State-of-the-art plants for drying and high-temperature heating of ladles

Abstract

The Stal'proekt Institute has developed state-of-the-art plants for drying and high-temperature heating of steel-teeming ladles. Two new plants for drying tundish ladle lining have been designed for machine No. 6 for continuous billet casting at the Oskol'skii Electrometallurgical Works. Plants for drying and heating 30-ton teeming ladles to a temperature of 800°C and for high-temperature heating of ladle lining (1200°C) have been designed for a currently constructed metallurgical works. All these plants recover flue gas heat and use it for heating air supplied for combustion, thus decreasing the consumption of fuel. The process of drying and heating of lining is analyzed using a mathematical model developed at the institute. The plants are equipped with automatic control systems controlling the temperature schedule of drying and heating the lining. The specified plants ensure cost-effective operation in an automatic mode The Stal'proekt Institute has designed state-of-the-art plants for drying and high-temperature heating of teeming ladles. The use of flue gas heat, modern burners, and automation instruments provide for cost-effective and safe performance of these plants in different operating modes.The lining division of the electric steel-melting shop of the Oskol'skii Electrometallurgical Works (OEMW) at the moment has four plants for drying tundish ladles that cast steel for machines for continuous billet casting Nos. 1 -5. In connection with the construction of a new machine for continuous billet casting (No. 6), two additional plants (Nos. 5 and 6) are required to dry the lining of tundish ladles produced by Concast (Switzerland). The design of these drying plants have been developed at the Stal'proekt Institute.The new plants are located on two sides of the four existing tundish-drying stands and use the existing fume duct to deflect flue gases.The main difficulties in designing were related to the existence of a common flue gas duct for six plants, since it was necessary to provide safe gas combustion, cost efficiency, and compliance with preset lining-heating schedules for the plants simultaneously operating in different working regimes. The fuel flow rate and the type of burners were chosen using a mathematical model developed at the institute, which, in addition to heat analysis, also performs hydraulic analysis of the gas system.We have developed a mathematical model for calculating the process of tundish ladle lining by gas burners in accordance with a preset drying schedule, taking into account that air used for natural gas combustion is heated in the loop recuperator using flue gases exiting from the tundish ladle.In the mathematical sense, the model is based on a combined solution of a system of integral and nonstationary differential equation, describing the following thermophysical processes occurring in the volume of the tundish ladle and in its lining; -heat exchange by radiation between all inner surfaces of the tundish ladle and the gaseous space inside the ladle, taking into account the re...