Abstract: A method for regenerating a particulate filter may comprise calculating a soot layer state correction factor based on a rate of regeneration and a rate of particulate loading in the particulate filter and calculating an estimated soot load in the particulate filter based on a pressure drop of an exhaust gas flowing through the particulate filter and the calculated soot layer state correction factor. The method for regenerating the particulate filter may further comprise causing regeneration of the particulate filter when the estimated soot load is greater than or equal to a threshold value.

Abstract: A method for regenerating a diesel particulate filter includes elevating a temperature of a gas stream flowing into an inlet of the diesel particulate filter to greater than or equal to 450° of the inlet of the diesel particulate filter, wherein the gas stream at the inlet of the diesel particulate filter contains an amount of NOx of equal to or greater than 300 ppm, and an amount of O2 of equal to or greater than 5% volume, thereby burning the soot within the diesel particulate filter. The method also includes elevating a temperature of the gas stream flowing into the inlet of the diesel particulate filter to less than or equal to 550° C. at the inlet of the diesel particulate filter, wherein a burn rate of soot from porous watts of the diesel particulate filter is greater than or equal to 3.8 grams/liter/hour.

Abstract: A partial wall-flow filter having some unplugged flow-through channels and some plugged channels. Desirable combinations of filtration efficiency and back pressure may be provided by combinations of t wall?305 urn, MPD?20 ?m, % P?50%, and CD?250 cpsi wherein t wall is the transverse thickness of the porous walls, MPD is a mean pore diameter of the porous walls, % P is the total porosity of the porous walls, and CD is the cell density of the channels. In one embodiment, some of the plugged channels are located adjacent to the inlet end and some are located adjacent to the outlet end. Systems and method including the partial wall-flow filter are also described.

Abstract: Mass based methods and systems for estimating soot load in a filter of an after-treatment system for exhaust stream are provided. The after-treatment system can comprise a sensor, a filter, and a processor configured to estimate soot load in the filter based on a mass based multi-layer model. An example system includes a virtual sensor comprising an estimator for providing information corresponding to a filter outlet NO2 concentration. An example method includes the steps of providing the mass based multi-layer model, passing the exhaust stream through the filter, and using the sensor to monitor a condition of the exhaust stream. The example method further includes the steps of calculating a total regeneration rate based on the multi-layer model by solving a second-order ordinary differential equation with a plurality of parameters using an analytical approach, and estimating the soot load based on the calculated total regeneration rate.

Abstract: A particulate filter may comprise an inlet end, an outlet end, and a plurality of parallel channels disposed and configured to flow fluid from the inlet end to the outlet end, the channels being defined by a plurality of porous walls configured to trap particulate matter. The particulate filter may define at least one filtration region including a first group of channels and at least one bypass region including a second group of channels, wherein at least some of the channels in the first group of channels are plugged at an end thereof, wherein the channels in the second group of channels are unplugged, and wherein greater than or equal to about 70% of the plurality of parallel channels are plugged at an end thereof.

Abstract: Disclosed are ceramic honeycomb articles which possess a unique microstructure characterized by porosity between 40% and 70%, and the presence of coarse pores exhibiting a depth equivalent to the thickness of the cell wall and a dimensional width, in the plane of the cell wall, exhibiting a diameter that is at least as large as the thickness of the cell wall. The articles exhibits reduced filtration efficiency coupled with low pressure drop across the filter, and a reduced regeneration need. Such ceramic articles are particularly well suited for filtration applications, such as off-road and retro-fit diesel exhaust filters or DPFs. Also disclosed is a method for manufacturing the ceramic article wherein the pore former is capable of forming coarse pores.

Abstract: Systems and methods for controlling temperature and total hydrocarbon slip in an exhaust system are provided. Control systems can comprise an oxidation catalyst, a particulate filter, a fuel injector, and a processor for controlling a fuel injection based on an oxidation catalyst model. Example system includes a virtual sensor comprising a controller for calculating and providing the total hydrocarbon slip to subsystems for after-treatment management based on modeling the oxidation catalyst. Example methods for controlling the temperature and the total hydrocarbon slip in an exhaust system include the steps of providing an oxidation catalyst model, monitoring a condition of the exhaust system, calculating a hydrocarbon fuel injection flow rate and controlling a fuel injection. The example methods further include the steps of determining an error in the oxidation catalyst model based on the monitored condition and changing the oxidation catalyst model to reduce the error.

Abstract: Porous ceramic diesel particulate filters are regenerated to combust accumulated carbon particulates trapped therein through a controlled regeneration process wherein heat is input to the filter at a ramped or staged heating rate below that rate at which the particulate combustion process would proceed so rapidly and extensively that filter temperatures would be raised to filter-damaging levels.

Abstract: A particulate filter may comprise an inlet end, an outlet end, and a plurality of channels disposed and configured to flow fluid from the inlet end to the outlet end, wherein the channels are defined by porous walls configured to trap particulate matter. The porous walls may have a total porosity greater than about 45%, a median pore size ranging from about 13 micrometers to about 20 micrometers, and a pore size distribution such that pores less than 10 micrometers contribute less than about 10% porosity.

Abstract: A particulate filter may comprise an inlet end, an outlet end, and a plurality of channels disposed and configured to flow fluid from the inlet end to the outlet end, wherein the channels are defined by porous walls configured to trap particulate matter. The porous walls may have a cell density less than about 200 cpsi, a wall thickness of less than about 14 mils, a median pore size that ranges from about 13 micrometers to about 20 micrometers, a total porosity greater than about 45%, and a pore size distribution such that pores less than 10 micrometers contribute less than about 10% porosity.

Abstract: A method for regenerating a particulate filter may comprise calculating a first estimated soot load of a particulate filter based on a pressure drop of an exhaust gas flowing through the particulate filter, and calculating a second estimated soot load of the particulate filter based on a mass balance of soot in the particulate filter. The method may further comprise calculating a hybrid estimated soot load based on the first estimated soot load and the second estimated soot load, wherein calculating the hybrid estimated soot load comprises applying at least one gate so as to weight a relative contribution of each of the first estimated soot load and the second estimated soot load to the hybrid estimated soot load, and causing regeneration of the particulate filter when the hybrid estimated soot load is greater than or equal to a threshold value.

Abstract: A method for regenerating a particulate filter may comprise determining a temperature, a flow rate, and a total pressure drop of an exhaust gas flowing through a particulate filter, and determining a corrected soot layer permeability. The method may further comprise calculating an estimated soot load of the particulate filter based on the total pressure drop and the corrected soot layer permeability, and causing regeneration of the particulate filter when the estimated soot load is greater than or equal to a threshold value.

Abstract: Systems and methods are provided for controlling an exhaust stream temperature at a point along an exhaust system. The exhaust system can include an oxidation catalyst, a particulate filter having an outlet, and a fuel injector for injecting fuel into an exhaust stream at a location upstream from the outlet. An adaptive control can be provided to model a portion of the exhaust system. A fuel injection flow rate at which fuel is injected into the exhaust stream by the fuel injector can be calculated based on the adaptive control model. An operation of the fuel injector can be controlled based on the calculated fuel injection flow rate, to control the exhaust stream temperature at point along the exhaust system. A condition of the exhaust stream can also monitored and an error in the adaptive control model can be determined based on the monitored condition. The adaptive control model can also be changed to reduce the error.

Abstract: Porous ceramic diesel particulate filters are regenerated to combust accumulated carbon particulates trapped therein through a controlled regeneration process wherein heat is input to the filter at a ramped or staged heating rate below that rate at which the particulate combustion process would proceed so rapidly and extensively that filter temperatures would be raised to filter-damaging levels.

Abstract: A thin-walled porous ceramic wall-flow filter is disclosed. The filter produces a relatively lower pressure drop coupled with relatively high initial filtration efficiency (FE0), and may enable packaging the filter in a smaller volume. The filter includes a plurality of porous ceramic walls forming cell channels. At least some of the cells are plugged forcing some exhaust gases through the walls, thereby filtering out entrained particulates. The walls have a wall thickness (Twall) wherein 102 ?m?Twall<279 ?m, and a median pore diameter (MPD), and wherein 10<Twall/MPD, and may also be <40. The relatively small median pore diameter (MPD) in comparison to the wall thickness (Twall) allows the use of thinner ceramic walls that provide less flow resistance than thicker walls while maintaining sufficient initial filtration efficiency (FE0). Furthermore, such thin-walled filter structure coupled with unequal inlet/outlet area ratio (Ai/Ao) may allow filter lengths to be additionally shortened.

Abstract: A method for regenerating a diesel particulate filter includes elevating a temperature of a gas stream flowing into an inlet of the diesel particulate fitter to greater than or equal to 450° of the inlet of the diesel particulate filter, wherein the gas stream at the inlet of the diesel particulate fitter contains an amount of NOx of equal to or greater than 300 ppm, and an amount of O2 of equal to or greater than 5% volume, thereby burning the soot within the diesel particulate fitter. The method also includes elevating a temperature of the gas stream flowing into the inlet of the diesel particulate filter to less than or equal to 550° C. at the inlet of the diesel particulate fitter, wherein a burn rate of soot from porous watts of the diesel particulate filter is greater than or equal to 3.8 grams/liter/hour.

Abstract: A exhaust system and method for venting exhaust from an engine, such as a diesel engine, through an exhaust line coupled to the engine includes a first particulate filter disposed in the exhaust line and “close-coupled” with the engine, and a second particulate filter spaced a distance (d) from the first filter. The first particulate filter is “close-coupled” so that it operates in a passive regeneration mode to a greater extent than the second particulate filter. The first particulate filter may be a partial wall-flow filter including some plugged and some open channels. Some of the plugged channels may be plugged adjacent to an inlet end and others may be plugged adjacent to an outlet end. A partial wall-flow filter is also described having some unplugged flow-through channels and some plugged channels wherein some plugged channels are located adjacent to the inlet end and some are located adjacent to the outlet end.