Single Stage Crushing and Separation Characteristics of Waste Mid-sized Refrigerators and Small Domestic Appliances

Abstract

Mechanical disintegration or shredding is an important aspect in the recycling process. Taking place at the beginning of the processing sequence, it significantly affects the efficiency of downstream processing stages. Each type of shredder shows specific characteristics, such as shear force or impact force. Currently, new types of vertical hammer-style shredders are being developed. These shredders use intense impact and shear force to handle most appliances. This study will examine the application of a single-stage crushing instead of the current recycling centers four-stage process. Several disposed appliances, including 75 L refrigerators and five major types of small domestic appliances (vacuum cleaners, videocassette recorders (VCRs), electric rice cookers, fans, and electric heaters) were shredded using high-speed vertical shredders under varying discharge clearance conditions. The fragments were analyzed according to their size, composition and degree of liberation. Also separation experiments were conducted for the small domestic appliance fragments. Based on the results, the high-speed vertical shredders performed sufficiently for single-stage shredding to substitute the current four-stage process, with the optimal conditions suggested according to the requirement or types of appliances.