Air curtain structure for real-time LIBS (laser induced breakdown spectroscopy) detection of high-temperature molten sample and LIBS detection deviceTechnical Field
The application belongs to the technical field of analysis and detection, and particularly relates to an air curtain structure for real-time LIBS detection of a high-temperature molten sample and a LIBS detection device.
Background
The Laser-induced breakdown spectroscopy (Laser-induced breakdown spectroscopy, LIBS) technology generates local plasmas on the surface of a sample through Laser pulses, and realizes qualitative and quantitative analysis of elements through analysis of plasma emission spectra, has the characteristics of no need of complex sample preparation, capability of simultaneously detecting multiple elements, high response speed and the like, is very suitable for real-time monitoring in a high-temperature environment, and has great potential in detection of strategic elements in the high-temperature environment. At present, LIBS is successfully applied to analysis of components on the surface of a uranium fuel rod and detection of a crack product in molten salt through a specially designed optical system, remote measurement in a radioactive environment is realized, in monitoring of a metallurgical process, the LIBS system is directly arranged near a smelting furnace, on-line component analysis of high-temperature melts such as molten iron, molten aluminum and the like is realized, real-time data support is provided for optimization of smelting processes, in research of high-temperature materials, LIBS is combined with a hot table, in-situ observation of element migration behaviors of the materials in a heating process is realized, and a new view is provided for understanding a high-temperature failure mechanism of the materials.
Although LIBS systems are currently available for use with high temperature samples containing strategic elements, volatiles can contaminate the optical window when the high temperature melt samples are detected by the existing LIBS systems, resulting in laser focus drift and attenuation of the optical signal. Meanwhile, when a high-temperature sample is detected, the detection stability of trace elements is insufficient due to the interference of a plasma thermal radiation background.
Disclosure of Invention
The invention provides an air curtain structure for real-time LIBS detection of a high-temperature molten sample and a LIBS detection device, aiming at solving the technical problems that when the high-temperature molten sample is detected, volatile matters pollute an optical window, so that laser is focused and drifted, and an optical signal is attenuated.
First, the high temperature of the present invention is 200 ℃.
In one aspect, the invention provides an air curtain structure for real-time LIBS detection of a high-temperature molten sample, which comprises a first installation part and a second installation part, wherein a window sheet is arranged on the first installation part, and an air outlet is arranged on the second installation part;
And introducing an air inlet into the air inlet chamber, wherein the air inlet area is larger than the air outlet area.
According to the invention, the protective gas is introduced through the gas inlet and flows out of the gas outlet, the gas flow rate of the gas outlet is increased because the gas inlet area is larger than the gas outlet area, so that the problem that volatile matters enter the gas inlet cavity through the gas outlet to pollute the window sheet is avoided, and the contact surface can be effectively cooled because the gas flow rate of the gas outlet is increased, therefore, the flow rate of the gas outlet is increased by increasing the area ratio of the gas inlet to the gas outlet, namely, the gas inlet area is larger than the gas outlet area, and the high flow rate can not only inhibit the volatile matters of the high-temperature sample from flowing to the window sheet to influence the window sheet, but also inhibit the pollution of the window sheet caused by the fact that laser acts on the high-temperature liquid sample to splash, and can also cool the contact surface.
Preferably, the air inlet is mounted on the side wall of the air inlet chamber and is used for introducing air towards the window sheet.
Preferably, the air inlet chamber is funnel-shaped, and the diameter of one end close to the first installation part is larger than that of one end close to the second installation part.
Preferably, the second mounting portion is provided with an electrode rod.
On the other hand, the invention provides a real-time LIBS detection device for a high-temperature molten sample, which comprises 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 the high-temperature molten sample;
the light path module is provided with a spectrum entrance port, a laser entrance port and an exit port, wherein the exit port faces the window sheet of the air curtain structure.
Preferably, the optical path module includes a reflecting mirror, a plano-concave lens, a plano-convex lens, and a dichroic mirror;
After being reflected by a reflecting mirror, the laser emitted by the laser sequentially passes through a plano-concave lens, a plano-convex lens, a dichroic mirror, a window sheet, an air inlet cavity and an air outlet of an air curtain structure to act on a sample to be detected;
and a light source output by the spectrometer module sequentially passes through the window sheet, the air inlet chamber and the air outlet of the air curtain structure to act on the sample to be detected after passing through the dichroic mirror.
Preferably, the plano-concave lens or the plano-convex lens is mounted on a first displacement module, which is driven based on a driving device, so that the first displacement module can make a reciprocating linear motion between the reflecting mirror and the dichroic mirror.
Preferably, the laser, the light path module, the spectrometer module and the air curtain structure are all installed on the second displacement module, and the second displacement module is driven based on the driving device to control the second displacement module to move, so that an air outlet of the air curtain structure acts on a sample to be monitored.
Preferably, the real-time LIBS detection device further comprises a sensing module, wherein the sensing module is used for detecting the space position between the sample to be detected and the sample detection end.
Preferably, the sensing module adopts an optical distance meter.
According to the invention, the protective gas is introduced through the gas inlet and flows out of the gas outlet, the gas flow rate of the gas outlet is increased because the gas inlet area is larger than the gas outlet area, so that the problem that volatiles enter the gas inlet cavity through the gas outlet to pollute the window sheet is avoided, and the contact surface can be effectively cooled because the gas flow rate of the gas outlet is increased, therefore, the flow rate of the gas outlet is increased by increasing the area ratio of the gas inlet to the gas outlet, namely the gas inlet area is larger than the gas outlet area, the flow rate of the gas outlet is increased, the window sheet is influenced by the flow of the volatiles of a high-temperature sample, and the window sheet pollution caused by the fact that laser acts on the high-temperature liquid sample splash can be inhibited, and in addition, the contact surface can be cooled.
Drawings
In order to more clearly illustrate the technical solutions of the embodiments of the present application, the drawings that are needed in the embodiments or the description of the prior art will be briefly described below, it being obvious that the drawings in the following description are only some embodiments of the present application, and that other drawings may be obtained according to these drawings without inventive effort for a person skilled in the art.
Fig. 1 is a schematic view of an air curtain structure according to embodiment 1 of the present invention.
Fig. 2 is a schematic structural diagram of a LIBS detection device according to embodiment 3 of the present invention.
Fig. 3 is a graph showing the detection result of nuclear elements in a high-temperature molten sample provided in example 3 of the present invention.
The reference numerals illustrate 1. The air curtain structure; 11, a first mounting part; the device comprises a gas inlet chamber, a gas inlet, a second mounting part, a gas outlet, a electrode rod, a hollow part, a laser, a spectrometer module, an off-axis parabolic mirror, a sensing module, a window sheet, a light path module, a dichroic mirror, a plane convex lens, a plane concave lens, a reflecting mirror, a first displacement module, a second displacement module and a third displacement module, wherein the gas inlet chamber, the gas inlet, the second mounting part, the gas outlet, the electrode rod, the hollow part, the laser, the spectrometer module, the off-axis parabolic mirror, the sensing module, the window sheet, the light path module, the dichroic mirror, the plane convex lens, the plane concave lens, the reflecting mirror, the first displacement module and the second displacement module.
Detailed Description
In order to make the technical problems, technical schemes and beneficial effects to be solved more clear, the 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 for purposes of illustration only and are not intended to limit the scope of the application.
Example 1
The air curtain structure for the real-time LIBS detection of the high-temperature molten sample comprises a first installation part 11 and a second installation part 14, wherein a window sheet 6 is installed on the first installation part 11, and an air outlet 15 is arranged on the second installation part 14;
The window sheet 6, the air inlet chamber 12 and the air outlet 15 form a laser incidence channel, 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.
According to the invention, the shielding gas is introduced into the gas inlet 13, and flows out of the gas outlet 15 in the shielding gas, so that the gas flow rate of the gas outlet 15 is increased because the gas inlet area of the gas inlet 13 is larger than the gas outlet area of the gas outlet 15, the problem that volatiles enter the gas inlet chamber 12 through the gas outlet 15 to pollute the window sheet 6 is avoided, and the problem of pollution of an optical window can be effectively prevented, and the contact surface can be effectively cooled because the gas flow rate of the gas outlet 15 is increased, so that the flow rate of the gas outlet 15 is increased by increasing the area ratio of the gas inlet 13 to the gas outlet 15, namely the area of the gas inlet 13 is larger than the area of the gas outlet 15, the flow rate of the gas outlet 15 is increased, and the high flow rate can not only inhibit the flow of high-temperature sample volatiles to the window sheet 6 to influence the window sheet 6, but also inhibit the pollution of the window sheet 6 caused by the splashing of laser acting on the high-temperature liquid sample.
In this embodiment, the window 6 may be fitted into the first mounting portion 11, and a hollow portion 17 corresponding to the size of the window 6 may be provided in the first mounting portion 11, and the window 6 may be mounted in the hollow portion 17.
As shown in fig. 1, as a further implementation manner of this embodiment, the air inlet 13 is installed on a side wall of the air inlet chamber 12 and is used for introducing air toward the window sheet 6, in this embodiment, the air inlet 13 is used for introducing air toward the window sheet 6, so that the protective air blown by the air inlet 13 directly acts on the window sheet 6, and after passing through the effect of the window sheet 6, the air flow enters the air outlet 15, thereby further avoiding the pollution of the window sheet 6.
As the funnel-shaped air inlet chamber 12 is adopted, a flow guiding effect caused by pressure and a chamber inner wall structure is formed in the air inlet chamber 12, and air is guided to the air outlet 15, so that the pollution of the window sheet 6 is further avoided;
As one possible implementation manner of this embodiment, the second mounting portion 14 is provided with two electrode rods 16, where the two electrode rods 16 are disposed at 180 ° intervals with respect to the center of the air outlet 15, and the high-temperature sample is electrolyzed by the electrode rods 16 to prevent the oxidation-reduction reaction of the sample.
Example 2
The difference between this embodiment 2 and embodiment 1 is that the air inlet 13 is set in a range of 4-8mm, the diameter of the air inlet 13 is set in a range of 50-75mm, the diameter of the air outlet 15 is 10-15mm, and the air inlet area of the air inlet 13 is significantly smaller than the air outlet area of the air outlet 15, but since the air inlet 13 faces the window sheet 6 and the window sheet 6 is located at the top end of the air inlet chamber 12 and the area thereof is much larger than the area of the air outlet 15, the air inlet 13 is actually a quick connector in this embodiment, and the top end of the air inlet chamber 12 forms the large area air inlet, thereby making the area of the air inlet larger than the area of the air outlet, and increasing the flow rate of the air outlet 15.
For the technical solutions of the two embodiments 1 and 2, it should be noted that the present application only needs to ensure that the area of the air inlet portion is larger than the area of the air outlet portion, or that the cross-sectional area of the air inlet portion is gradually reduced to the air outlet portion, and the joint portion is not counted, and the joint is only for causing the shielding gas. That is, in embodiment 2, the intake air is formed by the intake port 13 and the top end of the intake chamber 12, and the actual intake air area is the top end of the intake chamber 12, so that the intake air area is larger than the outlet air area.
Example 3
The invention relates to a real-time LIBS detection device for a high-temperature molten sample, which comprises a laser 2, an optical path module 7, a spectrometer module 3 and an air curtain module, wherein the air curtain module adopts an air curtain structure 1 for real-time LIBS detection of the high-temperature molten sample;
The light path module 7 is provided with a spectrum entrance, a laser entrance and an exit, wherein the exit is directed towards the window sheet 6 of the air curtain structure 1.
As one possible implementation of the present embodiment, the optical path module includes a reflecting mirror 74, a plano-concave lens 73, a plano-convex lens 72, and a dichroic mirror 71;
After being reflected by the reflecting mirror 74, the laser light emitted by the laser 2 sequentially passes through the plano-concave lens 73, the plano-convex lens 72, the dichroic mirror 71, the window sheet 6, the air inlet chamber 12 and the air outlet 15 of the air curtain structure 1 to act on a sample to be detected;
The light source output by the spectrometer module 3 sequentially passes through the window sheet 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 after passing through the dichroic mirror 71, and the light source output by the spectrometer module 3 firstly passes through the off-axis parabolic mirror 4 and then is reflected to the window sheet 6 through the dichroic mirror 71 to act on the sample to be tested as shown in fig. 2.
As a further implementation of the present embodiment, the plano-concave lens 73 or the plano-convex lens 72 is mounted 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 make a reciprocating linear motion between the reflecting mirror 74 and the dichroic mirror 71.
The driving module drives the first displacement module 8 to do linear reciprocating motion between the reflecting mirror 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, and the zooming process of different focuses on the surface of the sample can be further realized.
It should be noted that, in the present embodiment, the plano-concave lens 73 and the plano-convex lens 72 may also be respectively mounted on one first displacement module 8, so that both may be adjusted and moved by the first displacement module 8;
and the plano-concave lens 73 and the plano-convex lens 72 may be replaced with two spherical mirrors 74.
As a possible implementation manner of this embodiment, the laser 2, the optical path module, the spectrometer module 3 and the air curtain structure 1 are all installed on the second displacement module 9, and the second displacement module 9 is driven based on the 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.
As a possible implementation manner of this embodiment, the real-time LIBS detection device further includes a sensing module 5, where the sensing module 5 is configured to detect a spatial position between a sample to be detected and a sample detection end, and the sensing module 5 adopts an optical range finder.
In the embodiment, the whole height of the sample is measured through the sensing module 5, the instruction is fed back to the driving module through the control module, the driving module drives the displacement module to drive the laser 2, the light path module, the spectrometer module 3 and the air curtain structure 1 to move until the air outlet 15 of the air curtain module and the electrode rod 16 can act on the sample to be measured, and the electrode rod 16 is inserted into the high-temperature sample for electrolysis, so that the sample is prevented from undergoing oxidation-reduction reaction. Meanwhile, the air curtain structure 1 is filled with protective gas, and the protective gas inhibits volatile matters of the high-temperature sample through the air outlet 15 of the air curtain structure 1. And prevents high temperature samples from splashing.
It should be noted that, for driving the first displacement module 8 and the second displacement module 9, there are various manners in the mechanical field, such as a manner of gear and rack, that is, a manner of installing a rack on the displacement module, installing a gear at an electrode output end, and penetrating a slide bar on the displacement module, so that the displacement module is driven to do linear motion by the manner of gear and rack, and then the displacement module can be driven to move by the linear movement module, that is, the displacement module is installed on a moving sliding table of the linear movement module, and for the driving manner, the conventional technical means in the field are adopted, so that the invention is not repeated.
In this embodiment, to verify the detection effect of the real-time LIBS detection device for the self-adaptive high-temperature molten sample, it is applied to the detection of the nuclear element in the high-temperature molten salt. The detection spectrum diagram is shown in figure 3, and through the air curtain structure 1, the plasma thermal background interference is effectively inhibited, the signal to noise ratio is improved, and a high-temperature melting sample with the element concentration of 0.5% has obvious characteristic peaks. Meanwhile, the sensing module 5, the light path module 7 and the displacement module are matched with each other to detect the high-temperature molten sample for 4 times, the RSD is 9.2%, and the detection stability of the high-temperature molten sample is effectively improved.
The foregoing description of the preferred embodiments of the application is not intended to be limiting, but rather is intended to cover all modifications, equivalents, and alternatives falling within the spirit and principles of the application.