Method and apparatus for isolating inactive fuel passages

Abstract

A system includes a turbine engine having a fuel injector. The fuel injector includes fluid ducts, each having a fuel inlet coupled to a distinct fuel source. The system includes a compressed air source that provides compressed air simultaneously to the fluid ducts, and a convergence point where combined fuel and air streams from the ducts are mixed. The fuel inlets are in a parallel flow arrangement such that no fuel from one fuel injector is present at another fuel injector.

1 . A fluid injector, comprising:
 a first fluid duct having a first active fluid inlet and a second fluid duct having a second active fluid inlet;   a carrier fluid source structured to flow a carrier fluid simultaneously in each of the first fluid duct and the second fluid duct;   a convergence point receiving a first combined stream and a second combined stream, the first combined stream comprising the carrier fluid mixed with a first active fluid and the second combined stream comprising the carrier fluid mixed with a second active fluid; and   wherein the first active fluid inlet and the second active fluid inlet are structured in a parallel flow arrangement.   
     
     
         2 . The fluid injector of  claim 1 , wherein the first active fluid comprises a first fuel and the second active fluid comprises a second fuel. 
     
     
         3 . The fluid injector of  claim 1 , wherein each active fluid comprises a fluid selected from the fluids consisting of: fuel, paint, primer, fluid chemical, solvent, and water. 
     
     
         4 . The fluid injector of  claim 1 , further comprising a third fluid duct having a third active fluid inlet, and wherein the carrier fluid source is further structured to flow the carrier fluid simultaneously in each of the first fluid duct, the second fluid duct, and the third fluid duct. 
     
     
         5 . The fluid injector of  claim 4 , further comprising a third combined stream comprising the carrier fluid mixed with a third active fluid, and wherein the convergence point receives the first combined stream, the second combined stream, and the third combined stream. 
     
     
         6 . The fluid injector of  claim 1 , wherein the parallel flow arrangement comprises each active fluid inlet positioned at a flow location upstream of any fluid mixing point between the first fluid duct and second fluid duct. 
     
     
         7 . The fluid injector of  claim 6 , wherein the parallel flow arrangement comprises each active fluid inlet positioned at a flow location that is an additional distance upstream of any fluid mixing point between the first fluid duct and second fluid duct such that any localized flow reversal will not provide mixed fluid at any active fluid inlet. 
     
     
         8 . The fluid injector of  claim 7 , wherein the localized flow reversal comprises at least one flow selected from the flows consisting of: Coanda effect flow, fluid duct pressure differential flow, and idle active fluid source reverse flow. 
     
     
         9 . The fluid injector of  claim 1 , wherein the carrier fluid comprises a fluid selected from the fluids consisting of: air, nitrogen, argon, an inert gas, water, and a solvent. 
     
     
         10 . A fuel injector, comprising:
 a first fluid duct having a first fuel inlet and a second fluid duct having a second fuel inlet;   a compressed air source structured to flow compressed air simultaneously in each of the first fluid duct and the second fluid duct;   a convergence point receiving a first combined stream and a second combined stream, the first combined stream comprising the compressed air mixed with a first fuel and the second combined stream comprising the compressed air mixed with a second fuel; and   wherein the first fuel source and the second fuel source are structured in a parallel flow arrangement.   
     
     
         11 . The fuel injector of  claim 10 , wherein the parallel flow arrangement comprises each fuel source positioned at a flow location upstream of any fluid mixing point between the first fluid duct and second fluid duct. 
     
     
         12 . The fuel injector of  claim 11 , wherein the parallel flow arrangement comprises each active fuel source positioned at a flow location that is an additional distance upstream of any fluid mixing point between the first fluid duct and second fluid duct such that any localized flow reversal will not provide mixed fluid at any active fluid source. 
     
     
         13 . The fuel injector of  claim 12 , wherein the localized flow reversal comprises at least one flow selected from the flows consisting of: Coanda effect flow, fluid duct pressure differential flow, and idle active fuel source reverse flow. 
     
     
         14 . A system, comprising:
 a turbine engine having a fuel injector, comprising:   a plurality of fluid ducts, each fluid duct coupled to an associated fuel inlet wherein each associated fuel inlet is coupled to a distinct fuel source;   a compressed air source that provides compressed air simultaneously in each of the plurality of fluid ducts;   a convergence point receiving a plurality of combined streams from each of the plurality of fluid ducts, each combined stream comprising compressed air and fuel from the associated fuel inlet; and   wherein the associated fuel inlets are structured in a parallel flow arrangement.   
     
     
         15 . The system of  claim 14 , wherein the parallel flow arrangement comprises each associated fuel inlet positioned at a flow location upstream of any fluid mixing point between each of the plurality of fluid ducts. 
     
     
         16 . The system of  claim 14 , wherein the parallel flow arrangement comprises each associated fuel inlet positioned at a flow location that is an additional distance upstream of any fluid mixing point between each of the plurality of fluid ducts such that any localized flow reversal will not provide mixed fluid at any associated fuel inlet. 
     
     
         17 . The system of  claim 16 , wherein the localized flow reversal comprises at least one flow selected from the flows consisting of: a Coanda effect flow, a fluid duct pressure differential flow, and an idle associated fuel inlet reverse flow. 
     
     
         18 .- 20 . (canceled)