Liquid additive reservoir for selective catalytic reduction system

Abstract

A liquid additive reservoir including a rigid casing delimiting a housing, and a fluid-tight flexible pouch mounted inside the housing of the casing and intended to contain the liquid additive, the flexible pouch being designed to be connected to the exhaust line of an internal combustion engine of a vehicle.

1 . Liquid additive reservoir for a selective catalytic reduction system intended for treating exhaust gases of an internal combustion engine of a vehicle, comprising:
 a rigid casing delimiting a housing, and   a fluid-tight flexible pouch mounted inside the housing of the casing and intended to contain the liquid additive,   wherein the flexible pouch being designed to be connected to an exhaust line of the engine.   
     
     
         2 . Liquid additive reservoir according to  claim 1 , wherein the flexible pouch is made of thermoplastic by blow-moulding. 
     
     
         3 . Liquid additive reservoir according to  claim 2 , wherein the casing is produced by blow-moulding at the same time as the flexible pouch. 
     
     
         4 . Liquid additive reservoir according to  claim 1 , wherein the flexible pouch is made from two flexible films welded together or from two flexible half-shells welded together, the two half-shells being made by injection-moulding or thermoforming. 
     
     
         5 . Liquid additive reservoir according to  claim 1 , wherein the flexible pouch has a neck fitted with means of connection to a liquid additive supply line of the selective catalytic reduction system. 
     
     
         6 . Liquid additive reservoir according to  claim 5 , wherein the means of connection comprise a self-closing valve or a shut-off valve. 
     
     
         7 . Liquid additive reservoir according to  claim 1 , further comprising compression means designed to apply a pressure to the flexible pouch, the compression means preferably comprising a compression spring. 
     
     
         8 . Liquid additive reservoir according to  claim 1 , wherein the flexible pouch comprises, in an upper part, a bulge designed to trap liquid additive vapours. 
     
     
         9 . Selective catalytic reduction system intended to treat exhaust gases of an internal combustion engine of a vehicle, comprising a reservoir according to  claim 1 . 
     
     
         10 . Selective catalytic reduction system according to  claim 9 , further comprising:
 a liquid additive supply line designed to connect the flexible pouch to the engine exhaust line,   an injection device coupled to the supply line and designed to inject the liquid additive into the engine exhaust line, and   a selective catalytic reduction catalytic converter.   
     
     
         11 . Selective catalytic reduction system according to  claim 10 , further comprising a pump coupled to the supply line and designed to carry the liquid additive from the flexible pouch to the engine exhaust line. 
     
     
         12 . Method of filling a reservoir according to  claim 1 , the method comprising:
 connecting the flexible pouch to a liquid additive filling line,   filling the flexible pouch with liquid additive,   measuring a pressure inside the flexible pouch or in the filling line,   diverting all of the liquid additive supplied by the filling line to a purge line when the measured pressure reaches a predetermined threshold value.   
     
     
         13 . Filling method according to  claim 12 , further comprising providing a relief valve between the purge line and the filling line, the relief valve being able to move between a closed position in which the purge line and the filling line are fluidically isolated to allow the flexible pouch to be filled, and an open position in which the purge line and the filling line are fluidically connected, the valve being designed to be moved automatically into the open position when the pressure inside the flexible pouch or in the filling line reaches the predetermined threshold value. 
     
     
         14 . Filling method according to  claim 12 , further comprising purging the flexible pouch before connecting the flexible pouch to the filling line, the purging step preferably being performed using a pump.