Track: Energy

Abstract

Energy efficiency of furnace should be based on its ability to conserve heat within the combustion chamber. This mainly depends on the design and material selection of the furnace. The coal–fired furnace is common amongst the rural foundries in Limpopo province. The coal fired furnace is used to melt aluminium scraps for production of cooking three legged aluminium pots commonly used as cooking utensil and sold within the local and national  communities. The coal fired furnace is used due to its easy to manufacture, to operate and its low capital and running costs investment which is suitable for small batch production. However made of a mere superposition of two tinned drums,  the current coal fired furnaces  in rural foundries have long melting time ~ 6 hours, due to the design and material selected in manufacturing the furnace. This paper presents the analysis of design and material components of rural foundries furnaces in South Africa and studies the energy efficiency of the particularly coal fired furnace. Technical testing of energy in and output was conducted. Findings show that with a heat loss of 2929.92 MJ and only 2% energy efficiency the heat loss was one of the main contribution to the experienced long melting duration The insufficient supply of oxygen or air into coal fuel also plays critical role in the performance of the furnace, since combustion of coal depends greatly on the supply of oxygen or air.  To improve the heat retention and the energy efficiency of the coal fired furnace used in the rural foundries, a re-design of the furnace and selection of specified new lining materials are the main conclusions.