2009 年 75 巻 752 号 p. 824-830
To realize thermal recycling of waste plastic resin as one of alternative fuels, detailed microscopic observation is made of the multiphase process in a micro spherical PET particle under abrupt heating. It is observed that multiple internal micro bubbling occurs within the micro PET-droplet independent of its initial diameter and is triggered by flash vaporization of thermally decomposed products of PET resin. Internal random explosions of micro bubbles follow and blow up multiple irregular micro jets from the micro droplet. The latter forces the micro droplet to move around irregularly on the fine wire, while micro diffusion flames are randomly established behind them. Based on the observation results, the key factor to such a violent burning process of PET particles as to exceed that of well-known volatile liquid fuels can be attributed to the internal multiple micro bubbling due to the flash vaporization of thermally decomposed products.