Measuring moisture content profiles in a board during drying: a polychromatic X-ray system interfaced with a vacuum/pressure laboratory kiln

A standard X-ray source and an energy-sensitive detector were placed on both sides of a wood dryer which operates over a wide range of drying conditions. The spectrometric X-ray intensities transmitted through the wood sample were related to the mass concentration of wood and water using a rigorous calculation needed in the case of a polychromatic X-ray beam. The source and the detector are carried by a motion controller in order to scan the sample at different drying times and determine the moisture content (MC) profile along the board thickness. Treatment on spectrometric data and the evolution of the MC profiles in a Norway spruce board (Picea abies) are presented in this work.

[1]  D. Bentz,et al.  Preliminary observations of water movement in cement pastes during curing using X-ray absorption , 2000 .

[2]  L. O. Lindgren.  Medical CAT-scanning: X-ray absorption coefficients, CT-numbers and their relation to wood density , 1991 .

[3]  P. Wiberg,et al.  Moisture flux determination in wood during drying above fibre saturation point using CT-scanning and digital image processing , 1999, Holz als Roh- und Werkstoff.

[4]  Dsu.  An introduction to x-ray spectrometry , 1976 .

[5]  P. Stroeven,et al.  X-ray absorption study of drying cement paste and mortar , 2003 .

[7]  R. Rémond,et al.  Approche déterministe du séchage des avivés de résineux de fortes épaisseurs pour proposer des conduites industrielles adaptées , 2004 .

[8]  Ian Turner,et al.  TRANSPORE: A GENERIC HEAT AND MASS TRANSFER COMPUTATIONAL MODEL FOR UNDERSTANDING AND VISUALISING THE DRYING OF POROUS MEDIA , 1999 .

[9]  Paul Glover,et al.  High Resolution Measurement of the Surface Layer Moisture Content during Drying of Wood Using a Novel Magnetic Resonance Imaging Technique , 2002 .

[10]  P. Wiberg,et al.  HEAT AND MASS TRANSFER DURING SAPWOOD DRYING ABOVE THE FIBRE SATURATION POINT , 2000 .

[11]  K. L. Williams.  Introduction to X-Ray Spectrometry , 1987 .

[12]  Jugo Ilic,et al.  Moisture Content in Drying Wood Using Direct Scanning Gamma-Ray Densitometry , 1993 .

[13]  Patrick Perreé,et al.  PROTOTYPE HIGH TEMPERATURE/HIGH PRESSURE KILN FOR THE EVALUATION OF WOOD DRYING SCHEDULES , 2000 .

[14]  Jarl-Gunnar Salin.  Mass transfer from wooden surfaces , 1996 .

[15]  Ron Jenkins,et al.  An introduction to X-ray spectrometry , 1974 .