Numerical and Experimental Study of a Thermal Separation Process, for Electrical Cable Waste Components

Abstract

The continuous update of electrical products and the rapid development in the power industry are leading to an increase in cable waste. Due to the high purity of copper in cables and the low energy consumption when they are recycled, waste cables are a valuable source of raw materials for the reclaimed metal industry. However, achieving complete separation between the metal and the insulator, in recycling electrical cable waste, has always been a challenge. This paper presents an original approach to liberating the metal conductor from the insulator, without shredding the cables into small pieces and using subsequent multistep separation processes. A cable is passed between two rollers that rotate at the same speed. The outer surface of one roller is heated below the melting point of the thermoplastic insulator; the other roller remains at room temperature. The stripping process was studied through both numerical simulations and experiments. A methodology for numerical simulation of the cable stripping process is proposed, using SolidWorks Simulation software. In addition, a prototype of the cable stripping machine was designed and built. Numerical simulations revealed that the insulator, with lower thermal conductivity than the conductor, heats unevenly, resulting in a bending of the insulator and the subsequent exposure of the metal conductor. Experimental findings show that the optimal peripheral speed of the rollers for achieving complete separation, depends on the thickness of the insulator and decreases by 4.5 times, as the thickness increases 1.8 times.