Abstract
Vacuum heating separation is one of the promising methods for removing insulation oil from used pole transformers. Using this method, insulation oil and PCBs are removed from the pole transformers by vaporizing under vacuum condition at the temperature of 200°C. The vacuum heating separation method has a high removal performance without pyrolyzing of insulation oil, PCBs and pole transformers. However this method requires a long treatment time to detoxify the pole transformers, because the pole transformers were heated by radiative heat transfer under vacuum condition. The purpose of this study is to make the vacuum heating separation method more efficient by using a vibration dryer. This new method was able to reduce not only the treatment time, but also running cost dramatically. From the experimental estimation, the heating time was shortened 48-50 % and the equipment space was saved 84-88 % in comparison with conventional plants. The fundamental performance of PCBs removal from various samples by the vacuum heating method was also investigated. As the result, PCBs was removed below the removal standard on the both copper and insulation paper, and PCBs concentration in the activated alumina was also reduced.
