An exhaust gas purification system includes a tank for storing a fluid and a mounting plate coupled to the tank. A baffle is positioned inside the tank below the mounting plate. The baffle has an outer wall defining an interior cavity and an opening. A sensor is positioned in the interior cavity for detecting a condition of the fluid. A supply conduit extends through the mounting plate into the tank. A return conduit extends through the mounting plate into the tank and has an outlet positioned to discharge a return fluid below the opening and exterior to the baffle and the interior cavity.

An exhaust aftertreatment system includes a pump configured to circulate a reagent, an injector configured to deliver the reagent into an exhaust stream, a sensor configured to (i) measure an operating parameter of the aftertreatment system and (ii) output a signal that indicates a value of the measured operating parameter, and a control module configured to control the injector based on the signal outputted by the sensor. The control module includes a correction coefficient determination module configured to generate a correction coefficient based on the signal outputted by the sensor. The control module further includes an injector control module configured to receive an injector flow control signal, determine a pulse width modulation (PWM) signal based on at least the injector flow control signal, and generate an injector control signal that controls actuation of the injector based on at least the correction coefficient and the PWM signal.

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.

A reductant insertion assembly includes: a first pump configured to pump a predetermined amount of a reductant into a selective catalytic reduction system; a reductant delivery line configured to deliver the reductant to the first pump from a reductant storage tank; a reductant return line configured to return reductant to the reductant storage tank from the first pump; a second pump configured to pump the reductant from the reductant storage tank to the first pump; and a valve selectively moveable between a closed position in which the second pump pumps the reductant through the reductant delivery line to the first pump, and an open position in which the second pump draws air through the valve and pumps the air through at least a portion of the reductant delivery line downstream of the valve and the first pump to purge the reductant insertion assembly of the reductant.

An exhaust after-treatment system has a DEF system with improved DEF purge cycling during which time DEF is returned to a DEF storage tank. The DEF system adapts its methodology based on a condition within the DEF system. A purge valve may be arranged in a doser feed line between a DEF supply module and a DEF doser module. A purging control system may be configured to control the purge valve based on detected states within the DEF system, such as a detected state that corresponds to a plugged DEF doser module. If a plugged doser module is detected, the purge valve may be opened to vent the doser module feed line to atmosphere which allows the DEF to be returned to the DEF storage tank without creating a siphon effect that could draw additional DEF from the DEF storage tank into the supply module.

A reductant insertion assembly includes: a first pump configured to pump a predetermined amount of a reductant into a selective catalytic reduction system; a reductant delivery line configured to deliver the reductant to the first pump from a reductant storage tank; a reductant return line configured to return reductant to the reductant storage tank from the first pump; a second pump configured to pump the reductant from the reductant storage tank to the first pump; and a valve selectively moveable between a closed position in which the second pump pumps the reductant through the reductant delivery line to the first pump, and an open position in which the second pump draws air through the valve and pumps the air through at least a portion of the reductant delivery line downstream of the valve and the first pump to purge the reductant insertion assembly of the reductant.

This valve includes a first chamber, a second chamber, a seat with a liquid passage, a plug movable between i) an open position and ii) a closed position, and a biasing member for urging the plug toward the closed position. The valve includes an actuating member having a face which sustains an actuating pressure. The actuating member is movable between i) an actuation position for opening the plug and ii) a rest position. The valve operates, selectively: in a feed mode, where the plug is open and the actuating member is at rest, the liquid flowing in one direction throughout the second chamber, or in a latch mode, where the plug is closed and the actuating member is at rest, no liquid flowing in the valve, or in a drain mode, where the plug is open, the liquid flowing in the reverse direction throughout the second chamber.

A suction tube for a urea sensor installed in a urea tank comprises a suction pipe and a cover. The suction pipe has a suction opening and a hole extending through a wall of the suction pipe. The cover is disposed on an outside of the suction pipe and covers the hole. When there is an under-pressure in the suction pipe compared to the urea tank, the cover abuts the suction pipe and seals the hole. When there is an overpressure in the suction pipe compared to the urea tank, the cover deforms and allows an excess urea solution to escape through the hole and flow back into the urea tank.

A device for cooling and heating a urea solution to be injected into exhaust gas discharged from an engine in order to reduce nitrogen oxides in the exhaust gas includes an engine including a cooling fan, a coolant pump, and a main cooler; a urea solution tank storing the urea solution and having an embedded heat exchange pipe through which first coolant and second coolant circulates; an additional coolant tank storing the second coolant; a water pump supplying the second coolant from the additional coolant tank to the heat exchange pipe; a valve configured to be opened or closed in order to supply the first coolant and the second coolant to the heat exchange pipe through a supply line, and to move the first coolant and the second coolant, which are discharged from the heat exchange pipe through a discharge line, to rise coolant pump and the additional coolant tank, respectively and a controller for supplying the second coolant to the heat exchange pipe through the supply line when the urea solution temperature exceeds a set temperature and for supplying the first coolant to the heat exchange pipe through the supply line when the urea solution temperature is below or equal to the set temperature, and opening or closing the valve.

An internal combustion engine including a urea-water solution injection in the exhaust system, includes at least one urea-water solution tank, at least one pump, at least one intake line leading to the pump, at least one urea-water solution metering valve which is connected to the pump with the aid of a pressure line, and at least one return line which leads from the pump to the urea-water solution tank and at whose end opposite to the pump a filter element is situated, as well as at least one urea-water solution sensor situated in the urea-water solution tank.