JPS63279138A - Method and apparatus for measuring particle size distribution - Google Patents

Abstract

PURPOSE:To achieve an on-line application in the measurement of a particle size distribution, by performing a 2-D accumulation of an optical image of particle material moving in a space to analyze. CONSTITUTION:A bar-like light source is arranged in front of a linear sensor camera 1. Particulate material 3 is conveyed with a sample supply conveyor 4, drops naturally at the tip of the conveyor and passes a measuring point within a field of view of the linear sensor camera 1. 1-D information corresponding to the width of each particle from the linear sensor camera 1 is written into image memories 5, 5', 5''... sequentially to obtain 2-D information as plane image of each particle. Information per screen on a memory is transferred to a large-capacity recorder 6 sequentially. The large-capacity recorder 6 transfers information in dispersion per screen to a plurality of image analyzers 7, 7', 7''... after recording for specified screens to perform a calculation of a classification data. The data thus obtained is transmitted to a controller 8 to be displayed on a printer 9 and a CRT 10 as particle size distribution data.

Description

Detailed Description of the Invention [Industrial Application Field] The present invention relates to a system for optically measuring the particle size distribution of each particulate material such as ore, coke, pellets, etc. when the particulate material is supplied by a conveyor or the like. It is related to the device.

[Prior Art] Conventionally, as a device for measuring the particle size distribution of this type of particulate material, there is a sieve made corresponding to each classification point. The weight of the particle material was measured for each classification, and the particle size distribution was calculated.

[Problems that 93 Mei attempts to solve] When calculating the particle size distribution by manually sieving the particulate material and measuring the weight of each classification, it takes a long time to measure, and therefore it takes a long time. , online measurements were not possible.

The present invention eliminates the above-mentioned drawbacks, and enables automation and simplification of the system by optically measuring the particle size distribution of each particle material online and effectively using the measurement results as a control factor for each device. It is an object of the present invention to provide a system and apparatus for measuring the particle size distribution of particulate materials.

[Means and effects for solving the problem] The particle size distribution 4X determination system of the present invention obtains a one-dimensional image of the particulate material by optical means during the process of the particulate material falling or moving in space, and It is characterized by sequentially recording images of the shaped material in a plurality of image memories, sequentially transferring images from the image memory in which one screen has been formed to a large-capacity recording device, and continuously recording a predetermined screen on this recording device. do.

Images recorded in the large-capacity recording device are transferred one screen at a time to a plurality of image analysis devices for distributed analysis.

The particle size distribution measuring device of the present invention includes an optical device that takes out an optical image of particulate material falling or moving in space, an image memory that two-dimensionally stores images of the particulate material from this optical device, and a a large-capacity recording device that records the output;
It is characterized by comprising an image analysis device that analyzes data from this recording device, and a controller that integrates the data from this image analysis device and supplies particle size distribution data to a printer, a display device, or a computer.

The present invention will be explained below with reference to the drawings.

Figure 1 shows a basic configuration block diagram of a device implementing the system of the present invention. In Figure 0, 1 is a linear sensor camera that constantly scans at scan intervals corresponding to the falling speed of the granular material at the measurement point, which will be described later. ing. A rod-shaped light fi2 is arranged in front of this linear sensor camera l. This light source 2
The particulate material 3 is conveyed by a material supply conveyor 4 and naturally falls at the tip of the conveyor, and a linear sensor formed by a linear sensor camera l and a rod-shaped light source 2 is used as a particulate material 3. It is possible to pass through the measurement point within the field of view of camera l. That is, the linear sensor camera l can obtain one-dimensional information corresponding to the particle width for each scan. By sequentially writing this -dimensional information into the image memories 5.5', 5', . . . , two-dimensional information as a planar image of each particle can be obtained.

The principle of such a system has already been proposed in Japanese Patent Application No. 57-19080.
Although it is described in the specification of No. 9, the relationship among the field of view width, falling speed, and scanning interval is shown below just in case.

The operation interval of the linear sensor camera l must be determined so that the aspect ratio of the resolution is equal. The directional resolution tb is 1 mm per bit, and therefore, in order to reduce the longitudinal resolution f to 1 foot/scan, the operating interval T must be set to 1 for the falling velocity of the particle material at the measurement point.
It is necessary to take the time to move mm.9 For example, if the falling measurement of the object at the measurement point is 5■11+/sec, the operation interval T = 5xlo3 = 0.0002sec =
The concept of the video signal from the 2001Lsee linear sensor camera I is shown in FIG.

At scan No. 0, the particle as the object has not yet reached the imaging position t of the camera, so the video signal from the camera is in a flat state. In scan No. 1, the lower part of the particle reaches the imaging position δ, and this blocks the light from the rod-shaped light source 2, so the output level of the corresponding bit on the linear sensor is reduced.

The particle position moves as the scan number becomes 2.3.4, and the number of corresponding bits increases accordingly.
At scan No. 6, the upper limit of particles is imaged, and at scan No. 7, the particles flow out again from within the field of view of the linear sensor camera l, and the video signal becomes flat.

In Fig. 1, 5.5', 5''... indicate a plurality of mutually independent image memories, and the video signal from camera l is sent to the image memory 5.5', 5''... for each screen. The memory that has been written to IIn and has completed writing for one screen on the memory will sequentially transmit data to a large-capacity recording bag δ6 such as a disk recorder to prepare for the next writing.

A large-capacity recording bag δ6 such as a disk recorder is an image analysis device 7.7' for recording and viewing a predetermined screen.

7''..., the classification data is calculated using the optimal software, and this data is transmitted to the controller 8.The controller 8 is connected to each image analysis device 7, 7', 7
The data from ``...'' are combined and displayed as particle size distribution data on a printer 9.CRTIO, etc., and also transmitted to a host computer.

An example of the granularity 4j data displayed on the CRTIO is shown as 10' in FIG.

As described above, according to the system of the present invention, particle size distribution can be measured online.

[Example] An embodiment of the device of the present invention will be described with reference to FIG.

A shading correction circuit 11 outputs a shading correction signal for correcting the imbalance of the video signal due to uneven illumination to the video signal taken in from the camera l to the addition circuit 12 in accordance with the scanning position. The adding circuit 12 adds the video signal from the camera 1 and the shading correction signal so that a flat video signal can be output when there are no particles within the field of view of the camera.

The A/D converter 13 digitizes the analog level video signal. The threshold level setter 14 sets a threshold for binarizing the digital video signal. Therefore, the comparator 15 compares the threshold level from the setter 14 with the output of the A/D converter 13. By comparison, when the video signal level is high, a binary signal “1” is output, and conversely, when the video signal level is low, a z-value signal “0” is output.
Output.

A clock oscillator 16 generates a memory write clock equal to the shift clock of the linear sensor camera l and a memory read clock equal to a standard TV scan. Clock switching circuits 17 and 18 are memory control circuit 2, which will be described later.
5, the write clock and the read clock are controlled to be selectively output alternately for each screen.

Address counters 19 and 20 count the clocks output from clock switching circuits 17 and 18, and output memory address 19'.

20' is output and supplied to image memories 21 and 22, respectively. These image memories 21 and 22 are independent image memories, and are controlled by the memory control circuit 25 so that when one is in the write mode, the other is in the read mode. For a memory set to write mode, the output of the comparator 15 is written to the memory address specified by the corresponding address counter 19 or 20.
For example, if the video signal level is lower than the threshold level, it is determined that it is a particle image, and the θ level is written in the memory. The memory control circuit 25 controls the clock switching circuits 17 and 18 in accordance with the timing of the horizontal synchronization signal 27 and the vertical synchronization signal 28, and sets the write mode or read mode of the image memories 21 and 22. That is, one image memory is in the write mode. When set to mode, the corresponding address counter is given the write clock,
The other memory is set to read mode, and the corresponding address counter is given a read clock equal to a standard TV scan, reads the data written one frame cycle ago, and transfers this data to the memory switching circuit 23.
The signal is inputted to the synchronization signal addition circuit 24 via.

A synchronization signal addition circuit 24 adds a horizontal synchronization signal 27 and a vertical synchronization signal 28 to the binarized video signal and outputs the result as a composite video signal to a disk recorder 29 for recording. For the disk recorder 29, the controller 30 performs mode settings such as recording, i'f'L, fast forward, fast reverse, forward rotation, reverse rotation, address set, and address search. For example, the controller 30 performs memory control. circuit 25
When it receives a memory allocation completion signal, it outputs the normal rotation and recording mode to the disk recorder 29, so that the composite video signal output from the synchronization signal addition circuit 24 can be recorded. After recording a predetermined number of screens, the controller 30 sets the top address at the start of recording, searches for a playback start address in a search mode, and sends a video signal from the first screen to the image analysis types 2131 and 32 alternately after waiting for an analysis completion signal.

The image analysis types 2131 and 32 each calculate classification data for a predetermined number of screens using optimal software, and transmit the results to the controller 30. The controller 30 is connected to both analysis devices 31
The results of steps 32 and 32 are combined and output as particle size distribution data to a display device such as a CRT 9 and a recording device such as a printer 10, and the results are also transmitted to a host computer.

[°Effects of the Invention] As described above, according to Kiba II, all particle size distributions of particle materials can be determined online, and therefore measurement can be automated.

[Brief Description of the Drawings] Fig. 1 is a block diagram showing an apparatus for implementing the particle size distribution measuring system of the present invention, and Fig. 2 shows the state of the output video signal fEi of the linear sensor camera.
FIG. 3 is a block diagram showing the detailed configuration of the particle size distribution measuring device of the present invention. 1... Linear sensor camera 2... Rod-shaped light source 3... Particulate material 4... Material conveyor 5.5', 5", 21.22... Image memory 6.29
...Disk recorder 7.7', 7'', 31.32...Image analysis device 8.3
0...Controller 11...Shading correction circuit 12...Addition circuit 13...A/D converter 14...Threshold setter 15...Comparator 16...Clock oscillator 17.18... ... Clock switching circuit 19.20 ... Address counter 23 ... Memory switching circuit 24 ... Periodic signal addition circuit 25 ... Memory control circuit 26 ... Synchronization signal generator 27 ... Horizontal synchronization signal 28...Vertical synchronization signal

Claims (6)

[Claims] (1) In the process of the particulate material falling or moving in space, a one-dimensional image of the particulate material is obtained by optical means, and this particulate material image is sequentially recorded in multiple image memories to form one screen. A particle size distribution measuring method characterized by sequentially transferring images from an image memory that has completed the process to a large-capacity recording device, and continuously recording predetermined screens on this recording device. (2) The particle size distribution measuring method according to claim 1, wherein the images recorded in the large-capacity recording device are transferred one screen at a time to a plurality of image analysis devices for dispersion analysis. (3) The particle size distribution measuring method according to claim 1, wherein the optical device includes a rod-shaped light source and a linear sensor camera. (4) The particle size distribution measuring method according to claim 1, wherein the large-capacity recording device is a disk recorder. (5) An optical device that takes out an optical image of particulate material falling or moving in space, an image memory that primarily stores images of the particulate material from this optical device, and a large memory that records the output of this image memory. It is characterized by comprising a capacitance recording device, an image analysis device that analyzes data of this recording device, and a controller that integrates the data of this image analysis device and supplies particle size distribution data to a printer, a display device, or a computer. Particle size distribution measuring device. (6) The particle size distribution measuring device according to claim 5, wherein the optical device includes a rod-shaped light source and a linear sensor camera.