SUGARCANE BAGASSE DRYING USING HOT AIR - CASE STUDY OF LAB-MODEL

摘要

Bagasse is the Fuel used as an Energy source of Sugar industry. Optimum utilization of the heat energy which, bagasse would give up by combustion is necessary. Moisture content of bagasse has pre-dominating influence on its heating i.e. calorific value. The potential of mechanical dewatering of bagasse and that it is limited to 45 per cent moisture. Roll crushers rarely perform to this limit and an average of 48 per cent moisture content would be excellent performance. A further moisture reduction of bagasse can be achieved by thermal drying methods. Bagasse drying will provide the missing link in power development, saving and optimization of heat energy available of bagasse.Bagasse dryer design include mainly the design of the path which is followed by the mixture ofhotflue gases or hot air along with bagasse at last mill run condition. Bagasse drying is affected by moisture content of bagasse, amount of fibre in sugarcane, mill practices applied during extraction of juice, mill setting, imbibition practices etc. If, the moisture content of last mill bagasse which is going to boiler for firing is reduced then it raises efficiency of combustion and boiler efficiency.As, the moisture content is reduced the calorific value of bagasse rises, this helps in rising boiler efficiency. As less amount of water is to be evaporated and raise its temperature to superheated temperature at boiler flue gas condition with extraction of heat from superheated steam in flue gas again back in super-heater, economizer and air pre-heater wasting some heat to nearby atmosphere, formationof scale at heat exchangers leading to less efficiency of heat extraction. Current scenario of electricity has been changed. Use of bagasse dryer is optimizing the electricity generation in sugar plant. For 4000 TCD sugar plant with cogeneration can generate additional 1.429 MW of electricity to 12 MWe. Pay back period for bagasse dryer is single season along with 670% profit.