EP1461515B1 - Method for regenerating particulate filters by ammonium nitrate injection and device therefor - Google Patents

Method for regenerating particulate filters by ammonium nitrate injection and device therefor Download PDF

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Publication number
EP1461515B1
EP1461515B1 EP02799087A EP02799087A EP1461515B1 EP 1461515 B1 EP1461515 B1 EP 1461515B1 EP 02799087 A EP02799087 A EP 02799087A EP 02799087 A EP02799087 A EP 02799087A EP 1461515 B1 EP1461515 B1 EP 1461515B1
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EP
European Patent Office
Prior art keywords
ammonium nitrate
filtration
temperature
filtration means
injection
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EP02799087A
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German (de)
French (fr)
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EP1461515A1 (en
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Jean-Claude Fayard
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CRMT
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    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F01—MACHINES OR ENGINES IN GENERAL; ENGINE PLANTS IN GENERAL; STEAM ENGINES
    • F01N—GAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR MACHINES OR ENGINES IN GENERAL; GAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR INTERNAL COMBUSTION ENGINES
    • F01N3/00—Exhaust or silencing apparatus having means for purifying, rendering innocuous, or otherwise treating exhaust
    • F01N3/02—Exhaust or silencing apparatus having means for purifying, rendering innocuous, or otherwise treating exhaust for cooling, or for removing solid constituents of, exhaust
    • F01N3/021—Exhaust or silencing apparatus having means for purifying, rendering innocuous, or otherwise treating exhaust for cooling, or for removing solid constituents of, exhaust by means of filters
    • F01N3/023—Exhaust or silencing apparatus having means for purifying, rendering innocuous, or otherwise treating exhaust for cooling, or for removing solid constituents of, exhaust by means of filters using means for regenerating the filters, e.g. by burning trapped particles
    • F01N3/0237—Exhaust or silencing apparatus having means for purifying, rendering innocuous, or otherwise treating exhaust for cooling, or for removing solid constituents of, exhaust by means of filters using means for regenerating the filters, e.g. by burning trapped particles for regenerating ex situ
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F01—MACHINES OR ENGINES IN GENERAL; ENGINE PLANTS IN GENERAL; STEAM ENGINES
    • F01N—GAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR MACHINES OR ENGINES IN GENERAL; GAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR INTERNAL COMBUSTION ENGINES
    • F01N3/00—Exhaust or silencing apparatus having means for purifying, rendering innocuous, or otherwise treating exhaust
    • F01N3/02—Exhaust or silencing apparatus having means for purifying, rendering innocuous, or otherwise treating exhaust for cooling, or for removing solid constituents of, exhaust
    • F01N3/021—Exhaust or silencing apparatus having means for purifying, rendering innocuous, or otherwise treating exhaust for cooling, or for removing solid constituents of, exhaust by means of filters
    • F01N3/023—Exhaust or silencing apparatus having means for purifying, rendering innocuous, or otherwise treating exhaust for cooling, or for removing solid constituents of, exhaust by means of filters using means for regenerating the filters, e.g. by burning trapped particles
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F01—MACHINES OR ENGINES IN GENERAL; ENGINE PLANTS IN GENERAL; STEAM ENGINES
    • F01N—GAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR MACHINES OR ENGINES IN GENERAL; GAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR INTERNAL COMBUSTION ENGINES
    • F01N3/00—Exhaust or silencing apparatus having means for purifying, rendering innocuous, or otherwise treating exhaust
    • F01N3/02—Exhaust or silencing apparatus having means for purifying, rendering innocuous, or otherwise treating exhaust for cooling, or for removing solid constituents of, exhaust
    • F01N3/021—Exhaust or silencing apparatus having means for purifying, rendering innocuous, or otherwise treating exhaust for cooling, or for removing solid constituents of, exhaust by means of filters
    • F01N3/023—Exhaust or silencing apparatus having means for purifying, rendering innocuous, or otherwise treating exhaust for cooling, or for removing solid constituents of, exhaust by means of filters using means for regenerating the filters, e.g. by burning trapped particles
    • F01N3/029—Exhaust or silencing apparatus having means for purifying, rendering innocuous, or otherwise treating exhaust for cooling, or for removing solid constituents of, exhaust by means of filters using means for regenerating the filters, e.g. by burning trapped particles by adding non-fuel substances to exhaust
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F01—MACHINES OR ENGINES IN GENERAL; ENGINE PLANTS IN GENERAL; STEAM ENGINES
    • F01N—GAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR MACHINES OR ENGINES IN GENERAL; GAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR INTERNAL COMBUSTION ENGINES
    • F01N3/00—Exhaust or silencing apparatus having means for purifying, rendering innocuous, or otherwise treating exhaust
    • F01N3/02—Exhaust or silencing apparatus having means for purifying, rendering innocuous, or otherwise treating exhaust for cooling, or for removing solid constituents of, exhaust
    • F01N3/021—Exhaust or silencing apparatus having means for purifying, rendering innocuous, or otherwise treating exhaust for cooling, or for removing solid constituents of, exhaust by means of filters
    • F01N3/023—Exhaust or silencing apparatus having means for purifying, rendering innocuous, or otherwise treating exhaust for cooling, or for removing solid constituents of, exhaust by means of filters using means for regenerating the filters, e.g. by burning trapped particles
    • F01N3/029—Exhaust or silencing apparatus having means for purifying, rendering innocuous, or otherwise treating exhaust for cooling, or for removing solid constituents of, exhaust by means of filters using means for regenerating the filters, e.g. by burning trapped particles by adding non-fuel substances to exhaust
    • F01N3/0293—Exhaust or silencing apparatus having means for purifying, rendering innocuous, or otherwise treating exhaust for cooling, or for removing solid constituents of, exhaust by means of filters using means for regenerating the filters, e.g. by burning trapped particles by adding non-fuel substances to exhaust injecting substances in exhaust stream
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F01—MACHINES OR ENGINES IN GENERAL; ENGINE PLANTS IN GENERAL; STEAM ENGINES
    • F01N—GAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR MACHINES OR ENGINES IN GENERAL; GAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR INTERNAL COMBUSTION ENGINES
    • F01N3/00—Exhaust or silencing apparatus having means for purifying, rendering innocuous, or otherwise treating exhaust
    • F01N3/02—Exhaust or silencing apparatus having means for purifying, rendering innocuous, or otherwise treating exhaust for cooling, or for removing solid constituents of, exhaust
    • F01N3/021—Exhaust or silencing apparatus having means for purifying, rendering innocuous, or otherwise treating exhaust for cooling, or for removing solid constituents of, exhaust by means of filters
    • F01N3/023—Exhaust or silencing apparatus having means for purifying, rendering innocuous, or otherwise treating exhaust for cooling, or for removing solid constituents of, exhaust by means of filters using means for regenerating the filters, e.g. by burning trapped particles
    • F01N3/029—Exhaust or silencing apparatus having means for purifying, rendering innocuous, or otherwise treating exhaust for cooling, or for removing solid constituents of, exhaust by means of filters using means for regenerating the filters, e.g. by burning trapped particles by adding non-fuel substances to exhaust
    • F01N3/0293—Exhaust or silencing apparatus having means for purifying, rendering innocuous, or otherwise treating exhaust for cooling, or for removing solid constituents of, exhaust by means of filters using means for regenerating the filters, e.g. by burning trapped particles by adding non-fuel substances to exhaust injecting substances in exhaust stream
    • F01N3/0296—Exhaust or silencing apparatus having means for purifying, rendering innocuous, or otherwise treating exhaust for cooling, or for removing solid constituents of, exhaust by means of filters using means for regenerating the filters, e.g. by burning trapped particles by adding non-fuel substances to exhaust injecting substances in exhaust stream having means for preheating additional substances

Definitions

  • the present invention relates generally to the field of particulate filters and more particularly to a method of regenerating particulate filters.
  • the present invention relates to a regeneration method of a diesel particulate filter, integrated into the exhaust line of a vehicle, based on the use of an aqueous solution of ammonium nitrate.
  • the present invention also provides a device for carrying out the present method.
  • Document FR-A-2 549 135 describes a process for removing the soot produced by a diesel engine, contained in the exhaust gas and deposited on a filtering means.
  • This process consists mainly of the use of copper chloride to remove carbonaceous particles.
  • This copper chloride is associated with ammonium nitrate, in order to reduce the ignition temperature of the soot particles and to slow down the deposition of copper oxide on the filtration means.
  • Copper chloride and ammonium nitrate, both in powder form, are fed to the filtration means, mixed or separately, distributed in compressed air.
  • CTR Continuous Regenerating Trap
  • This means consists of a catalyst support on which is fixed the catalyst, which is usually a precious metal such as platinum or rhodium.
  • the NO 2 produced by the action of the latter has the property of oxidizing the carbon particles from 250 ° C.
  • the proper functioning of the filter depends on the average temperature reached and the ratio of particles emitted relative to the NO 2 formed.
  • additives are alkalis, alkaline earths or metals which are often used as a mixture.
  • a first disadvantage of these techniques is the prohibitive cost of the additives used.
  • organometallic additives Another disadvantage of these organometallic additives is that they entail an even greater risk of clogging of the filtration means and therefore the resulting reactions, if the temperatures reached in operation are not sufficiently large to burn it.
  • the primary objective of the present invention is therefore to provide a simple, effective and inexpensive method of regeneration of the filtration means contained in the exhaust lines of motor vehicles.
  • Another objective is to provide a regeneration process avoiding any risk of accumulation of particles in the filtration means and therefore any risk of uncontrolled regeneration.
  • Yet another object of the present invention is to provide a method which does not entail significant additional cost for the user.
  • Yet another objective is to provide a method that can be implemented directly on the vehicle, but also by the use of a regeneration device independent of the vehicle.
  • a final objective of the invention is to provide a filtration device for implementing the regeneration method according to the invention.
  • the applicant has had the merit of highlighting that an aqueous solution of pure or quasi-pure ammonium nitrate could be used to regenerate the exhaust gas filtration means.
  • the present invention satisfies the aforementioned objectives by first proposing a method for regenerating a gas filtration device.
  • exhaust systems produced by a motor this process being of the type in which particles, retained on a filter means of said filter device, are burned by the action of a combustion catalyst.
  • This process is characterized in that it consists essentially of using an aqueous solution of ammonium nitrate, to allow an intimate mixture between the nitrate and the carbon particles and cause the combustion of said particles.
  • the process according to the invention comprises a preliminary step, consisting in triggering an injection of ammonium nitrate into the filtration device, when the temperature ⁇ m is less than or equal to ⁇ r , so that the nitrate ammonium, in aqueous form, come impregnate in a particularly homogeneous manner, the particles deposited on the filtration means.
  • the injection of ammonium nitrate is preferentially triggered if P m is greater than or equal to the pressure P r .
  • this alternative method comprises an additional step of carrying out one or more successive injections of the aqueous solution of ammonium nitrate countercurrent in the filtration means maintained at a temperature at least equal to the decomposition temperature of the nitrate ammonium.
  • the aqueous ammonium nitrate solution used has an ammonium nitrate concentration of less than 128 g / 100 ml, and preferably between 10 and 100 g / 100 ml.
  • Another object of the invention relates to a filtration device for implementing the regeneration method according to the invention, which mainly comprises a means for filtering the exhaust gas contained in a reaction chamber, in the flow path of the exhaust gas produced by a motor and a means for injecting the ammonium nitrate solution connected to said reaction chamber.
  • this device also comprises an electronic device controlling the injection means of the solution of the ammonium nitrate solution.
  • the device also comprises at least one temperature probe placed inside the reaction chamber, able to measure the temperature ⁇ m , within it and connected to the electronic control device.
  • it also comprises at least one pressure sensor placed inside said enclosure, able to measure the pressure P m within it and connected to the electronic control device.
  • the injection means of the ammonium nitrate solution mainly comprises a reservoir of said solution, connected to an injection nozzle of said solution inside the reaction chamber, at the level of the filtration means.
  • Said injection nozzle is supplied on the one hand with ammonium nitrate solution by means of a first conduit connecting the reservoir to said nozzle, and on the other hand by compressed air via a second conduit connecting said nozzle to the engine.
  • the conduits connecting the injection nozzle to the tank of the ammonium nitrate solution and to the engine are each equipped with a solenoid valve controlled by the electronic control device.
  • the device also comprises a means for catalyzing the combustion of the particles retained on the filtering means.
  • this catalytic means consists of a support on which is fixed an oxidation catalyst.
  • the filtration means of said device is constituted by at least one set of at least one filter unit.
  • the catalyzing means 20 is preferably a metal support, in the form of a cartridge, on which is fixed a metal catalyst of the oxidation catalyst type, such as platinum.
  • This filtration means 22 consists of a set of filter units. These filter units are preferably of rectangular parallelepiped shape. Their structure is of honeycomb type. They are advantageously made of silicon carbide. However, it is possible to use filter units consisting of other metals or ceramics, such as cordierite. The filter units are separated by a seal, making the latter thermally independent of each other and also allowing their expansion. This seal can occupy only part of the interstitial space of the filter units, thus allowing the circulation of the exhaust gases between them.
  • a temperature probe 24 and a pressure sensor 26 are arranged at the inlet of the chamber 18. These probes have the function of measuring the temperature and the pressure at the inlet of the enclosure. The data relating to these measurements are transmitted to an electronic control device 28 and are analyzed by the latter. This device is also connected to two solenoid valves 30 and 32, arranged respectively on two ducts 34 and 36.
  • the duct 34 has the function of supplying compressed air to an injection nozzle 38 fixed against the wall of the enclosure 18 and a part of which projects inside said enclosure.
  • the conduit 36 connects said injection nozzle 38 to a reservoir 40 containing an aqueous solution of ammonium nitrate.
  • a pump 42 At the outlet of the reservoir 40 is disposed a pump 42, of any suitable design, intended to take the ammonium nitrate into the reservoir and to send it into the conduit 36.
  • the capacity of the tank 40 is chosen according to the type of vehicle on which the device according to the invention is installed. Indeed, it should not be too bulky to be easily installed. However, it should not be too small to avoid too regular refills.
  • the process according to the invention and the device making it possible to implement it are based on the injection of an aqueous solution of ammonium nitrate into the chamber, at the level of the filtration means, in order to optimally burn the carbon particles retained and this during the use of the vehicle.
  • the temperature at the inlet of the chamber 18 is measured, thanks to the probe 24.
  • the measured temperature value ⁇ m is collected by the electronic device 28.
  • the latter will compare this value ⁇ m with a value reference ⁇ r , corresponding to the temperature at which the ammonium nitrate contained in the aqueous solution causes the combustion of these particles.
  • the electronic device triggers the opening of the solenoid valves 30 and 32, in order to supply the injection nozzle 38 in ammonium nitrate solution and pressurized air.
  • the compressed air and the ammonium nitrate solution are mixed in the injection nozzle 38. This mixture is then sprayed on the filtration means 22.
  • the ammonium nitrate solution is sprayed as an aerosol on the filter units. Given the temperature prevailing in the chamber, the ammonium nitrate crystallizes by vaporization of the water used in the solution as a solvent. The ammonium nitrate crystals formed are then dispersed over the entire surface of the filter units, and then melted at a temperature of 173 ° C by optimally impregnating the carbon particles. They decompose suddenly above 210 ° C to cause instantaneous ignition of ammonium nitrate impregnated particles. Finally, the liberated combustion energy propagates the combustion step by step to the neighboring particles.
  • the filtration means is then devoid of deposits and recovers its full filtration capacity.
  • a variant of this method consists in simultaneously measuring the temperature and the pressure at the inlet of the chamber 18, thanks to the temperature probe 24 and to the pressure probe 26.
  • the pressure value P m measured reflects the degree of obstruction of the filtration means 22 by the particles. Indeed, if the filtering means 22 is clogged, the exhaust gas passes more difficultly and then exert a back pressure. Thus, the measurement of the pressure P m corresponds to the best means of controlling the degree of clogging of the filtration means 22.
  • the electronic device 28 compares the measured value P m with a reference value P r , corresponding to the maximum degree of obstruction. If P m is greater than or equal to P r , the electronic device 28 compares ⁇ m to ⁇ r .
  • the device 28 then triggers the diesel injection which leads to the regeneration of the filtration means 22.
  • This operating mode has the advantage of not triggering post-injection when the means of Filtration has reached a certain degree of clogging, which makes it possible to limit the consumption of ammonium nitrate solution.
  • the electronic device 28 can be programmed to trigger an injection of ammonium nitrate solution at a predetermined time interval. For example, such an injection can occur every morning when the vehicle is started.
  • This embodiment is of particular interest insofar as the filtration means being at a temperature more or less equal to the external temperature, the ammonium nitrate solution remains in liquid form. It then uniformly impregnates the carbon particles. Moreover, given the time required for the chamber to reach the temperature ⁇ m , the solution of Ammonium nitrate can permeate the particles deeply. As a result, when the temperature ⁇ m is reached, the combustion of the particles is optimized.
  • the electronic device can be programmed to trigger this cold injection only if a sufficient degree of clogging has been detected at the end of the previous period of use.
  • a filtration means made of a more brittle material than silicon carbide, for example cordierite it may be preferable to program the electronic device so that the regeneration frequency is greater. . Indeed, too much degree of clogging of the filtration means may cause a highly exothermic regeneration, which can damage the filtration means.
  • the ammonium nitrate injection means may be adapted to the device described above. Indeed, a reservoir, equivalent to the reservoir 40 according to the invention, can be advantageously connected to the injector referenced 49 in the single figure of the document FR-A-2 787 343, via a conduit. At the outlet of this reservoir, can be arranged a pump, equivalent to the pump 42 according to the invention.
  • the ammonium nitrate is propagated in the pipe to the filtration device. It then impregnates the particles which are detached from the filtration means under the action of the hot air vein. These particles then join the regenerator by the recirculation means, in which they are burned.
  • a variant of this regeneration process consists of recovering the filtration means after deposition of the vehicle exhaust line and mounting the filtration means directly on the regeneration device.
  • Such a variant has the advantage of not providing an exhaust line having a recirculation circuit of the hot air stream towards the regeneration device after passing through the filtering means.
  • Another interest is related to security. Indeed, the hot air stream reaching relatively high temperatures (of the order of 500 ° C), by radiation, the vehicle is stopped, the entire particle filter can excessively heat the engine parts or surrounding bodywork.
  • the temperature of the filtration means is raised to more than 210 ° C by placing the hot air flow against the current, so as to cause the combustion of all the particles impregnated with ammonium nitrate. It may be advisable to follow particularly the exit temperature of the vein, so as to be able to control the regeneration and, if necessary, be able to slow down the phenomenon by increasing the air flow very significantly.
  • an ultimate evolution of this variant may consist in making final successive injections of aerosol at a temperature of about 200 ° C to finish the regeneration of the filter until no combustion phenomenon.
  • the advantage of the use of the ammonium nitrate solution lies mainly in the fact that it makes it possible to greatly reduce the time required for the regeneration of the filtration means.
  • the aqueous solution of ammonium nitrate used can be made from ammonitrate ammonium nitrate, used as a fertilizer and available at very attractive costs.
  • the ammonium nitrate is freed from the anti-flaking additives it contains such as calcium and magnesium carbonates.
  • the ammonium nitrate is dissolved in a solvent, which is preferably water.
  • ammonium nitrate concentration in the solution is below the saturation threshold of water at 0 ° C, ie less than 128 g / 100 ml. Preferably, this concentration will be less than 100 g / 100 ml.
  • the solution may contain only ammonium nitrate. However, it may be judiciously added soluble salts of alkali, alkaline earth metal, metal in the form of nitrates or acetates or other anions without inconvenience in this aqueous solution.
  • a mixture of iron nitrate, calcium nitrate and cerium nitrate may be conveniently added to the ammonium nitrate solution, each of these constituents having a metal concentration of 1 gram per liter.
  • composition of the solution is chosen so as to have the best reactivity with respect to the oxidation temperature of the carbonaceous materials.
  • Example Use of the method according to the invention on a bus equipped with a 10-liter diesel engine operating in urban use.
  • the reference pressure P r corresponding to the maximum degree of clogging of the filter, at which the regeneration must take place, is set at 200 mbar.
  • an injection of the ammonium nitrate solution has been programmed for 3 minutes corresponding to an injection of 150 cm 3 of the ammonium nitrate solution, which is a quantity sufficient to wet and impregnate all particles trapped on the filter.
  • the temperature rise of the exhaust gas first causes vaporization of the water contained in the solution and crystallization of the ammonium nitrate. This results in a dispersion of the formed ammonium nitrate crystals. The latter then melt at a temperature above 165 ° C and transform into a very fluid liquid that has excellent wettability with the carbon particles retained on the filter. A homogeneous paste of carbon particles and ammonium nitrate is formed.
  • This homogeneous paste ignites itself above 210 ° C, which corresponds to the decomposition temperature of ammonium nitrate, causing the combustion, step by step, of about 90% of the carbon particles. retained on the filter.

Description

La présente invention concerne de façon générale le domaine des filtres à particules et de façon plus particulière, un procédé de régénération de filtres à particules.The present invention relates generally to the field of particulate filters and more particularly to a method of regenerating particulate filters.

Plus particulièrement encore, la présente invention concerne un procédé de régénération d'un filtre à particules pour moteur diesel, intégré dans la ligne d'échappement d'un véhicule, basé sur l'utilisation d'une solution aqueuse de nitrate d'ammonium.More particularly, the present invention relates to a regeneration method of a diesel particulate filter, integrated into the exhaust line of a vehicle, based on the use of an aqueous solution of ammonium nitrate.

En outre, la présente invention vise également un dispositif permettant la mise en oeuvre du présent procédé.In addition, the present invention also provides a device for carrying out the present method.

La réduction, des émissions polluantes liées au fonctionnement des moteurs diesel est l'objectif que tous les constructeurs se sont fixés.The reduction, pollutant emissions related to the operation of diesel engines is the goal that all manufacturers have set.

Différents systèmes ont déjà été développés afin de réduire le niveau de ces émissions polluantes, en particulier en intégrant sur la ligne d'échappement un filtre à particules. Cependant, un enjeu majeur dans le développement de ces techniques consiste dans la mise au point de solutions pour que les particules de carbone piégées sur le filtre, puissent brûler ou s'oxyder au fur et à mesure qu'elles se déposent et ainsi éviter le colmatage de ce dernier.Various systems have already been developed to reduce the level of these pollutant emissions, in particular by integrating on the exhaust line a particulate filter. However, a major challenge in the development of these techniques is the development of solutions so that the carbon particles trapped on the filter, can burn or oxidize as they settle and thus avoid the clogging of the latter.

Les techniques actuellement utilisées faisant intervenir des filtres à particules sont toutes confrontées au problème majeur de la combustion incomplète des particules une fois retenues sur le filtre. En effet, dans les conditions d'utilisation urbaine, la température des gaz d'échappement atteinte n'est pas suffisamment élevée pour provoquer la combustion complète des particules de carbone et par la-même, limiter significativement le colmatage du filtre.Currently used techniques involving particle filters are all confronted with the major problem of incomplete particle combustion once retained on the filter. Indeed, under the conditions of urban use, the temperature of the exhaust gas reached is not high enough to cause the complete combustion of the carbon particles and thereby significantly limit clogging of the filter.

Sans une assistance chimique, les particules charbonneuses issues de la combustion du gazole dans les moteurs diesel ne commencent à s'oxyder significativement qu'au-dessus de 500°C. Or, ces températures n'étant pratiquement jamais atteintes dans les conditions de roulage urbain, il est nécessaire de faire appel à un procédé chimique pour les éliminer.Without chemical assistance, the carbonaceous particles from the combustion of diesel fuel in diesel engines start to oxidize significantly above 500 ° C. However, these temperatures are almost never reached in urban driving conditions, it is necessary to use a chemical process to eliminate them.

Le document FR-A-2 549 135 décrit un procédé pour éliminer la suie produite par un moteur diesel, contenue dans les gaz d'échappement et déposée sur un moyen de filtration. Ce procédé consiste principalement en l'utilisation de chlorure de cuivre pour éliminer les particules charbonneuses. Ce chlorure de cuivre est associé à du nitrate d'ammonium, afin de réduire la température d'allumage des particules de suie et de ralentir le dépôt de d'oxyde de cuivre sur le moyen de filtration. Le chlorure de cuivre et le nitrate d'ammonium, tous les deux sous forme de poudre, sont amenés au niveau du moyen de filtration, en mélange ou séparément, repartis dans l'air comprimé.Document FR-A-2 549 135 describes a process for removing the soot produced by a diesel engine, contained in the exhaust gas and deposited on a filtering means. This process consists mainly of the use of copper chloride to remove carbonaceous particles. This copper chloride is associated with ammonium nitrate, in order to reduce the ignition temperature of the soot particles and to slow down the deposition of copper oxide on the filtration means. Copper chloride and ammonium nitrate, both in powder form, are fed to the filtration means, mixed or separately, distributed in compressed air.

Un tel procédé est aujourd'hui obsolète dans la mesure où l'utilisation du chlorure de cuivre est désormais interdite, de par sa toxicité.Such a process is now obsolete insofar as the use of copper chloride is now prohibited, because of its toxicity.

De plus, l'utilisation de produit solide ne permet pas d'obtenir le mélange homogène nécessaire pour conduire majoritairement à la combustion des matières charbonneuses.Moreover, the use of solid product does not make it possible to obtain the homogeneous mixture necessary to lead predominantly to the combustion of carbonaceous materials.

Pour obtenir l'oxydation de ces particules, d'autres procédés sont actuellement utilisés.To obtain the oxidation of these particles, other processes are currently used.

Ainsi, certains systèmes proposent de disposer en amont du filtre à particules, un moyen de catalyse d'oxydation permettant la transformation du monoxyde d'azote NO, contenu dans les gaz d'échappement, en dioxyde d'azote NO2 à partir de 250 °C. Cette technique, appelée "Continuous Regenerating Trap" (C.R.T.), allie les effets du filtre à particules et du catalyseur d'oxydation du NO.Thus, some systems propose to have, upstream of the particulate filter, a means of oxidation catalysis allowing the conversion of nitric oxide NO, contained in the exhaust gas, into nitrogen dioxide NO 2 from 250 ° C. This technique, called "Continuous Regenerating Trap" (CRT), combines the effects of the particulate filter and the NO oxidation catalyst.

Ce moyen est constitué par un support catalytique sur lequel est fixé le catalyseur, qui est généralement un métal précieux tels que le platine ou le rhodium. Le NO2 produit par l'action de ce dernier possède la propriété d'oxyder les particules de carbone à partir de 250 °C. Toutefois le bon fonctionnement du filtre dépend de la température moyenne atteinte et du rapport de particules émises par rapport au NO2 formé.This means consists of a catalyst support on which is fixed the catalyst, which is usually a precious metal such as platinum or rhodium. The NO 2 produced by the action of the latter has the property of oxidizing the carbon particles from 250 ° C. However, the proper functioning of the filter depends on the average temperature reached and the ratio of particles emitted relative to the NO 2 formed.

Il existe un moyen similaire constituant une variante de ce dernier, dans lequel le catalyseur est fixé directement sur le filtre à particules. Toutefois, seuls certains matériaux constituant le filtre à particules sont aptes à fixer les catalyseurs métalliques. C'est le cas notamment de la cordiérite. Or, des matériaux de ce type sont connus pour être particulièrement sensibles à l'augmentation de température. Il apparaît alors que des augmentations brutales de température qui peuvent se produire dans le filtre à particules lorsqu'il est colmaté, sont susceptibles d'entraîner une détérioration irréversible de ce dernier. Il est alors nécessaire de remplacer le filtre à particules et plus généralement le dispositif d'échappement, ce qui représente un coût tout à fait rédhibitoire.There is a similar means constituting a variant of the latter, in which the catalyst is attached directly to the particulate filter. However, only certain materials constituting the particulate filter are able to fix the metal catalysts. This is particularly the case of cordierite. However, materials of this type are known to be particularly sensitive to the increase in temperature. It then appears that sudden increases in temperature that can occur in the particulate filter when it is clogged, are likely to cause irreversible deterioration of the latter. It is then necessary to replace the particulate filter and more generally the exhaust system, which represents a cost quite unacceptable.

Sur le même principe que la catalyse par métaux précieux, il a été décrit l'utilisation d'additifs organométalliques, introduits dans le gazole, de manière à ce que la particule de carbone formée lors la combustion de carburant soit imprégnée par ce catalyseur.On the same principle as the precious metal catalysis, it has been described the use of organometallic additives, introduced into the gas oil, so that the carbon particle formed during the combustion of fuel is impregnated with this catalyst.

Ces additifs sont des alcalins, des alcalinoterreux ou des métaux qui souvent sont utilisés en mélange.These additives are alkalis, alkaline earths or metals which are often used as a mixture.

Un premier inconvénient de ces techniques est le coût prohibitif des additifs utilisés.A first disadvantage of these techniques is the prohibitive cost of the additives used.

Un autre inconvénient majeur réside dans le fait qu'il est nécessaire de prévoir un dispositif d'additivation complémentaire.Another major disadvantage lies in the fact that it is necessary to provide a complementary additivation device.

Un autre inconvénient de ces additifs organométalliques est qu'ils entraînent un risque encore plus important de colmatage du moyen de filtration et donc aux réactions qui en découlent, si les températures atteintes en fonctionnement ne sont pas suffisamment importantes pour le brûler.Another disadvantage of these organometallic additives is that they entail an even greater risk of clogging of the filtration means and therefore the resulting reactions, if the temperatures reached in operation are not sufficiently large to burn it.

Toutefois, aucun ne donne réellement satisfaction, en égard aux résultats obtenus. De plus, la mise en oeuvre de ces procédés conduit à un surcoût de fonctionnement significatif de par les additifs qu'ils nécessitent ou par la teneur en métaux précieux requise au niveau du support.However, none is really satisfactory in terms of the results obtained. In addition, the implementation of these methods leads to a significant additional cost of operation by the additives they require or by the precious metal content required at the support.

Il s'est également avéré que la mise en oeuvre de ces différents types de procédés en utilisation urbaine sévère, a été à l'origine d'incidents qui ont conduit à la destruction complète des moyens de filtration. L'expertise a montré qu'avant sa destruction, le moyen de filtration s'est progressivement colmaté modifiant ainsi les conditions motrices en augmentant progressivement les températures d'échappement jusqu'à obtenir la bonne température pour enflammer brutalement toutes les particules déposées, l'augmentation brutale de la température entraînant une destruction de celui-ci soit par choc thermique ou tout simplement à cause du niveau excessif de température atteint.It has also been found that the implementation of these different types of processes in severe urban use has led to incidents that led to the complete destruction of the filtration means. Expertise has shown that before its destruction, the filtration medium has gradually become clogged thus changing the driving conditions by gradually increasing the exhaust temperatures until the right temperature to ignite suddenly all the particles deposited, the sudden increase in temperature leading to destruction of it either by thermal shock or simply because of the excessive level of temperature reached.

Dans un tel contexte technique, l'objectif premier de la présente invention est donc de fournir un procédé simple, efficace et peu coûteux de régénération des moyens de filtration contenus dans les lignes d'échappement des véhicules automobiles.In such a technical context, the primary objective of the present invention is therefore to provide a simple, effective and inexpensive method of regeneration of the filtration means contained in the exhaust lines of motor vehicles.

Un autre objectif est de fournir un procédé de régénération évitant tout risque d'accumulation de particules dans le moyen de filtration et donc tout risque de régénération incontrôlée.Another objective is to provide a regeneration process avoiding any risk of accumulation of particles in the filtration means and therefore any risk of uncontrolled regeneration.

Encore un autre objectif de la présente invention est de fournir un procédé n'entraînant pas de surcoût important pour l'utilisateur.Yet another object of the present invention is to provide a method which does not entail significant additional cost for the user.

Encore un autre objectif est de fournir un procédé pouvant être mis en oeuvre directement sur le véhicule, mais également par l'utilisation d'un dispositif de régénération indépendant du véhicule.Yet another objective is to provide a method that can be implemented directly on the vehicle, but also by the use of a regeneration device independent of the vehicle.

Enfin un dernier objectif de l'invention est de fournir un dispositif de filtration permettant de mettre en oeuvre le procédé de régénération selon l'invention.Finally, a final objective of the invention is to provide a filtration device for implementing the regeneration method according to the invention.

Pour atteindre ces objectifs, la demanderesse a eu le mérite de mettre en évidence qu'une solution aqueuse de nitrate d'ammonium pure ou quasi-pure pouvait être utilisée pour régénérer les moyens de filtration de gaz d'échappement.To achieve these objectives, the applicant has had the merit of highlighting that an aqueous solution of pure or quasi-pure ammonium nitrate could be used to regenerate the exhaust gas filtration means.

C'est ainsi que la présente invention satisfait aux susdits objectifs en proposant tout d'abord un procédé de régénération d'un dispositif de filtration des gaz d'échappement produits par un moteur, ce procédé étant du type de ceux dans lesquels des particules, retenues sur un moyen de filtration dudit dispositif de filtration, sont brûlées grâce à l'action d'un catalyseur de combustion. Ce procédé se caractérise en ce qu'il consiste essentiellement à utiliser une solution aqueuse de nitrate d'ammonium, afin de permettre un mélange intime entre le nitrate et les particules de carbone et provoquer la combustion desdites particules.Thus, the present invention satisfies the aforementioned objectives by first proposing a method for regenerating a gas filtration device. exhaust systems produced by a motor, this process being of the type in which particles, retained on a filter means of said filter device, are burned by the action of a combustion catalyst. This process is characterized in that it consists essentially of using an aqueous solution of ammonium nitrate, to allow an intimate mixture between the nitrate and the carbon particles and cause the combustion of said particles.

Selon une variante, le procédé selon l'invention comprend les étapes suivantes :

  • mesurer une température θm dans le dispositif de filtration,
  • comparer θm à une température θr correspondant à la température permettant successivement la vaporisation du solvant et la cristallisation du nitrate d'ammonium,, la fusion des cristaux formés et la combustion des particules de carbone par décomposition du nitrate d'ammonium,
  • si θm est supérieure ou égale à θr, déclencher une injection de la solution aqueuse de nitrate d'ammonium, par l'intermédiaire d'un moyen d'injection approprié, dans le dispositif de filtration, pendant une durée déterminée, afin d'entraîner la combustion complète des particules retenues sur le moyen de filtration.
According to one variant, the method according to the invention comprises the following steps:
  • measure a temperature θ m in the filtration device,
  • comparing θ m with a temperature θ r corresponding to the temperature that successively allows the solvent vaporization and the crystallization of the ammonium nitrate, the melting of the crystals formed and the combustion of the carbon particles by decomposition of the ammonium nitrate,
  • if θ m is greater than or equal to θ r , trigger an injection of the aqueous ammonium nitrate solution, via a suitable injection means, into the filtration device, for a determined period of time, in order to result in complete combustion of the particles retained on the filtering means.

Selon une autre variante, le procédé selon l'invention consiste en outre à :

  • mesurer une pression Pm à l'intérieur du dispositif de filtration, ladite pression Pm reflétant le degré d'obstruction du moyen de filtration par les particules,
  • mesurer la température θm,
  • comparer ladite pression Pm à une pression Pr de référence correspondant au degré d'obstruction maximal acceptable,
  • si Pm est supérieure ou égale à la pression Pr, comparer θm à θr,
  • si θm est supérieure ou égale à θr, déclencher l'injection de la solution aqueuse de nitrate d'ammonium.
According to another variant, the method according to the invention also consists in:
  • measuring a pressure P m inside the filtration device, said pressure P m reflecting the degree of obstruction of the filtration means by the particles,
  • measure the temperature θ m ,
  • comparing said pressure P m with a reference pressure P r corresponding to the maximum acceptable degree of obstruction,
  • if P m is greater than or equal to the pressure P r , compare θ m with θ r ,
  • if θ m is greater than or equal to θ r , trigger the injection of the aqueous ammonium nitrate solution.

De façon avantageuse, le procédé selon l'invention comporte une étape préalable, consistant à déclencher une injection de nitrate d'ammonium dans le dispositif de filtration, lorsque la température θm est inférieure ou égale à θr, de telle sorte que le nitrate d'ammonium, sous forme aqueuse, vienne imprégner de façon particulièrement homogène, les particules déposées sur le moyen de filtration.Advantageously, the process according to the invention comprises a preliminary step, consisting in triggering an injection of ammonium nitrate into the filtration device, when the temperature θ m is less than or equal to θ r , so that the nitrate ammonium, in aqueous form, come impregnate in a particularly homogeneous manner, the particles deposited on the filtration means.

Ainsi, l'injection de nitrate d'ammonium est préférentiellement déclenchée si Pm est supérieure ou égale à la pression Pr.Thus, the injection of ammonium nitrate is preferentially triggered if P m is greater than or equal to the pressure P r .

Une alternative consiste dans un procédé mettant en oeuvre un dispositif de régénération de moyens de filtration ex-situ, consistant à :

  • relier le moyen de filtration audit dispositif de régénération,
  • injecter à contre-courant une solution aqueuse de nitrate d'ammonium dans ledit moyen de filtration, de manière à ce que celui-ci vienne imprégner les particules retenues sur le moyen de filtration, et
  • générer une veine d'air chaud contre-courant dans ledit moyen de filtration de manière à porter la température à l'intérieur dudit moyen de filtration à une température au moins égale à la température de décomposition du nitrate d'ammonium, afin de déclencher la combustion des particules retenues sur le moyen de filtration et le décollement de ces dernières.
An alternative consists in a process using a device for regeneration of ex-situ filtration means , consisting of:
  • connect the filtration means to said regeneration device,
  • countercurrently injecting an aqueous solution of ammonium nitrate into said filtration means, so that it impregnates the particles retained on the filtration means, and
  • generating a flow of hot air against the current in said filtering means so as to raise the temperature inside said filtering means to a temperature at least equal to the decomposition temperature of the ammonium nitrate, in order to trigger the combustion of the particles retained on the filtering means and the detachment of the latter.

Avantageusement, ce procédé alternatif comprend une étape supplémentaire consistant à réaliser une ou plusieurs injections successives de la solution aqueuse de nitrate d'ammonium à contre-courant, dans le moyen de filtration maintenu à une température au moins égale à la température de décomposition du nitrate d'ammonium.Advantageously, this alternative method comprises an additional step of carrying out one or more successive injections of the aqueous solution of ammonium nitrate countercurrent in the filtration means maintained at a temperature at least equal to the decomposition temperature of the nitrate ammonium.

La solution aqueuse de nitrate d'ammonium utilisée présente une concentration en nitrate d'ammonium, inférieure à 128 g/100 ml, et préférentiellement comprise entre 10 et 100 g/100ml.The aqueous ammonium nitrate solution used has an ammonium nitrate concentration of less than 128 g / 100 ml, and preferably between 10 and 100 g / 100 ml.

Elle peut avantageusement comporter également des sels solubles d'alcalins, d'alcalinoterreux, de métaux sous forme de nitrates, d'acétates ou autres anions à des concentrations inférieures à 10 grammes par litre.It may advantageously also comprise soluble salts of alkalis, alkaline earth metals, metals in the form of nitrates, acetates or other anions at concentrations of less than 10 grams per liter.

Un autre objet de l'invention concerne un dispositif de filtration permettant la mise en oeuvre du procédé de régénération selon l'invention, qui comporte principalement un moyen de filtration des gaz d'échappement contenu dans une enceinte réactionnelle, dans la trajectoire du flux des gaz d'échappement produits par un moteur et un moyen d'injection de la solution de nitrate d'ammonium relié à ladite enceinte réactionnelle.Another object of the invention relates to a filtration device for implementing the regeneration method according to the invention, which mainly comprises a means for filtering the exhaust gas contained in a reaction chamber, in the flow path of the exhaust gas produced by a motor and a means for injecting the ammonium nitrate solution connected to said reaction chamber.

De façon avantageuse, ce dispositif comprend également un dispositif électronique commandant le moyen d'injection de la solution de la solution de nitrate d'ammonium.Advantageously, this device also comprises an electronic device controlling the injection means of the solution of the ammonium nitrate solution.

Préférentiellement, le dispositif comporte également au moins une sonde de température placée à l'intérieur de l'enceinte réactionnelle, apte à mesurer la température θm, en son sein et relié au dispositif électronique de commande.Preferably, the device also comprises at least one temperature probe placed inside the reaction chamber, able to measure the temperature θ m , within it and connected to the electronic control device.

Selon une variante remarquable, il comporte également au moins une sonde de pression, placée à l'intérieur de ladite enceinte, apte à mesurer la pression Pm en son sein et relié au dispositif électronique de commande.According to a remarkable variant, it also comprises at least one pressure sensor placed inside said enclosure, able to measure the pressure P m within it and connected to the electronic control device.

Avantageusement, le moyen d'injection de la solution de nitrate d'ammonium comprend principalement un réservoir de ladite solution, relié à une buse d'injection de ladite solution à l'intérieur de l'enceinte réactionnelle, au niveau du moyen de filtration.Advantageously, the injection means of the ammonium nitrate solution mainly comprises a reservoir of said solution, connected to an injection nozzle of said solution inside the reaction chamber, at the level of the filtration means.

Ladite buse d'injection est alimentée d'une part en solution de nitrate d'ammonium par l'intermédiaire d'un premier conduit reliant le réservoir à ladite buse, et d'autre part en air comprimé par l'intermédiaire d'un second conduit reliant la dite buse au moteur.Said injection nozzle is supplied on the one hand with ammonium nitrate solution by means of a first conduit connecting the reservoir to said nozzle, and on the other hand by compressed air via a second conduit connecting said nozzle to the engine.

Selon une autre caractéristique remarquable, les conduits reliant la buse d'injection au réservoir de la solution de nitrate d'ammonium et au moteur sont équipés chacun d'une électrovanne commandée par le dispositif électronique de commande.According to another remarkable characteristic, the conduits connecting the injection nozzle to the tank of the ammonium nitrate solution and to the engine are each equipped with a solenoid valve controlled by the electronic control device.

Selon encore une autre caractéristique remarquable, le dispositif comporte également un moyen de catalyse de la combustion des particules retenues sur le moyen de filtration.According to yet another remarkable characteristic, the device also comprises a means for catalyzing the combustion of the particles retained on the filtering means.

Avantageusement, ce moyen de catalyse est constitué par un support sur lequel est fixé un catalyseur d'oxydation.Advantageously, this catalytic means consists of a support on which is fixed an oxidation catalyst.

De façon préférentielle, le moyen de filtration dudit dispositif est constitué par au moins un ensemble d'au moins une unité filtrante.Preferably, the filtration means of said device is constituted by at least one set of at least one filter unit.

La présente invention sera mieux comprise à la lecture de la description qui suit, faite en référence à la figure unique qui représente, de façon nullement limitative, un exemple de réalisation du dispositif de filtration selon l'invention selon une vue générale schématique, au sein d'un système comprenant un moteur 10 d'un véhicule automobile. Ce moteur 10 est alimenté en combustible à partir d'un réservoir 12, via un conduit d'alimentation 14. Le moteur 10 produit en fonctionnement des gaz d'échappement. Ces gaz sont récupérés par le biais d'un collecteur (non représenté) à la sortie du moteur et sont évacués par l'intermédiaire d'un conduit d'évacuation 16. Ce conduit rejoint une enceinte 18 du dispositif de filtration. Cette enceinte contient un moyen de catalyse 20 et un moyen de filtration 22.The present invention will be better understood on reading the description which follows, made with reference to the single figure which represents, in no way limiting, an embodiment of the filter device according to the invention in a schematic general view, within of a system comprising a motor 10 of a motor vehicle. This engine 10 is supplied with fuel from a tank 12, via a supply duct 14. The engine 10 produces exhaust gases in operation. These gases are recovered via a manifold (not shown) at the engine outlet and are evacuated via an exhaust duct 16. This duct joins an enclosure 18 of the filtration device. This enclosure contains a catalyst means 20 and a filtration means 22.

Le moyen de catalyse 20 est préférentiellement un support métallique, se présentant sous forme d'une cartouche, sur lequel est fixé un catalyseur métallique du type catalyseur d'oxydation, tel que le platine.The catalyzing means 20 is preferably a metal support, in the form of a cartridge, on which is fixed a metal catalyst of the oxidation catalyst type, such as platinum.

Ce moyen de filtration 22 est constitué par un ensemble d'unités filtrantes. Ces unités filtrantes sont préférentiellement de forme parallélépipédique rectangle. Leur structure est de type nid d'abeille. Elles sont avantageusement en carbure de silicium. Toutefois, il est possible d'utiliser des unités filtrantes constituées par d'autres métaux ou des céramiques, tel que la cordiérite. Les unités filtrantes sont séparées par un joint, rendant ces dernières indépendantes thermiquement les unes des autres et permettant également leur dilatation. Ce joint peut n'occuper qu'une partie de l'espace interstitiel des unités filtrantes, permettant ainsi la circulation des gaz d'échappement entre elles.This filtration means 22 consists of a set of filter units. These filter units are preferably of rectangular parallelepiped shape. Their structure is of honeycomb type. They are advantageously made of silicon carbide. However, it is possible to use filter units consisting of other metals or ceramics, such as cordierite. The filter units are separated by a seal, making the latter thermally independent of each other and also allowing their expansion. This seal can occupy only part of the interstitial space of the filter units, thus allowing the circulation of the exhaust gases between them.

A l'entrée de l'enceinte 18, sont disposées une sonde de température 24 et une sonde de pression 26. Ces sondes ont pour fonction de mesurer la température et la pression à l'entrée de l'enceinte. Les données relatives à ces mesures sont transmises à un dispositif électronique de commande 28 et sont analysées par ce dernier. Ce dispositif est également relié à deux électrovannes 30 et 32, disposées respectivement sur deux conduits 34 et 36.At the inlet of the chamber 18, a temperature probe 24 and a pressure sensor 26 are arranged. These probes have the function of measuring the temperature and the pressure at the inlet of the enclosure. The data relating to these measurements are transmitted to an electronic control device 28 and are analyzed by the latter. This device is also connected to two solenoid valves 30 and 32, arranged respectively on two ducts 34 and 36.

Le conduit 34 a pour fonction d'alimenter en air comprimé une buse d'injection 38, fixée contre la paroi de l'enceinte 18 et dont une partie fait saillie à l'intérieur de ladite enceinte.The duct 34 has the function of supplying compressed air to an injection nozzle 38 fixed against the wall of the enclosure 18 and a part of which projects inside said enclosure.

Le conduit 36 relie ladite buse d'injection 38 à un réservoir 40 contenant une solution aqueuse de nitrate d'ammonium. A la sortie du réservoir 40 est disposée une pompe 42, de toute conception convenable, destinée à prélever le nitrate d'ammonium dans le réservoir et de l'envoyer dans le conduit 36.The conduit 36 connects said injection nozzle 38 to a reservoir 40 containing an aqueous solution of ammonium nitrate. At the outlet of the reservoir 40 is disposed a pump 42, of any suitable design, intended to take the ammonium nitrate into the reservoir and to send it into the conduit 36.

La capacité du réservoir 40 est choisie en fonction du type de véhicule sur lequel le dispositif selon l'invention est installé. En effet, il ne doit pas être trop encombrant pour pouvoir être installé facilement. Toutefois, il ne doit pas être trop petit pour éviter des remplissages trop réguliers.The capacity of the tank 40 is chosen according to the type of vehicle on which the device according to the invention is installed. Indeed, it should not be too bulky to be easily installed. However, it should not be too small to avoid too regular refills.

Le procédé selon l'invention et le dispositif permettant de la mettre en oeuvre sont basés sur l'injection d'une solution aqueuse de nitrate d'ammonium dans l'enceinte, au niveau du moyen de filtration, afin de brûler de façon optimale les particules de carbone retenues et ceci au cours de l'utilisation du véhicule.The process according to the invention and the device making it possible to implement it are based on the injection of an aqueous solution of ammonium nitrate into the chamber, at the level of the filtration means, in order to optimally burn the carbon particles retained and this during the use of the vehicle.

Pour ce faire, la température à l'entrée de l'enceinte 18 est mesurée, grâce à la sonde 24. La valeur de température θm mesurée est recueillie par le dispositif électronique 28. Ce dernier va comparer cette valeur θm à une valeur de référence θr, correspondant à la température à laquelle le nitrate d'ammonium contenu dans la solution aqueuse entraîne la combustion de ces particules.To do this, the temperature at the inlet of the chamber 18 is measured, thanks to the probe 24. The measured temperature value θ m is collected by the electronic device 28. The latter will compare this value θ m with a value reference θ r , corresponding to the temperature at which the ammonium nitrate contained in the aqueous solution causes the combustion of these particles.

Si la température θm mesurée est supérieure ou égale à la valeur de référence θr, le dispositif électronique déclenche l'ouverture des électrovannes 30 et 32, afin d'alimenter la buse d'injection 38 en solution de nitrate d'ammonium et en air comprimé. L'air comprimé et la solution de nitrate d'ammonium se mélangent dans la buse d'injection 38. Ce mélange est ensuite pulvérisé sur le moyen de filtration 22.If the measured temperature θ m is greater than or equal to the reference value θ r , the electronic device triggers the opening of the solenoid valves 30 and 32, in order to supply the injection nozzle 38 in ammonium nitrate solution and pressurized air. The compressed air and the ammonium nitrate solution are mixed in the injection nozzle 38. This mixture is then sprayed on the filtration means 22.

Lorsque le volume de solution de nitrate d'ammonium, prédéterminé par le dispositif électronique, a été injecté, l'alimentation est coupée par fermeture de l'électrovanne 32.When the volume of ammonium nitrate solution, predetermined by the electronic device, has been injected, the supply is cut off by closing the solenoid valve 32.

La solution de nitrate d'ammonium est pulvérisée sous forme d'aérosol sur les unités filtrantes. Etant donnée la température régnant dans l'enceinte, le nitrate d'ammonium cristallise par vaporisation de l'eau utilisée dans la solution comme solvant. Les cristaux de nitrate d'ammonium formés viennent ensuite se disperser sur toute la surface des unités filtrantes, puis fondre à une température de 173 °C en imprégnant de façon optimale les particules de carbone. Ils se décomposent brutalement au-dessus de 210°C pour provoquer l'inflammation instantanée des particules imprégnées de nitrate d'ammonium. Enfin, l'énergie de combustion libérée propage la combustion de proche en proche aux particules voisines.The ammonium nitrate solution is sprayed as an aerosol on the filter units. Given the temperature prevailing in the chamber, the ammonium nitrate crystallizes by vaporization of the water used in the solution as a solvent. The ammonium nitrate crystals formed are then dispersed over the entire surface of the filter units, and then melted at a temperature of 173 ° C by optimally impregnating the carbon particles. They decompose suddenly above 210 ° C to cause instantaneous ignition of ammonium nitrate impregnated particles. Finally, the liberated combustion energy propagates the combustion step by step to the neighboring particles.

Le moyen de filtration se retrouve alors dépourvu de dépôts et récupère sa pleine capacité de filtration.The filtration means is then devoid of deposits and recovers its full filtration capacity.

Une variante de ce procédé consiste à mesurer simultanément la température et la pression à l'entrée de l'enceinte 18, grâce à la sonde de température 24 et à la sonde de pression 26. La valeur de pression Pm mesurée reflète le degré d'obstruction du moyen de filtration 22 par les particules. En effet, si le moyen de filtration 22 est colmaté, les gaz d'échappement passent plus difficilement et exercent alors une contre-pression. Ainsi, la mesure de la pression Pm correspond au meilleur moyen de contrôler le degré de colmatage du moyen de filtration 22. Le dispositif électronique 28 compare la valeur Pm mesurée à une valeur de référence Pr, correspondant au degré d'obstruction maximal acceptable du moyen de filtration 22. Si Pm est supérieure ou égale à Pr, le dispositif électronique 28 compare θm à θr. Si θm est supérieure ou égale θr, le dispositif 28 déclenche alors la post-injection de gazole qui conduit à la régénération du moyen de filtration 22. Ce mode opérationnel a pour intérêt de ne déclencher de post-injection que lorsque le moyen de filtration a atteint un degré de colmatage déterminé, ce qui permet de limiter la consommation de solution de nitrate d'ammonium.A variant of this method consists in simultaneously measuring the temperature and the pressure at the inlet of the chamber 18, thanks to the temperature probe 24 and to the pressure probe 26. The pressure value P m measured reflects the degree of obstruction of the filtration means 22 by the particles. Indeed, if the filtering means 22 is clogged, the exhaust gas passes more difficultly and then exert a back pressure. Thus, the measurement of the pressure P m corresponds to the best means of controlling the degree of clogging of the filtration means 22. The electronic device 28 compares the measured value P m with a reference value P r , corresponding to the maximum degree of obstruction. If P m is greater than or equal to P r , the electronic device 28 compares θ m to θ r . If θ m is greater than or equal to θ r , the device 28 then triggers the diesel injection which leads to the regeneration of the filtration means 22. This operating mode has the advantage of not triggering post-injection when the means of Filtration has reached a certain degree of clogging, which makes it possible to limit the consumption of ammonium nitrate solution.

Selon un mode de réalisation particulier, le dispositif électronique 28 peut être programmé afin de déclencher une injection de solution de nitrate d'ammonium à froid à intervalle de temps déterminé. Par exemple, une telle injection peut se produire chaque matin au démarrage du véhicule. Cette réalisation présente un intérêt tout particulier dans la mesure où le moyen de filtration étant à une température plus ou moins égale à la température extérieure, la solution de nitrate de d'ammonium demeure sous forme liquide. Elle imprègne alors de façon uniforme les particules de carbone. De plus, étant donné le temps nécessaire à l'enceinte pour atteindre la température θm, la solution de nitrate d'ammonium peut imprégner les particules en profondeur. De ce fait, lorsque la température θm est atteinte, la combustion des particules s'en trouve optimisée.According to a particular embodiment, the electronic device 28 can be programmed to trigger an injection of ammonium nitrate solution at a predetermined time interval. For example, such an injection can occur every morning when the vehicle is started. This embodiment is of particular interest insofar as the filtration means being at a temperature more or less equal to the external temperature, the ammonium nitrate solution remains in liquid form. It then uniformly impregnates the carbon particles. Moreover, given the time required for the chamber to reach the temperature θ m , the solution of Ammonium nitrate can permeate the particles deeply. As a result, when the temperature θ m is reached, the combustion of the particles is optimized.

De façon avantageuse, le dispositif électronique peut être programmé pour ne déclencher cette injection à froid qu'à la condition qu'un degré de colmatage suffisant ait été détecté, à la fin de la précédente période d'utilisation.Advantageously, the electronic device can be programmed to trigger this cold injection only if a sufficient degree of clogging has been detected at the end of the previous period of use.

Dans le cas de l'utilisation d'un moyen de filtration confectionné dans un matériau plus fragile que le carbure de silicium, par exemple la cordiérite, Il peut être préférable de programmer le dispositif électronique de telle sorte que la fréquence de régénération soit plus grande. En effet, un degré de colmatage trop important du moyen de filtration risque de provoquer une régénération fortement exothermique, qui peut endommager le moyen de filtration.In the case of the use of a filtration means made of a more brittle material than silicon carbide, for example cordierite, it may be preferable to program the electronic device so that the regeneration frequency is greater. . Indeed, too much degree of clogging of the filtration means may cause a highly exothermic regeneration, which can damage the filtration means.

Un procédé de régénération alternatif à celui décrit ci-dessus consiste, de façon générale, à utiliser un dispositif de régénération de moyen de filtration ex-situ. De façon plus particulière, ce procédé alternatif consiste à :

  • relier le moyen de filtration au dispositif de régénération,
  • injecter à contre-courant la solution aqueuse de nitrate d'ammonium dans le moyen de filtration, de manière à ce que celui-ci vienne imprégner les particules retenues sur le moyen de filtration, et
  • générer une veine d'air chaud contre-courant dans ledit moyen de filtration de manière à porter la température à l'intérieur du moyen de filtration à une température au moins égale à la température de décomposition du nitrate d'ammonium, afin de déclencher la combustion des particules retenues sur le moyen de filtration et le décollement de ces dernières.
An alternative regeneration method to that described above consists, in general, in using a device for regeneration of ex-situ filtration means . More particularly, this alternative method consists of:
  • connect the filtration means to the regeneration device,
  • countercurrently injecting the aqueous ammonium nitrate solution into the filtration means, so that the latter comes to impregnate the particles retained on the filtration means, and
  • generating a stream of hot air against the current in said filtration means so as to bring the temperature inside the filtration means to a temperature at least equal to the decomposition temperature of the ammonium nitrate, in order to trigger the combustion of the particles retained on the filtering means and the detachment of the latter.

Un tel dispositif de régénération est décrit dans le document FR-A-2 787 343.Such a regeneration device is described in document FR-A-2 787 343.

En référence à la figure unique de ce document, ce dispositif comprend essentiellement :

  • des moyens de fourniture d'une veine d'air chaud (27, 26, 22) raccordés à la ligne d'échappement afin de faire circuler la veine d'air à contre-courant à l'amener à traverser le filtre,
  • des moyens (29) de recirculation de la veine d'air chaud,
  • et un régénérateur (35) apte à provoquer la combustion des particules en suspension dans la veine et à filtrer cette dernière et qui est interposé entre les moyens de fourniture de la veine et ceux assurant sa recirculation.
Referring to the single figure of this document, this device essentially comprises:
  • means for supplying a stream of hot air (27, 26, 22) connected to the exhaust line in order to circulate the airstream against the current to cause it to pass through the filter,
  • means (29) for recirculating the hot air vein,
  • and a regenerator (35) capable of causing the combustion of particles suspended in the vein and of filtering the latter and which is interposed between the means for supplying the vein and those ensuring its recirculation.

Le moyen d'injection du nitrate d'ammonium peut être adapté sur le dispositif décrit ci-dessus. En effet, un réservoir, équivalent au réservoir 40 selon l'invention, peut être avantageusement relié à l'injecteur référencé 49 sur la figure unique du document FR-A-2 787 343, par l'intermédiaire d'un conduit. A la sortie de ce réservoir, peut être disposée une pompe, équivalente à la pompe 42 selon l'invention. Le nitrate d'ammonium se propage dans la canalisation jusqu'au dispositif de filtration. Il vient alors imprégner les particules qui se détachent du moyen de filtration sous l'action de la veine d'air chaud. Ces particules rejoignent alors le régénérateur par les moyens de recirculation, dans lequel elles sont brûlées.The ammonium nitrate injection means may be adapted to the device described above. Indeed, a reservoir, equivalent to the reservoir 40 according to the invention, can be advantageously connected to the injector referenced 49 in the single figure of the document FR-A-2 787 343, via a conduit. At the outlet of this reservoir, can be arranged a pump, equivalent to the pump 42 according to the invention. The ammonium nitrate is propagated in the pipe to the filtration device. It then impregnates the particles which are detached from the filtration means under the action of the hot air vein. These particles then join the regenerator by the recirculation means, in which they are burned.

Une variante de ce procédé de régénération consiste à récupérer le moyen de filtration après dépôt de la ligne d'échappement du véhicule et à monter le moyen de filtration directement sur le dispositif de régénération. Une telle variante présente comme intérêt de ne pas prévoir une ligne d'échappement présentant un circuit de recirculation de la veine d'air chaud en direction du dispositif de régénération, après passage dans le moyen de filtration. Un autre intérêt est lié à la sécurité. En effet, la veine d'air chaud atteignant des températures relativement importantes (de l'ordre de 500°C), par rayonnement, le véhicule étant à l'arrêt, l'ensemble du filtre à particules peut chauffer exagérément les pièces moteurs ou carrosserie environnantes.A variant of this regeneration process consists of recovering the filtration means after deposition of the vehicle exhaust line and mounting the filtration means directly on the regeneration device. Such a variant has the advantage of not providing an exhaust line having a recirculation circuit of the hot air stream towards the regeneration device after passing through the filtering means. Another interest is related to security. Indeed, the hot air stream reaching relatively high temperatures (of the order of 500 ° C), by radiation, the vehicle is stopped, the entire particle filter can excessively heat the engine parts or surrounding bodywork.

Une fois le filtre monté sur la machine, la température du moyen de filtration est portée à plus de 210 °C par mise en place de la veine d'air chaud à contre courant, de manière à provoquer la combustion de toutes les particules imprégnées de nitrate d'ammonium. Il peut être judicieux de suivre particulièrement la température de sortie de la veine, de manière à pouvoir contrôler la régénération et, le cas échéant, pouvoir ralentir le phénomène en augmentant de façon très importante le débit d'air.Once the filter mounted on the machine, the temperature of the filtration means is raised to more than 210 ° C by placing the hot air flow against the current, so as to cause the combustion of all the particles impregnated with ammonium nitrate. It may be advisable to follow particularly the exit temperature of the vein, so as to be able to control the regeneration and, if necessary, be able to slow down the phenomenon by increasing the air flow very significantly.

Selon cette dernière variante, il peut être judicieusement prévu une étape préalable d'injection de la solution de nitrate d'ammonium dans le moyen de filtration, avant que celui ne soit monté sur le dispositif de régénération. Une telle étape permet une meilleure imprégnation des particules de carbone par la solution aqueuse de nitrate d'ammonium et donc une meilleure combustion de ces dernières, une fois retenues sur le régénérateur.According to this last variant, it may be judiciously provided a prior step of injection of the ammonium nitrate solution in the filtering means, before that is mounted on the regeneration device. Such a step allows better impregnation of the carbon particles with the aqueous solution of ammonium nitrate and therefore better combustion of the latter, once retained on the regenerator.

Enfin, une ultime évolution de cette variante peut consister à procéder à des ultimes injections successives d'aérosol à une température voisine de 200°C pour finir la régénération du filtre jusqu'à absence de phénomène de combustion.Finally, an ultimate evolution of this variant may consist in making final successive injections of aerosol at a temperature of about 200 ° C to finish the regeneration of the filter until no combustion phenomenon.

Dans le cas de la régénération ex-situ, l'intérêt de l'utilisation de la solution de nitrate d'ammonium réside principalement dans le fait qu'elle permet de réduire fortement le temps nécessaire à la régénération du moyen de filtration.In the case of ex-situ regeneration , the advantage of the use of the ammonium nitrate solution lies mainly in the fact that it makes it possible to greatly reduce the time required for the regeneration of the filtration means.

La solution aqueuse de nitrate d'ammonium utilisée peut être confectionnée à partir de nitrate d'ammonium de qualité ammonitrate, utilisé comme engrais et disponible à des coûts très intéressants.The aqueous solution of ammonium nitrate used can be made from ammonitrate ammonium nitrate, used as a fertilizer and available at very attractive costs.

Par filtration ou séparation centrifuge, le nitrate d'ammonium est débarrassé des additifs anti-floconnage qu'il contient tel que les carbonates de calcium et de magnésium.By filtration or centrifugal separation, the ammonium nitrate is freed from the anti-flaking additives it contains such as calcium and magnesium carbonates.

Le nitrate d'ammonium est dissous dans un solvant, qui est préférentiellement de l'eau.The ammonium nitrate is dissolved in a solvent, which is preferably water.

Il est préférable que la concentration en nitrate d'ammonium dans la solution soit inférieure au seuil de saturation de l'eau à 0 °C, soit inférieure à 128 g/100 ml. Préférentiellement, cette concentration sera inférieure à 100 g/100 ml.It is preferable that the ammonium nitrate concentration in the solution is below the saturation threshold of water at 0 ° C, ie less than 128 g / 100 ml. Preferably, this concentration will be less than 100 g / 100 ml.

La solution peut ne contenir que du nitrate d'ammonium. Toutefois, il peut être judicieusement rajouté des sels solubles d'alcalins, d'alcalinoterreux, de métaux sous forme de nitrates ou d'acétates ou autres anions sans inconvénient dans cette solution aqueuse.The solution may contain only ammonium nitrate. However, it may be judiciously added soluble salts of alkali, alkaline earth metal, metal in the form of nitrates or acetates or other anions without inconvenience in this aqueous solution.

Par exemple un mélange de nitrate de fer, nitrate de calcium et de nitrate de cérium pourra judicieusement être ajouté à la solution de nitrate d'ammonium, chacun de ces constituants ayant une concentration en métal de 1 gramme par litre.For example a mixture of iron nitrate, calcium nitrate and cerium nitrate may be conveniently added to the ammonium nitrate solution, each of these constituents having a metal concentration of 1 gram per liter.

Ces sels sont ajoutés en quantités très réduites de manière à ce que leur concentration total dans la solution de nitrate d'ammoniaque reste inférieure à 10 grammes/ litre.These salts are added in very small amounts so that their total concentration in the ammonium nitrate solution remains below 10 grams / liter.

La composition de la solution est choisie de façon à présenter la meilleure réactivité vis à vis de la température d'oxydation des matières charbonneuses.The composition of the solution is chosen so as to have the best reactivity with respect to the oxidation temperature of the carbonaceous materials.

Exemple : Utilisation du procédé selon l'invention sur un bus équipé d'un moteur diesel de 10 litres de cylindré fonctionnant en utilisation urbaine. Example: Use of the method according to the invention on a bus equipped with a 10-liter diesel engine operating in urban use.

La pression de référence Pr, correspondant au degré maximal de colmatage du filtre, auquel la régénération doit s'effectuer, est fixée à 200 mbars.The reference pressure P r , corresponding to the maximum degree of clogging of the filter, at which the regeneration must take place, is set at 200 mbar.

Pendant la phase démarrage, dès la mise en marche du moteur, une injection de la solution de nitrate d'ammonium a été programmée durant 3 minutes correspondant à une injection de 150 cm3 de la solution de nitrate d'ammonium, qui est une quantité suffisante pour mouiller et imprégner toutes les particules piégées sur le filtre.During the start-up phase, as soon as the engine is started, an injection of the ammonium nitrate solution has been programmed for 3 minutes corresponding to an injection of 150 cm 3 of the ammonium nitrate solution, which is a quantity sufficient to wet and impregnate all particles trapped on the filter.

La monté en température des gaz d'échappement entraîne d'abord la vaporisation de l'eau contenue dans la solution et une cristallisation du nitrate d'ammonium. Il s'ensuit une dispersion des cristaux de nitrate d'ammonium formés. Ces derniers entrent ensuite en fusion à une température supérieure à 165 °C et se transforment en un liquide très fluide qui présente une excellente mouillabilité avec les particules de carbone retenues sur le filtre. Il se forme alors une pâte homogène de particules de carbone et de nitrate d'ammonium.The temperature rise of the exhaust gas first causes vaporization of the water contained in the solution and crystallization of the ammonium nitrate. This results in a dispersion of the formed ammonium nitrate crystals. The latter then melt at a temperature above 165 ° C and transform into a very fluid liquid that has excellent wettability with the carbon particles retained on the filter. A homogeneous paste of carbon particles and ammonium nitrate is formed.

Cette pâte homogène s'enflamme d'elle-même au-dessus de 210 °C, qui correspond à la température de décomposition du nitrate d'ammonium, provoquant la combustion, de proche en proche, d'environ 90 % des particules de carbone retenues sur le filtre.This homogeneous paste ignites itself above 210 ° C, which corresponds to the decomposition temperature of ammonium nitrate, causing the combustion, step by step, of about 90% of the carbon particles. retained on the filter.

Claims (19)

  1. A process for regenerating a device for filtering exhaust gases produced by an engine (10), this process being of the type in which particles, retained on a filtration means (22) of said filtration device, are burned through the action of a combustion catalyst, characterised in that it consists essentially in using an aqueous solution of ammonium nitrate in order to bring about combustion of said particles.
  2. A process according to the preceding claim, characterised in that it comprises the following steps:
    - measuring a temperature θm in the filtration device,
    - comparing θm with a temperature θr corresponding to the temperature successively allowing vaporisation of the solvent and crystallisation of the ammonium nitrate, fusion of the crystals formed and combustion of the carbon particles by decomposition of the ammonium nitrate,
    - if θm is greater than or equal to θr, triggering injection of the aqueous ammonium nitrate solution, through the intermediary of a suitable injection means, into the filtration device, for a predetermined period, in order to bring about complete combustion of the particles retained on the filtration means (22).
  3. A process according to claim 1, characterised in that it also consists in:
    - measuring a pressure Pm inside the filtration device, said pressure Pm reflecting the degree of obstruction of the filtration means (22) by the particles,
    - measuring the temperature θm,
    - comparing said pressure Pm with a reference pressure Pr corresponding to the maximum acceptable degree of obstruction,
    - if Pm is greater than or equal to the pressure Pr, comparing θm with θr,
    - if θm is greater than or equal to θr, triggering injection of the aqueous ammonium nitrate solution.
  4. A process according to either one of claims 2 or 3, characterised in that it comprises a prior step, consisting in triggering an injection of ammonium nitrate into the filtration device when the temperature θm is lower than or equal to θr, in such a way that the ammonium nitrate, in aqueous form, homogeneously impregnates the particles deposited on the filtration means.
  5. A process according to claim 4, characterised in that said injection of ammonium nitrate is triggered if Pm is greater than or equal to the pressure Pr.
  6. A process according to claim 1, characterised in that it consists in implementing a device for regenerating filtration means ex situ, and comprises the following steps:
    - connecting the filtration means (22) to a device for regenerating such means,
    - counter-currently injecting an aqueous solution of ammonium nitrate into said filtration means (22), in such a way that it impregnates the particles retained on the filtration means (22), and
    - generating a counter-current stream of hot air in said filtration means (22) in such a way as to bring the temperature inside said filtration means to a temperature at least equal to the decomposition temperature of the ammonium nitrate, in order to trigger combustion of the particles retained on the filtration means and detachment thereof.
  7. A process according to claim 6, characterised in that it comprises an additional step consisting in performing one or more successive counter-current injections of the aqueous ammonium nitrate solution into the filtration means (22) held at a temperature at least equal to the decomposition temperature of the ammonium nitrate.
  8. A process according to any one of claims 1 to 7, characterised in that the aqueous ammonium nitrate solution exhibits a concentration of ammonium nitrate of less than 128 g/100 ml, and preferably between 10 and 100 g/100 ml.
  9. A process according to claim 8, characterised in that the aqueous ammonium nitrate solution also comprises soluble alkali metal salts, alkaline earth metal salts, salts of metals in the form of nitrates, acetates or other anions in concentrations lower than 10 grams per litre.
  10. A filtration device allowing implementation of the regeneration process according to any one of claims 1 to 5, characterised in that it principally comprises a filtration means (22) for exhaust gases, contained in a reaction chamber (18) in the flow trajectory of the exhaust gases produced by an engine (10), and an injection means for the ammonium nitrate solution connected to said reaction chamber (18).
  11. A device according to claim 10, characterised in that it also comprises an electronic device (18) controlling the injection means for the ammonium nitrate solution.
  12. A device according to claim 10 or claim 11, characterised in that it also comprises at least one temperature probe (24) placed inside the reaction chamber (18), capable of measuring the temperature θm within it and connected to the electronic control device (28).
  13. A device according to any one of claims 10 to 12, characterised in that it also comprises at least one pressure probe (26) placed inside said chamber (18), capable of measuring the pressure Pm within it and connected to the electronic control device (28).
  14. A device according to any one of claims 10 to 13, characterised in that the injection means for the ammonium nitrate solution principally comprises a reservoir of said solution (40) connected to an injection nozzle (30) for said solution, inside the reaction chamber (18) at the level of the filtration means (22).
  15. A filtration device according to claim 14, characterised in that said injection nozzle (38) is supplied on the one hand with ammonium nitrate solution through the intermediary of a first duct (36) connecting the reservoir (40) to said nozzle (38), and on the other hand with compressed air through the intermediary of a second duct (34) connecting said nozzle (38) to the engine (10).
  16. A device according to either one of claims 14 or 15, characterised in that the ducts (36, 34) connecting the injection nozzle (38) respectively to the ammonium nitrate solution reservoir (40) and to the engine (10) are each equipped with a solenoid valve (32, 30) controlled by the electronic control device (28).
  17. A device according to any one of claims 10 to 16, characterised in that it also comprises a means (20) for catalysing combustion of the particles retained on the filtration means.
  18. A device according to claim 17, characterised in that the catalysis means (20) consists of a support on which an oxidation catalyst is immobilised.
  19. A device according to any one of claims 10 to 18, characterised in that the filtration means (22) consists of at least one assembly of at least one filtering unit.
EP02799087A 2001-12-03 2002-12-03 Method for regenerating particulate filters by ammonium nitrate injection and device therefor Expired - Lifetime EP1461515B1 (en)

Applications Claiming Priority (3)

Application Number Priority Date Filing Date Title
FR0115598 2001-12-03
FR0115598A FR2833036B1 (en) 2001-12-03 2001-12-03 PROCESS FOR REGENERATING PARTICLE FILTERS BY INJECTION OF AMMONIUM NITRATE AND DEVICE FOR IMPLEMENTING SAME
PCT/FR2002/004145 WO2003048534A1 (en) 2001-12-03 2002-12-03 Method for regenerating particulate filters by ammonium nitrate injection and device therefor

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EP1461515A1 EP1461515A1 (en) 2004-09-29
EP1461515B1 true EP1461515B1 (en) 2006-09-27

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AU (1) AU2002364313A1 (en)
DE (1) DE60215052T2 (en)
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WO (1) WO2003048534A1 (en)

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FR2873157B1 (en) * 2004-07-13 2008-04-25 Faurecia Sys Echappement METHOD AND DEVICE FOR REGENERATING A PARTICLE FILTER OF AN EXHAUST LINE OF A DIESEL ENGINE

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* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CA990073A (en) * 1973-03-27 1976-06-01 Polar Chemicals Limited Method for the removal of soot and like deposits
DE3325391A1 (en) 1983-07-14 1985-01-24 Filterwerk Mann & Hummel Gmbh, 7140 Ludwigsburg METHOD FOR REMOVING SOOT FROM THE EXHAUST GASES OF AN INTERNAL COMBUSTION ENGINE
FR2787343A1 (en) 1998-12-18 2000-06-23 Finecor Regenerating particle filter from exhaust pipe of diesel engine

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DE60215052T2 (en) 2007-04-19
DE60215052D1 (en) 2006-11-09
FR2833036A1 (en) 2003-06-06
EP1461515A1 (en) 2004-09-29
FR2833036B1 (en) 2004-02-13
AU2002364313A1 (en) 2003-06-17
WO2003048534A1 (en) 2003-06-12

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