Overfire air system improves biomass stoker boiler operation

A new OFA (overfire air) system was installed on a co-fired stoker coal/bagasse boiler in a Colombian pulp and paper mill. The main objectives were to reduce particulate emissions and increase thermal efficiency. Preliminary results indicate that these improvements in boiler efficiency have been achieved. Emissions compliance testing has not yet been carried out, but stack opacity is reduced. The apparent increased efficiency has enabled firing of more biomass to displace coal, another aim of the project.