Design, Fabrication and Performance Evaluation of a Dual Powered Crucible Furnace for Aluminium Cans Recycling

Abstract

There is great need for metal scraps recycling and commercialization in Nigeria owning to the abundant and indiscriminate disposal of metal scraps which constitute health hazard to citizens through the blockage of drainage systems, causing erosion and flooding, defaces the aesthetics of the cities through mounting heaps of metallic waste. This research work designed and fabricated a manually operated dual powered tilting crucible furnace suitable for laboratory and workshop practice for recycling of aluminium cans and scraps and other low melting metals and alloys. It consists of a cylindrical stainless steel pot contained in a refractory lined mild steel square box, fired with both gas and electricity and incorporates a K-type digital thermocouple for temperature measurement. The stainless steel crucible pot has a diameter of 195mm, 312mm high and 3mm thick. The refractory material was locally developed from asbestos, clay, cement and perlite combined in the ratio 1:1:1:5 by volume. The fabricated furnace was tested for performance evaluation by melting different samples of aluminium cans using both gas and electricity. It was found that the furnace has fairly uniform melting rate with both gas and electric powered operations but has varying heating rate which decreased with increasing charge mass. The furnace also has no-load heating rates of 28.7oC/min and 20.1oC/min when powered with gas and electricity respectively. The furnace has a melting capacity of 〖0.0093m〗^3 for 25kg of aluminium charge with total output heat of 199.93MJ and thus suitable for use in small scale foundries and tertiary institutions