| 摘要 |
PURPOSE:To greatly reduce an organic solvent remaining in polycarbonate oligomer solid particles by drying polycarbonate oligomer wet powders by the use of a vertical dryer with a specific structure and having an agitator with a specific function. CONSTITUTION:Wet powders of polycarbonate oligomer including 0.5-20wt.% moisture and a 0.01-5.0wt.% organic solvent are placed into a vertical dryer with an agitator having stirring blades comprising a spiral metal sheet connected to the stirring shaft and capable of moving powders in the vertical upper direction through rotation, and with a structure capable of heating powders via the heat transfer surface. While rotating the stirring blades comprising a spiral metal sheet and putting the powders into contact with the heat transfer surface by centrifugal forces, they are moved to the vertical upside of the dryer so as to dry the wet powders. In this way, the occurrence or contamination of dusts is prevented, and drying process can be extremely shortened, thereby improving the quality, saving the process, and reducing manufacturing costs. |
