Gun-head-replaceable LIBS component detection system in RH (Ruhrstahl Hereaeus) refining process

Abstract

The invention provides an RH refining process LI BS component detection system with a replaceable gun head, and relates to the technical field of ferrous metallurgy. According to the invention, through the long-distance light path module, focusing and light receiving processes are realized, only two plano-convex lenses are used in the process, and the system is simple and practical and has a high practical value; secondly, a detachable detection gun head is introduced into the long-distance light path module, so that an integrated structure of the optical lens and the detection gun head is realized, and the easy-to-wear optical lens is conveniently disassembled, assembled and maintained through the detachability of the gun head structure; thirdly, a nitrogen cooling circulation module is used, nitrogen cooling circulation is achieved on lenses, equipment and the like through a nitrogen circulation pipeline and a cooling circulation container, and stable work of the whole system is guaranteed; and finally, a real-time on-line forecasting module is used, original off-line pneumatic sample feeding is omitted, sample preparation and manual detection links are not needed, the manual labor cost is saved, the smelting detection efficiency is improved, and the system integration degree and the intelligent level are high.

Description

Technical Field

[0001] The present invention relates to the technical field of iron and steel metallurgy, and in particular to a LIBS component detection system for an RH refining process with a replaceable gun tip. Background Art

[0002] The RH refining furnace is a refining equipment used in the steel production process. It is mainly used for deoxidation, desulfurization, dephosphorization and other treatment processes of molten steel. It improves the quality of molten steel by removing impurities in the molten steel. The composition endpoint control of the refining process is a key control process related to the quality of steel products. This also provides new demands and challenges for intelligent equipment and real-time online detection of molten steel composition. The improvement of intelligent equipment and precise control of molten steel composition are of great significance to the industrial transformation and upgrading and high-quality development of the steel industry.

[0003] The refining furnace currently uses intermittent and offline detection to detect the composition of molten steel, which requires manual sampling. After the high-temperature liquid sample solidifies, the sample surface is processed by a milling machine to remove the oxide layer, and then the sample component content is detected using a spark direct reading spectrometer, carbon and sulfur meter, or ICP chemical dissolution method. Real-time synchronous online detection is not achieved, resulting in a lack of real-time and accuracy in process control. The intelligence level of molten steel composition detection in the steelmaking and refining process is low, and the endpoint hit rate is low. There is an urgent need to develop intelligent equipment for real-time online detection of molten steel composition in the refining process. Summary of the Invention

[0004] In order to solve the problems in the above-mentioned prior art, the present invention provides a LIBS component detection system for the RH refining process with a replaceable gun tip. The invention realizes the focusing and light collection process through a long-distance optical path module. The process only uses two plano-convex lenses, with a small number of lenses, accurate and reliable positioning, small optical path error, low cost, simplicity and practicality, and high practical value. Secondly, a detachable detection gun tip is introduced into the long-distance optical path module to realize an integrated structure of the optical lens and the detection gun tip. The detachable gun tip structure realizes convenient disassembly and maintenance of easily worn optical lenses, and has high engineering application value. Thirdly, a nitrogen cooling circulation module is used to realize nitrogen cooling circulation for lenses, equipment, etc. through nitrogen circulation pipelines and cooling circulation containers, thereby ensuring the stable operation of the entire system. Finally, a real-time online prediction module is used to eliminate the original offline pneumatic sample delivery, eliminate the need for sample preparation and manual detection links, save labor costs, improve smelting detection efficiency, and have high system integration and intelligence levels, and have important application value. To achieve the above-mentioned purposes, the technical solution is as follows:

[0005] The present invention provides a LIBS component detection system for RH refining process with replaceable gun tips, the system comprising:

[0006] Laser incident module, used to provide pulsed laser source for LIBS;

[0007] Long-distance optical path module, used to achieve LIBS optical path focusing and optical signal collection;

[0008] Spectral detection module, used to receive optical fiber light signals, convert the optical signals into electrical signals, and obtain spectral intensity and element concentration information;

[0009] A timing control module, used to perform logical sequence control on the working timing of the laser incident module and the spectrum detection module;

[0010] A nitrogen cooling circulation module is used to cool the detection system to ensure that the detection system works stably under low temperature conditions;

[0011] A real-time online prediction module, used for predicting the detection results of the detection system in real time;

[0012] The long-distance optical path module includes:

[0013] A reflector, used to change the direction of the laser emitted by the laser incident module and shoot it towards the detachable detection gun head unit;

[0014] The detachable detection gun head unit is used to focus and collect the light path of the LIBS;

[0015] a laser rangefinder for measuring the distance from the detachable inspection gun head unit to the surface of the molten metal;

[0016] A fiber collimator, used to collimate the optical path of the LIBS;

[0017] The optical fiber probe is used to receive the laser focused by the optical fiber collimator and transmit it to the spectrum detection module. The optical fiber probe and the optical fiber collimator are arranged in a collinear manner.

[0018] Optionally, the detachable detection gun head unit includes:

[0019] a first plano-convex mirror, used to focus the laser reflected by the reflector to achieve focusing of the long-distance optical path module;

[0020] A second plano-convex mirror is used to focus the plasma excited by the surface of the molten metal onto the optical fiber collimator to realize the light collection of the long-distance optical path module;

[0021] a lower cover plate, used for receiving the first plano-convex mirror and the second plano-convex mirror;

[0022] an upper cover plate, used for pressing together with the lower cover plate and realizing position limiting and fixing of the first plano-convex mirror and the second plano-convex mirror;

[0023] The gun head connecting plate is used to connect with the upper cover plate to realize a detachable structure.

[0024] Optionally, the distance between the first plano-convex mirror and the molten metal surface is the image distance h2 of the first plano-convex mirror, the distance x1 between the first plano-convex mirror and the reflector plus the distance x2 between the reflector and the light exit hole for laser incidence is the object distance h3 of the first plano-convex mirror, and the image distance h2 of the first plano-convex mirror, the object distance h3 of the first plano-convex mirror, and the focal length f1 of the first plano-convex mirror satisfy formula (1).

[0025] 1 / h2+1 / h3=1 / f1 (1)

[0026] Where: h2 is the image distance of the first plano-convex mirror, h3 is the object distance of the first plano-convex mirror, and f1 is the focal length of the first plano-convex mirror.

[0027] Optionally, the lower cover plate has two stepped holes, and the upper cover plate has two hollow bosses at positions corresponding to the two stepped holes. The lower cover plate is aligned with the upper cover plate, and the horizontal and transverse fixation of the lower cover plate and the upper cover plate is achieved by the cooperation of the hollow bosses and the stepped holes; the upper cover plate and the lower cover plate are horizontally and transversely fixed to form two annular grooves, and the annular grooves are used to embed the first plano-convex mirror and the second plano-convex mirror; the lower cover plate, the first plano-convex mirror, the second plano-convex mirror and the upper cover plate are vertically fixed in order from bottom to top through longitudinal threaded connections.

[0028] Optionally, the gun head connecting plate is located below the upper cover plate, and the gun head connecting plate is tightly fitted with the upper cover plate.

[0029] Optionally, the stepped hole includes: a first stepped hole and a second stepped hole; the flat end surface of the first plano-convex mirror cooperates with the step surface of the first stepped hole, and the step surface of the first stepped hole is perpendicular to the center line of the lower cover plate; the flat end surface of the second plano-convex mirror cooperates with the step surface of the second stepped hole, and the angle formed by the step surface of the second stepped hole and the step surface of the first stepped hole makes the intersection of the extension line of the central axis of the second plano-convex mirror and the extension line of the central axis of the first plano-convex mirror located at the laser focus of the molten metal surface, and the angle β between the central axis of the optical fiber probe and the vertical direction is equal to the angle a between the central axis of the second plano-convex mirror and the vertical axis of the second plano-convex mirror.

[0030] Optionally, the axis of the second plano-convex mirror is collinear with the axes of the fiber optic probe and the fiber optic collimating mirror.

[0031] Optionally, the outer end surface of the hollow boss is a concave arc surface.

[0032] Optionally, the nitrogen cooling circulation module includes:

[0033] A nitrogen circulation pipeline for cooling the long-distance optical path module and providing cooling power for the cooling circulation container;

[0034] The cooling cycle container is used to provide a cooling space;

[0035] The cooling circulation container is used to provide a cooling space.

[0036] Compared with the prior art, the technical solution of the present invention has at least the following beneficial effects:

[0037] On the one hand, the above scheme realizes the focusing and light collecting process through the long-distance optical path module. This process only uses two plano-convex lenses, with a small number of lenses, accurate and reliable positioning, small optical path error, low cost, simplicity and practicality, and high practical value; on the other hand, a detachable detection gun head is introduced into the long-distance optical path module to realize the integrated structure of the optical lens and the detection gun head. The detachable gun head structure realizes the convenient disassembly and maintenance of the easily worn optical lens, and has high engineering application value; on the third hand, a nitrogen cooling circulation module is used to realize nitrogen cooling circulation for lenses, equipment, etc. through nitrogen circulation pipelines and cooling circulation containers, thereby ensuring the stable operation of the entire system; on the fourth hand, a real-time online prediction module is used to eliminate the original offline pneumatic sample delivery, and there is no need to prepare samples and manual detection links, which saves labor costs and improves smelting detection efficiency. The system has high integration and intelligence levels and has important application value. BRIEF DESCRIPTION OF THE DRAWINGS

[0038] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the following briefly introduces the drawings required for use in the description of the embodiments. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.

[0039] Figure 1 This is a system block diagram of an embodiment of the LIBS component detection system for the RH refining process with replaceable gun tips of the present invention;

[0040] Figure 2 This is a schematic diagram of the optical path principle of an embodiment of the LIBS component detection system for the RH refining process with replaceable gun tips of the present invention;

[0041] Figure 3 2. It is a schematic structural diagram of a detachable detection gun tip module of an embodiment of the RH refining process LIBS component detection system with replaceable gun tips of the present invention;

[0042] Figure 4This is a schematic structural diagram of the upper cover plate of an embodiment of the LIBS component detection system for the RH refining process with replaceable gun tips of the present invention;

[0043] Figure 5 It is a structural schematic diagram of the lower cover plate of an embodiment of the LIBS component detection system for the RH refining process with replaceable gun tips of the present invention.

[0044] Explanation of the numbers in the figure: reflector 1, pulse laser 2, digital delayed pulse machine 3, industrial computer 4, ICCD spectrometer 5, cooling circulation container 6, long-distance optical path module 7, vacuum induction furnace 8, molten metal 9, laser rangefinder 10, first plano-convex mirror 11, optical fiber probe 12, optical fiber collimating mirror 13, second plano-convex mirror 14, gun head connecting plate 15, upper cover plate 16, lower cover plate 17. DETAILED DESCRIPTION

[0045] The technical solution of the present invention is described below in conjunction with the accompanying drawings.

[0046] In the embodiments of the present invention, words such as "exemplarily" and "for example" are used to indicate examples, illustrations or explanations; any embodiment or design described as "example" in the present invention should not be interpreted as being more preferred or more advantageous than other embodiments or designs; to be precise, the use of the word "example" is intended to present concepts in a concrete way; in addition, in the embodiments of the present invention, the meaning expressed by "and / or" can be both, or it can be either of the two.

[0047] In order to make the technical problems, technical solutions and advantages to be solved by the present invention clearer, a detailed description will be given below with reference to the accompanying drawings and specific embodiments.

[0048] like Figure 1 The system block diagram of the embodiment of the RH refining process LIBS component detection system of the present invention with replaceable gun tips is shown in FIG. Figure 2 The optical path principle diagram of an embodiment of the LIBS component detection system for the RH refining process with an interchangeable tip of the present invention is shown. The present invention provides a LIBS component detection system for the RH refining process with an interchangeable tip, which includes: a laser incident module, a long-distance optical path module 7, a spectrum detection module, a timing control module, a nitrogen cooling circulation module, and a real-time online prediction module;

[0049] Laser incident module, used to provide pulsed laser source for LIBS;

[0050] Specifically, the laser incident module is a pulse laser 2;

[0051] Furthermore, the pulse laser 2 has an operating voltage of 220V, a laser energy of 200mJ, and an emitted laser is a pulse laser with a single wavelength of 1064nm.

[0052] Long-distance optical path module 7, used to achieve LIBS optical path focusing and optical signal collection;

[0053] Specifically, the long-distance optical path module 7 includes:

[0054] Reflector 1, used to change the direction of the laser emitted by the laser incident module to the detachable detection gun head unit;

[0055] Furthermore, the reflector 1 is made of quartz and has a circular shape;

[0056] The detachable detection gun head unit is used to focus and collect the light path of the LIBS;

[0057] Furthermore, if Figure 3 The schematic diagram of the structure of the detachable detection gun tip module of the embodiment of the RH refining process LIBS component detection system with replaceable gun tips of the present invention is shown as follows Figure 4 The structural diagram of the upper cover plate of the embodiment of the RH refining process LIBS component detection system with replaceable gun tips of the present invention is shown as follows Figure 5 The structure diagram of the lower cover plate of the embodiment of the RH refining process LIBS component detection system with replaceable gun tips of the present invention is shown. The detachable detection gun tip unit includes:

[0058] A first plano-convex mirror 11 is used to focus the laser reflected by the reflector 1 to achieve focusing of the long-distance optical path module;

[0059] A second plano-convex mirror 14 is used to focus the plasma excited on the surface of the molten metal 9 to the optical fiber collimator 13 to realize the light collection of the long-distance optical path module 7. The molten metal 9 is located in the vacuum induction furnace 8;

[0060] A lower cover plate 17 is used to receive the first plano-convex mirror 11 and the second plano-convex mirror 14;

[0061] The upper cover plate 16 is used to press fit with the lower cover plate 17 to achieve position limiting and fixing of the first plano-convex mirror 11 and the second plano-convex mirror 14;

[0062] The distance between the first plano-convex mirror 11 and the surface of the molten metal 9 is the image distance h2 of the first plano-convex mirror. The distance x1 between the first plano-convex mirror 11 and the reflector 1 plus the distance x2 between the reflector and the laser incident light output hole is the object distance h3 of the first plano-convex mirror 11. The image distance h2 of the first plano-convex mirror 11, the object distance h3 of the first plano-convex mirror 11 and the focal length f1 of the first plano-convex mirror 11 satisfy formula (1).

[0063] 1 / h2+1 / h3=1 / f1 (1)

[0064] Where: h2 is the image distance of the first plano-convex mirror, h3 is the object distance of the first plano-convex mirror, and f1 is the focal length of the first plano-convex mirror.

[0065] Furthermore, the diameter of the first plano-convex mirror 11 is φ25.4 mm, and the thickness of the lens is 3.5 mm; the diameter of the second plano-convex mirror is φ150 mm, the center thickness of the lens is 25 mm, and the thickness of the outermost edge of the lens is about 5 mm; the distance between the first plano-convex mirror 11 and the surface of the molten metal below is the image distance h2 of the first plano-convex mirror 11 = 1550 mm, and this size can ensure that the first plano-convex mirror 11 focuses the laser on the surface of the molten metal 9 to excite plasma; the sum of the distance x1 between the first plano-convex mirror 11 and the reflector 1 and the distance x2 between the reflector 1 and the laser light exit hole is the object distance h3 of the first plano-convex mirror 11, that is, x1+x2=h3=1700 mm; the image distance h2 of the first plano-convex mirror 11, the object distance h3 of the first plano-convex mirror 11 and the focal length f1 of the first plano-convex mirror 11 satisfy formula (1),

[0066] 1 / h2+1 / h3=1 / f1 (1)

[0067] Where: h2 is the image distance of the first plano-convex mirror, h3 is the object distance of the first plano-convex mirror, and f1 is the focal length of the first plano-convex mirror.

[0068] The distance between the second plano-convex mirror 14 and the optical fiber collimator 13 is the image distance h1 of the second plano-convex mirror 14 = 340 mm, the distance between the second plano-convex mirror 14 and the laser focus on the surface of the molten metal 9 is the object distance of the second plano-convex mirror 14, and the image distance of the second plano-convex mirror 14, the object distance of the second plano-convex mirror 14 and the focal length of the second plano-convex mirror 14 also satisfy the relationship of formula (1).

[0069] The lower cover plate 17 has two stepped holes, and the upper cover plate 16 has two hollow bosses at positions corresponding to the two stepped holes. The lower cover plate 17 is aligned with the upper cover plate 16, and the lower cover plate 17 and the upper cover plate 16 are laterally fixed by the cooperation of the hollow bosses and the stepped holes; the upper cover plate 16 and the lower cover plate 17 are laterally fixed to form two annular grooves, which are used to embed the first plano-convex mirror 11 and the second plano-convex mirror 14; the lower cover plate 17, the first plano-convex mirror 11, the second plano-convex mirror 14 and the upper cover plate 16 are longitudinally fixed by longitudinal threaded connection in order from bottom to top.

[0070] Furthermore, the stepped hole includes: a first stepped hole and a second stepped hole; the center distance between the first stepped hole and the second stepped hole is d1 = 110 mm; the flat end surface of the first plano-convex mirror 11 cooperates with the step surface of the first stepped hole, and the step surface of the first stepped hole is perpendicular to the center line of the lower cover plate 17; the flat end surface of the second plano-convex mirror 14 cooperates with the step surface of the second stepped hole, and the angle formed by the step surface of the second stepped hole and the step surface of the first stepped hole makes the intersection of the extension line of the central axis of the second plano-convex mirror 14 and the extension line of the central axis of the first plano-convex mirror 11 located at the laser focus of the molten metal surface.

[0071] The center distance d1 of the first stepped hole and the second stepped hole is 110 mm, the distance from the center of the second plano-convex mirror 14 to the focal point of the surface of the molten metal 9, and the distance h2 of the first plano-convex mirror 11 to the surface of the molten metal 9 is 1550 mm, which satisfy the Pythagorean theorem. The inclination angle of the step surface of the second stepped hole that cooperates with the second plano-convex mirror 14 is α. After the second plano-convex mirror 14 cooperates with the step surface of the second stepped hole of the lower cover plate 17, the angle between the central axis of the second plano-convex mirror 14 and the vertical direction is α, and α is 4°.

[0072] The central axis of the second plano-convex mirror 14 is collinear with the central axes of the fiber optic probe 12 and the fiber optic collimating lens 13 .

[0073] The outer end surface of the hollow boss of the upper cover plate 16 is an inwardly concave arc surface.

[0074] The gun head connecting plate 15 is used to connect with the upper cover plate 16 to realize a detachable structure.

[0075] Furthermore, the gun head connecting plate 15 is located below the upper cover plate 16, and 6 through holes are evenly arranged on the outer circle of the upper cover plate 16. The gun head connecting plate 15 is tightly fitted with the upper cover plate 16. The gun head connecting plate 15 has 6 through holes corresponding to it, which are tightly fitted with the 6 through holes of the gun head connecting plate 15, the 6 through holes of the upper cover plate 16, and the 6 threaded holes on the bottom end face of the gun head of the long-distance optical path module 7 through bolts.

[0076] A laser rangefinder, used to measure the distance from the detachable inspection gun head unit to the molten metal surface;

[0077] Furthermore, the laser rangefinder 10 uses imported equipment with a red light single wavelength of 650nm and an accuracy of 0.1mm. In order to ensure the accuracy of distance measurement, the angle between the laser rangefinder 10 and the vertical downward axis should be less than 15° when working.

[0078] A fiber collimator 13 is used to collimate the optical path of the LIBS;

[0079] The optical fiber probe 12 is used to receive the laser focused by the optical fiber collimator 13 and transmit it to the spectrum detection module. The optical fiber probe 12 and the optical fiber collimator 13 are arranged in a collinear manner.

[0080] Furthermore, the fiber optic collimator 13 and the fiber optic probe 12 form an integral structure through the SMA905 interface, which is used to reduce the cumulative error of light path focusing and light collection, so as to improve the stability of spectral quality; at the same time, the integral structure is coaxial with the second plano-convex mirror 14, and the angle β between the central axis of the fiber optic probe 12 and the vertical direction is equal to the angle α between the central axis of the second plano-convex mirror 14 and the vertical direction, both of which are 4°.

[0081] Spectral detection module, used to receive optical fiber light signals, convert the optical signals into electrical signals, and obtain spectral intensity and element concentration information;

[0082] Specifically, the spectrum detection module is an ICCD spectrometer 5;

[0083] Furthermore, the ICCD spectrometer 5 has a resolution of λ / 6000nm and an integration time of 1ms. The resolution of each channel is different. The ICCD spectrometer 5 has a wavelength range of 199-936nm, which is used for photoelectric signal conversion. Finally, the spectral intensity and element concentration information are presented to the real-time online prediction module to complete the entire light collection process.

[0084] A timing control module, used for performing logical sequence control on the working timing of the laser incident module and the spectrum detection module;

[0085] Specifically, the timing control module is a digital delay pulse machine 3;

[0086] Furthermore, the digital delayed pulse machine 3 is provided with two channels, which are respectively set to 100 μs and 110 μs, and the voltage is set to 5 V. The digital delayed pulse machine 3 is used to control the timing signals of the pulse laser 2 and the ICCD spectrometer 5 .

[0087] Nitrogen cooling circulation module, used to cool the detection system to ensure that the detection system works stably under low temperature conditions;

[0088] Specifically, the nitrogen cooling circulation module includes:

[0089] A nitrogen circulation pipeline is used to cool the long-distance optical path module 7 and provide cooling power for the cooling circulation container 6;

[0090] A cooling circulation container 6 is used to provide a cooling space;

[0091] Furthermore, a nitrogen circulation pipe is located in the long-distance optical path module 7, which is used to cool the first plano-convex mirror 11 and the second plano-convex mirror 14; the cooling circulation container 6 is located on the top platform of the long-distance optical path module 7, and cools the reflector 1, pulse laser 2, digital delayed pulse machine 3, industrial computer 4 and ICCD spectrometer 5, and uses nitrogen cooling circulation to cool the equipment.

[0092] A real-time online prediction module is used to predict the detection results of the detection system in real time;

[0093] Specifically, the computer used in the real-time online prediction module is an industrial computer 4, which integrates hardware equipment and software algorithms and can work in standby mode all year round. By acquiring data from the spectrum detection module, the industrial computer 4 can perform real-time online prediction of the LIBS composition detection results of the molten steel liquid in the RH refining process.

[0094] The present invention provides a LIBS component detection system for the RH refining process with a replaceable gun tip. The invention realizes the focusing and light collecting processes through a long-distance optical path module. The process only uses two plano-convex lenses, with a small number of lenses, accurate and reliable positioning, small optical path error, low cost, simplicity and practicality, and high practical value. Secondly, a detachable detection gun tip is introduced into the long-distance optical path module to realize an integrated structure of the optical lens and the detection gun tip. The detachable gun tip structure realizes convenient disassembly and maintenance of easily worn optical lenses, and has high engineering application value. Thirdly, a nitrogen cooling circulation module is used to realize nitrogen cooling circulation for lenses, equipment, etc. through a nitrogen circulation pipeline and a cooling circulation container, thereby ensuring the stable operation of the entire system. Finally, a real-time online prediction module is used to eliminate the original offline pneumatic sample delivery, and there is no need for sample preparation and manual detection links, thereby saving labor costs and improving smelting detection efficiency. The system has high integration and intelligence levels and has important application value.

[0095] It can be understood that the present invention is described through the above embodiments and should not be interpreted as limiting the implementation mode of the present invention and the scope of the present invention; those skilled in the art will appreciate that various changes or equivalent substitutions may be made to these features and embodiments without departing from the spirit and scope of the present invention; in addition, under the teachings of the present invention, these features and embodiments may be modified to adapt to specific circumstances and materials without departing from the spirit and scope of the present invention; therefore, the present invention is not limited to the specific embodiments disclosed herein, and all embodiments that fall within the scope of the claims of this application fall within the scope of protection of the present invention.

Claims

1. A LIBS component detection system for RH refining process with replaceable gun tip, characterized by: The system comprises: Laser incident module, used to provide pulsed laser source for LIBS; Long-distance optical path module, used to achieve LIBS optical path focusing and optical signal collection; Spectral detection module, used to receive optical fiber light signals, convert the optical signals into electrical signals, and obtain spectral intensity and element concentration information; A timing control module, used to perform logical sequence control on the working timing of the laser incident module and the spectrum detection module; A nitrogen cooling circulation module is used to cool the detection system to ensure that the detection system works stably under low temperature conditions; A real-time online prediction module, used for predicting the detection results of the detection system in real time; The long-distance optical path module includes: A reflector, used to change the direction of the laser emitted by the laser incident module and shoot it towards the detachable detection gun head unit; The detachable detection gun head unit is used to focus and collect the light path of the LIBS; a laser rangefinder for measuring the distance from the detachable inspection gun head unit to the surface of the molten metal; A fiber collimator, used to collimate the optical path of the LIBS; The optical fiber probe is used to receive the laser focused by the optical fiber collimator and transmit it to the spectrum detection module. The optical fiber probe and the optical fiber collimator are arranged in a collinear manner.

2. The RH refining process LIBS component detection system with replaceable gun tips according to claim 1 is characterized in that: The detachable detection gun head unit includes: a first plano-convex mirror, used to focus the laser reflected by the reflector to achieve focusing of the long-distance optical path module; A second plano-convex mirror is used to focus the plasma excited by the surface of the molten metal onto the optical fiber collimator to realize the light collection of the long-distance optical path module; a lower cover plate, used for receiving the first plano-convex mirror and the second plano-convex mirror; an upper cover plate, used for pressing together with the lower cover plate and realizing position limiting and fixing of the first plano-convex mirror and the second plano-convex mirror; The gun head connecting plate is used to connect with the upper cover plate to realize a detachable structure.

3. The RH refining process LIBS component detection system with replaceable gun tips according to claim 2 is characterized in that: The distance between the first plano-convex mirror and the molten metal surface is the image distance h2 of the first plano-convex mirror, the distance x1 between the first plano-convex mirror and the reflector plus the distance x2 between the reflector and the light exit hole for laser incidence is the object distance h3 of the first plano-convex mirror, and the image distance h2 of the first plano-convex mirror, the object distance h3 of the first plano-convex mirror, and the focal length f1 of the first plano-convex mirror satisfy formula (1). 1 / h2+1 / h3=1 / f1 (1) Where: h2 is the image distance of the first plano-convex mirror, h3 is the object distance of the first plano-convex mirror, and f1 is the focal length of the first plano-convex mirror.

4. The RH refining process LIBS component detection system with replaceable gun tips according to claim 2 is characterized in that: The lower cover plate has two stepped holes, and the upper cover plate has two hollow bosses at positions corresponding to the two stepped holes. The lower cover plate is aligned with the upper cover plate, and the horizontal and transverse fixation of the lower cover plate and the upper cover plate is achieved by the cooperation of the hollow bosses and the stepped holes; the upper cover plate and the lower cover plate are horizontally and transversely fixed to form two annular grooves, and the annular grooves are used to embed the first plano-convex mirror and the second plano-convex mirror; the lower cover plate, the first plano-convex mirror, the second plano-convex mirror and the upper cover plate are vertically fixed by longitudinal threaded connection in order from bottom to top.

5. The RH refining process LIBS component detection system with replaceable gun tips according to claim 4 is characterized in that: The gun head connecting plate is located below the upper cover plate, and the gun head connecting plate is tightly matched with the upper cover plate.

6. The RH refining process LIBS component detection system with replaceable gun tips according to claim 4 is characterized in that: The stepped hole includes: a first stepped hole and a second stepped hole; the flat end surface of the first plano-convex mirror cooperates with the step surface of the first stepped hole, and the step surface of the first stepped hole is perpendicular to the center line of the lower cover plate; the flat end surface of the second plano-convex mirror cooperates with the step surface of the second stepped hole, and the angle formed by the step surface of the second stepped hole and the step surface of the first stepped hole is such that the intersection of the extension line of the central axis of the second plano-convex mirror and the extension line of the central axis of the first plano-convex mirror is located at the laser focus of the molten metal surface, and the angle β between the central axis of the optical fiber probe and the vertical direction is equal to the angle a between the central axis of the second plano-convex mirror and the vertical axis of the second plano-convex mirror.

7. The RH refining process LIBS component detection system with replaceable gun tips according to claim 5 is characterized in that: The axis of the second plano-convex mirror is collinear with the axes of the optical fiber probe and the optical fiber collimating mirror.

8. The RH refining process LIBS component detection system with replaceable gun tips according to claim 4 is characterized in that: The outer end surface of the hollow boss is an inwardly concave arc surface.

9. The RH refining process LIBS component detection system with replaceable gun tips according to claim 1 is characterized in that: The nitrogen cooling circulation module comprises: A nitrogen circulation pipeline for cooling the long-distance optical path module and providing cooling power for the cooling circulation container; The cooling cycle container is used to provide a cooling space; The cooling circulation container is used to provide a cooling space.

Images