Exhaust emission purifying apparatus for engine

摘要

In order to suppress deposition of constituent of a reducing agent (dissolved matter of the reducing agent) in an exhaust passage of an engine enhancing an elimination rate of NOx even when temperature of an exhaust emission from the engine is low, an exhaust emission purifying apparatus is provided with an electro-generative-heat carrier 11 provided on an upstream side of an injection nozzle 7 that supplies the reducing agent into the exhaust emission on upstream side of a reduction catalyst 5 in an exhaust pipe 3, the exhaust emission in the exhaust pipe 3 being heated to a temperature equal to or higher than a melting point of the dissolved matter of the reducing agent whereby deposition of the dissolved matter of the reducing agent on an inner wall surface of the exhaust pipe 3 is suppressed to effectively use the supplied reducing agent for catalytic reduction reaction, even when the exhaust emission temperature is lower than the melting point of the dissolved matter of the reducing agent. As a result, NOx in the exhaust emission is turned into harmless components enhancing the elimination rate of NOx.