System for separating liquid exhaust reductant from a mixing conduit wall using flow separation elements

Abstract

An exhaust treatment system for a work vehicle includes a reductant injector configured to inject an exhaust reductant into the engine exhaust flow flowing through a mixing conduit. A plurality of flow separation elements are located downstream of the reductant injector and are configured to separate a liquid reductant flow from an inner conduit wall of the mixing conduit for mixing with the engine exhaust flow flowing therein.

What is claimed: 
     
         1 . An exhaust treatment system for a work vehicle, the system rising:
 an exhaust conduit configured to receive an engine exhaust flow;   a reductant injector configured to inject an exhaust reductant into the engine exhaust flow;   a mixing conduit extending lengthwise between an upstream end and a downstream end, the mixing conduit including an inner conduit wall defining a flow area through which the engine exhaust flow and the exhaust reductant injected are directed between the upstream and downstream ends of the mixing conduit to allow the exhaust reductant to be at least partially mixed into the engine exhaust flow, a portion of the exhaust reductant flowing along the inner conduit wall of the mixing conduit as a liquid reductant flow; and   a plurality of flow separation elements provided in operative association with the inner conduit wall of the mixing conduit, the plurality of flow separation elements configured to separate the liquid reductant flow from the inner conduit wall as the liquid reductant flow is directed across the plurality of flow separation elements.   
     
     
         2 . The system of  claim 1 , wherein the liquid reductant flow is initiated along the inner conduit wall at a location at or downstream of a reductant attachment location disposed between the upstream and downstream ends of the mixing conduit, the plurality flow separation elements being positioned within the mixing conduit downstream of the reductant attachment location. 
     
     
         3 . The system of  claim 1 , further comprising a mixer positioned within the mixing conduit between the upstream end of the mixing conduit and the plurality of flow separation elements. 
     
     
         4 . The system of  claim 1 , wherein the plurality of flow separation elements comprise a plurality of radially inwardly extending protrusions. 
     
     
         5 . The system of  claim 1 , wherein the plurality of flow separation elements comprise a plurality of radially outwardly extending indentions formed in the inner conduit wall. 
     
     
         6 . The system of  claim 1 , wherein the plurality of flow separation elements are disposed in an annular array around the inner conduit wall of the mixing conduit. 
     
     
         7 . The system of  claim 1 , wherein the plurality of flow separation elements are circumferentially offset from one another. 
     
     
         8 . The system of  claim 1 , wherein the plurality of flow separation elements are axially staggered relative to one another along a length of the mixing conduit. 
     
     
         9 . The system of  claim 1 , wherein the plurality of flow separation elements are axially staggered and circumferentially aligned relative to one another. 
     
     
         10 . The system of  claim 1 , further comprising a selective catalytic reduction (SCR) system configured to receive the mixture of exhaust reductant and engine exhaust flow directed from the downstream end of the mixing conduit. 
     
     
         11 . A work vehicle, comprising:
 an engine expelling an engine exhaust flow;   an exhaust conduit configured to receive the engine exhaust flow the engine;   a reductant injector configured to inject an exhaust reductant into the engine exhaust flow;   a mixing conduit extending lengthwise between an upstream end and a downstream end, the mixing conduit including an inner conduit wall defining a flow area through which the engine exhaust flow and the exhaust reductant are directed between the upstream and downstream ends of the mixing conduit to allow the exhaust reductant to be at least partially mixed into the engine exhaust flow, a portion of the exhaust reductant flowing along the inner conduit wall of the mixing conduit as a liquid reductant flow; and   a plurality of flow separation elements provided in operative association with the inner conduit wall of the mixing conduit, the plurality of flow separation elements configured to separate the liquid reductant flow from the inner conduit wall as the liquid reductant flow is directed across the plurality of flow separation elements.   
     
     
         12 . The work vehicle of  claim 12 , wherein the liquid reductant flow is initiated along the inner conduit wall at a location at or downstream of a reductant attachment location disposed between the upstream and downstream ends of the mixing conduit, the plurality flow separation elements being positioned within the mixing conduit downstream of the reductant attachment location. 
     
     
         13 . The work vehicle of  claim 12 , further comprising a mixer positioned within the mixing conduit between the upstream end of the mixing conduit and the plurality of flow separation elements. 
     
     
         14 . The work vehicle of  claim 12 , wherein the plurality of flow separation elements comprise a plurality of radially inwardly extending protrusions. 
     
     
         15 . The work vehicle of  claim 12 , wherein the plurality of flow separation elements comprise a plurality of radially outwardly extending indentions formed in the inner conduit wall. 
     
     
         16 . The work vehicle of  claim 12 , wherein the plurality of flow separation elements are disposed in an annular array around the inner conduit wall of the mixing conduit. 
     
     
         17 . The work vehicle of  claim 12 , wherein the plurality of flow separation elements are circumferentially offset from one another. 
     
     
         18 . The work vehicle of  claim 12 , wherein the plurality of flow separation elements are axially staggered relative to one another along a length of the mixing conduit. 
     
     
         19 . The work vehicle of  claim 12 , wherein the plurality of flow separation elements are axially staggered and circumferentially aligned relative to one another. 
     
     
         20 . The work vehicle of  claim 12 , further comprising a selective catalytic reduction (SCR) system configured to receive the mixture of exhaust reductant and engine exhaust flow directed from the downstream end of the mixing conduit.