Particle size distribution measuring device and particle size distribution measuring method

Abstract

The application provides a particle size distribution detection device for particles, comprising a first vibrating screen assembly, a first optical structure, a first tray and a first screen; the first optical structure is used for emitting first laser to irradiate particles to be detected in a detection space, generating a first detection signal; the first tray is used for weighing the first mass of the particles to be detected; a second vibrating screen assembly is formed with a second detection space, used for obtaining the second mass of part of the particles to be detected passing through the first screen, and generating a second detection signal according to the part of the particles to be detected; a controller is used for obtaining the light intensity angle distribution of the first detection light according to the first detection signal, obtaining the light intensity angle distribution of the second detection light according to the second detection signal, and obtaining the particle size-volume distribution information of at least part of the particles to be detected according to the light intensity angle distribution, the first mass and the second mass based on a normal distribution curve. The application also provides a particle size distribution detection method.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of screening, and in particular to a particle size distribution detection device and a particle size distribution detection method applied to the particle size distribution detection device. BACKGROUND

[0002] The existing vibration screening technology can be used to roughly estimate the content proportion of particles of various particle sizes in a sample to be measured, but it is difficult to accurately obtain the distribution information of particles of different particle sizes. SUMMARY

[0003] The first aspect of the present application provides a particle size distribution detection device, comprising: a first vibration screening assembly, comprising a first main body, a first optical structure, a first tray and a first screen, the first main body enclosing a first detection space, the first optical structure, the first tray and the first screen being located in the first detection space and connected to the first main body; the first optical structure is used to emit first laser light to irradiate particles to be measured located in the detection space, and is used to receive first detection light scattered by the particles to be measured according to the first laser light to generate a first detection signal, the first tray is used to weigh a first mass of the particles to be measured, and the screen is used to screen out part of the particles to be measured; a second vibration screening assembly forms a second detection space, the second vibration screening assembly and the first vibration screening assembly are arranged in sequence along a predetermined direction, the second vibration screening assembly is used to obtain a second mass of part of the particles to be measured passing through the first screen, and is used to generate a second detection signal according to the part of the particles to be measured; and a controller is electrically connected to the first optical structure, the first tray and the second vibration screening assembly respectively, the controller is used to obtain an intensity-angle distribution of the first detection light according to the first detection signal, and obtain an intensity-angle distribution of second detection light according to the second detection signal, and is further used to obtain "particle size-volume" distribution information of at least part of the particles to be measured based on a normal distribution curve, according to the intensity-angle distribution, the first mass and the second mass.

[0004] The second aspect of the application provides a particle size distribution detection method of particles, which is applied to a particle size distribution detection device of particles, the particle size distribution detection device of particles comprises a first vibrating screen assembly and a second vibrating screen assembly arranged in sequence along a preset direction, the first vibrating screen assembly forms a first detection space, and the second vibrating screen assembly forms a second detection space; the particle size distribution detection method of particles comprises the following steps: controlling the to-be-detected particles to enter the first detection space; controlling first laser to be emitted and first detection signals generated by first detection light scattered by the to-be-detected particles according to the first laser to be received, acquiring the light intensity angle distribution of the first detection light according to the first detection signals, and weighing the first mass of the to-be-detected particles; controlling part of the to-be-detected particles to enter the second detection space, the particle size of the part of the to-be-detected particles being smaller than the particle size of the remaining to-be-detected particles; controlling second laser to be emitted and second detection signals generated by second detection light scattered by the part of the to-be-detected particles according to the second laser to be received, acquiring the light intensity angle distribution of the second detection light according to the second detection signals, and weighing the second mass of the part of the to-be-detected particles; and based on a normal distribution curve, acquiring the particle size-volume distribution information of at least part of the to-be-detected particles according to the light intensity angle distribution, the first mass and the second mass.

[0005] The particle size distribution detection device and the particle size distribution detection method of particles, the first vibrating screen assembly comprises a first optical structure, a first tray receiver and a first screen, the to-be-detected particles are optically detected by the first optical structure to obtain first detection signals, the to-be-detected particles are weighed by the first tray receiver to obtain a first mass, and the particle size of the to-be-detected particles is screened by the first screen and the second vibrating screen assembly, so that the particle size-volume distribution information of at least part of the to-be-detected particles can be accurately acquired based on a normal distribution curve according to the light intensity angle distribution, the first mass and the second mass. BRIEF DESCRIPTION OF DRAWINGS

[0006] Figure 1 It is a structural schematic diagram of the particle size distribution detection device of particles in the embodiment of the application.

[0007] Figure 2 It is Figure 1 It is a sectional structural schematic diagram of the first vibrating screen assembly, the second vibrating screen assembly and the third vibrating screen assembly along line II-II.

[0008] Figure 3 It is a step flow schematic diagram of the particle size distribution detection method of particles in the embodiment of the application.

[0009] Figure 4 It is the angle and intensity corresponding relationship of detection light.

[0010] Figure 5Fig. 2 is a schematic view of a "particle size-volume" distribution curve of all the particles to be measured obtained according to the first sieve assembly.

[0011] Figure 6 Fig. 3 is a schematic view of a "particle size-volume" distribution curve of part of the particles to be measured obtained according to the second sieve assembly.

[0012] Figure 7 Fig. 4 is a schematic view of a "particle size-volume" distribution curve of part of the particles to be measured obtained according to the third sieve assembly.

[0013] Figure 8 Fig. 5 is a schematic view of a "particle size-volume" distribution curve of the particles to be measured in the target particle size range fitted by the controller.

[0014] Main element symbol explanation

[0015] Particle size distribution detection device: 100; second sieve: 24; first sieve assembly: 10; third sieve layer: 241; first main body: 11; first mesh: 2411; first detection space: 111; fourth sieve layer: 242; first optical structure: 12; second mesh: 2421; first light emitting element: 121; second funnel structure: 25; first detection element: 122; second funnel: 251; first tray: 13; second closure: 252; first sieve: 14; third sieve assembly: 30; first sieve layer: 141; third main body: 31; second mesh: 1411; third detection space: 311; second sieve layer: 142; third optical structure: 32; third mesh: 1421; third light emitting element: 321; first funnel structure: 15; third detection element: 322; first funnel: 151; third tray: 33; first opening: 1511; third sieve: 34; first closure: 152; fifth sieve layer: 341; second sieve assembly: 20; fifth mesh: 3411; second main body: 21; sixth sieve layer: 342; second detection space: 211; sixth mesh: 3421; second optical structure: 22; third funnel structure: 35; second light emitting element: 221; third funnel: 351; second detection element: 222; third closure: 352; second tray: 23; steps: S1, S2, S3, S4, S5.

[0016] The following detailed description will further illustrate the present application in conjunction with the above-mentioned drawings. DETAILED DESCRIPTION

[0017] The application provides a particle size distribution detection device and a particle size distribution detection method applied to the particle size distribution detection device, which are used for detecting the particle size distribution of particles to be detected. The particle size distribution detection device comprises a vibrating screen assembly, which is used for screening and optically detecting the particles to be detected through a screen and an optical structure, so as to accurately obtain the "particle size-volume" distribution information of at least part of the particles to be detected.

[0018] Referring to Figure 1 The particle size distribution detection device 100 can be used for detecting the particle size distribution of the particles to be detected 200 with a particle size less than 1000 μm (for example, tens to hundreds of microns). The particle size distribution detection device 100 is used for detecting the particle size distribution of the particles to be detected 200, and further obtaining the "particle size-volume" distribution information of part of the particles to be detected 200 with a particle size range in at least one target particle size range.

[0019] The particle size distribution detection device 100 comprises a first vibrating screen assembly 10, a second vibrating screen assembly 20, a third vibrating screen assembly 30 and a controller 40. The first vibrating screen assembly 10, the second vibrating screen assembly 20 and the third vibrating screen assembly 30 are arranged in sequence from top to bottom (as a reference) in the direction, and are detachably connected between any two adjacent vibrating screen assemblies. The controller 40 is connected to the first vibrating screen assembly 10, the second vibrating screen assembly 20 and the third vibrating screen assembly 30 respectively. Figure 1 The particle size distribution detection device 100 comprises a first vibrating screen assembly 10, a second vibrating screen assembly 20, a third vibrating screen assembly 30 and a controller 40. The first vibrating screen assembly 10, the second vibrating screen assembly 20 and the third vibrating screen assembly 30 are arranged in sequence from top to bottom (as a reference) in the direction, and are detachably connected between any two adjacent vibrating screen assemblies. The controller 40 is connected to the first vibrating screen assembly 10, the second vibrating screen assembly 20 and the third vibrating screen assembly 30 respectively.

[0020] During the working process of the particle size distribution detection device 100, the particles to be detected 200 are controlled to pass through the first vibrating screen assembly 10, the second vibrating screen assembly 20 and the third vibrating screen assembly 30 in sequence, so as to sequentially perform optical detection, weight detection and particle size screening on at least part of the particles to be detected 200. The controller 40 is used for controlling the working of the first vibrating screen assembly 10, the second vibrating screen assembly 20 and the third vibrating screen assembly 30, and processing and calculating the signals output by the first vibrating screen assembly 10, the second vibrating screen assembly 20 and the third vibrating screen assembly 30 during the working process, so as to obtain the "particle size-volume" distribution information of the particles to be detected 200. The controller 40 comprises a terminal device such as a computer.

[0021] In this embodiment, the particle size distribution detection device 100 comprises three layers of vibrating screen assemblies (the first vibrating screen assembly 10, the second vibrating screen assembly 20 and the third vibrating screen assembly 30), which are taken as examples to illustrate the structure and function of the particle size distribution detection device 100. In other embodiments of the application, the particle size distribution detection device 100 can comprise a smaller or larger number of vibrating screen assemblies. In other embodiments of the application, the vibrating screen assemblies can also be stacked in sequence and fixedly connected.

[0022] Referring to Figure 2The first vibration and screening assembly 10 comprises a first main body 11, a first optical structure 12, a first tray 13 and a first screen 14. The first main body 11 encloses a first detection space 111, and the first optical structure 12, the first tray 13 and the first screen 14 are located in the first detection space 111 and connected to the inner wall of the first main body 11. When the particles 200 to be detected enter the first detection space 111, the first optical structure 12 is used for optical detection of the particles 200 to be detected, the first tray 13 is used for weight detection of the particles 200 to be detected, and the first screen 14 is used for particle size screening of the particles 200 to be detected.

[0023] In the embodiment, the first optical structure 12, the first tray 13 and the first screen 14 are arranged in sequence from top to bottom and are spaced apart from each other. That is, the first tray 13 is located between the first optical structure 12 and the first screen 14, and the first screen 14 is closer to the second vibration and screening assembly 20 than the first optical structure 12. In this way, the particles 200 to be detected entering the first detection space 111 are first subjected to optical detection by the first optical structure 12, then subjected to weight detection by the first tray 13, and finally subjected to particle size screening by the first screen 14.

[0024] The application does not limit the order of optical detection and weight detection. In other embodiments of the application, the positional relationship between the first optical structure 12 and the first tray 13 can be exchanged. That is, in other embodiments of the application, the first optical structure 12 can be located between the first tray 13 and the first screen 14, and the particles 200 to be detected entering the first detection space 111 are first subjected to weight detection by the first tray 13, then subjected to optical detection by the first optical structure 12, and finally subjected to particle size screening by the first screen 14.

[0025] The first optical structure 12 comprises a plurality of first light emitting elements 121 and a plurality of first detection elements 122. Each first light emitting element 121 is spaced apart on the inner wall of the first main body 11, and each first detection element 122 is also spaced apart on the inner wall of the first main body 11. In the embodiment, the plurality of first light emitting elements 121 are arranged in a plurality of parallel rows, and each first light emitting element 121 in the same row is spaced apart in the circumferential direction on the inner wall of the first main body 11. Each first detection element 122 is also arranged in a plurality of parallel rows, and each first detection element 122 in the same row is also spaced apart in the circumferential direction on the inner wall of the first main body 11. One row of first light emitting elements 121 and one row of first detection elements 122 are staggered in the arrangement direction of each vibration and screening assembly.

[0026] The first light emitting element 121 is a light emitting diode, which is configured to emit a first laser light towards the center of the first detection space 111. When the particles 200 to be detected enter the first detection space 111, the first laser light irradiated to the surface of the particles 200 to be detected is scattered by the particles 200 to be detected as first probe light. The first probe element 122 is a photodiode, which is configured to receive the first probe light and output a corresponding first probe signal (an electrical signal) after generating the first probe signal. The controller 40 is configured to receive the first probe signals output by the first probe elements 122. The amplitude of the first probe signal generated by each first probe element 122 can reflect the intensity of the first probe light at the position of the first probe element 122. The controller 40 can obtain the angular distribution of the first probe light by analyzing the amplitudes of the first probe signals output by all the first probe elements 122. The working process of the first light emitting element 121 and the first probe element 122 described above is the aforementioned “optical detection” process.

[0027] The above arrangement of the first light emitting element 121 and the first probe element 122 is conducive to projecting the first laser light to any position and angle in the first detection space 111, and conducive to receiving the first probe light from any position and angle in the first detection space 111. In at least one embodiment of the present application, the first laser light and the first probe light can be blue light or red light.

[0028] The first tray 13 is a disc-shaped structure that is adapted to the shape of the first detection space 111. By means of the built-in weighing electronic element (not shown in the figure), the first tray 13 can realize weighing all the particles 200 to be detected to output a first mass after all the particles 200 to be detected fall into the first tray 13. In at least one embodiment of the present application, the first tray 13 can be controlled by the controller 40 to be in a closed state and an open state. When the first tray 13 is in the closed state, it is configured to receive the particles 200 to be detected after optical detection and weigh the particles 200 to be detected. When the first tray 13 is in the open state, it is configured to pour the particles 200 to be detected after weighing to the first sieve 14 below. The controller 40 controls the first tray 13 to remain in the closed state during the optical detection process, and controls the first tray 13 to switch to the open state after all the particles 200 to be detected complete the optical detection and fall into the first tray 13 to end the weighing.

[0029] In the embodiment, the first screen 14 comprises a first screen layer 141 and a second screen layer 142 which are sequentially and spacedly stacked. The first screen layer 141 and the second screen layer 142 each has a circular outer contour which is adapted to the shape of the first detection space 111. The first screen layer 141 is formed with a plurality of first screen holes 1411 which are densely arranged and have equal aperture (equal within an acceptable error range). The second screen layer 142 is formed with a plurality of second screen holes 1421 which are densely arranged and have equal aperture (equal within an acceptable error range). The aperture of the first screen holes 1411 is greater than the aperture of the second screen holes 1421. In the embodiment, in the first screen layer 141 and the second screen layer 142, except for the screen holes located in the edge region, the rest of the first screen holes 1411 and the second screen holes 1421 are substantially rectangular.

[0030] In the embodiment, the first screen assembly 10 further comprises a first driving mechanism (not shown in the figure) which is electrically connected to the controller 40. The first driving mechanism is electrically connected to and controlled by the controller 40, and is used to drive the first screen layer 141 and the second screen layer 142 to move, so as to switch different screen layers (the first screen layer 141 or the second screen layer 142) to the movement path of the particles 200 at different times.

[0031] In at least one embodiment of the present application, the first driving mechanism can be used to drive the first screen layer 141 and the second screen layer 142 to rotate, so that one of the first screen layer 141 and the second screen layer 142 rotates into the first detection space 111 and is located on the falling path of the particles 200, and the other rotates out of the first detection space 111. In at least one embodiment of the present application, the first driving mechanism can also be used to drive the first screen layer 141 and the second screen layer 142 to unfold or fold up. For example, the first screen layer 141 is driven to unfold to be located on the falling path of the particles 200, and the second screen layer 142 is driven to fold up and closely adhere to the inner wall of the first main body 11 to avoid the falling particles 200.

[0032] In the embodiment, in order to fully show the structure of the first screen 14, Figure 2 The figure shows the state that the first screen layer 141 and the second screen layer 142 are both located in the first detection space 111. In the actual working process of the particle size distribution detection device 100, only one screen layer is located on the falling path of the particles 200 at the same time.

[0033] In the embodiment, the controller 40 controls the first driving mechanism to drive the screen layer with the mesh aperture closer to and equal to or greater than the larger boundary value D2 of the target particle size range D1-D2 to the movement path of the particles 200 to be measured. For example, the first mesh 1411 has a mesh aperture N11 (e.g., 125 μm), and the second mesh 1421 has a mesh aperture N12 (e.g., 106 μm). If N11>N12≥D2, it is known that the mesh aperture N12 of the second mesh 1421 of the second screen layer 142 is greater than the larger boundary value D2 of the target particle size range, and the mesh aperture N12 is closer to the larger boundary value D2 than the mesh aperture N11 of the first mesh 1411. At this time, the controller 40 controls the first driving mechanism to drive the second screen layer 142 to the movement path of the particles 200 to be measured, so that the particles 200 to be measured with a particle size less than N2 are sieved out and continue to fall into the second vibration screen assembly 20, and the particles 200 to be measured with a particle size greater than N2 are retained on the second screen layer 142 and do not continue to participate in subsequent detection.

[0034] In other embodiments of the present application, the first screen 14 can include only a single screen layer or more screen layers. In the embodiment in which the first screen 14 includes more screen layers, the mesh apertures of the screen layers are different from each other. In other embodiments of the present application, the mesh can have other shapes.

[0035] In the embodiment, the first vibration screen assembly 10 further includes a first funnel structure 15 connected to the first main body 11. The first funnel structure 15 is located on the side of the first optical structure 12 away from the first screen 14. The first funnel structure 15 includes a first funnel 151 and a first closure 152. The first funnel 151 has a first opening 1511 facing the first tray 13, and the first closure 152 is connected to the first opening 1511 of the first funnel 151 in an openable and closable manner.

[0036] The first funnel 151 is used for temporarily storing the particles 200 to be detected before optical detection. The first closure 152 is controlled by the controller 40 and is used for closing or opening the first opening 1511. When the first closure 152 closes the first opening 1511, the particles 200 to be detected in the first funnel 151 are blocked from entering the first detection space 111. When the first closure 152 opens the first opening 1511, the particles 200 to be detected in the first funnel 151 fall into the first detection space 111 under the action of gravity. In the embodiment, the first closure 152 is controlled by the controller 40 and is also used for controlling the opening degree of the first opening 1511 to adjust the speed of the particles 200 to be detected entering the first detection space 111. When the speed of the particles 200 to be detected entering the first detection space 111 is low, the optical detection time is long, but the detection accuracy is improved. When the speed of the particles 200 to be detected entering the first detection space 111 is high, the optical detection speed is fast. The controller 40 can adjust the speed of the particles 200 to be detected entering the first detection space 111 according to one or any combination of the particle size of the particles 200 to be detected, the wavelength of the first laser, the power of the first laser, and the parameters of the first detection element 132.

[0037] The second vibration screen assembly 20 includes a second main body 21, a second optical structure 22, a second tray 23, a second screen 24, and a second funnel structure 25. The second main body 21 forms a cylindrical second detection space 211. The second optical structure 22 includes a plurality of second light emitting elements 221 and a plurality of second detection elements 222. The second funnel structure 25 includes a second funnel 251 and a second closure 252. The second optical structure 22, the second tray 23, and the second funnel structure 25 have substantially the same structure and function as the first optical structure 12, the first tray 13, and the first funnel structure 15.

[0038] The second screen 24 includes a third screen layer 241 and a fourth screen layer 242. The third screen layer 241 forms a plurality of third mesh holes 2411, and the fourth screen layer 242 forms a plurality of fourth mesh holes 2421. The diameters of the third mesh holes 2411, the fourth mesh holes 2421, the first mesh holes 1411, and the second mesh holes 1421 are different from each other. The second vibration screen assembly 20 further includes a second driving mechanism (not shown in the figure) for driving the third screen layer 241 and the fourth screen layer 242 to move.

[0039] The second vibration screen assembly 20 performs optical detection on the particles 200 to be detected entering the second detection space 211 through the second optical structure 22 to output a second detection signal. The second tray 23 is used for weighing the particles 200 to be detected after optical detection by the second optical structure 22 to output a second mass.

[0040] The third vibration screening assembly 30 comprises a third main body 31, a third optical structure 32, a third tray receiver 33, a third screen 34, and a third funnel structure 35. The third main body 31 forms a third detection space 311 in a cylindrical shape. The third optical structure 32 comprises a plurality of third light emitting elements 321 and a plurality of third detecting elements 322. The third funnel structure 35 comprises a third funnel 351 and a third closing element 352. The third optical structure 32, the third tray receiver 33, and the third funnel structure 35 are substantially identical in structure and function to the first optical structure 12, the first tray receiver 13, and the first funnel structure 15.

[0041] The third screen 34 comprises a fifth screen layer 341 and a sixth screen layer 342. The fifth screen layer 341 forms a plurality of fifth screen holes 3411, and the sixth screen layer 342 forms a plurality of sixth screen holes 3421. The fifth screen holes 3411, the sixth screen holes 3421, the first screen holes 1411, the second screen holes 1421, the third screen holes 2411, and the fourth screen holes 2421 are different in size. The third vibration screening assembly 30 further comprises a third driving mechanism (not shown in the figure) for driving the fifth screen layer 341 and the sixth screen layer 342 to move. In the present embodiment, the controller 40 controls the second driving mechanism to drive the screen layer, the screen holes of which are closest to and smaller than or equal to the smaller boundary value D1 of the target particle size range D1-D2, to move along the path of the to-be-detected particles 200.

[0042] The third vibration screening assembly 30 performs optical detection on the to-be-detected particles 200 entering the third detection space 311 through the third optical structure 32 to output a third detection signal. The third tray receiver 33 is used to weigh the to-be-detected particles 200 after the optical detection by the third optical structure 32 to output a third mass. In other embodiments of the present application, the vibration screening assembly at the bottom layer (for example, the third vibration screening assembly 30 in the present embodiment) can not comprise a screen.

[0043] In the present embodiment, the controller 40 is electrically connected to the first light emitting elements 121, the first detecting elements 122, the first tray receiver 13, the first driving mechanism, the first closing element 152, the second light emitting elements 221, the second detecting elements 222, the second tray receiver 23, the second driving mechanism, the second closing element 252, the third light emitting elements 321, the third detecting elements 322, the third tray receiver 33, the third driving mechanism, and the third closing element 352, respectively.

[0044] The controller 40 is configured to acquire the light intensity angle distribution of the first probe light according to the first probe signal, acquire the light intensity angle distribution of the second probe light according to the second probe signal, acquire the light intensity angle distribution of the third probe light according to the third probe signal, and acquire the particle size-volume distribution information of the part of the particles 200 with the particle size in the target particle size range based on the normal distribution curve and the first mass, the second mass and the third mass output by the first vibration screen assembly 10, the second vibration screen assembly 20 and the third vibration screen assembly 30 in sequence.

[0045] In at least one modified embodiment of the present application, when one of the boundary values of the preset particle size range is close to the peak value of the particle size range of all the particles 200 in a sample, the particle size distribution detection device 100 can accurately acquire the particle size-volume distribution information of the particles in the preset particle size range through the first vibration screen assembly 10 and the second vibration screen assembly 20. In this modified embodiment, the controller 40 is configured to acquire the light intensity angle distribution of the first probe light according to the first probe signal, acquire the light intensity angle distribution of the second probe light according to the second probe signal, and acquire the particle size-volume distribution information of the part of the particles 200 with the particle size in the target particle size range based on the normal distribution curve and the first mass and the second mass.

[0046] The present application also provides a particle size distribution detection method applied to the particle size distribution detection device 100.

[0047] Please refer to Figure 3 The particle size distribution detection method comprises the following steps.

[0048] In step S1, the particles to be measured are controlled to enter the first detection space.

[0049] In step S2, the first laser is emitted, and the first probe light scattered by the particles to be measured according to the first laser is received to generate a first probe signal. The light intensity angle distribution of the first probe light is acquired according to the first probe signal, and the first mass of the particles to be measured is weighed.

[0050] In step S3, part of the particles to be measured are controlled to enter the second detection space, and the particle size of the part of the particles to be measured is smaller than that of the remaining particles to be measured.

[0051] Step S4, emitting a second laser and receiving a second probe light scattered by the part of the particles to be measured according to the second laser to generate a second probe signal, obtaining an intensity-angle distribution of the second probe light according to the second probe signal, and weighing a second mass of the part of the particles to be measured; and

[0052] Step S5, obtaining a "particle size-volume" distribution information of at least part of the particles to be measured according to the intensity-angle distribution, the first mass, and the second mass based on a normal distribution curve.

[0053] In the use process of the particle size distribution detection device 100, the device is placed on a work plane (for example, a ground or a table top) in the orientation shown in the figure. In step S1, the particles to be measured 200 are placed in the first funnel 151 of the first vibration screen assembly 10 for temporary storage. The controller 40 controls the first closure 152 to keep the first opening 1511 of the first funnel 151 completely closed to prevent the particles to be measured 200 from falling into the first detection space 111. Figure 1

[0054] In step S2, the detection process is started. The controller 40 controls the first closure 152 to open the first opening 1511 and keep the first opening 1511 at a specific opening degree according to a preset speed, so that the speed of the particles to be measured 200 entering the first detection space 111 is basically constant during the whole optical detection process. At the same time, the controller 40 drives each first light emitting element 121 to emit a first laser. The particles to be measured 200 entering the first detection space 111 are scattered by the first laser when they are irradiated by the first laser. The controller 40 continuously receives the first probe signals generated by each first probe element 122 according to the received first probe light.

[0055] In step S2, the particles to be measured 200 after the optical detection fall onto the first tray collector 13 in sequence. When all the particles to be measured 200 fall onto the first tray collector 13, the first tray collector 13 weighs all the particles to be measured to obtain the total mass of the particles to be measured 200, that is, the first mass. The controller 40 controls the first driving mechanism to drive the first screen layer 141 or the second screen layer 142 in the first screen 14 to the path of the particles to be measured 200, and after the weighing of the first tray collector 13 is completed, the controller 40 controls the first tray collector 13 to be opened, so that the particles to be measured 200 in the first tray collector 13 continue to fall into the corresponding screen layer of the first screen 14.

[0056] In step S3, part of the particles to be measured 200 are screened out by the first screen 14 and continue to fall into the second funnel 251 of the second vibration screen assembly 20 for temporary storage, and the remaining part of the particles to be measured 200 remain on the first screen 14.

[0057] ​In step S4, the controller 40 controls the second vibrating sieve assembly 20 to sequentially perform optical and weight detection on the particles 200 to be tested falling into the second funnel 251, obtaining a second detection signal and a second weight, as detailed in step S2. After optical and weight detection by the second vibrating sieve assembly 20, some of the particles 200 to be tested in the second funnel 251 are sieved out by the second screen 24 and fall into the third funnel 351 of the third vibrating sieve assembly 30, while the remainder remains on the second screen 14. The particles 200 to be tested falling into the third funnel 351 undergo optical and weight detection by the third vibrating sieve assembly 30, obtaining a third detection signal and a third weight, as detailed in step S2.

[0058] The optical detection process of each of the aforementioned vibrating sieve components employs laser diffraction, which utilizes the volume equivalent sphere method. The particle 200 to be tested uses air as the dispersion medium. The intensity of the detection signal obtained by the detection element from the scattered detection light of the particle 200 reflects the intensity of the detection light. The detection signals generated by all detection elements can then be used to reflect the angular distribution of the detection light. The intensity and angular distribution of the detection light are related to the particle size of the particle 200. Larger particle sizes result in smaller scattering angles and higher intensity of the detection light; conversely, smaller particle sizes result in larger scattering angles and lower intensity. Therefore, based on the detection signals output by each detection element during the optical detection process, the following can be obtained: Figure 4 The angle and intensity of the probe light are shown. According to the Mie scattering theory, the intensity of the scattered light (i.e., the aforementioned probe light) is directly proportional to the sixth power of the particle size of the particle 200 being tested, inversely proportional to the fourth power of the wavelength of the laser, and related to the refractive index and absorptivity of the particle 200 being tested, as well as the refractive index of the dispersion medium (air in this application).

[0059] Based on the above inference, in step S5, the controller 40 combines the normal distribution formula. The simulated particle size distribution formula fd(X) and equivalent volume fraction formula fV(X) are as follows:

[0060] .

[0061] The simulated fd(X) and fV(X) are non-standard normal distribution curves, where μ, σ, and K are unknowns, and K is related to the particle size distribution and volume percentage distribution of the particle 200 to be tested. In this embodiment, three equations are established based on the particle size distribution and volume percentage distribution of three vibrating screens to solve for the above three unknowns, thereby finally obtaining the particle size distribution formula fd(X).

[0062] For the first sieve-shaking assembly 10, the first optical structure 12 optically detects all the particles 200 to be measured, and the overall volume distribution V1 of all the particles 200 to be measured can be obtained. The first tray 13 weighs all the particles 200 to be measured, and the first mass M1 of all the particles 200 to be measured can be obtained. The particle size of all the particles 200 to be measured is between d min -d max .

[0063] For the second sieve-shaking assembly 20, the second optical structure 22 optically detects the particles 200 to be measured entering the second funnel 251, and the overall volume distribution V2 of the particles 200 to be measured entering the second funnel 251 can be obtained. The second tray 23 weighs the particles 200 to be measured entering the second funnel 251, and the second mass M2 of the particles 200 to be measured entering the second funnel 251 can be obtained. The particle size of the particles 200 to be measured entering the second funnel 251 is smaller than the mesh size (hereinafter referred to as d1) of the corresponding sieve layer in the first sieve 14.

[0064] For the third sieve-shaking assembly 30, the third optical structure 32 optically detects the particles 200 to be measured entering the third funnel 351, and the overall volume distribution V3 of the particles 200 to be measured entering the third funnel 351 can be obtained. The third tray 33 weighs the particles 200 to be measured entering the third funnel 351, and the third mass M3 of the particles 200 to be measured entering the third funnel 351 can be obtained. The particle size of the particles 200 to be measured entering the third funnel 351 is smaller than the mesh size (hereinafter referred to as d2) of the corresponding sieve layer in the second sieve 24.

[0065] Therefore, after the detection by the first sieve-shaking assembly 10, the second sieve-shaking assembly 20, and the third sieve-shaking assembly 30, the controller 40 can establish the following equations:

[0066] (1)

[0067] (2)

[0068] (3)

[0069] In this embodiment, by selecting the sieve layer matching the larger value of the target particle size range in the first sieve-shaking assembly 10, and selecting the sieve layer matching the smaller value of the target particle size range in the second sieve-shaking assembly 20, the particles to be measured remaining in the second sieve-shaking assembly 20 and not entering the third sieve-shaking assembly 30 are the particles to be measured with the particle size in the target particle size range. Therefore, the distribution of the particles to be measured with the particle size in the target particle size range can be obtained:

[0070] (4)

[0071] In other embodiments of the present application, the particle size distribution detection device 100 includes more sieve assemblies, and the following equations in Table 1 and Table 2 can be obtained:

[0072] Table 1

[0073]

[0074] Table 2

[0075]

[0076] Thus, the distribution of the particles to be measured in any target particle size range can be obtained:

[0077] wherein n≥1 and is a positive integer.

[0078] The following is an example. In at least one embodiment of the present application, the particle size range of all the particles to be measured 200 in a sample is 1-1000 μm, and the target particle size range received by the controller 40 is 20-40 μm. That is, in the at least one embodiment, the “particle size-volume” distribution of the part of the particles to be measured in the sample having the particle size in the range of 20-40 μm is mainly concerned.

[0079] All the particles to be measured 200 are first subjected to optical detection and weight detection by the first sieve assembly 10, and the overall “particle size-volume” normal distribution image as shown in FIG. 1 is obtained. Figure 5 According to the equation in Table 1, the following can be known: Figure 5 Figure 5 In the equation, the distribution of the particles to be measured 200 having the particle size near the peak value can be clearly seen, but the volume of the particles to be measured in the target particle size range far from the peak value is almost close to 0. It can be known that the accuracy of the analysis result according to only the detection result of the first sieve assembly 10 is low, and the farther the target particle size deviates from the peak value, the greater the error of the result obtained.

[0080] After the optical detection and weight detection by the first sieve assembly 10, the sieve layer having the mesh size most close to and greater than or equal to the larger boundary value (i.e., 40 μm) of the target particle size range 20-40 μm is selected to sieve the particles to be measured 200. For example, the sieve layer having the mesh size of 40 μm is selected to sieve the particles to be measured 200, and then the particles to be measured 200 having the particle size less than 40 μm among the particles to be measured 200 fall into the second sieve assembly 20 from the first sieve assembly 10, and the particles to be measured 200 having the particle size greater than 40 μm remain on the sieve layer.

[0081] The second sieve assembly 20 continues to perform optical detection and weight detection on the particles to be measured 200 having the particle size less than 40 μm, and the “particle size-volume” normal distribution image as shown in FIG. 2 is obtained. Figure 6 ​The "particle size-volume" distribution image is shown. The second screening of the particles 200 is performed by selecting the screen layer in the second vibration screening assembly 20 having a mesh size closest to and less than or equal to the smaller boundary value (i.e. 20 μιη) of the target particle size range 20-40 μιη. For example, the second screening of the particles 200 entering the second vibration screening assembly 20 is performed by selecting the screen layer having a mesh size of 20 μιη. In this case, the particles 200 having a particle size less than 20 μιη fall into the third vibration screening assembly 30 from the second vibration screening assembly 20, and the particles 200 having a particle size greater than 40 μιη and less than 40 μιη remain on the screen layer.

[0082] The laser scanning of the particles 200 having a particle size less than 40 μιη greatly increases the target particle size content in the simulated real state distribution curve, and the accuracy of the data read out is greatly increased. Further, the combination of the first and second vibration screening assemblies 10, 20 and the third vibration screening assembly 30 greatly increases the accuracy of the particle size-volume distribution. Figure 7 The 20 μιη or less particle size distribution curve (the result of the laser scanning of the third vibration screening assembly 30) is shown. The particle size distribution simulated real state curve of the particles 200 having a particle size between 20 μιη and 40 μιη is derived, as shown. Figure 8 The "particle size-volume" distribution information is shown. In this case, the accuracy of the calculation of the particle size-volume distribution is greatly increased.

[0083] In other embodiments of the present application, the particle size distribution detection device 100 can include a greater number of vibration screening assemblies. In the other embodiments, the particle size distribution detection device 100 can calculate the "particle size-volume" distribution information of the particles 200 having a particle size in a greater number of target particle size ranges.

[0084] For example, in at least one embodiment of the present application, the particle size distribution detection device 100 includes n vibration screening assemblies. The particle size distribution detection device 100 obtains the "particle size-volume" distribution information of the particles 200 having a particle size in a first target particle size range by the first to third (numbered from top to bottom) vibration screening assemblies, obtains the "particle size-volume" distribution information of the particles 200 having a particle size in a second target particle size range by the fourth to sixth vibration screening assemblies, and obtains the "particle size-volume" distribution information of the particles 200 having a particle size in an n target particle size range by the (n-2) to n vibration screening assemblies. That is, the n vibration screening assemblies are divided into groups of vibration screening assemblies arranged from top to bottom. Each group of vibration screening assemblies obtains the "particle size-volume" distribution information of the particles 200 having a particle size in a different target particle size range.

[0085] The particle size distribution detection device 100 and the particle size distribution detection method of the above-mentioned particles, the first vibrating screen assembly 10 includes a first optical structure 12, a first tray receiver 13 and a first screen 14, the first optical structure 12 is used for optical detection of the particles 200 to be measured to obtain a first detection signal, the first tray receiver 13 is used for weight detection of the particles 200 to be measured to obtain a first mass, and the first screen 14 and the second vibrating screen assembly 20 are used for screening the particle size of the particles 200 to be measured. Based on the normal distribution curve, the light intensity angle distribution, the first mass and the second mass, the “particle size-volume” distribution information of at least part of the particles 200 to be measured can be accurately obtained.

[0086] In addition, by arranging multiple layers of vibrating screen assemblies, based on the normal distribution curve, the “particle size-volume” distribution curve of the part of the particles 200 to be measured with the particle size in the target particle size range can be accurately fitted.

[0087] In addition, by arranging multiple layers of vibrating screen assemblies, based on the normal distribution curve, the “particle size-volume” distribution curve of the part of the particles 200 to be measured with the particle size in the target particle size range can be accurately fitted.

[0088] Further, by increasing the number of layers of vibrating screen assemblies, the “particle size-volume” distribution curves of the part of the particles 200 to be measured with the particle size in multiple target particle size ranges can be obtained by the single particle size distribution detection device 100 in a single detection.

[0089] Those skilled in the art should recognize that the above embodiments are only used to illustrate the present application, and are not used as a limitation of the present application. Any appropriate changes and variations made to the above embodiments within the spirit and principles of the present application fall within the scope of the present application.

Claims

1. A particle size distribution detection device, characterized in that, The application relates to a particle size analyzer, which comprises: a first vibrating screen assembly, which comprises a first main body, a first optical structure, a first tray, a first screen and a first driving mechanism, the first main body is enclosed to form a first detection space, the first optical structure, the first tray and the first screen are located in the first detection space and are connected to the first main body; the first optical structure is used for emitting first laser light to irradiate particles to be measured in the first detection space and is used for receiving first detection light scattered by the particles to be measured according to the first laser light to generate a first detection signal, the first tray is used for weighing a first mass of the particles to be measured, the first screen comprises at least two screen layers with different mesh sizes, the first driving mechanism is connected to the at least two screen layers respectively, and the first screen is used for screening part of the particles to be measured; a second vibrating screen assembly, which forms a second detection space, the second vibrating screen assembly and the first vibrating screen assembly are arranged in sequence along a preset direction, the second vibrating screen assembly is used for obtaining a second mass of the part of the particles to be measured passing through the first screen and is used for generating a second detection signal according to the part of the particles to be measured; and a controller, which is electrically connected to the first optical structure, the first tray, the second vibrating screen assembly and the first driving mechanism respectively, the controller is used for controlling the first driving mechanism to switch one of the screen layers with a mesh size closer to a boundary value D2 of a preset target particle size range D1-D2 and greater than or equal to the boundary value D2 to a path of the particles to be measured, wherein D1 2. The particle size distribution measuring apparatus for particles according to claim 1, wherein the first optical structure comprises a plurality of first light emitting elements and a plurality of first detection elements, the plurality of first light emitting elements and the plurality of first detection elements are staggered arranged on an inner wall of the first main body; the controller is electrically connected to the plurality of first light emitting elements and the plurality of first detection elements respectively, the controller is used for driving the plurality of first light emitting elements to emit the first laser light when the particles to be measured enter the first detection space and is used for receiving a first detection signal generated by the plurality of first detection elements sensing the first detection light.

3. The particle size distribution measuring apparatus for particles according to claim 1, wherein the first tray is located between the first optical structure and the first screen; the controller is used for controlling the first tray to be closed to weigh the particles to be measured after passing through the first optical structure and is used for controlling the first tray to be opened to make the particles to be measured fall into the first screen after the weighing is completed.

4. The particle size distribution measuring apparatus for particles according to claim 1, wherein The second vibrating screen assembly comprises a second screen mesh comprising at least two screen mesh layers having different mesh sizes, and a second driving mechanism connected to the at least two screen mesh layers and the controller respectively; The controller is configured to control the second driving mechanism to switch one of the screen mesh layers having a mesh size closer to and smaller than a boundary value D1 of the target particle size range to a path of the part of the particles to be measured according to the boundary value D1.

5. The particle size distribution measuring apparatus for particles according to claim 1, wherein The first vibrating screen assembly further comprises a first funnel structure located on a side of the first optical structure away from the first screen mesh, and configured to accommodate the particles to be measured.

6. The particle size distribution measuring apparatus for particles according to claim 5, wherein The first funnel structure comprises a first funnel having a first opening facing the first screen mesh, and a first closure located at the first opening. The controller is electrically connected to the first closure, and configured to control the first closure to close or open the first opening, and to control an opening degree of the first opening to control a speed of the particles to be measured entering the first detection space.

7. The particle size distribution measuring apparatus of any one of claims 1 to 6, wherein The particle size distribution detection device comprises a plurality of vibrating screen assemblies arranged in sequence along a preset direction, and each vibrating screen assembly is configured to sequentially obtain particle size-volume distribution information of the particles to be measured having particle sizes in different target particle size ranges.

8. A method for detecting a particle size distribution of particles, characterized by, The particle size distribution detection device according to any one of claims 1-7; The particle size distribution detection method comprises: controlling the particles to be measured to enter the first detection space; controlling the first laser to be emitted and the first detection signal generated by the first detection light scattered by the particles to be measured according to the first laser to be received, obtaining the light intensity-angle distribution of the first detection light according to the first detection signal, and weighing the first mass of the particles to be measured; controlling the first driving mechanism to switch one of the screen mesh layers having a mesh size closer to and greater than a boundary value D2 of the target particle size range D1-D2 to a path of the particles to be measured according to the boundary value D2, so as to control part of the particles to be measured to enter the second detection space, the part of the particles to be measured having a particle size smaller than that of the remaining particles to be measured; controlling the second laser to be emitted and the second detection signal generated by the second detection light scattered by the part of the particles to be measured according to the second laser to be received, obtaining the light intensity-angle distribution of the second detection light according to the second detection signal, and weighing the second mass of the part of the particles to be measured; and obtaining particle size-volume distribution information of the part of the particles to be measured having particle sizes in the target particle size range according to the light intensity-angle distribution, the first mass and the second mass based on a normal distribution curve.

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