RU219452U1 - MULTI-COMPONENT GAS ANALYZER FTIRGAS 22 - Google Patents

Abstract

The utility model relates to analytical instrumentation and can be used to measure the content of gaseous substances and their identification. The multicomponent gas analyzer includes a housing, a pump, a power supply unit, a processor, a gas path, pressure and temperature sensors, and a measuring module. In this case, the measuring module includes fittings for gas inlet and outlet and analytical cells in the form of an oxygen sensor and a Fourier spectrometer. In addition, the multicomponent gas analyzer additionally contains a temperature control unit that provides the possibility of heating the gas path and analytical cells of the measuring module. The advantages of the utility model are to ensure continuous selection and pumping of the analyzed medium through the gas analyzer with continuous automatic and simultaneous measurement of the content of components such as SO ₂ , NO, NO ₂ , CO, HF, HCl, NH ₃ , N ₂ O, CO ₂ , CH ₄ , CH ₂ O, including H ₂ O and O ₂ , and the implementation of continuous environmental and technological control.

Description

The claimed utility model relates to analytical instrumentation and can be used to measure the content of gaseous substances and their identification. The multi-component gas analyzer FTIRGAS 22 can be used in various industries such as metallurgy, production of building materials, light and food industries, chemical and petrochemical industries, mechanical engineering and power industry, for quality control of technological processes, monitoring of gas concentrations in the air of the working area for personnel protection, as well as for monitoring the amount of greenhouse gas emissions into the atmosphere.

A gas correlation analyzer is known from the Prior Art, which contains an optically coupled modulator, correlation and comparison cuvettes, an optical system and a radiation receiver unit, as well as a synchronization unit and a signal processing unit, the control input of which is connected to the modulator through the synchronization unit. In addition, it includes a reference emitter unit optically connected to the modulator, as well as a separation unit, a sampling-comparison unit and a control unit, while the output of the radiation receiver unit is connected to the input of the separation unit, the first and second outputs of which are connected respectively to the first and second inputs of the sampling-comparison unit and the signal processing unit, the output of the sampling-comparison unit is connected through the control unit to the control input of the separation unit, and its control input is connected to the synchronization unit (see Fig. patent of the Russian Federation No. 2035717 C1, published on May 20, 1995, IPC class G01N 21/61).

Also known from the "Prior Art" is a multi-sensor gas analyzer, which contains a sampling tool, a detection device, an analytical processor, an exhaust part and a power source. The sampling means includes a sampling head and provides pre-treatment of the gas sample, in addition to sampling the gas, additionally performs pressure regulation, temperature reduction, dust removal, liquid removal. The sampling means is configured to stabilize the gas phase and/or filter a specific component; the detection device provides the measurement. The analysis processor processes the information received from the multi-sensor detection device with the help of data processing software and outputs information about the components. Power is supplied from the battery. The combined analytical system performs qualitative and/or quantitative multi-sensor analysis using multi-element analysis technology (see patent CN 101587068 B, publ. 03/28/2012, IPC: G01N 21/35; G01N 25/66; G01D 21/02).

The technical problem lies in the fact that the known devices are limited in the type and number of simultaneously analyzed gaseous compounds and are not able to operate in a continuous mode.

The objective of the present utility model is to solve the above technical problem.

The technical result consists in ensuring continuous selection and pumping of the analyzed medium through the gas analyzer with continuous automatic and simultaneous measurement of the content of components such as SO ₂ , NO, NO ₂ , CO, HF, HCl, NH ₃ , N ₂ O, CO ₂ , CH ₄ , CH ₂ O, including H ₂ O and O ₂ , and the implementation of continuous environmental and technological control.

The technical result is ensured by the fact that the multicomponent gas analyzer includes a housing, a filter, a distributed unit, a pump, a power supply unit, a board, a gas path, pressure and temperature sensors, and a measuring module. In this case, the measuring module includes fittings for gas inlet and outlet and analytical cells in the form of an oxygen sensor and a Fourier spectrometer. In addition, the multicomponent gas analyzer additionally contains a temperature control unit that provides the possibility of heating the gas path and analytical cells of the measuring module and the possibility of analyzing gases with a high content of water vapor.

In accordance with particular cases of implementation of the device may have the following features.

The gas analyzer is configured to supply the analyzed gas to the inlet fitting and pass it to the Fourier spectrometer through the oxygen sensor, while the measuring module includes three combined inlet fittings forming a heated manifold, and one gas outlet fitting.

The pump in the form of an ejection type pump is installed in the measuring module, which also contains a heated gas discharge line and pressure and temperature sensors.

Analytical cells are configured to transmit measurement signals to a personal computer.

The gas analyzer is configured to operate with a sampling probe and a sampling line that provides the possibility of transporting a gas sample from the sampling probe to the gas analyzer inlet and maintaining the gas sample temperature above the water dew point or acid dew point.

The gas analyzer is made in the form of a measuring module, which makes it possible to install it in a gas analytical cabinet.

The oxygen sensor is made in the form of a cell based on zirconium dioxide, and the Fourier spectrometer contains a Michelson interferometer.

Two fittings for inlet are made with the possibility of supplying a calibration gas mixture to them.

The essence of this utility model is illustrated by the following illustrations:

Fig. 1 - diagram of the pneumatic connection of the gas analyzer, in accordance with a particular case of its implementation;

Fig. 2 - scheme for obtaining spectra;

Fig. 3 is a functional diagram of the oxygen measurement process.

The multicomponent gas analyzer 1 includes a housing in which a pump 2, an AC power supply, boards for processing measurement information, a gas path and a measuring module 3 are installed, containing fittings for inlet 4 (counting from the top - Inlet 1, Inlet 2 and Inlet 3) and gas outlet 5 and analytical cells in the form of an oxygen sensor 6 and a Fourier spectrometer 7. The oxygen sensor 6 is made in the form of a cell based on zirconium dioxide, and the Fourier- spectrometer 7 contains a Michelson interferometer.

In addition, the multicomponent gas analyzer 1 additionally contains a temperature control unit, consisting of heating elements enclosed in a thermally insulating material, which provides the possibility of heating the gas path and analytical cells of the measuring module 3. To preserve the representativeness of the sample and conduct a correct analysis, all elements of the gas analyzer 1 in contact with the sample are heated to a temperature of 15-20°C above the level of the acid dew point (usually from +185°C to +220°C), including the analytical cells of the gas analyzer 1.

The gas analyzer 1 is configured to supply the analyzed gas to the inlet fitting 4 and its passage to the Fourier spectrometer 7 through the oxygen sensor 6, while the measuring module 3 includes three combined inlet fittings 4 forming a heated manifold, and one fitting for the gas outlet 5.

The pump 2 is made in the form of an ejection type pump and is installed in the measuring module 3, which also includes a heated line for gas discharge and pressure sensors 8 and temperature 9. The sampling method is forced, due to the ejector pump 2 built into the measuring module.

The gas analyzer 1 can be made with a heated sampling probe 10 and a filter element 11 and a sampling line (as structural elements). Sampling probe 10 is designed for sampling the analyzed gas from gas ducts and pipes, including samples with a high content of water vapor, suspended particles and corrosive components, filtering suspended particles. The sampling line transports the gas sample from the sampling probe 10 to the inlet of the gas analyzer 1 and maintains the sample temperature above the water dew point or acid dew point. The gas analyzer 1 with the sampling probe 10 and the sampling line can be used as gas analytical measuring channels of automated information-measuring industrial emissions control systems (AIS).

Two of the three fittings for inlet 4 are made with the possibility of supplying a calibration gas mixture to them from a cylinder with a calibration gas mixture 12.

Gas analyzers provide the following functions:

- continuous measurement of the content of the determined components in the analyzed gaseous medium;

- collection, processing, visualization, storage of the obtained data, presentation of the results in various formats;

- transmission upon request of the accumulated information to external means of data fixation (remote computer, server, process control system, etc.) via the Modbus TCP interface or optionally (4-20) mA.

The table shows the technical parameters of the gas analyzer.

Table Parameter Meaning Gas analyzer (multicomponent gas analyzer FTIRGAS 22) Mains AC supply voltage 230 (±10%), V Maximum power consumption of the gas analyzer 3.0 kW Maximum electrical power consumption of sampling probe and sampling line 17 kW Frame Material - sheet steel, powder coating.
Dimensions - depending on version
Protection - IP 30 or IP 54 kW (depending on version)
Weight - up to 300 kg, depending on the version Ambient temperature To achieve maximum accuracy, thermal stabilization of the measuring module is required ± 1.0 ° С Measuring module (IR-Fourier spectrometer) casing Material - sheet steel, powder coating.
Dimensions (W × H × D), mm - 610 × 590 × 450
Protection - IP 30,
Weight - up to 67 kg depending on the configuration Mains AC supply voltage 230 (±10%), V Power up to 450 W Working mode 100% of the time (continuous) Ambient temperature From +15°C to +25°C,
relative humidity - up to 80%
Thermal stabilization of ± 1.0°C is required for maximum accuracy Spectral range, cm ^-1 800-7500 Spectrum working area, cm ^-1 : 800-7500 Spectral resolution, cm ^-1 : 0.5-8.0 Measuring cell temperature up to 220°C, typ. 190°C Light path length in the measuring cell standard ~ 4.8 meters beam splitter KBr coated with Ge or BaF2 glass BaF2 or KBr Radiation source High temperature cermet or MST Detector Pyro receiver DLATGS or LiTaO3

The gas analyzer 1 implements a design based on the principles of Fourier spectrometry. The principle of measuring the concentration of gas components is based on the absorption of infrared light by various substances. An infrared beam passes through the gas to be measured, and its intensity decreases as a result of absorption at a certain wavelength, which serves as an indication of the concentration of this substance. The scheme for implementing the principle of spectroscopy is shown in Fig. 2. Infrared light is first reflected by a spherical mirror located at the input section of the analytical cell and transmitted to the second mirror. Thanks to the variable number of reflections by the three mirrors, the light path is up to 5 m.

The main element of the optical scheme of the Fourier spectrometer 7 is a two-beam Michelson interferometer, consisting of a semitransparent beam splitter and two flat mirrors. The Fourier spectrometer 7 makes it possible to obtain information about the spectral composition of IR radiation and, consequently, about the optical properties of the studied gas samples.

The spectrum acquisition scheme is shown in Fig. 2. Radiation from the emitter falls on the translucent surface of the beam splitter and is split into two beams. After reflection from the corresponding mirrors of the interferometer, the radiation of the two beams is added at the beam splitter and directed to the detector, which converts it into an electrical signal. If one of the mirrors of the two-beam Michelson interferometer is moved, then the optical path for the corresponding beam will change, and at the receiving point the radiation intensity will change due to the interference of the beams reflected from the moving and stationary mirrors.

The dependence of the recorded signal I(x) on the optical beam path difference in the interferometer x is called the interferogram. The maximum of the interferogram signal corresponds to zero path difference, since in this case all the spectral components of the beam radiation come to the receiving point in phase. The interferogram contains information about the spectral composition of the radiation. The intensity spectrum S(σ) is obtained using the inverse Fourier transform of the interferogram:

where σ is the wave number, x _max is the maximum optical path difference. The intensity spectrum depends on the spectrum of the emitter, the spectral characteristics of the elements of the optical scheme of the Fourier spectrometer 7 and the detector.

The transmission spectrum is calculated as the ratio of the intensity spectrum of the radiation transmitted through the sample S(σ) to the intensity spectrum of the radiation incident on the sample S ₀ (σ):

and is a characteristic that depends only on the properties of the sample under study, the transmission is usually expressed in%. From the transmission value, you can determine the optical density:

In chemical applications, optical density is usually calculated as a decimal logarithm, in physical applications - as a natural one.

If the Bouguer-Lambert-Beer law is satisfied, then from the transmission value, the absorption index (coefficient) a can be calculated from the ratio:

For a sample in the form of a plane-parallel plate, the material of which differs from the environment in terms of the refractive index, the absorption index is calculated from the ratio that takes into account multiple reflections from the sample surfaces:

where R is the reflection coefficient from the sample surface.

Oxygen measurements are made using a zirconia cell. Inside this cell, the measured gas is separated from the reference (atmospheric air) by passing through the zirconium membrane. Depending on the partial pressure of oxygen, oxygen ions penetrate this membrane, creating a potential difference.

The applied oxygen sensor 6 includes outlet 13, electrolyzer 14 with electrolyte pumping, which creates a constant oxygen concentration in the measuring cell 15, reference medium 16 and heater 17. Due to the known dependence of the signal on concentration, high measurement accuracy is achieved. The functional diagram of the oxygen measurement process is shown in FIG. 3.

The gas analyzer 1 generates a measuring signal, taking into account all the necessary compensations. The measured data is transmitted via the Modbus TCP protocol, or displayed on a personal computer monitor, or as an analog output signal (4-20) mA. The gas analyzer can be controlled by a personal computer.

In accordance with a particular case of execution, the gas analyzer 1 is made in the form of a module that makes it possible to install it in a gas analytical cabinet. In this case, the gas analyzer 1 is a part of the measuring system, which includes the following main components:

- analytical cabinet with control panel (personal computer with touch screen);

- sampling probe 10;

- heated sampling line;

- gas outlet: PTFE pipeline (optional: heated exhaust pipeline);

- the heated collector allows to make parallel sampling on other analyzers;

In accordance with the particular case of execution and use, inside the industrial cabinet (with IP 54 protection) for equipment there is a gas analysis module (with IP30 protection), a cooling fan with a grill (with IP54 protection) and switching equipment. The measuring module is hung inside the cabinet with 4 screws; for ease of installation, its design has two handles (on top of the casing) and a slot-recess at the bottom. On the door there is a window for a personal computer with a touch control panel. Electricity and pneumatic supply is supplied to the cabinet from above, cable glands are protected by using industrial sealed regular glands (IP68) in the design.

The gas analyzer 1 functions as follows and implements the following functions:

- continuous selection and pumping of the analyzed medium through the measuring module 3;

- continuous automatic measurement of the content of components simultaneously, such as SO ₂ , NO, NO ₂ , CO, HF, HCl, NH ₃ , N ₂ O, CO ₂ , CH ₄ , CH ₂ O, including H ₂ O and O ₂ , for continuous environmental and technological control.

- visualization of the obtained data using the software "FtirMon";

- transmission upon request of information to external means of data recording (remote computer, server, process control system, etc.) via the Modbus TCP protocol or via 4-20 mA current outputs (option).

After turning on and warming up, the gas analyzer 1 is considered ready for measurements. Measurements of the content of the determined components in the analyzed medium are carried out in a continuous automatic mode.

When using a gas analyzer 1 having a channel for measuring the oxygen content with a sampling probe 10 and a sampling line, a leak test is performed before measurements are taken. Verification is carried out by supplying to the input of the sampling probe 10 or the calibration port, in turn, two gas mixtures: zero gas (nitrogen gas in a cylinder under pressure according to GOST 9293) and GSO-PGS O ₂ /N ₂ with the value of the volume fraction of O ₂ corresponding to the middle of the measurement range. The test results are considered positive if the following conditions are met: if the readings of the gas analyzer 1 in terms of oxygen content do not exceed 0.25% vol. when applying zero gas; if the difference between the readings of the gas analyzer and the certified value of the volume fraction of oxygen GSO-PGS O ₂ /N ₂ does not exceed 5% rel. when applying GSO-PGS O ₂ /N ₂ .

The selection of the analyzed medium is carried out using an ejector pump 2 built into the measuring module 3 and using purge air at a pressure of 4 bar. There are 3 fittings on the suction side to the gas distribution block of the gas analyzer module 1, the 1st is the supply of gas, the 2nd is the sample outlet to an additional analyzer, the 3rd is the selection of the measured gas through the sampling probe. Unused connections (inlets) are hermetically sealed. The gas outlet consists of a high flow mixture of purge air and sample gas. Zero gas is supplied through the "Input 3" connection. The maximum allowable flow rate is 600 dm ³ /h.

The analyzed gas is supplied to the inlet fitting 4, then passes through the gas path through the oxygen sensor 6 and the Fourier spectrometer 7. All elements of the gas path, including analytical cells, are thermostatically controlled and heated to a temperature of 15–20°C above the acid dew point level (usually from +185°C to +220°C). The pressure in the measuring module 3 is also stabilized. Temperature and pressure are controlled by means of pressure sensors 8 and temperature 9. Measuring signals from analytical cells are transmitted to a personal computer with installed software, which is used to process the measurement information and calculate the measured values according to the calibration characteristics. On the side wall of the measuring module 3 there is a power supply connector, a power button, fittings for calibrating with nitrogen and air, and communication interfaces with a personal computer. The main measurement interface of the software menu is displayed on the personal computer monitor, which displays:

- determined components installed for the gas analyzer;

- results of measurements of the content of the determined components;

- measurement ranges;

- units of measurement.

The gas analyzer also has a number of advantages and disadvantages:

- FTIRGAS 22 - the first Russian gas analyzer with a "hot" in-line FTIR analyzer;

- Ability to change the number of measured components and (or) measurement ranges without replacing the device;

- Accurate control of HF after gas cleaning at the enterprises of the aluminum industry; Limit of detection HF: 0.4 mg/m ³ in the range from 0 to 5 mg/m ³ ;

- Measurements of greenhouse gases such as: N ₂ O, CH ₄ and CO ₂ ;

- Service interval is 1 year. Scale calibration is required no more than once every 6 months for most measured components.

Claims (8)

1. A multicomponent gas analyzer, including a housing, a pump, a power supply, a processor, a gas path, pressure and temperature sensors, and a measuring module, characterized in that the measuring module includes fittings for gas inlet and outlet and analytical cells in the form of an oxygen sensor and a Fourier spectrometer, in addition, the multicomponent gas analyzer additionally contains a temperature control unit that provides the possibility of heating the gas path and analytical cells of the measuring module. 2. The gas analyzer according to claim 1, characterized in that it is made with the possibility of supplying the analyzed gas to the inlet fitting and passing it to the Fourier spectrometer through the oxygen sensor, while the measuring module includes three combined inlet fittings forming a heated manifold, and one fitting for gas outlet. 3. The gas analyzer according to claim 2, characterized in that the pump in the form of an ejection type pump is installed in the measuring module, which also contains a heated line for gas discharge and pressure and temperature sensors. 4. The gas analyzer according to claim 3, characterized in that the analytical cells are configured to transmit measurement signals to a personal computer. 5. Gas analyzer according to any one of paragraphs. 1-4, characterized in that it is configured to operate with a sampling probe and a sampling line that provides the possibility of transporting a gas sample from the sampling probe to the inlet of the gas analyzer and maintaining the temperature of the gas sample above the water dew point or acid dew point. 6. The gas analyzer according to claim 5, characterized in that it is made in the form of a module, which makes it possible to install it in a gas analytical cabinet. 7. The gas analyzer according to claim 6, characterized in that the oxygen sensor is made in the form of a cell based on zirconium dioxide, and the Fourier spectrometer contains a Michelson interferometer. 8. The gas analyzer according to claim 2, characterized in that two inlet fittings are made with the possibility of supplying a calibration gas mixture to them.