Reduction of Exhaust Steam Consumption by Vapour Bleeding at Kakira Sugar Limited

Abstract

Heating is the most energy consuming expense that a cane sugar company incurs during its operation and the success of a company depends on how this operation is done (Rein, 2007). The energy for heating is provided by steam. Therefore, steam economy is very vital for a sugar factory. The objective of this study was to reduce steam consumption by vapour bleeding and evaluate the saving in steam as a result of vapour bleeding which implies a lower steam % cane. In this study four syrup samples were collected daily and average value was calculated for brix of both the double effect vapour cells and each body of the quadruple effect evaporators. Temperature of mixed juice, inlet and outlet temperature of juice from primary, secondary and clear juice heaters. Likewise, condensate flowrate from the vacuum pans was measured and average value was calculated. The total average consumption of steam for process operations was found to 162t/h with bleeding from DEVCS and 3rd body of the quadruple effect evaporator. With additional bleeding from the first and second bodies of quadruple effect evaporator, saving in steam would be 24.05t/h which corresponds to 13% of the total steam used in process. This would lead to saving in bagasse and less power consumed by the pump since power depends on flow rate.