Patent ID: 8024922
Filing Date: 2011-09-27
Classification: F01N,Y02A,Y02T,Y10T

Abstract:
1. A reductant delivery unit for selective catalytic reduction (SCR) after-treatment for vehicles, the reductant delivery unit comprising: a solenoid fluid injector constructed and arranged to be associated with an exhaust gas flow path upstream of a SCR catalytic converter, the fluid injector having a fluid inlet and a fluid outlet and a coil, the fluid inlet being constructed and arranged to receive a source of urea solution and the fluid outlet being constructed and arranged to communicate directly with the exhaust flow path so as to control injection of urea solution into the exhaust gas flow path, an interface constructed and arranged to couple the fluid injector to the gas flow path, the interface defining a thermal barrier constructed and arranged to decoupled a body of the injector from exposure to heat in the exhaust gas flow path, and a controller constructed and arranged to determine whether urea solution in the injector is frozen and if the urea solution is determined to be frozen, the controller is constructed and arranged to actuate the coil thereby delivering electrically generated heat to the fluid injector to melt the urea solution.