A reagent dosing system includes an injector having an outlet configured to be in fluid communication with the exhaust conduit; a reagent tank configured to hold a volume of reagent; a water tank configured to hold a volume of water; and a means for 1) pumping reagent from the reagent tank to the injector for injection of reagent into the exhaust conduit and 2) pumping water from the water tank to the injector for flushing residual reagent from the injector.

An internal combustion engine system includes: an internal combustion engine mounted on a vehicle; a NOx selective reduction catalyst; a reducing agent supply device including a urea water addition valve configured to add urea water into the exhaust gas passage upstream of the NOx selective reduction catalyst, a urea water tank, a urea water flow passage that connects the urea water addition valve and the urea water tank, and a pump configured to supply the urea water addition valve with the urea water from the urea water tank; and a control device. The control device is configured to perform a runoff reduction control that controls at least one of the reducing agent supply device and the internal combustion engine such that the amount of runoff of the urea water from the urea water tank becomes less when the tilt angle of the vehicle is large than when it is small.

A lance injector assembly for an exhaust component is provided. The lance injector assembly includes a lance and a poppet valve. The lance includes a lance housing, a supply passage fluidly coupled to a reductant source and terminating at a nozzle orifice, and a return passage fluidly coupled to the reductant source. The poppet valve is positioned downstream of the nozzle orifice and includes a poppet movable between a closed position and an open position. When operating in a recirculation mode, the poppet is in the closed position to permit a full portion of reductant supplied to the lance from the reductant source to return to the reductant source. When operating in an injection mode, the poppet is in the open position to permit a first portion of reductant to flow from the nozzle orifice and a second portion of reductant to return to the reductant source.

A fluid injector for injecting an injection fluid into a hot flow can include a flow structure defining an injection flow channel and configured to extend at least partially into a flow path to introduce the injection fluid into the hot flow in the flow path. The flow structure can include one or more heat resistance features to protect the flow structure and the fluid from heat of the hot flow.

A method for operating a feed module of an SCR catalytic converter system which has a feed pump, a feedback pump and a hydraulic interface channel. The feed module is operated in a test state in which a feed operation of the feed pump takes place and a feed operation of the feedback pump does not take place. Owing to a time profile of an MSP current (I.sub.MSP) of the feed pump it is decided in the test state whether the feed module is to change into a thawing state.

The present application provides a reductant dosing system for an SCR catalyst comprising an injector, a storage tank and a reductant pump arranged in a first fluid line between the storage tank and the injector for pumping reductant from the storage tank to the injector. The reductant dosing system comprises pressurizing means for pressurizing the storage tank.

The invention relates to a method for emptying a reducing agent delivery system belonging to an SCR catalytic converter, which comprises a delivery line and a return line, each line connecting a reducing agent tank to a delivery module, and which comprises a pressure line that connects the delivery module to a metering valve. The method comprises the following steps: closing (50) the metering valve, and switching the delivery module from a delivering function to a returning function, by switching (51) a switching valve from a first position to a second position. This enables a reducing agent solution to be returned (52) from the return line, the delivery line and the delivery module by means of the delivery module and the delivery line into the reducing agent tank. Subsequently, the metering valve is opened (53) and a reducing agent solution is returned (54) from the metering valve and the pressure line, and also from the return line, via the delivery line into the reducing agent tank. Additionally, the metering valve is closed again (55) in order to empty (56) the return line and the delivery module.

An injection controller that is applied to an exhaust purification system including an injector that is located in an exhaust passage of an internal combustion engine and injects to supply a reducing agent in a liquid state to a NOx purification catalyst purifying NOx in an exhaust gas, and a pump that pressurizes and pumps the reducing agent to the injector through a reducing-agent passage. The injection controller includes an acquisition unit configured to acquire a variation quantity of a rotational speed of the pump caused in response to an injection of the injector or a correlation value that is a value correlative to the variation quantity, as a rotational variation parameter, and a determination unit configured to determine whether an air mixing exists in the reducing-agent passage based on the rotational variation parameter.

The present disclosure provides a reductant injection system for an SCR catalyst of an internal combustion engine, the reductant injection system comprising at least one injector, a first storage container for storing liquid reductant and a pump for pumping reductant from the first storage container to the injector for injection into an exhaust gas stream, wherein the injector is cooled by reductant. The reductant injection system may comprise a second storage container for storing liquid reductant and is configured such that the injector can be cooled by reductant from the second storage container.

A diesel exhaust fluid delivery system and a dual-variable control strategy for adjusting the delivery pressure and the mass flow rate of the fluid passing through the system. The method for operating the system using two operating modes: low flow rate and high flow rate. While operating in the low flow rate operating mode, the speed of a DEF pump remains constant and DEF delivery to the exhaust system is adjusted by controlling a backflow valve. While operating in the high flow rate operating mode, the backflow valve is closed and the speed of the pump is adjusted to regulate DEF delivery to the exhaust system.