Estimating electric power requirements for mechanically shredding massage chairs and treadmills at a recycling plant

Abstract

South Korea has operated under laws to collect and recycle the waste of electrical and electronic equipment (WEEE) utilizing a system based on the Extended Producer Responsibility (EPR) system since 2003. In 2020, the number of products managed by the EPR increased from 27 to 50. Among the 50 products, massage chairs and treadmills are recognized as the items avoided in recycling centers or by recyclers due to their large volume, large weight, and long disassembly times. This study was a preliminary study in which the physical shredding process for massage chairs and treadmills could be introduced, and the electrical power requirements calculated. In the methodology, Vickers hardness was measured by sampling two actual products, and the tensile and shear strength were calculated from the hardness. Based on the shear strength, the force affecting the cutter was calculated and converted into torque and horsepower. In particular, the actual specifications of the crusher, designed and operated in the recycling center, were applied to the study, and the design was based on the treatment capacity of 10 tons per hour. Conclusively, the proper electrical power for crushing the massage chair and treadmill was analyzed as 719.5 and 459.7 HP, respectively.