Apparatus for maintening a urea solution in a liquid state for treatment of diesel exhaust

摘要

A system for keeping a reservoir solution of urea in a liquid state at normally sub-freezing temperatures comprising a reservoir tank module disposed in a solution storage tank (118). Solution in the storage tank (118) is heated partially by passage of heat through the walls of the reservoir tank module. Additional heat is derived from waste heat in engine exhaust gas and is added to the system either by passing a portion of the exhaust gas stream directly onto or through the solution or by passing air heated by the exhaust gas stream directly onto or through the solution. Alternatively, the hot gas may be impinged onto an outer surface of the storage tank (118).