Energy and exergy analysis of industrial fluidized bed drying of paddy

• Energy and exergy analysis of industrial fluidized bed paddy drying are presented.
• Energy usage varies from 38.91 kJ/s to 132.00 kJ/s.
• Energy usage ratio is found to vary between 5.24 and 13.38%.
• Exergy efficiency varies from 41.30 to 58.14%.
• Only 31.18–37.01 % exergy are utilized in the paddy drying system.

This paper presents energy and exergy analysis of industrial fluidized bed paddy drying. The maximum design capacity of the dryer was 22 t/h. Existing energy and exergy models developed applying the First and Second law of Thermodynamics are employed to estimate the amounts of energy used, the ratios of energy utilization, magnitude of exergy losses and exergy efficiencies during the drying process. The analysis shows that energy usage and (EUR) energy utilization ratios vary between 38.91 kJ/s to 132.00 kJ/s and 5.24–13.92 %, respectively while exergy efficiency vary from 46.99 to 58.14%. A simple exergy balance reveals that only 31.18–37.01 % exergy are utilized for drying of paddy and the remaining large amount of exergy are wasted. Exergy can be increased through providing sufficient insulation on dryer body and recycling the exhaust air which need to be studied further for investigating the economic feasibility.