ProLigno / ProLigno 2010 Issue 2  
     
 
 
   
 

 


 

 

 

Helmuth RESCH

Drying Wood With High Frequency Electric Current

PUBLISHED IN:
Society of Wood Science and Technology, Madison USA, 2009
ISBN 978-0-9817876-1-9, 84 pg.

For orders, please contact the author at the following address: vicki@swst.org

 

This book offers a broad coverage of research and development over many decades up to industrial applications of a special drying method, using high frequency electric current for wood and wood products. The book aims at providing some understanding of the many ways to employ this technology, characterised by rapid and relatively uniform heat transfer inside wood, resulting in high drying rates and avoidance of various drying defects, like casehardening and oxidative discoloration. The greatest emphasis is placed on the method of combining radio-frequency heating with vacuum drying, but also on recent research concerning the use of microwaves. Considerations on energy consumptions, technical feasibility and economics complete this reference piece of work.

 
 

Graham Ian BRODIE

Innovative Wood Drying - Applying Mcrowave and Solar technologies to Wood Drying

PUBLISHED IN:
VDM Verlag Dr. Muller, Saarbrucken, Germany, 2008
ISBN 978-3-639-04670-0, 110 pg.

For orders, please contact the author at the following address:
http://www.amazon.com/exec/obidos/ASIN/3639046706/chainreadin04-20

 

Emphasis in the hardwood industry is shifting away from structural-grade timber toward the production of high-value products. Many dense hardwoods are extremely difficult to dry without causing defects, such as: splitting, warping, twisting or collapse. Solar power is a convenient and cheap energy source that can be easily applied to timber drying. It greatly improves wood quality and reduces drying costs by 50% or more compared to conventional kilns; however solar kilns are still slow and powerless to manipulate the density and moisture permeability of wood. A thorough mathematical study of the microwave heating phenomenon demonstrates that intense microwave energy can blast tiny holes through the wood structure, creating microscopic pathways through which moisture may readily move. Thus, solar kln drying times can be reduced by ca. 33%, without affecting the drying quality.

 
 

 

 
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