IMPROVING THE COMBUSTION PERFORMANCE OF THE FARLEIGH NO. 3 BOILER

MOST currently operating boilers in the Australian sugar industry were designed to produce the steam a factory needed and to dispose of the bagasse the factory did not need. Eventually these boilers will be replaced by newer high efficiency, high pressure boilers that will allow factories to export more electricity and/or produce more surplus bagasse for diversification activities. This however may not happen for at least thirty years. In the meantime, most sugar factory boilers in Australia will produce steam renewably, but not very efficiently. While most attention has focussed on the recent and current cogeneration projects, the large number of older low efficiency boilers in the industry represents low hanging fruit that can in many cases, be improved at relatively low cost for significant gains. Farleigh’s No. 3 boiler is one of these units. Earlier measurements identified problems with the distribution of air and gas flow through this boiler. Installing turning vanes in the air heater air inlet plenum helped make the flows more uniform but did not completely address the problem of poor combustion performance on the right side of the furnace. Further investigations, prompted by high wear of the superheater tubes on the right side of the boiler, were undertaken and what is believed to be the root cause of the combustion problems was identified.