EP1581331B1 - Device for synthesis of gas mixtures and use thereof for testing catalytic compositions - Google Patents

Device for synthesis of gas mixtures and use thereof for testing catalytic compositions Download PDF

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Publication number
EP1581331B1
EP1581331B1 EP02799763A EP02799763A EP1581331B1 EP 1581331 B1 EP1581331 B1 EP 1581331B1 EP 02799763 A EP02799763 A EP 02799763A EP 02799763 A EP02799763 A EP 02799763A EP 1581331 B1 EP1581331 B1 EP 1581331B1
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EP
European Patent Office
Prior art keywords
gas
pipe
flow
pipeline
mixing chamber
Prior art date
Legal status (The legal status 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 status listed.)
Expired - Lifetime
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EP02799763A
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German (de)
French (fr)
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EP1581331A1 (en
Inventor
Stéphane Melen
Gérard RENAUX
Bernard Grenouillet
Gérard Le Gouefflec
René Paul GAUCHER
Jean-Marc Fournier
Manuel Munoz
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LAir Liquide SA pour lEtude et lExploitation des Procedes Georges Claude
Original Assignee
Air Liquide SA
LAir Liquide SA a Directoire et Conseil de Surveillance pour lEtude et lExploitation des Procedes Georges Claude
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    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01F—MIXING, e.g. DISSOLVING, EMULSIFYING OR DISPERSING
    • B01F23/00—Mixing according to the phases to be mixed, e.g. dispersing or emulsifying
    • B01F23/10—Mixing gases with gases
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01F—MIXING, e.g. DISSOLVING, EMULSIFYING OR DISPERSING
    • B01F25/00—Flow mixers; Mixers for falling materials, e.g. solid particles
    • B01F25/10—Mixing by creating a vortex flow, e.g. by tangential introduction of flow components
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01F—MIXING, e.g. DISSOLVING, EMULSIFYING OR DISPERSING
    • B01F25/00—Flow mixers; Mixers for falling materials, e.g. solid particles
    • B01F25/30—Injector mixers
    • B01F25/31—Injector mixers in conduits or tubes through which the main component flows
    • B01F25/313—Injector mixers in conduits or tubes through which the main component flows wherein additional components are introduced in the centre of the conduit
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01F—MIXING, e.g. DISSOLVING, EMULSIFYING OR DISPERSING
    • B01F25/00—Flow mixers; Mixers for falling materials, e.g. solid particles
    • B01F25/40—Static mixers
    • B01F25/42—Static mixers in which the mixing is affected by moving the components jointly in changing directions, e.g. in tubes provided with baffles or obstructions
    • B01F25/43—Mixing tubes, e.g. wherein the material is moved in a radial or partly reversed direction
    • B01F25/433—Mixing tubes wherein the shape of the tube influences the mixing, e.g. mixing tubes with varying cross-section or provided with inwardly extending profiles
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01F—MIXING, e.g. DISSOLVING, EMULSIFYING OR DISPERSING
    • B01F25/00—Flow mixers; Mixers for falling materials, e.g. solid particles
    • B01F25/40—Static mixers
    • B01F25/42—Static mixers in which the mixing is affected by moving the components jointly in changing directions, e.g. in tubes provided with baffles or obstructions
    • B01F25/43—Mixing tubes, e.g. wherein the material is moved in a radial or partly reversed direction
    • B01F25/433—Mixing tubes wherein the shape of the tube influences the mixing, e.g. mixing tubes with varying cross-section or provided with inwardly extending profiles
    • B01F25/4338—Mixers with a succession of converging-diverging cross-sections, i.e. undulating cross-section
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01F—MIXING, e.g. DISSOLVING, EMULSIFYING OR DISPERSING
    • B01F35/00—Accessories for mixers; Auxiliary operations or auxiliary devices; Parts or details of general application
    • B01F35/20—Measuring; Control or regulation
    • B01F35/22—Control or regulation
    • B01F35/221—Control or regulation of operational parameters, e.g. level of material in the mixer, temperature or pressure
    • B01F35/2211—Amount of delivered fluid during a period
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01F—MIXING, e.g. DISSOLVING, EMULSIFYING OR DISPERSING
    • B01F2215/00—Auxiliary or complementary information in relation with mixing
    • B01F2215/04—Technical information in relation with mixing
    • B01F2215/0413—Numerical information
    • B01F2215/0418—Geometrical information
    • B01F2215/0431—Numerical size values, e.g. diameter of a hole or conduit, area, volume, length, width, or ratios thereof

Definitions

  • the invention relates to a device for synthesizing gas mixtures that can automatically produce specific gas mixtures defined by the nature of the gases that compose them, their flow rate and the temperature.
  • the gas mixture produced automatically and according to precise characteristics, both in nature of the gases, and the temperature or pressure of the mixture, is a known procedure for testing apparatuses or processes using these gas mixtures. This procedure is applied for example to test boilers or water heaters for which the gaseous mixtures used are particularly simple because they comprise only a few components.
  • the gaseous mixtures to be created in order to be able to test the catalytic compositions are particularly difficult to produce, firstly because they include many different gases in very different proportions, on the other hand because during the operation of an automobile engine, the composition of the exhaust gas varies significantly from one moment to another (start / deceleration or acceleration) as well as its temperature or flow rate.
  • Mixed gas devices typically used to test boilers can not be used to replicate such complex mixtures as automotive exhaust.
  • US-A-4,910,008 relates to a method and device for contacting at least two compounds in gaseous form, wherein the gases fed in collector channels and injected through orifices arranged in repetitive patterns in a chamber.
  • the channels are composed of two families of longitudinal and transverse gas feeders arranged relatively in such a way that they form repetitive pairs and neighbors of injection orifices.
  • US-A-4,861,165 relates to a method and means for hydrodynamic mixing in particular for mixtures comprising gaseous substances and fibrous substances in pastes or sludges.
  • This document describes a mixer comprising an axial channel for introducing the sludge and a tangential gas introduction channel. The mixture is subjected to turbulence by means of a succession of conical surfaces with sudden transitions.
  • US-A-5,129,412 relates to a mixer according to the preamble of the main claim of the gas mixture synthesis device.
  • An object of the present invention is therefore to provide a mixing device for synthesizing a gas mixture comprising many different gases in very different proportions.
  • Another aim is to propose a device for synthesizing a gas mixture having a variable composition over time both in nature of the gases that compose it, in temperature or in total flow and specific to each gas.
  • Another object is to provide a mixing device for synthesizing a homogeneous gas mixture.
  • the supply lines ensure the arrival of the gases to be mixed up to the mixing chamber. If certain fluids to be mixed are gaseous at ambient temperature, their supply lines are generally connected to the gas source by holders. On the other hand, if certain fluids are liquid at ambient temperature, their lines are connected to an evaporator making it possible to vaporize them and to convey them in gaseous form using a carrier gas such as nitrogen.
  • the evaporator is equipped with a temperature controller.
  • Supply lines are generally equipped with pneumatic and manual shut-off valves, as well as check valves and filters.
  • the computer controls the PLCs that control the flow controllers.
  • the supply lines can be equipped with a thermal oven, controlled by the computer, for setting the temperature of the gases to be mixed; the lines are then generally thermostated.
  • the shape of the straight sections of the injectors is circular, but it has been observed that the triangular or rhombic shapes can make it possible to obtain better mixtures.
  • the mixing chamber also comprises a static mixer placed in the extension of the pipe, that is to say after the injector connected to the secondary flow gas supply lines in the direction of gas flow.
  • a static mixer placed in the extension of the pipe, that is to say after the injector connected to the secondary flow gas supply lines in the direction of gas flow.
  • initial diameter is understood to mean the diameter of the pipe at the beginning of the first section, if this pipe is round.
  • the sequences of a convergent part and of a diverging part in the first section of the static mixer have a length of the order of an initial diameter, a length corresponding to the part of the pipe between two points where it has a diameter equal to the initial diameter and between which it converges then diverges:
  • the two convergent and divergent parts generally have the same length.
  • the minimum diameter of these convergent and divergent portion sequences at the most convergent point of the pipe is generally at least one-third of the value of the pipe. initial diameter.
  • the static mixer may comprise several successive sequences of a convergent portion and a divergent portion. This is for example the case when it is desired to mix fluids having a low Reynolds number.
  • each deformation leads to a pipe having in the cross-section of the crushing a section of ellipsoidal shape (if the pipe at the beginning of the second section is round).
  • Two successive deformations must be offset relative to each other by an angle between 10 and 45 °, preferably between 25 and 45 °, this angle corresponding to the angle formed between the directions of the straight lines. crushing each deformation.
  • the number of tightenings must be adapted to the nature of each mixture of fluids and to the subsequent use of the mixture, considering the fact that the greater the number of tightenings, the greater the pressure drop of the mixed fluids.
  • a tightening is carried out so that the minimum diameter of the pipe at the cross-section of the crushing is at least one third of the value of the initial diameter.
  • the length of a tightening may be for example of the order of the initial diameter.
  • the static mixer does not comprise an element forming an intrusion into its wall and penetrating into its pipe (such as fins) to form an obstacle to the passage of fluids, especially if the mixer makes it possible to treat fluids containing dust which may be deposited on these intrusive elements, or if the mixer can treat fluids whose temperature is desired to control, or if the mixer must treat corrosive gases.
  • an element forming an intrusion into its wall and penetrating into its pipe such as fins
  • the device according to the invention makes it possible to mix gases having flow rates of between 10 l / min and 800 l / min and main / secondary flow ratios of between 1 and 50. These flow rates can change over time to values such that the value of the total flow decreases or increases by 30%. It was found that a perfectly homogeneous mixture of different fluids could be obtained regardless of the value of these flows.
  • the quality control of the mixture is carried out using a probe analyzing, at the end of the pipe, the composition of the gas mixture along the entire length of a diameter of the pipe.
  • perfectly homogeneous mixing is therefore meant a mixture for which the composition is identical over the entire length of this diameter.
  • the assembly of the pipe and the static mixer may be surrounded by an external pipe having means for injecting a fluid into the interstice delimited by this external pipe and the outer wall of the pipe chamber. mixed.
  • the fluid is injected into this gap against the current of the fluids to be mixed.
  • the countercurrent fluid is generally an inert gas, preferably nitrogen.
  • the temperature of this fluid corresponds to that at which it is desired to maintain the gas mixture.
  • the present invention also relates to the use of the preceding device for testing catalytic compositions.
  • This device makes it possible to produce gaseous mixtures representative of industrial applications and which are subjected to catalytic treatments. The mixture at will of these gases makes it possible to test catalytic compositions.
  • the gas mixture analyzer leaving the mixing chamber and the computer controlling the controller that controls the flow regulators are coupled so as to adjust the composition of the gas mixture. This coupling makes it possible to avoid drifts due for example to the clogging of the device.
  • the catalytic composition test device may in particular be used to simulate an automobile engine exhaust gas composition and to test various depolluting catalysts.
  • the present invention finally relates to the use of the preceding device for calibrating analyzers.
  • This device makes it possible to produce gas mixtures, to subject these gaseous mixtures to precise catalytic treatments, the exact result of which is known on gaseous mixtures. By controlling the gas mixture compositions before and after catalytic treatment with analyzers, it is therefore possible to calibrate the analyzers.
  • FIGS 1 and 2 illustrate the mixing chamber of the device according to the invention.
  • a linear duct (1) with a diameter of 60 mm, one end of which is closed, is recognized.
  • a pipe (2) of diameter 10 mm and tangent to the pipe (1) penetrates tangentially into the pipe (1).
  • the main flow fluid is injected through this conduit (2).
  • a conduit (3) penetrates axially into the pipe (1).
  • the end of this duct (3), which enters the pipe (1), is pierced with a hole (4) for the injection of a secondary fluid axially to the pipe (1) via a pipe (41) .
  • the duct (3) is also radially pierced with 8 holes (5) of diameter 4 mm for the injection of secondary fluids, mixed or separately, radially in the pipe (1).
  • the device of the invention is used to reproduce a time varying automobile combustion exhaust gas mixture.
  • the desired mixture must have the following composition and flow rate characteristics: Product minimum flow (l / min) maximum flow (l / min) N 2 of main flow 10 500 O 2 0.1 100 CO 0.25 12.5 H 2 0.25 12.5 CO 2 0.5 100 SO 2 0,001 0.005 N 2 secondary flow 0,009 0,045 NO 0.005 0,125 NO 2 0.005 0,125 NH 3 0.01 0.2 H 2 O 0.5 15 CH 4 0,001 5 C 3 H 8 0.00025 1.25 C 3 H 6 0.00075 3.75 C 7 H 8 0,001 5 C 10 H 22 0,001 5
  • the liquid hydrocarbons and H 2 O are each vaporized at a temperature of 300 ° C in a stream of nitrogen.
  • the flow rate of each of the currents obtained is controlled by a flow regulator, then these streams are mixed in an isolated common supply line so as to avoid condensation of the vaporized products.
  • This line joins two other supply lines: that of the main flow nitrogen and that of SO 2 and CO 2 , which forms the main supply line, which enters the mixing chamber of Figure 1 by the led (2). This is the main flow gas.
  • the oxygen enters the mixing chamber of Figure 1 through the hole (4) of the conduit (3) (secondary flow).
  • the gaseous products CO, H 2 , NH 3 , the gaseous hydrocarbons, the secondary flow nitrogen are introduced through the same supply line into the duct (3) through four of the holes (5) of the duct (3) ( secondary flow)
  • NO is introduced by the other four holes (5) of the duct (3) (secondary flow).
  • the different supply lines for products to be mixed are all equipped with flow controllers controlled by PLCs.
  • the controllers are controlled by a computer programmed to implement the composition and flow rates of the table above to reproduce the engine cycle.
  • the control of the homogeneity of the mixture is carried out using an analysis sampling probe placed at the output of the dynamic mixer and analyzing at this point the composition of the fluid over the entire length of the diameter of the dynamic mixer.
  • an analysis sampling probe placed at the output of the dynamic mixer and analyzing at this point the composition of the fluid over the entire length of the diameter of the dynamic mixer.

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  • Chemical & Material Sciences (AREA)
  • Chemical Kinetics & Catalysis (AREA)
  • Dispersion Chemistry (AREA)
  • Investigating Or Analyzing Non-Biological Materials By The Use Of Chemical Means (AREA)
  • Sampling And Sample Adjustment (AREA)

Abstract

The invention concerns a device for synthesis of gas mixtures by mixing a main gas stream with a secondary gas stream. Said device comprises gas supply lines equipped with flow regulators and a mixing chamber wherein emerge the gas feed lines. The mixing chamber includes: a pipe connected to the feed line of the main gas stream so as to form a flow in the pipe and to the feed line of the secondary gas stream such that the secondary gas stream is introduced into the flow of the main gas stream, a static mixer arranged in the extension of the pipe. Said device can be used for testing catalytic compositions.

Description

L'invention concerne un dispositif de synthèse de mélanges de gaz pouvant produire de manière automatique des mélanges gazeux spécifiques définis par la nature des gaz qui les composent, leur débit et la température.The invention relates to a device for synthesizing gas mixtures that can automatically produce specific gas mixtures defined by the nature of the gases that compose them, their flow rate and the temperature.

Le mélange de gaz réalisé de manière automatique et selon des caractéristiques précises tant en nature des gaz qu'en température ou pression du mélange est une procédure connue pour tester des appareils ou des procédés mettant en oeuvre ces mélanges de gaz. Cette procédure est appliquée par exemple pour tester des chaudières ou des chauffe-eau pour lesquels les mélanges gazeux utilisés sont particulièrement simples car ils ne comprennent que quelques composants.The gas mixture produced automatically and according to precise characteristics, both in nature of the gases, and the temperature or pressure of the mixture, is a known procedure for testing apparatuses or processes using these gas mixtures. This procedure is applied for example to test boilers or water heaters for which the gaseous mixtures used are particularly simple because they comprise only a few components.

Dans d'autres domaines d'application tels que celui des réacteurs catalytiques pour le traitement des gaz d'échappement de combustion automobile, les mélanges gazeux à créer pour pouvoir tester les compositions catalytiques sont particulièrement difficiles à réaliser, d'une part parce qu'ils comprennent de nombreux gaz différents en proportions très différentes, d'autre part parce qu'au cours du fonctionnement d'un moteur automobile, la composition du gaz d'échappement varie de manière significative d'un instant à l'autre (démarrage/décélération ou accélération) de même que sa température ou son débit. Les dispositifs de mélangé de gaz classiquement utilisés pour tester des chaudières ne peuvent être utilisés pour reproduire les mélanges aussi complexes que les gaz d'échappement automobiles. En outre, il peut être important pour certains tests que les mélanges gazeux testés soient parfaitement homogènes. C'est le cas, par exemple, lorsque le mélange gazeux est passé au travers d'une pastille de catalyseur à tester : si la composition du mélange n'est pas homogène, tout le catalyseur ne réagit pas. Cette homogénéité du mélange est également importante pour contrôler si la composition du gaz désirée est bien obtenue : ce contrôle est réalisé à l'aide d'un analyseur dont la sonde plonge dans le mélangé gazeux ; un mauvais mélange conduira à un contrôle faux.In other fields of application such as that of catalytic reactors for the treatment of automobile combustion exhaust gases, the gaseous mixtures to be created in order to be able to test the catalytic compositions are particularly difficult to produce, firstly because they include many different gases in very different proportions, on the other hand because during the operation of an automobile engine, the composition of the exhaust gas varies significantly from one moment to another (start / deceleration or acceleration) as well as its temperature or flow rate. Mixed gas devices typically used to test boilers can not be used to replicate such complex mixtures as automotive exhaust. In addition, it may be important for some tests that the gas mixtures tested be perfectly homogeneous. This is the case, for example, when the gaseous mixture is passed through a catalyst pellet to be tested: if the composition of the mixture is not homogeneous, all the catalyst does not react. This homogeneity of the mixture is also important to control whether the composition of the desired gas is well obtained: this control is carried out using an analyzer whose probe is immersed in the gaseous mixture; a bad mix will lead to a wrong check.

Le document US-A-4,910,008 concerne un procédé et dispositif de mise en contact d'au moins deux composés sous forme gazeuse, dans lequel les gaz amenés selon des canaux collecteurs et injectés à travers des orifices disposés selon des motifs répétitifs dans une chambre. Les canaux sont composés de deux familles d'amenées de gaz longitudinales et transversales disposées relativement de manière telle qu'elles forment des couples répétitifs et voisins d'orifices d'injection.US-A-4,910,008 relates to a method and device for contacting at least two compounds in gaseous form, wherein the gases fed in collector channels and injected through orifices arranged in repetitive patterns in a chamber. The channels are composed of two families of longitudinal and transverse gas feeders arranged relatively in such a way that they form repetitive pairs and neighbors of injection orifices.

Le document US-A-4,861,165 concerne une méthode et des moyens de mélange hydrodynamique en particulier pour des mélanges comprenant des substances gazeuses et des substances fibreuses dans des pâtes ou boues. Ce document décrit un mélangeur comprenant un canal axial d'introduction de la boue et un canal tangentiel d'introduction de gaz. Le mélange est soumis à une turbulence au moyen d'une succession de surfaces coniques à transitions brusques.US-A-4,861,165 relates to a method and means for hydrodynamic mixing in particular for mixtures comprising gaseous substances and fibrous substances in pastes or sludges. This document describes a mixer comprising an axial channel for introducing the sludge and a tangential gas introduction channel. The mixture is subjected to turbulence by means of a succession of conical surfaces with sudden transitions.

Le document US-A-5,129,412 concerne un mélangeur conforme au préambule de la revendication principale du dispositif de synthèse de mélange gazeux.US-A-5,129,412 relates to a mixer according to the preamble of the main claim of the gas mixture synthesis device.

Un but de la présente invention est donc de proposer un dispositif de mélange permettant de synthétiser un mélange gazeux comprenant de nombreux gaz différents en proportions très différentes.An object of the present invention is therefore to provide a mixing device for synthesizing a gas mixture comprising many different gases in very different proportions.

Un autre but est de proposer un dispositif permettant de synthétiser un mélange gazeux présentant une composition variable dans le temps tant en nature des gaz qui le composent, qu'en température ou encore en débit total et spécifique à chaque gaz.Another aim is to propose a device for synthesizing a gas mixture having a variable composition over time both in nature of the gases that compose it, in temperature or in total flow and specific to each gas.

Un autre but est de proposer un dispositif de mélange permettant de synthétiser un mélange gazeux homogène.Another object is to provide a mixing device for synthesizing a homogeneous gas mixture.

Dans ces buts, l'invention concerne un dispositif de synthèse de mélanges gazeux conforme au préambule de la revendication 1 comprenant :

  • au moins deux lignes d'approvisionnement en gaz,
  • au moins deux régulateurs de débit coopérant chacun avec les lignes d'approvisionnement en gaz,
  • une chambre de mélange dans laquelle débouchent les lignes d'approvisionnement en gaz, ladite chambre de mélange comprenant :
    • une conduite :
      • ➢ connectée à la ligne d'approvisionnement du gaz de débit principal de manière à ce que ce gaz forme un écoulement dans la conduite,
      • ➢ connectée aux lignes d'approvisionnement des gaz de débit secondaire par au moins un injecteur de manière à ce que les gaz de débit secondaire soient introduits dans l'écoulement du gaz de débit principal
    • un mélangeur statique placé dans la prolongation de la conduite.
For these purposes, the invention relates to a gas mixture synthesis device according to the preamble of claim 1 comprising:
  • at least two gas supply lines,
  • at least two flow regulators each cooperating with the gas supply lines,
  • a mixing chamber into which the gas supply lines open, said mixing chamber comprising:
    • a conduct :
      • ➢ connected to the main flow gas supply line so that this gas forms a flow in the pipe,
      • ➢ connected to the secondary flow gas supply lines by at least one injector so that the secondary flow gases are introduced into the flow of the main flow gas
    • a static mixer placed in the extension of the pipe.

Le dispositif de synthèse de mélange gazeux est caractérisé en ce qu'il comprend au moins un automate contrôlé par un calculateur pour piloter les régulateurs de débit et en ce que le mélangeur statique est une canalisation se composant successivement :

  • d'une première section constituée d'une partie convergente (6) puis une partie divergente (7), puis
  • d'une deuxième section comprenant au moins deux resserrements (8, 9) de la canalisation,
    • . chaque resserrement étant obtenu par écrasement radial de la canalisation dans une direction, et
    • . lesdits resserrements étant décalés l'un par rapport à l'autre d'un angle compris entre 10 et 45°, puis
  • d'une troisième section constituée d'au moins un enchaînement d'une partie convergente (10) puis d'une partie divergente (11).
The gas mixture synthesis device is characterized in that it comprises at least one controller controlled by a computer for controlling the flow regulators and in that the static mixer is a pipe successively consisting of:
  • of a first section consisting of a convergent part (6) then a divergent part (7), then
  • a second section comprising at least two constrictions (8, 9) of the pipe,
    • . each constriction being obtained by radially crushing the pipe in one direction, and
    • . said constrictions being offset relative to each other by an angle of between 10 and 45 °, and then
  • a third section consisting of at least one concatenation of a convergent portion (10) and a divergent portion (11).

Les lignes d'approvisionnement assurent l'arrivée des gaz à mélanger jusqu'à la chambre de mélange. Si certains fluides à mélanger sont gazeux à température ambiante, leurs lignes d'approvisionnement sont généralement reliées à la source de gaz par des détenteurs. Par contre, si certains fluide sont liquides à température ambiante, leurs lignes sont reliées à un évaporateur permettant de les vaporiser et de les véhiculer sous forme gazeuse à l'aide d'un gaz porteur tel que l'azote. L'évaporateur est équipé d'un régulateur de température.The supply lines ensure the arrival of the gases to be mixed up to the mixing chamber. If certain fluids to be mixed are gaseous at ambient temperature, their supply lines are generally connected to the gas source by holders. On the other hand, if certain fluids are liquid at ambient temperature, their lines are connected to an evaporator making it possible to vaporize them and to convey them in gaseous form using a carrier gas such as nitrogen. The evaporator is equipped with a temperature controller.

Les lignes d'approvisionnement sont généralement équipées de vannes d'arrêt pneumatiques et manuelles, ainsi que de clapets anti-retour et de filtres.Supply lines are generally equipped with pneumatic and manual shut-off valves, as well as check valves and filters.

Les lignes d'approvisionnement sont équipées de régulateurs de débit de manière à fixer les valeurs des débits des gaz à mélanger. Il s'agit généralement de régulateurs de débit massique. Si un fluide à mélanger est liquide à température ambiante et doit être vaporisé, des régulateurs de débit sont placés à la fois sur la ligne d'approvisionnement en liquide de l'évaporateur et sur la ligne d'approvisionnement en gaz porteur de l'évaporateur. Pour ces lignes, il est généralement prévu, après l'évaporateur, la mise en place d'un cordon chauffeur pour éviter la condensation du liquide vaporisé lors de son transport. Les régulateurs de débit sont pilotés par un automate contrôlé par un calculateur. Ainsi, pour chaque régulateur de débit, le calculateur calcule la consigne de débit, lit la valeur réelle résultant de cette consigne, ouvre la vanne du régulateur associée, vérifie que la valeur mesurée est conforme à la consigne appliquée. Le calculateur est relié à :

  • des instructions concernant le mélange de gaz à effectuer (nature des gaz, proportion, débit du mélange final, température) et qui sont caractéristiques du mélange à reproduire,
  • des bases de données sur les propriétés des gaz à mélanger : diagramme de phase, risque d'inflammabilité seul ou en mélange.
The supply lines are equipped with flow regulators to set the values of the flow rates of the gases to be mixed. These are usually mass flow controllers. If a fluid to be mixed is liquid at room temperature and must be vaporized, flow regulators are placed both on the liquid supply line of the evaporator and on the gas supply line of the evaporator. . For these lines, it is generally expected, after the evaporator, the introduction of a conductor cord to prevent condensation of the vaporized liquid during transport. Flow controllers are controlled by a controller controlled by a computer. Thus, for each flow controller, the computer calculates the flow setpoint, reads the actual value resulting from this setpoint, opens the valve of the associated controller, checks that the measured value complies with the setpoint applied. The calculator is connected to:
  • instructions concerning the mixture of gases to be carried out (nature of the gases, proportion, rate of the final mixture, temperature) and which are characteristic of the mixture to be reproduced,
  • databases on the properties of the gases to be mixed: phase diagram, flammability risk alone or mixed.

En fonction des instructions données, le calculateur contrôle les automates qui pilotent les régulateurs de débit.Depending on the instructions given, the computer controls the PLCs that control the flow controllers.

Les lignes d'approvisionnement peuvent être équipées d'un four thermique, contrôlé par le calculateur, permettant de fixer la température des gaz à mélanger ; les lignes sont alors généralement thermostatées.The supply lines can be equipped with a thermal oven, controlled by the computer, for setting the temperature of the gases to be mixed; the lines are then generally thermostated.

Plusieurs lignes d'approvisionnement peuvent se rejoindre pour ne former qu'une seule ligne, par exemple lorsqu'il s'agit de lignes véhiculant des gaz dont le débit ou la température sont proches. Dans le cas où des lignes se rejoignent et où la température des gaz doit être fixée, il est alors préférable de placer le four thermique sur la ligne finale dans laquelle plusieurs gaz sont présents. Toutefois, il est préférable que les gaz dont le mélange présente des risques d'inflammabilité soient introduits par des lignes d'approvisionnement différentes.Several supply lines can join to form a single line, for example when it comes to lines carrying gas whose flow or temperature are close. In the case where lines meet and where the temperature of the gases must be fixed, it is then preferable to place the thermal oven on the final line in which several gases are present. However, it is preferable that gases whose mixture presents risks of flammability are introduced by different supply lines.

Les lignes d'approvisionnement en gaz débouchent dans la chambre de mélange, qui comprend une conduite et un mélangeur statique. Les lignes d'approvisionnement sont différemment connectées à la conduite selon la nature des débits des gaz qui y sont véhiculés. Ainsi, la ligne d'approvisionnement qui véhicule le gaz de débit principal (c'est-à-dire le gaz de débit le plus grand) débouche dans la conduite de la chambre de mélange de manière à ce que ce gaz de débit principal forme un écoulement dans la conduite. Cet écoulement peut être avantageusement obtenu par l'introduction du gaz principal de manière tangentielle dans la conduite, par exemple par une conduite d'injection débouchant tangentiellement dans la conduite. La ou les ligne(s) d'approvisionnement en gaz de débit secondaire (c'est-à-dire les gaz présentant un débit inférieur au débit principal) débouche(nt) dans la conduite de la chambre de mélange par l'intermédiaire d'au moins un injecteur de manière à ce que les gaz de débits secondaires soient introduits dans l'écoulement du gaz principal. Par injecteur, on entend un orifice d'accès à la conduite de la chambre de mélange. Cet orifice peut être situé au bord ou au milieu de la conduite. Il peut s'agir de tout type d'injecteur. Il présente de préférence une forme calculée pour l'injection d'un gaz de faible débit. Par exemple, il peut s'agir d'un injecteur débouchant au milieu de la conduite et injectant au moins un gaz de débit secondaire de manière axiale dans la conduite. Il peut également s'agir d'un injecteur à jet présentant un effet à écoulement azimutal (dit "swirl" en anglais) en périphérie. Cet effet permet la création d'une turbulence favorisant le mélange par cisaillement. Un injecteur dont l'axe d'injection présente un angle de 90° avec l'axe de la conduite, une extrémité d'éjection co-axiale à la conduite et une composante azimutale comprise entre 15 et 90° est particulièrement recommandé. Il peut par exemple s'agir de l'injecteur décrit dans la demande de brevet EP-A-0 474 524. Il peut également s'agir d'une pluralité d'injecteurs à jet, par exemple disposés dans la même section droite de la conduite sous forme d'une couronne. Plusieurs injecteurs tels que ceux cités précédemment peuvent être utilisés simultanément pour introduire différents gaz de débit secondaire dans le flux de gaz de débit principal. Ainsi, selon une mise en oeuvre particulière de l'invention :

  • le gaz de débit principal est introduit dans la conduite par un injecteur débouchant tangentiellement dans la conduite,
  • une partie des gaz secondaires (de préférence le gaz oxygéné, si un gaz oxygéné est un gaz de débit secondaire), sont injectés de manière axiale au centre de la conduite, et
  • l'autre partie des gaz secondaires sont injectés par une pluralité d'injecteurs tous disposés dans la même section droite de la conduite sous forme d'une couronne. Ces gaz secondaires peuvent être prémélangés, le prémélange obtenu étant ensuite introduit dans les injecteurs placés en forme de couronne ; ces gaz peuvent également être introduits séparément dans des injecteurs différents de la couronne.
The gas supply lines open into the mixing chamber, which includes a pipe and a static mixer. The supply lines are differently connected to the pipe according to the nature of the flow rates of the gases that are conveyed there. Thus, the supply line that conveys the main flow gas (ie the largest flow gas) leads to the driving the mixing chamber so that this main flow gas forms a flow in the pipe. This flow can be advantageously obtained by the introduction of the main gas tangentially in the pipe, for example by an injection pipe opening tangentially into the pipe. The secondary flow gas supply line (s) (i.e., the gases having a flow rate lower than the main flow rate) opens (s) into the pipe of the mixing chamber via at least one injector so that the secondary flow gases are introduced into the flow of the main gas. Injector means a port for access to the pipe of the mixing chamber. This orifice may be located at the edge or in the middle of the pipe. It can be any type of injector. It preferably has a calculated form for the injection of a low flow gas. For example, it may be an injector opening in the middle of the pipe and injecting at least one secondary flow gas axially in the pipe. It may also be a jet injector having an effect to flow azimuthal (called "swirl" in English) periphery. This effect allows the creation of a turbulence promoting shear mixing. An injector whose injection axis has an angle of 90 ° with the axis of the pipe, a coaxial ejection end to the pipe and an azimuthal component between 15 and 90 ° is particularly recommended. It may for example be the injector described in the patent application EP-A-0 474 524. It may also be a plurality of jet injectors, for example arranged in the same cross section of driving in the form of a crown. Several injectors such as those mentioned above can be used simultaneously to introduce different secondary flow gases into the main flow gas stream. Thus, according to one particular embodiment of the invention:
  • the main flow gas is introduced into the pipe by an injector opening tangentially into the pipe,
  • a part of the secondary gases (preferably the oxygenated gas, if an oxygenated gas is a secondary flow gas), are injected axially in the center of the pipe, and
  • the other part of the secondary gases are injected by a plurality of injectors all arranged in the same straight section of the pipe in the form of a ring. These secondary gases can be premixed, the premix obtained then being introduced into the injectors placed in the form of a ring; these gases can also be introduced separately into different injectors of the crown.

Généralement, la forme des sections droites des injecteurs est circulaire, mais il a été observé que les formes triangulaires ou de losange peuvent permettre d'obtenir de meilleurs mélanges.Generally, the shape of the straight sections of the injectors is circular, but it has been observed that the triangular or rhombic shapes can make it possible to obtain better mixtures.

La chambre de mélange comprend également un mélangeur statique placé dans la prolongation de la conduite, c'est-à-dire après l'injecteur connecté aux lignes d'approvisionnement des gaz de débit secondaire selon le sens d'écoulement des gaz. Cette combinaison d'un mélangeur statique et de la conduite permet d'atteindre le but fixé par la présente invention alors qu'aucun de ces derniers dispositifs pris séparément ne le permettait.The mixing chamber also comprises a static mixer placed in the extension of the pipe, that is to say after the injector connected to the secondary flow gas supply lines in the direction of gas flow. This combination of a static mixer and the pipe makes it possible to achieve the goal set by the present invention when none of these latter devices taken separately allowed it.

Dans la suite de la description, on entend par diamètre initial, le diamètre de la canalisation au début de la première section, si cette canalisation est ronde.In the remainder of the description, initial diameter is understood to mean the diameter of the pipe at the beginning of the first section, if this pipe is round.

En général, les enchaînements d'une partie convergente et d'une partie divergente dans la première section du mélangeur statique présentent une longueur de l'ordre d'un diamètre initial, une longueur correspondant à la partie de la canalisation comprise entre deux points où elle présente un diamètre égal au diamètre initial et entre lesquels elle converge puis diverge: Les deux parties convergente et divergente présentent généralement la même longueur. Le diamètre minimal de ces enchaînements de parties convergente et divergente au point le plus convergent de la canalisation est généralement d'au moins un tiers de la valeur du diamètre initial. Dans la troisième section du mélangeur statique, on applique les mêmes règles aux enchaînements de partie convergente et de partie divergente que pour la première section. Dans une même première ou troisième section, le mélangeur statique peut comprendre plusieurs enchaînements successifs d'une partie convergente et d'une partie divergente. C'est par exemple le cas lorsque l'on souhaite mélanger des fluides présentant un nombre de Reynolds faible.In general, the sequences of a convergent part and of a diverging part in the first section of the static mixer have a length of the order of an initial diameter, a length corresponding to the part of the pipe between two points where it has a diameter equal to the initial diameter and between which it converges then diverges: The two convergent and divergent parts generally have the same length. The minimum diameter of these convergent and divergent portion sequences at the most convergent point of the pipe is generally at least one-third of the value of the pipe. initial diameter. In the third section of the static mixer, the same rules are applied to the convergent part and divergent part sequences as for the first section. In the same first or third section, the static mixer may comprise several successive sequences of a convergent portion and a divergent portion. This is for example the case when it is desired to mix fluids having a low Reynolds number.

Dans la deuxième section, chaque déformation conduit à une canalisation présentant dans la section droite de l'écrasement à une section de forme ellipsoïdale (si la canalisation au début de la deuxième section est ronde). Deux déformations successives doivent être décalées l'une par rapport à l'autre d'un angle compris entre 10 et 45°, de préférence compris entre 25 et 45°, cet angle correspondant à l'angle formé entre les directions des droites d'écrasement de chaque déformation. Le nombre de resserrements doit être adapté à la nature de chaque mélange de fluides et à l'utilisation ultérieure du mélange, en considérant le fait que plus le nombre de resserrements sera grand, plus la perte de charge des fluides mélangés sera grande. En général, un resserrement est réalisé de manière à ce que le diamètre minimal de la canalisation au niveau de la section droite de l'écrasement soit d'au moins un tiers de la valeur du diamètre initial. La longueur d'un resserrement peut être par exemple de l'ordre du diamètre initial.In the second section, each deformation leads to a pipe having in the cross-section of the crushing a section of ellipsoidal shape (if the pipe at the beginning of the second section is round). Two successive deformations must be offset relative to each other by an angle between 10 and 45 °, preferably between 25 and 45 °, this angle corresponding to the angle formed between the directions of the straight lines. crushing each deformation. The number of tightenings must be adapted to the nature of each mixture of fluids and to the subsequent use of the mixture, considering the fact that the greater the number of tightenings, the greater the pressure drop of the mixed fluids. In general, a tightening is carried out so that the minimum diameter of the pipe at the cross-section of the crushing is at least one third of the value of the initial diameter. The length of a tightening may be for example of the order of the initial diameter.

De préférence, le mélangeur statique ne comprend pas d'élément formant une intrusion dans sa paroi et pénétrant dans sa canalisation (tel que des ailettes) pour former un obstacle au passage des fluides, notamment si le mélangeur permet de traiter des fluides contenant des poussières qui pourraient se déposer sur ces éléments intrusifs, ou si le mélangeur permet de traiter des fluides dont on souhaite contrôler la température, ou encore si le mélangeur doit traiter des gaz corrosifs.Preferably, the static mixer does not comprise an element forming an intrusion into its wall and penetrating into its pipe (such as fins) to form an obstacle to the passage of fluids, especially if the mixer makes it possible to treat fluids containing dust which may be deposited on these intrusive elements, or if the mixer can treat fluids whose temperature is desired to control, or if the mixer must treat corrosive gases.

Le dispositif selon l'invention permet de mélanger des gaz présentant des débits compris entre 10 l/min et 800 l/min et des rapports de débits principal/secondaire compris entre 1 et 50. Ces débits peuvent évoluer dans le temps jusqu'à des valeurs telles que la valeur du débit total diminue ou augmente de 30 %. Il a été constaté qu'un mélange parfaitement homogène des différents fluides a pu être obtenu quelle que soit la valeur de ces débits. Le contrôle de la qualité du mélange est effectué à l'aide d'une sonde analysant, en fin de canalisation, la composition du mélange gazeux sur toute la longueur d'un diamètre de la canalisation. Par mélange parfaitement homogène, on entend donc un mélange pour lequel la composition est identique sur toute la longueur de ce diamètre.The device according to the invention makes it possible to mix gases having flow rates of between 10 l / min and 800 l / min and main / secondary flow ratios of between 1 and 50. These flow rates can change over time to values such that the value of the total flow decreases or increases by 30%. It was found that a perfectly homogeneous mixture of different fluids could be obtained regardless of the value of these flows. The quality control of the mixture is carried out using a probe analyzing, at the end of the pipe, the composition of the gas mixture along the entire length of a diameter of the pipe. By perfectly homogeneous mixing is therefore meant a mixture for which the composition is identical over the entire length of this diameter.

Selon une variante, l'ensemble de la conduite et du mélangeur statique peut être entouré d'une canalisation extérieure présentant des moyens pour l'injection d'un fluide dans l'interstice délimité par cette canalisation extérieure et la paroi externe de la chambre de mélange. Le fluide est injecté dans cet interstice à contre-courant des fluides à mélanger. Le fluide à contre-courant est généralement un gaz inerte, de préférence de l'azote. La température de ce fluide correspond à celle à laquelle on souhaite maintenir le mélange de gaz. Cette variante utilisant un gaz inerte à contre-courant des fluides à traiter permet de réguler la température des gaz en cours de mélange de manière efficace. La température peut être maintenue ou modifiée très rapidement ; ainsi, cette mise en oeuvre permet de varier la température de +/- 5°C par seconde pour une gamme de température comprise entre 60 et 600°C.According to a variant, the assembly of the pipe and the static mixer may be surrounded by an external pipe having means for injecting a fluid into the interstice delimited by this external pipe and the outer wall of the pipe chamber. mixed. The fluid is injected into this gap against the current of the fluids to be mixed. The countercurrent fluid is generally an inert gas, preferably nitrogen. The temperature of this fluid corresponds to that at which it is desired to maintain the gas mixture. This variant using an inert gas against the current of the fluids to be treated makes it possible to regulate the temperature of the gases during mixing effectively. The temperature can be maintained or changed very quickly; thus, this implementation makes it possible to vary the temperature of +/- 5 ° C per second for a temperature range between 60 and 600 ° C.

La présente invention concerne également l'utilisation du dispositif précédent pour tester des compositions catalytiques. Ce dispositif permet en effet de réaliser des mélanges gazeux représentatifs d'applications industrielles et qui sont soumis à des traitements catalytiques. Le mélange à volonté de ces gaz permet de tester des compositions catalytiques.The present invention also relates to the use of the preceding device for testing catalytic compositions. This device makes it possible to produce gaseous mixtures representative of industrial applications and which are subjected to catalytic treatments. The mixture at will of these gases makes it possible to test catalytic compositions.

Dans ce contexte, l'invention concerne plus particulièrement un dispositif de test de compositions catalytiques mettant en oeuvre des réactions avec des mélanges de gaz comprenant un dispositif de synthèse de mélange gazeux conforme à l'une quelconque des caractéristiques ci-dessus, le dispositif de test comprenant en outre

  • un analyseur placé à la sortie de la chambre de mélange,
  • une chambre réactionnelle comprenant des moyens pour la mise en contact du mélange de gaz et du catalyseur à tester,
  • un analyseur du mélange de gaz sortant de la chambre réactionnelle.
In this context, the invention relates more particularly to a device for testing catalytic compositions using reactions with gas mixtures comprising a gas mixture synthesis device according to any one of the above characteristics, the device for test further comprising
  • an analyzer placed at the outlet of the mixing chamber,
  • a reaction chamber comprising means for contacting the gas mixture with the catalyst to be tested,
  • an analyzer of the gas mixture leaving the reaction chamber.

Le dispositif de test correspond au dispositif de mélange précédemment décrit auquel est ajouté :

  • un premier analyseur de gaz permettant de contrôler la nature du mélange de gaz à la sortie de la chambre de mélange,
  • une chambre réactionnelle dans laquelle le catalyseur à tester est mis en contact avec le mélange de gaz réalisé dans la chambre de mélange,
  • un deuxième analyseur de gaz permettant de contrôler la nature du mélange de gaz à la sortie de la chambre réactionnelle en vue de l'analyse de l'efficacité du catalyseur testé par comparaison avec la nature du mélange de gaz à la sortie de la chambre de mélange.
The test device corresponds to the previously described mixing device to which is added:
  • a first gas analyzer for controlling the nature of the gas mixture at the outlet of the mixing chamber,
  • a reaction chamber in which the catalyst to be tested is brought into contact with the gas mixture produced in the mixing chamber,
  • a second gas analyzer making it possible to control the nature of the gas mixture at the outlet of the reaction chamber in order to analyze the effectiveness of the tested catalyst compared with the nature of the gas mixture at the outlet of the chamber of mixed.

Selon un mode préférentiel, l'analyseur du mélange de gaz sortant de la chambre de mélange et le calculateur contrôlant l'automate qui pilote les régulateurs de débit sont couplés de manière à ajuster la composition du mélange de gaz. Ce couplage permet d'éviter les dérives dues par exemple à l'encrassage du dispositif.In a preferred embodiment, the gas mixture analyzer leaving the mixing chamber and the computer controlling the controller that controls the flow regulators are coupled so as to adjust the composition of the gas mixture. This coupling makes it possible to avoid drifts due for example to the clogging of the device.

Le dispositif de test de composition catalytique peut être notamment utilisé pour simuler une composition de gaz d'échappement de moteur automobile et tester différents catalyseurs dépolluants.The catalytic composition test device may in particular be used to simulate an automobile engine exhaust gas composition and to test various depolluting catalysts.

La présente invention concerne enfin l'utilisation du dispositif précédent pour étalonner des analyseurs. Ce dispositif permet en effet de réaliser des mélanges gazeux, de soumettre ces mélanges gazeux à des traitements catalytiques précis, dont on connaît exactement le résultat sur les mélanges gazeux. En contrôlant par des analyseurs les compositions du mélange gazeux avant et après traitement catalytique, il est donc possible d'étalonner les analyseurs.The present invention finally relates to the use of the preceding device for calibrating analyzers. This device makes it possible to produce gas mixtures, to subject these gaseous mixtures to precise catalytic treatments, the exact result of which is known on gaseous mixtures. By controlling the gas mixture compositions before and after catalytic treatment with analyzers, it is therefore possible to calibrate the analyzers.

Les figures 1 et 2 illustrent la chambre de mélange du dispositif selon l'invention. On reconnaît sur ces figures, une canalisation linéaire (1) de diamètre 60 mm dont une extrémité est fermée. A l'extrémité fermée de cette canalisation (1), un conduit (2) de diamètre 10 mm et tangent à la canalisation (1) pénètre tangentiellement dans la canalisation (1). Le fluide de débit principal est injecté par ce conduit (2). En outre, à cette l'extrémité fermée de la canalisation (1), un conduit (3) pénètre axialement dans la canalisation (1). L'extrémité de ce conduit (3), qui pénètre dans la canalisation (1), est percée d'un trou (4) pour l'injection d'un fluide secondaire axialement à la canalisation (1) via une canalisation (41). A cette même extrémité du conduit (3), le conduit (3) est également radialement percé de 8 trous (5) de diamètre 4 mm pour l'injection de fluides secondaires, mélangés ou séparément, radialement dans la canalisation (1).Figures 1 and 2 illustrate the mixing chamber of the device according to the invention. In these figures, a linear duct (1) with a diameter of 60 mm, one end of which is closed, is recognized. At the closed end of this pipe (1), a pipe (2) of diameter 10 mm and tangent to the pipe (1) penetrates tangentially into the pipe (1). The main flow fluid is injected through this conduit (2). In addition, at this closed end of the pipe (1), a conduit (3) penetrates axially into the pipe (1). The end of this duct (3), which enters the pipe (1), is pierced with a hole (4) for the injection of a secondary fluid axially to the pipe (1) via a pipe (41) . At this same end of the duct (3), the duct (3) is also radially pierced with 8 holes (5) of diameter 4 mm for the injection of secondary fluids, mixed or separately, radially in the pipe (1).

La canalisation (1) se poursuit par un mélangeur statique composé :

  • d'une première section, de longueur 60 mm, constituée d'une section convergente (6) passant d'un diamètre initial de 60 mm à un diamètre minimal de 20 mm et d'une section divergente (7) passant du diamètre minimal de 20 mm à un diamètre maximal de 60 mm,
  • d'une deuxième section constituée :
  • d'une première partie de longueur 60 mm comprenant une déformation radiale (8) de section minimale 20 mm, et
  • d'une deuxième partie de longueur 60 mm comprenant une déformation radiale (9) de diamètre minimal 20 mm, cette deuxième déformation étant obtenue par écrasement de la section droite de la canalisation entre deux droites parallèles dont la direction fait un angle de 45° avec la direction des deux droites parallèles conduisant à la première déformation,
  • d'une troisième section constituée d'une section convergente (10) passant d'un diamètre initial de 60 mm à un diamètre minimal de 20 mm et d'une section divergente (11) passant du diamètre minimal de 20 mm à un diamètre maximal de 60 mm.
The pipe (1) continues with a static mixer composed:
  • a first section, 60 mm long, consisting of a converging section (6) passing from an initial diameter of 60 mm to a minimum diameter of 20 mm and a diverging section (7) passing from the minimum diameter of 20 mm to a maximum diameter of 60 mm,
  • a second section constituted:
  • a first portion of length 60 mm comprising a radial deformation (8) of minimum section 20 mm, and
  • a second portion of length 60 mm comprising a radial deformation (9) of minimum diameter 20 mm, this second deformation being obtained by crushing the cross section of the pipe between two parallel straight lines whose direction is at an angle of 45 ° with the direction of the two parallel lines leading to the first deformation,
  • a third section consisting of a converging section (10) passing from an initial diameter of 60 mm to a minimum diameter of 20 mm and a diverging section (11) passing from the minimum diameter of 20 mm to a maximum diameter 60 mm.

ExempleExample

Le dispositif de l'invention est utilisé pour reproduire un mélange de gaz d'échappement de combustion automobile variant dans le temps. Le mélange désiré doit présenter les caractéristiques de compositions et de variations de débits suivantes : Produit débit minimal (l/min) débit maximal (l/min) N2 de débit principal 10 500 O2 0,1 100 CO 0,25 12,5 H2 0,25 12,5 CO2 0,5 100 SO2 0,001 0,005 N2 de débit secondaire 0,009 0,045 NO 0,005 0,125 NO2 0,005 0,125 NH3 0,01 0,2 H2O 0,5 15 CH4 0,001 5 C3H8 0,00025 1,25 C3H6 0,00075 3,75 C7H8 0,001 5 C10H22 0,001 5 The device of the invention is used to reproduce a time varying automobile combustion exhaust gas mixture. The desired mixture must have the following composition and flow rate characteristics: Product minimum flow (l / min) maximum flow (l / min) N 2 of main flow 10 500 O 2 0.1 100 CO 0.25 12.5 H 2 0.25 12.5 CO 2 0.5 100 SO 2 0,001 0.005 N 2 secondary flow 0,009 0,045 NO 0.005 0,125 NO 2 0.005 0,125 NH 3 0.01 0.2 H 2 O 0.5 15 CH 4 0,001 5 C 3 H 8 0.00025 1.25 C 3 H 6 0.00075 3.75 C 7 H 8 0,001 5 C 10 H 22 0,001 5

Ces variations de débit sont réalisées selon un cycle moteur défini.These flow variations are performed according to a defined motor cycle.

Afin d'être mélangés sous forme gazeuse, les hydrocarbures liquides et H2O sont chacun vaporisés à une température de 300°C dans un courant d'azote. Le débit de chacun des courants obtenus est contrôlé par un régulateur de débit, puis ces courants sont mélangés dans une ligne d'approvisionnement commune isolée de manière à éviter la condensation des produits vaporisés. Cette ligne rejoint deux autres lignes d'approvisionnement : celle de l'azote de débit principal et celle de SO2 et CO2, ce qui forme la ligne d'approvisionnement principal, qui entre dans la chambre de mélange de la figure 1 par le conduit (2). Il s'agit du gaz de débit principal.In order to be mixed in gaseous form, the liquid hydrocarbons and H 2 O are each vaporized at a temperature of 300 ° C in a stream of nitrogen. The flow rate of each of the currents obtained is controlled by a flow regulator, then these streams are mixed in an isolated common supply line so as to avoid condensation of the vaporized products. This line joins two other supply lines: that of the main flow nitrogen and that of SO 2 and CO 2 , which forms the main supply line, which enters the mixing chamber of Figure 1 by the led (2). This is the main flow gas.

L'oxygène entre dans la chambre de mélange de la figure 1 par le trou (4) du conduit (3) (débit secondaire).The oxygen enters the mixing chamber of Figure 1 through the hole (4) of the conduit (3) (secondary flow).

Les produits gazeux CO, H2, NH3, les hydrocarbures gazeux, l'azote de débit secondaire sont introduits par la même ligne d'approvisionnement dans le conduit (3) à travers quatre des trous (5) du conduit (3) (débit secondaire)The gaseous products CO, H 2 , NH 3 , the gaseous hydrocarbons, the secondary flow nitrogen are introduced through the same supply line into the duct (3) through four of the holes (5) of the duct (3) ( secondary flow)

NO est introduit par les quatre autres trous (5) du conduit (3) (débit secondaire).NO is introduced by the other four holes (5) of the duct (3) (secondary flow).

Les différentes lignes d'approvisionnement en produits à mélanger sont toutes équipées de régulateurs de débits pilotées par des automates. Les automates sont contrôlés par un calculateur programmé pour mettre en oeuvre la composition et les débits du tableau ci-dessus pour reproduire le cycle moteur.The different supply lines for products to be mixed are all equipped with flow controllers controlled by PLCs. The controllers are controlled by a computer programmed to implement the composition and flow rates of the table above to reproduce the engine cycle.

Le contrôle de l'homogénéité du mélange est effectué à l'aide d'une sonde de prélèvement d'analyse placée à la sortie du mélangeur dynamique et analysant à cet endroit la composition du fluide sur toute la longueur du diamètre du mélangeur dynamique. Au cours de la réalisation de ce mélange de composition variable dans le temps, on constate qu'à tout moment le mélange obtenu est homogène, c'est-à-dire que la composition du mélange est identique sur toute la longueur d'un diamètre.The control of the homogeneity of the mixture is carried out using an analysis sampling probe placed at the output of the dynamic mixer and analyzing at this point the composition of the fluid over the entire length of the diameter of the dynamic mixer. During the production of this mixture of variable composition over time, it is found that at any time the mixture obtained is homogeneous, that is to say that the composition of the mixture is identical over the entire length of a diameter. .

Claims (14)

  1. Device for synthesizing gas mixtures, comprising:
    - at least two gas supply lines,
    - at least two flow regulators each collaborating with the gas supply lines,
    - a mixing chamber into which the gas supply lines open, the said mixing chamber comprising:
    • a pipe:
    > connected to the main flow gas supply line in such a way that the gas forms a flow through the pipe,
    > connected to the secondary flow gas supply lines by at least one injector in such a way that the secondary flow gases are introduced into the flow of the main flow gas,
    • a static mixer placed in the continuation of the pipe.
    characterized in that the device comprises at least one controller controlled by a computer for driving the flow regulators, and in that the static mixer is a pipeline made up, in succession:
    - of a first section consisting of a convergent part (6) then a divergent part (7), then
    - of a second section comprising at least two narrowings (8, 9) of the pipeline,
    . each narrowing being obtained by radially crushing the pipeline in one direction, and
    . the said narrowings being offset from one another by an angle of between 10 and 45°, then
    - of a third section consisting of at least one sequence of a convergent part (10) then a divergent part (11) .
  2. Device according to Claim 1, characterized in that the injector is a jet injector having a peripheral swirl effect.
  3. Device according to Claim 2, characterized in that the axis of the injector is at an angle of 90° to the axis of the pipe, has an ejection end coaxial with the pipe and a swirl-inducing component between 15 and 90.
  4. Device according to any one of Claims 1 to 3, characterized in that the first and second sections of the static mixer have a length of the order of one initial diameter, this length corresponding to the part of the pipeline lying between two points where it has a diameter equal to the initial diameter and between which it converges then diverges.
  5. Device according to any one of Claims 1 to 4, characterized in that the two parts, convergent and divergent, of a sequence of a convergent part followed by a divergent part of the pipeline have the same length.
  6. Device according to any one of Claims 1 to 5, characterized in that the minimum diameter of a sequence of a convergent part followed by a divergent part of the pipeline, at the most convergent point of this sequence, is at least one third of the value of the initial diameter.
  7. Device according to any one of the preceding claims, characterized in that the static mixer has no elements forming an intrusion in its wall.
  8. Device according to any one of the preceding claims, characterized in that the mixing chamber is surrounded by an external pipeline having means for injecting a fluid into the gap defined by this exterior pipeline and the external wall of the mixing chamber.
  9. Device according to any one of the preceding claims, characterized in that the gases, the mixing of which carries risks of flammability, are introduced via different supply lines.
  10. Use of the device according to any one of Claims 1 to 9 for testing catalytic compositions.
  11. Use of the device according to any one of Claims 1 to 9 for simulating a motor vehicle engine exhaust gas composition.
  12. Device for testing catalytic compositions employing reactions with gas mixtures, comprising a device for synthesizing a gas mixture in accordance with any one of Claims 1 to 9, the testing device also comprising:
    - an analyser
    - a reaction chamber comprising means for bringing the gas mixture and the catalyst that is to be tested into contact with one another,
    - an analyser for analysing the gas mixture leaving the reaction chamber.
  13. Device according to the preceding claim, characterized in that the analyser for analysing the gas mixture leaving the mixing chamber and the computer controlling the controller which drives the flow regulators are coupled in such a way as to adjust the composition of the gas mixture.
  14. Use of the device according to Claim 12 or 13 for calibrating analysers.
EP02799763A 2002-11-29 2002-11-29 Device for synthesis of gas mixtures and use thereof for testing catalytic compositions Expired - Lifetime EP1581331B1 (en)

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
PCT/FR2002/004113 WO2004050225A1 (en) 2002-11-29 2002-11-29 Device for synthesis of gas mixtures and use thereof for testing catalytic compositions

Publications (2)

Publication Number Publication Date
EP1581331A1 EP1581331A1 (en) 2005-10-05
EP1581331B1 true EP1581331B1 (en) 2007-02-28

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EP02799763A Expired - Lifetime EP1581331B1 (en) 2002-11-29 2002-11-29 Device for synthesis of gas mixtures and use thereof for testing catalytic compositions

Country Status (5)

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EP (1) EP1581331B1 (en)
AT (1) ATE355121T1 (en)
AU (1) AU2002364410A1 (en)
DE (1) DE60218548T2 (en)
WO (1) WO2004050225A1 (en)

Families Citing this family (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
AT521176B1 (en) * 2018-08-28 2019-11-15 Avl List Gmbh Gas mixing device for linearization or calibration of gas analyzers

Family Cites Families (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE3026039A1 (en) * 1980-07-09 1982-01-21 Boris Eskilstuna Lindgren Liquids and/or gases mixed in flow duct - having alternate constrictions and divergence(s) of cross=section
EP0171316B1 (en) * 1984-07-11 1988-10-12 Rhone-Poulenc Chimie Process and apparatus for contacting at least two gaseous components reacting at high temperatures
US4861165A (en) * 1986-08-20 1989-08-29 Beloit Corporation Method of and means for hydrodynamic mixing
US5129412A (en) * 1991-05-08 1992-07-14 Saes Pure Gas, Inc. Aerodynamic blender

Also Published As

Publication number Publication date
WO2004050225A1 (en) 2004-06-17
EP1581331A1 (en) 2005-10-05
ATE355121T1 (en) 2006-03-15
DE60218548D1 (en) 2007-04-12
AU2002364410A1 (en) 2004-06-23
DE60218548T2 (en) 2007-11-08

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