Development of Efficient Cooling Regimes for the Lining of a Ferroalloy Production Casting Ladle

The refractory lining of high-temperature aggregates determines the duration of their operation before major repairs. The ability to retain technological material within the aggregate’s working area is the main factor for its continued operation. The analysis shows that the main reason for the destruction of the lining of ferroalloy production casting ladles is the occurrence of thermal stresses in the processes of heating and cooling the lining. When the stresses exceed the ultimate strength of the refractory material used, the material is destroyed. The greater the magnitude and duration of the excess thermal stresses, the faster the lining destruction occurs. Streamlining thermal regimes is the most low-cost and sufficiently effective way to increase the durability of linings. The development of lining heating and cooling regimes can be carried out on the basis of determining the thermal stress state by calculating the maximum permissible heating rates. The developed regimes allow for working at speeds at which the resulting stresses do not exceed the ultimate strength of the refractory materials. The aim of this study is to develop efficient cooling regimes for the lining of a ferroalloy production casting ladle from the standpoint of the resulting thermal stresses. A method for determining the thermal stresses in the lining has been developed and implemented using Microsoft Excel. This facilitates the use of the developed methodology in production without the need for special skills on the part of operating personnel. Using the developed methodology, the cooling schedules for the lining of ferroalloy production ladles were improved. To reduce temperature unevenness across the lining cross-section, a decision was made to initially heat the outer surface of the lining and cool the inner surface of the lining. Heating the outer surface can be achieved by using the heat of combustion of the ferroalloy gas or the heat of the exhaust gases from the stand for drying and heating casting ladles. Cooling the inner surface of the lining can be achieved by natural convection. The result of the development and implementation of an efficient cooling regime is a reduction in thermal stresses to the required level throughout almost the entire cooling process.