Particle scattered light signal acquisition system

Abstract

The utility model relates to a particle scattered light signal acquisition system which 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 the photoelectric detector is used for collecting optical signals, an optical path for collecting the optical signals by using the camera is added, the minimum detection radius of the camera detector can reach 30 microns or even smaller, and 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, so that the particle detection upper limit is improved.

Description

Technical Field

[0001] The utility model relates to the technical field of particle measurement, in particular to a particle scattered light signal acquisition system. Background Art

[0002] Current laser particle size analyzers typically use photodetectors to collect scattered light signals. These detectors are either rings of detectors carved into silicon wafers or processed into independent, small detectors. When light strikes particles, it generates scattered light at various angles. This scattered light, striking the detectors, generates an electromotive force and current. Circuitry converts this current into a digital signal, the scattered light signal, which can be used to calculate particle size distribution and concentration in two-phase flow. This method is limited by machining accuracy, cost, and installation precision. The radius of the innermost ring detector is typically around 90μm. As the radius decreases, the required process technology and cost increase exponentially. Utility Model Content

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

[0004] To achieve the above objectives, 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, beam splitter, particle injector and lens are arranged in sequence from left to right at the front end of the laser, and the camera is set on the upper end of the beam splitter;

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

[0008] The preferred embodiment of the particle scattered light signal acquisition system is that the photoelectric detector and 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 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 collecting particle scattered light signals 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. Each circle is 1-N detectors, corresponding to different scattering angles.

[0013] Step 3: Calculate the sum of the pixels on each ring to obtain 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 sample addition, 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: Fusion 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 for 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 the ring detectors are seamlessly connected without losing scattered light information.

[0023] Beneficial effects

[0024] This utility model uses a camera as a detector to collect small-angle scattered light signals, and a photoelectric detector to collect large-angle scattered light signals. By using a camera as a detector, the minimum detector radius can be reduced to 30μm or even smaller. While maintaining the same lens focal length, the intensity of scattered light at smaller angles can be detected, thus increasing the upper limit of the laser particle size analyzer's measurement capability.

[0025] Camera detection does not require alignment of the light path. The focal center of the light path can be automatically calculated through digital image processing technology, and the relative position of each detector is calculated based on this point, thereby obtaining 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 for free setting of the detector radius and number, making it more adaptable. BRIEF DESCRIPTION OF THE DRAWINGS

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

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

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

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

[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 with reference to the following embodiments. It is obvious that the embodiments described are only a portion of the embodiments of the present invention, not all of them. All other embodiments derived by persons of ordinary skill in the art based on the embodiments of the present invention without creative effort are also within the scope of protection of the present invention.

[0033] Please see the 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 set 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. The dichroic prism 2 is placed in the transmission direction. Part of the light passes through the dichroic prism 2 and is collected by the photodetector 1, and part of the light is reflected by the dichroic 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 through the beam splitter prism 2.

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

[0038] A method for collecting particle scattered light signals 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. Each circle is 1-N detectors, corresponding to different scattering angles.

[0041] Step 3: Calculate the sum of the pixels on each ring to obtain 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 sample addition, 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: Fusion 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 the need to center 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 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 Shown is 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, those skilled in the art can still modify the technical solutions described in the aforementioned embodiments, or 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 scope of protection of the present invention.

Claims

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

2. The 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 that can be received by the photoelectric detector and the camera through the beam splitter prism.

3. The 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 can be received by the photodetector and the camera.

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