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Show 1 1. Introduction Sumitomo metals developed Oxygen Jet Burner and Oxygen enrichment Burner in order to quickly clean metal and slag stuck to the surface of a converter, a ladle, a torpedo, a RH degasser l)2)and other devices. With the new type of burner, high speed melting and cutting of metal and slag was achieved. When scrap is melted in an AC Electric arc furnace, cold spots exist in it and increase the melting time of the scrap. An 80ton AC Electric arc furnace in Wakayama steel works was installed with a conventional oxygen burner to heat these cold spots, but that conventional burner didn't have enough power to melt scrap and it was not durable. In order to overcome these problems, the developed Oxygen Jet Burner was installed on the furnace one by one:,). This new type of burner accelerates the melting of scrap in the cold spots. As a result, compared with the conventional burner operation, the Oxygen Jet Burner has decreased processing time by ll%(10min) , reduced energy consumption by 9%(electricity 57KWh/t), and in addition, the new burner is more durable, requiring less maintenance. 2. Development of Oxygen Jet Burner 2. 1 Outline of test to develop the burner In order to quickly clean metal and slag stuck to the surface of a converter, a ladle, a torpedo, a RH degasser and other devices using a burner, the melting and the cutting capability of the burner needed to be increased. As shown in Fig. 1, the test compared melting and cutting speed of metal and slag samples using different kinds of burners, such as a nozzle mix type and a pre mix type. As a result, the Oxygen Jet Burner was developed. As shown in Tab. 1, this new type of burner was formed by adding a special nozzle through which oxygen is blown at high velocity , higher than the conventional oxygen burner. Phot. 1 shows examples of burner flames. The developed burner has the pointed flame. Sample Burner ':•::':.W~~ * Samples : Metal and slag stuck to the surface of a converter, a ladle, a torpedo and other devices Fig. 1 The test method of a burner |