About economic management of heating metal in industrial furnaces

The problem of optimal control of metal heating in industrial furnaces is considered. Data are analyzed both for the author's own research and for the data of other literary sources. The principle of economical management of metal heating is pointed out, and its validity is discussed. This takes into account both the utilization of the heat of the combustion products within the furnace proper and the loss of heat through the masonry. It is noted that there are works in the literature in which, unfortunately, the rewriting of long-known conclusions and results on optimal control continues, and the regularity of economical heating is allegedly re-established. Recommendations are given on the implementation of the principle of economical management in the framework of the automated process control system (ACS TP) of methodical furnaces. The features of the algorithm proposed by the author for calculating the settings (tasks) for temperature regulators in the zones of methodic furnaces are described. Calculation always begins with the furnace's kiln area. The implementation of the algorithm provides such a temperature distribution over the zones of the furnace, at which the desired quality of heating of the preforms is achieved, but the region of the highest temperatures of the working space is displaced as far as possible to the end of the furnace. Typical graphs of the temperature distribution over the zones of the furnace, obtained using the calculation algorithm, are given. It is emphasized that the process control system must contain a subsystem controlling the actual temperature of the slabs, which should be an instrumental - a calculation subsystem.