Unit monitoring electrically-conductive particles in gas flow, e.g. soot in diesel exhaust, includes measurement system for electrical resistance of deposited particles

• Main Authors: PRUVOST GUILLAUME, DEMENTHON JEAN BAPTISTE, BOUCHEZ MATTHIAS, PAJOT OLIVIER
• Format: Patent
• Language: English; French
• Published: 24.08.2001
• Edition: 7
• Subjects: BLASTING; CLIMATE CHANGE MITIGATION TECHNOLOGIES RELATED TOTRANSPORTATION; ENGINE PLANTS IN GENERAL; GAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR INTERNALCOMBUSTION ENGINES; GAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR MACHINES ORENGINES IN GENERAL; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; HEATING; INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIRCHEMICAL OR PHYSICAL PROPERTIES; LIGHTING; MACHINES OR ENGINES IN GENERAL; MEASURING; MECHANICAL ENGINEERING; PHYSICS; STEAM ENGINES; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS; TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINSTCLIMATE CHANGE; TESTING; WEAPONS

The sensor (S) in the gas flow, captures particles. Its long dielectric (1) spaces terminal electrodes (2) apart. An instrument (3) measures electrical resistance variation arising from the deposits. A processor (4) determines particle flow rate, as a function of variations in electrical resistance measured. A more specific unit is claimed, for evaluating the degree of filter blocking by conductive particles, e.g. soot, based on the same principles. The sensor surface has discontinuities, to augment particle fixation capacity. These include grooves, flat areas or porosity. A computer (4) processes the results, connected to an instrument (3) measuring variations in electrical resistance. A heater (5) is controlled by the computer, to remove accumulated particles by combustion, once the sensor resistance descends below a given threshold. The heater comprises electrical resistances included in the sensor. The computer measures frequency of sensor burn-off. The sensor is implanted at the upstream end of the filter, to track its degree of blockage (by inference). A second is implanted downstream, relative to the flow, to detect possible filter failure. The calculator compares burn-off frequency against a reference value. Filter regeneration is initiated by the computer, as a function of variations of resistance measured by the sensor. The filter is located in the exhaust flow of a heat engine or internal combustion engine. The computer (4) controls filter regeneration in accordance with measured sensor resistance, by modification of engine operational conditions. - Dispositif pour contrôler le débit de particules présentant une certaine conductivité électrique transportées par un flux de gaz, par mesure de la variation de la conductivité électrique entre des électrodes, affectée par le dépôt de ces particules entre elles.- Il comporte une sonde (S) rapportée localement en un point de l'élément filtrant (6) et interposée dans le flux gazeux, comprenant un barreau ou tube (1) en un matériau diélectrique associé à des électrodes (2) espacées l'une de l'autre, un moyen (3) de mesure de la variation de la résistance électrique résultant du dépôt des particules sur le barreau et des moyens de calcul (4) pour contrôler le degré d'encrassement de l'élément filtrant en fonction de la résistance électrique mesurée, adaptés à commander l'épuration de la sonde (S) et, pour certaines applications, de l'élément filtrant (6) lui-même.- Applications dans l'industrie automobile par exemple, pour contrôler l'accumulation dans un pot d'échappement, de particules carbonées ou suies évacuées dans les gaz de combustion d'un moteur thermique, par exemple.