An optimized design of a PLC-based controlled microwave vacuum dryer for preliminary drying studies on rice bran

• Main Authors: Rogelio, Jayson P., Liza, Fred P., Abulencia, Geoffrey L., Soriano, Joey Kim T., Baldovino, Renann G., Tolentino, Tracy Ann U., Macanip, Virgilio Y.
• Format: text
• Published: Animo Repository 2015
• Subjects: Drying apparatus; Rice bran—Drying; Manufacturing
• Online Access: https://animorepository.dlsu.edu.ph/faculty_research/3181
• Institution: De La Salle University

This study presents an optimized design of a PLC- based microwave vacuum dryer which was used to conduct preliminary investigation of the effects of drying parameters on the drying kinetics of rice bran. The study initially conducted a methodical analysis of the microwave chamber and its auxiliary attachments. Using CST Microwave Studio simulation software, it was seen that the best design for a 30-L MV chamber operating at 2.45 GHz is a cylindrical chamber with a radius of 202 mm, length of 400 mm, and with 2 perpendicular feeders located near the ends of the chamber. To achieve uniform product heating, a rotary drive assembly was incorporated into the system (i.e. mixing the product during the drying process). A PLC-based control box with HMI display was developed to constantly monitor the drying kinetics of rice bran. Subsequently, drying experiments were then carried out. The study successfully used fractional factorial design (FFD) with center points to model the interaction effects on MVD parameters on moisture extracted and color of rice bran. Experimental verification of the model resulted to 1.18% error of the actual versus predicted moisture extracted.