Anti-clogging device for diesel exhaust fluid supply

Abstract

An apparatus for supplying Diesel Exhaust Fluid to an engine exhaust gas treatment system includes a reservoir to collect trapped air if the dosing module is clogged with crystalized urea. The reservoir is placed at the dosing valve inlet on a T-connection. The reservoir provides a closed chamber to receive trapped air in the DEF supply line, allowing DEF to flow to the dosing module. When DEF contacts the crystallized urea causing the clog, the urea dissolves, freeing the injector so that normal action of the dosing module is restored.

1 . An apparatus for delivering aqueous urea fluid into an exhaust gas system of a combustion engine, comprising:
 a dosing module mountable on an engine exhaust conduit and configured to deliver aqueous urea fluid to the exhaust conduit;   a feed line connected to carry aqueous urea fluid to an inlet of the dosing module; and,   a reservoir for collecting air trapped in the feed line connected to the feed line at the inlet of the dosing module, wherein the feed line includes a branch at the inlet of the dosing module, the reservoir connected to the branch.   
     
     
         2 . The apparatus of  claim 1 , comprising a pump connected on the feed line to deliver aqueous urea fluid to the feed line. 
     
     
         3 . The apparatus of  claim 2 , comprising an aqueous urea fluid supply tank and a supply line connecting the supply tank to the pump. 
     
     
         4 . The apparatus of  claim 1 , wherein the reservoir is vertically above the dosing module. 
     
     
         5 . An apparatus for delivering aqueous urea fluid to an exhaust gas system of a combustion engine, comprising:
 a supply tank  10  for storing aqueous urea fluid;   a pump  20  having an inlet and an outlet, the inlet connected by a supply line to the supply tank;   a dosing module  30 ;   a feed line  24  connecting the pump outlet  26  to the dosing module, the feed line having a T-connector at the dosing module, the T connector  40  having an inlet  42  to receive DEF from the pump  20 , a first outlet  44  to deliver DEF to the dosing module  30 , and a second outlet  46 ;   a reservoir  50  connected to the second outlet to collect air trapped at an inlet of the dosing module.   
     
     
         6 . The apparatus of  claim 5 , wherein the reservoir  50  is a closed chamber having a single opening, the single opening connected at the second outlet. 
     
     
         7 . An apparatus for delivering aqueous urea fluid into an exhaust gas system of a combustion engine, comprising:
 a dosing module mountable on an engine exhaust conduit and configured to deliver aqueous urea fluid to the exhaust conduit;   a pump to deliver aqueous urea fluid to the dosing module;   a feed line having a first end connected to an outlet of the pump and a second end having two branches, a first branch connected to an inlet of the dosing module; and,   a reservoir on the second branch of the feed line, the reservoir for collecting air trapped in the feed line.   
     
     
         8 . The apparatus of  claim 7 , wherein the reservoir is a closed chamber having a single opening.