Material property changes during electrohydrodynamic (EHD) drying a closer look into the falling rate period

Area of Science:

• Drying Technology
• Mass Transport Phenomena
• Electrostatics

Background:

• Electrohydrodynamic (EHD) drying is an energy-efficient alternative to hot air drying.
• EHD drying relies on corona wind for enhanced convection but faces limitations in internal moisture transport during the falling-rate period.
• Electric fields may enhance internal moisture transport during EHD drying.

Purpose of the Study:

• To theoretically analyze and experimentally characterize the electric potential evolution during EHD drying of porous materials.
• To quantify the impact of electric fields on internal mass transport during EHD drying.
• To advance the understanding of electrically driven mass transport for optimized EHD drying technologies.

Main Methods:

• Theoretical analysis of electric potential distribution.
• Experimental characterization of EHD drying of thin porous layers.
• Quantification of electric potential and material permittivity during the drying process.

Main Results:

• During the constant-rate period, low electric potential indicates corona wind-driven convection dominates.
• In the falling-rate period, increasing electric potential suggests potential electromigration.
• Simultaneously, increasing material resistance due to moisture loss may counteract electromigration effects.

Conclusions:

• The study quantifies electric potential and material permittivity during EHD drying.
• Findings enhance understanding of electrically driven mass transport in porous media.
• Results support the development of optimized EHD drying processes and technologies.