Particle scattered light signal acquisition system and method thereof

Abstract

The invention relates to a particle scattered light signal acquisition system and method. The system comprises a photoelectric detector, a beam splitter prism, a camera, a particle sample injector, a lens and a laser. Light emitted by the laser irradiates the particle sample injector through the converging lens, the beam splitter prism is placed in the transmission direction, one part of light penetrates through the beam splitter prism and is collected by the photoelectric detector, and the other part of light is reflected by the beam splitter prism and is collected by the camera. When particles pass through the particle sample injector, scattered light is generated, one part of the scattered light is collected by the photoelectric detector, and the other part of the scattered light is collected by the camera. On the basis that a photoelectric detector is used for collecting optical signals, an optical path for collecting the optical signals through a camera is added, the minimum detection radius of a camera detector can reach 30 microns or even smaller, small-angle scattered light which cannot be collected by the photoelectric detector can be collected under the condition that the focal length of the lens is not changed, and then the particle detection upper limit is improved.

Description

Technical Field

[0001] The present invention relates to the technical field of particle measurement, and in particular to a particle scattered light signal acquisition system and method thereof. Background Art

[0002] At present, laser particle size analyzers usually use photoelectric detectors to collect scattered light signals, that is, detectors are engraved in rings on silicon wafers or silicon wafers are processed into independent small detectors. When light irradiates particles, scattered light will be generated at various angles. The scattered light irradiates the detector and generates electromotive force and current. The current is converted into digital signals, that is, scattered light signals, through circuits. These scattered light signals can be used to calculate the particle size distribution and concentration information of particles in two-phase flow. This method is limited by processing accuracy, cost and installation accuracy. Generally, the radius of the innermost ring detector can be about 90μm. As the radius decreases, the required process technology and cost will increase exponentially. Summary of the invention

[0003] The object of the present invention is to provide a particle scattered light signal acquisition system and method thereof to solve the problems raised in the above background technology.

[0004] In order to achieve the above-mentioned purpose, the present invention provides the following technical solutions:

[0005] A particle scattered light signal acquisition system includes a photodetector, a beam splitter, a camera, a particle injector, a lens and a laser;

[0006] The photoelectric detector, the beam splitter prism, the particle injector, and the lens are arranged in sequence from left to right at the front end of the laser, and the camera is arranged at the upper end of the beam splitter prism;

[0007] The light emitted by the laser is irradiated to the particle injector through a converging lens, and a beam splitter prism is placed in the transmission direction. Part of the light passes through the beam splitter prism and is collected by the photodetector, and part of the light is reflected by the beam splitter prism and collected by the camera. When particles pass through the particle injector, scattered light is generated, and part of the scattered light is collected by the photodetector, and part of the scattered light is collected by the camera.

[0008] The preferred embodiment of the particle scattered light signal acquisition system is that the photoelectric detector and the camera can be placed tilted or vertically, and the placement position and angle are set according to the light of the beam splitter prism that can be received by the photoelectric detector and the camera.

[0009] A preferred solution of the particle scattered light signal acquisition system is that the tilt angle of the beam splitter prism is set according to the light that can be received by the photoelectric detector and the camera.

[0010] A method for a particle scattered light signal acquisition system comprises the following steps:

[0011] Step 1: Find the focus of the laser in the image captured by the camera;

[0012] Step 2: Draw concentric circles with the focal center as the center, and each circle is 1-N detectors corresponding to different scattering angles;

[0013] Step 3: Calculate the sum of the pixels on each ring to get the light intensity value of the detector;

[0014] Step 4: Collect the background light intensity signal of the camera detector and the light intensity signal after adding the sample;

[0015] Step 5: Collect the background light intensity signal and incident light intensity signal of the photodetector, the light intensity signal after adding the sample, and the transmitted light intensity signal;

[0016] Step 6: Calculate the transmittance: transmittance = transmitted light intensity / incident light intensity;

[0017] Step 7: Calculate the scattered light signal of the sample:

[0018] Scattered light signal of camera detector = light intensity after sample addition – background light intensity × transmittance;

[0019] The scattered light signal of the photodetector = light intensity after sample addition – background light intensity × transmittance;

[0020] Step 8: Combine the scattered light signal of the camera detector and the scattered light signal of the photoelectric detector to obtain the scattered light intensity signal of the particle group.

[0021] The preferred solution of the method of applying a particle scattered light signal acquisition system is that in step 1, a camera detector is used without centering the light path, and the focal center of the light path is automatically calculated by digital image processing technology.

[0022] The preferred embodiment of the method of applying a particle scattered light signal acquisition system is that the radius and number of the rings can be freely set in step 2, and each ring detector is seamlessly connected without losing scattered light information.

[0023] Beneficial Effects

[0024] The present invention uses a camera as a detector to collect small-angle scattered light signals, and uses a photoelectric detector to collect large-angle scattered light signals. Since a camera is used as a detector, the minimum detector radius can reach 30 μm or even smaller. When the focal length of the lens remains unchanged, the scattered light intensity at a smaller angle can be received, so that the upper limit of the measurement of the laser particle size analyzer is larger.

[0025] There is no need to align the light path when using camera detection. The focal center of the light path can be automatically calculated through digital image processing technology, and the relative position of each detector can be calculated based on this point to obtain more accurate scattered light intensity information. In addition, the detectors are seamlessly connected and no scattered light information is lost.

[0026] The use of camera detectors allows the detector radius and number to be freely set, making it more adaptable. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] Figure 1 is a schematic diagram of a particle scattered light signal acquisition system;

[0028] Figure 2 The background image collected by the camera;

[0029] Figure 3 The sampled image collected by the camera;

[0030] Figure 4 is the sample scattered light intensity signal obtained.

[0031] In the figure: 1. Photodetector; 2. Beam splitter; 3. Camera; 4. Particle injector; 5. Lens; 6. Laser. DETAILED DESCRIPTION

[0032] The present invention will be described clearly and completely below in conjunction with the embodiments. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0033] Please see attached Figure 1-4 , a particle scattered light signal acquisition system, comprising a photodetector 1, a beam splitter prism 2, a camera 3, a particle injector 4, a lens 5, and a laser 6;

[0034] The photodetector 1, the beam splitter prism 2, the particle injector 4, and the lens 5 are arranged in sequence from left to right at the front end of the laser 6, and the camera 3 is arranged at the upper end of the beam splitter prism 2;

[0035] The light emitted by the laser 6 is irradiated to the particle injector 4 through the converging lens 5, and the beam splitter prism 2 is placed in the transmission direction. Part of the light passes through the beam splitter prism 2 and is collected by the photodetector 1, and part of the light is reflected by the beam splitter prism 2 and deviates from the incident direction to be collected by the camera 3.

[0036] The photoelectric detector 1 and the camera 3 can be placed tilted or vertically, and the placement position and angle are set according to the light that can be received by the photoelectric detector 1 and the camera 3 from the beam splitter prism 2 .

[0037] The tilt angle of the beam splitter prism 2 is set according to the light that the photodetector 1 and the camera 3 can receive.

[0038] A method for a particle scattered light signal acquisition system comprises the following steps:

[0039] Step 1: Find the focus of the laser in the image captured by the camera;

[0040] Step 2: Draw concentric circles with the focal center as the center, and each circle is 1-N detectors corresponding to different scattering angles;

[0041] Step 3: Calculate the sum of the pixels on each ring to get the light intensity value of the detector;

[0042] Step 4: Collect the background light intensity signal of the camera detector and the light intensity signal after adding the sample;

[0043] Step 5: Collect the background light intensity signal and incident light intensity signal of the photodetector, the light intensity signal after adding the sample, and the transmitted light intensity signal;

[0044] Step 6: Calculate the transmittance: transmittance = transmitted light intensity / incident light intensity;

[0045] Step 7: Calculate the scattered light signal of the sample:

[0046] Scattered light signal of camera detector = light intensity after sample addition – background light intensity × transmittance;

[0047] The scattered light signal of the photodetector = light intensity after sample addition – background light intensity × transmittance;

[0048] Step 8: Combine the scattered light signal of the camera detector and the scattered light signal of the photoelectric detector to obtain the scattered light intensity signal of the particle group.

[0049] In step 1, the camera detector is used without centering the light path, and the focal center of the light path is automatically calculated through digital image processing technology.

[0050] In step 2, the radius and number of the rings can be freely set, and the ring detectors are seamlessly connected without losing scattered light information.

[0051] Example 1

[0052] like Figure 2As shown, concentric circles are drawn with the center of the laser focus as the center, and the radii of the circles are: 27.627μm, 30.304μm, 33.241μm, 36.462μm, 39.995μm, 43.871μm, 48.122μm, 52.785μm, 57.900μm, 63.511μm, 69.665μm, 76.415μm, 83.820μm, 91.942μm, 100.852μm, 110.624μm, 121.344μm, 133.102μm, 145.999μm, 160.147μm, 175.665μm, 192.687μm, and 211.359μm. The area between every two rings is a detector, for a total of 22 detectors.

[0053] like Figure 2 The background image captured by the camera is shown. According to step 3, the light intensity values ​​on 1-22 detectors under the background state are calculated, that is, the background light intensity is collected.

[0054] like Figure 3 The image after sample addition is shown as captured by the camera. The light intensity values ​​on detectors 1 to 22 after sample addition are calculated according to step 3, that is, the light intensity after sample addition is collected.

[0055] like Figure 4 The figure shows the sample scattered light intensity signal obtained according to step six, step seven and step eight.

[0056] The inversion algorithm is used to solve the above scattered light intensity signal, and the obtained particle size distribution data is as follows:

[0057] Sample name D10 D50 D90 1500-2000 glass beads-1 1408 1796 2349 1500-2000 glass beads-2 1411 1801 2355 1500-2000 glass beads-3 1415 1809 2364 1500-2000 glass beads-4 1409 1799 2352 1500-2000 glass beads-5 1415 1809 2364

[0058] Although the present invention has been described in detail with reference to the aforementioned embodiments, it is still possible for those skilled in the art to modify the technical solutions described in the aforementioned embodiments, or to make equivalent substitutions for some of the technical features therein. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. A particle scattered light signal acquisition system, characterized in that: Includes photodetectors, beam splitters, cameras, particle injectors, lenses, and lasers; The photoelectric detector, the beam splitter prism, the particle injector, and the lens are arranged in sequence from left to right at the front end of the laser, and the camera is arranged at the upper end of the beam splitter prism; The light emitted by the laser is irradiated to the particle injector through the converging lens, and a beam splitter prism is placed in the transmission direction. The photoelectric detector receives the light transmitted by the beam splitter prism, and the camera detector receives the light reflected by the beam splitter prism. When particles pass through the particle injector, scattered light is generated, part of which is collected by the photoelectric detector and part by the camera.

2. A particle scattered light signal acquisition system according to claim 1, characterized in that: The photoelectric detector and the camera can be placed tilted or vertically, and the placement position and angle are set according to the light of the beam splitter prism that can be received by the photoelectric detector and the camera.

3. A particle scattered light signal acquisition system according to claim 1, characterized in that: The tilt angle of the beam splitter prism is set according to the light that the photodetector and the camera can receive.

4. The method for using a particle scattered light signal acquisition system according to claims 1-3, characterized in that: The following steps are involved: Step 1: Find the focus of the laser in the image captured by the camera; Step 2: Draw concentric circles with the focal center as the center, and each circle is 1-N detectors corresponding to different scattering angles; Step 3: Calculate the sum of the pixels on each ring to get the light intensity value of the detector; Step 4: Collect the background light intensity signal of the camera detector and the light intensity signal after adding the sample; Step 5: Collect the background light intensity signal and incident light intensity signal of the photodetector, the light intensity signal after adding the sample, and the transmitted light intensity signal; Step 6: Calculate the transmittance: transmittance = transmitted light intensity / incident light intensity; Step 7: Calculate the scattered light signal of the sample: Scattered light signal of camera detector = light intensity after sample addition – background light intensity × transmittance; The scattered light signal of the photodetector = light intensity after sample addition – background light intensity × transmittance; Step 8: Combine the scattered light signal of the camera detector and the scattered light signal of the photoelectric detector to obtain the scattered light intensity signal of the particle group.

5. The method of using a particle scattered light signal acquisition system according to claim 4, characterized in that: In step 1, the camera detector is used without centering the light path, and the focal center of the light path is automatically calculated through digital image processing technology.

6. The method of using a particle scattered light signal acquisition system according to claim 4, characterized in that: In step 2, the radius and number of the rings can be freely set, and the ring detectors are seamlessly connected without losing scattered light information.

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