Cost Reduction in Cast Iron Rotary Furnace: A Thermodynamic Approach

In this paper، in order to introduce manufacturing cost reduction methods، using a thermodynamic approach، the performance of cast iron rotary furnaces is analyzed. To do so، the furnace atmosphere is chosen as a control volume. Then، heat sources، heat sinks and heat loss mechanisms are recognized and the first law of thermodynamic is applied to the control volume. The analysis showed that radiation is the dominant heat transfer mechanism and a large portion of heat generated by fuel consumption is lost through hot gasses that leave the furnace and due to heat conduction from furnace drum. Consequently، more than 90 percent of input energy to the furnace is lost. The first method to reduce the fuel cost is to pre-heat the input air which can reduce the fuel consumption by 10%. The other method is to replace the conventional fuel of cast iron rotary furnace –Fuel Oil- with Natural Gas، which is very effective to reduce fuel cost because the price of natural gas is much lower than the price of fuel oil.