Device and Method for Regulating the Injection of a Quantity of Reducer in the Gaseous Phase

Abstract

The invention relates to a device ( 16 ) for regulating the injection of a quantity of reducer in the gaseous phase, comprising: a reducer supply channel ( 18 ), a pressure regulator ( 20 ) for regulating the pressure in the channel, members ( 24 ) for detecting the pressure downstream of the regulator ( 20 ), a reducer injector ( 22 ), and a computer controlling the injector according to the measured pressure.

1 . A device for regulating the injection of a quantity of reducer in gaseous phase comprising a line supplying the reducer, a pressure regulator in the line, pressure detection instruments downstream of regulator, a reducer injector, and a processor controlling the injector as a function of the measured pressure. 
     
     
         2 . The device according to  claim 1 , further comprising pressure detection instruments upstream of regulator. 
     
     
         3 . The device according to  claim 1 , further comprising a temperature sensor downstream and/or upstream of the pressure regulator. 
     
     
         4 . The device according to  claim 1 , the regulator further comprising a first reducer entry chamber, a second chamber routing the reducer towards the injector, a reducer passage between the first chamber and the second chamber, whereby the reducer passage is blocked above a certain pressure threshold in the second chamber and the reducer passage is open below this pressure threshold. 
     
     
         5 . The device according to  claim 4 , wherein the reducer passage is in a piston rod that extends between the first and second chambers, the rod supporting a piston head which is movable axially in the second chamber, and a spring that pushes against the piston head and is suitable for opening the reducer passage when the pressure in the second chamber is lower than the threshold pressure and suitable for closing the reducer passage when the pressure in the second chamber is higher than the pressure threshold. 
     
     
         6 . The device according to  claim 1 , further comprising a post treatment line for exhaust gas, having one or more reservoirs for storing reducer in gaseous phase. 
     
     
         7 . A method for regulating the injection of a quantity of reducer in gaseous phase in a line comprising the steps of supplying reducer to an injector, regulating the pressure downstream of a regulator, detecting the pressure downstream of the regulator, and, controlling the opening time of the injector by a processor as a function of the measured pressure. 
     
     
         8 . The method according to  claim 7 , of further comprising detecting the pressure upstream of the regulator, and emitting an anomaly signal when the pressure upstream and/or downstream of the regulator is above or below a threshold. 
     
     
         9 . The method according to  claim 7 , whereby a post treatment line comprises a plurality of reservoirs, the method further comprising the step of detecting the pressure upstream of the regulator, and switching the reducer supply to the line from one reservoir to another when the detected pressure upstream of the regulator is beyond a threshold. 
     
     
         10 . The method according to  claim 7 , further comprising a step of measuring the temperature upstream and/or downstream of the regulator, through measurement of the temperature or through the use of a model, whereby the opening time of an injector is also controlled by a processor as a function of temperature.