Drying Kinetics, Energy Consumption, and Quality of Paddy (MAR-219) during Drying by the Industrial Inclined Bed Dryer with or without the Fluidized Bed Dryer

Abstract

The performances of industrial dryers, namely the inclined bed dryer (IBD) and the fluidized bed dryer (FBD) combined with IBD, in terms of drying kinetics, energy consumption, and quality of paddy were investigated in this study. Drying parameters used in a single-stage paddy drying using IBD and a two-stage drying using FBD combined with IBD were analyzed to assess the existing performances of the drying techniques. The overall performances of the current drying practices exhibited inconsistent results with the operating parameters, such as drying air temperature, drying time, and air flow rate among the drying process lines. Distinct variations in moisture reduction and energy consumption of the drying systems were identified. Poor performance of the industrial fluidized bed dryer was observed in the case of drying in low capacity that caused higher specific energy consumption. However, the quality of milled rice obtained from both drying systems was found to be almost similar. Minimal process time (i.e., up to 24.5% less) was found in the paddy dried with FBD as the first-stage drying, followed by IBD as the second-stage drying.

Keywords:

• Energy consumption
• Fluidized bed dryer
• Inclined bed dryer
• Industrial paddy drying
• Rice quality

ACKNOWLEDGMENTS

The authors would like to express their sincere thanks to BERNAS, Malaysia, for the financial support, as well as the use of the drying and milling sites for data collection. Our heartiest gratitude also goes to the Food Analysis Laboratory of UPM-BERNAS for facilitating the milling test.

Notes

Drying lines 5 and 6 were followed additionally to compare with others lines, 02, 03, 04, 05, and 06 are the IBD number used of the complex, FBD; fluidized bed dyer, IBD: Inclined bed dyer, AAD; Ambient air drying, M_i: Field moisture content, Imp: Impurity after pre-cleaner, MC_i: Initial moisture content, V: Bed air velocity, Q: Air flow, T: Drying temperature, h: Bed thickness/weir height, F: Feed rate, TAW: Residence time, SAFR: Specific air flow rate, T_db: Dry bulb temperature of natural air, RH: Relative humidity.

FBD: Fluidized bed dryer; IBD: Inclined bed dryer. The left and the right value in each column represents the data for the first and second seasons, respectively. The (–) sign indicates increased drying time.

FBD: Fluidized bed dryer; IBD: Inclined bed dryer. The ^*left and the ^**right values in each column represent the data for the first and second seasons, respectively. Total energy was calculated as [a sum of energy consumption in all the drying stage(s)/a sum of water mass evaporated in the drying stage(s)].