JPH0953918A - Method for monitoring filled particles - Google Patents

Abstract

PROBLEM TO BE SOLVED: To process a large quantity of data with accuracy in a short time so as to accurately recognize filled particles by performing picture processing at the time of measuring the height of the deposited particles by scanning the surface of the deposited particles with a laser beam and detecting the reflected light of the laser beam. SOLUTION: The scanning extent of the surface S of piled up particles is divided into (m×n) matrices and the surface S is scanned with a laser beam 6 by successively projecting the beam 6 upon the points in the materices. The image of the beam 6 is picked up by several frames from each point with a camera. The several frames of pictures are integrated and the integrated picture which is most closely resemble to a preregistered picture of laser spot is selected. Then, the position of the gravity center of the picture is found and used as a laser spot. Thereafter, the pilled up particles are recognized with accuracy by picture processing, but, in order to shorten the picture processing time, the picture processing is only performed on a fixed range from the point which is estimated to be irradiated with the laser spot. When the picture processing is performed on the area of the surface S which is larger than the half of the maximum height of the surface S, namely, the square area having sides longer than the maximum height of the surface S, the piled up particles can be recognized with accuracy.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for monitoring particle packing in a container, and more particularly to a method for monitoring particle packing of catalysts and other particles in a container for synthesizing and decomposing various materials. . In particular, the present invention relates to an image processing method of catalyst filling monitoring by a trigonometric method using laser light in order to monitor in real time the uneven state of the deposition surface of the catalyst scattered in the reaction vessel for petroleum refining.

[0002]

BACKGROUND OF THE INVENTION It is often necessary to monitor the loading of particles in a container. For example, catalysts are used for the synthesis and decomposition of various materials. In the petroleum industry, catalysts such as a method of using a heavy diesel fuel as a raw material to make gasoline with a high octane number and a method of simultaneously performing desulfurization and decomposition using a catalyst in the presence of a large amount of hydrogen are used in the petroleum industry. Often. In the catalytic cracking method, for example, solid acidic silica, alumina particles, zeolite particles and the like are used as the catalyst. Generally, these catalysts are particles with a width of 0.5-3 mm and a length of 3-10 mm. In these cases,
Although the reaction vessel is filled with catalyst particles, the loading state of the catalyst particles influences the operation efficiency, so a loading device is installed above the center of the reaction vessel for the purpose of achieving uniform filling, and the catalyst particles are loaded from the loading device. Scatter filling is performed to make the cone fall in a conical shape.

However, even if spray filling is performed, the catalyst particle deposition surface is corrugated in an uneven shape, and a flat deposition surface cannot be obtained. When the unevenness exceeds a prescribed level, the operating efficiency is reduced, so it is necessary to correct the unevenness by controlling the spraying parameters provided in the filling device. Conventionally,
It is not easy to measure the unevenness of the deposited surface of the scattered particles because the reaction vessel is deep, and the measurement was performed by actually selecting an appropriate measurement point with a tape measure from the installation surface of the filling device. The measurement was carried out, for example, once every 30 minutes and with 12 measurement points. Therefore, it took a long time to perform the measurement, and the measurement was rough, and the measurement accuracy was poor, and the deposition surface distribution was ± 50 mm, and the maximum deposition surface distribution was 400 mm. Since the filling operation had to be stopped every time the measurement was performed, the filling operation efficiency was poor.

Therefore, in order to make the deposition surface of the particles dispersed in the container uniform, it is required to develop a technique for more accurately monitoring and measuring the unevenness of the deposition surface in real time prior to that. For example, in the case of filling the catalyst, a measurement accuracy of ± 20 mm on the uneven surface of the deposition surface is required.

In response to these demands, the applicant of the present invention firstly scans the deposition surface with a laser beam when the particles are filled in the container, detects the reflected light, and detects the position of a specific scanning point at the time of measurement and the laser. A particle filling monitoring method characterized in that the deposition height is measured from the light emission position and the laser light detection position by trigonometry, and the beam diameter of the laser light is selected at this time to be larger than the cross-sectional area of the particle and according to the target accuracy. And a laser having a laser beam diameter larger than the cross-sectional area of the particle for scanning the particle deposition surface with the laser beam and attached to the container for filling the particle at a level higher than the particle filling height and selected according to the target accuracy. An image pickup device that detects the laser reflection light from the light generation and scanning device and the scanning point, and the position of the specific scanning point at the time of measurement, the position of the laser light generation and scanning device, and the position of the imaging device. Developed a calculating device for calculating the depth of the scanning point, the particle packing monitoring device and a display device for displaying data including the deposition surface depth distribution by trigonometry. These use a laser beam to scan the particle deposition surface with a laser beam when filling the container with particles, detect reflected light, and measure the deposition depth at each scanning point at the required number of measurement points at a predetermined measurement interval. Basically, it is measured by the trigonometric method, and the deposition surface information including the height distribution of the deposition surface and an arbitrary cross-sectional trend passing through the center is displayed in real time.

FIG. 1 (a) shows a state in which catalyst particles C are scattered and packed in a conical shape from a packing device 3 installed at the center of the upper part of a reaction vessel 1, and the formed uneven corrugated catalyst. A state of the particle deposition surface S is shown, and a laser generation / scanning device 5 and an imaging device 9 as a particle filling monitoring device attached to the wall of the reaction vessel at substantially the same level as the filling device are shown. The laser generating and scanning device 5 generates a scanning laser beam 6. The image pickup device 9 detects the laser reflected light within a predetermined visual field. Furthermore, the computer 11 and the deposition surface depth as a calculation device for calculating the depth of the deposition surface at the scanning point by trigonometry from the position of a specific scanning point at the time of measurement, the position of the laser light generation / scanning device, and the position of the imaging device. CRT 13 as a device for displaying data including depth distribution
Is installed in the monitoring room at an appropriate position outside the reaction vessel,
A signal line 15 connects the laser generating and scanning device and the image pickup device. FIG. 1B is a cross-sectional view of the deposition surface S seen downward from the level of the filling device 3, the laser generation / scanning device 5, and the imaging device 9, showing the scanning aspect of the deposition surface S by the scanning laser beam 6. Show. The deposition surface is monitored by detecting the reflected light at the scanning points at regular intervals while scanning the deposition surface from the one end to the other end by the scanning laser beam 6 from side to side.

FIG. 2 shows how the laser generating and scanning device 5 and the image pickup device 7 are mounted on the container wall. The laser generation / scanning device 5 is composed of an appropriate laser source 7 such as a He—Ne laser or a semiconductor laser, and a laser scanner 8 which scans the laser beam left and right and back and forth so as to scan the deposition surface. The emission direction of the laser beam can be changed by sequentially changing the inclination of optical means such as a prism. The laser source 7 and the laser scanner 8 are disposed inside the dust-proof cover 17 connected to the air line 16 and immediately below the dust-proof cover 17 as dust-proof measures because catalyst dust is generated during the catalyst particle filling, and the dust-proof air is dust-proof from the air line 16. It is constantly blown out through the cover 17. The dust-proof cover 17 is attached to the wall of the reaction vessel by an appropriate fixing metal fitting 18. The image pickup device 9 is typically a CCD
The camera 10 is arranged inside the dustproof cover 19 which is also connected to the air line 16, and is attached to the wall of the reaction vessel by the fixing metal fitting 20. These are supported on a tray that centrally supports a filling device (not shown).

The field of view of the camera is the inner diameter of the reaction vessel, the CCD
Depending on the size of the image pickup surface, the focal length of the camera, and the distance to the deposition surface. For example, the inner diameter of the reaction vessel is 4 m, the CCD image pickup surface is 1/2 inch type, and the focal length f is 12 mm. In this case, the vertical field of view of the collected image is 3 m at a deposition surface distance of -10 m and a deposition surface distance of -5 m.
Since it is 1.5 m, there may be a situation where the entire view inside the reaction vessel cannot be monitored in the entire time range. In such a case, multiple cameras and possibly multiple laser generation and scanning devices may be used. For example, when using an imaging lens with a focal length of 9 mm, 4 cameras x 2 laser systems, 3 cameras x
A one-laser system or the like may be considered. FIG. 3 shows a 4 camera × 2 laser system. -5 m field of view and -10
The field of view of m is indicated by the dotted line. The 4-camera × 2-laser system allows a wider camera-laser interval than the 3-camera × 1 laser system, and enables wide-range and highly accurate measurement.

In the measurement of the deposition surface by scanning the laser beam, it is necessary that the laser beam surely reach the deposition surface at the bottom of the container. That is, it is necessary to prevent the laser beam from being blocked by the catalyst particles falling in the container space. It has been confirmed that the deposition surface can be measured by scanning the laser beam by setting the laser beam diameter to be equal to or larger than the cross-sectional area of the catalyst particles, preferably 10 times or more. The upper limit of the laser beam should be determined from the required measurement accuracy (several cm or less) and the brightness of the laser scanning point spot.
cm is the upper limit. For example, in order to achieve an accuracy of 5 cm, the upper limit of the diameter of the laser beam is 3 cm. Here, the cross-sectional area of the catalyst particle is the maximum projected area of the particle (the maximum value of the area of the shadow formed when the particle is irradiated with parallel light).

Control of the laser scanner, image processing from the image pickup device, and triangulation calculation are performed by a dedicated computer. The processed data is stored in a storage machine such as a magnetic disk or a magneto-optical disk and is displayed in real time on a CRT screen. Various filling information may be displayed on the CRT screen. FIG. 4 is a basic screen configuration diagram of a deposition surface monitor as an example. The distribution state of the deposition surface, the display of the deposition surface of the selected specific section, etc. are displayed in real time.

From the thus obtained information on the distribution of the deposition surface,
The state of spraying from the filling device is corrected so that the distribution of the deposition surface becomes constant. FIG. 5 shows an example of the filling device 3, (a)
Shows its side view and (b) shows the bottom slit. The side surface of the device is provided with four side surface slits 21 and the bottom surface 22 is provided with a lower slit 23 shown in (b). A rotating disk 24 is attached to the bottom surface. An adjustable door is provided in the side slit.
The lower slit 23 can also be adjusted. The spraying state can be controlled by adjusting the openings of the side and lower slits and the rotation speed of the rotary disk based on the obtained deposition surface information.

[0012]

This method for monitoring particle filling by laser light scanning makes it possible to monitor and measure the unevenness of the particle deposition surface in real time more accurately than before, but in actual observation. Therefore, there is room for improvement in terms of processing a large amount of data in a short time while maintaining accuracy and distinguishing accumulated particles from particles in spraying. An object of the present invention is to establish a processing procedure for performing these by image processing.

[0013]

When a particle deposition surface is scanned with a laser beam, the deposition surface is divided into m × n matrices, and the laser is sequentially irradiated to points on each matrix. For example, 10 × 10 = 100 points must be scanned in a short time. Therefore, when the image of the laser is taken by the camera, only a few frames can be usually taken in consideration of the time required for the image processing. The problem is that the falling particles traverse the laser path that is directed towards the points on the matrix of the deposition surface, making it difficult to identify the laser spot hitting the deposition surface. In one frame, particles that normally traverse many laser optical paths appear to shine. By integrating the images of several frames, the bright spots due to the scattered particles in the optical path become continuous lines. Here, by selecting the image closest to the image of the laser spot registered in advance,
It is possible to distinguish between the laser spot hitting the deposition surface and the bright spot due to the scattered particles in the optical path. Moreover,
The barycentric position of the preselected image is obtained and used as the coordinates of the laser spot. To reduce the time required for image processing,
The image is processed only within a certain range from the point where the laser spot is predicted to hit. From this point, image processing may be performed on a range of the maximum value of the unevenness of the deposition surface (depth direction) / 2 or more, that is, a rectangular range in which one side is the maximum value of the unevenness of the deposition surface (depth direction) or more.

Thus, according to the present invention, when the container is filled with particles, the deposition surface is scanned with laser light, reflected light is detected, and the position of a specific scanning point at the time of measurement, the laser light emission position and the laser light detection. In the particle filling monitoring method that measures the deposition height from the position by trigonometry, the deposition surface is divided into an m × n matrix, and the points on the matrix are sequentially irradiated with a laser beam for scanning, and collected at each point. The image of several frames is integrated and the image closest to the laser spot image registered in advance is selected, the center of gravity position of the image is calculated, and image processing is performed as the laser spot. From the point of view of the above, there is provided a particle filling monitoring method characterized by performing image processing only within a predetermined range of the maximum value (depth direction) / 2 of the unevenness of the deposition surface.

Thus, in the present invention, the scanning range of the deposition surface is divided into an m × n matrix, and the particles on the matrix are sequentially irradiated with laser to scan the particle deposition surface. The camera captures several frames of the laser image. The image of several frames is integrated, the image closest to the image of the laser spot registered in advance is selected, and the position of the center of gravity of the image is determined and used as the laser spot. Accurate recognition of the deposited particles is performed by image processing, but in order to reduce the time required for image processing, image processing is performed only within a certain range from the point where the laser spot is predicted to hit. From that point, if the range of the maximum value of the unevenness of the deposition surface (in the depth direction) / 2 or more, that is, the square range in which one side is the maximum value of the unevenness of the deposition surface (in the depth direction) or more is image-processed, the accuracy of the deposited particles will be improved. You can make a good recognition.

[0016]

BEST MODE FOR CARRYING OUT THE INVENTION As described above with reference to FIG. 1, the method of the present invention uses a filling device for conical spraying of particles C from a filling device 3 installed in the upper center of the reaction vessel 1. A deposition surface of the corrugated catalyst particles which is being formed by the laser generation / scanning device 5 and the imaging device (camera) 9 as a particle filling monitoring device attached to the wall of the reaction vessel at almost the same height level. Filling is performed while monitoring the state of S. Laser generation and scanning device 5
Produces a scanning laser beam 6. The imaging device 9 collects an image within a predetermined visual field and detects laser reflected light. The deposition surface is monitored by detecting the reflected light at the scanning points at regular intervals while scanning the deposition surface from the one end to the other end by the scanning laser beam 6 from side to side. Further, a computer 11 as a calculation device / image processing device for calculating the depth of the deposition surface at the scanning point by trigonometry from the position of a specific scanning point at the time of measurement, the position of the laser beam generating / scanning device and the position of the image pickup device. A CRT 13 that displays data including the depth distribution of the deposition surface is installed in a monitoring room at an appropriate position outside the reaction container. The field of view of the camera is the inner diameter of the reaction vessel, C
Depending on the size of the imaging surface of the CD, the focal length of the camera, and the distance to the deposition surface, a plurality of cameras and a plurality of laser generation / scanning devices may be used so that the entire internal view of the reaction vessel can be monitored in all time zones. . For example, when using an imaging lens with a focal length of 9 mm, 4 cameras x 2 laser systems, 3 cameras x
A one-laser system or the like may be considered.

As a processing procedure of the particle filling monitoring, as shown in FIG. 6, first, as initialization, the absolute coordinate system of the camera 10, the position of the laser, the imaging angle of the camera 10, the swing angle of the laser scanner 8 and three points are set. Input the absolute coordinate system of the marker M. After that, the laser spot is aligned with the marker, the position of the marker is measured by the image processing device, and the mounting direction of the laser scanner and the orientation of the camera are corrected. The scanning range on the bottom surface (deposition surface) is calculated from the data in the absolute coordinate system.

The scanning range is divided into a matrix of m × n, for example, 10 × 10, and the points on each matrix are sequentially irradiated with a laser to scan the particle deposition surface with laser light. In advance, a table is used to determine which laser is applied to which point and which laser image is to be collected by which camera. As the particle filling progresses, the deposition surface gradually becomes higher, and the visual field range between the camera and the laser changes. Therefore, the combination table of the camera and the laser can be changed for each height of the filling surface. For example, it is possible to have 20 combination tables with a height of 1 cm, and the combination table is changed as the particle packing height progresses.

A laser image to a point on each matrix is taken by a camera, but since scanning must be performed in a short time, for example, 10 × 10 = 100 points must be scanned within 30 seconds, Considering the time required for image processing at the maximum of several tens of frames per point, normally only several frames can be sampled. It is recommended that the number of frames be 3 or more because of accuracy and 10 or less because of processing time.

The particles scattered and accumulated in the container fall in the container at a certain average spatial density according to the amount of dispersion, the size and falling speed of the particles, the size of the container and the like. The exposure time per one frame of an image is determined according to the number of matrices, the scanning time, the image processing time, etc., but is usually a short time of several tens of seconds. However, there are a significant number of particles that traverse the laser light path during one frame, which makes them appear to shine.

The frame memory associated with the camera is made up of vertical and horizontal groups of pixels, which means that particles that cross the laser beam path produce bright spots, for example, every few pixels. Therefore, when the images for several to ten frames are integrated, the bright spots due to the scattered particles that cross the laser optical path become a continuous line as shown in FIG. The image closest to the image of the laser spot registered in advance as shown in FIG. 8 is selected, and the position of the center of gravity of the image is determined and used as the coordinates of the laser spot. To reduce the time required for image processing,
The image is processed only within a certain range from the point predicted from the calculation that the laser spot hits. From this point, image processing may be performed on a range of the maximum value of the unevenness of the deposition surface (depth direction) / 2 or more, that is, a rectangular range in which one side is the maximum value of the unevenness of the deposition surface (depth direction) or more. The maximum value of the unevenness of the deposition surface is updated every measurement of the m × n matrix. In addition, until the initial state of spraying (until particles are deposited up to the maximum (target) value of the unevenness of the deposition surface required for spraying), the maximum value of the unevenness of the deposition surface is the deposition surface required for spraying. The maximum (target) value of the unevenness of can be substituted. Further, not only at the initial stage of the spraying but also until the end of the spraying, the maximum value of the unevenness of the deposition surface is not used for the image processing, and the image processing may be performed with this value being constant. For example, image processing is performed only in the range of 40 cm to 1 m around the point predicted to hit the laser spot.

After such image processing, the distance between the point where the laser hits is obtained from the absolute coordinate system of the laser and the camera, the swing angle of the laser, and the coordinates of the laser spot. This scan is repeated for points in all matrices.
When the measurement at all points is completed, the average value of the measured distances is calculated and used as the reference value for the next laser measurement, and the laser irradiation position is recalculated. After this, graphic output is performed. A flowchart of such an image processing flow is shown in FIG.

[0023]

EXAMPLE A filling device was fixed to a steel cylindrical container having a diameter of about 3 m and a height of about 18 m at a distance of about 5 m from the upper end of the container, and a diameter of 0.
Cylindrical ceramic catalyst particles having a diameter of 5 to 1.5 mm and a length of 3 to 5 mm (cross-sectional area: 0.0152 cm ^{2 to} 0.07
83 cm ² ) was spatially sprinkled at a deposition rate of about 1 m / hour, the deposition surface was scanned with a laser beam, and the unevenness of the deposition surface was measured. The number of matrix measurement points is 10 x 1
0 was set as 100 points, and the measurement interval was set to approximately once every 30 seconds.
Images of 5 frames were collected for each point. The measurement was performed by semiconductor laser beam scanning and triangulation of the deposition surface with a CCD camera. As the laser beam, a 30 mW semiconductor laser was used. The laser beam diameter was 10 mm.
A 1/2 inch 380,000 pixel monochrome CCD camera with a focal length of 8 mm was used as the camera (minimum subject illuminance: 0.
2 Lux). A 512 × 512 pixel image processing device was used (the recognition accuracy was determined as the coordinates of the laser spot in 0.1 pixel units). The exposure time of the camera was 1/60 seconds per frame. Only the range of 40 cm to 1 m around the point calculated to hit the laser spot was image-processed. A measurement accuracy of ± 17 mm was obtained at a distance of 10 m to the deposition surface and a measurement accuracy of ± 10 mm at a distance of 5 m to the deposition surface.

Although the monitoring of the filling of the catalyst particles into the reaction vessel has been particularly described above, the present invention is not limited to the above-mentioned embodiment, and the container of other particles such as the monitoring of the filling of the storage silo with the grains. It can be widely applied to filling monitoring. The particles are not particularly limited, but non-isotropic particles for which filling control of particles is difficult and there is a high need for filling monitoring, for example, particles having an aspect ratio (major axis / minor axis) of 2 or more are preferable targets. It

[0025]

As described above, when the particle deposition surface in the container is scanned with the laser beam and the reflected light is detected to measure the deposition height by the trigonometric method, a large amount of data can be shortened while maintaining the accuracy by image processing. It was possible to process in time, to distinguish between deposited particles and particles in spraying, and to perform accurate recognition of deposited particles.

[Brief description of drawings]

FIG. 1 (a) shows the arrangement of devices for spraying and filling particles from a filling device in a reaction vessel, measuring the state of a deposition surface, and displaying it, and FIG. 1 (b) shows scanning. It is explanatory drawing which shows the aspect of the scanning of the deposition surface by a laser beam.

FIG. 2 is an explanatory diagram showing a manner in which a laser generation / scanning device and an imaging device are attached to a container wall.

FIG. 3 shows a laser and camera arrangement example of a 4-camera × 2-laser system, and a -5 m field of view and a -10 m field of view are shown by dotted lines.

FIG. 4 is a basic screen configuration diagram of a deposition surface monitor.

FIG. 5 shows an example of a filling device, (a) a side view and (b) a bottom slit.

FIG. 6 is an explanatory diagram showing an imaging angle of a camera, a swing angle of a laser scanner, and an absolute coordinate system and a matrix of three markers.

FIG. 7 is an explanatory diagram showing that bright points formed by scattered particles traversing a laser optical path become a continuous line as a result of integration of images for frames.

FIG. 8 shows an example of a laser spot image registered in advance.

FIG. 9 is a flowchart of an image processing flow.

[Explanation of symbols]

 C catalyst particles S catalyst particle deposition surface 1 reaction vessel 3 filling device 5 laser generation and scanning device 6 scanning laser beam 7 laser source 8 laser scanner 9 imaging device 10 camera 11 computer 13 CRT 15 signal line 16 air line 17, 19 dust cover 18, 20 Fixing bracket 21 Side slit 22 Bottom surface 23 Lower slit 24 Rotating disk M Marker

Claims (2)

[Claims] 1. When filling a container with particles, a deposition surface is scanned with a laser beam, reflected light is detected, and a position of a specific scanning point at the time of measurement, a laser beam emitting position, and a laser beam detecting position are triangulated. In the particle filling monitoring method of measuring the deposition height by, the deposition surface is divided into m × n matrix, and laser is sequentially irradiated to points on the matrix to perform scanning,
Image of several frames collected at each point is integrated and the image closest to the image of the laser spot registered in advance is selected, the center of gravity of the image is determined, and image processing is performed to make the laser spot, and the laser A particle filling monitoring method, wherein image processing is performed only within a predetermined range equal to or larger than the maximum value (depth direction) of the unevenness of the deposition surface from the point predicted to hit the spot. 2. The particle filling monitoring method according to claim 1, wherein the particles are catalysts.