A 650 kilogram capacity cupola furnace was fabricated from locally available materials for the production of cast iron using pig iron, contaminated steel scraps, foundry returns and fluxes. The main fuel used is metallurgical coke. After analyzing the design parameters, the shells were fabricated in four segments for easy lining: the stack zone, preheating zone, combustion zone and the hearth. Mild steel sheet of 4 mm thickness was procured, marked out
as per the drawing, sliced and rolled into cylindrical shapes and the joints welded continuously. The internal configuration was lined first with asbestos paper measuring 4 mm thick using water-glass to enable it adhere to the internal shell of the segments, thereafter, a less dense insulating refractory material was used and finally fireclay refractory bricks was used for lining since it interfaces directly with the molten metal. The various segments were then assembled and erected with the blower connected to the combustion zone. This report
also contains the materials and components bill.
Cupola furnace is a melting device used in foundries majorly to produce cast iron and bronzes. It is a continuous melting shaft furnace capable of processing different range of raw materials from pig iron, oily and contaminated steel scraps, foundry returns and ferroalloys (Edward, 2008). Its main energy source is metallurgical coke. It is one of the oldest methods of producing cast iron, and it remains the dominant method because of its simplicity and low fuel cost (Moore et al, 1995). The size of a cupola is expressed in diameter and can range from 0.5 m to 4 m (Larsen et al, 2005). The overall shape is cylindrical and the equipment is arranged vertically, usually supported by three or four legs. The overall look is similar to a large “smokestack” (Larsen et al, 1995). The bottom of the cylinder is fitted with doors which swing down and out to “drop bottom”. The top where gases escape can be open or fitted with a cap to prevent rain from entering the cupola.