Journal of the Korean Wood Science and Technology

The Korean Society of Wood Science & Technology (한국목재공학회)
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Effect of Alternating Vacuum and Release Process on Drying Characteristics of Log Cross Section during Radio Frequency Drying

  • Xie, Dan (Department of Wood Science & Technology (Institute of Agricultural Sci. & Tech.), Chonbuk National University) ;
  • Lee, Nam-Ho (Department of Wood Science & Technology (Institute of Agricultural Sci. & Tech.), Chonbuk National University) ;
  • Chang, Yoon-Seong (Department of Forest Sciences, College of Agriculture and Life Sciences, Seoul National University) ;
  • Yeo, Hwanmyeong (Department of Forest Sciences, College of Agriculture and Life Sciences, Seoul National University)
  • Received : 2013.08.22
  • Accepted : 2013.09.24
  • Published : 2013.09.25
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Abstract

Log cross sections of yellow poplar were dried in a radio frequency vacuum (RFV) dryer under alternating vacuum and release (AVR) process. The average moisture content (MC), temperature and vapor pressure at the volumetric center were monitored as functions of time. Three different log thicknesses (33, 60 and 75mm) were tested. The results show that the AVR process caused an increase in the drying rate when the moisture content was above fiber saturation point (FSP, about 30% MC) but that it had an inverse effect on the drying rate when the MC was below FSP. The effect of the AVR process on the drying rate decreased, and the severity of heart checks increased, with the increase in the thickness of the specimens.

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References

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