Ash Volume Reduction and Boiler Efficiency Improvement by Ash Reburning, 1992 Engineering Conference Proceedings

The ash reburn system, described in this paper, was developed in response to a growing wood burning industry need for reduction of ash volume and more efficient carbon burnout on existing wood fired boilers. Experience in wood and fuel burning, coupled with Customer feedback, indicated that on older boiler designs improvements in traditional ash reinjection and/or overfire air systems would not yield the significant improvements that are now desired. Consequently a system was developed that utilizes an external ash reburn cell run in parallel with the existing stoker. The heat generated from the reburn cell is in-turn recovered in the existing boiler.

The system that will be discussed comprises of an ash reburn cell, which is fed with ash from the existing ash handling system (modified to reroute ash to the chamber), inlet air ducting, outlet gas breeching, and controls to make up a complete package. Combustion air is taken from a separate combustion air fan located below the combustion chamber.

The complete ash reburn system (patent pending) was designed and supplied by both Riley Stoker Corporation, Worcester, Massachusetts and Konus Energy Systems, Atlanta, Georgia.