Patent ID: 7895828
Filing Date: 2011-03-01
Classification: B01D,B01F,B05B,F01N,Y02T

Abstract:
1. A liquid reducing agent injection nozzle having a novel structure, and provided with such a configuration that the liquid reducing agent injection nozzle is: attached to a wall surface of an exhaust flow passage of an exhaust gas located on an upstream of a reduction catalyst in the exhaust flow passage, the reduction catalyst being operative to reduce and purify a nitrogen oxide using a liquid reducing agent and disposed in the exhaust flow passage; arranged to protrude from the wall surface towards a passage center to a position close to but before the passage center; and configured to permit the liquid reducing agent to be spouted and supplied from a number of nozzle holes formed therein around a nozzle tip end portion thereof, the nozzle tip end portion being bent to have a posture thereof which is directed substantially toward a direction of flow of the exhaust gas, wherein the bent nozzle tip end portion of the liquid reducing agent injection nozzle is arranged to have a central axis thereof directed towards the passage center and defining an angle of bend which is oblique to the flow of exhaust gas in the exhaust flow passage, and wherein the number of nozzle holes of the nozzle tip end portion are unevenly distributed in a circumferential direction of the nozzle tip end portion excluding a surrounding area which faces the wall surface on the nozzle attaching side of the bent nozzle tip end portion, so that the liquid reducing agent is not spouted to a wall surface portion of the exhaust flow passage including a predetermined range that includes a nozzle attaching portion of the wall surface on the nozzle attaching side as a substantially center position thereof, and the liquid reducing agent is spouted to a wall surface portion of the exhaust flow passage excluding the predetermined range, viewing from a cross-sectional direction of the exhaust flow passage.