Aftertreatment burner air supply system

Abstract

A system and method for efficient regeneration of a diesel particulate filter used in the exhaust system of a diesel engine, is disclosed. In various systems, a burner is incorporated into the exhaust stream, and prior to the diesel particulate filter. Because the burner requires precise amounts of fuel and air to operate properly, an air flow delivery device, such as a positive displacement pump or blower is incorporated into the system to channel boost air to the burner. Alternatively, a bypass line may be used in conjunction with a pressure regulator, wherein the bypass line diverts the boost air from the pump or blower, while the pressure regulator controls the final pressure to the burner.

What is claimed is: 
     
         1 . A system for regenerating a diesel particulate filter, the system comprising:
 an exhaust system for a diesel engine having a fresh air intake and an exhaust gas output;   a burner fluidly connected to the exhaust gas output;   a feed line connected to the air intake and the burner;   a positive displacement pump positioned within the feed line;   an air flow regulating valve fluidly connected within the feed line for controlling the air flow from the air intake to the burner; and,   the particulate filter fluidly connected in the exhaust gas output after the burner.   
     
     
         2 . The system of  claim 1 , wherein the fresh air intake provides air to the exhaust system and the feed line. 
     
     
         3 . The system of  claim 2 , wherein the fresh air intake provides an unregulated boost air stream to the positive displacement pump. 
     
     
         4 . The system of  claim 1 , wherein the positive displacement pump is positioned before the air flow regulating valve within the feed line. 
     
     
         5 . The system of  claim 4 , wherein the pump delivers a pre-determined air flow to the burner. 
     
     
         6 . The system of  claim 1 , wherein the air flow regulating valve is a check valve. 
     
     
         7 . The system of  claim 1 , wherein the system further includes a three-way regulating valve positioned within the feed line, the valve having an inlet and a first and second outlet. 
     
     
         8 . The system of  claim 7 , wherein the system further includes a bypass line fluidly connected to the first outlet of the three-way regulating valve. 
     
     
         9 . The system of  claim 7 , wherein the pump is connected within the feed line to the second outlet of the three-way regulating valve. 
     
     
         10 . The system of  claim 9 , wherein the bypass line diverts air flow around the pump to the air flow regulating valve and the burner. 
     
     
         11 . The system of  claim 1 , wherein the system further includes a pressure regulator positioned within the feed line before the burner. 
     
     
         12 . A system for regenerating a diesel particulate filter, the system comprising:
 an exhaust system for a diesel engine having a fresh air intake and an exhaust gas output;   a burner fluidly connected to the exhaust gas output;   a feed line connected to the air intake and the burner;   a three-way regulating valve having an inlet and a first and second outlet, wherein the inlet and outlets are fluidly connected to the feed line;   an air flow delivery device positioned within the feed line at the first outlet of the regulating valve;   a bypass line positioned within the feed line at the second outlet of the regulating valve;   a pressure regulator fluidly connected within the feed line for controlling the air flow from one of the bypass line and the air flow device to the burner; and,   the particulate filter fluidly connected in the exhaust gas output after the burner.   
     
     
         13 . A system for regenerating a diesel particulate filter, the system comprising:
 an exhaust system for a diesel engine having a fresh air intake connected through a turbocharger compressor, and an exhaust gas output;   a burner fluidly connected to the exhaust gas output;   a first feed line connected to directly to the air intake;   an air flow delivery device within the first feed line;   a first air flow regulating valve fluidly connected within the first feed line for controlling the air flow from the air intake to the positive displacement pump to the burner;   a second feed line connected to the air intake after the turbocharger compressor;   a second air flow regulating valve fluidly connected within the second feed line for controlling the air flow from the air intake to a pressure regulator and the burner; and,   the particulate filter fluidly connected in the exhaust gas output after the burner.   
     
     
         14 . The system of  claim 13 , wherein the system further includes an electronic control module for activating either one of the first air flow valve and the second air flow valve for delivering a pre-determined air flow to the burner. 
     
     
         15 . The system of  claim 13 , wherein the system further includes a pressure regulator positioned before the burner. 
     
     
         16 . The system of  claim 13 , wherein the air flow delivery device is one of a positive displacement pump and a blower. 
     
     
         17 . A method for regenerating a diesel engine particulate filter, the method comprising the steps of:
 providing an exhaust system for a diesel engine having a fresh air intake stream and an exhaust gas output stream;   channeling a portion of the exhaust gas output stream toward a burner connected to the particulate filter;   delivering a pre-determined volume of boost air from the fresh air intake stream to the burner;   maintaining a pre-determined regeneration temperature of the exhaust gas output stream from the burner to the particulate filter; and,   regenerating the particulate filter.   
     
     
         18 . The method of  claim 17 , wherein the step of delivering the volume of boost air includes delivery through a feed line connecting the fresh air intake stream to the burner. 
     
     
         19 . The method of  claim 18 , wherein the step of delivering the volume of boost air further includes adding at least one air flow regulating valve to the feed line. 
     
     
         20 . The method of  claim 17 , wherein the step of regulating the pressure of the booster air to the burner includes providing an air flow delivery device within the feed line. 
     
     
         21 . The method of  claim 20 , wherein the step of regulating the pressure of the booster air includes providing a pressure regulator between the burner and the air flow delivery device. 
     
     
         22 . The method of  claim 17 , wherein the step of regulating the pressure of the booster air to the burner includes providing a pressure increasing device. 
     
     
         23 . The method of  claim 22 , wherein the pressure increasing device includes a blower. 
     
     
         24 . A system for regenerating a diesel particulate filter, the system comprising:
 an exhaust system for a diesel engine having a fresh air intake and an exhaust gas output;   a burner fluidly connected to the exhaust gas output;   a feed line connected to the air intake and the burner;   a means for delivering a pre-determined amount of air from the fresh air intake into the feed line;   an air flow regulating valve fluidly connected within the feed line for controlling the air flow from the air intake to the burner; and,   the particulate filter fluidly connected in the exhaust gas output after the burner.   
     
     
         25 . The system of  claim 24 , wherein the means for delivering the pre-determined amount of air includes a positive displacement pump. 
     
     
         26 . The system of  claim 24 , wherein the means for delivering the pre-determined amount of air includes a pressure increasing blower.