Objetivo The aim of the project is to reduce the electrical consumption in the melting process of the scrap in an electric arc furnace by means of a combined system of computer and automatisms which regulates the energy supply in each step of the melting operation and in each zone of the furnace operating independently each electrode.This project was presented to be installed in a special steel plant producing 200,000 tons per year, with an estimated energy saving of 15 of 20 Kwh/t.The system generates additional savings in the reduction of refractories and electrodes consumption due to the reduction of the tap to tap period.The system has been installed in the factory in December 1988.During January and February 1989, work was carried out in the melting shop in order to adapt the system to the specific plant characteristics and to obtain an integral use of he whole possibilities of the system.From the beginning of March 1989 the ARMS MARK II is performing in optimal operating conditions and the results obtained allow to assure that the estimates of energy previously foreseen will be widely surpassed.The results obtained have been, per ton of liquid steel : Electric Arc Ladle EAF + Furnace Furnace LF ____________ _______ _____ kWh Nm30 kWh kWh 2 ________________________________________________________ 1988 average 464 34,272 536 January 1989 465 33,5 68 533 February 1989 466 34 75 541 March 1989 425 33,8 65 490 April 1989 416 32,9 65 481 It means that an energy saving of 536-481 = 55 kWh/ton of liquid steel has been achieved. It is expected that this energy saving will be maintened or surpassed.Additional savings coming from the reduction of refractories and electrodes consumptionas well as metalic yield increasing have been detected.The basic principle of the project lies in the fact that fundamental values such as the reactance, the input power and the power factor show variations during the operation in an electric arc furnace. And these values, as is well known, condition the efficiency of the power used and the time needed to perform the whole melting process.On the other hand, the behaviour of an electric arc furnace during the melting process is an individual matter pertaining to each one of the furnaces. In other words, the real dynamic behaviour of a specific furnace cannot be deduced, with sufficient accuracy, from the theoretical electric characteristics : an in process measurement of the different values must be done.The problem now is how to get the measurements in order to use them to perform the melting process minimizing the power consumption.The method of measurement of secondary voltage and current is one of the most innovative features included in this demonstration project and differentfrom other systems now operating in the shops. This method is based on the works developed by Dr. Inagaki, summarized in the paper presented at the 9th UIE congress held in Cannes in 1980. The results obtained show that : - approximate reactance factor derived from the measured mean electrical values to be as good as that obtained from corresponding effective values,- accordingly, there is a possibility of employing a simpler measuring device (use of mean values) for on-line control.With this special measurements method, the true electric characteristics of the furnace are grasped and so the real dynamic behaviour of the furnace is known.The functions the system does are :. Monitoring :Knowledge of the means per minute of the different operational parameters of the furnace allows an exact follow up of the process in all its stages.. Melting control :The system controls the secondary current of each phase in order to obtain a minimum energy consumption in each stage.. Demand control :The system controls the energy consumption in all the plant optimizing it during each demand cycle. . Data logging :The system displays and logs the data needed to operate the furnace and to optimize the input power pattern.. Optimization of the input power pattern :With the information recorded on the tape, periodical analysis can be made in order to identify optimized input power patterns based on evolution of the internal parameters of the furnace itself and other external factors. Programa(s) ENG-ENDEMO C - Programme (EEC) of demonstration projects and industrial pilot projects (EEC) in the energy field, 1985-1989 Tema(s) 3.4 - INDUSTRY Convocatoria de propuestas Data not available Régimen de financiación DEM - Demonstration contracts Coordinador INGENIERIA Y SISTEMAS SIDERURGICOS S.A.INSERIALE Aportación de la UE Sin datos Dirección ARTAZA 7 48940 LEIOA España Ver en el mapa Coste total Sin datos
