Patent application number | Description | Published |
20080295499 | Exhaust system utilizing a low-temperature oxidation catalyst - An exhaust treatment system is provided having a first exhaust passageway fluidly connected to an engine. A particulate filter and a selective catalytic reduction catalyst are situated within the first exhaust passageway. In addition, the system has a first oxidation catalyst located within the first exhaust passageway upstream of the particulate filter and the selective catalytic reduction catalyst. The system also has a second exhaust passageway fluidly connected to the first exhaust passageway upstream and downstream of the first oxidation catalyst. The exhaust treatment system further has a sensor configured to sense a parameter indicative of an exhaust gas temperature. Furthermore, the system has a controller configured to direct exhaust gas through the first oxidation catalyst when the exhaust gas temperature is below a threshold temperature and direct the exhaust gas through the second exhaust passageway when the exhaust gas temperature is above the threshold temperature. | 12-04-2008 |
20090031710 | SCR emissions control system - An emissions control system is disclosed. The emissions control system may have an SCR device that receives a flow of exhaust. The emissions control system may also have an injector that introduces a reduction agent into the flow of exhaust at or upstream of a catalyst within the SCR device. The emissions control system may have a controller in communication with the injector, the controller being configured to calculate a first amount of the reduction agent by using an approximation that at least one of a plurality of SCR reactions must be completed before the remaining SCR reactions commence. The controller may also be configured to adjust the injector according to at least the first amount. | 02-05-2009 |
20090049827 | EMISSION CONTROL SYSTEM IMPLEMENTING REDUCTION AGENT INJECTION - An emissions control system is disclosed. The emissions control system may have a power source that creates a flow of exhaust, an SCR catalyst situated to receive the flow of exhaust, and an injector configured to inject a reduction agent into the flow of exhaust in the presence of the SCR catalyst. The emissions control system may further have a controller configured to calculate a spatially dependent surface coverage of the reduction agent on the SCR catalyst and substantially stop injection of the reduction agent when the spatially dependent surface coverage of the reduction agent exceeds a maximum surface coverage of the reduction agent at one or more spatial locations. | 02-26-2009 |
20090049828 | Control of SCR system having a filtering device - An emissions control system is disclosed. The emissions control system may have a power source that creates a flow of exhaust and a filtering device that receives the flow of exhaust. A first sensor may be located at or upstream of the filtering device, the first sensor being configured to measure a first temperature, and an SCR catalyst may be located downstream of the filtering device. The emissions control system may also have an injector configured to inject a reduction agent into the flow of exhaust in the presence of the SCR catalyst. The emissions control system may further have a controller in communication with the first sensor. The controller may be configured to predict a change in an ability of the SCR catalyst to store reduction agent using a measured change in the first temperature and adjust the injector according to the predicted change in the storage ability of the SCR catalyst. | 02-26-2009 |
20090266058 | Exhaust system implementing feedforward and feedback control - An exhaust system for use with a combustion engine is disclosed. The exhaust system may have an exhaust passageway, and a reduction catalyst disposed within the exhaust passageway. The exhaust system may also have a first sensor located to generate a first signal indicative of an operational parameter of the reduction catalyst, and a second sensor located to generate a second signal indicative of a performance parameter of the reduction catalyst. The exhaust system may further have an injection device located to inject reductant upstream of the reduction catalyst, and a controller in communication with the combustion engine, the first sensor, the second sensor, and the injection device. The controller may be configured to determine a NO | 10-29-2009 |
20090266059 | Exhaust system implementing in situ calibration - An exhaust system for use with a combustion engine is disclosed. The exhaust system may have an exhaust passageway, a reduction catalyst, a reductant injector, and a controller. The controller may have a NO | 10-29-2009 |
20090301065 | Exhaust system having exhaust system segment with improved catalyst distribution and method - An exhaust system for an internal combustion engine includes an upstream segment and a downstream segment connecting with the upstream segment. The downstream segment is a NOx reducing segment having an exhaust gas outlet and a reductant inlet disposed between the exhaust gas outlet and an exhaust gas inlet for the downstream segment. The upstream segment further includes a coating having a catalyst configured to increase a ratio of NO | 12-10-2009 |
20100101221 | CATALYSTS, SYSTEMS, AND METHODS FOR REDUCING NOx IN AN EXHAUST GAS - Catalysts, systems, and methods disclosed herein provide for reduced NO | 04-29-2010 |
20100229539 | HYDROCARBON SCR AFTERTREATMENT SYSTEM - An engine exhaust aftertreatment system including a selective catalytic reduction (SCR) device. The system contains no significant amount of catalyzed material upstream of the SCR device. | 09-16-2010 |
20110030343 | SCR REDUCTANT DEPOSIT REMOVAL - An engine exhaust aftertreatment system including a selective catalytic reduction (SCR) system. The SCR system includes a reductant injection system configured to introduce a reductant into a exhaust stream of a engine, a SCR catalysts configured to reduce NOx in the presence of a reductant, and a SCR monitoring system configured to determine temperatures associated with the SCR system. The SCR system also includes a heat source configured to raise the temperature of the exhaust stream and a controller configured to operate the heat source to reach exhaust stream temperatures in the SCR system of at least about 400 degrees Celsius based on the temperature associated with the SCR system. | 02-10-2011 |