Obiettivo The aim of the project is to save electrical power used for melting scrap and metal during steel production in an electric-arc furnace. This will be achieved by using the heat of the post combustion of CO-gas within the furnace to pre-heat the scrap metal. A unique feature of the project is that the scrap is pre-heated in a manner which avoids environmental pollution from organic substances.With the employment of the oxygen nozzles, energy balance advantages were achieved in different operating programs, these being reflected particularly by significant decreases in the consumption of electrical power. The costs incurred as a result of the increase in chemical energy input were readily offset by the reduced input requirement for electrical power and metallurgically effective oxygen. The results have shown that the post-combustion of the CO-containing gas which evolves during scrap meltdown will bring advantages both in the energy balance and on the cost efficiency side. Of particular significance is the fact that no additional carbon beyond the volume required for the melting process needs to be fed into the furnace. That means, that no additional CO2 was built by the process.L% The results have proved that, during scrap meltdown, even without the addition of carbon (second and third scrap bucket) sufficient CO can be post-combusted through the input of oxygen to produce a return in the form of savings in electrical power and increases in productivity. Good success is expected from the envisaged system of controlling the oxygen input as a function of the exhaust gas temperature and the associated temperature gradient.L% Measurements of the exhaust gas concentration have shown that, on average, CO volumes evolve which can only be efficiently combusted with employment of a third oxygen nozzle. It is firmly expected that this will lead to further energy savings and an additional increase in productivity. Employment of the demonstration facility under production conditions took place without fundamental problems occurring.L%The purpose of the project described in the original proposal was to utilize the physical heat of the electric arc furnace gas for preheating the charge material. In contrast to conventional processes for scrap preheating, the gas arising from this process was to be completely combusted at temperatures above 800 deg. C and the scrap preheated to temperatures around 400 deg. C. However, owing to changes in the company's product mix, the percentage of scrap available for preheating in this way was reduced, so placing in question the possibility of operating the envisaged facility economically.A new concept was devised involving the injection of air, heated within a regenerative system to 1200 deg. C, via a nozzle arrangement into the UHP furnace. It was assumed that the improved gas permeation of the scrap charge would produce more effective post-combustion of the CO within it. Problems with the static structural design of the furnace meant that this concept too could not be pursued further.Consequently, instead of hot air, it was decided that oxygen should be injected into the furnace via oxygen nozzles. Through the employment of three oxygen nozzles in the UHP furnace of Hamburger Stahlwerke GmbH, oxygen was thus to be applied for the post-combustion of the CO arising in the furnace interior. The purpose lay in reducing the specific electrical power input while achieving at least the same meltdown performance of the electric arc furnace with total energy costs remaining roughly the same. Programma(i) ENG-ENDEMO C - Programme (EEC) of demonstration projects and industrial pilot projects (EEC) in the energy field, 1985-1989 Argomento(i) 3.4 - INDUSTRY Invito a presentare proposte Data not available Meccanismo di finanziamento DEM - Demonstration contracts Coordinatore HAMBURGER STAHLWERKE GMBH Contributo UE Nessun dato Indirizzo DRADENAUSTRASSE 23 21129 Hamburg Germania Mostra sulla mappa Costo totale Nessun dato
