CN214408699U

CN214408699U - Micro nitrogen analyzer based on plasma emission spectrum

Info

Publication number: CN214408699U
Application number: CN202120563842.3U
Authority: CN
Inventors: 徐华江; 王志伟; 姜培刚
Original assignee: Beijing Taihe Lianchuang Technology Co ltd
Current assignee: Beijing Taihe Lianchuang Technology Co ltd
Priority date: 2021-03-18
Filing date: 2021-03-18
Publication date: 2021-10-15
Anticipated expiration: 2031-03-18

Abstract

The application relates to a trace nitrogen analyzer based on plasma emission spectrum, including: the device comprises a supporting seat, an ionization cavity, a driving module, a driving electrode, an optical filter and a receiving module; the support seat is provided with a groove, and the ionization cavity is arranged in the groove of the support seat; the ionization cavity is a hollow structure with openings at two ends, and the side walls at two ends of the groove are respectively provided with an air inlet channel and an air outlet channel; two ends of the ionization cavity are respectively arranged in the air inlet channel and the air outlet channel and are communicated with the air inlet channel and the air outlet channel; the driving electrode is arranged on the outer side wall of the ionization cavity and is electrically connected with the driving module; the optical filter and the receiving module are both arranged on the supporting seat, and the optical filter is positioned beside the air outlet channel and faces the opening of the ionization cavity; the receiving module is positioned at the rear end of the optical filter. The spectrum generated by the excitation of the ionized gas can directly penetrate through the optical filter to the detector through the opening of the ionization cavity without penetrating through a layer of glass, so that the detection sensitivity is effectively improved.

Description

Micro nitrogen analyzer based on plasma emission spectrum

Technical Field

The application relates to the technical field of gas analysis and measurement, in particular to a micro-nitrogen analyzer based on plasma emission spectrum.

Background

In air separation production, the content of trace agricultural nitrogen in refined argon is often required to be monitored on line. The determination of trace nitrogen content is also required in high purity argon quality monitoring. Therefore, the detection of trace nitrogen in argon becomes a main monitoring project for air separation production. At present, there are two kinds of analyzers for analyzing trace nitrogen in argon, one of them is to use the relative movement characteristic of ions, the gas entering the measuring chamber is ionized by the weak radioactive source of the built-in measuring chamber, the moving argon ions and nitrogen ions generate difference, and the difference can be measured by electronic means to measure the content of nitrogen contained in argon. The other method is based on plasma emission spectroscopy, a high-frequency voltage power supply is adopted to act on gas in an ionization cell, and the gas (argon and nitrogen) is ionized to generate free electrons and positive ions, so that a plasma environment is formed. The positive charge ions and the free electrons are accelerated to move to the negative electrode and the positive electrode respectively under the action of an electric field. Due to the collisions, the ions and electrons transfer their own energy to the atoms, so that the sample gaseous atoms are excited. After the atoms are excited, the outer layer electrons of the atoms generate energy level transition, a characteristic spectrum is emitted when the atoms return to the ground state, and the concentration of trace impurity gas is analyzed through detecting the characteristic spectrum. However, when the second method is used for detecting and analyzing trace nitrogen, an integrally formed glass cavity is usually used, and the emitted light needs to penetrate through the glass and then reach the detection unit, which causes a certain energy loss and accuracy of the final analysis result of the image.

SUMMERY OF THE UTILITY MODEL

In view of this, the present application provides a trace nitrogen analyzer based on plasma emission spectroscopy, which can effectively improve the accuracy of an analysis result.

According to an aspect of the present application, there is provided a trace nitrogen analyzer based on plasma emission spectroscopy, including: the device comprises a supporting seat, an ionization cavity, a driving module, a driving electrode, an optical filter and a receiving module;

the support seat is provided with a groove, and the ionization cavity is arranged in the groove of the support seat;

the ionization cavity is of a hollow structure with openings at two ends, and the side walls at two ends of the groove are respectively provided with an air inlet channel and an air outlet channel;

two ends of the ionization cavity are respectively arranged in the air inlet channel and the air outlet channel and are communicated with the air inlet channel and the air outlet channel, so that the gas to be detected enters the ionization cavity through the air inlet channel and is discharged from the air outlet channel after being ionized in the ionization cavity;

the driving electrode is arranged on the outer side wall of the ionization cavity, is electrically connected with the driving module and is used for generating an electric field under the driving of the driving module;

the optical filter and the receiving module are both arranged on the supporting seat, and the optical filter is positioned beside the air outlet channel and faces the opening of the ionization cavity;

the receiving module is located at the rear end of the optical filter and used for receiving the optical signal filtered by the optical filter and converting the optical signal into an electrical signal.

In a possible implementation manner, the system further comprises a flow controller; the flow controller is positioned beside the supporting seat, is arranged on a gas pipeline connected with the gas inlet channel of the supporting seat and is used for controlling the flow of the measured gas flowing into the ionization cavity through the gas inlet channel.

In a possible implementation manner, the ionization cavity is realized by sequentially connecting a plurality of insulating plates to form a cavity with a hollow structure.

In a possible implementation manner, the number of the insulating plates is four, and the four insulating plates are sequentially bonded to form a hollow structure with openings at two ends.

In one possible implementation, the driving electrodes are disposed on the upper and lower surfaces of the ionization chamber.

In one possible implementation, the filter is an ultraviolet narrowband filter.

In a possible implementation manner, the supporting seat is in a U-shaped structure; the ionization cavity is transversely arranged in the U-shaped groove of the supporting seat;

the air inlet channel and the air outlet channel are respectively arranged in the U-shaped side walls at the two ends of the supporting seat;

the air inlet channel and the ionization cavity are coaxially arranged, the air outlet channel is L-shaped, and an air outlet of the air outlet channel is arranged downwards;

the optical filter is positioned at the side of the air outlet channel, and the side wall of the air outlet channel adjacent to the optical filter is provided with a through hole.

In a possible implementation manner, the ionization chamber is made of any one of glass and ceramic.

In one possible implementation, the driving electrode is a conductive sheet;

the conducting strip is pasted on the outer side wall of the ionization cavity.

In one possible implementation, the drive electrode is a copper wafer.

The ionization cavity used for ionizing the gas to be detected is set to be a cavity with two open ends and a hollow structure, a supporting seat is arranged corresponding to the cavity in a matched mode, an air inlet channel and an air outlet channel used for communicating the ionization cavity are arranged on the supporting seat, therefore, when the gas to be detected is subjected to trace nitrogen detection and analysis based on plasma emission spectrum, the spectrum generated by gas excitation after ionization can directly pass through an opening transmission optical filter of the ionization cavity to a detector, one layer of glass does not need to pass through, the spectrum generated after ionization can less penetrate through one layer of material, the transmittance is also improved, the detection sensitivity is finally effectively improved, and the accuracy of a detection result is guaranteed.

Other features and aspects of the present application will become apparent from the following detailed description of exemplary embodiments, which proceeds with reference to the accompanying drawings.

Drawings

The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate exemplary embodiments, features, and aspects of the application and, together with the description, serve to explain the principles of the application.

Fig. 1 shows a schematic structural diagram of a micro nitrogen analyzer based on plasma emission spectroscopy according to an embodiment of the present application.

Detailed Description

Various exemplary embodiments, features and aspects of the present application will be described in detail below with reference to the accompanying drawings. In the drawings, like reference numbers can indicate functionally identical or similar elements. While the various aspects of the embodiments are presented in drawings, the drawings are not necessarily drawn to scale unless specifically indicated.

The word "exemplary" is used exclusively herein to mean "serving as an example, embodiment, or illustration. Any embodiment described herein as "exemplary" is not necessarily to be construed as preferred or advantageous over other embodiments.

Furthermore, in the following detailed description, numerous specific details are set forth in order to provide a better understanding of the present application. It will be understood by those skilled in the art that the present application may be practiced without some of these specific details. In some instances, methods, means, elements and circuits that are well known to those skilled in the art have not been described in detail so as not to obscure the present application.

Fig. 1 shows a schematic structural diagram of a micro nitrogen analyzer 100 based on plasma emission spectroscopy according to an embodiment of the present application. As shown in fig. 1, the micro nitrogen analyzer 100 includes: the plasma processing apparatus comprises a support base 110, an ionization chamber 120, a driving module 130, a driving electrode 140, an optical filter 150 and a receiving module 160. Wherein, the support base 110 has a groove, and the ionization chamber 120 is installed in the groove of the support base 110. The ionization chamber 120 is a hollow structure with two open ends, and the side walls of the two ends of the groove are respectively provided with an air inlet channel 111 and an air outlet channel 112. Two ends of the ionization chamber 120 are respectively disposed in the inlet channel 111 and the outlet channel 112, and are communicated with the inlet channel 111 and the outlet channel 112, so that the gas to be detected enters the ionization chamber 120 through the inlet channel 111, and is discharged from the outlet channel 112 after being ionized in the ionization chamber 120. The driving electrode 140 is installed on an outer sidewall of the ionization chamber 120 and electrically connected to the driving module 130 for generating an electric field under the driving of the driving module 130. The optical filter 150 and the receiving module 160 are both mounted on the supporting base 110, and the optical filter 150 is located beside the air outlet channel 112 and faces the opening of the ionization chamber 120. The receiving module 160 is located at the rear end of the optical filter 150, and is configured to receive the optical signal filtered by the optical filter 150 and convert the optical signal into an electrical signal.

From this, the trace nitrogen analysis appearance 100 of this application embodiment, when carrying out trace nitrogen analysis to the gas of being surveyed and detecting, ionization cavity 120 through being used for the ionization gas of being surveyed sets up to the cavity of both ends open-ended hollow structure, and set up a supporting seat 110 corresponding to this cavity is supporting, set up inlet channel 111 and outlet channel 112 that are used for communicateing ionization cavity 120 on this supporting seat 110, when carrying out trace nitrogen detection and analysis to the gas of being surveyed based on plasma emission spectrum from this, the spectrum that the gas after the ionization arouses the production can directly pass through ionization cavity 120's opening transmission optical filter 150 to the detector, need not pass one deck glass again, this spectrum that just makes the production after the ionization less pierces through one deck material, thereby also improved the transmissivity, finally effectively improved detection sensitivity, the degree of accuracy of testing result has been guaranteed.

Because the fluctuation of the gas flow can affect the measurement result, in the micro nitrogen analyzer 100 according to the embodiment of the present application, before the measured gas enters the gas inlet channel 111 of the support base 110, a flow controller 170 may be disposed on the gas pipeline connected to the gas inlet channel 111, and the gas flow in the gas pipeline is controlled by the flow controller 170, so that the gas in the gas pipeline tends to be stable and then enters the gas inlet channel 111 of the support base 110, and flows into the ionization chamber 120 through the gas inlet channel 111.

In one possible implementation, flow controller 170 may be implemented using commercially available high precision, high quality flow controllers 170 to ensure efficient control of gas flow.

Further, the ionization chamber 120 may be implemented by sequentially bonding a plurality of insulating plates to form a hollow structure with openings at two ends. The number of the insulating plates may be three, four, or more than four, so long as the driving electrode 140 disposed on the outer sidewall of the ionization chamber 120 can generate an ionization electric field under the driving of the driving module 130. Preferably, four insulating plates are sequentially bonded to form a cavity tube with a hollow structure.

That is, arrange four insulating boards according to upper and lower, left and right position in proper order, then carry out sealing connection with every two adjacent insulating boards, if: bonding may be used.

For example, two large glass plates, an upper large glass plate and a lower large glass plate, and a left barrier glass and a right barrier glass can be used to form a cavity tube with a hollow structure by bonding. Wherein, the formed cavity tube can be a hollow cuboid tubular structure.

Meanwhile, it should be noted that the ionization chamber 120 may be made of glass or ceramic or other insulating dielectric materials. The material is not specifically limited here.

Through adopting the polylith insulation board to bond in proper order and form both ends open-ended cavity tubulose cavity for the combination bonds formula cavity and makes things convenient for the regulation of drive electrode 140 distance between the piece, thereby can adjust the intensity of drive electric field according to the measuring gas adaptability of difference, improves the measuring flexibility, makes the trace nitrogen analysis appearance 100 of this application embodiment can be applicable to and measure different detecting gas.

It should be further explained that, when the ionization chamber 120 adopts a mode of bonding a plurality of insulating plates, the bonding blocks used are integrated bonding blocks, so as to avoid the conditions that the bonding blocks at two ends of the same type of product are independent, the stress at two ends is uneven during installation, the insulating plates are broken, the sealing is poor, and the like.

Also, the mounting of the ionization chamber 120 on the support base 110 is also sealed. That is, the connection between the openings at the two ends of the ionization chamber 120 and the inlet channel 111 and the outlet channel 112 of the support base 110 is also sealed to prevent air leakage. The sealing means used may be a sealing structure conventional in the art, and is not particularly limited herein.

In addition, the driving electrodes 140 may be disposed on the upper and lower surfaces of the ionization chamber 120. The driving motor is electrically connected with the driving module 130, and a high-frequency amplitude modulation oscillation electric field is applied to the driving electrode 140 by the driving module 130, so that sufficient energy is provided for stable excitation and ionization of the gas to be detected.

The driving electrode 140 may be fixedly disposed on an outer sidewall of the ionization chamber 120 in an adhesive manner, or may be fixedly mounted in other manners, which is not specifically limited herein. Meanwhile, the driving module 130 may be implemented by a device conventional in the art, and is not particularly limited herein.

Further, the driving electrode 140 may be directly implemented by using a conductive sheet. Such as: the copper wafer can be adopted, or other excellent conductor metal materials can be adopted, the detected gas is ionized in the cavity where the driving electrode 140 is located, the impurity gas is excited to emit a spectrum, the emitted spectrum is directly filtered by the optical filter 150 through the opening of the ionization cavity 120, and then the optical signal is converted into the electrical signal by the receiving module 160 from the receiving module 160.

In addition, referring to fig. 1, in the micro nitrogen analyzer 100 according to the embodiment of the present application, the supporting base 110 may be configured as a U-shaped base, and the ionization chamber 120 is transversely installed in a U-shaped groove of the supporting base 110. The air inlet channel 111 and the air outlet channel 112 are respectively arranged in the U-shaped side walls at two ends of the supporting base 110. The air inlet channel 111 and the ionization chamber 120 are coaxially arranged, the air outlet channel 112 is L-shaped, and an air outlet of the air outlet channel 112 is arranged downward. The optical filter 150 is located beside the air outlet channel 112, and the side walls of the air outlet channel 112 adjacent to the optical filter 150 are through holes.

Therefore, the gas to be detected can directly enter the ionization cavity 120 through the gas inlet channel 111 in the support base 110, and then is ionized under the electric field generated by the driving electrode 140, so as to excite the impurity gas to emit a spectrum, and further enters the gas outlet channel 112 through the opening of the ionization cavity 120, and is filtered by the optical filter 150, the optical filter 150 selects the light with a specific wavelength corresponding to the nitrogen in the generated spectrum signal, so as to filter the spectrum emitted by other backgrounds, and after the influence of the impurity spectrum is eliminated, the filtered light signal is received by the receiving module 160. The receiving module 160 converts the optical signal into an electrical signal, and the signal processor analyzes and processes the received electrical signal, thereby detecting and analyzing the nitrogen content. The receiving module 160 may use a high-sensitivity ultraviolet photodiode to detect the nitrogen characteristic spectral line intensity, so as to implement photoelectric conversion.

In one possible implementation, the filter 150 may be implemented using an ultraviolet narrowband filter 150.

It should be noted that, although the trace nitrogen analyzer 100 based on plasma emission spectroscopy as described above is described by way of example in fig. 1, those skilled in the art will appreciate that the present application should not be limited thereto. In fact, the user can flexibly set the structures of the parts according to personal preference and/or practical application scenarios, as long as the spectrum generated after ionization can be directly transmitted to the optical filter 150 without passing through the sidewall of the ionization chamber 120.

Having described embodiments of the present application, the foregoing description is intended to be exemplary, not exhaustive, and not limited to the disclosed embodiments. Many modifications and variations will be apparent to those of ordinary skill in the art without departing from the scope and spirit of the described embodiments. The terms used herein were chosen in order to best explain the principles of the embodiments, the practical application, or technical improvements to the techniques in the marketplace, or to enable others of ordinary skill in the art to understand the embodiments disclosed herein.

Claims

1. A trace nitrogen analyzer based on plasma emission spectroscopy, comprising: the device comprises a supporting seat, an ionization cavity, a driving module, a driving electrode, an optical filter and a receiving module;

2. The micro nitrogen analyzer of claim 1, further comprising a flow controller; the flow controller is positioned beside the supporting seat, is arranged on a gas pipeline connected with the gas inlet channel of the supporting seat and is used for controlling the flow of the measured gas flowing into the ionization cavity through the gas inlet channel.

3. The trace nitrogen analyzer according to claim 1, wherein the ionization chamber is formed by sequentially connecting a plurality of insulating plates to form a hollow chamber.

4. The trace nitrogen analyzer according to claim 3, wherein the number of the insulating plates is four, and the four insulating plates are sequentially bonded to form a hollow structure having both ends open.

5. The trace nitrogen analyzer according to any one of claims 1 to 4, wherein the driving electrodes are provided on upper and lower surfaces of the ionization chamber.

6. The trace nitrogen analyzer according to claim 1, wherein the filter is an ultraviolet narrowband filter.

7. The trace nitrogen analyzer according to claim 1, wherein the support base is of a U-shaped structure; the ionization cavity is transversely arranged in the U-shaped groove of the supporting seat;

8. The trace nitrogen analyzer according to claim 1, wherein the ionization chamber is made of any one of glass and ceramic.

9. The micro nitrogen analyzer according to claim 1, wherein the driving electrode is an electrically conductive sheet;

the conducting strip is pasted on the outer side wall of the ionization cavity.

10. The micro nitrogen analyzer of claim 9, wherein the drive electrode is a copper wafer.