Nissan Diesel Motor Co., Ltd.

Ikuo Sakai

Kiminobu Hirata

Hiroki Ueno

Hisashi Akagawa

Shuichi Nakamura

Kouji Masuda

An engine exhaust emission purification apparatus for reducing and purifying NOx in the exhaust emission by using a liquid reducing agent having a temperature maintenance device for maintaining a temperature of at least a part of a liquid reducing agent supply system configured by an injection nozzle and piping of the injection nozzle at a temperature lower than a boiling point of a solvent of the liquid reducing agent or equal to or higher than a melting point of dissolved matter in which the liquid reducing agent existing in the liquid reducing agent supply system conducts heat exchange with the liquid reducing agent supply system thereby being maintained at a temperature lower than the boiling point of the solvent or equal to or higher than the melting point of the dissolved matter and resultantly, occurrence of precipitation of the dissolved matter due to evaporation of only the solvent in the liquid reducing agent supply system does not occur, and even if precipitation of the dissolved matter occurs, the dissolved matter per se is melt away to prevent an injection hole of the injection nozzle from being clogged.

Engine exhaust emission purification apparatus

A NOreduction catalyst and an ammonia slip oxidation catalyst are disposed in an exhaust system in this order, and also, an electric fan is disposed on piping which communicates an upper space of a storage tank storing therein a reducing agent with the exhaust upstream of the NOreduction catalyst. Then, when the temperature of the ammonia slip oxidation catalyst reaches or exceeds the temperature for activating a catalyst thereof, the electric fan is operated for a predetermined period of time, so that the gas (ammonia series gas) in the upper space of the storage tank is forcibly discharged to the upstream side of the NOreduction catalyst. Further, a discharge-forcing device, such as an electric fan or the like, forcibly discharging the gas in the upper space of the storage tank, an adsorbing device temporarily adsorbing thereto the forcibly discharged gas and an oxidation catalyst oxidizing the gas desorbed from the adsorbing device, may be disposed to the storage tank in this order.

Exhaust emission purifying apparatus for engine

An engine exhaust emission purification apparatus for reducing and purifying NOx in the exhaust emission by using a liquid reducing agent having a temperature maintenance device for maintaining a temperature of at least a part of a liquid reducing agent supply system configured by an injection nozzle and piping of the injection nozzle at a temperature lower than a boiling point of a solvent of the liquid reducing agent or equal to or higher than a melting point of dissolved matter in which the liquid reducing agent existing in the liquid reducing agent supply system conducts heat exchange with the liquid reducing agent supply system thereby being maintained at a temperature lower than the boiling point of the solvent or equal to or higher than the melting point of the dissolved matter and resultantly, occurrence of precipitation of the dissolved matter due to evaporation of only the solvent in the liquid reducing agent supply system does not occur, and even If precipitation of the dissolved matter occurs, the dissolved matter per se is melt away to prevent an injection hole of the injection nozzle from being clogged.

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Ageo, Japan

Ikuo Sakai