CA1109123A - Control system for an installation utilizing pressure energy of outgoing blast-furnace gas - Google Patents

Abstract

CONTROL SYSTEM FOR AN INSTALLATION
UTILIZING PRESSURE ENERGY OF
OUTGOING BLAST-FURNACE GAS
Abstract of the Disclosure A control system according to the invention has a number of control units, namely: a control unit for checking the installation for start-up readiness, a control unit for starting the installation, a control unit for synchronizing the electric-generator frequency and the power-line frequency, a control unit for increasing load of the gas turbine, a con-trol unit for monitoring the heating of blast-furnace gas, a control unit for shutting down the installation, a control unit for filling and emptying the installation, these units being appropriately interconnected. The proposed control system makes it possible to achieve fully automatic control of the installation intended for utilizing the energy of the outgoing blast-furnace gas pressure, to improve reliability thereof, and to prevent damage to the equipment and hazards to the supervisory personnel.

Description

The present invention relates to control systems, and more particularly to a control system for an installation utilizing the pressure energy of outgoing blast-furnace gas, which is intended for use mainly in ferrous metallurgy.
The installation is basically a gas turbine driving an electric generator complete with necessary controls and oper-ative devices incorporated therein, connected in parallel with a throttle unit of a blast furnace, and also provided with necessary power-driven valves and a special gas heater for heating blast-furnace gas passing to said turbine.
With construction of new giant blast furnaces and rising cost of electric power, need has arisen for utilization of the abundant energy of pressure of outgoing blast-furnace ; gas by means of special installations using gas turbines.
Such installations are efficient in operation only if fully auto~ated.
Otherwise, round-the-clock attendance of such an installation should be carried on by special personnel which, for the most part of their time, is used inefficiently. This personnel must be highly skilled, having in mind responsibility of their job involving the running of an installation using a toxic and explosive gas, a coordinated operation thereof with such a complex plant as a blast furnace, a continuous process of utilization of blast-furnace gas, a complex adjust-ment procedure when the blast furnace is temporarily changed over to operation at lower pressure of gas therein and then ~7-,n~ --2--~$~2~
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back to normal operating conditions, and also the start-up and shut-down of the installation. However, even highly skilled personnel cannot completely exclude some faults, which may have serious consequences.
Fully automatic control of the installation makes it possible to ensure the correct performance thereof and the required sequence of a great number of complex and interconn-ected operations, and to exclude the need for additional per-sonnel. Performance of the equipment as a whole is thereby ~- -made substantially more-reliable which is very important for the blast furnace equipped with a gas-utilizing installation.
The development of automatic control for a gas-utilizing installation involves the solution of a number of problems. It is, first of all, to ensure the correct sequence of operations during start-up, shut-down and change-over from one operating condition to another, and to exclude the formation of explosive gas mixtures and some other faults which may result in contamination of the atmosphere with toxic blast-furnace gas.
There is known in the prior art a control system for a gas-utilizing installation. Such a system is disclosed in Japan Patent No 49-320~4, 23 March 1974. This system is characterized in that an installation for utilizing blast-furnace gas has a gas turbine placed in parallel with throttle valves, and a valve controlling the delivery of gas to the gas turbine is opened or closed by remote control depending on the gas flow rate. The gas turbine load is determined by - . .

2~ t the extent of the control valve opening. The pressure of gas under the blast furnace top is atuomatically adjusted by a separate device for controlling the throttle valves.
When the quantity of the released gas drops because of reduced load of the blast furnace, i.e. during a short-term changeover of the blast furnace to operation at a reduced gas pressure, a suitable pressure regulator develops a signal which is used to close,the control valve at the inlet of the turbine.
Under normal operating conditions, the flow rate of blast-furnace gas exceeds the specified value, and the pressure regulator produces a signal to fully open said control valve.
The pressure of gas under the blast furnace top is regulated with the aid of the throttle valves. The shut-down of the turbine causes automatic closure of an emergency shut-off valve mounted at the inlet of the turbine, and instant complete closure of the control valve. At the same time, the throttle valves are instantly opened.
This system is not connected automatically with the control system of the gas-utilizing installation, which makes it necessary to have special personnel to run it. That also does not exclude faults, which may cause serious damage to the equipment and create hazards to the personnel by exposing them to a toxic explosive furnace gas.
There is also known a control system for an installation utilizing the energy of pressure of outgoing blast-furnace gas, -,, - .~ -: -- - ~

comprising a control diaphragm gate and a closing diaphragm -~
gate, both mounted on a gas turbine which is placed in parallel with a throttle unit of a blast furnace. The turbine is used to rotate an electric generator provided with a power-driven ventilator for its cooling. There is also provided an ~iling system with an oil pump, for both the turbine and the generator as well as a system for regulating rotational speed of the turbine rotor with a rotor-speed selector, connected to said control and closing diaphragm gates. The control system also includes a device for converting input signals coming from a regulator of gas pressure under the blast-furnace top, which device is connected to the inputs of said rotor-speed regulating system, a switch of said electric generator with a set of signalling and interlocking contacts, used for con-necting and disconnecting the generator to and from a power - line, a device for synchronizing the rotor rotational frequency and the power-line frequency, a first and second outputs thereof being connected, respectively, to an output of said electric generator and to an a.c. power line, and the first output of the synchronizing device being also connected to said switch of the generator. The control system further in-cludes a first sensor responsive to gas temperature at the inlet of the turbine placed in a furnace-gas conduit downstream of a gas heater introduced in the installation and provided with an ignitor means, said gas heater being connected with ~r~ 3 an input of a temperature regulator for a furnace gas passing to the turbine, a second sensor responsive to gas temperature placed at the inlet of the gas turbine, valves provided with electric drives therefor and placed in conduits for the delivery and discharge of blast-furnace gas to and from the gas-utilizing installation, in conduits for the delivery of air and gaseous fuel to the gas heater, in a con-duit for the delivery of inert gas to the installation, and in a conduit for the discharge of the contaminated inert gas from the installation (cf., for instance, the "Stal" magazine, ~o. 7, 1966, pp. 666-669).
This system provides for remote control of the valves in the conduits of the installation and also of the auxil~ary devices of the gas turbine and generator during their start-up and shut-down operations. The control system includes automatic regulation, interlocking, and protection from an accidental drop of the furnace-gas pressure and an accidental rise of furnace gas temperature in excess of the specified limit.
The system also provides for automatic shut-off of the air delivered to the gas heater upon a drop in the furnace-gas pressure.
The aforesaid system is not connected with a control system of the installation used during start-up, shut-down and changeover of the blast furnace to operation with reduced gas pressure. During those transitional operating conditions the ~Y --6--syste~ requires the attendance of the operator and does not prevent a possible faulty sequence of operations, which may result in the grave consequences described hereinbefore.
It is, therefore, an object of the present invention to provide fully automatic control for an installation utiliz-ing the energy of pressure of outgoing blast-furnace gas.
In accordance with a specific embodiment of the invention, a control system for an installation utilizing the energy of pressure of outgoing blast-furnace gases comprises: an electric gene ator with a power-driven ven-tilator, a ga~ turbine having a rotor, used to rotate said electric generator; an air-cooling system for said electric generator; an oiling system for said gas turbine, having an oil pump, the system being also used for oiling said electric generator; a control diaphragm gate mounted on said gas tur-bine; a closing diaphragm gate mounted on said gas turbine;
a throttle unit placed in parallel with said gas turbine;
a system for regulating rotational speed of said gas-turbine rotor, said system being connected to said control and closing diaphragm gates, a selector of rotational speed for said rotor, the selector being part of said speed-regulating system; a regulator of pressure of blast-furnace gas under the top of the blast furnace; a device for converting input signals re-ceived from said furnace-gas pressure regulator, said device being conn~cted to said throttle unit and to said rotor-speed regulating system; a switch for connecting and disconn-ecting said electric generator to and from an a.c. power line, said switch having a set of signalling and interlocking contacts; a device for synchronizing the rotor rotational frequency and the power line frequency, said synchronizing device having a first input connected to an output o~ said ~.~
~. --7--1~D$~:~3 electric generator, a second input connected to ~aid power line, and a first output electrically connected to said switch of said electric generator; a conduit for the delivery of blast-furnace gas to said gas turbine; a gas heater mounted on said conduit for the delivery of blast-furnace gas to said gas turbine, said gas heater being provided with an ignitor; a regulator of temperature of the blast-furnace gas delivered to said gas turbine, first sensor responsive to temperature of blast-furna^e gas ahead of said gas turbine, said sensor being located on said conduit for the delivery of blast-fur-nace gas to said gas turbine downstream of said gas heater and connected to the input of said furnace-gas temperature re-gulator, a second sensor responsive to temperature of blast furnace gas ahead of said gas turbine: a first valve, mounted in said conduit for the delivery of blast-furnace gas to the installation; an electric drive for said first valve, a conduit for the discharge of blast-furnace gas from said installation: a second valve, mounted on sa.id conduit for the discharge of blast-furnace gas from the installation; an electric drive for said second valve; a conduit for the del-ivery of air to said gas heater- a third valve, mounted in a conduit for the delivery of air to said gas heater: an elec-tric drive for said third valve, a conduit for the delivery of gaseous fuel to the ignitor of said gas heater; a fourth valve mounted in said con*~it for the delivery of gaseous fuel to the ignitor of said gas heater; an electric drive for said fourth valve, a conduit for the delivery of inert gas to said installation, a fifth valve, mounted in said conduit for the delivery of inert gas to the installation, an electric drive for said fifth valve; a conduit for the discharge of the contaminated inert gas from said installation, a sixth $~

valve, mounted in said conduit for the discharge of the con-taminated inert gas from the installation an electric drive for said sixth valve: a conduit for the delivery of air to said ignitor of said gas heater, a seventh valve, mounted in said conduit for the delivery of air to said ignitor, an electric drive for said seventh valve; a control unit for checking the installation for start-up readiness, having a number of inputs and outputs, a sensor responsive to position of said third valve, producing a signal indicative of its being closed, which sensor is connected to a first of said inputs of said readiness control unit- a sensor responsive to position of said seventh valve, producing a signal indicative of its being closed, which sensor is connected to a second of said inputs of said readiness control unit; a sensor responsive to position of said fourth valve, producing a signal indicative of its being closed, which sensor is connected to a third of said inputs of said readiness control unit; a sensor responsive to air pressure ahead of said third valve, producing a signal indicative of the air pressure being within its operative limits, which sensor is connected to a fourth of said inputs of said readiness control unit; a sensor responsive to air pressure ahead of said seventh valve, producing a signal in-dicative of the air pressure being within its operative limits, which sensor is connected to a fifth of said inputs of said readiness control unit, a sensor responsive to gaseous-fuel pressure ahead of said fourth valve, producing a signal indic-ative of the gaseous-fuel pressure being within its operative limits, which sensor is connected to a sixth of said inputs of said readiness control unit; a sensor responsive to oil level in the oiling system of said gas turbine, producing a signal indicative of the oil level being within its operative limits, ., ~`P~$~

said sensor being connected to a seventh of said inputs of said readiness control unit, a sensor responsive to position of said closing diaphragm gate, prodlcing a signal indicative of its closure, which sensor is connected to an eighth of said inputs of said readiness control unit: a sensor res-ponsive to position of said control diaphragm gate, producing a signal indicative of its closure, which sensor is connected to a ninth of said inputs of said readiness control unit:
a sensor responsive to position of said rotor-speed selector, producing a signal indicative of its initial position, which sensor is connected to a tenth of said inputs of said readiness control unit; a sensor responsive to position of said device : for converting input signals received from said regulator of gas pressure under the blast-furnace top, producing a signal indicative of said converting device being in its initial position, which sensor is connected to an eleventh of said .~ inputs of said readiness control unit, a start-up control unit having a number of inputs and outputs, a first input of said start-up unit being connected to a first output of said readiness control unit, a sensor responsive to oil pressure in said oiling system of said gas turbine, producing a signal indicative of the oil pressure being within its operative limits, which sensor is connected to a second of said inputs of sald start-up control unit; a sensor responsive to position of said first valve, producing a signal indicative of its open-ed position, which sensor is connected to a third of said in-puts of said start-up control unit, a sensor responsive to position of said first valve, producing a signal indicative of its closed position, which sensor is connected to a fourth of said inputs of said start-up control unit, a sensor responsive to air pressure in said cooling system of the :~ . . , electric generator, producing a signal indicative of the air pressure being of a specified value, which sensor is conn-ected to a fifth of said inputs of said start-up control unit, a sensor responsive to rotational speed of the rotor, pro-ducing a signal indicative of the rotor rotational frequency reaching a value roughly equal to the electric~generator synchronizing frequency, which sensor is connected to a sixth of said inputs of said start-up control unit, a first of said outputs of said start-up control unit being electrically ~0 connected to said oil pump; a second of said outputs of said start-up control unit being electrically connected to said electric drive of said first valve: a third of said outputs of said start-up control unit being electrically connected to said power-driven ventilator~ a fourth of said outputs of said start-up control unit being electrically connected to said rotor-speed selector: a fifth of said outputs of said start-up control unit being electrically connected to a third input of said synchronizing de~vice, a control unit for synchronizing the electric-generator Erequency and the power-line frequency, said unit having a number of inputs and outputs; a first of said inputs of said synchronizing control unit being connected with a sixth of said outputs of said start-up control unit, a second of said inputs of said synchronizing control unit being connected with said first signalling and interloc~ing contact of said switch for said electric generator, which con-tact emits a signal indicative of the electric generator being connected to the power line, a sensor responsive to position of said rotor-speed selector, producing a signal indicative of the selector being shifted to its extreme position for increased rotor speed, which sensor is connected to a third of said in-puts of said synchronizing control unit, a sensor responsive ~. ~

to rotational speed of the rotor, producing a signal indicative of the minimum rctor speed at which the elec~ric-generator f~^~uency can be shychroni7~ed with the power line frequency, which sensor is connected to a fourth of said inputs of said synchronizing control unit; a first of said outputs of said synchronizing control unit being connected to said rotor-speed selector to increase rotational speed of the rotor of said ~as turbine, a second of said outputs of said synchron-izing control unit being connected to said rotor-speed selector to reduce rotational speed of the rotor of said gas turbine;
a control unit for increasing load of the gas turbine, said unit having a number of inputs and outputs; a first of said inputs of said load-increase control unit being connected with a third of said outputs of said synchronizing control unit, a sensor responsive to the flow rate of furnace . gas, producing a signal indicative of the maximum rate of gas : flow through said gas turbine without operating the gas heater, which sensor is connected to a second of said inputs of said load-increase control unit, said sensor responsive to position of said rotor-speed selector, producing a signal indica~ive of the selector being shifted to its extreme position for increased rotor speed, said sensor being connect-ed to a third of said inputs of said load-increase control unit; a first of said outputs of said load-increase control unlt being connected to said -.-otor-speed selector, a control unit for controlling the heating of blast-furnace gas, said unit having a number of inputs and outputs; a first of said inputs of said gas-heating control unit being connected to a second of said outputs of said load-increase control unit, a second of said inputs of said gas-heating control unit being connected with a second of said outputs of said rea~iness ~s i~

control unit, a sensor responsive to the flow rate of furnace gas, producing a signal indicative of the rate of gas flow through said gas tur~ine reaching its value at which the gas heater is actuated, which sensor is connected to a third of said inp~ts of said gas-heating control unit, a sensor responsive to temperature of gas at the outlet of said ig- :
nitor, producing a signal indica_ive of the gas temperature exceeding :i.ts ignition point, which sensor is connected to a fourth of said inputs of said gas-heating control unit; a sensor responsive to position of said third valve, producing a signal indicative of its opened position, which sensor is con-nected to a fifth of said inputs of said gas-heating control unit; a sensor responsive to the flow rate of furnase gas, p -~ucing a signal indic~t;ve of the minimum rate of gas flow through the gas turbine at which the delivery of air to the gas heater is stopped, which sensor is connected to a sixth of said inputs of said gas-heating control unit, said second sensor responsive to the blast-furnace gas temperature shead of said gas turbine, producing respective signals indicative of the min-imum and rnaximum gas temperatures at which said gas heater is shut down, said sensor being provided with two outputs conn-ected respectively to a seventh and an eighth inputs of said gas-heating control unit, a first of said outputs of said gas-heating control unit being electrically connected to said electric drive of said seventh valve for its opening; a second of said outputs of said gas-heating control unit being elec-trically connected to said electric drive of said fourth valve for its opening; a third of -said outputs of said gas-heating control unit being electrically connected to said electric drive of said third valve for its opening, a fourth of said outputs of said gas-heating control unit being electrically connected to said ignitor, a ~-ifth of said outputs of said gas-heating control unit being electrically connected to said regulator of gas temperature ahead of said gas turbine for switching it "on" and "off", a sixth of said outputs of said gas-heating control unit being electrically connected to said electric drive of said seven valve for its closure, a seventh of said output of said gas-heating control unit being electrically connected to said electric drive of said ourth valve for its closure; an eighth of said outputs of said gas-heating control unit being electrically connected to said electric drive of said third valve for its closure; a control unit for changing over the regulator of gas pressure under the blast-furnace top, which is used to connect and dis-connect an output of said regulator through said input-signal converting device to an input of said rotor-speed regulating system or to an input of said throttle unit of said blast fur-nace said control unit having a number of inputs and outputs;
a first of said inputs of said changeover control unit being connected with a ninth of said outputs of said gas-heating control unit; second of sa;d inputs of said changeover control unit being connected to a tenth of said outputs of said gas-heating control unit, a third of said inputs of said change-over control unit being connected with an eleventh of said outputs of said gas-heating control unit, a fourth of said inputs of said changeover control unit ~eing connected to said sensor responsive to furnace-gas flow rate, which produces a signal indicative of the maximum rate of gas flow through said gas turbine with said gas heater being inoperative; a sensor responsive to gas temperature ahead of said gas tur-bine, producing a signal indicative of the minimal temperatureof the gas in said turbine at which said pressure regulator is - 14 ~

connected to said input of said rotor-speed regulator, which sensor is connected to a fifth of said inputs of said change-over control unit, a first of said outputs of said change- , over control unit being electrically connected to said rotor-speed selector, a second of said outputs of said changeover control unit being electrically connected to said furnace-gas :~
pressure regulator for connection and disconnection thereof through said input-signal converting device to the input of said speed-regulating system, a third of said outputs of said changeover control unit being electrically connected to said output of said furnace-gas pressure regulator for connection and disconnection thereof to the input of said throttle unit of said blast furnace; a fourth of said outputs of said change-over control unit being connected to the input of said speed-regulating system through said input-signal converting device for transmitting a signal to red~ce load of said gas turbine;
a shut-down control unit having a number of inputs and outputs;
a first of said inputs of said shut-down control unit being connected with a seventh of said outputs of said start-up control unit, said sensor responsive to position of said clos-ing diaphragm gate, prod~cing a signal indicative of its closed position and connected to a second of said inputs of said shut-down control unit; a sensor responsive to rotational speed of the rotor' producing a signal indicative of the max-imum rotor speed, which sensor is connected -to a third of said inputs of said shut-do~n control unit; a sensor responsive to oil pressure in the oiling system, producing a signal indicative of the oil pressure dropping to its minimal value, which sensor is connected to a fourth of said inputs of said shut-down .,~ ~,,. ,~ ..
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control unit, a sensor responsive to position of said first valve, producing a signal indicative of its opening position, which sensor is connected to a fifth of said inputs of said shut-down control unit:

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connected to a sixth of said inputs of said shut-down control unit, a sensor responsive to the maximum temperature of bear-ings of said gas turbine and said electric generator, which sensor is connected -to a se~enth of said inputs of said shut-down control unit, a sensor responsive to vibration of bearings of said gas turbine and said electric generator, which sensor is connected to an eighth of said inputs of said shut-down control unit, a first of said outputs of said shut-down : control unit being connected to a seventh of said inputs of said start-up control unit; a second of said outputs of said : :
: shut-down control unit being connected to an eighth of said : :
inputs of said start-up control unit; a third of said outputs of said shut-down control unit being electrically connected to the input of said rotor-speed regulating system for rapid opening and closure of said control and closing diaphrag~
gates, a fourth of said outputs of said shut-down control unit being electrically connected to said rotor-speed selector to transmit a signal thereto for its return to the initial ~; position: a fifth of said outputs of said shut-down control 20 unit being connected to a ninth of said inputs of said gas-heating control unit' a sixth of said outputs of said shut-down control unit being connected to a tenth of said inputs of said ga~-heating control unit' a seventh of said outputs of said shut-down control unit being connected to an eleventh of said inputs of said gas-heating control unit, an eighth of said outputs of said shut-down control unit being connected to a sixth of said inputs of said synchronizing control unit, .
a ninth of said outputs of said shut-down control unit being : electrically connected to said switch of said electric gen-erator, a control unit for controlling the filling and - emptying of the installation, said unit having a number of _ 16 _ '':~,F~
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inputs and outputs: a first of said inputs of said filling and emptying control unit being connected with a tenth of said inputs of said shut-down control unit; said sensor responsive to position of said first valve, producing a signal indicative of its closed position, said sensor being connected to a second of said inputs of said filling and emptying control unit a sensor responsive to position of said second valve, producing a signal indicative of its closed position, which sensor is connected to a third of said inputs of said filling and emptying control unit; a sensor responsive to position of said second valve, producing a signal indicative of its open-ed position, which sensor is connected to a fourth of said inputs of said filling and emptying control unit; a sensor responsive to position of said fifth valve, prod~cing a signal indicative of its being closed, which sensor is connected to a fifth of said inputs of said filling and emptying control unit a sensor responsive to position of said fifth valve, producing a signal indicative of its opened position, which sensor is connected to a sixth of said inputs of said filling and emptying control unit; a sensor responsive to position of said sixth valve, producing a signal indicative of its closed position, which sensor i~ ~onnected to a seventh of said inputs of said filling and emptying control unit; a sensor responsive to position of said sixth valve, producing a signal indicative of its opened position, which sensor is connected to an eighth of said inputs of said filling and emptying control unit; a first of said outputs of said filling and emptying control unit being connected to a twelfth of said inputs of said readiness control unit a second of said o~tputs of said filling and emptying control unit being electrically connected to said electric drive of said first valve for its closure a .

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third of said outputs of said filling and emptying control unit being electrically connected to said electric drive of said second valve for its closure, a fourth of said outputs of said filling and emptying control unit being electrically connected to said electric drive of said fifth valve for its closure, a fifth of said outputs of said filling and emptying control unit being electrically connected to said electric drive of said sixth valve for its closure, a sixth of said outputs of said filling and emptying control unit being elec-trically connected to said electric drive of said second valvefor its opening, a seventh of sa.id outputs of said filling and emptying control unit being electrically connected to said ~ electric drive of said fifth valve for its opening: an eighth : of said outputs of said filling and emptying control unit ; being electrically connected to said electric drive of said sixth valve for its opening. ~ ;
-; It is expedient that said control unit for checking the installation for start-up readiness should comprise a relay operative for permitting the starting of the gas heater, : 20 said relay having a feed circuit for a coil thereof, said cir-cuit incorporating a number of contacts connected in series, -namely, a make contact of the sensor responsive to position of the vaIve in the conduit for the delivery of air to the gas heater, which contact is closed upon closure of that valve, a make contact of the sensor responsive to position of the valve in the conduit for the delivery of air to the ignitor of the :
gas heater, which contact is closed upon closure of that valve, a make contact of the sensor responsive to position of the valve in the conduit for the delivery of gaseous fuel to the ignitor of the gas heater, which contact is closed upon ' :~
~ closure of that valve~ a make contact of the sensor res-: .

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ponsive to air pressure ahead of the valve in the conduit for the delivery of air to the gas heater, which contact is closed while the air pressure is within its specified operative limits, a make contact of the sensor responsive to air pressure ahead of the valve in the conduit for the delivery of air to the ignitor of the gas heater, which contact is closed while the air pressure is within its specified operative limits, and a make contact of the sensor responsive to gaseous-fuel pressure ahead of the valve in the conduit for the delivery of gaseous fuel to the ignitor of the gas heater, which contact is closed while the gaseous-fuel pressure is within its specified operative limits, a ~ake contact of said relay for permitting the starting of the gas heater forming the second output of said readiness control unit, and also a relay oper-ative for permitting the start-up of the installation, said relay having a feed circuit for a coil thereof, said circl~it incorporating a number of contacts connected in series, namely, a make contact of the sensor responsive to oil level in tne oiling system, which contact is closed while the oil level is within its specified operative limit, a make contact of the sensor responsive to position of the closing diaphra3m gate, which contact is closed upon closure of this gate, a make contact of the sensor responsive to position of the control diaphragm gate, which contact is closed upon closure of this gate, a make contact of the sensor responsive to position of the rotor-speed selector, which contact is closed when the selector is in its initial position, a make contact of the sensor responsive to position of the device for con- r ~: verting input signals coming from the regulator of gas pressure i ~:
under the blast-furnace top, which contact is closed when this device is in its initial position, a make contact of the X relay for permitting the starting of the gas heater, and a ,~ - 19 --:. :,, . i , .: :~

make contact of an output relay of the filling and emptying control unit, said contact being the first output of the filling and emptying control unit, a make contact of said relay for permitting the start-up of the installation forming the first output of said readiness control unit.
It is preferable that said start-up control unit should comprise a push-button switch "start", an automatic-start rela-~, a relay for preparing the starting of the oil pump, a time relay for stopping the oil pump, a relay for con-trolling the oil pump, a relay for actuating the electric driveto open the valve in the conduit for the delivery of blast-furnace gas to the installation, a relay for actuating the power-driven ventilator, a relay for actuating the rotor-speed selector, and a relay operative upon completion of the :
installation starting, a feed circuit for a coil of said autom- :~
atic-start relay including a make contact of said push-button switch "start", a make contact of said relay for permitting start-up connectèd in series with the preceding contact, a make ; contact of said automatic-start relay being connected in parallel with the two conta-ts, and, connected in series with all these contacts, a break contact of said starting completion relay and a break contact forming the first output of the shut-.
down control unit, a feed circuit for a coil of said relay for preparing the oil pump starting including a make contact of the automatic-start relay, a make contact of said relay . for preparing the oil pump starting connected in parallel with :; the preceding contact, and a break contact of said time relay for stopping the oil pump connected in series with these two contacts, a make contact of the relay for preparing the oil pump starting forming the seventh output of the start-up control unit, a feed circuit for a coil of said time relay for stopping ,~
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the oil pump including a make contact of the sensor responsive to position of the valve in the conduit for the delivery of blast-furnace gas to the installation, which contact is closed upon closure of that valve, an~ a make contact forming the second output of the shut-down control unit, a feed circuit for a coil of said relay for controlling the oil pump including a make contact of the relay for preparing the oil pump starting and a break contact of the sensor responsive to rotational speed of the rotor, which contact is opened when the rotor rotational frequency reaches a value roughly equal to that of the syn-chronizing frequency of the electric generator, both contacts being connected in series, a make contact of the relay for controlling the oil pump being the first output of the start-up unit, a feed circuit for a coil of the relay actuating the electric drive to open the valve in the conduit for the delivery of blast-furnace gas to the installation including a make contact of the sensor responsive to oil pressure in the oiling system of the gas turbine, which contact is closed while the oil pressure therein is within its specified operative limits, : 20 and a make contact of the automatic-start relay, both these contacts being connected in series, a make contact of said relay actuating the electric drive to open the valve in the conduit for the delivery of the blast furnace gas to the installation forming the second output of the start-up control unit, a feed circuit for a coil of the relay for actuating the power-` driven ventilator including a make contact of the sensor res-ponsive to position of the valve in the conduit for the delivery of blast-furnace gas to the installation, which contact is closed upon the opening of that valve, a make contact of said relay for actuating the ventilator forming the third output of the start-up control unitl a circuit for a coil of said ': ~

$~23 relay for actuating the rotor speed selector being connected in parallel with the coil of the relay for actuating the ventilator and including a make contact of the sensor responsive to air pressure in the cooling system of the electric generator, which contact is closed while the air pressure is within its specified operative limits, and a break contact of the start-up completion relay, both above :~
contacts being connected in series, a make contact of the relay for actuating the rotor-speed selector forming the fourth output of the start-up control unit, and a feed circuit for a coil of said relay operative upon completion of the installation start-up including two series-connected contacts, viz. a break contact of the relay for controlling the oil pump, a make contact of the relay for actuating the rotor-speed selector, and a make contact of said start-up completion relay connected in parallel with both a~ove contacts, said make contact forming the first output of the shut-down control unit being connected in series with these contacts, and make contacts of the start-up completion relay forming the fifth and sixth outputs of the start-up control ~ -unit.
It is desira~le that said synchronizing control unit ~` should comprise a relay-repeater for a signalling and inter-- :
locking contact of the switch of the electric generator, a :-~
relay for actuating the rotor-speed selector to increase ; rotational speed of the rotor, a relay for actuating the rotor-speed selector to reduce rotational speed of the rotor, and a relay-repeater for the sensor responsive to position of the rotor-speed selector, a feed circuit for a coil of said relay-~- 30 repeater for a signalling and interlocking contact of the switch of the electric generator including series-connected . .

9~2~

contacts, namely, a make contact of the start-up completion relay and a make signalling and interlocking contact of the switch of the electric generator, a feed circuit of the relay for actuating the rotor-speed selector to increase rotational speed of the rotor being connected in parallel with both above contacts and including series-connected contacts, namely, a break contact of the relay-repeater for a signalling and interlocking contact of the electric-generator switch, a break contact of the relay for actuating the rotor-speed selector to reduce rotational speed of the rotor, and a break contact of the relay-repeater for the sensor responsive to position of the rotor-speed selector, a feed circuit for a coil of said relay for actuating the rotor-speed selector to reduce rotational speed of the rotor being connected in parallel with the two preceding contacts and incorporating series-connected contacts, namely, a make contact of the sensor responsive to rotational speed of the rotor, which contact is closed as the minimum speed at which the electric generator frequency still can be synchronized with the power supply frequency is exceeded, and a make contact of the relay-repeater for the sensor responsive to position of the rotor-speed selector, and, connected in parallel with the preceding contact, a make contact of said relay for actuating the rotor-., ~ speed selector to reduce rotational speed of the rotor, this .,;
contact making the second output of the synchronizing controlunit, a make contact of the relay for actuating the rotor-speed selector to increase rotational speed of the rotor .
forming the first output of the synchronizing control unit, and a make contact of the relay-repeater for a signalling and interlocking contact of the electric-generator switch forming .~ the third output of the synchronizing control unit, and a . X~

, . . , , :

feed circuit for a coil of said relay-repeater for the sensor responsive to position of the rotor-speed selector including a make contact of this sensor, which contact is closed as the rotor-speed selector is shifted to its extreme position to thereby increase rotational speed of the gas turbine rotor.
It is preferable that said load-increase control unit should comprise a load-increase relay, a feed circuit for a coil of this relay incorporating series-connected contacts, namely, a make contact of the relay-repeater for the signalling and interlocking contact of the electric-generator switch, a break contact of the sensor responsive to the furnace-gas flow rate, which contact is opened when the flow rate of fur- ;
nace gas passing through the gas turbine reaches its peak without operating the gas heater, and a break contact of the sensor responsive to position of the rotor-speed selector, which contact is opened as the selector is shifted to its extreme position to increase rotational speed of the rotor, make contacts of the load-increase relay forming the fi.rst . and second outputs of the load-increase control unit.
It is expedient that said gas-heating control unit should comprise a push-button switch for releasing the gas heater from protections, an auxiliary relay, a relay for con-.,:
~ trolling the flow rate of furnace gas, a relay for starting : the gas heater, a relay for actuating the ignitor, a time relayfor switching off the ignitor, a relay for switching off the ignitor, a relay for controlling temperature of gas at the `~ ignitor outlet, a relay for actuating the corresponding elec-tric drive to open the valve in the conduit for the delivery of air to the gas heater, a time relay for starting the gas heater, a relay operative upon completion of the gas heater starting, a relay for controlling the minimum flow rate of gas, ..~-. . . : .
: ::

a relay for changing over the-electric generator to motor operation, a relay for actuating the electric drive to close the valve in the conduit for the delivery of air to the gas :
heater, and a relay for shutting down the gas(heater, a feed circuit for a coil of said auxiliary relay including a make contact of the load-increase relay, a make contact of said auxiliary relay connected in parallel with the above contact, and a break contact forming the fifth output of the shut-down control unit, connected in series with the above contacts, a feed circuit for a coil of said relay for controlling the furnace-gas flow rate including a make contact of the sensor responsive to furnace-gas flow rate, which contact is closed as the rate of furnace-gas flow through the gas turbine reaches a value at which the gas heater is started up, a feed circuit for a coil of said relay for starting the gas heater including a make contact of the auxiliary relay, a make contact of the relay for controlling the furnace-gas flow rate and a make contact of the relay for permitting the gas-heater starting both contacts being connected in series, a make con-.
~: 20 tact of said relay for starting the gas heater connected in . parallel with the above contacts, a break contact of the relay operative upon completion of the gas-heater starting connected -.: in series with the preceding contacts, and a break contact of the relay for shutting down the gas heater connected in series ~` with all the preceding contacts~ two make contacts of the relay for starting the gas heater forming the first and second ~ outputs of the gas-heating control unit, a feed circuit for ; a coil of said relay for actuating the ignitor incorporating ` series-connected contacts, namely, a make contact of the relay for starting the gas heater and a ~reak contact of the relay for switching off the ignitor, a coil of the time relay for ~, ;;

2~

switching off the ignitor being connected in parallel with the coil of the relay for actuating the ignitor, a make contact of said time relay for switching off the ignitor forming the fourth output of the gas-heating control unit, a feed circuit ~-for a coil for switching off the ignitor incorporating a make contact of the time relay for switching off the ignitor and, connected in parallel with this contact, two series-connected contacts, namely, a make contact of said ignitor switching-off relay and a break contact of the relay for shutting down the ;
gas heater, a feed circuit for a coil of said relay for con-trolling gas temperature at the ignitor outlet incorporating a make contact of the sensor responsive to gas temperature at the ignitor outlet, which contact is opened as the temperature of gas exceeds the ignition point thereof, a feed circuit for a coil of said relay for actuating the corresponding electric drive to open the valve in the conduit for the delivery of air -~ to the gas heater incorporating series-connected contacts, i. namely, a make contact of the relay controlling gas temperature at the ignitor outlet, a make contact of the ignitor switching-. 20 off relay, and a break contact of said relay for changing over the electric generator to motor operation, a make contact of said valve-opening relay forming the third output of the gas-~: heating control unit, a feed circuit for a coil of said time relay for starting the gas heater incorporating series-connected contacts, namely, a make contact of the sensor res-ponsive to position of the valve in the conduit for the delivery of air to the gas heater, which contact is closed upon opening of that valve, and a break contact of the start-up completion relay, a feed circuit for a coil of said relay operative upon completion of the gas heater starting incorporating a make contact of the time relay for starting the gas heater, :
.

$~23 a make contact of said start-up completion relay connected in parallel with the preceding contact, and series-connected contacts, namely, a break contact of the relay for shutting down the gas heater, and a break contact of the generator-to-motor changeover relay, two break contacts of the start-up completion relay forming the fifth and eleventh outputs of the gas-heating control unit, a feed circuit for a coil of said relay for controlling the minimum furnace-gas flow rate incorporating a break contact of the sensor responsive to furnace-gas flow rate which contact is opened as th~ furnace-gas flow rate exceeds its minimum value at which the delivery of air to the gas heater is cut off, a feed circuit for a coil of said relay for changing over the electric generator to motor operation incorporating a make contact of the relay for controlling the minimum flow rate of blast-furnace gas~ a make contact of said generator-to-motor changeover relay and a break ,, .
.~ contact of the relay for controlling blast-furnace gas flow rate, both contacts being connected in parallel to the preceding contact, and a make contact of the auxiliary relay connected in series with all the three preceding contacts, a feed circuit , ... ~
for a coil of said relay for actuating the corresponding elec- ~:~
tric drive to close the valve in the conduit for the delivery of air to the gas heater incorporating two contacts connected in parallel, namely, a make contact of the generator-to-motor changeover relay and a make contact of the relay for shutting down the gas heater, a make contact of said valve-closing relay forming the eighth output of the gas-heating control unit, a feed circuit for a coil of said relay for shutting down the gas heater incorporating series-connected contacts, namely, a break contact of the relay controlling the tempera-ture of furnace gas at the outlet of the ignitor and a make ., : . . , ~q39~23 contact of the relay for switching off the ignitor, a make contact of the relay of the second sensor responsive to the blast-furnace gas temperature at the inlet of the gas turbine connected in parallel with the two abo~e contacts, which con- -tact is closed as the temperature of blast-furnace gas reaches its maximum value at which the gas heater is shut down, a break contact of the second sensor responsive to temperature of blast furnace gas, which is closed as the furnace gas temperature drops to its minimum value at which the gas heater is shut down and a make contact of the start-up completion relay, both contacts being connected in series with one another and in parallel with the preceding contacts, a make contact forming the seventh output of the shut-down control unit, -connected in parallel with the preceding contacts, a make con-tact forming the sixth output of the shut-down control unit and a make contact of the relay for controlling the minimum furnace-gas flow rate, both contacts connected in series to one another and in parallel with the preceding contacts, and a make contact of said relay for shutting down the gas heater, which is connected in parallel with the preceding conta-ts, a break contact of said push-button switch for releasing the gas heater from portections being connected in series with all the preceding contacts, three make contacts of the relay for shutting down the gas heater forming the sixth, seventh, and tenth outputs, and one break contact thereof making up the ninth output of the gas-heating control unit.
It is advantageous that said control unit for changing over the regulator of gas pressure under the blast-furnace top should comprise a relay for the regulator changeover and a relay for reducing load of the turbine, a feed circuit for a coil of said ~hangeover relay incorporating series-connected contacts, namely, a make contact of the sensor responsive to the blast-furnace gas temperature at the inlet of the gas turbine, which contact is closed as the temperature of furnace gas exceeds its minimal value at which the pressure regulator can be changed over to connection with the input of thes system for regulating rotational speed of the rotor, a break conta~t of the relay for shutting down the gas heater, and a break contact forming the eighth output of the shut-down con-trol unit, two make contacts of the changeover relay forming the first and second outputs of the changeover control unit, a feed circuit for a coil of said relay for reducing load of the turbine incorporating a make contact of the relay for shutt-ing down the gas heater, a break contact of the relay opera-tive upon completion of the gas heater starting, this second contact being connected in parallel with the preceding con-tact, and a make contact of the sensor responsive to the flow , . :
;. rate of furnace gas, which contact is closed as the rate of ~`. gas flow through the gas turbine reaches its maximum value ~ ,~
:~ without the gas heater being operative, this third contact ~;~ 20 being connected in series with the preceding, second contact, .
a break contact and a make contact of the relay for reducing ` load of the turbine forming the third and fourth outputs of . : the changeover control unit.
It is preferable that said shut-down control unit should comprise a push-button switch for stopping the in-stallation, a push-button switch for installation-protection release, a shut-down relay, a relay for disconnecting the electric generator from the power line, and an emergency shut-down relay, a feed circuit for a coil of said shut-down relay incorporating a make contact of said push-button switch for stopping the installation, two series-connected contacts which are connected in parallel with said push-button switch contact, '~c~

...

t namely, a make contact of the relay for preparing the start-ing of the oi~ pump and a make contact of this shut-down :
relay, and a make contact of the emergency shut-down relay connected in parallel with the preceding contact, break con-tacts of the shut-down relay forming the first, fifth, and .
: eighth outputs, and make contacts thereof forming the fourth, sixth and tenth outputs of the shut-down control -:.
~ unit, a feed circuit for a coil for disconnecting the elec-tric generator from the power line incorporating series-connected contacts, namely, a ma~e contact of the shut-down .~ relay and a make contact of the sensor responsive to position , , :
of the closing diaphragm gate which contact is closed upon closure thereof, make contacts of the relay for disconnecting the electric generator forming the second and ninth outputs of the shut-down control unit, a feed circuit for a coil for said emergency shut-down relay incorporating contacts conn-;` ected in parallel, namely, a make contact of the sensor ~;~ responsive to rotational speed of the rotor, which contact is closed as the rotor speed reaches its maximum value, a make contact of the sensor responsive to temperature of blast-furnace gas ahead of the gas turbine, a make contact of the sensor responsive to the maximum temperature of bearings of the gas turbine and the electric generator, a make contact of the sensor responsive to vibration of bearings of the gas turbine and the electric generator, and a make contact of this emergency shut-down relay, and also series-connected contacts, namely, a make contact of the sensor responsive to oil pressure in the oiling system, which contact is closed as the pressure of oil drops to its minimum permissible limit, and a break contact of the sensor responsive to position of the valve in the conduit for the delivery of blast-furnace . ~ :

L2~

gas to the installation, which contact is opened upon the opening of that valve, these two series-connected contacts being connected in parallel with all the above contacts, and a break contact of a push-button switch for reieasing the installation from protections being connected in series with all the preceding contacts of this feed circuit, make contacts of the emergency shut-down relay forming the third and seventh outputs of the shut-down control unit.
It is preferable that said control unit for filling 10 and emptying the installation should comprise a switch to actuate the filling and opening, a relay for actuating the electric drive of the valve in the conduit for the delivery of blast-furnace gas to the installation, a feed circuit for a coil of this relay in-corporating a make contact of the shut-down relay which forms the ;~
tenth output of the shut-down control unit, a make contact of said relay for actuating the electric drive of the valve in the conduit for the delivery of blast-furnace gas to the installation forming the second output of the filling and emptying control unit, a relay operative upon closure of the valve in the con-duit for the delivery of blast-furnace gas to the installation, a feed circuit for a coil of this relay incorporating a make contact of the sensor responsive to position of said valve, which contact is closed upon closure thereof, a relay opera-tive upon opening of the valve in the conduit for the dis-charge of blast-furnace gas, a feed circuit for a coil of this relay incorporating a make contact of the sensor res-ponsive to position of said valve, which contact is closed upon opening thereof, a relay operative upon closure of the valve in the conduit for the delivery of inert gas, a feed circuit for a coil of this relay incorporating a make contact of the sensor responsive to position of said valve, ~' ~ - 31 -, . ., ::

2~3 which contact is closed upon closure thereof, a relay ~or actuating the corresponding electric drive to close the valve in the conduit for the discharge of blast-furnace gas, -a feed circuit for a coil of this valve incorporating series-"
connected contacts, namely, a make contact of the relayoperative upon closure of the valve in the conduit for the delivery of blast-furnace gas to the installation, and a make contact of said switch for actuating the filling and emptying, which contact is closed in the "emptying" position of the switch, a relay for acutating the corresponding electric drive to open the valve in the conduit for the dis-charge of the contaminated inert gas, whose coil and a make contact of the sensor responsive to position of the valve in the conduit for the discharge of blast-furnace gas from the installation, which contact is closed upon closure of said valve, are connected in series with the above contact of said switch, a relay for actuating the corresponding electric drive to open the valve in the conduit for the delivery of inert gas, whose coil and a make contact of the sensor res-ponsive to position of the valve in the conduit for the dis-charge of the contaminated inert gas from the installation, which contact is closed upon closure of that valve, are conn-ected in series to one another and in parallel with the pre-ceding contact and relay coil, a make contact of said relay for actuating the electric drive to close the valve in the conduit for the discharg~ of blast-furnace gas forming the third output, a make conta^t of the relay for actuating the electric drive to open the valve in the conduit for the discharge of the contaminated inert gas forming the eighth output, and a make contact of the relay for actuating the electric drive to open the valve in the conduit for the . , - : . - ,:, . ~.. . .

~$~23 delivery of inert gas forming the seventh output of the fill-ing and emptying control unit, a time relay for emptying the installation, a feed circuit for a coil of this time relay incorporating a make contact of the sensor responsive to position of the valve in the conduit for the delivery of inert gas to the installation, which contact is closed upon :
. opening of said valve, a relay for actuating the respective electric drives to close the associated valves in the conduit for the delivery of inert gas and in the conduit for the dis-charge of the contaminated inert gas, a feed circuit of this relay incorporating series connectec contacts, namely, a make contact of the filling and emptying control switch, . which contact is closed in the neutral position of the switch, .~ and a make contact of the time relay for emptying the in-:.~ stallation, and, connected in parallel with the latter contact, a make contact of the relay operative upon closure of the valve in the conduit for the discharge of blast-furnace gas, make contacts of the relay for actuating the respective electric drives to close the associated valves in the conduit for the delivery o~ inert gas and in the conduit for the discharge of the contaminated inert gas forming the fourth and fifth outputs of the filling and emptying control unit, a relay for actuating the corresponding electric drive to open the valve in the conduit for the discharge of the blast-furnace gas, a feed circuit for a coil of this relay incorporating series-connected contacts, namely, a make contact of the relay operative on closure of the valve in the conduit for the delivery of inert gas and a make contact of the filling and opening control switch, which contact is closed in the "fill-ing" position of the switch, a make contact of the relayoperative upon the opening of the valve in the conduit for ~ !
~ - 33 -~9~23 the discharge of blast-furnace gas and the coil of the relay for actuating the electric drive of the valve in the conduit for the discharge of the contaminated inert gas being connected in series with the preceding contact of the filling and emptying control switch, a make contact of the relay for actuat-~: ing the corresponding electric drive to open the valve in the :
conduit for the discharge of blast-furnace gas forming the sixth output of the filling and emptying control unit, and an -.~ output relay, a feed circuit for a coil of this relay incor-.: 10 porating series-connected contacts, namely, a make contact of -~ the relay operative upon closure of the valve in the conduit for the delivery of the blast furnace gas, a make contact of the relay operative upon the opening of the valve in the con-duit for the discharge of blast-furnace gas, a make contact of the relay operative upon closure of the valve in the conduit for the delivery of inert gas, and a make contact of the sensor responsive to position of the valve in the conduit for the discharge of the contaminated inert gas, which contact is closed upon closure of that valve, a make contact of said output relay forming the first output of the filling and empt~ing control unit.
The present invention makes it possible to effec- :
tively solve complex and variable problems stemming from the development of a fully automatic control system for an in-stallation utilizing the pressure energy of outgoing blast-furnace gas. Fully automatic control is accomplished by the provision of a control system comprising the following func-tionally-oriented control units, namely: a control unit for checking the installation for start-up readiness, a control unit for starting the installation, a control unit for syn-chronizing the electric generator frequency and the power line frequency, a control unit for increasing load of the gas ~,.~

2~

turbine, a control unit for monitoring the heating of blast-furnace gas, a control unit for changing over the furnace-gas pressure regulator, a control unit for shutting down the in-stallation, and a control unit for filling and emptying the installation. The inputs and outputs of these units and of suitable sensors and operative members are interconnected so as to ensure appropriate operation thereof.
The use of the aforesaid units in a control system ~` allows all necessary control operations to be carried out automatically, and connections-between the control units, sensors and operative members in accordance with the present invention ensure the required sequence of operations, with each preceding operation being checked up for its proper completion.
The splitting of the control system as a whole into said series-connected functional units with additional conn-ections therebetween makes it possible to facilitate their manufacture, to use therefor conventional electromagnetic relays, to reduce the number of such relays to an optimal value, to use the same units to thereby control the install-ation functioning under changing operational conditions, and hence to simplify the whole control system.
The control system thus simplified and its arrange-ment according to the invention facilitates the setting thereof, allowing the setting and adjustment of separate units to be made simultaneously, and thereby the time required for putting the system into operation to be substantially reduced.
In operation, the system offers effective detection of faults, simpler troubleshooting, servicing and maintenance.
The checking of operations upon their completion excludes the upsetting of their specified sequence.

L~

That makes for higher reliability of the installation - and prevents damage to equipment and hazards to the personnel running the blast furnace.
A fully automatic control system according to the invention makes it possible to use a gas-pressure utilizing -~ installation without creating any difficulties for operation of a blast-furnace to which it is coupled.
The present invention will now be described in terms of a specific embodiment thereof with reference to the accom-panying drawings. In the drawings:
Fig. 1 diagrammatically illustrates a general sch-ematic arrangement of an installation utilizing the pressure energy of outgoing blast-furnace gas, according to the invention' Fig. 2 is a schematic diagram in block form of a control system for the installation of Fig. 1, according to the invention, Fig. 3 is a schematic circuit diagram of a readiness control unit, according to the invention, Fig. 4 is a schematic circuit diagram of a start-up control unit, according to the invention;
Fig. 5 is a schematic circuit diagram of a frequency synchronizing control unit, according to the invention' Fig. 6 is a schematic circuit diagram of a load-increase control unit, according to the invention' Fig. 7 is a schematic circuit diagram of a gas-heating control unit, according to the invention Fig. 8 is a schematic circuit diagram of a pressure-regulator changeover control unit, according to the invention' Fig. 9 is a schematic circuit diagram of a shut-down control unit, according to the invention, .; .

z~ ~
:

Fig. 10 is a schematic circuit diagram of a filling and emptying control unit, according to the invention.
Referring now to Fig. 1 of the drawings, a control system for an installation utilizing the pressure energy of ~- outgoing blast-furnace gas, according to the invention, ", .
includes mounted in a gas turbine l,-a control diaphragm gate 2 and a closing diaphragm gate 3. The gas turbine 1 is placed in parallel with a throttle unlt 4 of a blast-furnace 5 and ~;
is used to impart rotation to an electric generator 6. The electric generator is provided with a suitable air cooling system incorporating a power-driven ventilator 7. The gas turbine 1 is provided with an oiling system incorporating an oil pump 8, said oiling system being also shared by the elec-tric generator 6, with a system 9 for regulating rotational speed of the rotor of said turbine 1 and with a rotor-speed selector 10. The regulating system 9 is connected to said control diaphragm gate 2 and closing diaphragm ~ate 3.
The control system has a device 11 for converting input signals coming from a regulator 12 of gas pressure under the top of the blast furnace 5. The converting device 11 is connected to the input of said regulating system 9. The pressure regulator 12 is electrically connected with the throttle unit 4. There are also provided a switch 13 of the electric generator 6, which contains a set of signalling and inter-locking contacts and is used to connect and disconnect the electric generator from a power line, and a device 14 used to synchronize the rotor rotational frequency and the p~wer-line frequency. A first and second inputs 15 and 16 of said device 14 are connected respectively with outputs of the electric generator 6 and with an a.c. power line, and a first output 17 thereof is electrically connected to said switch 13 of the electric generator 6.

~, .. ~ ,: ............. . .... :

i The control system alsc contains a first sensor 18 responsive to the blast-furnace gas temperature at the inlet of the gas turbine 1, which sensor is mounted in a conduit 19 for the delivery of blast furnace gas to the gas turbine 1 downstream of a gas heater 20 which is also mounted therein and provided with an ignitor 21. Said sensor 18 is connected to an input 22 of a regulator 23 used to control temperature of the blast-furnace gas passing to the gas turbine 1. An output of said temperature regulator 23 is electrically connected to an electric drive 25 for operating a valve 24 coupled therewith and mounted in a conduit 26 for the delivery ~ of air to the gas heater 20. A second sensor 27 responsive : to the maximum gas temperature is also mounted in said con-duit 19. A gas filter 28 is mounted on the downstream side of the blast furnace 5.
The control system further includes a valve 29 with its associated electric drive 30 mounted in a conduit 31 for the delivery of blast-furnace gas to the installation ahead of the gas heater 20, a valve 32 with its electric drive 33, mounted in the conduit 34 for the discharge of contaminated ; inert gas from the installation, a valve 35 with its electric drive 36, placed in a conduit 37 for the discharge of blast-furance gas from the installation, a valve 38 with its electric drive 39 mounted in a conduit 40 for the delivery of inert gas to the installation, a valve 41 with its electric drive 42, mounted in the conduit 26 for the delivery of air to the gas heater 20, a valve 43 with its electric drive 44, mounted in a conduit 45 for the delivery of air to the ignitor 21 of -the gas heater 20, and a valve 46 with its electric drive 47, : 30 mounted in a conduit 48 for the delivery of gaseous fuel to the ignitor 21 of the gas heater 20.

; ~ - 38 -; ~ . ,- . . . ... .

2;3 -A number of interconnected control units for theautomatic starting, control and shut-down of the installation is introduced in the control system.
Referring to Fig. 2, there is provided a control ^ unit 49 for checking the installation for start-up readiness.
A first input 50 of said readiness control unit is connected with a sensor 51 responsive to position of said valve 41, shown in Fig. 1, which produces a signal indicative of the valve closure. A second input 52 of the control unit 49 is connected with a sensor 53 responsive to position of said valve 43 (Fig. 1), said sensor being placed in the conduit 45 for the delivery of air to the ignitor 21 of the gas heater 20, which produces a signal indicative of closure of this valve. A third output 54 of the control unit 49 is connected with a sensor 55 responsive to position of said valve 46 (Fig. 1), producing a signal indicative of the valve closure. A fourth input 56 o~ the control unit 49 is connec-ted with a sensor 57 responsive to air pressure in the conduit 26 ahead of the valve 41 (Fig. 1), which produces a signal 2~ indicative of the air pressure being within its operative limits. A fifth input 58 of the control unit 49 is connected with a sensor 59 responsive to air pressure in the conduit , 45 ahead of the valve 43 (Fig. 1), which produces a signal indicative of the air pressure being within its operative limits. A sixth input 60 of the control unit 49 is connected with a sensor 61 responsive to the pressure of a high-grade gaseous fuel in the conduit 48 ahead of the valve 46 (Fig.l), which produces a signal indicative of the gaseous-fuel press-ure being within its operative limits. A seventh input 62 of the control unit 49 is connected with a sensor 63 res-ponsive to oil level in the oiling system of the gas turbine 1, ~$~X;~

producing a signal indicative of the oil level being within its operative limits. An eighth input 64 of the control unit 49 is connected with a sensor 65 responsive to position of the closing diaphragm gate 3 (Fig. 1), producing a signal indicative of its closure, and a ninth input 66 of the control unit 49 is connected with a sensor 65 responsive to position of the closing diaphragm gate 3 (Fig. 1), producing a signal indicative of its closure, and a ninth input 66 of the control unit 49 is connected with a sensor 67 responsive to position of the control diaphragm gate 2 (Fig. 1), producing a signal indicative of its closure. A tenth input 68 of the control unit 49 is connected with a sensor 69 responsive to position of the rotor-speed selector 10 (Fig. 1), producing a signal indicative of the selector initial position. An eleventh input 70 of the control unit 49 is connected with a sensor 71 responsive to position of the signal-converting device ll(Fig. 1), producing a signal indicative of the initial position of the device 11.
The control system also includes a start-up control unit 72 (Fig. 2) which is adapted for starting the oil pump 8 (Fig. 1)~ opening the valve 29, starting the ventilator 7, actuating the rotor-speed selector 10 and stopping the oil pump 8 and the rotor-speed selector 10 as the rotor rotational frequency reaches a value which is roughly equal to the gener-ator synchronizing frequency, all these operations being carried out in the aforesaid succession. A first input 73 of the start-up control unit 72 is connected with a first output 74 of the readiness control unit 49. A second input 75 of the start-up control unit 72 is connected with a sensor 76 responsive to oil pressure in the oiling sy~-tem of the gas turbine 1 (Fig. 1), which sensor produces a signal indicative ~c~
~ - 40 -~1$~!~2;3 of the oil pressure being within its operative limits, A
third and fourth inputs 77 and 78 are connected respectively with sensors 79 and 80 responsive to position of the valve 29 (Fig. l), which produce respective signals indicative of its being opened and closed. A fifth input 81 of the start-up control unit 72 is connected with a sensor 82 responsive to air pressure in the cooling system of the electric generator 6 (Fig, 1), which sensor produces a signal indicative of the ! ;
air pressure being within its operative limits. A sixth input 83 of the start-up control unit 72 is connected with a sensor 84 responsive to rotational speed of the turbine rotor, which produces a signal as the rotor rotational frequency reaches a ; value roughly equal to the synchronizing frequency of the electric generator 6 (Fig, l), A first, second, third and fourth outputs 85, 86, 87 and 88 of the start-up control unit 72 are electrically connected respectively to the oil pump 8, to the electric drive 30 of the valve 29 (Fig. l), to the power-driven ventilator 7, and to the rotor-speed selector lO. A fifth output 89 of the control unit 72 is electrically connected to a third input 90 of the synchron-izing device 14.
The control system further includes a control unit 91 (Fig. 2) for synchronizing the electric-generator frequency ~; and the power-line frequency. A first input 92 of this control unit is connected to a sixth output 93 of the control unit 72, a second input 94 thereof being connected to a first signalling and interlocking make contact 95 of the switch 13 (Fig. l) of the electric generator 6, which produces a signal indicative of the electric generator 6 being connected to the power line. A third input 96 of the control unit 91 is `~

.,.. ., :, .

~ 3~

connected with a sensor 97 responsive to position of the rotor-speed selector 10 (Fig. 1), which produces a signal indicative of the selector being shifted to its extreme position to thereby increase the rotor speed. A fourth input 98 of the control unit 91 is connected with a sensor 99 responsive to rotational speed of the rotor, producing a signal as the rotor speed drops to its minimal value at which the electric-generator frequency can still be synchronized with the power-line fre-quency. A first and second outputs 100 and 101 of the control unit 91 are connected to the rotor-speed selector 10 to in-crease and reduce rotational speed of the rotor of the gas turbine 1 (Fig. 1), respectively.
The control system also includes a control unit 102 (Fig. 2) for increasing load of the gas turbine. A first in-put 103 of this load-increase control unit is connected to a third output 104 of said control unit 91. A second input 105 of the control unit 102 is connected with a sensor 106 res-ponsive to furnace-gas flow rate, which produces a signal as ` the rate of gas flow through the gas turbine l(Fig. 1) reaches its maximum value without operating the gas heater 20. A
third input 107 of the control unit 102 is connected with said sensor 97 responsive to position of the rotor-speed selector 10. A first output 108 of the control unit 102 is connected to said selector 10.
The control system further includes a control unit 109 (Fig. 2) for controlling the heating of blast furnace gas, which is used to start up and stop the gas heater 20 (Fig. 1) and the temperature regulator 23 thereof, and also to carry out control operations required during a temporary changeover of the blast-furnace to operation with reduced furnace-gas pressure. A first output 110 of this gas-heating control unit - : ~- ,, . : , : : :

2~

109 is connected with a second output 111 of said load-increase control unit 102, and a second input 112 of the control unit 109 is connected with a second output 113 of said read-iness control unit 49. A third input 114 of the control unit 109 is connected with a sensor 115 responsive to the rate of gas flow through the turbine 1 (Fig. 1), producing a signal as the flow rate reaches its value at which the gas heater 20 is started up. A fourth input 116 of the control unit 109 is connected with a sensor 117 responsive to gas temperature at the outlet of the ignitor 21 (Fig. 1), which produces a signal indicative of the temperature exceeding the furnace-gas ignition point. A fifth input 118 of the control unit 109 is connected with a sensor 119 responsive to position of the valve 41 (Fig. 1), which produces a signal indicative of this valve being opened. A sixth input 120 of the control unit 109 is connected to a sensor 121 responsive to furnace-gas flow rate, producing a signal as the rate of gas flow through the gas turbine 1 (Fig. 1) reaches its value at which the delivery of air to the gas heater 20 is shut o~f. A
seventh and an eighth inputs 122 and 123 of the control unit 109 are connected, respectively, with the outputs of said second sensor 27 responsive to the furnace-gas temperature at the inlet of the gas turbine 1 (Fig. 1), producing res-pective signals as the gas temperature reaches its minimum and maximum values at which the gas heater 20 is shut down.
A first, second, and third outputs 124, 125 and 126 of the control unit 109 are electrically connected to the respective electric drives 44, 47 and 42 of the associated valves 43, 46, and 41 (Fig. 1) for their opening. A fourth output 127 of the control unit 109 is electrically connected to the ig-nitor 21, and a fifth output 128 of the control unit 109 . : - ~: .

3$~iLZ3 thereof is electrically connected to the furnace-gas tempera-ture regulator 23 to switch it "on" and "off". A sixth, a seventh and an eighth outputs 129, 130, and 131 of the con-trol unit 109 are electrically connected to the respective electric drives 44, 47 and 42 of the associated valves 43, 46 and 41 for their closure.
The control system also includes a changeover , control unit 132 (Fig. 2) used to connect the regulator 12 of gas pressure under the top of the blast-furnace 5 either 10 through the input-signal converter 11 to an input of the rotor-speed regulation system 9 or to an input of the throttle unit 4 of the blast-furnace 5. A first, a second, and a third inputs 133, 134 and 135 of this unit 132 are connected respectively with a ninth, a tenth, and an eleventh outputs 136, 137, 138 of said gas-heating control unit 109. A fourth input 139 of the control unit 132 is connected with said sensor 106 (Fig. 1). A fifth input 140 of the control unit 132 is connected with a sensor 141 responsive to gas tempera-ture at the inlet of the gas turbine 1, producing a signal 20 indicative of the minimum temperature of gas in the turbine at which the pressure regulator 12 is connected to the input of the rotor-speed regulating system 9. A first output 142 of the control unit 132 is electrically connected to the rotor-speed selector 10. A second output 143 of the control unit 132 is electrically connected with the output of the pressure regulator 12 to connect and disconnect said pressure regula-tor 12 through the input-signal converter 11 to the input of the rotor-speed regulating system 9 (Fig. 1). A third output 144 is electrically connected with the output of the pressure 30 regulator 12 to connect and disconnect the pressure regulator 12 to and from the input of the throttle unit 4 (Fig. 1). A

fourth output 145 is electrically connected through the ~r -- 44 --, ~

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input-signal converting device 11 to a corresponding input of the system 9 (Fig 1) for transmitting a signal to reduce load of the gas turbine 1.
The control system further includes a shut-down control unit 146 (Fig. 2) used to stop the installation. A
first input 147 of this unit is connected with a seventh output 148 of the start-up control unit 72, and a second input 149 thereof is connected with said sensor 65. A third input 150 of the control unit 1~6 is connected with a sensor 151 responsive to rotational speed of the rotor, producing a signal indicative of the maximum rotor speed. A fourth input 152 of the control unit 146 is connected with a sensor 153 responsive to oil pressure in the oiling system, producing a signal as the oil pressure drops to its minimum value. A
flfth input 154 of the control unit 146 is connected to a sensor 155 responsive to position of the valve 29 (Fig. 1), producing a signal indicative of the beginning of said valve opening. A sixth input 156 (Fig. 2) of the control unit 146 is connected with said second sensor 27 lFig. 1), and a seventh input 157 (Fig. 2) thereof is connected with a sensor 158 responsive to the maximum temperature of hearings of the gas turbine 1 (Fig. 1) and the electric generator 6. An eighth input 159 (Fig. 2) of the control unit 146 is connected to a sensor 160 responsive to vibration of bearings of the gas turbine 1 and the electric generator 6 (Fig. 1), producing a signal indicative of the maximum vibration of the bearings.
A first and second outputs 161 and 162 (Fig. 2) of the control unit 146 are connected respectively to a seventh and an eighth inputs 163 and 164 of the start-up control unit 72.
A third output 165 of the control unit 146 is electrically i connected to a corresponding input of the rotor-speed regula-ting system 9 for rapid closu;^e of the control and closing 2~

diaphragm gates 2 and 3. A fourth output 166 (Fig. 2) of the control unit 146 is electrically connected to the rotor-speed selector 10 to transmit a signal for bringing the selector 10 back to its initial position. A fifth, sixth, and seventh t outputs 167, 168, and 169 of the control unit 146 are connec-ted, respectively, to a ninth, tenth, and eleventh inputs 170, 171, and 172 of the gas-heating control unit 109. An eighth output 173 of the control unit 146 is connected to a sixth input 174 of the changeover control unit 132, a ninth output 175 (Fig. 2) of the control unit 146 is electrically connected with the switch 13 (Fig. 1).
The control system also i~cludes a control unit 176 (Fig. 2) for filling and emptying the installation. A ~irst `~
input 177 of this unit is connected to a tenth output 178 of the shut-down control unit 146, and a second input 179 of the control unit 176 is connected with said sensor 80. A third and fourth inputs 180 and 181 (Fig. 2) of the control unit 176 axe connected with the respective sensors 182 and 183 responsive to position of the valve 35 (Fig. 1), which pro-duce respective signals indicative of this valve being closed and opened. A fifth and sixth inputs 184 and 185 (Fig. 2) of the control unit 176 are connected to respective sensors 186 and 187 responsive to position of the valve 38 (Fig. 1), which produce respective signals indicative of this valve being closed and opened. A seventh and an eighth inputs 188 and 189 (Fig. 2) of the control unit 176 are connected with respective sensors 190 and 191 responsive to position of the valve 32 (Fig. 1), which produce respective signals indica-tive of this valve being closed and opened. A first output 30 192 of the control unit 176 is connected to a twelfth input 193 of the readiness control unit 49. A second, third, fourth, and fifth outputs 194, 195, 196, and 197 of the ~` - 46 -,' X
- ~ .:, - . . . ~- .

- , . ~, r,: '' $~2~

control unit 176 are electrically connected respectively to the electric drive 30 of the valve 29 (Fig. 1), to the electric drive 36 of the valve 35, to the electric drive 39 of the valve 38, and to the electric drive 33 of the valve 32 to close all these valves. A sixth, a seventh, and an eighth outputs 198, 199, and 200 of the control unit 176 are electrically connected, respectively, to the electric drive 36 of the valve 35 (Fig. 1), to the electric drive 39 of the valve 38, and to the electric drive 33 of the valve 32 to open these valves.
For the purposes described hereinbefore, pressure-gauge switches can be used as suitable pressure-responsive sensors, thermocouples provided with electronic amplifiers having discrete electrical output can be used as suitable temperature-responsive sensors, pressure switches with elas-ticity-calibrated membranes responsive to a pressure drop which are mounted on the conduits can be used as suitable flow-rate sensors, limit switches with electrical output can be used as suitable position-responsive sensors for the closing and control diaphragm gates, the valves, the rotor-speed selector, and the input-signal converting device, a float-type level relay with electrical output signal can be used as a suitable level-responsive sensor, and inductive vibration pick-ups can be used as suitable vibration-responsive sensors.
Reference is now made to Fig. 3, illustrating a schematic circuit diagram of said control unit 49 for checking the installation for start-up readiness. This control unit has a relay for permitting the starting of the gas heater 20 (Fig. 1). This relay has a coil 201 whose -~ feed circuit incorporates series-connected contacts, namely, a make contact 511 of the sensor 51 (Fig. 2) responsive to ' ' ' ~

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position of the valve 41 tFig. 1), which contact is closed upon closure of this valve, a make contact 531 of the sensor 53 (Fig. 2) responsive to position of the valve 43 (Fig. 1), which contact is closed upon closure of this valve, a make 551 contact of the sensor 55 (Fig. 2) responsive to position of the valve 46 (Fig. 1) which contact is closed upon closure of this valve, a make contact 571 of the sensor 57 (Fig. 2) responsive to air pressure ahead of the valve 41, which con-tact is closed while the air pressure is within its operative limits, a make contact 591 of the sensor 59 (Fig. 2) respon-sive to air pressure ahead of the valve 43 (Fig. 1), which contact is closed while the air pressure is within its opera-tive limits, and a make contact 611 of the sensor 61 (Fig. 2) responsive to gaseous-fuel pressure ahead of the valve 46 (Fig. 1), which contact is closed while the gaseous-fuel pressure is within its operative limits. A make contact (not shown in Fig. 3) of said relay for permitting the starting of the gas heater 20 (Fig. 1) makes up the second output 113 (Fig. 2) of the readiness control unit 49.
This control unit 49 also contains a relay for permitting the start-up of the installation. The relay has a coil 202, whose feed circuit incorporates series-connected contacts, namely, a make contact 631 of the sensor 63 (Fig. 2) responsive to oil level in the oiling system, which contact is closed while the oil level is within its specified limits, a make contact 651 of the sensor 65 (Fig. 2) responsive to position of the closing diaphragm gate 3 (Fig. 1), which con-tact is closed upon closure of this gate, a make contact 67 of the sensor 67 (Fig. 2) responsive to position of the ~; 30 control diaphragm gate 2 (Fig. 1), which contact is closed ' upon its closure, a make contact 691 of the sensor 69 (Fig. 2) responsive to position of the rotor-speed selector 10 (Fig. 1), ~r, i -~, ~ - 48 -: ' ,: . , .... ; ~.-~ - :

2;3 which contact is closed as the selector is in its initial position, a make contact 711 of the sensor 71 (Fig. 2) responsive to position of the input-signal converting device 11 (Fig. 1), which contact is closed as this device is in its -initial position, and a make contact 2011 of said relay for permitting the starting of the gas heater 20 (Fig. 1). A
make contact (not shown in Fig. 3) of said relay for permit-ting the start-up of the installation makes up the irst output 74 of the readiness control unit 49.
Conductors 203 and 204 form the supply bus bars for the control unit 49 and for all the other control units of the present control system.
Referring to Fig. 4, said start-up control unit 72, shown in Fig. 2, comprises a push-button switch "start" 205, an automatic-start relay having a coil 206, a relay with a coil 207 for preparing the starting of the oil pump 8 (Fig.
1), a time relay with a coil 208 for stopping the oil pump 8, a relay with a coil 209 for controlling the oil pump 8 (Fig.
1), a relay with a coil 210 for actuating the electric drive 30 to open the valve 29 (Fig. 1), a relay with a coil 211 for actuating the power-driven ventilator 7 (Fig. 1), a relay with a coil 212 for actuating the rotor-speed selector 10 (Fig. 1) and a relay with a coil 213 operative upon comple-tion of the starting of the installation.
A feed circuit for the coil 206 of said automatic-start relay incorporates a make contact of said push-button switch "start" 205 and a make contact 2021 of the relay for permitting the start-up of the installation. The make con-tact 2021 forms the first output 74 of the control unit 49 tFig. 2).
A make contact 2061 of said automatic-start relay is connected in parallel with said contacts 205 and 2021, and - . ~ -, :

a break contact 2131 of the relay operative upon completion of the installation start-up is connected in series with the con-tacts 205, 2021 and 2061.
A feed circuit for the coil 207 of said relay for preparing the startin~ of the oil pump 8 (Fig. 1) incorporates a make contact 2062 of the automatic-start relay, a make con-tact 2071 of this relay for preparing the oil pump starting connected in parallel with the contact 2062, and a break con-tact 2081 of the time relay for stopping the oil pump 8 con-nected in series with the contact 2062 and 2071. A corres- -ponding make contact (not shown in Fig. 4) of the relay opera-tive for preparing the oil pump 8 for starting forms the seventh output 148 (Fig. 2) of the start-up control unit 72.
A feed circuit for the coil 208 of said time relay for stopping the oil pump 8 incorporates a make contact 80 of the sensor 80 responsive to position of the valve 29 (Fig. 1), which contact is closed upon closure of this valve, and a make contact 2391 connected in series with the contact 801 .
A feed circuit for the coil 209 of said relay for controlling the oil pump 8 incorporates a make contact 2072 of the relay for preparing the oil pump starting, and a break contact 841 of the sensor 84 responsive to rotational speed :
~- of the rotor, which contact is opened as the rotor rotational frequency reaches the value roughly equal to the synchronizing frequency of the generator 6, the contacts 2072 and 841 being ~ connected in series. A make contact of the relay unit for `~ controLling the oil pump 8 is the first output 85 of the start-up unit 72.
` 30 A feed circuit for the coil 210 of the relay for ~;~ actuating the electric drive 30 to open the valve 29 incor-porates a make contact 761 of the sensor 76 (Fig. 2) responsive - ~

to oil pressure in the oiling system of the gas turbine 1, which contact is closed while the oil pressure is within its operative limits, and a make contact 2063 of the automatic-start relay, both contacts 761 and 2063 being connected in series.
A corresponding make contact (not shown in Fig. 4) of the relay for actuating the electric drive 30 to open the valve 29 forms the second output 86 (Fig. 2) of the start-up control unit 72.
A feed circuit 211 of said relay for actuating the ventilator 7 (Fig. 1) incorporates a make contact 791 of the ;;~
sensor 79 (Fig. 2) responsive to position of the valve 29 -~
(Fig. 1), which contact is closed upon the opening of said valve, a make contact (not shown in Fig. 4) of this relay for actuating the ventilator 7 forms the third output 87 of the ~ -start-up control unit 72. A coil 212 of the relay for actu-ating the rotor-speed selector 10 (Fig. 1), a make contact 82 of the sensor 82 (Fig. 2) responsive to air pressure in the cooling system of the electric generator 6, which contact is closed as the air pressure is within its operative limits, and a break contact 2132 of the relay operative upon completion of the turbine starting are connected in series with each other :-and in parallel with the coil 211. A corresponding make con-~;~ tact (not shown in Fig. 4) of the relay for actuating the ,, .:~
`~; rotor-speed selector 10 forms the fourth output 88 of the ~ start-up control unit 72.
- A feed circuit for the coil 213 of said relay opera-- tive upon completion of the installation starting incorporates ~ a break contact 2091 of the relay for controlling the oil ; 30 pump 8, a make contact 2121 for actuating the rotor-speed selector 10, connected in series with the contact 2091, and a make contact 2133 of this starting-completion relay, connected ,, in parallel with the contacts 2091 and 2122.
Make contacts (not shown in Fig. 4) of the starting-completion relay form the fifth and sixth outputs 89 and 93 of the start-up control unit 72.
Reference is now made to Fig. 5, illustrating a schematic circuit diagram of said synchronizing control unit 91, which comprises a relay-repeater with a coil 214 for a signalling and interlocking contact 95 (Fig. 2) of the switch 13 (Fig. 1), a relay with a coil 215 for actuating the rotor-speed selector 10 to increase rotational speed of the rotor, a relay with a coil 216 for actuating said rotor-speed selec-tor to reduce rotational speed of the rotor, and a relay-repeater with a coil 217 for the sensor 97 (Fig. 2) responsive to position of the rotor-speed selector 10.
A feed circuit for the coil 214 of the relay-repeater for the signalling and interlocking contact 95 of the switch 13 incorporates a make contact 2134 of the starting-completion relay and a make signalling and interlocking con-tact 95 of the switch 13.
Connected in series with said contact 2134, there is a feed circuit for the coil 215 of the relay for actuating the . l .
rotor-speed selector 10 to increase rotational speed of the rotor incorporating a make contact 2141 of said relay-repeater for the contact 95, a break contact 2161 of the relay for actuating the rotor-speed selector 10 to reduce the rotor-speed, and a break contact 2171 of the relay-repeater for the sensor 97 A feed circuit for the coil 216 of said relay for actuating the rotor-speed selector 10 to reduce rotational speed of the rotor is connected in series with said c~ntacts 2134 and 2141 and incorporates a make contact 991 of the ;, sensor 99 (Fig. 2) responsive to rotational speed of the ~ - 52 -2~

rotor, which contact is closed at the minimum speed thereof at which the frequency of the generator 6 (Fig. 1) and that of the power line still can be synchronized, and a make con-tact 2172 of the relay-repeater for the sensor 97, the con-tacts 991 and 2172 being connected in series.
A make contact 2162 of sald relay for actuating the rotor-speed selector 10 to reduce rotational speed of the rotor is connected in parallel with said make contact 2172 .
A make contact (not shown in Fig. 5) of the relay ; for actuating the rotor-speed selector 10 to increase the rotor speed forms the first output 100 (Fig. 2), a make con-tact (not shown in Fig. 5) of the relay for actuating the rotor-speed selector to reduce the rotor speed forms the second output 101 (Fig. 2), and a make contact (also not shown in Fig. 5) of the relay-repeater for the signalling and interlocking contact 95 of the switch 13 forms the third out-put 104 (Fig. 2) of the synchronizing control unit 91.
A feed circuit for the coil 217 of said relay-repeater for the sensor 97 incorporates a make contact 971 of this sensor, which is closed as the rotor-speed selector 10 is shifted to its extreme position for increased rota-tional speed of the rotor of the gas turbine 1.
Referring now to Fig. 6, said load-increase control unit 102, shown in Fig. 2, comprises a relay for increasing the installation load.
This relay has a coil 218 whose feed circuit incor-porates a make contact 2142 of the relay-repeater for the contact 95 (Fig. 2) of the switch 13 (Fig. 1), a break contact 1061 of the sensor 106 (Fig. 2) responsive to furnace-gas flow rate, which contact is opened as the rate of gas flow through the gas turbine 1 (Fig. 1) reaches its maximum ~ .
~.f~ O - 53 -value with the gas heater 20 being inoperative, and a break contact 972 of the sensor 97 (Fig. 2) responsive to position .
of the rotor-speed selector 10 (Fig. 1), which contact is opened as the selector is shifted to its extreme position for increased load, all these contacts being connected in series.
Make contacts (not shown in Fig. 6) of said load-increase relay form the first and second outputs 108 and 111 (Fig. 2) i of the load-increase control unit 102.
Reference is now made to Fig. 7 illustrating a schematic circuit diagram of said gas-heating control unit 109, which comprises a push-button switch 219 for releasing the gas heater 20 (Fig. 1) from its protections, an auxiliary relay with a coil 220, a relay with a coil 221 for controlling the furnace-gas flow rate, a relay with a coil 222 for start-ing the gas heater 20, a relay with a coil 223 for actuating the ignitor 21 (Fig. 1), a time relay with a coil 224 for switching off the ignitor 21, a relay with a coil 225 for switching off the ignitor 21, a relay with a coil 226 for controlling the gas temperature at the outlet of the ignitor ' ` 20 21, a relay with a coil 227 for actuating the electric drive ~`......................................................................... .
~ 42 to open the valve 41 (Fig. 1), a time relay with a coil .~
~ 228 for starting the gas heater 20, a relay with a coil 229 ~.
operative upon completion of the gas-heater starting, a relay with a coil 230 for controlling the minimum flow rate of gas, ~` a relay with a coil 231 for changing over the electric ~;' " `
generator to motor operation, a relay with a coil 232 for ` actuating the electric drive 42 to close the valve 41, and a relay with a coil 233 for shutting down the gas heater 20.
A feed circuit for the coil 220 of said auxiliary relay incorporates a make contact 2181 of the load-increase relay, a make contact 2201 of this auxiliary relay connected in parallel with the contact 2181, and a break contact 2383 forming the fifth output 167 of the shut-down control unit 146.
A feed circuit for the coil 221 of said relay for controlling the furnace-gas flow rate incorporates a make contact 1151 of the sensor 115 (Fig. 2) responsive to the 3 flow rate of gas which contact is closed while the rate flow of gas passing through the turbine 1 is within its specified limits.
A feed circuit for the coil 222 of said relay for starting the gas heater 20 incorporates a make contact 2202 of the auxiliary relay, a make contact 2211 of the relay for controlling the furnace-gas flow rate, a make contact 2012 of the relay for permitting the gas heater starting, these three ;` contacts being connected in series, a make contact 2221 of this gas-heater starting relay connected in parallel with the contacts 2202, 2211, and 2012, a break contact 2291 of the relay operative upon completion of the gas heater starting, and a break contact 2331 of the gas heater shut-down relay, both contacts 2291 and 2331 being connected in series with one another and with all the preceding contacts. Two make contacts (not shown in Fig. 7) of the gas-heater starting relay form the first and second outputs 124 and 125 (Fig. 2) of the gas-heating control unit 109.
A feed circuit for the coil 223 of said ignitor actu-ating relay incorporates a make contact 2222 of the gas-heater starting relay and a break contact 2251 of the ignitor switching-off relay connected in series with the contact 2222.
The coil 224 of the ignitor switching-off time relay is connec-ted in parallel with the coil 223 of the ignitor switching-on relay, a make contact of the latter (not shown in Fig. 7) forming the fourth output 127 of the gas-heating control unit 109 .

~ - 55 --, , ., , ~, :

2;~

A feed circuit for the coil 225 of said ignitor switching-oEf relay incorporates a make contact 2241 oi~ the ignitor switching-off time relay, a make contact 2252 of this ignitor switching-off relay, and a break contact 2332 of the gas-heater shut-down relay, the contacts 2252 and 2332 being connected in series to one another and in parallel with the contact 2241.
A feed circuit for the coil 226 of said relay for controlling the gas temperature at the ignitor outlet incor-porates a make contact 1171 of the sensor 117 (Fig. 2) responsive to gas temperature at the ignitor outlet, which contact is opened as the gas temperature exceeds its specified j lower limit corresponding to the gas ignition point.
`~ A feed circuit Eor the coil 227 of said relay for actuating the electric drive 42 to open the valve 41 incor-porates series-connected contacts, namely, a make contact 2261 of the gas-temperature control relay, a make contact ',5i'' 2253 of the ignitor switching-off relay, and a break contact 2311 of the generator-to-motor changeover relay. A make con--~ 20 tact (not shown in Fig. 7) of this relay for actuating the electric drive 42 to open the valve 41 forms the third output 12~ (Fig. 2) of the control unit 109.
. . , ~ ' A Eeed circuit for the coil 228 of said time relay `~i ' for the gas-heater starting incorporates a make contact 119 of the sensor 119 (Fig. 2) responsive to position of the valve 41, which contact is closed upon the opening of this valve, and a break contact 2292 of the gas-heater starting completion relay connected in series with the contact 1191.
A feed circuit for the coil 229 of said relay opera-tive upon completion of the starting cycle of the gas heater 20 incorporates a make contact 2281 of the time relay for the gas-heater starting, a make contact 2293 of this gas-heater ~q~3 starting completion relay connected in parallel with the con-tact 2281, a break contact 2333 of the gas-heater shut-down relay, and a break contact 2312 of the generator-to-motor changeover relay, these contacts 2333 and 2312 being connected in series with each other and with the contacts 2281 and 2293. Two break contacts (not shown in Fig. 7~ of the gas-heater starting completion relay ~orm the fifth output 128 ~ ~
and the eleventh output 138 (Fig. 2) of the control unit 109. !' i A feed circuit for the coil 230 of said relay for controlling the minimum flow rate of blast-furnace gas incor-~' porates a break contact 1211 of the sensor 121 (Fig. 2) 7 responsive to gas flow rate, which contact is opened as the rate of gas flow through the gas turbine 1 drops to its minimum valve at which the delivery of air to the gas heater ~ 20 is stopped.
i!~ A feed circuit for the coil 231 of said generator-.i to-motor changeover relay incorporates a make contact 2301 of , the minimum gas-flow rate control relay, a make contact 2313 of this generator-to-motor changeover relay, a break contact ,.:.
2212 of the furnace-gas flow rate control relay, these con-tacts 2313 and 2212 being connected in series with each other ~` and in parallel with the contact 2301, and a break contact ` 2203 of the auxiliary relay connected in series with the con-` tacts 2301, 221, and 2313.
A feed circuit 232 of said relay for actuating the electric drive 42 to close the valve 41 incorporates a make contact 2314 of the generator-to-motor changeover relay and a make contact 2334 of the gas-heater shut-down relay connected in parallel with the contact 2314. A make contact (not shown in Fig. 7) of this relay for actuating the electric drive 42 ; to close the valve 41 forms the eighth output 131 of the control unit 109.

Z~ `

A feed circuit 233 of the relay for shutting down the gas heater 20 incorporates a break contact 2262 of the relay for controlling the gas temperature at the outlet of the ignitor 21 (Fig. 1), a make contact 2254 of the ignitor switching-off relay connected in series with the contact 2262, a make contact 271 of the sensor 27 (Fig. 2? responsive to the furnace gas temperature at the inlet of the gas turbine 1, which contact, connected in parallel with the contacts 2262 and 2254, is closed as the gas temperature reaches its maxi-mum limit value at which the gas heater 20 is shut down, a break contact 272 vf the sensor 27, which contact is closed the gas temperature drops to its minimum limit at which the - i gas heater 20 is shut down, a make contact 2294 of the gas-~5 heater starting completion relay, the contacts 272 and 2294 , ., being connected in series with each other and in parallel with the contact 271, a make contact 2403 forming the seventh output 169 of the shut-down control unit 146 (Fig. 2), which : contact is connected in parallel with the contacts 272 and 2294, a make contact 2302 of the relay for controlling the minimum furnace-gas flow rate, a make contact 2384 forming the sixth output 168 of the shut-down control unit 146, the ; contacts 2302 and 2384 being connected in series with each other and in parallel with the contact 2403, and a make contact 2335 of this gas-heater shut-down relay connected in parallel with the contacts 2302 and 2384. A make contact of said push-button switch 219 is connected in series with the contacts 2262, 2254, 271, 272, 2294, 2403, 2384, 2302, and 2335.
Three make contacts (not shown in Fig. 7) of the relay for shutting down the gas heater 20 form the sixth, seventh, and tenth outputs 129, 130, and 137, and one break contact forms the ninth output 136 (Fig. 2) of the gas-heating control unit 109 .

~p~ 23 :;
Referring now to Fig. 8, said control unit 132 for changing over the regulator 12 (Fig. 1) of gas pressure under ; the top of the blast furnace 5 comprises a relay with a coil 234 for the changeover regulator 12, and a relay with a coil 235 for reducing load of the turbine 1.
- A feed circuit for the coil 234 of said regulator changeover relay incorporates a make contact 1411 of the sensor 141 (Fig. 2) responsive to the blast-furnace gas temperature at the inlet of the gas turbine 1, which contact is closed as the gas temperature reaches its minimum value at which the regulator 12 still can be switched over to the input of the rotor-speed regulating system 9, a break contact 2336 of the gas-heater shut-down relay, and a break contact 2385 forming the eighth output 173 (Fig. 2) of the shut-down control relay 146, these contacts 1141, 2336, and 2385 being series-connected. Make contacts (not shown in Fig. 8) of this regulator changeover relay form the first and second outputs 142 and 143 (Fig. 2~ of the changeover control unit 132.
A feed circuit for the coil 235 of said load-reducing relay incorporates a make contact 2337 of the gas-heater shut-down relay, a break contact 2295 of the gas-heater starting completion relay, and a make contact 1062 of the sensor 106 (Fig. 2) responsive to gas flow rate, which contact is closed as the rate of gas flow through the turbine 1 reaches its maximum possible value without the gas heater 20 being operative, the contacts 1062 and 2295 being connected in series with each other and in parallel with the contact 2337 A make and a break contacts (not shown in Fig. 8) of this load-reducing relay form, respectively, the third and fourth outputs 144 and 145 (Fig. 2) of the changeover control unit 132.

Reference is now made to Fig. 9, illustrating a ~1~3$~3 schematic circuit diagram of said shut-down control unit 146, shown in Fig. 2, which comprises a push-button switch 236 for stopping the installation, a push-button switch 237 for releasing the installation from its protections, a shut-down relay with a coil 238, a relay with a coil 239 for disconnec-ting the electric generator 6 from the power line (Fig. 1), and an emergency shut-down relay with a coil 240.
A feed circuit for the coil 238 of said shut-down relay incorporates a make contact 236 of the push-button switch for stopping the installation, a make contact 2073 of the relay operative for preparing the oil pump starting, a make contact 2381 of this shut-down relay, and a make contact 2401 of the emergency shut-down relay, the contacts 2073 and 2381 being connected in series with each other and in parallel with the contact 236, the contact 2401 being connected in parallel with the contact 2381.
The contact 2382 (see Fig. 4) of the shut-down relay is connected, respectively to the feed circuits of the coils 206 of the automatic-start relay and 213 of the instal-lation starting completion relay, and forms the first output161 (Fig. 2) o~ the shut-down control unit 146. A make con-tact (not shown in Fig. 9) of the shut-down relay forms the fourth output 166 (Fig. 2) of the unit 146. Another break ~' contact 2383 (see Fig. 7) of this relay is connected to the ' feed circuit of the coil 220 of the auxiliary re~ay in the control unit 109 and makes up the fifth output 167 of the ~- shut-down control unit 146. Another make contact 2384 (see Fig. 7) of this shut-down relay is connected in series with said contact 2302 in the feed circuit for the coil 233 of the gas-heater shut-down relay and forms the sixth output 168 (Fig. 2) of the shut-down control unit 146. Another break contact 2385 (see Fig~ 8) o~ this shut-down relay is connected r . - .

in series with said contacts 1411, and 2336 in the feed cir-cuit for the coil 234 of the regulator changeover relay and forms the eighth output 173 (Fig. 2) of the shut-down control unit 146. Another make contact (not shown in Fig. 9) of the -;~
shut-down relay form the tenth output 178 (Fig. 1) of the shut-down control unit 146.
A feed circuit for the coil 239 of said relay for disconnecting the electric generator 6 from the power line incorporates a make contact 2386 of the shut-down relay and a ~ ~
make contact 652 of the sensor 65 (Fig. 2~ responsive to posi- ~ -tion of the closing diaphragm gate 3 (Fig. 1), which contact is closed upon closure of this gate, both contacts 2386 and 652 being connected in series. One make contact 2391 (see Fig. 4) is connected in series with said contact 801 in the coil 208 of the oil pump shut-down time relay, forming the second output 162 (Fig. 2) of the shut-down control unit 146.
Another break contact (not shown in Fig. 9) forms the ninth ` output 175 (Fig. 2) of the shut-down control unit 146.
... ..
~ A feed circuit for the coil 240 of the emergency ; 20 shut-down relay incorporates a make contact 1511 of the sensor ~` 151 (Fig. 2) responsive to rotational speed of the rotor, . ;" :~ .
which contact is closed as the rotor speed reaches its maxi-,. ~
;~ mum limit, a make contact 273 of the second sensor 27 (Fig.
2) responsive to the blast-furnace gas temperature at the inlet of the gas turbine 1, a make contact 1581 of the sensor 158 (Fig. 2) responsive to the maximum temperature of the gas-~-~ turbine bearings and the electric-generator bearings, a make contact 1601 of the sensor 160 (Fig. 2) responsive to the maximum vibration of the gas-turbine and electric-generator bearings, a make contact 2402 of this emergency shut-down relay, a make contact 1531 of the sensor 153 (Fig. 2) respon-sive to oil pressure in the oiling system, which contact is , z~ ` :

closed as the oil pressure drops to its lower limit, and a break contact 1551 of the sensor 155 (Fig. 2) responsive to position of the valve 29, which contact is opened upon opening of said valve, said contacts 153, and 1551 being connected in series with one another and in parallel with the contacts 1511, 273, 1581, 1601 and 2402, which are connec-ted in parallel with each other, a break contact of said push-~utton switch 237 being connected in series with each of said contacts. The make contact 2403 (see Fig. 7) of the emergency shut-down relay is incorporated in the feed ~; circuit of the coil 233 of the gas-heater shut-down relay in sexies therewith and forms the seventh output 169 (Fig. 2) of the shut-down control unit 146. Another make contact (not shown in Fig. 9) of the emergency shut-down relay forms the ; ; , ` third output 165 (Fig. 2) of the shut-down control unit 146.

Referring now to Fig. 10, said control unit 176 for ~,, .
:'~ filling and emptying the installation, shown in Fig. 2, . ~ !
includes a switch 241 for actuating the filling and emptying ~ with contacts 2411, 2412, and 2413, and a relay with a coil `~; 20 242 for actuating the electric drive 30 of the valve 29 (Fig. 1).
~; A feed circuit for the coil 242 incorporates a make contact 2387 of the shut-down relay, which contact forms the tenth output 178 (Fig. 2) of the shut-down control unit 146. A make contact (not shown in Fig. 10) of this valve-actuating relay forms the second output 194 of the control unit 176.
This control unit 176 also has a relay with a coil 243 operative upon closure of the valve 29. A feed circuit for the coil 243 incorporates a make contact 802 of the sensor 80 (Fig. 2) responsive to position of said valve 29, which contact is closed upon closure thereof. The control unit 176 further has a relay with a coil 244 operative upon the opening of the valve 35 (Fig. 1), a feed circuit for the coil 244 incorporating a make contact 1831 of the sensor 183 (Fig. 2) responsive to position of said valve 35, which con-tact is closed upon opening thereof. The control unit 176 has a rela~ with a coil 245 operative upon closure of the ~
valve 38 (Fig. 1), a feed circuit for the coil 245 incorporat-- ing a make contact 1861 of the sensor 186 (Fig. 2) responsive r to position of said valve 38, which contact is closed upon closure thereof.
The control unit 176 also includes a relay with a ` coil 246 for actuating the electric drive 36 to close the valve 35 (Fig. 1), a relay with a coil 247 for actuating the electric drive 33 to open the valve 32 (Fig. 1), and a relay with a coil 248 for actuating the electric drive 39 to open the valve 38 (Fig. 1).
A feed circuit for the coil 246 incorporates a make contact 2431 of the relay operative upon closure of the valve 29 and a make contact 2411 of the switch 241 (not shown in Fig. 10) which is closed in the "emptying" position thereof, both contacts 2431 and 2411 being connected in series. A make contact 1821 of the sensor 182 (Fig. 2) responsive to position of the valve 35, which contact is closed upon closure thereof, and the coil 247 of the relay for actuating the electric drive 33 to open the valve 32 are connected in series with said contact 2411. A make contact 1911 o~ the sensor 191 (Fig. 2) responsive to position of the valve 32, which contact is closed upon opening thereof, and the coil 248 of the relay for actuating the electric drive 39 to open the valve 38 are connected in series with one another and in parallel with the contact 1821 and the coil 247. A
make contact tnot shown in Fig. 10) of said relay for ~9, ,Z~

actuating the electric drive 36 to close the valve 35 forms the third output 195 ~Fig. 2), a make contact (not shown in Fig. 10) of said relay for actuating the electric drive 33 to open the valve 32 forms the eighth output 200 (Fig. 2), and a make contact (also not shown in Fig. 10~ of said relay for actuating the electric drive 39 to open the valve 38 forms -;~
the seventh output 199 (Fig. 2~ of the control unit 176.
~ The control unit 176 includes a time relay with a ; coil 249 for emptying the installation. A feed circuit for the coil 249 incorporates a make contact 1871 of the sensor 187 (Fig. 2) responsive to position of the valve 38, which contact is closed upon opening thereof. ;
The control unit 176 also includes a relay with a coil 250 for actuating the electric drives 39 and 33 to close the valves 38 and 32. A feed circuit for the coil 250 incorporates a make contact 2412 of the switch 241, which is closed in the neutral position thereof, a make contact 2491 of said time relay for emptying the installation, connected in series with said contact 241, and a make contact 2441 of the relay operative upon the opening of the valve 35, which contact is connected in parallel with the contact 2491. Make contacts (not shown in Fig. 10~ of this relay for actuating the electric drives 39 and 33 to close the valves 38 and 32 form the fourth and the fifth outputs 196 and 197 (Fig. 2) of the control unit 176.
Furthermore, the control unit 176 has a relay with a coil 251 for actuating the electric drive 36 to open the valve 35. A feed circuit for the coil 251 incorporates a make contact 2451 of the relay operative upon closure of the valve 38, and a make contact 2413 of the switch 241, which is closed in the "filling" position thereof, both contacts 245 and 2413 being connected in series. A make contact 2442 of ,~ ~.
~ 64 -.,~C

~.

~$~3 .

the relay operative upon the opening of the valve 35 and the coil 247 of the relay for actuating the electric drive 33 of the valve 32 are connected in series with said contact 2413.
A make contact (not shown in Fig. 103 of the relay for actu-ating the electric drive 36 to open the valve 35 forms the sixth output 198 (Fig. 2) of the control unit 176.
The control unit 176 also has an output relay with a coil 252 whose feed circuit incorporates series-connected contacts, namely, a make contact 2432 of the relay operative upon closure of the valve 29, a make contact 2443 of the relay operative upon the opening of the valve 35, a make contact 2452 of the relay operative upon closure of the valve 38, and a make contact 1901 of the sensor 190 (Fig. 2) responsive to position of the valve 32, which contact is closed upon closure thereof. The make contact 2521 (see Fig. 3) of this output relay is connected to the feed circuit for the coil 202 of the relay operative for permitting the installation start-up in series with this coil 202 and with the contact 2011. This contact 2521 makes up the first out-put 192 (Fig. 2) of the control unit 176 for filling and emptying the installation.
The automatic control system according to the inven-tion operates as follows.
Initially, the system is actuated only if each of the sensors 51, 53, 55, 57, 59, 61, 63, 65, 67, 69 and 71 (see Fig. 2), responsive to the respective operational condi-tion of the installation, has been in a position indicative of its readiness to starting. Here, the output relay of the control unit 176 emits a signal indicative of that the installation is filled with blast-furnace gas, which is applied to the input 193 of the control unit 49. This control unit having operated, the input 73 of the control unit 72 and 2~

the input 112 of the control unit 109 receive signals permit-ting the start-up thereof, i.e. the relay coils 201 and 202 (Fig. 3) become energized and pick-up their respective con-tacts 2021 (Fig. 4) in the control unit 72 (Fig. 2) and 2012 (Fig. 7) in the control unit 109 (Fig. 2).
The control unit 72 is started up manually by depressing the push-button switch 205 "start" (Fig. 4). The relay with the coil 206 thereby becomes operative and latches itself until the completion of the gas turbine starting, simultaneously closing its contact 2062 in the feed circuit of the relay with the coil 207, which latches itself until the shut-down of the installation. This relay through its contact 2072 actuates the relay with the coil 209, which starts up the oil pump 8 (Fig. 2). This creates pressure in ~; the oiling system which, on reaching some value within specified operative limits, causes the sensor 76 to close its contact 761 (Fig. 4), placed in the feed circuit of the relay with the coil 210. Said relay with the coil 210 actuates the electric drive 30 (Fig. 2) of the valve 29 in the conduit 31. The valve 29 is opened, and blast-furnace gas is delivered to the installation. Upon completion of this opera-tion, the sensor 79 closes its contact 791' placed in the feed circuit of the relay with the coil 211. The coil 211 becomes energized and actuates the ventilator 7 (Fig. 2) in the cooling system of the electric generator 6 (Fig. 1).
This creates pressure in the air-cooling system which is sensed by the sensor 82, whose contact 821 becomes closed.
The closure of the contacts 821, which is placed in the feed circuit of relay with the coil 212, energizes it and thereby actuates the rotor-speed selector 10 (Fig. 2) to increase rotational speed of the rotor of the gas turbine 1 (Fig. 1).

Simultaneously, the contact 2121 (Fig. 4) is picked up by said relay to prepare the respective feed circuit for actuating the relay with the coil 213. The rotor-speed selector 10 acts on the closing diaphragm gate 3 and the control diaphragm gate 2 (Fig. 1~ so as to increase the rotor ~;peed. As the rotor rotational frequency reaches its value which is roughly equal to the electric-generator frequency, the sensor 84 responsive to rotational speed of the rotor opens its contact 841, placed in the feed circuit of the relay with the coil 209.
The relay renders inoperative the electric pump 8 (Fig. 2) and through its contact 2091 (Fig. 4) actuates the relay with the coil 213, which produces a signal indicative of the completion of the gas-turbine starting, actuates the synchronizing device 14 (Fig. 2), locks itself in until the installatlon shut-down, and through its contacts 2131 and 2132 (Fig. 4) disconnects the relays with the coils 206 and 212. On becoming de-energized, the relay with the coil 212 terminates speeding-up of the rotor through the rotor-speed selector 10 and sends a signal which is applied to the input ` 20 92 of the synchronizing control unit 91 for actuation thereof.
Simultaneously, the contact 2134 (Fig. 5), placed in the feed circuits of the relays with the coils 214 and 215, is closed, and the relay with the coil 215 actuates the rotor-speed selector 10 for increasing rotational speed of the rotor. When the electric-generator frequency hecomes equal to the power-line freqLlency, the device 14 through the switch 13 (Fig. 1) connects the electric generator 6 (Fig. 1) to the power line. To effect this, the signalling and inter-locking contact 95 of the switch 13, placed in the feed circuit of the relay with the coil 214, becomes closed and emits a signal which is applied to the input 94 (Fig. 2) of the control unit 91. Said relay with the coil 214 is thereby actuated and through its contact 2141 breaks the feed circuits of the relays with the coils 215 and 216.
If the synchronization has not occurred, the rotor-speed selector 10 is shifted to its extreme position for increased rotor speed. In this case, the contact 971 (Fig~ 5) of the sensor 97 is closed, whereupon the relay with the coil 217 is actuated and through its contact 2171 de-energizes the relay with the coil 215 and through its contact 2172 actuates the relay with the coil 216. The latter actuates the rotor-speed selector 10 to reduce rotational speed of the rotor to a value at which the synchronization is still possible. The `
contact 991 of the sensor 99 is opened. The relay with t~e coil 216 becomes de-energized thereby to terminate the rotor slowing-down through the rotor-speed selector 10.
The selector 10 is actuated to increase and reduce rotational speed of the rotor in its limits wherein the synchronization is possible until it is reached, whereupon the signalling and interlocking contact 95 is closed. That develops a signal which is directed from the output 104 of the control unit 91 to the input 103 of the control unit 102 for actuation thereof.
The contact 2142 (Fig. 6) in the feed circuit of the relay with the coil 218 is closed, and the rotor-speed selector 10 is actuated for load increase.
The selector 10 (see Fig. 1) opens the control diaphragm gate 3 for increasing the flow rate of gas passing through the turbine 1.
The input 110 (Fig. 2) of the gas-heating control unit 109 receives a signal from the output 111 of the control unit 102 to permit actuation of said control unit 109. When the rate of gas flow through the gas turbine 1 reaches its maximum permissible value at which the gas heater 20 is not rr ~
f~

started yet, the contact 1061 of the sensor 106 is opened.
At this, the relay, coil 21~, becomes de-energized and disconnects the rotor-speed selector 10.
The control unit 109 is actuated automatically as the flow rate of gas passing through the gas turbine reaches its value at which the gas heater 20 must be started. The input 114 (Fig. 2) o~ the control unit 109 then receives a signal from the sensor 115 responsive to gas flow rate. The relays, coils 220 and 221, in the control unit 109 become energized, and through the contacts 2202, 2212 and 2012 the relay with the coil 222 become actuated. This relay locks itself in until the gas-heater starting has been completed or the gas heater has been shut down. The control unit 109 emits, through its outputs 124 and 125 (Fig. 2), signals to open the valves 43 and 46 (Fig. 1), whereupon air and gaseous fuel are delivered to the ignitor 21. At the same time, the relay with the coil 223 is actuated through the contact 2222 (Fig. 7), actuating the ignitor 21 (Fig. 2) and the time relay with the coil 224. The gaseous fuel is ignited. If the ignition fails to occur, a protective system for the gas heater 20 is operated, which is described hereafter. Other-wise, the sensor 117 responsive to the temperature of gas at the outlet of the ignitor 21 (Fig. 1) closes its contact 117 when the gas temperature exceeds its minimum value corres-ponding to the gas ignition point. As a result, the relay, coil 226, is actuated. After timing out, the time relay, coil 224, picks up its contact 2241 and through it actuates the relay, coil 225. This relay breaks its contact 2251 and thereby disconnects the relay, coil 223, and the ignitor 21.
The relay, coil 227, becomes operative through the contacts ` 2261 and 2253 and actuates the electric drive 42. The latter opens the valve 41 (Fig. 1), which allows the air for igniting ~7 .. . . . .

2~

blast-furnace gas to pass into the gas heater 20, whereupon the blast-furnace gas is ignited. After the opening of the valve 41 has been completed, the contact 1191 (Fig. 7) of the sensor 119 becomes closed and energizes the coil 228.
After timing out, the time relay, coil 228, through its contact 2281 actuates the relay, coil 229, which develops a signal indicative of the completion of the gas-heater start-ing and actuates the regulator 23 of the blast-furnace gas temperature ahead of the gas turbine 1. At this time, the relays with the coils 222 and 228 become de-energized. If `~
the ignition of blast-furnace gas fails to occur, the protec-tive system for the gas heater 20 is operated as described hereafter.
Operation of the gas heater 20 results in increased gas temperature ahead of the gas turbine 1, whereas the tem-perature regulator 23, when actuated, sets up the gas tempera-ture there at its optimal value. The input 140 of the changeover control unit 132 receives a signal from the sensor 141 for actuation thereof. The closure of the sensor contact 1411 (Fig. 8) actuates the relay, coil 234, which switches over the pressure regulator 12 (Fig. 2) through the input-signal converter 11 to the input of the rotor-speed regulat-ing system 9 and actuates the rotor-speed selector 10 to increase the rotor speed up to its maximum value. Here, the sensor 97 opens its contact 972 thereby excluding repeated actuation of the load-increase control unit 102 during a temporary changeover of the blast furnaces 5 (Fig. 1) to operation at reduced gas pressure therein.
During the above-mentioned temporary changeover of the blast furnace 5 to operation at reduced gas pressure, the rate of gas flow through the turbine 1 drops, and the electric generator 6 is changed over to another operating ~` ., .

2~

mode, functioning as an electric motor. At this time, the sensor 121 closes its contact 1211 (Fig. 8), the relay with , the coil 230 becomes operative and picks up its contact 230 to actuate the relay, coil 231, which, upon energization, ~ latches itself and actuates the relay with the coil 232. The ! latter actuates the electric drive 42 (Fig. 2) to close the valve 41, whereupon the delivery of air to the gas heater 20 for burning the blast-furnace gas therein is shut off.
Simultaneously, the relay, coil 229, is disconnected through the opening of the contact 2312 (Fig. 8) and the temperature regulator 23 (Fig. 1) is shut down.
The temperature of blast-furnace gas ahead of the gas turbine 1 then decreases. The sensor 141 breaks its con-tact 1411 (Fig. 8), which de-energizes the relay, coil 234.
This relay switches over the pressure regulator 12 from the rotor-speed regulating system 9 to the input of the throttle device 4 for opening thereof.
The input 135 of the control unit 132 receives a signal from the output 138 of the control unit 109, whereupon the contact 2295 (Fig. 8) is closed and thus prepares the feed circuit of the relay with the coil 235 for actuation thereof.
After the ~last furnace 5 has been changed over to its normal operation, the flow rate of gas passing through ~; the gas turbine 1 increases, causing the sensor 106 responsive to gas flow rate to close its contact 1062 (Fig. 8). The relay, coil 235, becomes energized and acts through the input-signals converter 11 on the rotor-speed regulating system so as to reduce the flow rate of gas as much as possible to a value at which operation without the gas heater 20 is still permissible.

An increase in the rate flow of gas through the gas -2~
., turbine 1 is also sensed by the sensor 115, which closes its contact 1151 (Fig. 7), whereby the relay with the coil 221 ~;
becomes operative and disconnects through its contact 221 the relay with the coil 231. The relay, coil 227, is then actuated through the contact 2311 and actuates the electric drive 42 to open the valve 41 (Fig. 1). The air for burning blast-furnace gas is fed into the gas heater 20. The tempera-ture regulator 23 is then actuated~ The signal to the input 135 (Fig. 2) of the control unit 132 is interrupted, the contact 2295 (Fig. 8) is opened and the relay, coil 235, de-energized.
As the optimal temperature of gas ahead of the gas turbine 1 is reached, the pressure regulator 12 is switched over to the input of the rotor-speed regulating system 9.
The control system provides for the following pro-tections for the gas heater 20 to shut it down.
If the high-grade gaseous fuel fails to burn, there ~ ~-is no signal from the gas-temperature sensor 117 (Fig. 2).
The relays with the coils 226 and 227 (Fig. 7) are de-energized, and the contact 2262 in the feed circuit of the gas heater shut-down relay, coil 233, is closed.
If the temperature of blast-furnace gas ahead of the gas turbine 1 drops below its specified minimum value so that the gas fails to burn in the actuated gas heater 20, the sensor 27 closes its contact 271 in the feed circuit of said gas-heater shut-down relay, coil 233.
When the temperature of blast-furnace gas ahead of the gas turbine 1 exceeds its specified maximum value, the sensor 27 closes its contac~ 272 in the feed circuit of the relay, coil 233.

The gas heater 20 is also shut down in case of emergency. At this time, the input 172 (Fig. 2) of the X
, - 72 -~q3~3P~3 control unit 109 receives a signal whereby the contact 2403 (Fig. 7) is closed. ;-A regulator stopping of the gas heater 20 takes place only after the load of the gas turbine 1 has decreased.
At this time, the rate of gas flow through the gas turbine 1 drops whereupon the corresponding sensor 121 closes its con-tact 1211. The relay with coil 230 is thus actuated to pick up its contact 2302 in the feed circuit of said relay, coil 233. Simultaneously, the input 171 (Fig. 2) of the control unit 109 receives a signal from the output 168 of the control unit 146 whereby the contact 2384 in the feed circuit of said relay, coil 233, is closed.
As a result, in either of the above situations, the relay with the coil 233 becomes energized, locks itself in and, through its contacts 2331, 2332 and 2333, disconnects the feed circuits of the relays with the coils 222, 225 and 229. The relay with the coil 233 actuates the electric drives 44 and 47 (Fig. 2) to close the valves 43 and 46 (Fig.
1), thereby stopping the delivery of air and gaseous fuel to the ignitor 21. The relay, coil 232, becomes energized through the contact 2334 and actuates the electric drive 42 (Fig. 2) to close the valve 41 (Fig. 1) whereby air is shut off from the gas heater 20. The regulator 23 of the tempera-ture of gas ahead of the gas turbine 1 is disabled. The gas heater 20 is then shut down, whereupon the inputs 133 and 134 of the control unit 132 receive correspGnding signals from the outputs 136 and 137 (Fig. 2) of the control unit 109. The contact 2336 (Fig. 8) is opened to de-energize the relay, coil 234, which switches over the pressure regulator 12 from the rotor-speed regulating system 9 to the input of the throttle device 4 (Fig. 1) for its opening.

The relay, coil 235, becomes energized through the ~ - 73 -~ 3$~ ~3 contact 2337 (Fig. 8) and actuates th~ regulating system 9, connected through the device 11 (Fig. 1), to partly close the control diaphragm gate 2 for reduced load of the turbine 1.
The gas heater 20 is released from the above pro-tections manually by depressing the push-button switch 219, whose contact 219 (Fig. 7) is opened and disconnects the relay, coil 233.
The shut-down control unit 146 (Fig. 2) is actuated either manually by means of the push-button switch 236 (Fig.
9), or automatically by operation of one or several emergency protections. When one of the working characteristics of the gas turbine 1 (Fig. 1), checked by the sensors 27, 151, or 153 and 155 or 158, or 160, exceeds its specified limits, the respective contact 273, or 1511, or 1531 and 1551, or 1~81, ! ;
or 1601 of these sensors incorporated in the feed circuit of the relay, coil 240, is closed to actuate this relay, which latches itself and through its contact 2401 actuates the relay with the coil 238. The control unit 146 emits a signal to actuate the rotor-speed regulating system 9 for rapid closure of the control diaphragm gate 2 and the closing diaphragm gate 3 of the gas turbine 1 (Fig. 1). The input 172 (Fig. 2) of the control unit 109 receives a signal to shut down the gas heater 20, whereby the contact 2403 (Fig. 7) is closed and actuates the relay, with the coil 233, said relay disconnecting the gas heater 20.
The other operations are carried out in a manner similar to that taking place after the normal shut-down of the installation with the use of the push-button switch 236 (Fig.
9). The installation is released from the emergency protec-tion manually by depressing the push-button switch 237, whereby the contact 237 is opened to thereby de-energize the relay with the coil 240.

X

.. ... ...

L2~ ~

As the push-button switch 236 is depressed for shutting down the installation, the relay with the coil 238 is actuated and locks itself in until the oil pump 8 (Fig. 1) is stopped, and actuates the rotor-speed selector 10 (Fig. 2) to close the control and closing diaphragm gates 2 and 3 of the turbine 1 (Fig. 1). Upon complete closure of the closing diaphragm gate 3, the sensor 65 closes its contact 652 (Fig.
9) which actuates the relay with the coil 239, operating the switch 13 (Fig. 2) to disconnect the electric generator 6 from the power line. The input 83 (Fig. 2) of the start-up control unit 72, the inputs 170 and 171 of the gas-heating control unit 109, the input 174 of the changeover control ~ unit 132, and the input 177 of the filling and emptying con-j trol unit 176 receive signals from the outputs 161, 167, 168, 173 and 178 of the shut-up control unit 146. The contact 2382 (Fig. 4) is opened to disconnect the starting relays, coils 206 and 213. The contact 2382 (Fig. 4) is opened to ~ -disconnect the starting relays, coils 206 and 213. The con-tact 2383 (Fig. 7) is opened whereby the feed circuits of the relays actuating the gas heater 20 are disconnected. The contact 2384 is closed in the feed circuit of the relay with the coil 233, which shuts down the gas heater 20 after load of the gas turbine 1 has decreased owing to a drop in the flow rate of gas passing therethrough to its lower limit.
The contact 2385 (Fig. 8) is opened to disconnect the relay, coil 234, which switches over the regulator 12 (Fig. 1) from the regulating system 9 to the input of the throttle device

4 for its opening.
The filling and emptying control unit 176 (Fig. 2) is actuated. Upon closure of the contact 2387 (Fig. 10), the relay with the coil 242 becomes enérgized and actuates the electric drive 30 (Fig. 2) to close the valve 29 in the ,, 2~

conduit for the delivery of blast furnace gas to the installation. Upon completion of closure of the valve 29, the sensor 80 closes its contacts 801 (Fig. 4), placed in the feed circuit of the relay, coil 208, and 802 tFig. 10), placed in the feed circuit of the relay, coil 243. This latter relay becomes energized and picks up its contacts 2431 and 2432 to prepare the corresponding feed circuits for actuating the relays with the coils 246 and 252.
After the electric g~nerator 6 (Fig. 1) has been disconnected from the power line, the inputs 163 (Fig. 2) of the control unit 72 receives a signal from the output 162 of the control unit 146, whereby the contact 2391 (Fig. 4) is closed and the time relay with the coil 208 is actuated.
After timing out, this time relay breaks its contact 2081 and so disables the relay with the coil 207. The contact - 272 is then opened whereby the relay, coil 209, is de-energized to stop the oil pump 8 (Fig. 1). The output 148 (Fig. 2) of the control unit 72 emits a signal which is applied to the input 147 of the control unit 146. The con-tact 2073 (Fig. 9) becomes opened and disables the shut-down relay, coil 238.
When the installation needs to be opened after its shut-down, it is first emptied of blast-furnace gas. The emptying is initiated manually by means of the switch 241 (Fig. 10) which is shifted to its "opening" position.
The contact 2411 (Fig. 10) is then closed, the relay with the coil 246 is energized to actuate the electric drive 36 (Fig. 2) for opening the valve 35 (Fig. 1) in the conduit 37 for the discharge of blast-furnace gas from the installation.
As this operation is completed, the sensor 182 closes its contact 1821 (Fig. 10) whereby the relay, coil 247, c~ 76 -z~ ~

becomes energized and actuates the electric drive 33 (Fig. 2) to open the valve 32 (Fig. 1) in the conduit 34 for the dis-charge of the contaminated inert gas. As the opening of the valve 32 is completed, the sensor 191 closes its contact 191 (Fig. 10), whereby the relay with the coil 248 is energized.
ll~is relay actuates the electric drive 39 (Fig. 2) to open the valve 38 (Fig. 1) in the conduit 40 for the delivery of inert gas to the installation. The installation is then blown through with the inert gas.
The sensor 187 produces a signal indicative of the valve 38 being opened, which signal is applied to the input 185 (Fig. 2) of the control unit 176, whereby the time relay, coil 249 (Fig. 10), becomes operative. The time lag provided by this relay is set up depending on the time needed for emptying the installation. After timing out, the relay closes its contact 2491 and thus prepares the corresponding feed circuit for actuating the relay with the coil 250. When the switch 241 is shifted to its neutral position, the con-tact 2412 is closed, the relay, coil 250, becomes operative 20 and ~ctuates the electric drives 39 and 33 to close the valves 38 and 32.
Thereupon, the sensor 186 closes its contact 1861 (Fig. 10), the relay with the coil 245 becomes energized and picks up its contacts 2451 and 2452. The delivery of inert gas is terminated, Prior to starting, the installation must be filled with blast-furnace gas.
For this, the switch 241 is shifted into its "filling" position. The contact 2413 (Fig. 10) is closed, the 30 relay with the coil 251 becomes energized and actuates the electric drive 36 (Fig. 2) to open the valve 35 (Fig. 1) in the conduit 37 for the discharge of blast-furnace gas from 'X - 77 -.. . ~

2~i the installation. The sensor 183 then closes its contact 1831 (Fig. 10), which causes actuation of the relay with the coil 244. The relay picks up its contacts 2441, 2442~ and 2443. As a result, the relay with the coil 247 becomes operative and actuates the electric drive 33 tFig. 2) to open the valve 32 (Fig. 1).
After the installation has been filled with blast-furnace gas, the switch 241 (Fig. 10) is shifted to its neutral position by the operator. The contact 2412 is closed and through the closed contact 2441 operates the relay with the coil 250, which actuates the electric drive 33 to close the valve 32 (Fig. 1).
The valve 32 having been closed, the sensor 190 closes its contact 1901 (Fig. 1), whereupon the relay, coil 252, becomes energized and emits a signal indicative of the installation being filled with blast-furnace gas, which is applied to the input 193 of the start-up readiness control ` unit 49.
The control system according to the invention makes possible fully automatic control of an installation utilizing the energy of pressure of outgoing blast-furnace gas. This is accomplished by introducing a number of suitably int~r--.
connected functional control units, sensors, and servo-mechanisms, whereby the specified sequence of automatic opera-tions is ensured. The checking of the operations upon completion thereof excludes the upsetting of the operational sequence. This makes for higher reliability of the installa-tion and prevents damage to the equipment and hazards to the supervisory personnel.

Claims (9)

The embodiments of the invention in which an exclu-sive property or privilege is claimed are defined as follows:

1. A control system for an installation utilizing the energy of pressure of outgoing blast-furnace gas, comprising:
- an electric generator with a power-driven ventilator;
- a gas turbine having a rotor, used to rotate said electric generator;
- an air-cooling system for said electric generator;
- an oiling system for said gas turbine, having an oil pump, the system being also used for oiling said electric generator;
- a control diaphragm gate mounted on said gas turbine;
- a closing diaphragm gate mounted on said gas turbine;
- a throttle unit placed in parallel with said gas turbine;
- a system for regulating rotational speed of said gas-turbine rotor, said system being connected to said control and closing diaphragm gates;
- a selector of rotational speed for said rotor, the selector being part of said speed-regulating system;
- a regulator of pressure of blast-furnace gas under the top of the blast furnace;
- a device for converting input signals received from said furnace-gas pressure regulator, said device being connected to said throttle unit and to said rotor-speed regulating system;
- a switch for connecting and disconnecting said electric generator to and from an a.c. power line, said switch having a set of signalling and interlocking contacts;
- a device for synchronizing the rotor rotational frequency and the power line frequency, said synchronizing device having a first input connected to an output of said electric generator, a second input connected to said power line, and a first output electrically connected to said switch of said electric generator;
- a conduit for the delivery of blast-furnace gas to said gas turbine;
- a gas heater mounted on said conduit for the delivery of blast-furnace gas to said gas turbine, said gas heater being provided with an ignitor;
- a regulator of temperature of the blast-furnace gas delivered to said gas turbine;
- first sensor responsive to temperature of blast-furnace gas ahead of said gas turbine, said sensor being located on said conduit for the delivery of blast-furnace gas to said gas turbine downstream of said gas heater and connected to the input of said furnace-gas temperature regulator;
- a second sensor responsive to temperature of blast-furnace gas ahead of said gas turbine;
- a first valve, mounted in said conduit for the delivery of blast-furnace gas to the installation;
- an electric drive for said first valve;
- a conduit for the discharge of blast-furnace gas from said installation;
- a second valve, mounted on said conduit for the discharge of blast-furnace gas from the installation;
- an electric drive for said second valve;
- a conduit for the delivery of air to said gas heater;
- a third valve, mounted in a conduit for the delivery of air to said gas heater;
- an electric drive for said third valve;
- a conduit for the delivery of gaseous fuel to the ignitor of said gas heater;
- a fourth valve mounted in said conduit for the delivery of gaseous fuel to the ignitor of said gas heater;
- an electric drive for said fourth valve;

- a conduit for the delivery of inert gas to said installa-tion;
- a fifth valve, mounted in said conduit for the delivery of inert gas to the installation;
- an electric drive for said fifth valve;
- a conduit for the discharge of the contaminated inert gas from said installation;
- a sixth valve, mounted in said conduit for the discharge of the contaminated inert gas from the installation;
- an electric drive for said sixth valve;
- a conduit for the delivery of air to said ignitor of said gas heater;
- a seventh valve, mounted in said conduit for the delivery of air to said ignitor;
- an electric drive for said seventh valve;
- a control unit for checking the installation for start-up readiness, having a number of inputs and outputs;
- a sensor responsive to position of said third valve, pro-ducing a signal indicative of its being closed, which sensor is connected to a first of said inputs of said readiness control unit;
- a sensor responsive to position of said seventh valve, pro-ducing a signal indicative of its being closed, which sensor is connected to a second of said inputs of said readiness control unit;
- a sensor responsive to position of said fourth valve, pro-ducing a signal indicative of its being closed, which sensor is connected to a third of said inputs of said readiness control unit;
- a sensor responsive to air pressure ahead of said third valve, producing a signal indicative of the air pressure being within its operative limits, which sensor is connected to a fourth of said inputs of said readiness control unit;
- a sensor responsive to air pressure ahead of said seventh valve, producing a signal indicative of the air pressure being within its operative limits, which sensor is connected to a fifth of said inputs of said readiness control unit;
- a sensor responsive to gaseous-fuel pressure ahead of said fourth valve, producing a signal indicative of the gaseous-fuel pressure being within its operative limits, which sensor is connected to a sixth of said inputs of said readiness control unit;
- a sensor responsive to oil level in the oiling system of said gas turbine, producing a signal indicative of the oil level being within its operative limits, said sensor being connected to a seventh of said inputs of said readiness control unit;
- a sensor responsive to position of said closing diaphragm gate, producing a signal indicative of its closure, which sensor is connected to an eighth of said inputs of said readiness control unit;
- a sensor responsive to position of said control diaphragm gate, producing a signal indicative of its closure, which sensor is connected to a ninth of said inputs of said readi-ness control unit;
- a sensor responsive to position of said rotor-speed selector, producing a signal indicative of its initial posi-tion, which sensor is connected to a tenth of said inputs of said readiness control unit;
- a sensor responsive to position of said device for convert-ing input signals received from said regulator of gas pressure under the blast-furnace top, producing a signal indicative of said converting device being in its initial position, which sensor is connected to an eleventh of said inputs of said readiness control unit;
- a start-up control unit having a number of inputs and outputs;
- a first input of said start-up unit being connected to a first output of said readiness control unit;
- a sensor responsive to oil pressure in said oiling system of said gas turbine, producing a signal indicative of the oil pressure being within its operative limits, which sensor is connected to a second of said inputs of said start-up control unit;
- a sensor responsive to position of said first valve, pro-ducing a signal indicative of its opened position, which sensor is connected to a third of said inputs of said start-up control unit;
- a sensor responsive to position of said first valve, pro-ducing a signal indicative of its closed position, which sensor is connected to a fourth of said inputs of said start-up control unit;
- a sensor responsive to air pressure in said cooling system of the electric generator, producing a signal indicative of the air pressure being of a specified value, which sensor is connected to a fifth of said inputs of said start-up control unit;
- a sensor responsive to rotational speed of the rotor, pro-ducing a signal indicative of the rotor rotational frequency reaching a value roughly equal to the electric-generator synchronizing frequency, which sensor is connected to a sixth of said inputs of said start-up control unit;
- a first of said outputs of said start-up control unit being electrically connected to said oil pump;
- a second of said outputs of said start-up control unit being electrically connected to said electric drive of said first valve;
- a third of said outputs of said start-up control unit being electrically connected to said power-driven ventilator;
- a fourth of said outputs of said start-up control unit being electrically connected to said rotor-speed selector;
- a fifth of said outputs of said start-up control unit being electrically connected to a third input of said synchronizing device;
- a control unit for synchronizing the electric-generator frequency and the power-line frequency, said unit having a number of inputs and outputs;
- a first of said inputs of said synchronizing control unit being connected with a sixth of said outputs of said start-up control unit;
- a second of said inputs of said synchronizing control unit being connected with said first signalling and interlocking contact of said switch for said electric generator, which contact emits a signal indicative of the electric generator being connected to the power line;
- a sensor responsive to position of said rotor-speed selector, producing a signal indicative of the selector being shifted to its extreme position for increased rotor speed, which sensor is connected to a third of said inputs of said synchronizing control unit;
- a sensor responsive to rotational speed of the rotor, pro-ducing a signal indicative of the minimum rotor speed at which the electric-generator frequency can be synchronized with the power line frequency, which sensor is connected to a fourth of said inputs of said synchronizing control unit;
- a first of said outputs of said synchronizing control unit being connected to said rotor-speed selector to increase rotational speed of the rotor of said gas turbine;

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- a second of said outputs of said synchronizing control unit being connected to said rotor-speed selector to reduce rotational speed of the rotor of said gas turbine;
- a control unit for increasing load of the gas turbine, said unit having a number of inputs and outputs;
- a first of said inputs of said load-increase control unit being connected with a third of said outputs of said synchron-izing control unit;
- a sensor responsive to the flow rate of furnace gas, pro-ducing a signal indicative of the maximum rate of gas flow through said gas turbine without operating the gas heater, which sensor is connected to a second of said inputs of said load-increase control unit;
- said sensor responsive to position of said rotor-speed selector, producing a signal indicative of the selector being shifted to its extreme position for increased rotor speed, said sensor being connected to a third of said inputs of said load-increase control unit;
- a first of said outputs of said load-increase control unit being connected to said rotor-speed selector;
- a control unit for controlling the heating of blast-furnace gas, said unit having a number of inputs and outputs;
- a first of said inputs of said gas-heating control unit being connected to a second of said outputs of said load-increase control unit;
- a second of said inputs of said gas-heating control unit being connected with a second of said outputs of said readi-ness control unit;
- a sensor responsive to the flow rate of furnace gas, pro-ducing a signal indicative of the rate of gas flow through said gas turbine reaching its value at which the gas heater is actuated, which sensor is connected to a third of said inputs of said gas-heating control unit;
- a sensor responsive to temperature of gas at the outlet of said ignitor, producing a signal indicative of the gas temperature exceeding its ignition point, which sensor is connected to a fourth of said inputs of said gas-heating control unit;
- a sensor responsive to position of said third valve, pro-ducing a signal indicative of its opened position, which sensor is connected to a fifth of said inputs of said gas-heating control unit;
- a sensor responsive to the flow rate of furnace gas, pro-ducing a signal indicative of the minimum rate of gas flow through the gas turbine at which the delivery of air to the gas heater is stopped, which sensor is connected to a sixth of said inputs of said gas-heating control unit;
- said second sensor responsive to the blast-furnace gas temperature ahead of said gas turbine, producing respective signals indicative of the minimum and maximum gas temperatures at which said gas heater is shut down, said sensor being pro-vided with two outputs connected respectively to a seventh and an eighth inputs of said gas-heating control unit;
- a first of said outputs of said gas-heating control unit being electrically connected to said electric drive of said seventh valve for its opening;
- a second of said outputs of said gas-heating control unit being electrically connected to said electric drive of said fourth valve for its opening;
- a third of said outputs of said gas-heating control unit being electrically connected to said electric drive of said third valve for its opening;
- a fourth of said outputs of said gas-heating control unit being electrically connected to said ignitor;

- a fifth of said outputs of said gas-heating control unit being electrically connected to said regulator of gas tempera-ture ahead of said gas turbine for switching it "on" and "off";
- a sixth of said outputs of said gas-heating control unit being electrically connected to said electric drive of said seventh valve for its closure;
- a seventh of said output of said gas-heating control unit being electrically connected to said electric drive of said fourth valve for its closure;
- an eighth of said outputs of said gas-heating control unit being electrically connected to said electric drive of said third valve for its closure;
- a control unit for changing over the regulator of gas pressure under the blast-furnace top, which is used to con-nect and disconnect an output of said regulator through said input-signal converting device to an input of said rotor-speed regulating system or to an input of said throttle unit of said blast furnace, said control unit having a number of inputs and outputs;
- a first of said inputs of said changeover control unit being connected with a ninth of said outputs of said gas-heating control unit;
- second of said inputs of said changeover control unit being connected to a tenth of said outputs of said gas-heating control unit;
- a third of said inputs of said changeover control unit being connected with an eleventh of said outputs of said gas-heating control unit;
- a fourth of said inputs of said changeover control unit being connected to said sensor responsive to furnace-gas flow rate, which produces a signal indicative of the maximum rate of gas flow through said gas turbine with said gas heater being inoperative;
- a sensor responsive to gas temperature ahead of said gas turbine, producing a signal indicative of the minimal tempera-ture of the gas in said turbine at which said pressure regula-tor is connected to said input of said rotor-speed regulator, which sensor is connected to a fifth of said inputs of said changeover control unit;
- a first of said outputs of said changeover control unit being electrically connected to said rotor-speed selector;
- a second of said outputs of said changeover control unit being electrically connected to said furnace-gas pressure regulator for connection and disconnection thereof through said input-signal converting device to the input of said speed-regulating system;
- a third of said outputs of said changeover control unit being electrically connected to said output of said furnace-gas pressure regulator for connection and disconnection thereof to the input of said throttle unit of said blast furnace;
- a fourth of said outputs of said changeover control unit being connected to the input of said speed-regulating system through said input-signal converting device for transmitting a signal to reduce load of said gas turbine;
- a shut-down control unit having a number of inputs and outputs;
- a first of said inputs of said shut-down control unit being connected with a seventh of said outputs of said start-up control unit;
- said sensor responsive to position of said closing dia-phragm gate, producing a signal indicative of its closed position and connected to a second of said inputs of said shut-down control unit;
- a sensor responsive to rotational speed of the rotor, pro-ducing a signal indicative of the maximum rotor speed, which sensor is connected to a third of said inputs of said shut-down control unit;
- a sensor responsive to oil pressure in the oiling system, producing a signal indicative of the oil pressure dropping to its minimal value, which sensor is connected to a fourth of said inputs of said shut down control unit;
- a sensor responsive to position of said first valve, pro-ducing a signal indicative of its opening position, which sensor is connected to a fifth of said inputs of said shut-down control unit;
- said second sensor responsive to the blast-furnace gas temperature ahead of said gas turbine being connected to a sixth of said inputs of said shut-down control unit;
- a sensor responsive to the maximum temperature of bearings of said gas turbine and said electric generator, which sensor is connected to a seventh of said inputs of said shut-down control unit;
- a sensor responsive to vibration of bearings of said gas turbine and said electric generator, which sensor is connec-ted to an eighth of said inputs of said shut-down control unit;
- a first of said outputs of said shut-down control unit being connected to a seventh of said inputs of said start-up control unit;
- a second of said outputs of said shut-down control unit being connected to an eighth of said inputs of said start-up control unit;
- a third of said outputs of said shut-down control unit being electrically connected to the input of said rotor-speed regulating system for rapid opening and closure of said con-trol and closing diaphragm gates;
- a fourth of said outputs of said shut-down control unit being electrically connected to said rotor-speed selector to transmit a signal thereto for its return to the initial posi-tion;
- a fifth of said outputs of said shut-down control unit being connected to a ninth of said inputs of said gas-heating control unit;
- a sixth of said outputs of said shut-down control unit being connected to a tenth of said inputs of said gas-heating control unit;
- a seventh of said outputs of said shut-down control unit being connected to an eleventh of said inputs of said gas-heating control unit;
- an eighth of said outputs of said shut-down control unit being connected to a sixth of said inputs of said synchroniz-ing control unit;
- a ninth of said outputs of said shut-down control unit being electrically connected to said switch of said electric generator;
- a control unit for controlling the filling and emptying of the installation, said unit having a number of inputs and outputs;
- a first of said inputs of said filling and emptying con-trol unit being connected with a tenth of said inputs of said shut-down control unit;
- said sensor responsive to position of said first valve, producing a signal indicative of its closed position, said sensor being connected to a second of said inputs of said filling and emptying control unit;
- a sensor responsive to position of said second valve, producing a signal indicative of its closed position, which sensor is connected to a third of said inputs of said filling and emptying control unit;
- a sensor responsive to position of said second valve, pro-ducing a signal indicative of its opened position, which sensor is connected to a fourth of said inputs of said fill-ing and emptying control unit;
- a sensor responsive to position of said fifth valve, pro-ducing a signal indicative of its being closed, which sensor is connected to a fifth of said inputs of said filling and emptying control unit;
- a sensor responsive to position of said fifth valve, pro-ducing a signal indicative of its opened position, which sensor is connected to a sixth of said inputs of said fill-ing and emptying control unit;
- a sensor responsive to position of said sixth valve, pro-ducing a signal indicative of its closed position, which sensor is connected to a seventh of said inputs of said filling and emptying control unit;
- a sensor responsive to position of said sixth valve, pro-ducing a signal indicative of its opened position, which sensor is connected to an eighth of said inputs of said filling and emptying control unit;
- a first of said outputs of said filling and emptying con-trol unit being connected to a twelfth of said inputs of said readiness control unit;
- a second of said outputs of said filling and emptying con-trol unit being electrically connected to said electric drive of said first valve for its closure;
- a third of said outputs of said filling and emptying con-trol unit being electrically connected to said electric drive of said second valve for its closure;

- a fourth of said outputs of said filling and emptying con-trol unit being electrically connected to said electric drive of said fifth valve for its closure;
- a fifth of said outputs of said filling and emptying con-trol unit being electrically connected to said electric drive of said sixth valve for its closure;
- a sixth of said outputs of said filling and emptying con-trol unit being electrically connected to said electric drive of said second valve for its opening;
- a seventh of said outputs of said filling and emptying control unit being electrically connected to said electric drive of said fifth valve for its opening;
- an eighth of said outputs of said filling and emptying control unit being electrically connected to said electric drive of said sixth valve for its opening.

2. A control system as claimed in claim 1, wherein said control unit for checking the installation for start-up readiness comprises:
- a relay operative for permitting the starting of the gas heater, a feed circuit for a coil of this relay incorporating:
- a make contact of said sensor responsive to position of said third valve, which contact is closed upon closure of this valve;
- a make contact of said sensor responsive to position of said seventh valve, which contact is closed upon closure of this valve, said contact being connected in series with said make contact of said sensor responsive to position of said third valve;
- a make contact of said sensor responsive to position of said fourth valve, which contact is closed upon closure of this valve, said contact being connected in series with said make contact of said sensor responsive to position of said seventh valve;
- a make contact of said sensor responsive to air pressure ahead of said third valve, which contact is closed with the air pressure being within its operative limits, said contact being connected in series with said make contact of said sensor responsive to position of said fourth valve;
- a make contact of said sensor responsive to air pressure ahead of said seventh valve, which contact is closed with the air pressure being within its operative limits, said con-tact being connected in series with said make contact of said sensor responsive to air pressure ahead of said third valve;
- a make contact of said sensor responsive to gaseous-fuel pressure ahead of said fourth valve, which contact is closed with the gaseous-fuel pressure being within its operative limits, said contact being connected in series with said make contact of said sensor responsive to air pressure ahead of said seventh valve;
- a make contact of this relay for permitting the starting of the gas heater forming the second of said output of the readiness control unit;
- a relay operative for permitting the start-up of the installation a feed circuit for a coil of this relay incor-porating:
- a make contact of said sensor responsive to oil in said oiling system, which contact is closed with the oil level being within its operative limits;
- a make contact of said sensor responsive to position of said closing diaphragm gate, which contact is closed upon closure of this gate, said contact being connected in series with said make contact of said sensor responsive to oil level;

- a make contact of said sensor responsive to position of said control diaphragm gate, which contact is closed upon closure of this gate, said contact being connected in series with said make contact of said sensor responsive to position of said closing diaphragm gate;
- a make contact of said sensor responsive to position of said rotor-speed selector, which contact is closed with the rotor-speed selector being in its initial position, said con-tact being connected in series with said make contact of said sensor responsive to position of said control diaphragm gate;
- a make contact of said sensor responsive to position of said device for converting input signals coming from said regulator of gas pressure under the blast-furnace top, which contact is closed with said converting device being in its initial position, said contact being connected in series with said make contact of said sensor responsive to position of said rotor-speed selector;
- a make contact of this relay operative for permitting the starting of the gas heater, which contact is connected in series with said make contact of said sensor responsive to position of said input-signal converting device;
- a make contact of an output relay of said filling and emptying control unit, which contact is connected in series with said make contact of said relay operative for permitting the starting of the gas heater;
- a make contact of said relay operative for permitting the start-up of the installation forming said first output of said readiness control unit.

3. A control system as claimed in claim 2, wherein said start-up control unit comprises:
- a push-button "start" switch;
- an automatic-start relay, a feed circuit for a coil of this relay incorporating:
- a make contact of said push-button "start" switch;
- a make contact of said relay operative for permitting the start-up of the installation, said contact being connected in series with said make contact of said push-button switch "start";
- a make contact of said automatic-start relay, which is connected in parallel with said make contact of said push-button "start" switch and with said make contact of said relay operative for permitting the start-up of the installa-tion;
- a break contact of a relay operative upon completion of the installation starting, said contact being connected in series with said make contact of said relay operative for permitting the installation starting;
- a break contact connected in series with said make con-tact of said relay operative upon completion of the installa-tion starting, said contact forming the first output of said start-up control unit;
- a relay operative for preparing the starting of said oil pump, a feed circuit for a coil of said relay incorporating:
- a make contact of said automatic-start relay;
- a make contact of said relay operative for preparing the starting of the oil pump, said contact being connected in parallel with said make contact of the automatic-start relay;
- a make contact of said relay for preparing the oil pump starting and forming the seventh output of said start-up control unit;
- a break contact of a time relay for stopping the oil pump, said contact being connected in series with said make con-tact of the automatic-start relay;
- said time relay for stopping the oil pump, a feed circuit for a coil of this relay incorporating:
- a make contact of said sensor responsive to position of said first valve, which contact is closed upon closure thereof;
- a make contact connected in series with said make contact of said sensor responsive to position of said first valve, said contact forming said second output of said shut-down control unit;
- a relay for controlling said oil pump, a feed circuit for a coil of this relay incorporating:
- a second make contact of the relay operative for preparing the oil-pump starting;
- a break contact of said sensor responsive to rotational speed of the rotor, which contact is opened as the rotor rotational frequency reaches a value roughly equal to the synchronizing frequency of the electric generator, said contact being connected in series with said second make contact of said relay operative for preparing the starting of the oil pump;
- a make contact of said relay for preparing the oil pump starting, being the first output of the start-up unit;
- a relay for actuating the respective electric drive to open said first valve, a feed circuit for a coil of this relay incorporating:
- a make contact of said sensor responsive to oil pressure in the oiling system of the gas turbine, which contact is closed while the oil pressure is within its operative limits;
- a third make contact of said automatic-start relay, which is connected in series with said make contact of said sensor responsive to oil pressure in said oiling system;
- a make contact of said relay for actuating the electric drive to open said first valve, forming said second output of said start-up control unit;
- a relay for actuating the power-driven ventilator, a feed circuit for a coil of this relay incorporating:
- a make contact of said sensor responsive to position of said first valve, which contact is closed upon closure of this valve;
- a make contact of this relay for actuating the power-driven ventilator forming said third output of said start-up control unit;
- a relay for actuating the rotor-speed selector, a coil of this relay being connected in parallel with said coil of said ventilator-actuating relay, a feed circuit for this coil incorporating:
- a make contact of said sensor responsive to air pressure in the electric-generator cooling system, which contact is closed as the air pressure therein reaches its specified value;
- a break contact of a relay operative upon completion of the installation starting, which contact is connected in series with the make contact of said sensor responsive to air pressure in the electric-generator cooling system;
- a make contact of said relay for actuating the rotor-speed selector forming said fourth output of said start-up control unit;
- said relay operative upon completion of the installation starting, a feed circuit for a coil of said relay incorpor-ating:
- a break contact of said relay for actuating the oil pump;
- a make contact of said relay for actuating the rotor-speed selector, which is connected in series with said break con-tact of said relay for controlling the oil pump;
- a make contact of said relay operative upon completion of the installation starting, which is connected in parallel with said break contact of said oil-pump controlling relay and with said make contact of said selector-actuating relay;
- a break contact connected in series with said make contact of said relay operative upon completion of the installation starting, said contact forming said first output of said shut-down control relay;
- two make contacts of this relay operative upon completion of the installation starting forming said fifth and sixth outputs of said start-up control unit.

4. A control system as claimed in claim 3, wherein said synchronizing control unit comprises:
- a relay-repeater for a signalling and interlocking contact of said switch of said electric generator, a feed circuit for a coil of this relay incorporating:
- a make contact of the relay operative upon completion of the installation starting;
- said make signalling and interlocking contact of said electric-generator switch, which contact is connected in series with said make contact of the relay operative upon completion of the installation starting;
- a relay for actuating the rotor-speed selector to increase rotational speed of the rotor, a coil of said relay being connected in parallel with said coil of said relay-repeater for the signalling and interlocking contact of said electric-generator switch, a feed circuit for this coil incorporating:
- a break contact of said relay-repeater for the signalling and interlocking contact of said electric-generator switch;
- a break contact of a relay for actuating the rotor-speed selector to reduce the rotor speed, which contact is connected in series with said break contact of the relay-repeater for the signalling and interlocking contact of said electric-generator switch;
- a break contact of a relay-repeater for said sensor respon-sive to position of the rotor-speed selector, which contact is connected in series with said break contact of said relay for actuating the rotor-speed selector to reduce the rotor speed;
- said relay for actuating the rotor speed selector to reduce rotational speed of the rotor, a coil of this relay being connected in parallel with the coil of said relay for actuating the rotor-speed selector to increase the rotor speed, and with said two contacts, viz., the break contact of said relay actuating the rotor-speed selector to reduce the rotor speed and the break contact of the relay-repeater for said sensor responsive to position of the rotor-speed selec-tor, a feed circuit for this coil incorporating:
- a make contact of said sensor responsive to rotational speed of the rotor, which contact is closed as the minimum speed at which the electric-generator frequency can be syn-chronized with the power-line frequency is exceeded;
- a make contact of the relay-repeater for the sensor respon-sive to position of the rotor-speed selector, which contact is connected in series with said make contact of said sensor responsive to rotational speed of the rotor;
- a make contact of this relay for actuating the rotor-speed selector to reduce the rotor speed, which contact is connected in parallel with said make contact of the relay-repeater for the sensor responsive to position of the rotor-speed selector;
- said relay-repeater for the sensor responsive to position of the rotor-speed selector, a feed circuit for a coil of said relay incorporating:
- a make contact of said sensor responsive to position of the rotor-speed selector, which contact is closed with the selector being shifted to its extreme position for increased rotor speed;
- a make contact of said relay for actuating the rotor-speed selector to increase the rotor speed forming the first output of said synchronizing control unit;
- a make contact of said relay for actuating the rotor-speed selector to reduce the rotor speed forming the second output of said synchronizing control unit;
- a make contact of said relay-repeater for the signalling and interlocking contact of the electric-generator switch forming the third output of said synchronizing control unit.

5. A control system as claimed in claim 4, wherein said load-increase control unit comprises a relay operative for increasing load of the gas turbine, a feed circuit for a coil of said relay incorporating:
- a make contact of the relay-repeater for the signalling and interlocking contact of the electric-generator switch;
- a break contact of said sensor responsive to furnace-gas flow rate, which contact is opened as the rate of gas flow through said gas turbine reaches its maximum value with the gas heater being inoperative, said contact being connected in series with said break contact of the relay-repeater for the signalling and interlocking contact of said electric-generator switch;
- a break contact of said sensor responsive to position of the rotor-speed selector, which contact is opened with the selector being shifted to its extreme position for increased rotor speed, said contact being connected in series with said break contact of said sensor responsive to the flow rate of furnace gas;
- two make contacts of said load-increase relay forming the first and second outputs of said load-increase control unit.

6. A control system as claimed in claim 5, wherein said gas-heating control unit comprises:
- a push-button switch for releasing said gas heater from protections;
- an auxiliary relay, a feed circuit for a coil of said relay incorporating:
- a make contact of said load-increase relay;
- a make contact of this auxiliary relay, which is connected in parallel with said make contact of said load-increase relay;
- a break contact connected in series with said make con-tact of said load-increase relay, said contact forming the fifth output of said shut-down control unit;
- a relay for controlling the flow rate of furnace gas, a feed circuit for a coil of said relay incorporating:
- a make contact of said sensor responsive to the flow rate of furnace gas, which contact is closed as the rate of gas flow through the gas turbine reaches a value at which the gas heater is actuated;
- a relay for starting the gas heater, a feed circuit for a coil of said relay incorporating:
- a make contact of said auxiliary relay;
- a make contact of said relay for controlling the flow rate of furnace gas, connected in series with said make contact of said auxiliary relay;
- a make contact of the relay operative for permitting the gas-heater starting, connected in series with said make contact of the relay for controlling the flow rate of furnace gas;
- a make contact of said relay for starting the gas heater, which contact is connected in series with said three contacts, viz. the make contact of said auxiliary relay, the make con-tact of said relay for controlling furnace-gas flow rate, and the make contact of said relay operative for permitting the gas-heater starting;
- a break contact of said relay operative upon completion of the gas-heater starting, which contact is connected in series with said make contact of the relay operative for permitting the gas-heater starting;
- a break contact of a relay for shutting down the gas heater, which contact is connected in series with said break contact of the relay operative upon completion of the gas-heater starting;
- two make contacts of said relay for starting the gas heater, forming the first and second outputs of said gas-heating control unit;
- a relay for actuating the ignitor, a feed circuit for a coil of this relay incorporating:
- a second make contact of said relay for starting the gas heater;
- a break contact of a relay for switching off the ignitor, which contact is connected in series with said second make contact of said relay for starting the gas heater;
- a coil of a time relay for switching off the ignitor being connected in parallel with said coil of said relay for actu-ating the ignitor;
- a make contact of this relay for actuating the ignitor forming the fourth output of said gas-heating control unit;
- said relay for switching off the ignitor, a feed circuit for a coil of this relay incorporating:
- a make contact of said time relay for switching off the ignitor;

- a make contact of this relay for switching off the ignitor which is connected in parallel with said make contact of said time relay for switching off the ignitor;
- a break contact of the relay for shutting down the gas heater, which is connected in series with said make contact of the relay for switching off the ignitor;
- a relay for controlling the gas temperature at the outlet of the ignitor, a feed circuit for a coil of this relay incorporating: .
- a make contact of said sensor responsive to the gas temper-ature at the outlet of the ignitor, which contact is closed as the gas temperature exceeds its ignition point;
- a relay for actuating the electric drive to open the third valve, a feed circuit for a coil of this relay incorporating:
- a make contact of the relay for controlling the furnace-gas temperature at the outlet of the ignitor;
- a make contact of the relay for switching off the ignitor, which contact is connected in series with said make contact of the relay for controlling the furnace gas temperature at the outlet of the ignitor;
- a break contact of a relay for changing over the electric generator to motor operation, which contact is connected in series with said make contact of said relay for switching off the ignitor;
- a make contact of said relay for actuating the electric drive to open the third valve forming the third output of said gas-heating control unit;
- a time relay for starting the gas heater, a feed circuit for a coil of this relay incorporating:
- a make contact of said sensor responsive to position of said third valve, which contact is closed upon its opening;
- a break contact of the relay operative upon completion of the gas-heater starting which contact is connected in series with said make contact of the sensor responsive to position of the third valve;
- said relay operative upon completion of the gas-heater starting cycle, a feed circuit for a coil of said relay incorporating:
- a make contact of the time relay for starting the gas heater;
- a make contact of this relay operative upon completion of the gas-heater starting cycle, which contact is connected in parallel with said make contact of the gas-heater starting time relay;
- a break contact of the gas-heater shut-down relay, which is connected in series with said make contact of the gas-heater starting time relay;
- a break contact of said generator-to-motor changeover relay, which is connected in series with said break contact of the gas-heater shut-down relay;
- two break contacts of said relay operative upon completion of the gas-heater starting cycle forming the fifth and eleventh outputs of said gas-heating control unit;
- a relay for controlling the minimum flow rate of gas, a feed circuit for a coil of said relay incorporating:
- a break contact of said sensor responsive to the flow rate of gas, which contact is opened as the rate of gas flow through the gas turbine exceeds its minimal value at which the delivery of air to the gas heater is stopped;
- said relay for changing over the electric generator to motor operation, a feed circuit for a coil of said relay incorporating:
- a make contact of said relay for controlling the minimum flow rate of gas;

- a make contact of this generator-to-motor changeover relay, which contact is connected in parallel with said make contact of said relay for controlling the minimum flow rate of gas;
- a break contact of said relay for controlling the minimum gas flow rate, which contact is connected in series with said third make contact of said generator-to-motor changeover relay;
- a make contact of the auxiliary relay, which contact is connected in series with said make contact of said relay for controlling the minimum flow rate of gas;
- a relay for actuating the respective electric drive to close the third valve, a feed circuit for a coil of this relay incorporating:
- a second make contact of said generator-to-motor change-over relay;
- a make contact of the gas-heater shut-down relay, which contact is connected in parallel with said make contact of the generator-to-motor changeover relay;
- a make contact of said relay for actuating the electric drive to close the third valve forming the eighth output of said gas-heating control unit;
- said relay for shutting down the gas heater, a feed circuit for a coil of this relay incorporating:
- a break contact of the relay for controlling the gas tem-perature at the outlet of the ignitor;
- a make contact of the time relay for switching off the ignitor, which contact is connected in series with said break contact of the relay for controlling the gas temperature at the outlet of the ignitor;
- a make contact of said second sensor responsive to furnace-gas temperature ahead of the gas turbine, which contact is closed as the gas temperature reaches its value at which the gas heater is shut down, this contact being connected in parallel with the two contacts, viz., said break contact of the relay for controlling the temperature of gas at the outlet of the ignitor and said make contact of the relay for switch-ing off the ignitor;
- a break contact of said second sensor responsive to the furnace gas temperature ahead of the gas turbine, which con-tact is closed as the gas temperature drops to its minimum value at which the gas heater is shut down, this contact being connected in parallel with said make contact of said second sensor responsive to temperature of furnace gas ahead of the gas turbine;
- a make contact of the relay operative upon completion of the gas-heater starting cycle, which is connected in series with said break contact of said second gas-temperature sensor;
- a make contact connected in parallel with said two con-tacts, viz., the break contact of said second temperature sensor and the make contact of said gas-heater starting cycle completion relay, this contact forming said seventh output of said shut-down control unit;
- a make contact of the relay for controlling the minimum gas flow rate, which is connected in parallel with said make contact of said second gas-temperature sensor;
- a make contact forming said sixth output of said shut-down control unit, which contact is connected in series with said make contact of the relay for controlling the minimum gas flow rate;
- a make contact of the relay for shutting down the gas heater, which contact is connected in parallel with said make contact of said second gas-temperature sensor;
- a break contact of said push-button switch for releasing the gas heater from protections being connected in series with said make contact of the relay for shutting down the gas heater;
- three make contacts of the gas-heater shut-down relay forming said sixth, seventh, and tenth outputs of said gas-heating control unit;
- a break contact forming said ninth output of said gas-heating control unit.

7. A control system as claimed in claim 6, wherein said changeover control unit comprises:
- a pressure-regulator changeover relay, a feed circuit for a coil of this relay incorporating:
- a make contact of said sensor responsive to the blast-furnace gas temperature ahead of the gas turbine, which con-tact is closed as the minimum gas temperature at which said pressure regulator can be switched over to the input of said rotor-speed regulating system is exceeded;
- a break contact of the gas-heater shut-down relay, which contact is connected in series with said make contact of said sensor responsive to furnace-gas temperature;
- a break contact connected in series with said break con-tact of the gas-heater shut-down relay, which contact forms said eighth output of said shut-down control unit;
- two make contacts of this pressure-regulator changeover relay forming the first and second outputs of said change-over control unit;
- a relay for reducing load of the gas turbine, a feed circuit for a coil of this relay incorporating:
- a make contact of the gas-heater shut-down relay;
- a break contact of the relay operative upon completion of the gas-heater starting cycle and connected in parallel with said gas-heater shut-down relay;
- a make contact of said sensor responsive to the flow rate of furnace gas, which contact is closed as the rate of gas flow through the gas turbine reaches its upper limit with the gas heater being inoperative, this contact being connected in series with said break contact of said relay operative upon completion of the gas heater starting cycle;
- a make contact of said relay for reducing load of the gas turbine forming said third output of said changeover control unit;
- a break contact of said relay for reducing load of the gas turbine forming said fourth output of said changeover control unit.

8. A control system as claimed in claim 7, wherein said shut-down control unit comprising:
- a push-button switch for releasing the installation from its protections;
- a push-button switch for the installation shut-down;
- a shut-down relay, a feed circuit for a coil of this relay incorporating:
- a make contact of said push-button switch for stopping the installation;
- a make contact of the relay operative for preparing the oil-pump starting, which is connected in parallel with said make contact of said push-button switch for stopping the installation;
- a make contact of an emergency shut-down relay, which contact is connected in series with said make contact of the relay operative for preparing the oil-pump starting;
- a make contact of said shut-down relay, which contact is connected in parallel with said make contact of said emergency shut-down relay;
- three break contacts of said shut-down relay forming, respectively, the first, fifth and eighth outputs of said shut-down control unit;
- three make contacts of this shut-down relay forming, respectively, said fourth, sixth, and tenth outputs of said shut-down control unit;
- a relay for disconnecting the electric generator for the power line, a feed circuit for a coil of this relay incor-porating:
- a make contact of the shut-down relay;
- a make contact of said sensor responsive to position of the closing diaphragm gate, which contact is closed upon its closure, this contact being connected in series with said make contact of the shut-down relay;
- two make contacts of this relay for disconnecting the electric generator from the power line forming said second and ninth outputs of said shut-down control unit;
- said emergency shut-down relay, a feed circuit for a coil of this relay incorporating:
- a make contact of said sensor responsive to rotational speed of the rotor, which contact is closed at the maximum rotor speed;
- a make contact of said sensor responsive to the blast-furnace gas temperature ahead of the gas turbine, which con-tact is connected in parallel with said make contact of said sensor responsive to the rotor speed;
- a make contact of the sensor responsive to the maximum temperature of bearings of the gas turbine and the electric generator, which contact is connected in parallel with said make contact of said sensor responsive to the rotor speed;
- a make contact of the sensor responsive to the maximum vibration of bearings of the gas turbine and the electric generator, which contact is connected in parallel with said make contact of said sensor responsive to the rotor speed;
- a make contact of said emergency shut-down relay, which contact is connected in parallel with said make contact of said sensor responsive to the rotor speed;
- a make contact of said sensor responsive to oil pressure in the oiling system, which contact is closed as the oil pressure drops to its lower permissible limit, this contact being connected in parallel with said make contact of said sensor responsive to the rotor speed;
- a break contact of said sensor responsive to position of said first valve, which contact is opened upon its opening, this contact being connected in series with said make con-tact of said sensor responsive to oil pressure in the oiling system;
- a break contact of said push-button switch for releasing the installation from protections thereof being connected in series with said make contact of said sensor responsive to the rotor speed;
- two make contacts of this emergency shut-down relay form-ing said third and seventh outputs of said shut-down control unit.

9. A control system as claimed in claim 8, wherein said filling and emptying control unit comprises:
- a switch for actuating the filling and emptying of the installation;
- a relay for actuating the respective electric drive of the first valve, a feed circuit for a coil thereof incorporating:
- a make contact of the shut-down relay, which forms said tenth output of said shut-down control unit;

- a make contact of this relay for actuating the electric drive of the first valve forming said second output of said filling and emptying control unit;
- a relay operative upon closure of said first valve, a feed circuit for a coil of this relay incorporating:
- a make contact of said sensor responsive to position of said first valve, which contact is closed upon closure thereof;
- a relay operative upon the opening of said second valve, a feed circuit for a coil of this relay incorporating:
- a make contact of said sensor responsive to position of said second valve, which contact is closed upon opening thereof;
- a relay operative upon closure of said fifth valve, a feed circuit for a coil of this relay incorporating:
- a make contact of said sensor responsive to position of said fifth valve, which contact is closed upon closure thereof;
- a relay for actuating the electric drive of said second valve, a feed circuit for a coil thereof incorporating:
- a make contact of said relay operative upon closure of the first valve;
- a first make contact of said push-button switch for actu-ating the filling and emptying of the installation, which contact is closed in the "emptying" position of the switch, this contact connected in series with said make contact of the relay operative upon closure of the first valve;
- a coil of a relay for actuating the respective electric drive to open said sixth valve;
- a make contact of said sensor responsive to position of said second valve, which contact is closed upon closure thereof, this contact being connected in series with said contact of said switch for actuating the filling and emptying of the installation;
- a make contact of said relay for opening said second valve connected in parallel with said contact of said sensor responsive to position of said second valve and with said first contact of said filling and emptying control switch;
- a third contact of said filling and emptying control switch, closing in the "filling" position and connected in series to said make contact of said relay responsive to open-ing of said second valve;
- a coil of a relay for actuating the respective electric drive to open said fifth valve, which coil is connected in series with said make contact of said sensor responsive to position of said sixth valve;
- a make contact of said sensor responsive to position of said sixth valve, which contact is closed upon closure thereof, this contact being connected in parallel with said make contact of said sensor responsive to position of said second valve and with said coil of the relay for actuating the electric drive to open said sixth valve;
- a make contact of the relay for actuating the electric drive to close said second valve forming said third output of said filling and emptying control unit;
- a make contact of the relay for actuating the respective electric drive to open said sixth valve forming said eighth output of said filling and emptying control unit;
- a make contact of the relay for actuating the respective electric drive to open said fifth valve forming said seventh output of said filling and emptying control unit;
- a time relay for emptying the installation, a feed cir-cuit for a coil of this relay incorporating:
- a make contact of said sensor responsive to position of said fifth valve, which contact is closed upon opening thereof;, - a relay for actuating the respective electric drives to close said fifth and sixth valves, a feed circuit for a coil thereof incorporating:
- a second contact of said switch for actuating the filling and emptying of the installation, which contact is closed in the neutral position of the switch;
- a make contact of the time relay for emptying the installa-tion, which contact is connected in series with said make contact of said switch for actuating the filling and emptying of the installation;
- a make contact of the relay for actuating the respective electric drive to open said second valve, which contact is connected in parallel with said make contact of said time relay for emptying the installation;
- make contacts of this relay for actuating the respective electric drives to close said fifth and sixth valves forming said fourth and fifth outputs of said filling and emptying control unit;
- a relay for actuating the respective electric drive to open said second valve, a feed circuit for a coil of this relay incorporating:
- a make contact of said relay operative upon closure of said fifth valve, which contact is connected in series with said make contact of said switch for filling and emptying the installation;
- a make contact of this relay for actuating the electric drive to open said second valve forming said sixth output of said filling and emptying control unit;
- said output relay, a feed circuit for a coil of this relay incorporating:
- a make contact of the relay operative upon closure of said first valve;
- a make contact of the relay operative upon the opening of said second valve, this contact being connected in series with said make contact of the relay operative upon closure of said first valve;
- a make contact of the relay operative upon closure of said fifth valve, which contact is connected in series with said make contact of the relay operative upon the opening of said second valve;
- a make contact of said sensor responsive to position of said sixth valve, which contact is closed upon closure there-of, this contact being connected in series with said make contact of the relay operative upon closure of said fifth valve;
- a make contact of this output relay forming said first output of said filling and emptying control unit.