Patent ID: 7765793
Filing Date: 2010-08-03
Classification: B01D,F01N,F02B,F02D,F02M,Y02T

Abstract:
1. An exhaust emission control device of an internal combustion engine, comprising: a variable-geometry turbocharger including a supercharger for supercharging the internal combustion engine; a NOx reducing catalyst provided in an exhaust gas passage of the internal combustion engine; a reducing agent sprayer for spraying a reducing agent to the NOx reducing catalyst using supercharged air at a supercharging pressure from a side of the supercharger of the variable geometry turbocharger; a load detector for detecting a load applied on the internal combustion engine; an opening degree controller for controlling the super-charging pressure to atomize the reducing agent by controlling a nozzle opening degree of the variable geometry turbocharger based on the load applied on the internal combustion engine that is detected by the load detector, wherein the opening degree controller controls the nozzle opening degree so that the supercharging pressure is at or above a predetermined value at which the reducing agent is atomized, when the load detected by the load detector is in a low load range equal to or higher than a reference load at which the catalyst starts functioning; wherein the opening degree controller controls the nozzle opening degree without consideration of atomization of the reducing agent, when the load detected by the load detector exceeds the low load range; and wherein the reducing agent sprayer is arranged to receive a controllable flow of supercharged air from the supercharger of the variable geometry turbocharger and the reducing agent separate from one another, and ejects the supercharged air and reducing agent in order to cause the atomization of the reducing agent with the atomized reducing agent being sprayed directly into the exhaust gas passage.