This exhaust purification system includes: a pump disposed in an exhaust-side purge passage to supply air or purge gas purged from a canister to a catalyst; a three-way valve disposed upstream of the pump in the exhaust-side purge passage and configured to switch the exhaust-side purge passage between a communicating state allowing the pump to communicate with the canister and an atmosphere open state allowing the pump to communicate with the atmosphere; a flow control valve disposed downstream of the pump and configured to control a flow rate of air to be supplied to the catalyst; and a controller configured to, when a request to regenerate the catalyst occurs, control a purge valve, the pump, the three-way valve, and the flow control valve to supply, to the catalyst, purge gas purged from the canister and air by a necessary amount to burn particulates trapped in the catalyst.

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.

A catalyst warming apparatus includes an air blower, a fuel feeder, and an air blowing controller. The air blower is disposed between an engine and a purification catalyst in an exhaust pipe communicating with the engine and is configured to blow air toward the purification catalyst. The fuel feeder is configured to cause the purification catalyst to retain fuel. The air blowing controller is configured to start driving the air blower at a predetermined start timing before a start of the engine.

A control system is provided to a reductant dosing system for actively maintaining the reductant dosing system ready for use by flushing unused reductant that has crystallized at a return valve of the reductant dosing system. The control system includes a controller that can control a manner of operation of specific system hardware that is present in the reductant dosing system to flush the unused reductant from the return valve that could otherwise cause the return valve to remain a flow-blocking condition as a result of the crystallized reductant.

A method (200) for ascertaining an air volume provided by means of an electric air pump (134) in an exhaust system (120) of an internal combustion engine (110), including detecting at least one activation parameter (5) of the air pump and ascertaining (220) a provided air mass flow rate (8) on the basis of a calculation specification from the at least one activation parameter (5) by utilizing an inertia of the air pump (134) and/or an inertia of the air upstream and/or downstream from the air pump (134) and/or a differential pressure from upstream from the air pump to downstream from the air pump. In addition, a processing unit and a computer program for carrying out a method (200) of this type is provided.

A drive device for a motor vehicle includes an exhaust pipe and a secondary air device having a first secondary air path which feeds into the exhaust gas pipe. Disposed in the first secondary air path is a secondary air pump and a secondary air valve. To compensate, for example, fluctuations in the supply voltage of the secondary air pump, provision is made for arrangement in the secondary air path of a Laval nozzle which can be placed downstream of the secondary air valve.

A reductant insertion system for inserting reductant into an aftertreatment system via a reductant injector comprises a reductant insertion assembly comprising a pump operatively coupled to the reductant injector via a reductant delivery line. A compressed gas source is operatively coupled to the reductant injector and provides a compressed gas to the reductant injector for gas assisted delivery of the reductant. A controller is operatively coupled to the compressed gas source and the reductant insertion assembly and configured to determine whether there is a reductant demand for the reductant. In response to there being no reductant demand, the controller stops the pump and activates the compressed gas source for a predetermined time so as to provide compressed gas to the reductant injector at a pressure sufficient to force reductant contained in the reductant injector upstream towards the reductant insertion assembly via the reductant delivery line while the pump is stopped.

A urea solution spray nozzle maybe provided that can suppress the deposit and growth of urea in the urea solution spray nozzle. A urea solution spray nozzle according to at least one present embodiment is such that urea solution flow paths and gas flow paths and are constituted, and urea solution and gas are mixed and injected from an injection port, and a slit, which is a lateral ejection port, is constituted in such a manner that the gas is ejected in the same direction as the injection direction of the urea solution along surfaces of the urea solution spray nozzle, and a water-repellent coating layer is formed on the surfaces of the urea solution spray nozzle.

Arrangement (100) for an exhaust gas aftertreatment system (102), comprising a tank (104) for storing a reducing agent (106); a pump unit arrangement (108) arranged in downstream fluid communication with the tank; a nozzle (110) arranged to inject a flow of reducing agent into the exhaust gas aftertreatment system (102), the nozzle being arranged in downstream fluid communication with the tank, via the pump unit arrangement, by means of a reducing agent conduit (112); an air conduit (114) arranged in fluid communication with the nozzle (110) for delivery of compressed air to the nozzle; and a return conduit (116) arranged in fluid communication between the reducing agent conduit and the tank, the return conduit comprising a return conduit valve arrangement (118), wherein the air conduit (114) is arranged in fluid communication with the reducing agent conduit (112) for controllably delivery of reducing agent to the tank via the return conduit valve arrangement (118) by means of providing compressed air from the air conduit

A urea injection system comprises a fluid conveying apparatus used for extracting a urea solution from a urea tank, several nozzles indirectly connected to the fluid conveying apparatus, and a controller used for controlling the urea injection system. The urea injection system is adapted to process exhaust gas of a plurality of engines at the same time. The nozzles comprise a first nozzle used for injecting a urea solution to a first exhaust pipe of a first engine and a second nozzle used for injecting the urea solution to a second exhaust pipe of a second engine. A plurality of nozzles respectively corresponding to a plurality of engines is arranged in the urea injection system, so as to process exhaust gas of the plurality of engines at the same time by using only one urea injection system.