Low temperature Nox/Sox removal apparatus

摘要

Exhaust gases from a process fired boiler are diverted from a stack prior to emission to the atmosphere through a duct system to a plurality of series connected heat exchangers. The exhaust gases are progressively reduced from an elevated temperature, for example in the range between about 350 DEG -525 DEG F., in stages to an ambient temperature of about 50 DEG F. At each stage heat from the exhaust gases is transferred from the gases to another medium, such as water, which is fed back to the boiler to reduce the energy cost of operating the boiler. At ambient temperature the exhaust gases are subjected to an atomized spray of a reagent solution that absorbs the contaminants in the exhaust gases. Absorption of the contaminants into solution with the atomized reagent spray is promoted by contact of the spray and exhaust gases on the surface of a fibrous batting. With the exhaust gases at ambient temperature the percentage of contaminants in the flue gas that enters into solution with the reagent is substantially increased. Thus the reagent absorbs the contaminants, and the exhaust gases are emitted after further moisture separation substantially free of contaminants.