Apparatus for Directing Exhaust Flow through a Fuel-Fired Burner of an Emission Abatement Assembly

Abstract

An emission abatement assembly includes a fuel-fired burner having a housing and a combustion chamber positioned within the housing. The combustion chamber includes a wall circumscribing a space. The emission abatement assembly further includes an exhaust gas inlet pipe having an elbow at an outlet end positioned within the housing. The elbow is positioned to direct an entire flow of exhaust gas in a direction toward an interior wall of the housing such that the entire flow of exhaust gas exiting the elbow impinges upon the interior wall prior to reaching the wall and space of the combustion chamber.

1 . An emission abatement assembly comprising:
 a fuel-fired burner having a housing and a combustion chamber positioned within the housing, the combustion chamber comprising a wall circumscribing a space configured to hold a burner flame, and   an exhaust gas inlet pipe having an elbow at an outlet end positioned within the housing, the elbow being positioned to direct an entire flow of exhaust gas in a direction toward an interior wall of the housing such that the entire flow of exhaust gas exiting the elbow impinges upon the interior wall prior to reaching the wall and space of the combustion chamber.   
   
   
       2 . The emission abatement assembly of  claim 1 , wherein the entire flow of exhaust gas is induced to flow in a swirling pattern within the housing after impinging upon the interior wall. 
   
   
       3 . The emission abatement assembly of  claim 2 , wherein a portion of the entire flow of exhaust gas enters the space of the combustion chamber through gas inlet openings disposed through the wall of the combustion chamber. 
   
   
       4 . An emission abatement assembly comprising:
 a particulate filter, and   a fuel-fired burner positioned upstream of the particulate filter, the fuel-fired burner comprising:
 (i) a housing, 
 (ii) a combustion chamber having a shroud secured thereto, the combustion chamber and the shroud cooperate to separate an entire flow of exhaust gas entering the housing into (a) a combustion flow which is advanced through the combustion chamber of the fuel-fired burner, and (b) a bypass flow which is bypassed around the combustion chamber of the fuel-fired burner, 
 (iii) an exhaust gas inlet pipe extending into the housing, the exhaust gas inlet pipe having an elbow at an outlet end positioned within the housing, the elbow being positioned to direct the entire flow of exhaust gas entering the housing in a direction toward an interior wall of the housing such that exhaust gas exiting the elbow impinges upon the interior wall prior to reaching the combustion chamber and the shroud, and 
 (iv) a mixing baffle positioned downstream of the combustion chamber and upstream of the particulate filter, the mixing baffle being configured to mix the combustion flow and the bypass flow. 
   
   
   
       5 . The emission abatement assembly of  claim 4 , wherein:
 the mixing baffle comprises a collector plate having a hole defined therein, and   a diverter plate positioned downstream of the hole.   
   
   
       6 . The emission abatement assembly of  claim 5 , wherein:
 the mixing baffle further comprises a perforated ring surrounding the hole,   a first end of the perforated ring is secured to the collector plate, and   a second end of the perforated ring is secured to the diverter plate.   
   
   
       7 . The emission abatement assembly of  claim 6 , wherein the mixing baffle is configured such that the combustion flow and bypass flow are at least partially mixed when said flows are directed radially outwardly through the perforated ring by contact with the diverter plate. 
   
   
       8 . The emission abatement assembly of  claim 5 , wherein the diverter plate is domed. 
   
   
       9 . An emission abatement assembly, comprising:
 a fuel-fired burner having a housing and a combustion chamber positioned within the housing, and   an exhaust gas inlet pipe having an elbow at an outlet end positioned within the housing, the elbow being positioned to direct exhaust gas in a direction toward an interior wall of the housing to impinge upon the interior wall to induce a swirling flow pattern in the exhaust gas exiting the elbow prior to reaching the combustion chamber.   
   
   
       10 . The emission abatement assembly of  claim 9 , wherein a portion of the exhaust gas enters gas inlet openings of the combustion chamber. 
   
   
       11 . The emission abatement assembly of  claim 10 , wherein:
 the combustion chamber comprises a wall having the gas inlet openings disposed therein, the wall circumscribing a space configured to hold a burner flame, and   the portion of the exhaust gas enters the space of the combustion chamber through gas inlet openings disposed through the wall of the combustion chamber.