Improving certain units for automatic measurement and control of blast furnaces

The blast furnaces of the Nizhne-Tagi lsk Metal lurgical Combine work with increased gas pressure under the throat with high temperature of the hot blast and constant moisture content. The furnaces are equipped with modern measuring apparatus which indicates sufficient accuracy the thermal state and the state of operation of the furnace and makes i t possible to take the necessary steps to prevent deviations from the normal conditions. Furthermore, the furnaces have automat ic devices to control the temperature of the air heaters, the temperature of the hot blast, the moisture of the blast, pressure of the gas under the throat and the pressure of the pure gas fed to the air heaters. Efficient working of the measuring and control apparatus assists the engineers of the combine in ach ieving good quality and economic operation. In order to improve the instruments and the automat ic regulators cer tain units for measuring individual features and arrangments for automat ic control were redesigned and improved. This redesigning took into account the requests of the operating personnel. Measuring the Temperature of the Hot Blast. The temperature of the hot blast at the Nizhne-Tagilsk Metal lurgical Combine is mainta ined at 850-900 ~ and is measured by a he rmet ica l ly sealed inertialess ch romel -a lumeI ~ e r m o c o u p l e (Fig. 1). This design gives a more durable thermocouple and increases its sensitivity. The thermocouple can be replaced without removing the blast. For this purpose, i t is necessary to open