Reductant supply system

Abstract

An aftertreatment system is disclosed. The aftertreatment system includes an exhaust conduit and a selective catalytic reduction module. The aftertreatment system also includes a reductant supply system. The reductant supply system includes a reductant tank, a reductant injector, and a pump assembly. The pump assembly includes a reversing valve assembly and a pump unit. The pump assembly also includes a plurality of check valves, a pressure sensor, and a filter. Further, the reductant supply system includes a back flow valve assembly. The reductant supply system also includes at least two header units associated with the pump assembly. The at least two header units include a reductant draw conduit and at least one heat exchanger. The at least two header units also include a bag filtration assembly.

What is claimed is: 
     
         1 . An aftertreatment system comprising:
 an exhaust conduit;   a selective catalytic reduction module configured to receive an exhaust gas flow from the exhaust conduit; and   a reductant supply system configured to supply a reductant into the exhaust conduit upstream of the selective catalytic reduction module, the reductant supply system comprising:
 a reductant tank; 
 a reductant injector; 
 a pump assembly in fluid communication with the reductant tank and the reductant injector, the pump assembly comprising:
 a reversing valve assembly; 
 a pump unit; 
 a plurality of check valves associated with the pump unit; 
 a pressure sensor; and 
 a filter; 
 
 a back flow valve assembly in fluid communication with the pump assembly and the reductant tank; 
 at least two header units associated with the pump assembly, each of the at least two header units comprising:
 a reductant draw conduit configured to supply the reductant from the reductant tank to the pump assembly; and 
 at least one heat exchanger; and 
 
 a bag filtration assembly provided on each of the at least two header units.