EXHAUST GAS PURIFICATION DEVICE

摘要

An exhaust gas purification device where occurrence of detection failure of injection nozzle clogging is suppressed. An exhaust gas purification device for an engine, having a reduction catalyst (4) provided in the exhaust system of the engine (1) and reducing and purifying a nitrogen oxide in exhaust gas by a urea water, a urea water tank (6) storing the urea water, a urea water supply means (7) for sucking up the urea water and sending it out after mixing it with high-pressure air, and an injection nozzle (5) for injecting the urea water, mixed with the high-pressure air, inside an exhaust pipe (3) of the exhaust gas system, to the exhaust gas upstream side of the reduction catalyst (4). The exhaust gas purification device further has a clogging detection means (8) for detecting clogging of the injection nozzle based on a detection output on the pressure of air introduced into the urea water supply means (7) and a detection output on the temperature of the injection nozzle (5).