Exhaust emission purifier with additive feeder unit and pressurized air introducer unit

Abstract

An exhaust emission purifier includes a purification unit provided in an exhaust system of an engine for purifying exhaust gases. The exhaust emission purifier also includes an additive feeder unit operatively coupled to the exhaust system at a position between the internal combustion engine and the purification unit for providing an additive to the exhaust gases. Furthermore, the exhaust emission purifier includes a pressurized air introducer unit for receiving air pressurized by an air compressor unit, which is driven by the exhaust gases flowing in the exhaust system and compresses intake air flowing in an intake system of the internal combustion engine. The pressurized air introducer unit is operatively coupled to the additive feeder unit for providing the air pressurized by the air compressor unit to the additive feeder unit.

1 . An exhaust emission purifier, comprising:
 a purification unit provided in an exhaust system of an internal combustion engine for purifying exhaust gases flowing in the exhaust system;   an additive feeder unit operatively coupled to the exhaust system at a position between the internal combustion engine and the purification unit for providing an additive to the exhaust gases flowing in the exhaust system; and   a pressurized air introducer unit for receiving air pressurized by an air compressor unit, which is driven by the exhaust gases flowing in the exhaust system and compresses intake air flowing in an intake system of the internal combustion engine, wherein the pressurized air introducer unit is operatively coupled to the additive feeder unit for providing the air pressurized by the air compressor unit to the additive feeder unit.   
   
   
       2 . An exhaust emission purifier according to  claim 1 , further comprising a check valve that permits flow through the pressurized air introducer unit from the intake system and blocks flow through the pressurized air introducer unit from the additive feeder unit generally toward the intake system. 
   
   
       3 . An exhaust emission purifier according to  claim 1 , wherein the pressurized air introducer unit includes a reservoir provided between the intake system and the additive feeder unit for storing the air pressurized by the air compressor unit. 
   
   
       4 . An exhaust emission purifier according to  claim 1 , wherein the pressurized air introducer unit includes a flow-rate control unit that blocks flow from the intake system to the additive feeder unit when a rate of flow in the pressurized air introducer unit exceeds a predetermined value. 
   
   
       5 . An exhaust emission purifier according to  claim 1 , wherein the air compressor unit is a turbocharger. 
   
   
       6 . An additive feeder for providing an additive to a purification unit of an exhaust system of an internal combustion engine, the additive feeder comprising:
 an additive injection valve operatively coupled to the exhaust system at a position between the internal combustion engine and the purification unit, wherein the additive injection valve injects the additive into exhaust gases flowing in the exhaust system; and   a pressurized air introducer unit for receiving air pressurized by an air compressor unit, which is driven by the exhaust gases flowing in the exhaust system and compresses intake air flowing in an intake system of the internal combustion engine, wherein the pressurized air introducer unit is operatively coupled to the additive injection valve for providing the air pressurized by the air compressor unit to the additive injection valve.   
   
   
       7 . An additive feeder according to  claim 6 , further comprising a check valve that permits flow through the pressurized air introducer unit from the intake system and blocks flow through the pressurized air introducer unit from the additive feeder valve generally toward the intake system. 
   
   
       8 . An additive feeder according to  claim 6 , wherein the pressurized air introducer unit includes a reservoir provided between the intake system and the additive injection valve for storing the air pressurized by the air compressor unit. 
   
   
       9 . An additive feeder according to  claim 6 , wherein the pressurized air introducer unit includes a flow-rate control unit that blocks flow from the intake system to the additive injection valve when a rate of flow in the pressurized air introducer unit exceeds a predetermined value. 
   
   
       10 . An additive feeder according to  claim 6 , wherein the air compressor unit is a turbocharger. 
   
   
       11 . An exhaust purification system for an internal combustion engine, comprising:
 a purification unit provided in an exhaust system of an internal combustion engine for purifying exhaust gases flowing in the exhaust system;   an additive feeder unit operatively coupled to the exhaust system at a position between the internal combustion engine and the purification unit for providing an additive to the exhaust gases flowing in the exhaust system;   an air compressor unit that includes a turbine provided in the exhaust system and driven by the exhaust gases flowing in the exhaust system, the air compressor unit further including a compressor provided in an intake system of the internal combustion engine and driven by the turbine, wherein the compressor pressurizes intake air flowing in the intake system; and   a pressurized air introducer unit for receiving air pressurized by the air compressor unit and is operatively coupled to the additive feeder unit for providing the air pressurized by the air compressor unit to the additive feeder unit.   
   
   
       12 . An exhaust purification system for an internal combustion engine according to  claim 11 , further comprising a check valve that permits flow through the pressurized air introducer unit from the intake system and blocks flow through the pressurized air introducer unit from the additive feeder unit generally toward the intake system. 
   
   
       13 . An exhaust purification system for an internal combustion engine according to  claim 11 , wherein the pressurized air introducer unit includes a reservoir provided between the intake system and the additive feeder unit for storing the air pressurized by the air compressor unit. 
   
   
       14 . An exhaust purification system for an internal combustion engine according to  claim 11 , wherein the pressurized air introducer unit includes a flow-rate control unit that blocks flow from the intake system to the additive feeder unit when a rate of flow in the pressurized air introducer unit exceeds a predetermined value. 
   
   
       15 . An exhaust purification system according to  claim 11 , wherein the air compressor unit is a turbocharger.