JPH0635165Y2 - Chemiluminescent gas analyzer for measuring multiple samples - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial field of application] The present invention is a chemistry used for measuring the concentration of a specific component gas (for example, NO gas) contained in the atmosphere or exhaust gas. Luminous gas analyzer (Chemical Luminesce
nce Detector: generally called CLD), particularly to a chemiluminescence-type gas analyzer for measuring a plurality of samples, which is capable of simultaneously measuring a plurality of sample gases with one unit.

[Conventional technology]

A typical chemiluminescent gas analyzer for measuring multiple samples of this type is currently, for example, NO _x (NO,
Like a so-called NO / NO ₂ gas analyzer for measuring the concentration of NO ₂ ), one sample gas (atmosphere) is divided into multiple (in this case, two) sample gases, and one of the sample gases For the sample gas, the NO concentration originally contained therein was measured, and for the other sample gas, the total NO concentration was measured by converting the NO ₂ gas contained therein into the NO gas prior to the measurement. , By the difference method
Most well-known are those that are configured to determine NO ₂ concentration, that is, those that are originally used to measure multiple specific components in one sample gas, that is, the multiple component measurement type. Other than this, for example, one configured to individually measure the total NO concentration contained in each of a plurality of different sample gases such as a plurality of exhaust gases from a plurality of automobiles, that is, a plurality of originally different plurality A multiple sample measurement type, which is used to measure one specific component in each sample gas, is also conceivable.

However, in each case, the usage is different and the measurement principle itself is the same. Therefore, here, the former technique of the multiple component measurement type will be examined.

That is, FIG. 8 shows the overall schematic configuration of a NO / NO ₂ gas analyzer as an example of a chemiluminescence gas analyzer for measuring multiple samples, which is well known in the past. For example, the sample gas S0 such as the atmosphere is first divided into the two sample gases S1 and S2, and no special chemical treatment is applied to the first sample gas S1 but the other second sample gas S2. Is subjected to a chemical pretreatment in which the NO ₂ / NO converter c converts the NO ₂ gas contained therein into NO gas.

Further, d1 is a first chemiluminescence reaction detector for detecting the NO concentration, and the detector d1 has the first sample gas S1 and a reference gas (generally zero gas such as fresh air) Z Is a first fluid modulation means such as a three-way solenoid valve
The ozone gas O as a reaction gas generated by the first ozone generator x1 is constantly supplied while being alternately switched and supplied by v1, and thus the first chemiluminescence reaction detector d1 is used to supply the first sample. The concentration of NO gas originally contained in the gas S1 (that is, the sample gas S0) is detected.

On the other hand, d2 is also a second chemiluminescence reaction detector for detecting NO concentration, and this detector d2 contains the second sample gas S2 and the reference gas (zero gas) Z, for example, a three-way electromagnetic wave. The ozone gas O generated by the second ozone generator x2 is constantly supplied while being alternately switched and supplied by the second fluid modulating means v2 such as a valve, and thus, by the second chemiluminescence reaction detector d2, The total NO concentration of NO gas and NO ₂ gas contained in the second sample gas S2 (that is, sample gas S0) is detected.

The concentration of NO ₂ gas originally contained in the sample gas S0 is the total NO detection value of the second detector d2 and the first NO 2 concentration.
It is calculated from the difference from the NO detected value by the detector d1.

The gas containing the residual ozone gas that has passed through the first and second detectors d1 and d2 is discharged to the outside via the first and second ozone decomposers y1 and y2, respectively.

[Problems to be solved by the device]

The conventional chemiluminescent gas analyzer (NO / NO ₂ value gas analyzer) configured as described above for measuring multiple samples alternately detects the sample gas S1 (S2) and the reference gas (zero gas) Z. Since the fluid modulation method of supplying to the device d1 (d2) (for details, see Japanese Patent Publication No. 56-48822, for example) is adopted, the effect of dark current is removed, and
Although it has the great advantage of being able to effectively eliminate zero drift and performing stable analysis at all times, (a) it requires multiple detectors d1 and d2 as many as the sample gases S1 and S2, Consequently, the fluid modulation means v
Also for 1, v2, ozone generator x1, x2, ozone decomposer y1, y2, a plurality of each is required, therefore, the overall structure becomes large and complicated, and the manufacturing cost is high, and further, It is necessary to carefully adjust between the two detector systems. (A) When multiple detectors d1 and d2 are supplied, sample gas S1 (S2) and ozone gas O are unnecessary reference gases (zero gas). Since the ozone gas O is constantly supplied regardless of the Z supply, the ozone gas O is wasted a lot and the life of the ozone decomposers y1 and y2 is shortened.

The present invention has been made in view of the above circumstances, and an object thereof is to provide a detection system having only one chemiluminescent reaction detector, but to simultaneously measure a plurality of sample gases. By doing so, it is an object of the present invention to develop and provide a chemiluminescent gas analyzer for measuring a plurality of samples, which can solve the above-mentioned various conventional problems all at once.

[Means for Solving the Problems]

In order to achieve the above-mentioned object, the chemiluminescence gas analyzer for measuring multiple samples according to the present invention, as shown in the claim correspondence diagram of FIG. m)
Of the sample gas S1 to Sm are sequentially switched and supplied at a constant fundamental fluid modulation frequency (M hertz), and the ozone gas O and the reference gas Z are supplied to the chemiluminescence reaction detector D as described above. A plurality of sample gases S1 are supplied by alternately switching and supplying at another fluid modulation frequency (N hertz) different from the basic fluid modulation frequency (M hertz).
The feature is that Sm is analyzed simultaneously and continuously.

[Action]

The action exerted by such a characteristic configuration is as follows.

That is, according to the chemiluminescence gas analyzer for measuring multiple samples according to the present invention, the timing chart of FIG. 2 (in this example, the number m of sample gases is 3, the fundamental fluid modulation frequency M is 1 hertz, As is clear from another fluid modulation frequency N of 3 Hertz), the sample gas S1, S2, S3 is supplied to one chemiluminescent reaction detector D in this order, and compared with the ozone gas O during one cycle. The gas (generally zero gas) Z is switched and supplied to the same detector D in three cycles, so that in the detector D, NO concentration detection of the sample gas S1 (with ozone gas) → zero detection (without ozone gas) → sample gas S2 NO concentration detection (with ozone gas)
→ Zero detection (without ozone gas) → NO concentration detection of sample gas S3 (with ozone gas) → Zero detection (without ozone gas) ...

As described above, according to the chemiluminescence gas analyzer for measuring a plurality of samples according to the present invention, although a detection system having only one chemiluminescence reaction detector D is provided,
Sufficient measurement can be performed for each of the multiple sample gases S1, S2, ... Sm.
The entire structure can be made extremely simple and compact, and the manufacturing cost can be significantly reduced.

Further, since the ozone gas O is not supplied when the comparison gas (zero gas) Z that does not require the ozone gas O is supplied,
There is almost no waste of the ozone gas O, the life of the ozone decomposer can be extended, and the durability of the apparatus can be improved.

Further, in the chemiluminescence gas analyzer for measuring a plurality of samples according to the present invention, the sample gas S1 (S2, ..., Sm) and the reference gas (zero gas) Z are directly connected to each other as in the conventional configuration. Does not perform fluid modulation, but as a result, similar fluid modulation is performed, so that the effects of dark current, etc. are eliminated and zero drift can be effectively eliminated, and stable analysis is always performed. It also retains the same advantages as the conventional ones.

〔Example〕

Hereinafter, a specific embodiment of a chemiluminescent gas analyzer for measuring a plurality of samples according to the present invention will be described with reference to FIGS. 3 to 7.
It will be explained based on.

FIG. 3 shows an overall schematic configuration of a NO / NO ₂ gas analyzer constructed by applying the present invention. For example, a sample gas S0 such as the atmosphere is first divided into two sample gases S1 and S2. , The first sample gas S1, the first filter 1, the first pump 2, the first needle valve 3, the electronic cooler E
Through the main fluid modulation means VA consisting of, for example, a four-way rotary valve in a state where no special chemical treatment is applied, and the other second sample gas S2 is converted into NO ₂ / NO. After the chemical pretreatment of converting the NO ₂ gas contained therein into the NO gas by the vessel C, the second filter 4, the second pump 5, the second needle valve 6, the electron Through the cooler E, the main fluid modulation means VA
It is configured to be introduced to.

D is a chemiluminescent reaction detector for detecting NO concentration, and the detector D is connected to the main fluid modulating means.
By the VA, the first sample gas S1 and the second sample gas S2 are sequentially switched and supplied at a predetermined basic fluid modulation frequency (1 Hz in this example) via the capillary K, and also by the ozone generator X. The generated ozone gas O as a reaction gas and the comparative gas (generally zero gas: fresh air in this example) are compared with the basic fluid modulation frequency (1 Hz) by the auxiliary fluid modulation means VB composed of, for example, a three-way rotary valve. Different different fluid modulation frequency (2 in this example)
Hz), and is configured to be sequentially switched and supplied.

Note that the general relationship between the fluid modulation frequencies of the two fluid modulation means VA, VB is that the fluid modulation frequency by the main fluid modulation means VA is M, the number of sample gases S1, S2, ..., Sm is m, and an integer is Assuming that l (= 1, 2, ...), the fluid modulation frequency N by the sub-fluid modulation means VB may be N≈l · m · M ... Or N≈M / (l · m).

The gas containing the residual ozone gas that has passed through the chemiluminescence reaction detector D is discharged to the outside through the ozone decomposer Y.

In the NO / NO ₂ gas analyzer configured as described above,
As is clear from the timing chart of FIG. 4, one cycle (for example, M = 1 Hz) in which m (= 2) sample gases S1 and S2 are supplied in this order to one chemiluminescent reaction detector D
Ozone gas O and comparison gas (zero gas) Z are 2
Since it is switched and supplied to the same detector D at a cycle (N = 2 Hz: this is the case where l = 1 and according to the above equation), the NO concentration of the sample gas S1 is detected at that detector D (with ozone gas) → Zero detection (without ozone gas) → NO concentration detection of sample gas S2 (with ozone gas) → zero detection (without ozone gas)), and so on are sequentially performed, so that the first sample gas S1 (that is, sample gas)
The concentration of NO gas originally contained in S0) and contained in the second sample gas S2 (that is, sample gas S0)
The total NO concentration of NO gas and NO ₂ gas is sequentially measured by the single chemiluminescence reaction detector D without influence of dark current and zero drift.

In the above embodiment in which the basic fluid modulation frequency M is 1 Hz, the fluid modulation frequency N of the ozone gas O and the comparative gas Z is not limited to 2 Hz, but ... 1/6 Hz, 1/4 Hz, 1/2 H
z, 4 Hz, 6 Hz, ... Or, as shown in another embodiment shown in FIGS. 5 and 6, the basic fluid modulation frequency M is set to 2 Hz and another fluid modulation frequency N is set to 1
It will be apparent from the above general description (and equations) that various modifications are possible, such as Hz.

In the case of the other embodiment, as is clear from the timing chart of FIG. 6, in the detector D, the NO concentration of the sample gas S1 is detected (with ozone gas) → the sample gas S2.
NO concentration detection (with ozone gas) → zero detection (without ozone gas: common to sample gases S1 and S2) ...

By the way, in each of the above examples, the sample gas S1, S2
Although the case where the number m is 2 is shown, when the number m is 3 or more, the main fluid modulating means is
For example, as shown in FIG. 7 (a), the open / close solenoid valves B1, B2,
, Bm and capillaries K1, K2, ..., Km may be used, or in order to avoid disadvantages such as switching speed, durability, cost, etc. possessed by such solenoid valve type. , For example, a plurality of sample gases S1, S2, ..., Sm introducing flow paths L1, L2, as shown in FIG.
, Lm are provided on the periphery, and a lead-out passage L0 to the detector D is provided at the center of the bottom, and the introduction passages L1, L2, ..., Lm are sequentially selected with respect to the lead-out passage L0. A multi-way rotary valve configured by providing a crescent-shaped rotor R that communicates with the above may be used.

[Effect of device]

As is clear from the above detailed description, a chemiluminescent gas analyzer for measuring multiple samples according to the present invention is used for one chemiluminescent reaction detector, and a plurality of sample gases are supplied at a constant fundamental fluid modulation frequency. A plurality of ozone gas and reference gas are alternately switched and supplied to the chemiluminescent reaction detector at a different fluid modulation frequency different from the basic fluid modulation frequency. Since the sample gas of each sample gas is analyzed simultaneously and continuously, it is possible to obtain the modulation signals of multiple sample gases at the same time, and thus it is possible to obtain the concentration signals of multiple sample gases. By installing a detection system that has only a luminescence reaction detector, multiple sample gases can be used in the same condition without the influence of dark current and zero drift. And it can be analyzed continuously.

Further, according to the present invention, the entire device can be configured with a very simple and compact overall structure as compared with the conventional device, and the manufacturing cost can be significantly reduced and the device durability can be improved.

[Brief description of drawings]

FIG. 1 shows a basic conceptual diagram (claim correspondence diagram) of a chemiluminescence gas analyzer for measuring multiple samples according to the present invention,
FIG. 2 shows a timing chart for explaining the operation. 3 to 7 show specific embodiments of the present invention, FIG. 3 is an overall configuration diagram of a NO / NO ₂ gas analyzer configured by applying the present invention, and FIG. FIG. 5 is a timing chart of a main part, FIG. 5 is an overall configuration diagram of a NO / NO ₂ gas analyzer according to another embodiment, and FIG. 6 is a timing chart of the main part thereof. (B) is a schematic configuration diagram of a main part in another embodiment. And, FIG. 8 is for explaining the technical background of the present invention and the problems of the prior art, that is, NO as a conventional general chemiluminescence gas analyzer for measuring multiple samples.
Fig. ₂ shows an overall schematic configuration diagram of a / NO ₂ gas analyzer. D: Chemiluminescent reaction detector D, S, S2, ..., Sm: Multiple sample gases M Hertz: Basic fluid modulation frequency, O: Ozone gas, Z: Reference gas, m: Number of sample gases, l: Integer, N Hertz: Another fluid modulation frequency.

Continuation of the front page (56) Bibliographic references Sho 63-31359 (JP, U) JP 58-25981 (JP, B2) JP 56-48822 (JP, B2)

Claims (1)

[Scope of utility model registration request] 1. A plurality of sample gases are sequentially switched and supplied to one chemiluminescent reaction detector at a constant basic fluid modulation frequency, and ozone gas is supplied to the chemiluminescent reaction detector. And a reference gas are alternately switched and supplied at another fluid modulation frequency different from the basic fluid modulation frequency to simultaneously and continuously analyze a plurality of sample gases. Chemiluminescent gas analyzer for measurement.