A simulation study of parameters influencing microwave heating of seaweed (Eucheuma cottonii)

Abstract

Currently, the process of drying seaweed has been using conventional technology, utilizing sunlight directly. It depends on weather conditions when the rainy season arrives, the drying process will take longer time even 3-4 days. The longer duration of drying causes seaweed's quality degenerate. Previous studies have proved that drying materials use microwave energy can reduce processing time significantly. Heat transfer and electromagnetic field effect on seaweed drying in a microwave oven were studied using a three-dimensional simulation. The parameters observed included variations of power microwave (400, 500, and 600 W), seaweed thickness (3, 5, 7 cm), and waveguides position (top and side). Variation of magnetron energy in microwave heating is affecting the electromagnetic field's value and changing seaweed temperature. As increasing received energy from the magnetron, seaweed temperature and electromagnetic field are ascending. Seaweed that is heated in 3 cm thickness results rising temperature higher than 5 cm and 7 cm thickness. Waveguide located at the top cavity is generating electromagnetic field value higher than it located at the side cavity. As verification method, heating fresh seaweed use microwave oven was resulting similar pattern both electromagnetic field and temperature. The lowest moisture content of seaweed is achieved at the treatment of 600 watt magnetron energy and 3 cm thickness of seaweed.