Energy and Exergy analysis of tropical fruits dehydration using different dryers
Special Symposium - Innovations in Food Technology (LMC Congress)
Innovations in Food Technology - Poster Session (LMC/Food - P1)
Keywords: Drying Process, Exergy, juice, extract
Drying is an important operation for food industry, which is based on a simultaneous heat and mass transfer of moisture to an air stream. Although, there are many different kinds of dryers, it’s difficult to analyse the conditions of the operation for selecting one or another. In this work, the first law of thermodynamics represented in energy consumption is applied to the process of drying tropical fruits (juices) and vegetables (extracts); These results are subsequently analysed using exergy balances for different technologies. Convective drying, vacuum drying, spray drying and freeze–drying were analyzed. For that purpose, a simulation using different models for each dryer was performed calculating the heat requirements of each process and outlet conditions according to parameters given in the literature.
Selection of the most appropriated models was based on accuracy and calculation time. After that, an economic comparison is made. Application of the second law results in an exergy balance for every part of the process. This exergy balance yields an estimate of the quantity of exergy loses, that are useful as a thermodynamic comparison of the processes. This mathematical tool gives an assessment between the processes and also permits an analysis of the most efficient and least efficient part of the drying equipment. Useful quantitative results agreeing with experimental data were obtained, allowing the choice of most convenient alternative for different fruits drying.
Presented Wednesday 19, 13:30 to 15:00, in session Innovations in Food Technology - Poster Session (LMC/Food - P1).
