REDUCING FACTORY STEAM CONSUMPTION FOR COGENERATION AT CONDONG MILL

DURING 2008, the New South Wales Sugar Milling Co-Operative commissioned 30 MW generators and 150 t/h high pressure boilers at both the Condong and Broadwater Sugar Mills for cogeneration purposes. At the Condong site, significant changes were made to the process side of the factory during 2007 to reduce factory steam consumption and thereby maximise the steam available for cogeneration. This paper details the stages and results of the project including: modelling the old evaporator and heater stations; modelling proposed layouts and selecting the most suitable configuration; practical steps in implementing the chosen configuration; and factory performance after the changes; further possible changes. By changing the evaporators from two quintuple sets to one sextuple set, and by using extensive vapour bleeding down to vapour 5, the factory steam consumption has been reduced from 51% steam on cane to approximately 40% steam on cane. Additional heaters and condensate flashing were also used to obtain this improvement in efficiency. This paper provides a good example of the efficiency improvements that can be achieved using conventional heaters and Robert evaporators.