Telemetering type laser-induced breakdown spectroscopy detection system

Abstract

The invention relates to a telemetering type laser-induced breakdown spectroscopy detection system which is characterized in that a light outlet of a laser is aligned with the position of a light guide arm base, a laser beam expanding device is mounted in the light guide arm base, and laser is expanded into parallel light through the laser beam expanding device and then sequentially passes through a first laser reflector, a second laser reflector, a third laser reflector and a dichroscope; and the fourth aluminum film reflecting mirror and the fused quartz glass are converged on the sample to be detected and are excited to generate plasmas. According to the principle of light path reversibility, the spectrum generated by the plasma can be changed into parallel light through the fused quartz lens, and the parallel light enters the optical fiber coupling module through the fourth aluminum film reflector and the dichroscope and is transmitted to the spectrum detector through the optical fiber. According to the invention, the high-temperature molten sample to be detected can be detected, the free adjustment of the light path in the spatial position is realized, and the problems of high temperature of the straight surface of the detection probe, difficulty in field installation and the like are solved.

Description

Technical Field

[0001] The invention relates to the technical field of laser induced breakdown spectroscopy detection, and more particularly to a detection device in a harsh on-site environment, where ordinary probes are difficult to install, and in a high temperature or dusty environment. Background Art

[0002] In the metallurgical industry, metallurgical melts need to be tested for composition when they come out of the furnace in order to determine whether the current product is qualified and whether it is consistent with the subsequent process technology, and to guide the setting of relevant material ratios. Laser induced breakdown spectroscopy (LIBS) is often used in component testing. This technology uses ultrashort pulse lasers to focus on the sample surface to form plasma, and uses a spectrometer to analyze the plasma emission spectrum to identify the elemental composition of the sample, thereby enabling material identification, classification, qualitative and quantitative analysis.

[0003] In the metallurgical industry, due to the high temperature and dusty environment on site, most laser-induced breakdown spectroscopy equipment is remote telemetry. In order to reduce the influence of distance and dust, the aperture is often set larger, resulting in a larger probe body. The probe needs to face the object to be tested, which makes on-site installation more difficult. In addition, there is often an occasional large amount of smoke and dust on the metallurgical site that fills the detection path, which has an adverse effect on the measurement results and the service life of the lens.

[0004] Therefore, how to provide a laser induced breakdown spectroscopy detection device that is easy to use in a high-temperature dust environment is a problem that technical personnel in this field urgently need to solve. Summary of the invention

[0005] To this end, the purpose of the present invention is to propose a novel remote sensing laser induced breakdown spectroscopy detection system to solve the problems of many installation restrictions and the influence of high temperature and dust environment on the detection equipment, which causes the detection beam to be blocked by dust or a series of transmission and refraction, affecting the energy level of the laser emission and causing large errors in the measurement results.

[0006] The present invention provides a remote sensing laser induced breakdown spectroscopy detection system, comprising: The laser is provided with a lens barrel base in close proximity in front of the laser, and a first annular air knife and a laser beam expander are installed in the lens barrel base in sequence. The laser beam expander expands the laser into parallel light.

[0007] Furthermore, the rear end of the lens barrel base is connected to a first joint, and a first laser reflecting mirror is installed at 45 degrees in the first joint to reflect the parallel laser beam into the retractable middle lens barrel.

[0008] Furthermore, the retractable middle lens barrel is composed of a second laser reflecting mirror with a 45-degree angle, which reflects the parallel laser beam to the horizontal direction again.

[0009] Furthermore, the rear end of the retractable middle lens barrel is connected to a third joint, and a 45-degree third laser reflector is installed inside the third joint to reflect the parallel laser beam into the spectrum collection lens barrel.

[0010] Furthermore, the parallel laser beam passes through the dichroic mirror in the spectrum collection lens barrel, and is reflected into the terminal lens barrel via the 45-degree fourth aluminum film reflector inside the fourth joint.

[0011] Furthermore, the parallel laser beam is converged through the fused quartz glass in the end lens barrel and passes through the hollow second annular air knife, and is focused on the surface of the object to be measured, thereby ablating and generating plasma.

[0012] Furthermore, due to the reversible principle of the optical path, a portion of the plasma light passes through the fused quartz glass and turns back into parallel light, and after reaching the dichroic mirror, it is reflected to the spectrum collection lens and focused on the optical fiber coupling module.

[0013] Furthermore, the plasma light is coupled to the optical fiber in the optical fiber coupling module, transmitted to the spectrum detector, and the sample composition is calculated and analyzed by a computer.

[0014] Furthermore, due to the reversible principle of the optical path, the green laser is coaxial with the detection light beam and focused on the plasma to play an indicating role.

[0015] It can be seen from the above technical solution that compared with the prior art, the present invention has the following beneficial effects: The present invention adopts a retractable middle lens barrel, and can adjust the distance between the fused quartz lens and the sample to be tested according to the focal length of the fused quartz lens, so as to achieve the best detection effect and achieve a function similar to focusing.

[0016] The present invention uses four rotatable joints to connect the retractable lens barrel, so that the detection equipment does not need to face the sample to be tested directly, and can be installed and placed in any position. It only needs to adjust the end lens barrel to the position in front of the sample to be tested. At the same time, the laser; spectrum detector; computer are far away from the object to be tested to avoid the influence of high temperature radiation. The end lens barrel should be as close to the object to be tested as possible to shorten the detection distance, so the aperture of the fused quartz glass does not need to be very large, which can reduce the size of the equipment and realize miniaturized design, while also avoiding the influence of smoke caused by the long detection path.

[0017] The design of the first annular air knife in the present invention can continuously and evenly inject cooling air into the entire lens barrel structure, achieving air cooling and micro-positive pressure dust prevention effects on the optical path, and reducing the influence of thermal deformation of the lens caused by high temperature.

[0018] The design of the second annular air knife in the present invention can blow compressed air toward the surface of the object to be measured, further blowing away the smoke and dust in the detection path, thereby achieving a high-precision measurement effect and preventing pollutants from contaminating the fused quartz lens.

[0019] In the present invention, an aluminum film reflector is used at the fourth joint to achieve wide-band reflection from the ultraviolet spectrum to the infrared spectrum, so that the device structure is simple and the detection optical path and the collection optical path are coaxial.

[0020] In the present invention, a dichroic mirror is used in the spectrum collection lens barrel to make the laser light path and the spectrum collection light path coaxial, thereby eliminating the influence of liquid level fluctuation when measuring fluid samples and further reducing the size of the device.

[0021] In the present invention, the dichroic mirror is installed as close to the end of the device as possible, which can eliminate the influence of inconsistent spectral refractive index of plasma at different wavelengths as much as possible and obtain greater spectral intensity.

[0022] The present invention adopts a green laser and a Y-type optical fiber, which can focus the green light on the ablation position of the object to be tested without affecting the detection optical path, thereby indicating the specific detection position. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on the provided drawings without paying creative work.

[0024] Figure 1 The accompanying drawing shows a schematic diagram of a remote sensing laser induced breakdown spectroscopy detection system according to an embodiment of the present invention. DETAILED DESCRIPTION

[0025] Embodiments of the present invention are described in detail below, examples of which are shown in the accompanying drawings, wherein the same or similar reference numerals throughout represent the same or similar elements or elements having the same or similar functions. The embodiments described below with reference to the accompanying drawings are exemplary and are intended to be used to explain the present invention, and should not be construed as limiting the present invention.

[0026] In some industries, such as the metallurgical industry, the high-temperature dust environment on site will contaminate the probe of the detection device, causing the probe lens to blur, which may cause the detection beam to be blocked by dust or a series of transmission and refraction, affecting the energy level of the laser emission and causing large errors in the measurement results. At the same time, the probe of the detection device needs to face the high-temperature melt directly, and the internal temperature of the equipment is high, which affects the service life of the internal components and is also cumbersome to install.

[0027] In view of this, the present invention provides a remote sensing laser induced breakdown spectroscopy detection system, see the attached Figure 1 , comprising: a lens barrel base is placed closely in front of the laser (1), a first annular air knife (2) having a hollow structure and a laser beam expansion device (3) are installed in the lens barrel base. The laser beam is expanded into parallel light by the laser beam expansion device (3).

[0028] Advantageously, the first annular air knife (2) provides cooling air for the entire system, and its internal hollow structure does not affect the transmission of light.

[0029] It is worth noting that the laser beam expansion device (3) converts the laser beam into a wide beam of parallel light as much as possible, thereby reducing its energy density and preventing the laser energy from being too high to damage subsequent components.

[0030] In one embodiment, the rear end of the base (4) is connected to the first joint (5), and a first laser reflector (6) is installed at a 45-degree angle inside the first joint (5) to reflect the parallel laser beam into the retractable middle lens barrel (7). The retractable middle lens barrel (7) is spliced ​​with a second laser reflector (9) with a 45-degree angle to reflect the parallel laser beam to the horizontal direction again. The rear end of the retractable middle lens barrel (7) is connected to the third joint (10), and a third laser reflector (11) with a 45-degree angle is installed inside the third joint (10) to reflect the parallel laser beam into the spectrum collection lens barrel (12). Advantageously, rolling bearings are installed at both ends of the joints mentioned in the system, and the middle lens (7) can be extended or retracted, thereby achieving adjustment of the position and length of the entire system.

[0031] The parallel laser beam passes through the dichroic mirror (13) in the spectrum collection lens barrel (12), and is reflected into the end lens barrel (17) via the 45-degree fourth aluminum film reflector (19) inside the fourth joint (18). The parallel laser beam passes through the fused quartz glass (16) in the end lens barrel (17), converges and passes through the hollow second annular air knife (15), and is focused on the surface of the object to be measured, and ablates to generate plasma (14).

[0032] It is worth mentioning that the dichroic mirror (13) plays the role of transmitting laser light and reflecting light spectrum, and the aluminum film reflector can realize the reflection of wide-band wavelength light from ultraviolet band to infrared band, thereby achieving the effect of coaxiality between the subsequent laser light path and the collection light path.

[0033] Due to the principle of optical path reversibility, a portion of the plasma light passes through the fused silica glass (16) and turns back into parallel light. After reaching the dichroic mirror (13), it is reflected to the spectrum collection lens (20) and focused on the fiber coupling module (21). The plasma light is coupled to the Y-type optical fiber (22) in the fiber coupling module (21), transmitted to the spectrum detector (24), and its sample composition is calculated and analyzed by the computer (25). The green laser (23) is connected to the other end of the Y-type optical fiber (22). Due to the principle of optical path reversibility, the green laser (23) is coaxial with the detection beam and focused on the plasma, playing an indicating role.

[0034] Advantageously, laser-induced breakdown spectroscopy usually uses a 1064-nanometer wavelength laser, which is invisible to the naked eye. The design of the green laser and the detection optical path being coaxial allows the laser ablation position to be clearly seen without triggering the laser, which plays a good indicating role.

[0035] It is worth noting that, in the description of the present invention, it is necessary to understand that the terms "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", etc., indicating the orientation or position relationship are based on the orientation or position relationship shown in the accompanying drawings, which are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present invention.

[0036] It should be noted that the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Therefore, features defined as "first" and "second" may explicitly or implicitly include one or more of the features.

[0037] In the present invention, unless otherwise clearly specified and limited, terms such as "install", "connect", "connect", "fix" and the like should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integral one. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to the specific circumstances.

[0038] The remote sensing laser induced breakdown spectroscopy detection system provided by the present invention can realize the detection of samples in a high-temperature dust environment and can also be used in a general environment.

[0039] Advantageously, the present invention can be applied to laser detection probes as well as other types of atomic excitation detection devices.

[0040] In the description of this specification, the description with reference to the terms "one embodiment", "some embodiments", "example", "specific example", or "some examples" etc. means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described may be combined in any one or more embodiments or examples in a suitable manner. In addition, those skilled in the art may combine and combine different embodiments or examples described in this specification.

[0041] Although the embodiments of the present invention have been shown and described above, it is to be understood that the above embodiments are exemplary and are not to be construed as limitations of the present invention. A person skilled in the art may change, modify, replace and vary the above embodiments within the scope of the present invention.

Claims

1. A remote sensing laser induced breakdown spectroscopy detection system, characterized in that: The main structure includes: A laser (1), a base (4), a middle lens barrel (7), a spectrum collection lens barrel (12), a terminal lens barrel (17), and a spectrum analysis system; the base (4), the middle lens barrel (7), the spectrum collection lens barrel (12), and the terminal lens barrel (17) are connected end to end via a first joint (5), a second joint (8), a third joint (10), and a fourth joint (18).

2. A remote sensing laser induced breakdown spectroscopy detection system according to claim 1, characterized in that: Both ends of the first joint (5), the second joint (8), the third joint (10) and the fourth joint (18) are provided with rolling bearings installed in a direction perpendicular to the optical axis.

3. A remote sensing laser induced breakdown spectroscopy detection system according to claim 1, characterized in that: The middle lens barrel (7) can be telescopic in its axial direction.

4. A remote sensing laser induced breakdown spectroscopy detection system according to claim 1, characterized in that: A first annular air knife (2) and a second annular air knife (15) are installed at the front end of the base (4) and the rear end of the end lens barrel (17).

5. A remote sensing laser induced breakdown spectroscopy detection system according to claim 4, characterized in that: The first annular air knife (2) and the second annular air knife (15) are both hollow structures in the middle.

6. A remote sensing laser induced breakdown spectroscopy detection system according to claim 1, characterized in that: The base (4), the middle lens barrel (7), the spectrum collection lens barrel (12), the end lens barrel (17), the first joint (5), the second joint (8), the third joint (10), and the fourth joint (18) are all sealedly connected.

7. A remote sensing laser induced breakdown spectroscopy detection system according to claim 2, characterized in that: The first joint (5), the second joint (8), the third joint (10), and the fourth joint (18) are sequentially mounted at 45 degrees to each other with a first laser reflector (6), a second laser reflector (9), a third laser reflector (11), and a fourth aluminum film reflector (19).

8. A remote sensing laser induced breakdown spectroscopy detection system according to claim 1, characterized in that: A dichroic mirror (13), a spectral collection lens (20), and a spectral coupling module (21) are installed in the spectral collection lens barrel (12). The dichroic mirror (13) is installed at a 45-degree angle, transmits parallel laser light, and reflects plasma (14) light to the spectral collection lens (20) for collection.

9. A remote sensing laser induced breakdown spectroscopy detection system according to claim 8, characterized in that: The dichroic mirror (13) is installed as close as possible to the fused quartz glass (16) in space; the fused quartz glass (16) focuses the expanded laser light on the surface of the object to be measured for ablation, and at the same time collects the generated plasma light and converts it into parallel light to be sent into the spectrum collection lens barrel (12).

10. A remote sensing laser induced breakdown spectroscopy detection system according to claim 9, characterized in that: A remote sensing laser induced breakdown spectroscopy detection system according to claim 1, characterized in that the spectral analysis system comprises a Y-type optical fiber (22); one end of the optical fiber is connected to a green laser (23) and the other end is connected to a spectral detector (24); a computer (25); the optical fiber coupling module (21) is connected to the spectral detector (24) via the Y-type optical fiber (22); the spectral detector (24) is connected to the computer (25) and transmits spectral data of the material to be detected to the computer (25); the computer (25) analyzes and processes the received spectral data to obtain the composition information of the material to be detected.

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