摘要:
The present invention relates to devices for exhaust gas treatment based on metal foams. Using appropriate catalytic coatings, the device may be used as a catalytic converter for diesel and gasoline engines, including oxidation catalysts, 3-way catalysts, de-NOx catalysts, NH3 slip catalysts. The foam structure offers high surface areas and high mixing rates which enhance catalytic performance. The device can be used in parallel for particulate filtration in both diesel and direct injection gasoline engines using deep bed filtration. The present invention employs a multiple-pass radial flow concept, using more than one foam segments (4a, 4b), separated by a diaphragm (5).
摘要:
The present invention relates to devices for exhaust gas treatment based on metal foams. Using appropriate catalytic coatings, the device may be used as a catalytic converter for diesel and gasoline engines, including oxidation catalysts, 3-way catalysts, de-NOx catalysts, NH3 slip catalysts. The foam structure offers high surface areas and high mixing rates which enhance catalytic performance. The device can be used in parallel for particulate filtration in both diesel and direct injection gasoline engines using deep bed filtration. The present invention employs a multiple-pass radial flow concept, using more than one foam segments (4a, 4b), separated by a diaphragm (5).
摘要:
The present invention relates to a device used for the dilution of exhaust gas (diluter) and in particular for engines or vehicules. More particularly, the invention relates to a device and a method which may maintain a constant dilution ratio regardless of the exhaust gas backpressure in the exhaust line, without using any moving parts. The proposed diluter utilizes a very small fraction of the exhaust gas, sampled through a capillary duct, simply immersed to the exhaust flow, which is otherwise freely exhausting to the atmosphere. The sample flowrate through the capillary is achieved by maintaining a regulated underpressure at the capillary outlet. The diluted exhaust is then collected in a stabilization chamber, where temperature, humidity and residence time may be adjusted to condition the collected aerosol at will. Multiple capillaries and stabilization chambers may be cascaded to increase the dilution ratios. After the final dilution stage, particle samples may be collected on a filter for gravimetric determination or analyzed by number counters, surface monitors or any other technique utilized for the physical or chemical characterization of particles. In a preferred embodiment the capillary duct is realized with a hypodermic needle and two cascaded hypodermic needles/stabilization chambers are combined to provide the desired dilution ratio. In another embodiment, exhaust gas may be led to the diluter's capillary duct by means of two probes, located respectively upstream and downstream of any aftertreatment device, which needs to be characterized. By means of shut-off valves, exhaust gas may be fed to the diluter's capillary by either the upstream or the downstream probe, thus providing an estimate of the filtration efficiency of the device.