A Comparative Analysis Of Energy Consumption Related To Integral Al Melt Preparation And Supply

With the increase of energy saving and environmental pressure, it has become the only choice of human civilization to push manufacture industry to progress in the direction of energy conservation and environment protection via technology development.The present study was focused on a comprehensive comparison of energy consumptions in a Al casting factory using both traditional melt preparation and supply process(characterized by its separation of melting, melt purification and pouring operations) and the integrated melt preparation and supply process(characterized by the integration of melting, melt purification and pouring operations in one furnace), followed by identification of energy input and output contributions. Finally, potential technical innovations for energy saving for both processing routes were proposed and the energy saving mechanism of the integrated route was determined.The main conclusions of the present study are summarized as follows:(1) The thermal equilibrium of Al alloy melt preparation and supply equipment are established on the basis of analysis and calculation. The heat input consists of heat of metal oxidation, physical heats of preheated air and fuel, and fuel combustion chemical heat. The heat output items include: melt effective heat absorption, heat loss of flue gas, the radiation heat loss of the furnace wall, radiation heat loss of furnace wall opening and opened furnace door, heat loss through poorly sealing of door and other connecting parts, the heat loss of slag, and the heat loss of fuel chemically incomplete combustion.(2) As a correspondence to serious energy consumption of the traditional Al melt preparation and supply equipment, the main energy-saving measurements for melting furnace are: furnace structure and process improvement, high temperature flue-gas heat recycling technology, improving combustion and combustion control technology, and improving the insulation of lining and furnace wal.(3) The main energy-saving technical measurements can be taken on integrated furnace are: flue-gas heat recycling technology, insulation improvement of lining and furnace wall materials,and compact design to reduce the specific surface of the furnace.(4) A comparison of the energy consumption data collected on production site show that, the fuel consumption of the traditional Al melt p reparation and supply equipment was B=125 m3/h per ton Al melt, while 54 m3/h for integrated furnace, indicating a greatly decrease energy saving under same melt productivity with integrated process.(5) A comparative analysis of the energy consumption data show that the thermal efficiency of integrated furnace is 54.1%, while 21.5% for traditional Al melting furnace. The heat loss via high temperature flue-gas accounts for 22.4% of the total heat input for the traditional Al melting furnace. However, only 4.6% of heat input was discharged into the air in integrated furnace due to the temperature of the flue- gas is reduced to 150 ? in the heat-exchanger of flue-gas and air for combustion.(6) Therefore, it can be concluded that, flue-gas heat recycling is the most effective technical method that reduces not only the specific energy consumption, but also the environment impact. The integration of melting, purification and pouring into one furnace not only simplify the melt preparation and supply equipment and processing management, but also reduce the labor need and provide the possibility of labor free processing.