STUDY INFLUENCE THE DESIGN ОXYGEN LANCE HEAD ON THE RESULTS OF CONVERTER MELTING WITH SCRAP PREHEATING

Abstract

The results of calculation of energy efficiency of the variant of technology of converter smelting with preliminary heating of scrap metal in the unit due to burning of solid fuels in modern raw material conditions of the metallurgical enterprise of Ukraine are presented. A critical analysis of the variant of converter smelting technology with the use of preheating of an increased amount of scrap metal in the charge containing briquettes of steel chips in the unit, before pouring processing iron. According to the results of the calculation of the efficiency of use of different types of fuel used for preheating of scrap metal in the unit, the rational type and technology of its use in converter smelting are determined. A direct connection between the chemical composition of briquettes, the level of their preheating and the share in the metal charge on the energy efficiency of the converter process and their chemical heat content has been established. The nature of the temperature distribution in the volume of briquettes from steel shavings, which are a part of the metal charge, is taken into account when they are preheated by oxidation of coal with oxygen supplied through the nozzles of the standard lance. A method for calculating the change in energy consumption of scrap metal during its preheating, taking into account the content of elements in the briquettes and the level of heating.
 The energy consumption of the converter process with preheating of the metal charge increases in proportion to the level of contamination of briquettes from steel chips with non-metallic inclusions. According to the calculations when heating briquettes by 100—800 degrees in the converter, the increase in energy consumption of the converter process is from 60 to 630 MJ / t and from 445 to 1000 MJ/t for contamination of briquettes with non-metallic inclusions of 2.47 and 7.87 % by weight in accordance. With the reduction of briquette contamination, the efficiency of preheating of the metal charge increases. The share of the impact of the level of briquette contamination on the overall energy efficiency of the converter process is on average 0.3 % of the total energy savings of 1.91—1.92 GJ / t, which is achieved by increasing the share of scrap metal in the charge.