Abstract:
Salt bath furnaces are usually the most expensive equipment in any manufacturing /materials processing industry. Proper understanding of their handling and technological principles are required for effective usage. Most imported salt bath furnaces are power consuming and require regular continuous power supply. This informed the need to develop a low power consuming diesel fired salt bath furnace that will have a pre-heating chamber attached. The operation of the developed furnace will not be interrupted by the Nigerian power fluctuation and failure. Design drawings were developed and mild steel sheets were used in the fabrication of the furnace casings. Other materials and components required for the development of the desired diesel fired furnace were selected based on local availability, functionability, durability, cost and safety in use. The furnace lining was done using Ijapo and Ikere clay to ensure heat preservation in the inner pot of the furnace. Performance evaluation test of the furnace in terms of fuel economy, rate of heating, temperature homogeneity, temperature stability and cyaniding efficiency were carried out to evaluate the performance of the furnace. From the result obtained, it was observed that the diesel fired salt bath furnace has a fast heating rate of 11.67oC/min with a fuel consumption rate of 3.60 litres/hr, when compared with the imported salt bath furnaces. The developed diesel fired salt bath furnace using locally sourced materials was also discovered to be of lower cost in production coupled with low fuel consumption rate, controllable heating rate, stability of heating temperature and heat uniformity in the inner chamber of the furnace to bring about qualitative products and more effective result. It also has longer estimated life, safe ease to operate. The developed diesel fired salt bath furnace was also found to be suitable for effective carburizing operation on both medium and low carbon steels of which a minimum hardness of 70HRA recorded
