Injection device for the treatment of exhaust fumes from motor vehicles

Abstract

A device for injecting at intermittent periods a dispersion of a liquid at controlled pulsing periods into exhaust fumes of a combustion engine, said liquid contains a component which reacts with a component of the exhaust fumes at a catalytic converter, said device comprises a housing containing a first chamber a means for supplying the liquid into a first chamber a means for pumping the liquid from the first chamber into a pressure swirl atomizer where the liquid is dispersed, said swirl atomizer comprising an outlet nozzle leading the dispersion into an exhaust manifold through which the exhaust fumes are directed prior to being converted at the catalytic converter, said device further comprises a means for controlling the means for pumping such that a pulsing period during which the liquid is injected into the swirl atomizer is controlled to be from about 1 to about 1000 milliseconds as well as a method for injecting a dispersion of a liquid into exhaust fumes of combustion engines.

1 . A device for injecting at intermittent, controlled pulsing periods, a dispersion of a liquid into exhaust fumes of a combustion engine, the liquid containing a component which reacts with a component of the exhaust fumes at a catalytic converter, said device comprises: 
 a housing;    a first chamber;    a means for supplying the liquid into said first chamber;    a means for pumping the liquid from said first chamber into a pressure swirl atomizer where the liquid is dispersed, the atomizer from which the dispersion is fed into an exhaust manifold through which the exhaust fumes are directed prior to being converted at the catalytic converter; and    a means for controlling said means for pumping such that a pulsing period during which the liquid is injected into the swirl atomizer is controlled to be from about 1 to about 1000 milliseconds.    
     
     
         2 . The device of  claim 1 , wherein the pulsing period is from about 10 to about 1100 milliseconds.  
     
     
         3 . The device of  claim 1 , wherein during the pulsing period, from about 0.1 to about 5 mg liquid is dispersed per millisecond.  
     
     
         4 . The device of  claim 1 , wherein during the pulsing period, from about 0.5 to about 1.5 mg liquid is dispersed per millisecond.  
     
     
         5 . The device of  claim 1 , wherein the liquid is dispersed in an amount of from about 0.1 to about 1.5 mg per millisecond.  
     
     
         6 . The device of  claim 1 , wherein the pressure swirl atomizer is connected to said first chamber via an adapter plate.  
     
     
         7 . The device of  claim 1 , wherein the liquid is fed into the pressure swirl atomizer at a pressure of from about 1.2 to about 6 bar.  
     
     
         8 . The device of  claim 1 , wherein the liquid is fed into the pressure swirl atomizer at a pressure of from about 1.2 to about 5 bar.  
     
     
         9 . A device for injecting at intermittent periods a dispersion of a liquid at controlled pulsing periods into exhaust fumes of a combustion engine, the liquid contains a component which reacts wit a component of the exhaust fumes at a catalytic converter, said device comprises: 
 a housing;    a first chambers    a means for supplying the liquid into said first chamber;    a means for pumping the liquid from said first chamber into a pressure swirl atomizer where the liquid is dispersed, the swirl atomizer comprising an outlet nozzle leading the dispersion into an exhaust manifold through which the exhaust fumes are directed prior to being converted at the catalytic converter; and    a means for controlling said means for pumping such a pulsing period during which the dispersion is injected into exhaust fumes is from about 1 to about 1000 milliseconds.    
     
     
         10 . The device of  claim 9  wherein the pulsing period is from about 10 to about 100 milliseconds.  
     
     
         11 . The device of  claim 9 , wherein during a pulsing period from about 0.1 to about 5 mg liquid is dispersed per millisecond.  
     
     
         12 . The device of  claim 9 , wherein during a pulsing period from about 0.5 to about 1,5 mg liquid is dispersed per millisecond.  
     
     
         13 . The device of  claim 9 , wherein the liquid is dispersed in an amount of from about 0.1 to about 1.5 mg per millisecond.  
     
     
         14 . The device of  claim 9 , wherein the pressure swirl atomizer is connected to said first chamber via an adapter plate.  
     
     
         15 . The device of  claim 9 , wherein the liquid is fed into the pressure swirl atomizer at a pressure of from about 1.2 to about 6 bar.  
     
     
         16 . The device of  claim 9 , wherein the liquid is fed into the pressure swirl atomizer at a pressure of about 1.2 to about 5 bar.  
     
     
         17 . A method of injecting a dispersed liquid into exhaust fumes of a combustion engine during intermittent pulse periods, said method comprising the step of pumping a solution at controlled pulse periods through a pressure swirl atomizer, wherein the pulse periods are from about 1 to about 1000 milliseconds.  
     
     
         18 . The method of  claim 17 , wherein the liquid is an aqueous urea solution.  
     
     
         19 . The method of  claim 17 , wherein the liquid is an aqueous solution and wherein from about 0.1 to about 5 mg/millisecond of the solution is pumped through the pressure swirl atomizer during a pulse period.  
     
     
         20 . The method of  claim 17 , wherein the liquid is an aqueous solution and wherein from about 0.1 to about 1 mg/millisecond of the solution is pumped through the pressure swirl atomizer during a pulse period.  
     
     
         21 . A method of reducing the levels of nitrogen oxides in exhaust fumes of combustion engines in motor vehicles, comprising the steps of. 
 leading the exhaust fumes over a selective catalytic reduction converter which converts the nitrogen oxides in the presence of at least another reactive component into components that are less toxic to humans than nitrogen oxides,    wherein the other reactive component is added as a dispersion of a solution containing the reactive component;    forming a dispersion by pumping the solution containing the reactive component at controlled amounts and during controlled pulse periods into a pressure swirl atomizer and directing the dispersion into the stream of exhaust fumes before it contacts the catalytic converter.    
     
     
         22 . The method of  claim 21 , wherein the amount of liquid pumped into the pressure swirl atomizer is from about 0.1 to about 5 mg per millisecond of the pulse period.  
     
     
         23 . The method of  claim 21  wherein the amount of liquid pumped into the pressure swirl atomizer is from about 0.5 to about 1.5 mg per millisecond of the pulse period.  
     
     
         24 . The method of  claim 21 , wherein the pulse period is from about 1 to about 1000 milliseconds.  
     
     
         25 . The method of  claim 21 , wherein liquid is pumped into the pressure swirl atomizer at an operating pressure of from about 1.2 to about 6 bar.