Blast furnace gas pressure control - at blast furnace mouth using a logic system to control gas turbines in parallel with the gas main throttling device (SW251076)

摘要

System for controlling the gas pressure at the top of the super-power blast furnace comprises a blast furnace gas main incorporating a throttling device in parallel with two, pref. three, gas turbines each with a pre-heater on its inlet side. The turbine exhaust pipes re-unit and join the blast furnace main passing to the consuming equipment. The throttling device has regulating butterfly valves with rotary operators. These valves operate switches when they reach their limiting closure position. One valve also operates a switch when the butterfly is fully open. The turbines are all of similar design. Each turbine has a regulating butterfly with a rotary operator energised from a logic unit in common with the rotary operators belonging to the throttling device and the other turbines. When fully open the butterfly operates one switch while when fully closed it operates two other switches at predetermined rates of flow. A further butterfly is normally open but can close to operate a switch in case of an emergency. A pressure-senser supplies a signal to the one-way regulator, the output from which is supplied to a pre-set display on the controllers console and to the logic unit. The system gives increased production of electricity (5-10%) and greater precision in the control of blast furnace gas pressure at the mouth of the blast furnace.