Nissan Diesel Motor Co., Ltd.

Hisashi Akagawa

Kiminobu Hirata

Hiroki Ueno

Shuichi Nakamura

Ikuo Sakai

Nobuhiko Masaki

Yuji Yajima

Kouji Masuda

In an exhaust emission purifying apparatus for an internal combustion engine, for adding a reducing agent for NOto the exhaust gas to thereby purify NOin the exhaust gas, the mixing of the reducing agent injected by an injection nozzle with the exhaust gas is accelerated. To this end, in the apparatus of the present invention, the injection nozzle for the urea water is disposed to be opposite to the flow of the exhaust gas, or to face upward in a vertical direction.

Exhaust emission purifying apparatus for internal combustion 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.

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.

A particulate filteris disposed in an exhaust passageof an internal combustion engine, and a reduction catalystis disposed downstream of the particulate filter. A bypass passagefor bypassing the reduction catalystand a flow path switching valvewhich switches a flow path for the exhaust gas which has passed through the particulate filterbetween the exhaust passageand the bypass passageare disposed. A control unitcontrols the flow path switching valvein association with a temperature Texh of the exhaust gas which has passed through the particulate filter

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Ageo, Japan

Hisashi Akagawa