Theoretical study of microwave heating patterns on batch fluidized bed drying of porous material

Guohua Chen, Wei Wang, Arun S. Mujumdar

Research output: Journal article publicationJournal articleAcademic researchpeer-review

64 Citations (Scopus)

Abstract

The effects of microwave heating patterns were investigated for the case of batch fluidized bed drying by solving numerically a coupled heat and mass transfer model. Three patterns, uniform, sinusoidal and rectangular waves, were examined with the average electric field strength kept constant at 1000 V/m. Properties of apple were used to represent porous materials. The results show that the magnitude and distribution of the moisture, temperature and pressure within a particle can be significantly affected. More importantly, the drying time and microwave energy consumption change with the pattern of how microwave heating is applied. Particularly, intermittent heating with a rectangular wave pattern has the most microwave energy consumption but the shortest drying time. For a particle size of 5 mm, airflow rate of 2 m/s and temperature of 60°C, the bed area factor fAof 100, the drying time is, respectively, 1600, 2000, 2400 s for rectangular, sinusoidal, and constant microwave heating. The values of microwave energy consumed for the three cases are, respectively, 2145, 1980, and 1560 kJ/kg water evaporated.
Original languageEnglish
Pages (from-to)6823-6835
Number of pages13
JournalChemical Engineering Science
Volume56
Issue number24
DOIs
Publication statusPublished - 14 Dec 2001
Externally publishedYes

Keywords

  • Apple
  • Bed area factor
  • Drying rate
  • Energy consumption
  • Moisture

ASJC Scopus subject areas

  • Chemistry(all)
  • Chemical Engineering(all)
  • Industrial and Manufacturing Engineering

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