Experiment of Drying Kelp with High Voltage Electric Fields

Abstract

In order to improve the drying qualities of seaweed, a new drying technology with the high voltage electric field was put forward for seaweed in the paper. The kelp were dried under a direct current (DC) high voltage electric field (HVEF) using a multiple point electrode and a grounded rectangle stainless steel plate at 15degC. The results indicate that the high voltage electric field can improve the drying rate of kelp significantly, at the same temperature, the higher the voltage between the two electrodes is, the faster the drying rate will be. With 45 kV voltage, HVEF with multipoint to a plate electrode system could evaporate 42.0% of the total moisture from kelp on 1 h exposure. Oven drying at 60 degC and ambient air at 15 degC for 1 h could dry 65.3% and 6.2% of the total moisture from the kelp respectively. The average rate of HVEF drying, oven drying and ambientair drying from first minute to thirty minutes were 34.50 mg/min, 46.48 mg/min and 5.39 mg/min respectively. Quality factors for HVEF-dried kelp exhibited better water absorption, better color, lower distortion and softer than the oven drying.