Patent ID: 7752839

Claim:
An exhaust emission purifying apparatus, comprising: a box-shaped casing comprising a compartment wall arranged to partition an inside of the box-shaped casing into a plurality of chambers to form an exhaust passage from an exhaust emission inlet in a first chamber of the plurality of chambers to an exhaust emission outlet in a second chamber of the plurality of chambers, wherein the exhaust passage is folded in direction at least once; a reduction catalyst arranged in the exhaust passage of the box-shaped casing to reductively purify nitrogen oxide in an exhaust emission using a reducing agent; a nozzle arranged in the box-shaped casing to inject the reducing agent or a precursor thereof into the exhaust passage upstream from the reduction catalyst; and a filter arranged in the exhaust passage of the box-shaped casing to collect particulate matter suspended in the exhaust emission, wherein: each of the plurality of chambers forms a respective layered passage of the exhaust passage, the layered passages of the exhaust passage are superposed one on another and adjacent layered passages of the exhaust passage are connected by a folded passage portion of the exhaust passage, the layered passages of the exhaust passage are juxtaposed up and down when the box-shaped casing is mounted in a longitudinal arrangement, the folded passage portion of the exhaust passage has a length substantially corresponding to a height of the box-shaped casing and the nozzle is arranged in an upstream side of the folded passage portion, and the reduction catalyst and the filter are arranged in different respective layered passages of the exhaust passage.