Abstract: A system and a process for storing an additive solution and injecting it into the exhaust gases of an internal combustion engine. The system comprises at least one tank for storing the additive, one pump equipped with an inlet and an outlet and that is capable of generating a direct flow (in injection mode) or a reverse flow (in drawing off mode), at least two additive solution suction points, and an injector, wherein a first suction point is connected to the pump inlet and is only active when the pump operates in injection mode, and wherein the second suction point is connected to the pump outlet and is only active when the pump operates in drawing off mode.

Abstract: Method for controlling an injector intended for injecting a pollution-control liquid additive into the exhaust gases of an internal combustion engine at a flow rate governed by a given frequency and opening time of the injector, the injector having a calibration curve that establishes, at given frequency, pressure, temperature and nature of the liquid, the amount of liquid injected during an opening of the injector as a function of the duration of this opening, this curve comprising at least one linear zone (calibration line) and a non-linear zone, said method being characterized in that in the linear zone the parameters of the calibration line are used and in the non-linear zone use is made of a set opening time and a variable frequency according to at least one calibration point established for this purpose. SCR system to which this method can be applied.

Abstract: Method for heating a urea SCR system using at least two resistive heating elements (R1, R2), one of which (R1) is intended for heating one or some (part(s) of) component(s) always in contact with a substantial amount of urea and the other (R2) is intended for heating one or some (part(s) of) component(s) which are sometimes not in contact with a substantial amount of urea, and according to which, when starting the system in freezing conditions, the resistive element R1 is activated but the resistive element R2 is activated only when its component is actually in contact with a substantial amount of urea.

Abstract: A system and a process for storing an additive solution and injecting it into the exhaust gases of an internal combustion engine. The system comprises at least one tank for storing the additive, one pump equipped with an inlet and an outlet and that is capable of generating a direct flow (in injection mode) or a reverse flow (in drawing off mode), at least two additive solution suction points, and an injector, wherein a first suction point is connected to the pump inlet and is only active when the pump operates in injection mode, and wherein the second suction point is connected to the pump outlet and is only active when the pump operates in drawing off mode.

Abstract: Method for controlling an injector intended for injecting a pollution-control liquid additive into the exhaust gases of an internal combustion engine at a flow rate governed by a given frequency and opening time of the injector, the injector having a calibration curve that establishes, at given frequency, pressure, temperature and nature of the liquid, the amount of liquid injected during an opening of the injector as a function of the duration of this opening, this curve comprising at least one linear zone (calibration line) and a non-linear zone, said method being characterized in that in the linear zone the parameters of the calibration line are used and in the non-linear zone use is made of a set opening time and a variable frequency according to at least one calibration point established for this purpose. SCR system to which this method can be applied.

Abstract: Method for heating a urea SCR system using at least two resistive heating elements (R1, R2), one of which (R1) is intended for heating one or some (part(s) of) component(s) always in contact with a substantial amount of urea and the other (R2) is intended for heating one or some (part(s) of) component(s) which are sometimes not in contact with a substantial amount of urea, and according to which, when starting the system in freezing conditions, the resistive element R1 is activated but the resistive element R2 is activated only when its component is actually in contact with a substantial amount of urea.