Obiettivo To develop and examine a method for preheating scrap for use in electric arc furnaces using waste gases. The furnace had a capacity of 130t of steel. An energy saving of approximately 43 kwh/t of liquid metal is to be achieved by preheating the scrap to temperatures of between 200 deg.C and 300 deg.C corresponding to an annual saving of 925 TOE at project level. It is also planned to reduce the tap to tap time thereby increasing productivity. An 8% reduction in graphite electrode consumption is expected. The proposed method is to be investigated and tested in an aluminium smelting plant operated by the BSC in Tinsley Park Sheffield.The preheating station was integrated into the existing waste gas system of the furnace Z in accordance with the time schedule. For this purpose, comprehensive and difficult detailed solutions had to be developed and implemented for the chamber, the movable chamber hood, the hydraulic facilities and the modification of the existing scrap baskets. Simultaneously techniques were investigated relating to the mode of operation of the plant, and corresponding control systems including the necessary measuring systems were installed. First tests indicate a total saving of 24.6 kWh/t of molten metal. The sealing of the preheating station posed particular problems, leading to air ingress and changes in the pressure conditions in the waste gas system. For operational reasons, it was only possible to preheat one scrap basket at a time. Due to these unsatisfactory results, the sealing system hood/chamber was changed and the scrap baskets were modified. These measures reduced costly maintenance work and improved the performance of the pre-heating station.The plant was put into production operation and operating procedures were developed. After one year of operation, the best results were obtained by heating first baskets only at 90 % availability. The overall savings achieved were 10.0 kWh/tonne of scrap (total) charged to the furnace and a 2 % saving in electrode graphite. The plant has since been closed and demolished.The principal component in the proposed process is a so-called scrap preheating station. This will be integrated into the existing waste gas system of the furnace in such a way that no influence is to be expected on the drawing conditions of the furnace. The preheating station consists of a plenum chamber, which is charged with scrap baskets via a crane. The chamber is subsequently closed by means of a moveable hood. The fumes are fed in via the hood and removed at the base of the chamber. The design of the fuel duct including the necessary suction ventilators must guarantee satisfactory operation of the furnace. Automatically controlled dampers will ensure the exact regulation of the pressure conditions in the entire waste gas system. Burners fired with coke oven gas will guarantee the combustion of safety-relevant combustible gases in the fumes. Originally the entire project was to be completed in approximately 1,5 years. In the event of a successful demonstration, the transferof the process to many similar furnace systems could lead to a significant energy saving at community level. Programma(i) ENG-ENALT 1C - Programme (EEC) of financial support for projects to exploit alternative energy sources, 1979-1984 Argomento(i) 1.6 - INDUSTRY Invito a presentare proposte Data not available Meccanismo di finanziamento DEM - Demonstration contracts Coordinatore British Steel plc Contributo UE Nessun dato Indirizzo Moorgate S60 3AR Rotherham Regno Unito Mostra sulla mappa Costo totale Nessun dato
