Abstract: A method is provided for controlling a Diesel Emission Fluid (DEF) injected quantity in a NOx reduction system employing a Selective Catalytic Reduction (SCR) catalyst, and a DEF injector for injecting the DEF to reach said SCR catalyst. The method includes determining a required quantity of DEF for the SCR catalyst at a given time. If the required quantity of DEF is at least equal to a threshold quantity, then a DEF injection is activated, otherwise the required quantity of DEF is stored in memory of an Electronic Control Unit (ECU). After a period, a further required quantity of DEF to be added to the required quantity is determined to determine a new required quantity of DEF. The new required quantity of DEF is continuously updated until the new required quantity of DEF is at least equal to said threshold quantity, at which point the DEF injection of the new required quantity of DEF is activated.

Abstract: An air-fuel ratio control device is provided for controlling the air-fuel ratio of an engine. The device includes an exhaust passage having a main catalytic converter and a bypass passage having a bypass catalytic converter, the bypass passage diverging from the exhaust passage at an upstream junction and rejoining the exhaust passage at a downstream junction. A valve mechanism disposed in the exhaust passage between the upstream junction and the downstream junction moves between a closed state and an open state. During a predetermined period of time after the valve mechanism opens to permit flow in the exhaust passage, the air-fuel ratio of the engine is controlled based on a signal from a first air-fuel ratio sensor in the bypass passage using a low response correction value that is less than a normal response correction value that would be used when the valve mechanism is closed.

Abstract: Embodiments for controlling exhaust oxygen concentration are provided. In one example, an engine method comprises operating the engine with lean combustion, and when exhaust oxygen concentration is below a threshold, injecting air into an exhaust passage between a first emission control device and an SCR device. In this way, excess emissions may be converted while operating with lean combustion.

Abstract: Systems and methods are provided for managing low temperature NOx and HC emissions, such as during a cold start of an internal combustion engine. The systems and methods include storing NOx and HC emissions at low temperatures and passively releasing these emissions as the temperature of the exhaust system increases.

Abstract: The exhaust purification system of an internal combustion engine of the present invention is provided with an NOX storage reduction catalyst and a particulate filter which is arranged at the upstream side of the NOX storage reduction catalyst. When causing the NOX storage reduction catalyst to release the stored NOX, the particulate filter is raised to the temperature at which the particulate matter is oxidized, the flow rate of the exhaust gas which flows into the particulate filter is made to decrease, the air-fuel ratio of the exhaust gas which flows into the particulate filter is made rich, and the particulate matter which builds up on the particulate filter is made to oxidize to produce carbon monoxide.

Abstract: A particulate filter regeneration system may include an exhaust inlet, an exhaust chamber coupled downstream of the exhaust inlet, an exhaust outlet, and a flow-through wall coupled between the exhaust chamber and the exhaust outlet. The particulate filter regeneration system may further include a heater for heating the particulate filter regeneration system to enable particulate combustion and a bypass coupled to the exhaust chamber for selectively opening a filter regeneration pathway to remove accumulated particulate.

Abstract: A system and method includes an internal combustion engine capable of producing an exhaust stream and an aftertreatment system operationally coupled to the exhaust stream. The aftertreatment system includes an upstream selective reduction catalyst (SCR) component and a downstream SCR component that are positioned in substantially different thermal environments. The upstream and downstream SCR components are sized to fully treat the entire exhaust stream at a low temperature highest NOx conversion condition, and the downstream SCR component is sized to fully treat the entire exhaust stream at a high temperature highest NOx conversion condition.

Abstract: A diesel emission fluid (DEF) injection system for a machine is disclosed. The machine includes a fan or a source of flowing air, as well as a first portion of an exhaust system coupled to an exhaust after-treatment device and a second portion of the exhaust system disposed below the exhaust after-treatment device. The DEF injection system includes a DEF line in selective communication with the first portion of the exhaust system as well as electrical components such as an electrically activated valve for injecting the DEF into the first portion of the exhaust system. To maintain the electrical components at acceptably low temperatures, a heat shield is disposed between the electrical components and the second portion of the exhaust system and an air duct is provided that communicates air from the fan or source of flowing air towards the electrical components for forced air cooling.

Abstract: Provided is an exhaust purification system capable of clearing a blockage of a reducing agent injection valve caused by solidification of an aqueous urea solution soon after starting an engine and preventing degradation in exhaust purification efficiency when starting an internal combustion engine.

Abstract: A method for operating an exhaust gas treatment device having at least one heater and at least one supply device for a reducing agent includes initially carrying out a test in order to determine if the reducing agent is to be supplied, and subsequently implementing different heating strategies in each case. In the event that the reducing agent is to be supplied, the exhaust gas treatment device is heated with the heater until a first threshold temperature is reached, if a first temperature lies below the first threshold temperature. In the case when no reducing agent is to be fed, the exhaust gas treatment device is heated with the heater until a second threshold temperature is reached, if a second temperature lies below the second threshold temperature. A motor vehicle having the device is also provided.

Abstract: Particles of mixed oxides of cerium, zirconium, and copper (CeZrCuOx) may be prepared as catalysts and used to preferentially catalyze the oxidation of CO in exhaust streams containing CO and NH3. In one practice, this CeZrCuOx catalyst may be used in combination with a close-coupled PGM catalyst which promotes the formation of NH3 in the exhaust during fuel-rich operation, and at least one under-floor NH3-SCR catalyst, which catalyzes the reduction of NOx in the exhaust stream during fuel-lean operation using NH3 as a reductant. During fuel-rich engine operation, the exhaust stream may be doped with oxygen downstream of the PGM catalyst and passed in contact with particles of the CeZrCuOx catalyst so that residual CO in the exhaust may be oxidized to CO2, without oxidation or other conversion of the NH3.

Abstract: A method for operating a tank for reducing agent, in particular aqueous urea solution, having a sensor with a first electrical contact and a second electrical contact, includes initially determining a conductance value for liquid reducing agent, a conductance value for frozen reducing agent and a conductance value for air in steps a.1) to a.3. A voltage is then applied between the first electrical contact and the second electrical contact in step b. A conductance value between the first electrical contact and the second electrical contact is then determined in step c. The conductance value determined in step c) is then compared to the conductance values determined in steps a.1) to a.3) and a determination is made as to if liquid reducing agent, frozen reducing agent, or air is present in step d). A motor vehicle in which the method is carried out, is also provided.

Abstract: An exhaust purification apparatus for an internal combustion engine according to the present invention includes a heated gas generation apparatus configured to generate heated gas utilizing exhaust gas flowing through an exhaust passage. The heated gas generation apparatus includes a catalyst configured to provide an oxidation function, a fuel supply nozzle, and a heater. An exhaust purification unit is provided downstream of the heated gas generation apparatus. An incoming gas temperature of the exhaust purification unit is detected and estimated. An actual incoming gas temperature being a detected value and an estimated incoming gas temperature both acquired when at least the fuel supply nozzle is actuated are compared with each other. Based on the result of the comparison, the apparatus detects one of poisoning of the catalyst with HC and degradation of the catalyst. Thus, the heated gas generation apparatus is prevented from discharging HC.

Abstract: An exhaust gas treatment system for an internal combustion engine is provided, including an exhaust gas conduit, a pressurized vessel, a selective catalytic reduction (“SCR”) device, and a control module. The internal combustion engine has a plurality of pistons and an engine off condition that indicates that the pistons are generally stationary. The exhaust gas conduit is in fluid communication with, and configured to receive an exhaust gas from the internal combustion engine. The pressurized vessel stores a solid ammonia gas producing material. The pressurized vessel is selectively activated to heat the solid ammonia gas producing material into an ammonia gas. The ammonia gas is released into the exhaust gas conduit. The SCR device is in fluid communication with the exhaust gas conduit and is configured to receive the ammonia gas.

Abstract: An exhaust gas treatment apparatus for a working machine is provided to reliably prevent a specific process that raises the exhaust temperature of an exhaust gas treatment section from being carried out during switching operation of a directional control valve.

Abstract: The present invention provides an exhaust purification apparatus for an internal combustion engine which enables a decrease in NOx purification rate and possible ammonia slip to be inhibited. The apparatus includes an NOx catalyst, a urea aqueous solution addition valve serving as reducing agent adding means, and NOx sensors provided an inlet and an outlet of the NOx catalyst, respectively. When the bed temperature of the NOx catalyst is in a predetermined high-temperature region in which the amount of ammonia converted into NOx increases relatively and an NOx purification rate decreases relatively, the apparatus uses outputs from the NOx sensors to perform correction such that the actual addition amount of the urea aqueous solution addition valve reaches a target addition amount.

Abstract: A method for operating a metering apparatus for reducing agent includes providing the metering apparatus with at least one movable pump element movable between upper and lower reversal points to convey reducing agent into an exhaust-gas treatment component, and at least one position transmitter for determining a pass of the movable pump element. In the method, a first detection of a position of the movable pump element is provided by the position encoder. Subsequently, the movable pump element is moved and reducing agent is metered into the exhaust-gas treatment component. Thereupon, a second detection of a position of the movable pump element is provided by the position encoder, and subsequently a first quantity of reducing agent which is metered between the first and second detections is determined. A metering apparatus and a motor vehicle having a metering apparatus are also provided.

Abstract: A system and method controls injection of a reductant agent in a selective catalytic reduction system. The system and method include an injector injecting the reductant agent to an exhaust system directing exhaust from a power system. A coolant system circulates coolant proximate to the injector. A coolant temperature sensor monitors a coolant temperature of the coolant. A controller adjusts the injection timing of the injector based at least in part on the coolant temperature.

Abstract: An object of the present invention is to provide an exhaust gas purifying apparatus for an internal combustion engine which can properly purge at least NOx of unpurified components contained in exhaust gas while considering characteristics of NOx desorbed from an adsorbent. A bypass passage 18 bypassing a main exhaust passage 12 of the internal combustion engine 10 is provided. A HC/NOx adsorbent 22 having a function of adsorbing HC and NOx is provided in the bypass passage 18. A second underfloor catalyst 30 is provided downstream of the adsorbent 22. A purge passage 26 branching off from the bypass passage 18 while connecting to an intake passage is provided. An exhaust switching valve 20 and a purge control valve 28 are provided as a flow path switching means that is capable of switching a flow target into which the exhaust gas flows between the main exhaust passage 12 and the bypass passage 18. If the purging operations are executed, the intake purging operation is first executed.

Abstract: Methods and systems are provided for controlling an engine in a vehicle, the engine having a turbocharger, and a particulate filter upstream of a turbocharger turbine. In one example, the method comprises, under selected boosted operating conditions, injecting a reductant upstream of the filter during an exhaust stroke to generate an exothermic reaction at the filter.

Abstract: A technique is provided which is capable of reducing an amount of smoke generated in a temperature raising system in which fuel added to an exhaust gas flowing through an exhaust passage is caused to combust at the time of requesting a temperature rise in an exhaust gas purification catalyst. When a request for raising the temperature of an exhaust gas purification catalyst is made, bypass control is carried out in which the exhaust gas having bypassed a turbine is caused to flow into the exhaust gas purification catalyst through a bypass passage, and fuel ignition control is carried out in which a fuel addition valve is caused to add fuel to the exhaust gas which has flowed out of the turbine, and a glow plug is caused to ignite the added fuel.

Abstract: Methods and systems are disclosed for determining a feed rate for direct introduction of a reductant gas into an exhaust stream to achieve a NOx emissions target and for controlling a reductant introduction device to admit the reductant gas into the exhaust stream at the determined feed rate.

Abstract: An exhaust gas treatment system includes a heating module for heating exhaust gas upstream of a main catalytic converter. The heating module includes a first heating core having a first core volumetric size and a second heating core having a second core volumetric size that is less than the first core volumetric size. The first heating core with the larger first core volumetric size is configured to optimize pre-crank heating, while the second heating core with the smaller second core volumetric size is configured to optimize post-crank heating. The first heating core and the second heating core may be arranged in series with each other or in parallel with each other.

Abstract: A control system for a selective catalytic reduction (SCR) system includes a conversion efficiency determination module, an ammonia slip determination module, and a diagnostic module. The conversion efficiency determination module determines a conversion efficiency of an SCR catalyst. The ammonia slip determination module determines an amount of ammonia slip across the SCR catalyst when the conversion efficiency is less than a predetermined threshold. The diagnostic module determines pass/fail statuses of a reductant supply and the SCR catalyst based on the amount of ammonia slip and at least one ammonia slip threshold.

Abstract: The invention relates to a method for correcting a model for determining the amount of reducing agent to inject for the selective catalytic reduction of nitrogen oxides contained in exhaust gases, which includes the following steps: determining an amount of reducing agent to inject based on the amount of nitrogen oxides emitted and an initial mathematical model; determining, by taking a measurement from the catalyst of the amount and/or nature of the gas, whether or not the reducing reaction is carried out under correct conditions; if an anomaly is detected, adjusting the amount of reducing agent to inject; and if the use of said method leads to a number of repeated adjustments of the same nature greater than a predetermined value N: the mathematical model is corrected, and the initial mathematical model is replaced by the corrected model.

Abstract: Method for controlling regeneration within an after-treatment component of an engine comprises receiving an upstream temperature signal, receiving a downstream temperature signal, and calculating a temperature difference based on a difference between the upstream temperature signal and the downstream temperature signal. The temperature difference is compared to a predetermined temperature change limit to determine whether the temperature difference is less than or greater than the predetermined temperature change limit. If the temperature difference is less than the predetermined temperature change limit, an estimate of accumulated particulate matter in the after-treatment component is calculated using a primary soot accumulation model. If the temperature difference is greater than the predetermined temperature change limit, an estimate of accumulated particulate matter in the after-treatment component is calculated using a secondary soot accumulation model.

Abstract: An object is to provide a technology with which the temperature of exhaust gas can be raised with improved efficiency in cases where a catalyst apparatus including a catalyst having an oxidizing ability is provided in an exhaust passage of an internal combustion engine. According to the present invention, a catalyst apparatus 6 that is provided in the exhaust passage 1 of the internal combustion engine and to which reducing agent is supplied from upstream when the temperature of the exhaust gas is to be raised is equipped with at least first and second catalysts 4, 5 having an oxidizing ability. The first catalyst 4 is configured in such a way that the exhaust gas flows through a gap between its outer circumferential surface and the inner circumferential surface of the exhaust passage. The second catalyst 5 is disposed downstream of the first catalyst 4 with a space 10 having a specific width Ws between it and the first catalyst 4.

Abstract: An exhaust control system comprises a nominal specific heat module, a correction module, a specific heat determination module, and a convective loss estimation module. The nominal specific heat module determines a nominal specific heat of exhaust input to a component of an exhaust system based on a temperature of the exhaust input to the component and based on a predetermined oxygen content. The correction module determines a specific heat correction based on an oxygen content measured by a sensor. The specific heat determination module determines a specific heat of the exhaust based on the nominal specific heat and the specific heat correction. The convection loss estimation module estimates a convective energy loss rate associated with the component based on the specific heat.

Abstract: Apparatus for controlling an internal combustion engine limits emission of undesirable compounds of nitrogen and oxygen and provides increased transient power.

Abstract: A warming-up system performing a catalytic converter warming-up method has an electric motor (1m) enabling a turbocharger (1) to increase the amount of air supplied to an internal combustion engine (2) regardless of the amount of exhaust gas flowing through a turbine (1t) of the turbocharger (1), a variable nozzle (1n) regulating the flow of exhaust gas through the turbine (1t), and an ECU (5) for controlling the operation of the electric motor (1m) and the variable nozzle (1n) and the amount of fuel supplied to the internal combustion engine (2). After the internal combustion engine (2) is started, the ECU (5) warms up the catalytic converter (4) by driving the electrical motor (1m) to forcibly rotate the turbine (1t), opening the variable nozzle (1n), and increasing fuel supply to the internal combustion engine (2).

Abstract: An exhaust line of an internal-combustion engine contains a catalyst and a bypass pipe bypassing the catalyst. The bypass pipe can be shut-off by way of a shut-off valve. The shut-off valve has a diagnostic device for diagnosing a tightness of the shut-off valve.

Abstract: A moisture adsorbent (32) for adsorbing moisture in exhaust gas and an NOx adsorbent (34) for adsorbing NOx are disposed in a bypass passage (30) for bypassing an exhaust passage (16) of an internal combustion engine (10). When an adsorption operation to the NOx adsorbent (34) is executed, inflow of the exhaust gas to the bypass passage (30) is allowed until the moisture amount that flows into the water adsorbent (32) reaches an allowable moisture inflow amount. The allowable moisture inflow amount is determined based on a residual moisture amount before the starting of the adsorption operation in the moisture adsorbent (32). The residual moisture amount in the water adsorbent (32) can be determined based on the temperature of the moisture adsorbent (32) at the immediately preceding execution of the purge operation.

Abstract: Method to reduce NOx contained in an exhaust gas by including an oxidation catalyst device and a selective reduction type NOx catalyst device, which are arranged in this order from an upstream side, and a NOx purification system. Whether a volume of NO2 adsorbed in the oxidation catalyst device increases or decreases is estimated, and a flow rate of exhaust gas which bypasses the oxidation catalyst device on a basis of the increase or decrease in the estimated volume of adsorbed NO2 is controlled. This avoids incorrect supply of ammonia.

Abstract: An exhaust gas treatment system for an internal combustion engine is provided, having an exhaust gas conduit, a reductant source, a temperature sensor, an intake mass air flow sensor, and a control module. The exhaust gas conduit is in fluid communication with, and is configured to receive an exhaust gas from the internal combustion engine. The exhaust gas contains oxides of nitrogen (“NOx”). The reductant source is in fluid communication with the exhaust gas conduit and is configured for injecting an amount of reductant that is released into the exhaust gas conduit. The temperature sensor is situated in the exhaust stream for determining a temperature of the exhaust gas at the reductant source. The intake mass air flow sensor measures an air mass flow entering the internal combustion engine. The control module is in communication with the reductant source, the temperature sensor, and the intake mass air flow sensor.

Abstract: A configuration for purifying or cleaning an exhaust-gas flow of an internal combustion engine includes at least an ionization device, an agglomeration device, and a (catalytically active) radial honeycomb body around a duct. The exhaust-gas is diverted from the duct into the radial honeycomb body, while the agglomerated particles are caught in a particle separator of the duct. A method for purifying or cleaning an exhaust-gas flow of an internal combustion engine and a motor vehicle including an exhaust system having the configuration, are also provided.

Abstract: An exhaust emission purification system having a controller performing exhaust temperature rise control including multistage delay injection control for raising the exhaust temperature, if the exhaust gas temperature is lower than a predetermined judgment temperature, and performing particulate matter combustion removal control including post injection control, if the exhaust gas temperature becomes equal to or higher than the predetermined judgment temperature, when forced regeneration of a diesel particulate filter is carried out. The multistage delay injection control is forbidden when an idle operation state of an internal combustion engine occurs for a predetermined judgment time and a power take-off device is operating.

Abstract: A method pertaining to an SCR system which includes a dosing unit (250) to supply reducing agent to an exhaust duct (240) for exhaust cleaning, and a container for reducing agent: the steps of determining (s320) a cooling requirement of the dosing unit (250) and choosing (s340) a limit level for reducing agent in the container (205) on the basis of the cooling requirement. A computer programme product containing programme code (P) implements a method according to the invention. A device of an SCR system includes a dosing unit (250) to supply reducing agent to an exhaust duct (240) for exhaust cleaning. A motor vehicle (100) is equipped with the device.

Abstract: A method of controlling the temperature of a thermoelectric generator (TEG) in an exhaust system of an engine is provided. The method includes determining the temperature of the heated side of the TEG, determining exhaust gas flow rate through the TEG, and determining the exhaust gas temperature through the TEG. A rate of change in temperature of the heated side of the TEG is predicted based on the determined temperature, the determined exhaust gas flow rate, and the determined exhaust gas temperature through the TEG. Using the predicted rate of change of temperature of the heated side, exhaust gas flow rate through the TEG is calculated that will result in a maximum temperature of the heated side of the TEG less than a predetermined critical temperature given the predicted rate of change in temperature of the heated side of the TEG. A corresponding apparatus is provided.

Abstract: An electronic control unit executing an algorithm so as to operate an exhaust purification system of an engine. The algorithm (1) commences a regeneration treatment by causing an amount of fuel supplied to a combustion process of the engine to increase so as to change an air-fuel ratio of exhaust gas of the engine from a first lean air-fuel ratio to a set rich air-fuel ratio and (2) causes uncombusted fuel to be supplied to a NOx catalyst device during at least one of: a first period in which an air-fuel ratio of the exhaust gas within the NOx catalyst device changes from the first lean air-fuel ratio to the set rich air-fuel ratio when the regeneration treatment is started; and a second period after an air-fuel ratio of the exhaust gas within the NOx catalyst device becomes a ratio indicating completion of the regeneration treatment.

Abstract: An exhaust system (16) of a diesel engine (10) has a diesel particulate filter (18) for treating exhaust gas. When trapped soot has accumulated to an extent that may affect performance of the filter, an engine control system (12) forces combustion of trapped soot by increasing exhaust back-pressure using a control device (20) such as a back-pressure control valve or vanes of a variable geometry turbocharger.

Abstract: An ammonia dosing system has a canister whose interior contains ammonia luminophores and a delivery apparatus for delivering ammonia from the canister interior into an exhaust after-treatment system to entrain with engine exhaust flowing toward an SCR catalyst for catalytic conversion of NOx in engine exhaust.

Abstract: An exhaust system for an internal combustion engine, having a first exhaust tract assigned to a first group of cylinders of the internal combustion engine, and having a second exhaust tract assigned to a second group of cylinders of the internal combustion engine, each exhaust tract comprising an exhaust gas purification device, a first silencer arranged on the outlet side of the respective exhaust gas purification device, and a second silencer arranged on the outlet side of the respective first silencer. Each exhaust tract includes a bypass line, it being possible for exhaust gas to be diverted via each bypass line, starting from the respective first silencer, bypassing the second silencers, and the bypass lines and hence the first silencers of both exhaust tracts being connected to one another by a mixing line.

Abstract: Various systems and methods are described for controlling an engine in a vehicle during engine operation, the engine having an exhaust and a NOx sensor coupled in the engine exhaust, in response to an ambient temperature of the NOx sensor. One example method comprises, during warm-up of the NOx sensor and during cold engine starting, adjusting an engine operating condition in response to a NOx-indicative reading of the NOx sensor, the NOx-indicative reading being compensated for ambient temperature effects on the NOx sensor.

Abstract: Methods and systems for treating NOx-containing exhaust from an internal combustion engine. An exhaust aftertreatment system has at least a primary oxidation catalyst, a particulate filter, and a selective reduction catalyst (SCR). A bypass line diverts a portion of the exhaust from the exhaust line from a point downstream the particulate filter to a point upstream the SCR. A secondary oxidation catalyst on the bypass line is used to generate NO or NO2 to be returned to the exhaust line upstream the SCR.

Abstract: A dosing control system for a vehicle includes a pump control module and an enabling/disabling module. The pump control module controls a pump that provides dosing agent to a dosing agent injector located upstream of a selective catalytic reduction (SCR) catalyst in an exhaust system. The enabling/disabling module disables the pump for a predetermined melting period after engine startup when the dosing agent is frozen and selectively activates the pump during the predetermined melting period to cool the dosing agent injector when a tip temperature of the dosing agent injector is greater than a predetermined temperature.

Abstract: The invention relates to an exhaust component in a gas exhaust line for gases produced by the combustion of a fuel in a heat engine. In the gas flow direction, there is a first connection to an upstream pipe carrying gases from the engine. There is also a first exhaust tube and a second exhaust tube, these two tubes being parallel and being connected to the first connection. There is a second connection to a downstream gas discharge pipe, connected to the parallel exhaust tubes. The component is characterized in that, firstly the first tube has a depolluting component, and the second tube has a silencer. The second connection is a three-way valve.

Abstract: A urea solution heating device prevents freezing of a urea solution by using exhaust gas of an engine. More particularly, a urea solution heating device may use a pressure difference between an exhaust gas pipe and a muffler to bypass the exhaust gas to exchange heat between the exhaust gas and the urea solution. The urea solution heating device may include an exhaust gas pipe, a muffler, a first bypass pipe diverged from the exhaust gas pipe, a urea solution tank to which the bypassed exhaust gas is supplied, a second bypass pipe connected to the muffler, and a heat exchanger, wherein the exhaust gas sequentially flows through the first bypass line, the heat exchanger, and the second bypass line by a pressure difference between the exhaust gas pipe and the muffler. An urea solution heating method is also described.

Abstract: A control system for a pump in a vehicle exhaust system includes a pump having an inlet port and an outlet port, a fluid supply in fluid communication with the inlet port, and a supply line in fluid communication with the outlet port. The supply line is configured to deliver fluid to an exhaust component. A controller is configured to adjust pump flow rate to maintain a desired pressure in the supply line. A restriction is utilized in a return flow path from the supply line.

Abstract: A dosing apparatus with purging means for delivering reductant into an exhaust gas treatment system of an internal combustion engine. The apparatus includes a first Venturi T connector with two high pressure ports and a low pressure port, and a purge control valve for switching from normal dosing to purging by controlling flow through the two high pressure ports. The apparatus may also include a second Venturi T connector and a reductant supply chamber for purging reductant residue in its pump and reductant passage lines. The apparatus may further include a purging controller that triggers a purging event according to engine oil or coolant temperature and controls the purging process after a dosing process completes.

Abstract: Systems and methods are provided for operating a particulate matter retaining system having at least a first and a second filter, coupled to an engine intake. One example method comprises, during a first condition, operating in a first mode with the first filter storing particulate matter and the second filter releasing stored particulate matter. The method further comprises, operating in a second mode with the first filter releasing stored particulate matter and the second filter storing particulate matter, the exhaust gas flowing in an opposite direction as compared to the first mode. The method further comprises, operating in a third mode with both the first and the second filter storing particulate matter. During the modes, at least some tailpipe gas is drawn from between the first and second filters for expulsion to the atmosphere.