An Investigation on Thermal Recycling of Recycled Plastic Resin (Spherically Symmetric Analysis of Abrupt Heating Processes of a Micro Plastic-Resin Particle)

Abstract

To burn plastic-resin powder as an auxiliary fuel and to realize clean and effective thermal recycling of a great deal of recycled plastic resin, fundamental elucidation of physical and chemical characteristics of a plastic-resin particle subjected to sudden heating is extremely important and necessary. In this case, it is indispensable to measure the temperature history in a micro plastic resin particle under abrupt heating and to get quantitative knowledge of its life time. However, the diameter of micro plastic particles is so small that measurement of the temperature history within it is found to be extremely difficult. In this paper, therefore, the spherically symmetric analysis is applied to the abrupt heating process of a micro spherical plastic resin particle. Variations of the temperature history and the life time with the ambient temperature and the initial particle diameter are numerically estimated, by dividing the entire heating process into four independent periods; the solid heating period, the melting period, the liquid heating period, and the thermal decomposition period. Effect of Nusselt number on the life time is also discussed.