JPS58166253A - Device for measuring concentration of component - Google Patents

Abstract

PURPOSE:To enable simultaneous measurement of dry base oxygen concn., wet base oxygen concn., and moisture concn., by introducing the not dehumidified gas to be measured into the first partition tube and the dehumidified gas to be measured into the second partition tube. CONSTITUTION:A measuring device has test tube type zirconia tubes 11, 12 forming the first and the second partition walls, and electrodes 13-16. The tubes 11, 12 are arranged in a pipe 2, with their tops opposite to each other. They are maintained at the same constant temp. in a thermostat comprising a heater, etc. The dehumidified and not dehumidified gases to be measured are introduced into the first and second partition wall tubes 11, 12, respectively, and measurements of dry base and wet base oxygen concns. and moisture concn. are executed by such a constitution.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention is directed to
This invention relates to a component concentration measuring device that measures oxygen concentration and water concentration in a measurement gas using zirconia porcelain stabilized with > or the like.

Conventionally, an oxygen concentration rILit as shown in FIG. 1 has been known. In this figure, 1 is a zirconia pipe, 2
One night, 3 was fixed to a metal pipe, and 3 was fixed to pipe 2.
4 is a heat insulating material, 5 and 6 are electrodes bonded to both sides of the zirconia pipe 1, 7 is a signal processing section, and 8 is a receiver. The pipe 2, the heater 3, the heat insulating material 4, and the temperature sensor and adjustment section (not shown) constitute a constant temperature bath, whereby the zirconia pipe 1 is kept at a constant temperature (approximately 700'C). In the concentration meter, the measurement gas Gx is introduced into the interior A (measurement gas introduction part) of the zirconia pipe 1, and the air flIB formed by the zirconia pipe 1 and the pipe 2 is
(Reference gas introduction part) with reference gas Ga (usually air)
is introduced, an electromotive force E known by the Nernst equation ((1) 2′ described later) is generated between electrodes 5 and 6 based on the difference in oxygen concentration between the two gases, and this The corresponding signal is sent to the signal processing unit 7. The signal processing unit 7 performs a predetermined calculation and displays the oxygen degree [v01%1] in the receiver 8 as a building block.
Let it be recorded.

E= (RT/nF)In(Px/Pa)-(1
) However, R...Gas constant T...Absolute temperature n...
4 F...Faraday constant P×...Oxygen concentration in the measurement gas [v01%I Pa...Oxygen concentration in the reference gas [vo1%] By the way, in the field of industrial analysis, for example, smoke leakage, etc. When measuring exhaust gas components, simultaneous measurement of dry base oxygen concentration, wet base oxygen concentration, and water concentration is strongly desired.

However, as mentioned above, with conventional zirconia oxygen meters,
Since only the oxygen concentration of the measurement gas can be measured,
In order to meet the above requirements, it became necessary to use other analyzers at the same time, which caused the problem of being extremely complicated.

The present invention has been made in view of this problem, and its purpose is to realize a component concentration measuring device that can simultaneously measure dry base oxygen concentration, wet base oxygen concentration, and water concentration.

Hereinafter, the present invention will be described in detail with reference to the drawings.

FIG. 2 is an explanatory diagram showing an embodiment of the present invention (the same parts as in FIG. 1 are given the same reference numerals).

In this FIG. 2, 11 and 12 are test tube-shaped zirconia forming the first and second partition walls, respectively;
Reference numeral 6 denotes an electrode, and test tube-shaped zirconia 11 and 12 are arranged in the pipe 2 with their tips (fixed parts of the electrodes) facing each other. 17 is a filter 18 at the measurement gas sampling point
A pipe line 19 communicates the inside A1 of the zirconia 11 and the inside (measurement gas introduction part) A2 of the zirconia 12 via a dehumidifier 20, 21 2 is a conduit that communicates the inside A2 of the zirconia 12 with the exhaust destination, and 22 is an ejector installed in the conduit 21. Note that the openings of the zirconias 11 and 12 are closed with lids 23 and 24. Furthermore, air is introduced into the nine circles (reference gas introduction part) B formed by the pipe 2 and the zirconia 11 and 12 by forced or natural flow.

25 and 26 are amplifiers, and 27 is an arithmetic unit.

The amplifier 25 outputs a signal E1 obtained by amplifying the electromotive horn between the electrodes 13 and 14 to the performance section 27.
The signal E2 which amplifies the electromotive force of 5 and 16 darkness is output to the calculation section 27, and the calculation section 27 outputs the signal E1 and El
Based on this, a predetermined calculation, which will be described later, is performed, and a wet base oxygen concentration signal E3, a dry base oxygen concentration signal E4, and a water concentration signal E5 are output to a receiver (not shown).

Next, the operation of the component concentration measuring device having the above configuration will be explained.

Zirconia 11 and 12 are kept at a constant (and same) a! It is maintained at a certain degree. In this state, when the injector 22 is driven, the measured gas is collected at the sampling point - ÷ filter 18 -> pipe line 17 -> Jill.
Inside A1 of near 11 → pipe 19 → dehumidifier 2o → pipe 19
-→Inside A2 of zirconia 12→Niji lctor 22→Exhaust destination. For this reason, the internal A of Gilnia 11
A raw measurement gas that is not dehumidified is introduced into the zirconia 12, and a measurement gas that has been dehumidified by a dehumidifier 20 is introduced into the interior A2 of the zirconia 12. On the other hand, air is introduced outside the zirconias 11 and 12, that is, into the inside 1i1B.

Therefore, the signal El corresponding to the electromotive force between electrodes 13 and 14
And the signal E2 corresponding to the electromotive force between the electrodes 15 and 16 is
Equations (2) and (3) are obtained.

El = Kln(Px s'/21 >-(2) El
= Klri (PX 2/21)” (3) However, K=R
T/n F...Constant PXt...Oxygen concentration in non-dehumidified gas [v01
%] PX2...Oxygen concentration in the dehumidified measurement gas [v01%
] By the way, if the amount of oxygen and the amount of water contained in the volume V of the measurement gas that is not dehumidified are VO and VW, then each of the above oxygen concentrations Px and Px2 and the water concentration H [vo
1%] is expressed by equations (4) to (6).

px 1 = vo/V-(4) px 2 = VO/V-vvt-(5) H= v
w/V... (6) Also, equation (7) can be obtained from equations (4) to (6).

H=1−(Px 1/Px 2 )−(7) Therefore, the calculation unit 27 calculates the signal E based on equations (2) and (3).
r, E2 are linearized to form a signal E3. which is proportional to Pxl, PX2. In addition to outputting E4, this linearized signal E
3. Using E4, calculate H from equation (7) and output f8 No. E5 proportional to this. Therefore, the signal E3 becomes the wet base oxygen concentration signal, the signal E4 becomes the dry base oxygen concentration signal, and the 4is signal E5 becomes the water concentration signal.

Note that instead of the introduction path for the measurement gas in the above embodiment,
For example, an introduction path that leads a non-dehumidified measurement gas to the interior A+ of zirconia '11, a reference gas to the interior Az of zirconia 12, and a dehumidified measurement gas to the air 111B formed by the zirconia 11.12 and the pipe 2, respectively. may be configured. Alternatively, the introduction path for the non-dehumidified measurement gas and the introduction path for the dehumidified measurement gas may be arranged in parallel.

Furthermore, the constant temperature bath need not be one as in the above embodiment, but may be provided for each zirconia. Further, the calculation formula for determining the moisture content 1iH does not need to be limited to the formula (7), and calculations based on the following formula may be performed.

2-Et =K (lnPx z -In21-1nPx 1+l
n21 )=K (1npx 2-1nPx I)-
Kin(Px 2 /PX t ),', H"1-e (Et Ez /K) As explained above, the component concentration measuring device according to the present invention introduces a non-dehumidified measurement gas to the i-th partition wall, and According to the present invention, a dry base oxygen concentration signal, a wet base oxygen concentration signal, and a water concentration signal can be obtained at the same time.

[Brief explanation of the drawing]

FIG. 1 is an explanatory diagram of a conventional zirconia oxygen meter, and FIG. 2 is an explanatory diagram showing an embodiment of a component concentration measuring device according to the present invention. 2... Metal pipe 3... Heater 4... Insulating material 11... Zirconia (first partition) 12... Zirconia (second partition) 13.14.15.16... Electrode 17.19.21...Pipe line

Claims (1)

[Claims] In a component concentration measuring device that utilizes the fact that electromotive force occurs in a zirconia porcelain partition wall based on the difference in oxygen concentration of gas on both sides of the partition wall, first and second partition walls are provided as the partition wall, A measuring gas that is not dehumidified is guided to one side of the partition wall, and a dehumidified measurement gas is guided to one side of the second partition wall, and from the electromotive force at the first and second partition walls,
Component concentration measuring device W0 designed to obtain a dry base oxygen concentration signal, a wet base oxygen concentration signal, and a moisture signal.