, it is preferable to maintain the photographing position of the camera near the surface of the powder in the granulator, Height fluctuates and cannot be kept constant.

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned circumstances, and has as its object to provide a means for appropriately photographing powders dispersed and present in the vicinity of a surface and accurately measuring the particle diameter thereof. Is to provide.

[0006]

According to the first aspect of the present invention, there is provided a sensor head for photographing a powder to be granulated into a granulated material by a granulating apparatus, comprising: a detection space through which the powder passes; Light emitting means for emitting light to the powder passing through the detection space; and light receiving means for receiving light emitted from the light emitting means.

According to the particle size measuring device of the present invention, the light is projected on the powder passing through the detection space and the light is received by the light receiving means, whereby the powder is granulated. Powder can be photographed. In addition, the light receiving means is provided in claim 2
As described in (1), a structure may be provided that includes a screen that projects a shadow image created by blocking the light emitted by the light emitting means with powder. Further, the detection space is, as described in claim 3,
The sensor head may be configured to be recessed upward from the lower surface. Further, as described in claim 4, a configuration may be provided in which a nozzle for ejecting air for dispersing the powder is provided. Furthermore, as described in claim 5, the light projecting means may be configured to include a lens that converts light emitted from the light source into parallel light.

According to a sixth aspect of the present invention, there is provided an apparatus for measuring the particle diameter by photographing a powder to be granulated into a granulated material by a granulating apparatus and processing the image by image processing. An arm member freely suspended, a sensor head for photographing granulated matter according to any one of claims 1 to 5 attached to a lower end of the arm member, and a powder photographed by the sensor head. It is characterized by having an image processing device for measuring the particle size by performing image processing.

Generally, in a granulating apparatus for agitating and granulating raw material powder, powder particles are present in a dispersed state near the surface of the powder with stirring. According to the particle size measuring device of the sixth aspect, since the sensor head is attached to the lower end of the arm member suspended to be swingable, the arm member is in a state of hanging down in the granulator by its own weight, The state where the sensor head is constantly pressed with an appropriate pressure to the vicinity of the surface of the powder granulated by the granulator can be maintained. By using the light projecting means and the light receiving means provided on the sensor head, it is possible to accurately measure the particle size of the powder present in a dispersed state near the surface of the powder during operation of the granulating apparatus. It becomes possible.

In a sixth aspect of the present invention, the upper end of the arm member is swingably mounted on the upper surface of the granulating apparatus. it can. Also, as described in claim 8,
The granulating device is, for example, a stirring granulator, a rolling granulator,
It is a centrifugal fluidized-bed granulator or a fluidized-bed granulator. Also,
According to a ninth aspect of the present invention, the image processing apparatus may be configured to calculate an average particle diameter of the granulated material using a volume basis or a number basis.

[0011]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Preferred embodiments of the present invention will be described below with reference to the drawings. It is to be noted that a granulation apparatus called a Henschel mixer type (super mixer), which is one of the most traditional batch type stirring granulation apparatuses, will be described as an example.

FIG. 1 is an explanatory diagram of a granulation device 1 of the Henschel mixer type. The granulating apparatus 1 includes a cylindrical container 2, and a stirring blade 3 is disposed at the bottom of the container 2. The stirring blade 3 is driven by the electric motor 4 to drive the belt 5.
And is driven to rotate. The shape and number of the stirring blades 3 are appropriately selected depending on the purpose, but usually, the stirring blades 3 include upper and lower two-stage blades. The upper surface 6 of the container 2 is configured to be openable and closable, and a jacket 7 for temperature control is mounted around the container 2.

In the granulating apparatus 1, the powder A, which is a raw material of medicines and foods, is put into the container 2 which is opened by lifting the upper surface 6, and the agitating blade 3 is rotated by the operation of the electric motor 4 to granulate. To produce granules. When a liquid binder is used, the operation of the electric motor 4 is controlled so that the outer peripheral speed of the stirring blade 3 is, for example, about 5 to 10 m / s. On the other hand, PVC
As in the case of a compound, when the temperature is raised by frictional heat generated by the rotation of the stirring blade 3 to produce granules,
The outer peripheral speed of the stirring blade 3 is, for example, about 20 to 30 m / s,
In some cases, the electric motor 4 is set to about 40 m / s.
Control the operation of In addition, by controlling the temperature of the heat medium flowing through the jacket 7 attached to the container 2, it is possible to perform steps such as reducing the heating time when performing granulation and performing cooling after granulation. . Further, a deflector (not shown), which is a kind of baffle plate, is disposed in the container 2 to enhance the mixing efficiency, and a wiper (not shown) for scraping off the raw material when the raw material adheres to the inner wall of the container 2. )
May be provided. The amount of powder A charged into the container 2 is
Generally, the effective capacity is 2/3 of the total capacity. However, depending on the situation, more powder A may be charged into the container 2, and conversely, only a small amount of powder A may be charged.

Above the granulator 1 constructed as described above, the granule particle size measuring device 10 according to the embodiment of the present invention is mounted. This particle size measuring device 10
An arm member 11 is swingably suspended from the upper surface 6 of the container 2, and a sensor head 12 is attached to a lower end of the arm member 11.

2 and 3, the particle size measuring device 10
More specifically, in the illustrated embodiment, the arm member 11 is formed of a hollow cylindrical tube made of stainless steel, and the base 15 formed at the upper end of the arm member 11 is formed of the container 2 of the granulator 1. Bracket 16 attached to upper surface 6
Are rotatably supported by a support shaft 17 projecting therefrom. Thereby, the arm member 11 is suspended swingably with respect to the upper surface 6 of the container 2 and is in a state of hanging down by its own weight. As will be described later, a CCD camera 18 for taking a shadow image of the powder A to be granulated into granules in the container 2 of the granulator 1 is mounted on the upper surface of the base 15. Although not shown, the height at which the arm member 11 is suspended can be adjusted by changing the height of the support shaft 17.

Since the arm member 11 is swingably suspended with respect to the upper surface 6 of the container 2 in this manner, the sensor head 12 attached to the lower end of the arm member 11 can Of the powder A to be granulated / manufactured in the container 2 at a suitable pressure. That is, the arm member 11 indicated by a solid line in FIG.
The height of the surface of the arm member 1 is low.
1 hangs down by its own weight, and the sensor head 12 moves downward. On the other hand, the arm member 1 shown by a dashed line in FIG.
1 'is a case where the height of the surface of the powder A is high. At this time, the arm member 11 is pushed up by the surface of the powder A, the sensor head 12 moves upward, and is indicated by a dashed line 12'. State. As described above, the arm member 11 swings in accordance with the change in the height of the surface of the powder A, so that the sensor head 12 is constantly pressed against the vicinity of the surface of the powder A with an appropriate pressure.

As shown in FIG. 4, a detection space 20 is formed at the center of the lower surface of the sensor head 12 so as to be recessed upward from the lower surface 12a of the sensor head 12. When the granulation is performed by rotating the stirring blade 3 in the granulating apparatus 1, the particles of the powder A are present in a dispersed state near the surface of the powder A with the stirring. As described above, since the sensor head 12 is located near the surface of the powder A, the powder A
Enters the detection space 20.

The lens 21 and the screen 22 are disposed inside the sensor head 12 so as to sandwich both sides of the detection space 20 formed at the center of the lower surface of the sensor head 12 as described above. . A light source 2 made of, for example, an LED (light emitting diode) is
3 are arranged. A lead wire 24 is connected to the light source 23. The lead wire 24 passes through the inside of the arm member 11 formed of a stainless steel cylindrical tube as described above, and relays the base 15 at the upper end of the arm member 11; It is connected to a power supply 25 shown in FIG. By supplying a current from the power supply 25 via the lead wire 24, the light source 23 can emit light. The light emitted from the light source 23 is polarized when passing through the lens 21, becomes parallel light, and is received by the screen 22. When the powder A is present in the detection space 20, a shadow image created by blocking the parallel light projected through the lens 21 with the powder A is displayed on the screen 22.

On the other hand, at the back of the screen 22, there is arranged a mirror 26 placed inside the lower part of the arm member 11, and the shadow image projected on the screen 22 as described above is reflected by this mirror 26. Thereafter, light enters a borescope 27 (or an optical fiber) disposed inside the arm member 11. The borescope 27 passes through the inside of the arm member 11 and
1 is connected to a CCD camera 18 mounted on the base 15 at the upper end. Thereby, the shadow image projected on the screen 22 can be photographed by the CCD camera 18. Thus C
The shadow image projected by the CD camera 18 is transmitted to the image processing device 29 via the cable 28 shown in FIG. 3, and the particle size of the powder A is measured. The image processing device 29 is a CCD
It has a function of measuring the particle size of the powder A by performing image processing on a shadow image of the powder A photographed by a camera, analyzing the particle size distribution and the like, and analyzing the shape of an ellipse, a circle, and the like. An observation monitor for enlarging the photographed powder A at an appropriate magnification is also provided. In this case, the image processing device 29 is configured to represent the particle diameter of the powder A by the average particle diameter of the powder A calculated using the volume reference or the number reference.

2 and 3, in this embodiment, a nozzle 30 having a “J” shape is disposed on the side of the sensor head 12. The tip (lower end) of the nozzle 30 is provided. Is directed to the detection space 20 at the center of the lower surface of the sensor head 12 described above, while a pipe 32 for supplying air from an air supply source 31 is provided at the upper end of the nozzle 30 as shown in FIG. Are connected, and the air supply source 31
Is operated so that an air flow can be introduced from the tip of the nozzle 30 toward the detection space 20.

When the granulation is performed in the granulating apparatus 1 as described above, the powder A, which is a raw material of medicines and foods, is put into the container 2 which is opened by lifting the upper surface 6 and the electric motor 4
In operation, the stirring blade 3 is rotated to perform granulation to produce a granulated product. The particle size of the powder A thus granulated is measured using the particle size measuring device 10. In this case, since the sensor head 12 is always located near the surface of the powder A due to the swing of the arm member 11, the stirring space (or the nozzle 3
The powder A, which is present in a dispersed state in the vicinity of the surface (due to the air flow due to zero), enters in the form of particles.

When measuring the particle size of the powder A, a current is supplied from a power supply 25 to cause the light source 23 to emit light, and the parallel light polarized by the lens 21 is converted to the detection space 2.
The light is projected toward the powder A that has entered the inside of 0. Thus, a shadow image created by being blocked by the powder A entering the detection space 20 is projected on the screen 22. The shadow image projected on the screen 22 in this manner is reflected by the mirror 26, enters the borescope 27, and is photographed by the CCD camera 18.

The shadow image projected by the CCD camera 18 is transmitted to an image processing device 29 via a cable 28. The image processing device 29 performs image processing on the shadow image of the powder A thus obtained, and measures the particle size. The image processing device 29 also analyzes the particle size distribution and the like of the powder A, and further performs shape analysis and the like. The particle size of the powder A is represented by an average particle size of the powder A calculated using a volume basis or a number basis.
It is also possible to enlarge the appearance of the powder A captured by the CCD camera 18 on the monitor at an appropriate magnification.

Thus, according to the particle size measuring apparatus 10 of the present embodiment, the position of the sensor head 12 can be always maintained near the surface of the powder A manufactured in the container 2 of the granulating apparatus 1. Thus, the powder A can be suitably photographed in a state of being dispersed in the detection space 20, and its particle size and particle size distribution can be accurately measured.

When the powder A produced in the container 2 of the granulator 1 is relatively heavy or when the raw material powder contains an oily component, the T powder A May not be easily dispersed. In such cases,
It is preferable that the air supply source 31 is operated to introduce an air flow from the tip of the nozzle 30 arranged on the side of the sensor head 12 toward the detection space 20. By introducing the air flow, the powder A in the vicinity of the surface is soared up, and if the powder A is photographed by being introduced into the detection space 20 in a dispersed state, the particle size can be measured in the same manner as described above. Become. In the illustrated embodiment, the case of blowing upward with the “J” -shaped nozzle 30 has been described. However, the powder A may be dispersed by injecting airflow downward toward the surface of the powder A. The flow rate of the air flow supplied from the air supply source 31 is controlled by a regulator. However, the air flow is increased with the progress of the granulation so that the powder A, which gradually becomes heavier with the progress of the granulation, can be suspended. May be configured to increase the flow rate.

FIG. 5 shows a sensor head 40 according to another embodiment of the present invention. This sensor head 40 is also attached to the lower end of the arm member 11 slidably suspended in the container 2 of the granulating apparatus 1 similarly to the sensor head 12 described above with reference to FIG. Is always located near the surface of the powder A to be granulated in the container 2 of the granulator 1.

The sensor head 40 has a left and right sensor head case 41 and a right sensor head case 42, which are divided into right and left parts. By moving them closer to or away from each other, the volume of the detection space 45 at the center of the lower surface of the sensor head 40 can be reduced or expanded. In addition, gaps 48 and 49 are formed on the inner surface side of the lens 46 and the inner surface side of the screen 47 which are disposed so as to sandwich both sides of the detection space 45. The air introduced into the sensor head 40 through the pipe 50 connected to the upper surface can be ejected from the gaps 48 and 49 into the detection space 45.

The other structure of the sensor head 40 is as follows.
Since the configuration is almost the same as that of the sensor head 12 described above with reference to FIG. 4, the same components as those described with reference to FIG. 4 are denoted by the same reference numerals as those in FIG. 4, and detailed description thereof will be omitted.

Now, in the sensor head 40,
By sliding the sensor head left case 41 and the sensor head right case 42 with the slide portion 43 to change the volume of the detection space 45, the amount of the powder A entering the detection space 45 can be adjusted. Therefore, for example, when the powder A is light and easy to disperse and there is a large amount of powder A entering the detection space 45, the sensor head left case 41 and the sensor head right case 42 are moved closer to each other, and the detection space 45 is moved. May be reduced. Conversely, for example, when the powder A is heavy and hard to float and the amount of the powder A entering the exit space 45 is small, the sensor head left case 41 and the sensor head right case 42 are moved away from each other, and the detection space is What is necessary is just to expand the capacity of 45. Further, since the sensor head 40 can eject air along the inner surfaces of the lens 46 and the screen 47, the lens 4
There is an advantage that the raw material powder A or the granulated substance does not adhere to the inner surface of the screen 6 or the screen 47 and does not disturb the photographing.

[0030]

EXAMPLE The particle size of the powder was actually measured using the particle size measuring apparatus of the present invention. FIG. 6 shows the result. Since the particle size of the powder is not constant and varies in size, an image obtained by a particle size measuring device is analyzed, and a 50% average particle size obtained on a volume basis and a 50% average particle obtained on a number basis are analyzed. The particle sizes are shown. In addition, the 50% average particle size determined by the sieving method is also shown. In addition, the method obtained by this sieving method is also called a mass standard. If the density of the powder is constant, mass is obtained by multiplying the volume of the powder particles by the density, so that the volume standard and the mass standard coincide. However, since the density of the powder actually varies depending on the granulation time and the particle size, they both show the same tendency but do not completely match. In this example, the density of the powder was assumed to be 1 g / cm ^3, and the tendency on a mass basis was determined on a volume basis.

Here, the volume basis is a particle size distribution in which the frequency of each particle size of powder is represented by volume, and the number basis is a particle size distribution in which the frequency of each particle size of powder is represented by number. Distribution. The sieving method is a method in which a powder taken out as a sample from a granulator is classified using a sieve, and the particle size distribution is examined. It is considered that the particle size distribution measured by this sieving method is closest to the true value. The sieving method is a method that has been conventionally performed as described in the Japanese Pharmacopoeia. 50
The% average particle diameter is a particle diameter at which the amount of powder particles having a particle diameter larger than the particle diameter becomes 50% of the whole powder.

As can be seen from FIG. 6, according to the sieving method, the particle size of the powder gradually increases during the granulation time of 0 to about 8 minutes. You can see that it is progressing. On the other hand, after about 8 minutes, the particle size of the powder has not changed much. It is considered that the granulation was completed when about 8 minutes had elapsed.

Also, the 50% average particle size determined on a volume basis has almost the same tendency as the 50% average particle size determined by the sieving method, and it is understood that the granulation is completed when about 8 minutes have passed. Suggested. On the other hand, the 50% average particle size obtained on a number basis does not show a very large change over the whole. From this result, it is considered that the volume standard has a very good correlation with the sieving method considered to be a true value, and thus can be suitably used for the process control of the granulator. In the pharmaceutical industry, numerical values are conventionally often handled on a mass basis, but since weight and volume are in a proportional relationship, the volume basis is consistent with the custom. On the other hand, the number reference has little change and is hard to judge. The reason is that the number of particles is overwhelmingly larger than the smaller one, and when the number is based on the particle size, it tends to be pulled toward the smaller one, and the average particle size does not change much numerically. It is thought to be. However, the disadvantage of the volume standard is that if there is one very large particle, the average particle diameter becomes a large value because the particle diameter is cubed, and even if there are many small particles, it will be ignored. is there. In order to solve this drawback, for example, a threshold may be determined experimentally, and particles larger than a certain size may be ignored.

[0034]

According to the present invention, the particles of a powder that are present in a suspended state in a dispersed state in the vicinity of the surface of the powder with the agitation of the granulator can be photographed. It is possible to accurately grasp the temporal change of the diameter.

[Brief description of the drawings]

FIG. 1 is an overall view of a granulating apparatus.

FIG. 2 is an enlarged perspective view of a particle size measuring device.

FIG. 3 is a front view of the particle size measuring device.

FIG. 4 is an enlarged longitudinal sectional view of a sensor head.

FIG. 5 is an enlarged longitudinal sectional view of a sensor head according to another embodiment.

FIG. 6 is a graph showing measurement results of the example.

[Explanation of symbols]

 Reference Signs List A powder 1 granulator 6 upper surface 10 particle size measuring device 11 arm member 12 sensor head 20 detection space 21 lens 22 screen 23 light source 30 nozzle

Claims (9)

[Claims] 1. A sensor head for photographing a powder to be granulated into a granulated material by a granulating device, comprising: a detection space through which the powder passes; and a light passing through the powder passing through the detection space. And a light receiving means for receiving the light emitted from the light emitting means. 2. The granulated object according to claim 1, wherein the light receiving means includes a screen for projecting a shadow image created by blocking light emitted by the light emitting means with powder. Sensor head for photography. 3. The sensor head according to claim 1, wherein the detection space is formed so as to be recessed upward from a lower surface of the sensor head. 4. The sensor head according to claim 1, further comprising a nozzle for ejecting air for dispersing the powder. 5. The sensor head according to claim 1, wherein the light projecting unit includes a lens that converts light emitted from the light source into parallel light. 6. An apparatus for measuring the particle diameter by photographing a powder to be granulated into a granulated product by a granulator and performing image processing, wherein the apparatus is swingably suspended in the granulator. 6. An arm member, said arm member being attached to a lower end of said arm member.
And a sensor head for photographing the granulated material according to any one of the above, and an image processing device for measuring the particle size by image-processing the powder photographed by the sensor head. Particle size measuring device. 7. The granule particle size measuring device according to claim 6, wherein an upper end of the arm member is swingably mounted on an upper surface of the granulating device. 8. The particle size measurement of a granulated product according to claim 6, wherein the granulation device is a stirring granulation device, a tumbling granulation device, a centrifugal flow granulation device, or a fluidized bed granulation device. apparatus. 9. The image processing apparatus according to claim 6, wherein the image processing apparatus calculates an average particle size of the powder using a volume basis or a number basis.
The granule particle size measuring device according to any one of the above.