KR101714731B1 - Compact type NDIR gas analyzer - Google Patents

Abstract

The present invention relates to a compact non-dispersive infrared gas analyzer capable of correcting a deviation of a measurement value caused by a decrease in optical loss and detector sensitivity and analyzing multiple components of gaseous pollutants, An infrared detector disposed at a predetermined distance apart from the infrared detector, a zero gas, an optical filter selectively transmitting only a desired wavelength region, a rotating sector, and a sample gas chamber.

Description

Compact type non-dispersion infrared gas analyzer {Compact type NDIR gas analyzer}

The present invention relates to a non-dispersive infrared gas analyzer, and more particularly, to a compact non-dispersive infrared gas analyzer capable of preventing light loss and a decrease in detector sensitivity.

While the rapid development of modern industrial society has improved the quality of life of human beings, it caused various environmental problems due to indiscreet natural degradation and development. Particularly, due to the rapid increase of energy consumption due to industrial development, the emission of air pollutant gas has increased rapidly, and the pollution problem caused by this is facing serious situation.

In order to prevent this, it is essential to understand the type and concentration of the gas emitted from various pollutants such as factories or automobile exhaust pipes.

Non-dispersive infrared (NDIR) analysis is widely used as a method of measuring the composition and concentration of such gases. The gas analyzer using non-dispersive infrared spectroscopy is a method of measuring the gas concentration by measuring the light absorptance with respect to the concentration using the characteristic that gas molecules absorb light (infrared rays) having a specific wavelength. That is, since specific gas molecules have a characteristic of absorbing only light of a specific wavelength band, it is possible to measure light by irradiating gas molecules with light of various wavelengths and filtering out only the light of the wavelength band absorbed by the gas molecules.

The nondispersive infrared gas analyzer requires only optical filters that transmit only the wavelengths to the photodetector, so that the system is simple and less costly than the dispersion system, and the gas selectivity and measurement reliability are high.

A commonly used non-dispersive infrared gas analyzer includes an infrared source, a rotating sector, an infrared detector, an optical filter, and a sample gas chamber. The light emitted from the infrared source is brought into contact with the gas molecules to be measured in the sample gas chamber, and light of a specific wavelength is absorbed by the gas molecules. The gas concentration can be measured using the principle that the amount of light absorbed increases as the concentration of the gas to be measured increases and the output voltage of the detector decreases.

However, the non-dispersive infrared gas analyzer not only causes optical loss due to deterioration of the infrared source over time, but also causes deviation of the measured value according to the intensity of the initially incident light, The accurate measurement value can not be obtained. Therefore, there is a problem in that it is necessary to carry out calibration from time to time to correct it, or to additionally provide a pretreatment and management facility.

In order to solve such a problem, Korean Unexamined Patent Publication No. 2009-0034668 discloses a comparative cell packed with SPAN gas in addition to a reference cell and a sample cell. In the process of analyzing the sample gas, Using measured values measured using infrared rays passed through the reference cell and infrared rays passing through the comparison cell and infrared rays passing through the comparison cell and the sample cell, Discloses an NDIR gas analyzer capable of simultaneously correcting a zero point deviation and a span deviation.

However, it is possible to correct the deviation of measured values due to optical loss and other external environment. However, since the reference cell and the comparative cell for calibrating the minimum and maximum values of the analysis sensor are provided, the measured values of the component and concentration of the sample There is a problem in that not only the time to obtain is prolonged but also the additional economical cost is incurred as the size of the whole apparatus is increased.

Korean Patent Publication No. 2009-0034668

Disclosure of Invention Technical Problem [8] The present invention has been made in an effort to solve the above-mentioned problems, and it is an object of the present invention to provide a gas analyzer which is simple in comparison with a conventional gas analyzer, And an infrared gas analyzer for analyzing the infrared gas.

In order to achieve the above object, the compact non-dispersive infrared gas analyzer according to the present invention comprises an infrared source 100, an infrared detector 200 spaced apart from the infrared source 100 by a predetermined distance, the infrared source 100, A zero gas 300 located in front of the infrared detector 200 and an optical filter 400 located in front of the zero gas 300 and selectively transmitting only a desired wavelength region of infrared rays irradiated from the infrared source 100 A rotating sector 500 positioned in front of the optical filter 400 and modulating the infrared light having passed through the optical filter 400 into intermittent light and a light source And a sample gas chamber 600 having a space portion capable of receiving a sample gas to be analyzed.

The compact non-dispersive infrared gas analyzer according to the present invention includes an infrared source 100, an infrared detector 200 spaced apart from the infrared source 100 by a predetermined distance, the infrared source 100 and the infrared detector 100 And a zero gas 300 disposed between the infrared source 100 and the zero gas 300 and selectively transmitting only a desired wavelength region of the infrared ray emitted from the infrared source 100. [ A rotating sector 500 positioned in front of the zero gas 300 for modulating the infrared ray having passed through the zero gas 300 into intermittent light and an infrared And a sample gas chamber (600) having a space portion capable of accommodating a sample gas to be analyzed located on the path.

The compact non-dispersive infrared gas analyzer according to the present invention includes an infrared source 100, an infrared detector 200 spaced apart from the infrared source 100 by a predetermined distance, the infrared source 100 and the infrared detector 100 A rotating sector 500 disposed in front of the zero gas 300 for modulating the infrared rays passing through the zero gas 300 into intermittent light; A sample gas chamber 600 having a space portion capable of receiving a sample gas to be analyzed which is located on a traveling path of infrared rays having passed through the sample chamber 600 and a sample gas chamber 600 disposed between the rotating sector 500 and the sample gas chamber 600, And an optical filter (400) selectively transmitting only a desired wavelength region of infrared rays emitted from the infrared source (100).

In the compact non-dispersive infrared gas analysis apparatus according to the present invention, the rotating sector 500 includes a reflector 501 capable of reflecting infrared rays, an absorber 502 capable of absorbing infrared rays, The infrared rays irradiated to the reflector 501 are reflected by the infrared ray detector 200 and the infrared rays irradiated to the hollow portion 503 are reflected by the sample gas chamber 600 And reflected by the infrared ray detector 200 after passing through the infrared ray detector 200.

In the compact non-dispersive infrared gas analysis apparatus according to the present invention, the rotating sector 500 is formed by forming the reflector 501, the absorber 502 and the hollow portion 503 adjacent to each other to form a group And at least two of the same groups as described above are provided.

In the compact non-dispersion infrared gas analysis apparatus according to the present invention, the optical filter 400 is provided with a plurality of unit filters having different wavelength regions to be removed.

In the compact non-dispersive IR gas analyzer according to the present invention, the sample gas chamber 600 includes a gas inlet 601 through which a sample gas to be analyzed flows; A gas outlet 602 through which the introduced sample gas is discharged; A first concave mirror 603 and a second concave mirror 604 for reflecting infrared rays irradiated from the infrared ray source 100 to the infrared ray detector 200; A first transparent window (605) for transmitting infrared rays that have passed through the rotating sector (500) to the sample gas chamber (600); And a second transparent window (606) through which the infrared ray passed through the sample gas chamber (600) is transmitted to the infrared ray detector (200).

The compact non-dispersive IR gas analyzing apparatus according to the present invention has an advantage that the entire apparatus can be small-sized because one zero gas is used.

Further, the gas analyzing apparatus according to the present invention has the effect of shortening the measuring time because the path of the light for correcting the zero point deviation is short.

Further, the gas analyzing apparatus according to the present invention can periodically intercept infrared rays traveling to the infrared detector, thereby extending the service life of the apparatus.

Further, the gas analyzer according to the present invention has an effect that it is possible to easily measure various types of polluted gas.

1 is a top view of a compact non-dispersive IR gas analyzer according to a first embodiment of the present invention.
Fig. 2 is an enlarged view of the dotted line portion in Fig. 1. Fig.
3 is a stereoscopic view of Fig.
4 is a front view of a) rotating sector and b) a front view of an optical filter according to a first embodiment of the present invention.
5 is a front view of a) rotating sector and b) front view of an optical filter according to a second embodiment of the present invention.

Hereinafter, a compact non-dispersion infrared gas analyzer according to the present invention will be described in detail with reference to the accompanying drawings.

Fig. 1 is a plan view of a compact type non-dispersion infrared gas analysis apparatus according to the first embodiment of the present invention, Fig. 2 is an enlarged view of a dotted line portion of Fig. 1, and Fig. 3 is a stereoscopic view of Fig.

1 to 3, the compact non-dispersion infrared gas analyzer according to the first embodiment of the present invention includes an infrared source 100, an infrared detector 200, a zero gas 300, an optical filter 400, A rotating sector 500, and a sample gas chamber 600.

The infrared source 100 is an apparatus for generating infrared rays for measuring the polluted gas in the sample gas chamber 600.

The infrared ray source 100 may be disposed at a predetermined distance from an infrared ray detector 200 to be described later, and may be disposed on the same line as the infrared ray detector 200 on the basis of a virtual horizontal axis in the drawing.

The infrared source 100 may be disposed on a printed circuit board (not shown), and the printed circuit board is not particularly limited as long as it is in the form of other types of mechanical supports and / or electronic connections Do not. In addition, the infrared source 100 is not particularly limited as long as it can emit infrared rays in a region absorbed by a specific sample gas. The infrared source 100 preferably generates infrared rays by passing a current through a resistor of nichrome wire or silicon carbide, but it is not particularly limited as long as it can perform the same function.

The infrared ray detector 200 is disposed at a predetermined distance from the infrared ray source 100 as described above and the infrared rays emitted from the infrared ray source 100 pass through the zero gas 300 and the sample gas chamber 600 Or after returning to the reflector 501 of the rotating sector 500 after passing through the zero gas 300. A detailed description of the movement path and detection principle of the infrared ray will be given later, .

Meanwhile, the zero gas 300 uses a gas that does not absorb infrared rays, and the intensity of infrared rays, which can vary with time or elsewhere, can be corrected, that is, the zero point deviation, .

Here, the zero gas 300 is preferably an inert gas such as nitrogen or argon gas, but it is not particularly limited as long as it is a gas which is not reactive with infrared rays.

Since the optical filter 400 and the rotating sector 500 can reduce the deviation of the measurement value due to the light loss and the sensitivity deterioration of the detector over time, . The construction of the optical filter 400 and the rotating sector 500 will be described in detail with reference to FIG.

The optical filter 400 removes the infrared absorption wavelength region of the remaining interfering component gas except the specific component of the infrared light irradiated from the infrared light source 100 to analyze a specific component contained in the sample gas, And transmits only the infrared absorption wavelength region inherent to the infrared absorption wavelength region.

The optical filter 400 may be provided between the infrared source 100 and the zero gas 300 and / or between the zero gas 300 and the rotating sector 500. In such a configuration, the optical filter 400 may be connected to the rotating sector 500 through a single body.

The optical filter 400 may be provided between the rotating sector 500 and the sample gas chamber 600. In this case, the optical filter 400 may be connected to the rotating sector 500 as a single body, And can be detachably fixed to the sample gas chamber 600 through a detachable attachment / detachment method.

The rotating sector 500 may be positioned in front of or behind the optical filter 400 and may include a reflector 501 capable of reflecting infrared rays, an absorber 502 capable of absorbing infrared rays, (503). The rotating sector 500 performs a function of modulating the infrared ray irradiated from the infrared ray source 100 into intermittent light.

The rotating sector 500 has a conical shape. Specifically, the lower surface of the cone is opened and the reflector 503, the absorber 502, and the hollow portion 503 are alternately arranged on the upper surface.

In order to continuously contact the infrared ray irradiated from the infrared ray source 100 and the reflector 501, the absorber 502 and the hollow portion 503 included in the rotating sector 500, the rotating sector 500 is rotated The motor 700 may be further provided.

The reflector 501 reflects the infrared ray emitted from the infrared ray source 100 to the infrared ray detector 200 via the zero gas 300, Thereby correcting the deviation of the measured value due to the change in intensity of the initial light generated due to the loss of light. In particular, since only one zero gas 300 is provided between the infrared source 100 and the rotating sector 500, the overall size can be reduced as compared with the conventional infrared analyzer, The lowest calibration function can also be performed.

The absorber 502 functions to absorb infrared rays emitted from the infrared source 100. That is, when the infrared ray irradiated from the infrared ray source 100 is in contact with the absorber 502, since the infrared ray is not moved to the infrared ray detector 200, deterioration of the infrared ray detector 200 due to continuous infrared ray contact is prevented So that the life of the detector 200 can be prolonged.

The hollow portion 503 of the rotating sector 500 functions to inflow infrared rays irradiated from the infrared source 100 into the sample gas chamber 600 so that the sample gas can be measured.

The sample gas chamber 600 includes a gas inlet 601, a gas outlet 602, a first concave mirror 603, a second concave mirror 604, a first transparent window 605, a second transparent window 606, And a reflector 607.

The gas inlet 601 is for introducing the sample gas to be analyzed into the chamber 600 and the gas outlet 602 for discharging the gas after the measurement to the outside of the chamber 600. If the inlet 601 and the outlet 602 are provided together, it is possible to continuously measure the gas to be analyzed.

As shown in the drawing, the first concave mirror 603, the second concave mirror 604, and the reflecting mirror 607 contact the infrared ray emitted from the infrared ray source 100 with the sample gas, As shown in FIG.

The first transparent window transmits infrared rays that have passed through the rotating sector 500 to the sample gas chamber 600 and the second transparent window transmits the infrared rays passed through the sample gas chamber 600 to the infrared detector 200 ).

Here, the sample gas chamber 600 is not particularly limited as long as it has a space for allowing gas to flow in and out. However, the inner surface of the sample gas chamber 600 is not corroded or reacted by the sample gas component, It is preferable that the surface is smooth.

5 is a diagram illustrating an optical filter 400 and a rotating sector 500 according to a second embodiment of the present invention.

The optical filter 400 shown in FIG. 4, which is the first embodiment, can selectively remove only one specific wavelength corresponding to a predetermined range, whereas the optical filter 400 in the second embodiment has two or more wavelengths Can be removed.

That is, the optical filter 400 according to the second embodiment of the present invention includes four kinds of filters having different wavelengths that can be removed: a first optical filter 401, a second optical filter 402, a third optical filter 403 ) And the fourth optical filter 404, it is possible to analyze not only a single component but also various kinds of polluted gas.

Although FIG. 5 shows four types of filters, this is only an example, and it is obvious to those skilled in the art that the type of filter can be selected in consideration of the kind of gas to be analyzed.

In order to have the path of the infrared ray reflected by the reflector 501 through the zero gas 300 and reflected by the reflector 501, the rotation sector 500 described in the above- The rotating sector 500 is arranged and designed.

[Formula 1]

L = a x tan (180-2 alpha)

In Equation 1, L represents the length between the infrared source 100 and the infrared detector 200, a represents the length between the infrared source 100 and the rotating sector 500, Represents the angle at which the infrared ray is reflected by the reflector 501 and is incident on the infrared ray detector 200.

The rotation sector 500 can be arranged and designed by determining a value of L and a obtained when? Is previously set in Equation 1 and substituted into?

Hereinafter, the principle of measurement of gaseous pollutants using the compact type non-dispersion infrared gas analyzer of the present invention will be described.

First, the principle of measurement according to the non-dispersion infrared gas analyzer in which the optical filter 400 is provided between the zero gas 300 and the rotating sector 500 will be described in the first embodiment of the present invention.

The sample gas to be measured is introduced into the inlet 601 of the sample gas chamber 600 and the sample gas is discharged to the outlet 602 of the chamber 600. When infrared rays are irradiated from the infrared ray source 100 in the course of the inflow and outflow of the sample gas, the infrared ray is moved to the optical filter 400 and the rotating sector 500 via the zero gas 300 .

At this time, in the optical filter 400, all the wavelengths other than the specific wavelengths related to the measurement of the sample gas are removed, so that only the infrared rays having the wavelengths of the specific region are moved to the rotating sector 500.

On the other hand, when the infrared ray passing through the optical filter 400 hits the reflector 501 of the rotating sector 500, it flows into the infrared detector 200 without flowing into the sample gas chamber 600, Is corrected.

When the infrared ray passing through the optical filter 400 passes straight through the hollow portion 502 of the rotating sector 500, the infrared ray passes through the first transparent window 605 and enters the sample gas chamber 600 ≪ / RTI > Part of the infrared ray introduced into the sample gas chamber 600 is absorbed by the sample gas so that the infrared rays having lower intensity than the initial infrared ray reach the ultraviolet ray detector 200 after passing through the second transparent window 606.

On the other hand, when the infrared ray passing through the optical filter 400 is struck on the absorber 502 of the rotating sector 500, not only the infrared ray is not introduced into the sample gas chamber 600 but also the infrared ray detector 200 The deterioration of the infrared ray detector 200 can be prevented.

The following is a description of a measurement principle according to a non-dispersion infrared gas analyzer in which an optical filter 400 is provided between an infrared source 100 and a zero gas 300. FIG.

The sample gas to be measured is introduced into the inlet 601 of the sample gas chamber 600 and the sample gas is discharged to the outlet 602 of the chamber 600. In this process, when infrared rays are irradiated, the generated infrared rays are moved to the optical filter 400. In the optical filter 400, all the wavelengths other than the specific wavelengths related to the measurement of the sample gas are removed, Only the infrared ray moves to the zero gas 300.

Hereinafter, the flow of the infrared rays is the same as that of the non-dispersion infrared gas analysis apparatus having the optical filter 400 between the zero gas 300 and the rotating sector 500,

Next, the principle of measurement according to the non-dispersion infrared gas analyzer having the optical filter 400 between the rotating sector 500 and the chamber 600 will be described.

The sample gas to be measured is introduced into the inlet 601 of the sample gas chamber 600 and the sample gas is discharged to the outlet 602 of the chamber 600. In this process, when the infrared ray is irradiated, the infrared ray passes through the zero gas 300 and then moves to the rotating sector 500.

When the infrared ray hits the reflector 501 of the rotating sector 500, the infrared ray is introduced into the infrared detector 200 without entering the sample gas chamber 600, and the zero point deviation is corrected at this time.

When the infrared ray passes straight through the hollow portion 502 of the rotating sector 500, the infrared ray reaches the optical filter 400 positioned between the rotating sector 500 and the chamber 100. At this time, the optical filter 400 Only infrared rays having a wavelength of a specific region pass through the first transparent window 605 and move to the chamber 100 because the infrared rays except for a specific wavelength related to the measurement of the sample gas are all removed.

Hereinafter, the flow of the infrared rays is the same as that of the non-dispersion infrared gas analysis apparatus having the optical filter 400 between the zero gas 300 and the rotating sector 500,

Hereinafter, the principle of measuring various kinds of polluted gas according to the second embodiment of the present invention will be described.

When the optical filter 400 is provided between the zero gas 300 and the rotating sector 500, the optical filter 400 includes a first optical filter 401, a second optical filter 402, The third optical filter 403, and the fourth optical filter 404, the different components can be simultaneously analyzed.

That is, the zero point deviation is corrected by the same principle as described in the first embodiment, and the infrared ray having passed through the zero gas 300 passes through the first optical filter 401 and the hollow portion 503 of the rotating sector 500 Pass sequentially. Thereafter, after reacting with the sample gas in the chamber 100, the infrared light is introduced into the infrared detector 200 again and analyzed for the amount of infrared light for a specific component corresponding to the first optical filter 401.

When the optical filter 400 and the rotating sector 500 are rotated, a specific wavelength different from that of the first optical filter 401 is removed from the second optical filter 402 and then moved to the infrared detector 200 .

By rotating the optical filter 400 sequentially divided into a plurality of sections in this manner, it becomes possible to measure the concentration of the multiple gases having different components contained in the sample gas.

It will be apparent to those skilled in the art that various modifications and variations can be made in the present invention without departing from the spirit and scope of the invention will be.

100: Infrared source 200: Infrared detector
300: zero gas 400: optical filter
401: first optical filter 402: second optical filter
403: third optical filter 404: fourth optical filter
500: rotating sector
501: reflector 502: absorber
503: hollow part
600: sample gas chamber
601: Gas inlet 602: Gas outlet
603: first concave mirror 604: second concave mirror
605: first transparent window 606: second transparent window
607: reflector
700: motor

Claims (7)

An infrared source 100;
An infrared ray detector 200 spaced apart from the infrared ray source 100 by a predetermined distance;
A zero gas (300) located in front of the infrared source (100) and the infrared detector (200);
An optical filter (400) located in front of the zero gas (300) and selectively transmitting only a desired wavelength region of infrared rays irradiated from the infrared source (100);
A rotating sector 500 located in front of the optical filter 400 and modulating the infrared ray passing through the optical filter 400 into intermittent light; And
And a sample gas chamber (600) having a space portion capable of receiving a sample gas to be analyzed which is located on a traveling path of infrared rays that has passed through the rotating sector (500)
The rotating sector 500 has a conical shape including a reflector 501 capable of reflecting infrared rays, an absorber 502 capable of absorbing infrared rays, and a hollow portion 503 through which infrared rays pass, Is reflected by the infrared detector 200 and the infrared light irradiated to the hollow portion 503 is reflected by the infrared detector 200 after passing through the sample gas chamber 600 A compact non-dispersive infrared gas analyzer.
An infrared source 100;
An infrared ray detector 200 spaced apart from the infrared ray source 100 by a predetermined distance;
A zero gas (300) located in front of the infrared source (100) and the infrared detector (200);
An optical filter 400 positioned between the infrared source 100 and the zero gas 300 and selectively transmitting only a desired wavelength region of the infrared light irradiated from the infrared source 100;
A rotating sector 500 located in front of the zero gas 300 and modulating the infrared ray having passed through the zero gas 300 into intermittent light; And
And a sample gas chamber (600) having a space portion capable of receiving a sample gas to be analyzed which is located on a traveling path of infrared rays that has passed through the rotating sector (500)
The rotating sector 500 has a conical shape including a reflector 501 capable of reflecting infrared rays, an absorber 502 capable of absorbing infrared rays, and a hollow portion 503 through which infrared rays pass, Is reflected by the infrared detector 200 and the infrared light irradiated to the hollow portion 503 is reflected by the infrared detector 200 after passing through the sample gas chamber 600 A compact non-dispersive infrared gas analyzer.
An infrared source 100;
An infrared ray detector 200 spaced apart from the infrared ray source 100 by a predetermined distance;
A zero gas (300) located in front of the infrared source (100) and the infrared detector (200);
A rotating sector 500 located in front of the zero gas 300 and modulating the infrared ray having passed through the zero gas 300 into intermittent light;
A sample gas chamber 600 having a space portion capable of receiving a sample gas to be analyzed which is located on a traveling path of infrared rays that has passed through the rotating sector 500; And an optical filter (400) disposed between the rotating sector (500) and the sample gas chamber (600) and selectively transmitting only a desired wavelength region of infrared rays irradiated from the infrared source (100)
The rotating sector 500 has a conical shape including a reflector 501 capable of reflecting infrared rays, an absorber 502 capable of absorbing infrared rays, and a hollow portion 503 through which infrared rays pass, Is reflected by the infrared detector 200 and the infrared light irradiated to the hollow portion 503 is reflected by the infrared detector 200 after passing through the sample gas chamber 600 A compact non-dispersive infrared gas analyzer.
delete 4. The method according to any one of claims 1 to 3,
The reflector 501, the absorber 502, and the hollow portion 503 are disposed adjacent to each other to form a group, and at least two of the same groups as described above are provided in the rotating sector 500 A compact, non-dispersive infrared gas analyzer featuring features.
4. The method according to any one of claims 1 to 3,
Wherein the optical filter (400) comprises a plurality of unit filters having different wavelength regions to be removed.
4. The method according to any one of claims 1 to 3,
The sample gas chamber 600 includes a gas inlet 601 through which a sample gas to be analyzed flows; A gas outlet 602 through which the introduced sample gas is discharged; A first concave mirror 603 and a second concave mirror 604 for reflecting infrared rays irradiated from the infrared ray source 100 to the infrared ray detector 200; A first transparent window (605) for transmitting infrared rays that have passed through the rotating sector (500) to the sample gas chamber (600); And a second transparent window (606) through which the infrared ray passed through the sample gas chamber (600) is transmitted to the infrared detector (200).

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