Laser particle size analysis device capable of quickly focusing and assembling and adjusting method of laser particle size analysis device

Abstract

The invention relates to a laser particle size analyzer, and provides a laser particle size analyzer capable of quickly focusing and an adjustment method of the laser particle size analyzer in order to solve the problems that an existing laser particle size analyzer is large in focusing difficulty, long in consumed time, low in accuracy rate and the like, and the laser particle size analyzer comprises a laser emitting system and a laser receiving system which are connected to the two ends of a flue gas pipeline. The laser receiving system comprises a laser receiving cavity, a lens group and a scattering centering device which are coaxially arranged; the scattering centering device is arranged in the laser receiving cavity and close to the focal point of the lens group; the scattering centering device comprises a centering mounting disc, a laser receiver and at least three photodiodes; an adjusting groove is formed in the outer side wall of the centering installation disc in the radial direction. A sliding groove is formed in the outer wall of the laser receiving cavity in the axial direction of the laser receiving cavity, the plane of the focal point of the lens set is located in the covering plane of the sliding groove, the sliding groove and the adjusting groove are connected through an adjusting screw, and the centering position of the centering installation disc is adjusted by changing the position of the adjusting screw on the sliding groove, so that the laser receiver on the centering installation disc coincides with the focal point of the lens set.

Description

Technical Field

[0001] This invention relates to laser particle size analyzers, and more specifically to a laser particle size analyzer with rapid focusing capability and its assembly and adjustment method. Background Technology

[0002] Laser particle size analyzers are mainly used in industrial production processes such as petrochemicals, power plants, and metallurgy. They can detect and analyze particulate matter in industrial production processes, making it easier for production personnel to obtain relevant detection information.

[0003] Laser particle size analyzers provide valuable measurement data for combustion control, process quality, safety, and environmental applications. They can be used in various measurement scenarios, including but not limited to boiler overhaul in power plants, furnace optimization in oil refining and petrochemical applications, process safety in ventilation manifolds, and product quality control in ethylene production. As a key device in refinery catalytic cracking units for monitoring flue gas turbines, and given that the long-term operation of these turbines directly affects the energy consumption and efficiency of the catalytic cracking unit, laser particle size analyzers monitor the concentration and particle size of catalysts in the flue gas to protect the normal operation of the turbines. Therefore, ensuring the efficient and accurate installation of the laser particle size analyzer, enabling it to perform its intended function in a timely manner, is crucial to guaranteeing the reliability of the detection data.

[0004] Currently, the installation process of laser particle size analyzers typically involves visual focusing. However, this method suffers from several drawbacks. The presence of numerous floating particles and impurities in the air at the production site, coupled with interference from natural light, affects the light source in the laser particle size analyzer's optical tube. This results in focusing difficulties, time-consuming processes, and low accuracy. Furthermore, the laser can cause eye damage to operators during focusing, impacting their health. Additionally, the significant vibrations of the equipment at the production site further complicate on-site focusing, leading to lower focusing efficiency and impacting production progress. Summary of the Invention

[0005] The purpose of this invention is to solve the problems of high difficulty, long time consumption and low focusing accuracy in existing laser particle size analyzers, and to propose a laser particle size analyzer and its assembly and adjustment method that can focus quickly.

[0006] To achieve the above objectives, the technical solution proposed by this invention is as follows:

[0007] A laser particle size analyzer with rapid focusing capability includes a laser emitting system and a laser receiving system positioned opposite each other on both sides of a flue gas duct. Its key feature is that:

[0008] The laser receiving system includes a coaxially arranged laser receiving cavity, a lens group, and a scattering centering device; the lens group is located at one end of the laser receiving cavity near the flue gas duct, and the scattering centering device is located at the focal point of the lens group on the side of the laser receiving cavity away from the flue gas duct.

[0009] The scattering centering device includes a centering mounting plate fixed on the inner wall of the laser receiving cavity. A laser receiver and at least three photodiodes located on the same circumference are arranged on the side of the centering mounting plate away from the lens group. The laser receiver is located at the center of the centering mounting plate, and multiple adjustment grooves are radially arranged on the outer wall of the centering mounting plate.

[0010] Multiple axial grooves are formed along the circumference of the outer wall of the laser receiving cavity. The radial plane at the focal point of the lens group is located in the radial plane corresponding to the groove. The groove and the adjustment groove are connected by adjusting screws. The centering position of the centering mounting plate is adjusted by changing the depth of each adjusting screw into the adjustment groove, so that the laser receiver coincides with the central optical axis of the lens group. The axial position of the centering mounting plate is adjusted by changing the position of each adjusting screw on the groove, so that the focal point of the laser receiver coincides with the focal point of the lens group.

[0011] Furthermore, when the central axis of the slide and the focal point of the lens group are located on the same plane, and the focal length of the lens group is set to X, then the length of the slide L = X ± 15 cm.

[0012] Furthermore, the centering mounting plate has four photodiodes evenly distributed on the same circumference.

[0013] Furthermore, the number of adjustment slots and slides is the same as the number of photodiodes, and their positions correspond one-to-one.

[0014] Furthermore, this invention also proposes a method for assembling and adjusting the aforementioned laser particle size analysis device capable of rapid focusing, characterized by the following steps:

[0015] S1. Emit laser light to laser receiving system through laser emission system;

[0016] S2. Observe the lighting status of each photodiode on the centering mounting plate in the laser receiving system. If all the set photodiodes are lit, proceed to step S3; if not all of them are lit, adjust the centering mounting plate by adjusting the screws until all the set photodiodes are lit.

[0017] S3. Move the centering mounting plate along the axial direction on the slide. During the translation process, collect the output value of the laser receiver at different positions when the photodiodes are turned off at the same time. When the output value of the laser receiver is the maximum, the position is the focal point of the lens group, thus completing the focusing of the laser particle size analyzer.

[0018] Furthermore, step S3 specifically includes:

[0019] Position the centering mounting plate at one end of the slide groove closer to or further away from the lens group, and then move the centering mounting plate axially towards the other end of the slide groove. During the translation process, collect the output values ​​of the laser receiver at different positions after the photodiodes are simultaneously turned off. When the output value of the laser receiver is at its maximum, that position is the focal point of the lens group, thus completing the focusing of the laser particle size analyzer.

[0020] The beneficial effects of this invention are:

[0021] [1] The laser particle size analysis device with fast focusing of the present invention has a simple structure. The system can be accurately focused by the scattering centering device. The multiple photodiodes set therein can detect the transmission aperture of the lens group from multiple angles to ensure that the laser receiver is located on the optical axis of the lens group, which improves the accuracy of focusing, simplifies the focusing process, saves focusing time, reduces the damage to the operator's body caused by the laser, and improves the safety performance of the device.

[0022] [2] The present invention can achieve multi-angle adjustment of the centering mounting plate by means of the cooperation of multiple sliding grooves, adjustment grooves and adjustment screws, so that the central axis of the centering mounting plate coincides with the central axis of the lens group, ensuring that each photodiode is located in the transmission light path of the lens group, thus ensuring the adjustment accuracy and focusing accuracy of the device.

[0023] [3] In this invention, setting four photodiodes to achieve focus adjustment can effectively improve the focus adjustment efficiency. The four photodiodes can quickly and accurately position the transmission light path from different angles, which greatly saves the focusing time and improves the focusing accuracy.

[0024] [4] The focusing method of the laser particle size analysis device with rapid focusing of the present invention has simple operation steps and is easy to implement. By moving the centering mounting plate forward or backward along the axial direction on the slide, the output value of the laser receiver at different positions when the photodiode is turned off at the same time is collected, and the accurate position of the focus is determined. Its focusing efficiency is high, effectively saving the focusing time of the system, and avoiding the interference of external natural light on the system focusing, ensuring the focusing accuracy, realizing rapid focusing, and reducing the labor intensity of installation and focusing. Attached Figure Description

[0025] Figure 1 This is a schematic diagram of the structure of a laser particle size analysis device with rapid focusing according to the present invention;

[0026] Figure 2 This is a schematic diagram of the scattering centering device in an embodiment of the present invention;

[0027] Figure 3 This is a schematic diagram of the structure of the centering installation disk in an embodiment of the present invention;

[0028] Figure 4 This is a diagram showing the positional distribution of the photodiode and laser receiver on the mounting plate in an embodiment of the present invention.

[0029] Figure 5 This is a schematic diagram of the optical path principle of the assembly and adjustment method of the laser particle size analysis device with rapid focusing according to the present invention.

[0030] Figure label:

[0031] 1-Laser emitting system, 2-Flue gas duct, 3-Laser receiving system, 4-Laser receiving cavity, 5-Lens group, 6-Scattering centering device, 7-Centering mounting plate, 8-Laser receiver, 9-Photodiode, 10-Adjusting groove, 11-Slide groove, 12-Adjusting screw. Detailed Implementation

[0032] like Figure 1 As shown, a laser particle size analysis device with rapid focusing includes a laser emitting system 1 and a laser receiving system 3 arranged opposite to each other on both sides of a flue gas duct 2. The laser receiving system 3 includes a laser receiving cavity 4, a lens group 5, and a scattering centering device 6 arranged coaxially. The lens group 5 is arranged at one end of the laser receiving cavity 4 near the flue gas duct 2, and the scattering centering device 6 is arranged at the focal point of the lens group 5 on the side of the laser receiving cavity 4 away from the flue gas duct 2.

[0033] like Figures 2 to 4 As shown, the scattering centering device 6 includes a centering mounting plate 7 fixed on the inner wall of the laser receiving cavity 4. A laser receiver 8 and four photodiodes 9 evenly distributed on the same circumference are arranged on the side of the centering mounting plate 7 away from the lens group 5. The laser receiver 8 is located at the center of the centering mounting plate 7. Four adjustment grooves 10 are radially arranged on the outer wall of the centering mounting plate 7, corresponding one-to-one with the positions of the four photodiodes 9. The adjustment grooves 10 are provided with internal threads.

[0034] The outer wall of the laser receiving cavity 4 has four sliding grooves 11 that correspond one-to-one with the four adjustment grooves 10. The radial plane at the focal point of the lens group 5 is located in the corresponding radial plane of the sliding groove 11. Each sliding groove 11 is connected to the adjustment groove 10 by adjusting screws 12. The centering position of the centering mounting plate 7 is adjusted by changing the depth of the adjusting screws 12 into the adjustment groove 10. The axial position of the centering mounting plate 7 is adjusted by changing the position of the adjusting screws 12 on the sliding groove 11, so that the laser receiver 8 on it coincides with the focal point of the lens group 5.

[0035] The four photodiodes 9 are positioned precisely at the four positions of the aperture of the transmission optical path of the lens group 5. By observing the illumination of the four photodiodes 9, the centering mounting plate 7 can be adjusted in four positions by adjusting the screw 12. This allows the central axis of the centering mounting plate 7 to be quickly aligned with the optical axis of the lens group 5, effectively shortening the system's focusing adjustment time and improving focusing efficiency.

[0036] When the central axis of the slide groove 11 and the focal point of the lens group 5 are on the same plane, and the focal length of the lens group 5 is set to X, then the length L of the slide groove 11 is X ± 15 cm.

[0037] Furthermore, this embodiment also proposes a method for assembling and adjusting the above-mentioned analytical device, including the following steps:

[0038] S1. A laser is emitted from the laser emitting system 1 into the laser receiving system 3;

[0039] S2. Observe the lighting status of each photodiode 9 on the centering mounting plate 7 in the laser receiving system 3, such as... Figure 5 As shown, when each photodiode 9 is located on the optical path formed after the laser passes through the lens group 5, all the photodiodes 9 are lit, and step S3 is performed; if not all of them are lit, it means that not all of the photodiodes 9 are located on the optical path formed after the laser passes through the lens group 5. The centering mounting plate 7 is adjusted by adjusting the adjusting screw 12 so that all of the photodiodes 9 are located on the optical path formed after the laser passes through the lens group 5 until all of the photodiodes 9 are lit. Then the central axis of the centering mounting plate 7 coincides with the central optical axis of the lens group 5.

[0040] S3. Move the centering mounting plate 7 forward and backward along the axial direction on the slide groove 11. During the forward and backward translation process, collect the output value of the laser receiver 8 at different positions when the photodiode 9 is turned off at the same time. When the output value of the laser receiver 8 is the maximum, the position is the focal point of the lens group 5, thereby completing the focusing of the laser particle size analysis device.

[0041] Step S3 is as follows: Position the centering mounting plate 7 at the foremost side of the slide groove 11, and move the centering mounting plate 7 backward along the axial direction; during the backward movement, collect the output values ​​of the laser receiver 8 at different positions after the photodiode 9 is simultaneously turned off. When the output value of the laser receiver 8 is the largest, that position is the focal point of the lens group 5, thereby completing the focusing of the laser particle size analysis device.

[0042] Alternatively, the centering mounting plate 7 is positioned at the rear of the slide groove 11, and the centering mounting plate 7 is moved forward along the axial direction. During the forward movement, the output values ​​of the laser receiver 8 at different positions after the photodiodes 9 are simultaneously turned off are collected. When the output value of the laser receiver 8 is the maximum, that position is the focal point of the lens group 5, thereby completing the focusing of the laser particle size analyzer.

Claims

1. A laser particle size analysis device with rapid focusing capability, comprising a laser emitting system (1) and a laser receiving system (3) disposed opposite to each other on both sides of a flue gas duct (2), characterized in that: The laser receiving system (3) includes a laser receiving cavity (4), a lens group (5), and a scattering centering device (6) arranged coaxially; the lens group (5) is arranged at one end of the laser receiving cavity (4) near the flue gas pipe (2), and the scattering centering device (6) is arranged at the focal point of the lens group (5) on the side of the laser receiving cavity (4) away from the flue gas pipe (2); The scattering centering device (6) includes a centering mounting plate (7) fixed on the inner wall of the laser receiving cavity (4). A laser receiver (8) and at least three photodiodes (9) located on the same circumference are arranged on the side of the centering mounting plate (7) away from the lens group (5). The laser receiver (8) is located at the center of the centering mounting plate (7). A plurality of adjustment grooves (10) are radially arranged on the outer wall of the centering mounting plate (7). Multiple axial grooves (11) are provided on the outer wall of the laser receiving cavity (4) along the circumference. The radial plane at the focal point of the lens group (5) is located in the radial plane corresponding to the groove (11). Each groove (11) is connected to the adjustment groove (10) by adjusting screws (12). The centering position of the centering mounting plate (7) is adjusted by changing the depth of each adjusting screw (12) screwed into the adjustment groove (10), so that the laser receiver (8) coincides with the central optical axis of the lens group (5). The axial position of the centering mounting plate (7) is adjusted by changing the position of each adjusting screw (12) on the groove (11), so that the focal point of the laser receiver (8) coincides with the focal point of the lens group (5).

2. The laser particle size analysis device with rapid focusing capability according to claim 1, characterized in that: When the central axis of the slide (11) and the focal point of the lens group (5) are on the same plane, and the focal length of the lens group (5) is set to X, then the length L of the slide (11) is X ± 15 cm.

3. The laser particle size analysis device with rapid focusing capability according to claim 2, characterized in that: The centering mounting plate (7) has four photodiodes (9) evenly distributed on the same circumference.

4. The laser particle size analysis device with rapid focusing capability according to claim 3, characterized in that: The number of adjustment grooves (10) and slide grooves (11) is the same as the number of photodiodes (9), and their positions correspond one-to-one.

5. The assembly and adjustment method of the laser particle size analyzer with rapid focusing as described in any one of claims 1-4, characterized in that, Includes the following steps: S1. A laser is emitted from the laser emitting system (1) to the laser receiving system (3); S2. Observe the lighting status of each photodiode (9) on the centering mounting plate (7) in the laser receiving system (3). If all the set photodiodes (9) are lit, proceed to step S3. If they are not all lit, adjust the centering mounting plate (7) by adjusting the adjusting screw (12) until all the set photodiodes (9) are lit. S3. Move the centering mounting plate (7) along the axial direction on the slide (11). During the translation process, collect the output values ​​of the laser receiver (8) at different positions when the photodiode (9) is turned off at the same time. When the output value of the laser receiver (8) is the maximum, the position is the focal point of the lens group (5), thus completing the focusing of the laser particle size analysis device.

6. The assembly and adjustment method of the laser particle size analysis device with rapid focusing according to claim 5, characterized in that, Step S3 is as follows: Position the centering mounting plate (7) at one end of the slide groove (11) near the lens group (5) or away from the lens group (5), and move the centering mounting plate (7) to the other end of the slide groove (11) in the axial direction. During the translation process, the output values ​​of the laser receiver (8) at different positions are collected after the photodiode (9) is turned off simultaneously. When the output value of the laser receiver (8) is the maximum, that position is the focal point of the lens group (5), thus completing the focusing of the laser particle size analysis device.

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