| 摘要 |
<p>PURPOSE:To improve heating efficiency and accelerate thermal decomposition in a thermal decomposition vessel of a waste polyolefin liquefaction apparatus by installing, in the decomposition vessel, a stirrer which changes its rotational speed with the change in viscosity of a thermal decomposition system. CONSTITUTION:A waste plastics liquefaction apparatus has a conveying means (e.g. a screw feeder 5) which communicates with a material feed section 2 and receives a waste polyolefin, a thermal decomposition vessel 3 which thermally decomposes the conveyed waste polyolefin. and a catalytic reactor 8 which catalytically converts the resulting vapor product. The thermal dcomposition vessel 3 has a stirrer 4 which rotates while changing its rotational speed with the change in viscosity of the waste polyolefin. For instance, at 120-220 deg.C the viscosity of polyethylene is at its peak and the stirrer speed is controlled to be low (50-80rpm) with a control unit 15. At higher than 220 deg.C, the stirrer is rotated at a higher speed (80-200rpm) until thermal decomposition begins at 420 deg.C. Thus, the power for stirring is not wasted, and a high-speed stirring in a low-viscosity region improves the thermal efficiency.</p> |
