Simplification and Energy Saving of Drying Process Based on Self-Heat Recuperation Technology

Abstract

A simplified drying process based on self-heat recuperation (SHR), which can further reduce energy consumption compared to previous SHR drying processes, is proposed. The specific energy consumption (SEC) of the SHR drying process was evaluated at various air flow rates and compared with a mechanical vapor recompression (MVR) drying process with superheated steam. The results show that the SEC of SHR can be reduced from 474 to 147 kJ (kg-H₂O evaporated)⁻¹ by removing heat exchangers for preheating. The SEC of the simplified SHR process was only 1/16 of a conventional drying process with heat recovery and 3/5 of an MVR process. Exergy transfer of the process was also analyzed and summarized as exergy flow diagrams.

Keywords:

• Air flow rate
• Energy saving
• Exergy flow
• Mechanical vapor recompression (MVR)
• Self-heat recuperation (SHR)
• Simplified process

Notes

Note: ○: with the unit, ×: without the unit.

^a Thermal efficiency.

^b Negative values mean recovered compression work.