GB678530A - Improvements in or relating to blast furnaces and like shaft furnaces - Google Patents

Abstract

678,530. Blast furnaces. LEONE, O. J., and LEONE, D. P. Feb. 13,1950, No. 3677/50. Class 72 [Also in Group XXXV] In a method of controlling a blast furnace the static pressure is measured near the bottom and near the top of the'stack and the pressure drop is controlled'to a value below that at which the furnace has a tendency to generate slipping conditions by selective variation of the temperature, pressure and rate of flow of the gases at the top and bottom of the stack. As shown, the static pressure may be measured at point 11 in the blast pipe and at point 12 in the exhaust pipe, these pressures being fed into a controller 10, which may or may not be recording, and which operates a valve 19 in the exhaust pipe to control the static pressure in the stack. The temperature of the blast may be measured by a thermostat 30 in the blast pipe, controlling the amount of air which byepasses an air heater 7. The points of measuring the pressure may be in the stack and the blast pressure may be regulated by varying the speed of the fan or by a valve in the blast pipe, Fig. 2, (not shown). The temperature of the exhaust gas may be controlled by a thermostat operating a water spray at the top of the stack, Figs. 2 and 3, (not shown). The temperature and pressure readings may be co-ordinated giving a very fine control of the static pressure in the stack. The charging bell controls may be connected to the controller so that the latter does not operate during charging periods.