Safety control system for steam generators

Claim 1

A WET TUBE STEAM GENERATOR COMPRISING SOURCES OF FUEL AND WATER SUPPLY AND MEANS FOR REGULATING AIR FLOW THROUGH THE COMBUSTION CHAMBER, CONTROL MEANS FOR REGULATING SAID FUEL AND WATER SUPPLY, SAID CONTROL MEANS INCLUDING FURTHER MEANS MONITORING THE OPERATION OF THE GENERATOR AND PROVIDING A PRESSURE CONTROL SIGNAL; MEANS FOR TERMINATING OPERATION OF THE GENERATOR IN THE EVENT OF A TUBE RUPTURE, SAID MEANS COMPRISING A PLURALITY OF PRESSURE RESPONSIVE SWITCHES, ONE OF SAID SWITCHES BEING RESPONSIVE TO AIR PRESSURE IN THE COMBUSTION CHAMBER, THE SECOND OF SAID SWITCHES OPERATING IN RESPONSE TO VARIATIONS IN THE RATIO FEED WATER FLOW TO STEAM OUTPUT, THE THIRD SWITCH RESPONDING TO PRESSURE ON THE OUTPUT SIDE OF THE GENERATOR, SAID FIRST AND THIRD SWITCHES BEING CONNECTED IN SERIES AND SAID SECOND AND THIRD SWITCHES ALSO BEING CONNECTED IN SERIES, SAID SECOND-MENTIONED SWITCH BEING CONNECTED IN A PARALLEL CIRCUIT WITH RESPECT TO SAID FIRST-MENTIONED SWITCH, MEANS REGULATING FLOW FROM SAID WATER SOURCE TO AND THE RATE OF FUEL COMBUSTION IN SAID GENERATOR, SAID MEANS BEING OPERABLE TO A CLOSED POSITION WHEN EITHER SAID FIRST AND SAID THIRD-MENTIONED SWITCH OR SAID SECOND AND THIRD MENTIONED SWITCH IS CLOSED DUE TO ABNORMAL CONDITIONS SENSED IN THE GENERATOR WHEREBY TUBE RUPTURE THEREIN WILL RESULT IN CUT-OFF OF THE SUPPLY OF FUEL AND WATER TO THE GENERATOR.