An air curtain structure and LIBS detection device for real-time LIBS detection of high-temperature molten samples

Abstract

The present application belongs to the field of analysis and detection technology, and relates to an air curtain structure and a LIBS detection device for real-time LIBS detection of high-temperature molten samples, comprising a first mounting part and a second mounting part, wherein a window piece is mounted on the first mounting part, and an air outlet is provided on the second mounting part; the first mounting part and the second mounting part are enclosed so that an air inlet chamber is formed between the first mounting part and the second mounting part; a laser incident channel is formed between the window piece, the air inlet chamber and the air outlet; and an air inlet is introduced into the air inlet chamber, wherein the air inlet area of ​​the air inlet is larger than the air outlet area of ​​the air outlet; the present invention increases the flow rate of the air outlet by increasing the area ratio of the air inlet to the air outlet. The high flow rate can not only inhibit the volatile matter of the high-temperature sample from flowing to the window piece and affecting the window piece, but also inhibit the window piece contamination caused by the laser acting on the high-temperature liquid sample and splashing. In addition, the contact surface can also be cooled.

Description

Technical Field

[0001] The present application belongs to the field of analysis and detection technology, and more specifically, relates to an air curtain structure and a LIBS detection device for real-time LIBS detection of high-temperature molten samples. Background Art

[0002] Laser-induced breakdown spectroscopy (LIBS) uses laser pulses to generate a localized plasma on the sample surface. Analyzing the plasma's emission spectrum allows for qualitative and quantitative elemental analysis. LIBS requires no complex sample preparation, can simultaneously detect multiple elements, and has a fast response time. It is ideal for real-time monitoring in high-temperature environments and shows great potential for detecting strategic elements in these environments. Currently, LIBS, using specially designed optical systems, has been successfully applied to surface composition analysis of uranium fuel rods and detection of fission products in molten salts, enabling remote measurement in radioactive environments. In metallurgical process monitoring, LIBS systems are installed directly near furnaces, enabling online composition analysis of high-temperature melts such as molten iron and aluminum, providing real-time data support for smelting process optimization. In high-temperature materials research, LIBS, combined with hot stages, enables in situ observation of elemental migration during heating, offering new insights into high-temperature failure mechanisms.

[0003] Although LIBS systems are currently being applied to high-temperature samples containing strategic elements, when examining high-temperature molten samples, volatiles can contaminate the optical windows, causing the laser focus to drift and optical signal attenuation. Furthermore, interference from the plasma's thermal radiation background can lead to insufficient stability in detecting trace elements when examining high-temperature samples. Summary of the Invention

[0004] The present invention provides an air curtain structure and a LIBS detection device for real-time LIBS detection of high-temperature molten samples, aiming to solve the technical problem that when detecting high-temperature molten samples, volatile substances may contaminate the optical window, causing the laser focus to drift and the optical signal to attenuate.

[0005] First, it should be noted that the high temperature referred to in the present invention is a temperature above 200°C.

[0006] In one aspect, the present invention provides an air curtain structure for real-time LIBS detection of high-temperature molten samples, comprising a first mounting portion and a second mounting portion, wherein a window piece is mounted on the first mounting portion, and an air outlet is provided on the second mounting portion; the first mounting portion and the second mounting portion are enclosed, so that an air inlet chamber is formed between the first mounting portion and the second mounting portion;

[0007] A laser incident channel is formed between the window piece, the air inlet chamber and the air outlet; and an air inlet is introduced into the air inlet chamber, wherein the air inlet area is larger than the air outlet area.

[0008] In the present invention, protective gas is introduced through the air inlet and flows out from the air outlet. Since the air inlet area is larger than the air outlet area, the gas flow rate of the air outlet is increased, which prevents volatiles from entering the air inlet chamber through the air outlet and contaminating the window piece. In this way, the problem of optical window contamination can be effectively prevented; and since the gas flow rate of the air outlet is increased, the contact surface can be effectively cooled. Therefore, the present invention increases the area ratio of the air inlet and the air outlet, that is, the air inlet area is larger than the air outlet area, thereby increasing the flow rate of the air outlet. The high flow rate can not only inhibit the volatiles of the high-temperature sample from flowing to the window piece and affecting the window piece, but also inhibit the window piece contamination caused by the laser acting on the high-temperature liquid sample splashing, and can also cool the contact surface.

[0009] Preferably, the air inlet is installed on a side wall of the air inlet chamber and intakes air toward the window sheet.

[0010] Preferably, the air inlet chamber is funnel-shaped, and the diameter of one end close to the first mounting portion is larger than the diameter of one end close to the second mounting portion.

[0011] Preferably, an electrode rod is provided on the second mounting portion.

[0012] On the other hand, the present invention provides a high-temperature molten sample real-time LIBS detection device, comprising a laser, an optical path module, a spectrometer module, and an air curtain module, wherein the air curtain module adopts the air curtain structure for real-time LIBS detection of high-temperature molten samples described in the present invention;

[0013] The optical path module is provided with a spectrum incident port, a laser incident port and an output port, wherein the output port faces the window piece of the air curtain structure.

[0014] Preferably, the optical path module includes a reflector, a plano-concave lens, a plano-convex lens and a dichroic mirror;

[0015] The laser light emitted by the laser is reflected by the reflector and then passes through the plano-concave lens, the plano-convex lens, the dichroic mirror, the window, the air inlet chamber and the air outlet of the air curtain structure in sequence to act on the sample to be tested;

[0016] The light source output by the spectrometer module passes through the dichroic mirror, and then sequentially passes through the window, the air inlet chamber, and the air outlet of the air curtain structure to act on the sample to be tested.

[0017] Preferably, the plano-concave lens or the plano-convex lens is mounted on a first displacement module, and the first displacement module is driven by a driving device so that the first displacement module can perform reciprocating linear motion between the reflector and the dichroic mirror.

[0018] Preferably, the laser, optical path module, spectrometer module and air curtain structure are all installed on the second displacement module, and the second displacement module is driven by a driving device to control the movement of the second displacement module, so that the air outlet of the air curtain structure acts on the sample to be monitored.

[0019] Preferably, the real-time LIBS detection device further comprises a sensing module, which is used to detect the spatial position between the sample to be tested and the sample detection end.

[0020] Preferably, the perception module adopts an optical rangefinder.

[0021] In the present invention, protective gas is introduced through the air inlet and flows out from the air outlet. Since the air inlet area is larger than the air outlet area, the gas flow rate of the air outlet is increased, which prevents volatiles from entering the air inlet chamber through the air outlet and contaminating the window piece, thereby effectively preventing the problem of optical window contamination; and since the gas flow rate of the air outlet is increased, the contact surface can be effectively cooled; therefore, the present invention increases the area ratio of the air inlet and the air outlet, that is, the area of ​​the air inlet is larger than the area of ​​the air outlet, thereby increasing the flow rate of the air outlet. The high flow rate can not only inhibit the volatiles of the high-temperature sample from flowing to the window piece and affecting the window piece, but also inhibit the window piece contamination caused by the laser acting on the high-temperature liquid sample splashing, and can also cool the contact surface. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the following briefly introduces the drawings required for use in the embodiments or descriptions of the prior art. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without any creative work.

[0023] Figure 1 This is a schematic diagram of the air curtain structure provided in Example 1 of the present invention.

[0024] Figure 2 This is a schematic structural diagram of the LIBS detection device provided in Example 3 of the present invention.

[0025] Figure 3 This is a diagram showing the detection results of nuclear elements in a high-temperature molten sample provided in Example 3 of the present invention.

[0026] Explanation of Reference Numerals: 1. Air curtain structure; 11. First mounting portion; 12. Air inlet chamber; 13. Air inlet; 14. Second mounting portion; 15. Air outlet; 16. Electrode rod; 17. Hollow portion; 2. Laser; 3. Spectrometer module; 4. Off-axis parabolic mirror; 5. Sensing module; 6. Window; 7. Optical path module; 71. Dichroic mirror; 72. Plano-convex lens; 73. Plano-concave lens; 74. Reflector; 8. First displacement module; 9. Second displacement module; DETAILED DESCRIPTION

[0027] In order to make the technical problems, technical solutions and beneficial effects to be solved by this application more clearly understood, this application is further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain this application and are not intended to limit this application.

[0028] Example 1

[0029] An air curtain structure for real-time LIBS detection of high-temperature molten samples includes a first mounting portion 11 and a second mounting portion 14. The first mounting portion 11 is mounted with a window piece 6, and the second mounting portion 14 is provided with an air outlet 15. The first mounting portion 11 and the second mounting portion 14 are enclosed, so that an air inlet chamber 12 is formed between the first mounting portion 11 and the second mounting portion 14.

[0030] A laser incident channel is formed between the window 6 , the air inlet chamber 12 and the air outlet 15 ; and an air inlet 13 is introduced into the air inlet chamber 12 , wherein the air inlet area of ​​the air inlet 13 is larger than the air outlet area of ​​the air outlet 15 .

[0031] In the present invention, protective gas is introduced into the air inlet 13 and flows out of the protective gas through the air outlet 15. Since the air inlet area of ​​the air inlet 13 is larger than the air outlet area of ​​the air outlet 15, the gas flow rate of the air outlet 15 is increased, and volatiles are prevented from entering the air inlet chamber 12 through the air outlet 15 and contaminating the window piece 6. This can effectively prevent the problem of optical window contamination; and since the gas flow rate of the air outlet 15 is increased, the contact surface can be effectively cooled. Therefore, the present invention increases the area ratio of the air inlet 13 and the air outlet 15, that is, the area of ​​the air inlet 13 is larger than the area ratio of the air outlet 15, thereby increasing the flow rate of the air outlet 15. The high flow rate can not only inhibit the volatiles of the high-temperature sample from flowing to the window piece 6 and affecting the window piece 6, but also inhibit the window piece 6 from being contaminated by the laser acting on the splash of the high-temperature liquid sample. In addition, the contact surface can also be cooled.

[0032] In this embodiment, the window piece 6 can be embedded in the first installation portion 11 , and a hollow portion 17 having a size adapted to the window piece 6 is provided on the first installation portion 11 , and the window piece 6 can be installed in the hollow portion 17 .

[0033] See also Figure 1 As shown, as a further implementation method of this embodiment, the air inlet 13 is installed on the side wall of the air inlet chamber 12, and air is introduced toward the window piece 6; in this embodiment, the air inlet 13 is directed toward the window piece 6, so that the protective gas blown into the air inlet 13 directly acts on the window piece 6, and then after passing through the window piece 6, the air flow enters the air outlet 15, thereby further preventing the window piece 6 from being contaminated.

[0034] As a further implementation of this embodiment, the air inlet chamber 12 is funnel-shaped, with the diameter of the end near the first mounting portion 11 being larger than the diameter of the end near the second mounting portion 14. Due to the funnel-shaped air inlet chamber 12, a diversion effect caused by the pressure and the inner wall structure of the chamber is formed within the air inlet chamber 12, guiding the gas toward the air outlet 15, further preventing the window 6 from being contaminated.

[0035] As a possible implementation of this embodiment, an electrode rod 16 is provided on the second mounting portion 14, wherein the electrode rods 16 are two and are arranged at 180° intervals with the center of the gas outlet 15 as the center; the high-temperature sample is electrolyzed by the electrode rods 16 to prevent the sample from undergoing an oxidation-reduction reaction.

[0036] Example 2

[0037] The only difference between this embodiment 2 and embodiment 1 is that the setting of the air inlet 13 is different from that of embodiment 1. For example, the diameter of the air inlet 13 is set in the range of 4-8 mm; the circular diameter of the top of the air inlet chamber 12 (close to the first mounting portion 11) is 50-75 mm; the diameter of the air outlet 15 is 10-15 mm; from the above value range, it can be seen that the air inlet area of ​​the air inlet 13 is significantly smaller than the air outlet area of ​​the air outlet 15, but because the air inlet 13 faces the window piece 6, and the window piece 6 is located at the top of the air inlet chamber 12, its area is much larger than the area of ​​the air outlet 15. Therefore, in this embodiment, the air inlet 13 is actually a quick connector, and the top of the air inlet chamber 12 forms the large-area air inlet, thereby making the air inlet area larger than the air outlet area, thereby increasing the flow rate of the air outlet 15.

[0038] Regarding the technical solutions of Examples 1 and 2, the present application should clarify that the present invention only requires that the area of ​​the air inlet portion be greater than the area of ​​the air outlet portion. Alternatively, the cross-sectional area can gradually decrease from the air inlet portion to the air outlet portion, and the joint portion is not included. The joint is only for the purpose of inducing the shielding gas. In other words, in Example 2, the air inlet is formed by the air inlet 13 and the top of the air inlet chamber 12. The actual air inlet area is the top of the air inlet chamber 12, thereby making the air inlet area greater than the air outlet area.

[0039] Example 3

[0040] A high-temperature molten sample real-time LIBS detection device, comprising a laser 2, an optical path module 7, a spectrometer module 3, and an air curtain module, wherein the air curtain module adopts the air curtain structure 1 for real-time LIBS detection of high-temperature molten samples described in the present invention;

[0041] The optical path module 7 is provided with a spectrum incident port, a laser incident port, and an exit port, wherein the exit port faces the window piece 6 of the air curtain structure 1 .

[0042] As a possible implementation of this embodiment, the optical path module includes a reflector 74, a plano-concave lens 73, a plano-convex lens 72 and a dichroic mirror 71;

[0043] The laser light emitted by the laser 2 is reflected by the reflector 74 and then passes through the plano-concave lens 73, the plano-convex lens 72, the dichroic mirror 71, the window 6, the air inlet chamber 12 and the air outlet 15 of the air curtain structure 1 to act on the sample to be tested;

[0044] The light source outputted by the spectrometer module 3 passes through the dichroic mirror 71 and then sequentially passes through the window 6, the air inlet chamber 12 and the air outlet 15 of the air curtain structure 1 to act on the sample to be tested; Figure 2 As shown, the light source output by the spectrometer module 3 first passes through the off-axis parabolic mirror 4 and then is reflected to the window 6 by the dichroic mirror 71, and finally acts on the sample to be tested.

[0045] As a further implementation of this embodiment, the plano-concave lens 73 or the plano-convex lens 72 is installed on the first displacement module 8, and the first displacement module 8 is driven based on a driving device, so that the first displacement module 8 can perform reciprocating linear motion between the reflector 74 and the dichroic mirror 71.

[0046] The driving module drives the first displacement module 8 to perform linear reciprocating motion between the reflector 74 and the dichroic mirror 71, so that the position of the plano-concave lens 73 or the plano-convex lens 72 can be adjusted, thereby realizing a zooming process of different focal points on the sample surface.

[0047] It should be noted that, in this embodiment, the plano-concave lens 73 and the plano-convex lens 72 can also be mounted on a first displacement module 8 respectively, so that both can be adjusted and moved by the first displacement module 8;

[0048] Furthermore, the plano-concave lens 73 and the plano-convex lens 72 can be replaced with two spherical reflectors 74 .

[0049] As a possible implementation of this embodiment, the laser 2, optical path module, spectrometer module 3 and air curtain structure 1 are all installed on the second displacement module 9. The second displacement module 9 is driven by a driving device to control the movement of the second displacement module 9, so that the air outlet 15 of the air curtain structure 1 acts on the sample to be monitored.

[0050] As a possible implementation of this embodiment, the real-time LIBS detection device further includes a sensing module 5 , which is used to detect the spatial position between the sample to be tested and the sample detection end, wherein the sensing module 5 uses an optical rangefinder.

[0051] In this embodiment, the sensing module 5 measures the overall sample height, and the control module feeds back instructions to the drive module. The drive module then drives the displacement module, which in turn moves the laser 2, optical path module, spectrometer module 3, and air curtain structure 1 until the air curtain module's air outlet 15 and the electrode rod 16 are able to act on the sample to be tested. The electrode rod 16 is inserted into the high-temperature sample for electrolysis, preventing the sample from undergoing redox reactions. Simultaneously, a protective gas is introduced into the air curtain structure 1, which, through the air curtain structure's air outlet 15, suppresses the emission of volatiles from the high-temperature sample and prevents splashing of the high-temperature sample.

[0052] Secondly, it should be noted that there are many ways to drive the first displacement module 8 and the second displacement module 9 in the mechanical field, such as the rack and pinion method, that is, a rack is installed on the displacement module, a gear is installed at the electrode output end, and a slide rod is set through the displacement module, so that the displacement module is driven to perform linear motion by the rack and pinion method; secondly, the displacement module can also be driven to move by a linear moving module, that is, the displacement module can be installed on the moving slide of the linear moving module; the above-mentioned driving methods are all conventional technical means in this field, so they will not be repeated in the present invention.

[0053] In this example, in order to verify the detection effect of the adaptive high-temperature molten sample real-time LIBS detection device, it was applied to the detection of nuclear elements in high-temperature molten salt. The detection spectrum is shown in the figure below. Figure 3 As shown, the air curtain structure 1 effectively suppresses plasma thermal background interference, improving the signal-to-noise ratio. A high-temperature molten sample with an element concentration of 0.5% exhibits a distinct characteristic peak. Furthermore, through the interaction of the sensing module 5, the optical path module 7, and the displacement module, four tests on this high-temperature molten sample were performed, with an RSD of 9.2%, effectively improving the stability of high-temperature molten sample detection.

[0054] The above are only preferred embodiments of the present application and are not intended to limit the present application. Any modifications, equivalent replacements, and improvements made within the spirit and principles of the present application should be included in the scope of protection of the present application.

Claims

1. A real-time LIBS detection device for high-temperature molten samples, characterized in that: Including laser, optical path module, spectrometer module and air curtain module; The air curtain module includes a first mounting portion and a second mounting portion, wherein a window piece is mounted on the first mounting portion and an air outlet is provided on the second mounting portion; the first mounting portion and the second mounting portion are enclosed so as to form an air inlet chamber between the first mounting portion and the second mounting portion; A laser incident channel is formed between the window, the air inlet chamber and the air outlet; and an air inlet is introduced into the air inlet chamber, wherein the air inlet area is larger than the air outlet area; The air inlet is installed on the side wall of the air inlet chamber and takes air in toward the window sheet; The air inlet chamber is funnel-shaped, and the diameter of the end close to the first mounting portion is larger than the diameter of the end close to the second mounting portion; The optical path module is provided with a spectrum incident port, a laser incident port and an output port, wherein the output port faces the window piece of the air curtain structure.

2. A high-temperature molten sample real-time LIBS detection device according to claim 1, characterized in that: The second mounting portion is provided with an electrode rod.

3. A high-temperature molten sample real-time LIBS detection device according to claim 1, characterized in that: The optical path module includes a reflector, a plano-concave lens, a plano-convex lens and a dichroic mirror; The laser light emitted by the laser is reflected by the reflector and then passes through the plano-concave lens, the plano-convex lens, the dichroic mirror, the window, the air inlet chamber and the air outlet of the air curtain structure in sequence to act on the sample to be tested; The light source output by the spectrometer module passes through the dichroic mirror, and then sequentially passes through the window, the air inlet chamber, and the air outlet of the air curtain structure to act on the sample to be tested.

4. A real-time LIBS detection device for high-temperature molten samples according to claim 3, characterized in that: The plano-concave lens or the plano-convex lens is mounted on a first displacement module. The first displacement module is driven by a driving device so that the first displacement module can perform reciprocating linear motion between the reflector and the dichroic mirror.

5. The real-time LIBS detection device for high-temperature molten samples according to claim 3, characterized in that: The laser, optical path module, spectrometer module and air curtain structure are all installed on the second displacement module. The second displacement module is driven by a driving device to control the movement of the second displacement module, so that the air outlet of the air curtain structure acts on the sample to be monitored.

6. A high-temperature molten sample real-time LIBS detection device according to claim 4 or 5, characterized in that: The real-time LIBS detection device further includes a sensing module, which is used to detect the spatial position between the sample to be tested and the sample detection end.

7. A high-temperature molten sample real-time LIBS detection device according to claim 6, characterized in that: The perception module adopts an optical rangefinder.

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