WO1987006703A1 - Procede permettant de definir le rapport de melange dans des melanges de gaz binaires - Google Patents

Procede permettant de definir le rapport de melange dans des melanges de gaz binaires Download PDF

Info

Publication number
WO1987006703A1
WO1987006703A1 PCT/FI1987/000058 FI8700058W WO8706703A1 WO 1987006703 A1 WO1987006703 A1 WO 1987006703A1 FI 8700058 W FI8700058 W FI 8700058W WO 8706703 A1 WO8706703 A1 WO 8706703A1
Authority
WO
WIPO (PCT)
Prior art keywords
gas
sound
mixture
calculated
under measurement
Prior art date
Application number
PCT/FI1987/000058
Other languages
English (en)
Inventor
Pekka HIISMÄKI
Esko Kantonen
Veikko Kämäräinen
Markus Leino
Original Assignee
Valtion Teknillinen Tutkimuskeskus
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Valtion Teknillinen Tutkimuskeskus filed Critical Valtion Teknillinen Tutkimuskeskus
Publication of WO1987006703A1 publication Critical patent/WO1987006703A1/fr

Links

Classifications

    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
    • G01N29/00—Investigating or analysing materials by the use of ultrasonic, sonic or infrasonic waves; Visualisation of the interior of objects by transmitting ultrasonic or sonic waves through the object
    • G01N29/02—Analysing fluids
    • G01N29/024—Analysing fluids by measuring propagation velocity or propagation time of acoustic waves
    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
    • G01N29/00—Investigating or analysing materials by the use of ultrasonic, sonic or infrasonic waves; Visualisation of the interior of objects by transmitting ultrasonic or sonic waves through the object
    • G01N29/22—Details, e.g. general constructional or apparatus details
    • G01N29/32—Arrangements for suppressing undesired influences, e.g. temperature or pressure variations, compensating for signal noise
    • G01N29/326—Arrangements for suppressing undesired influences, e.g. temperature or pressure variations, compensating for signal noise compensating for temperature variations
    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
    • G01N2291/00—Indexing codes associated with group G01N29/00
    • G01N2291/02—Indexing codes associated with the analysed material
    • G01N2291/021—Gases
    • G01N2291/0212—Binary gases

Definitions

  • the present invention relates to a method for defining the mixture ratio in binary gas mixtures, based on measuring the speed of sound and the temperature.
  • binary mixture here includes such multicomponent mixtures which can be divided into two parts so that the composition of each part remains unchanged and only their reciprocal mixture ratio varies.
  • a hygrometer based on measuring the speed of sound is described in the Finnish patent 54977, "Apparatus for measuring humidity in the exhaust steam of a drying process".
  • the measurement with the apparatus of the specification is carried out so that the measuring sensor contains one sound transmitter and two detectors.
  • the suggested technical embodiment comprises accurate phasewise measurement of sound transmitted, at a constant frequency.
  • a drawback of the said method is that it is difficult to achieve sufficient accuracy in conditions of high industrial noise.
  • Another hygrometer based on the speed of sound is the one sold by the company Mahlo GMBH, wherein a pressure-operated injector is employed for sucking a sample flow of the atmosphere under measurement into a fluidistor oscillator, the pitch whereof is defined according to the speed of sound in the sample gas , but also accord ing to the d imens ions of the resonator which is sensitive to dirt.
  • Sonic measuring of humidity has recently been discussed in the article by Morris & Dagle, "A Fast Response Sonic Hygrometer", Moisture and Humidity 1985, Proceedings of the 1985 International Symposium on Moisture and Humidity, Washington DC, April 15-18, 1985.
  • the object of the method of the present invention is to eliminate the drawbacks of the prior art arrangements.
  • the invention is characterized in that a wideband sound signal is made to proceed in an acoustic tube filled with the gas under measurement, via two paths of differing lengths, from one transmitter to one receiver; and in that the longer path is formed of one or several parallel branches connected to the same junction of the main tube, so that the sound from the end of each side branch is reflected back into the main branch; and in that the transit time difference t corresponding to the length difference L of the separate paths is determined as the distance of the side peaks of the correlation function of the received signal from the origin; and in that the average molecular weight M of the gas mixture under measurement is calculated from the formula
  • the accurate measurement of the sound speed is based first of all on the use of an acoustic tube, the purpose whereof is to form an exactly defined measuring geometry and to insulate the measuring space from environmental noise.
  • the employed transmitted sound signal is a wideband signal, which allows the transit time to be determined on the basis of the autocorrelation function of the received signal, or on the basis of an appropriately formed crosscorrelation function.
  • the use of the acoustic tube offers a remarkable advantage also in that the sound transmitter and receiver can be placed outside the atmosphere under measurement - which often brings about difficulties - separated by a sound-penetrating film if necessary.
  • the acoustic tube With the acoustic tube, it is likewise natural to arrange two paths with differing lengths from the sound transmitter to the receiver, the transit time difference t corresponding to the respective length difference L of the separate paths being only dependent on the mechanical structure of the acoustic tube itself and on the gas contained therein, but absolutely not on the sound transmitter or receiver.
  • Y is the adiabatic coefficient
  • T is the temperature [K]
  • the average molecular weight can be calculated.
  • the average molecular weight in turn determines the mixture ratios in a binary gas mixture.
  • Air for instance, can be understood as a mixture of dry air and water vapour.
  • the absolute humidity of unsaturated air can be calculated from the formula
  • p is the atmospheric pressure
  • M d is the molecular weight of dry air, i.e. 28,964; M H2 O is the molecular weight of water, i.e. 18,015; and is the average molecular weight calculated from the formula (1):
  • the second path needed in addition to the acoustic tube connection leading straight from the transmitter to the receiver, can be formed of a side branch placed in the atmosphere under measurement, so that the sound from the end of this side branch is reflected back to the main branch.
  • the back-and-forth nature of the procession of the sound prevents the gas flowing speed from affecting the sound speed.
  • the side branch may also be divided into several parallel side branches of identical lengths.
  • the gas contained in the branch must have a sufficient connection to the atmosphere under measurement in order to allow the sensor to react quickly to the changes in the atmosphere.
  • the autocorrelation function 1 of a sound signal recorded from one single transmitter shows two side peaks 2, 3, which are located symmetrically at the distance of the transit time difference t from the origin o, as is apparent from the appended drawing.
  • the average molecular weight of the gas mixture under measurement is calculated from the formula
  • the wideband sound signal In choosing the wideband sound signal, it must first of all be taken into account, that the simplest correlator only observes whether the signal is above or below its average (polarity correlator), but completely neglects the amplitude of the signal. Secondly it must be taken into account that while the sound proceeds in the gas-filled acoustic tube, high frequencies are clearly attenuated to a higher degree than low frequencies.
  • the wideband signal can be either noise-type or frequencyswept. High frequencies are particularly important while aiming at an accurate definition of the transit time difference.

Abstract

Un procédé, servant à définir le rapport de mélange dans un mélange de gaz binaire, se fonde sur un mesurage précis de la vitesse du son et de la température. Dans ledit procédé on fait progresser un signal sonore à bande large dans un tube acoustique rempli du gaz faisant l'objet du mesurage via deux chemins de longueurs différentes depuis un émetteur jusqu'à un récepteur et la différence de temps des transits (t) correspondant à la différence des longueurs (L) des chemins séparés est définie comme la distance s'étendant depuis l'origine 0 jusqu'aux crêtes latérales (2, 3) de la fonction d'autocorrélation du signal reçu. Le poids moléculaire moyen M(Boolean not) du mélange de gaz faisant l'objet du mesurage ainsi que les densités partielles des gaz de mélange sont calculés à partir des formules dérivées.
PCT/FI1987/000058 1986-05-02 1987-04-30 Procede permettant de definir le rapport de melange dans des melanges de gaz binaires WO1987006703A1 (fr)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
FI861857 1986-05-02
FI861857A FI74547C (fi) 1986-05-02 1986-05-02 Foerfarande foer faststaellande av en binaer gasblandnings blandningsproportion.

Publications (1)

Publication Number Publication Date
WO1987006703A1 true WO1987006703A1 (fr) 1987-11-05

Family

ID=8522557

Family Applications (1)

Application Number Title Priority Date Filing Date
PCT/FI1987/000058 WO1987006703A1 (fr) 1986-05-02 1987-04-30 Procede permettant de definir le rapport de melange dans des melanges de gaz binaires

Country Status (2)

Country Link
FI (1) FI74547C (fr)
WO (1) WO1987006703A1 (fr)

Cited By (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP0533980A1 (fr) * 1991-09-26 1993-03-31 Siemens Aktiengesellschaft Procédé pour déterminer la concentration des carburants ou de gaz dans l'air
US5392635A (en) * 1993-12-30 1995-02-28 At&T Corp. Acoustic analysis of gas mixtures
US5625140A (en) * 1995-12-12 1997-04-29 Lucent Technologies Inc. Acoustic analysis of gas mixtures
CN102914589A (zh) * 2012-09-29 2013-02-06 郑州光力科技股份有限公司 利用超声波检测甲烷浓度的检测方法

Citations (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE1812310A1 (de) * 1968-12-03 1970-06-18 Goecke Dipl Ing Dieter Akustischer Gasanalysator
US4003242A (en) * 1974-07-13 1977-01-18 A. Monforts Device for determining the mixing ratio of binary gases
GB2017299A (en) * 1978-02-10 1979-10-03 Leino M H Device for Measuring the Moisture content of the Exhaust Gas from a Drying Process
US4280183A (en) * 1978-08-04 1981-07-21 S.S.O.S. Sub Sea Oil Services S.P.A. Gas analyzer
DE3046081A1 (de) * 1980-12-06 1982-07-15 Kernforschungszentrum Karlsruhe Gmbh, 7500 Karlsruhe Akustischer gasanalysator
GB2146122A (en) * 1983-07-29 1985-04-11 Panametrics Measuring fluid flow parameters
EP0174627A2 (fr) * 1984-09-10 1986-03-19 Sumitomo Bakelite Company Limited Instrument pour mesurer la concentration d'un gaz

Patent Citations (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE1812310A1 (de) * 1968-12-03 1970-06-18 Goecke Dipl Ing Dieter Akustischer Gasanalysator
US4003242A (en) * 1974-07-13 1977-01-18 A. Monforts Device for determining the mixing ratio of binary gases
GB2017299A (en) * 1978-02-10 1979-10-03 Leino M H Device for Measuring the Moisture content of the Exhaust Gas from a Drying Process
US4280183A (en) * 1978-08-04 1981-07-21 S.S.O.S. Sub Sea Oil Services S.P.A. Gas analyzer
DE3046081A1 (de) * 1980-12-06 1982-07-15 Kernforschungszentrum Karlsruhe Gmbh, 7500 Karlsruhe Akustischer gasanalysator
GB2146122A (en) * 1983-07-29 1985-04-11 Panametrics Measuring fluid flow parameters
EP0174627A2 (fr) * 1984-09-10 1986-03-19 Sumitomo Bakelite Company Limited Instrument pour mesurer la concentration d'un gaz

Cited By (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP0533980A1 (fr) * 1991-09-26 1993-03-31 Siemens Aktiengesellschaft Procédé pour déterminer la concentration des carburants ou de gaz dans l'air
US5325703A (en) * 1991-09-26 1994-07-05 Siemens Aktiengesellschaft Method for identifying the concentration of fuels or gases
US5392635A (en) * 1993-12-30 1995-02-28 At&T Corp. Acoustic analysis of gas mixtures
US5501098A (en) * 1993-12-30 1996-03-26 At&T Corp. Acoustic analysis of gas mixtures
US5625140A (en) * 1995-12-12 1997-04-29 Lucent Technologies Inc. Acoustic analysis of gas mixtures
CN102914589A (zh) * 2012-09-29 2013-02-06 郑州光力科技股份有限公司 利用超声波检测甲烷浓度的检测方法
CN102914589B (zh) * 2012-09-29 2014-09-10 郑州光力科技股份有限公司 利用超声波检测甲烷浓度的检测方法

Also Published As

Publication number Publication date
FI74547C (fi) 1988-02-08
FI74547B (fi) 1987-10-30
FI861857A0 (fi) 1986-05-02

Similar Documents

Publication Publication Date Title
US4445389A (en) Long wavelength acoustic flowmeter
US5627323A (en) Ultrasonic binary gas measuring device
US4520320A (en) Synchronous phase marker and amplitude detector
EP0572581B1 (fr) Procede et dispositif de controle d'un ecoulement de gaz, plus specifiquement d'un ecoulement de gaz naturel
US4876889A (en) Acoustic humidity sensor
US5325703A (en) Method for identifying the concentration of fuels or gases
JPS6425025A (en) Detecting apparatus of leakage of water
US5583301A (en) Ultrasound air velocity detector for HVAC ducts and method therefor
WO1987006703A1 (fr) Procede permettant de definir le rapport de melange dans des melanges de gaz binaires
GB2087559A (en) Determining gas compositions acoustically
CA2026137A1 (fr) Methode pour determiner la distance et la direction de cibles sonores
EP1353173A2 (fr) Dispositif acoustique de surveillance des gaz
US4380167A (en) Apparatus and method for detecting a fraction of a gas
US4155246A (en) Rapid gas analyzing system
US4597285A (en) Humidity monitor and method
Zuckerwar et al. Resonant tube for measurement of sound absorption in gases at low frequency/pressure ratios
RU2186374C2 (ru) Способ измерения и контроля температуры точки росы влажного газа
Rouleau et al. Investigation of a microwave differential cavity resonator device for the measurement of humidity in gases
EP0758085A3 (fr) Procédés et appareil de détection de l'humidité
GB1302380A (fr)
RU56637U1 (ru) Акустический газоанализатор
RU2186365C2 (ru) Способ определения параметров пористости материалов
Brooks et al. Simple apparatus for concentration determinations in binary‐gas mixtures
SU1270582A1 (ru) Способ измерени скорости и затухани акустических волн в материале
SU1357827A1 (ru) Способ измерени скорости и затухани продольных упругих волн

Legal Events

Date Code Title Description
AK Designated states

Kind code of ref document: A1

Designated state(s): DK NO US

AL Designated countries for regional patents

Kind code of ref document: A1

Designated state(s): AT BE CH DE FR GB IT LU NL SE