Kiln Drying Forum
Wood Drying Topics => General Discussion => Topic started by: admin on November 27, 2015, 02:14:08 AM
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Pasteurization of wet wood as either lumber or logs for export is becoming standard practice. Can anyone tell me about dielectric heating and if it is the best way to quickly pasteurize wood?
(This question was fielded from and is posted on behalf of the sawmill industry.)
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till recently, methyl bromide was the chemical of choice for making sure bugs were dead before green wood was exported. Since methyl bromide was banned, and no other safe/good chemical is in the pipeline, steaming is the only alternative. Now steaming is OK, however since the heat has to slowly move to the center of the timber or log, it takes time and there is some drying happening at the same time. A faster alternative is dielectric heating and in particular, radio frequency heating for batch pasteurization of logs and timbers. Recent research has concluded that in about three to four hours of RF heating, large volumes of wood can be pasteurized completely with minimum loss of moisture (remember, we have to have them still in green condition for exporting) and no other defects like checking, warp or casehardening.