Publications des agents du Cirad

Cirad

A combined method for drying and preserving wood in a single step process

Colin O., Dupuis C., Mougel E., Zoulalian A., Thévenon M.F.. 2000. In : 31st International Research Group on Wood Preservation Annual Meeting, Kona, USA, 14-19 may 2000. Stockholm : IRG, 10 p.. International Research Group on Wood Preservation Annual Meeting. 31, 2000-05-14/2000-05-19, Kona (Obsolète, voir territoire CS).

Based on a convective dryer, this process allows to dry and treat wood blocks with diffusible preservatives in the same time. A boric acid solution (heated to fix the wet temperature of the system) is pumped and introduced in the flow system through a venturi, where the air coming back from the drying cell also arrives. The role of the venturi is to create a dispersion of boric acid solution micro-droplets, which ones are then carried along by the air flow (heated to fix the dry temperature) and introduced into the drying cell. As wood is progressively drying, boron is able to deposit onto the wood and to diffuse until drying is achieved. Pine and beech mini-blocks (20x20x70 mm) where shown to be dried (from green state to 12%-10% moisture content) and also treated with boric acid. Amongst all parameters, dry and wet temperatures seemed essential for an efficient wood treatment, with boric acid solutions ranging from 1% to 5% (w/w). Colorimetric tests and extractions have been performed to assess boron penetration and retention of such treated wood, and biological tests have also been carried out. From these preliminary trials, it appeared that wood processed by this combined method could readily meet the requirements for a hazard class 2.
Communication de congrès

Agents Cirad, auteurs de cette publication :