Laser particle size analysis device capable of quickly focusing

Abstract

The utility model relates to a laser particle size analyzer, aims to solve the problems of large focusing difficulty, long time consumption, low accuracy and the like of the laser particle size analyzer, and provides a laser particle size analyzer capable of quickly focusing, which comprises a laser emitting system and a laser receiving system which are connected to 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 a plurality of 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] The utility model relates to a laser particle size analyzer, in particular to a laser particle size analyzer capable of fast focusing. Background Art

[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 a variety of measurement scenarios, including but not limited to boiler refurbishment in power plants, furnace optimization in refining and petrochemical applications, process safety of ventilation headers, and product quality control in ethylene production. Laser particle size analyzers are key equipment for monitoring flue gas turbines in refinery catalytic units. The long-term operation of flue gas turbines is directly related to the energy consumption and benefits of catalytic cracking units. Laser particle size analyzers are used to monitor the concentration and particle size of catalysts in flue gas to protect the normal operation of flue gas turbines. Therefore, ensuring the efficient and accurate installation of laser particle size analyzers so that they can perform their due working performance in a timely manner is the key to ensuring the reliability of detection data.

[0004] At present, in the installation process of laser particle size analyzers, the focus is usually adjusted by naked eye observation. The main problem of this method is that due to the presence of more floating particles and impurities in the air at the production site, and the interference of natural light, the observation light in the optical tube of the laser particle size analyzer is affected to a certain extent, resulting in focusing defects such as difficulty, long time consumption and low accuracy when focusing by naked eye observation; and the laser will cause certain damage to the operator's eyes during focusing, affecting the operator's personal health; furthermore, due to the large vibration of the device at the production site, it undoubtedly increases the difficulty of on-site focusing installation, resulting in low focusing efficiency and affecting production progress. Summary of the invention

[0005] The utility model aims to solve the problems of great difficulty, long time consumption and low focusing accuracy in focusing the existing laser particle size analyzer, and proposes a laser particle size analyzer capable of fast focusing.

[0006] In order to achieve the above purpose, the technical solution proposed by the utility model is:

[0007] A laser particle size analysis device capable of rapid focusing comprises a laser emitting system and a laser receiving system arranged on both sides of a flue gas duct, and the special features thereof are:

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

[0009] The scattering centering device includes a centering mounting disc fixed on the inner wall of the laser receiving cavity. On the side of the centering mounting disc away from the lens group, there is a laser receiver and at least three photodiodes located on the same circumference; the laser receiver is arranged at the center position of the centering mounting disc, and a plurality of adjusting grooves are radially arranged on the outer side wall of the centering mounting disc;

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

[0011] Further, when the central axis of the sliding groove and the focal point of the lens group are in the same plane, if the focal length of the lens group is set as X, then the length L of the sliding groove = X ± 15 cm.

[0012] Further, 4 photodiodes are evenly distributed on the centering mounting disc on the same circumference.

[0013] Further, the number of the adjusting grooves and the sliding grooves is the same as the number of the photodiodes, and the positions correspond to each other one by one.

[0014] The beneficial effects of the present utility model:

[0015] 【1】The structure of the laser particle size analysis device capable of quickly focusing in the present utility model is simple. Through the scattering centering device, the system focusing can be accurately completed. The plurality of photodiodes arranged can detect the transmission aperture of the lens group from multiple angles, ensure that the laser receiver is located on the optical axis of the lens group, improve the focusing accuracy, simplify the focusing process, save the focusing time, reduce the damage caused by the laser to the operator's body, and improve the safety performance of the device.

[0016] 【2】Through the mutual cooperation of a plurality of sliding grooves, adjusting grooves and adjusting screws in the present utility model, multi-angle adjustment of the centering mounting disc can be realized, so that the central axis of the centering mounting disc coincides with the central axis of the lens group, ensuring that each photodiode is located on the transmission optical path of the lens group, and guaranteeing the adjustment accuracy of the device and the focusing accuracy.

[0017] 【3】When 4 photodiodes are arranged in the present utility model to achieve focus adjustment, the focus adjustment efficiency can be effectively improved. The 4 photodiodes can quickly and accurately position the transmission optical path from different angles, greatly saving the focus time and improving the focus accuracy. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 is a schematic structural diagram of a laser particle size analysis device capable of quickly focusing according to the present utility model;

[0019] Figure 2 is a schematic structural diagram of the scattering centering device in the embodiment of the present utility model;

[0020] Figure 3 is a schematic structural diagram of the centering mounting plate in the embodiment of the present utility model;

[0021] Figure 4 is a distribution diagram of the positions of the photodiodes and the laser receiver on the centering mounting plate in the embodiment of the present utility model;

[0022] Figure 5 is a schematic optical path principle diagram of the alignment and adjustment method of a laser particle size analysis device capable of quickly focusing according to the present utility model;

[0023] REFERENCE SIGNS:

[0024] 1 - laser emission 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 - adjustment groove, 11 - sliding groove, 12 - adjustment screw. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0025] As Figure 1 shown, a laser particle size analysis device capable of quickly focusing includes a laser emission system 1 and a laser receiving system 3 oppositely arranged on both sides of the 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 close to the flue gas duct 2, and the scattering centering device 6 is arranged at the focal point on the side of the lens group 5 away from the flue gas duct 2 in the laser receiving cavity 4;

[0026] As Figures 2 to 4 shown, the scattering centering device 6 includes a centering mounting plate 7 fixed on the inner wall of the laser receiving cavity 4. On the side of the centering mounting plate 7 away from the lens group 5, a laser receiver 8 and 4 photodiodes 9 evenly distributed on the same circumference are arranged. The laser receiver 8 is arranged at the center position of the centering mounting plate 7. On the outer side wall of the centering mounting plate 7, 4 adjustment grooves 10 corresponding to the positions of the 4 photodiodes 9 are radially arranged, and internal threads are arranged in the adjustment grooves 10;

[0027] On the outer wall of the laser receiving cavity 4, there are 4 sliding grooves 11 arranged axially along its axis, corresponding to the 4 adjusting grooves 10 one by one. The radial plane at the focal point of the lens group 5 is located within the corresponding radial plane of the sliding groove 11. Each sliding groove 11 is connected to the adjusting groove 10 through an adjusting screw 12. By changing the depth of the adjusting screw 12 screwed into the adjusting groove 10, the centering position of the centering mounting plate 7 is adjusted. By changing the position of the adjusting screw 12 on the sliding groove 11, the axial position of the centering mounting plate 7 is adjusted, so that the laser receiver 8 thereon coincides with the focal point of the lens group 5.

[0028] Among them, the 4 photodiodes 9 are exactly located at the four azimuths of the light path aperture of the transmitted light of the lens group 5. By observing the lighting conditions of the 4 photodiodes 9 and adjusting the centering mounting plate 7 in four azimuths through the adjusting screw 12, the central axis of the centering mounting plate 7 can be quickly made to coincide with the optical axis of the lens group 5, effectively shortening the focusing adjustment time of the system and improving the focusing efficiency.

[0029] When the central axis of the sliding groove 11 and the focal point of the lens group 5 are in the same plane, if the focal length of the lens group 5 is set as X, then the length L of the sliding groove 11 = X ± 15 cm.

[0030] Meanwhile, this embodiment also proposes an alignment and adjustment method for the above analysis device, including the following steps:

[0031] S1. Emitting laser into the laser receiving system 3 through the laser emitting system 1;

[0032] S2. Observing the lighting conditions of the photodiodes 9 on the centering mounting plate 7 in the laser receiving system 3. As shown, when each photodiode 9 is located on the light path formed after the laser passes through the lens group 5, all the set photodiodes 9 are lit, then step S3 is carried out; if not all lit, it means that not all the photodiodes 9 are located on the light path formed after the laser passes through the lens group 5. The centering mounting plate 7 is adjusted through the adjusting screw 12 so that all the photodiodes 9 are located on the light path formed after the laser passes through the lens group 5 until all the set 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; Figure 5

[0033] S3. Making the centering mounting plate 7 translate forward and backward along the axial direction on the sliding groove 11. During the forward and backward translation, collecting the output values of the laser receiver 8 at different positions when the photodiodes 9 are extinguished simultaneously. When the output value of the laser receiver 8 is the largest, this position is the focal point of the lens group 5, thus completing the focusing of the laser particle size analysis device.

[0034] Step S3 is specifically as follows: Place the centering mounting disk 7 at the foremost side of the sliding groove 11, and translate the centering mounting disk 7 backward along the axial direction; during the backward translation process, collect the output values of the laser receivers 8 at different positions after the photodiodes 9 are simultaneously extinguished. When the output value of the laser receiver 8 is the largest, this position is the focal point of the lens group 5, thereby completing the focusing of the laser particle size analysis device.

[0035] Alternatively, place the centering mounting disk 7 at the rearmost side of the sliding groove 11, and translate the centering mounting disk 7 forward along the axial direction; during the forward translation process, collect the output values of the laser receivers 8 at different positions after the photodiodes 9 are simultaneously extinguished. When the output value of the laser receiver 8 is the largest, this position is the focal point of the lens group 5, thereby completing the focusing of the laser particle size analysis device.

Claims

1. A laser particle size analysis device capable of rapid focusing, comprising a laser emitting system (1) and a laser receiving system (3) arranged on opposite sides of a flue gas duct (2), characterized in that: The laser receiving system (3) comprises a coaxially arranged laser receiving cavity (4), a lens group (5) and a scattering centering device (6); the lens group (5) is arranged at one end of the laser receiving cavity (4) close to the flue gas duct (2), and the scattering centering device (6) is arranged at a focal point of the lens group (5) in the laser receiving cavity (4) on a side away from the flue gas duct (2); The scattering centering device (6) comprises 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 arranged at the center position of the centering mounting plate (7), and a plurality of adjustment grooves (10) are radially arranged on the outer side wall of the centering mounting plate (7); A plurality of axial slide grooves (11) are provided along the circumference of the outer wall of the laser receiving cavity (4); a radial plane at the focal point of the lens group (5) is located within a radial plane corresponding to the slide groove (11); each slide groove (11) is connected to the adjustment groove (10) via an adjustment screw (12); the centering position of the centering mounting plate (7) is adjusted by changing the depth of each adjustment screw (12) screwed into the adjustment groove (10), so that the central optical axis of the laser receiver (8) and the lens group (5) coincide with each other; and the axial position of the centering mounting plate (7) is adjusted by changing the position of each adjustment screw (12) on the slide groove (11), so that the focal point of the laser receiver (8) and the lens group (5) coincide with each other.

2. A laser particle size analysis device capable of rapid focusing according to claim 1, characterized in that: When the central axis of the slide groove (11) and the focus of the lens group (5) are located in the same plane, the focal length of the lens group (5) is set to X, and the length of the slide groove (11) is L=X±15 cm.

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

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

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