Investigation on the Effect of Condensing Moisture before Heating Air on the Performance of a Batch Tray Dryer: Application to the Drying of Vanilla

Abstract

This article presents the results of an investigation of the effect of pre-dehumidifying the drying air before it is heated and supplied into a batch tray dryer. Dehumidification is achieved through moisture condensation as the air flowing through a coil is cooled by chilled water from a cold source. As an example, this process is applied to the drying of vanilla and is based on a numerical method already validated by former results. Then, it is established through comparisons with a conventional batch tray dryer model that pre-dehumidification significantly reduces drying time. Furthermore, preheating air by an intermediate heating source reduces total energy consumption of the primary heating system to a level depending on the preset drying temperature. As regards batch tray dryer design and optimization purposes, these results open up particularly interesting heating and cooling sources utilization prospects.

Keywords:

• Batch tray dryer
• Chilled water
• Drying
• Energy efficiency
• Vanilla

ACKNOWLEDGEMENTS

We thank Professor Daguenet Michel and Dr. Ratobison Rémi, Laboratoire de Thermodynamique et Energétique, Perpignan University, France for the provision of data.