Steam generating unit

Claim 1

A STEAM GENERATING UNIT, COMPRISING (A) FRONT, REAR, SIDE, ROOF, AND FLOOR WALLS DEFINING A VERTICALLY-ELONGATED COMBUSTION CHAMBER, THE FRONT WALL HAVING A DOWNWARDLY-DIRECTED SURFACE FACING AND NEAR THE FLOOR WALL, (B) A CONVECTION PASS CONNECTED TO THE UPPER END OF THE REAR WALL OF THE COMBUSTION CHAMBER, (C) A RADIANT SUPERHEATER MOUNTED IN THE UPPER PART OF THE COMBUSTION CHAMBER ADJACENT THE FRONT WALL, (D) A CONVECTION SUPERHEATER MOUNTED IN THE CONVECTION PASS, (E) A DIRECTIONAL-FLAME BURNER LOCATED ON THE SAID DOWNWARDLY-DIRECTED SURFACE OF THE FRONT WALL, (F) A GAS RECIRCULATION MEANS INCLUDING AN INLET LOCATED ON THE REAR WALL ADJACENT THE FLOOR WALL IN OPPOSITION OF THE BURNER, THE INLET EXTENDING SUBSTANTIALLY ENTIRELY ACROSS THE WALL, (G) ADJUSTABLE VANES MOUNTED IN THE INLET TO REGULATE THE DIRECTION RELATIVE TO A HORIZONTAL PLANE OF FLOW OF RECIRCULATED GAS INTO THE COMBUSTION CHAMBER, (H) A DAMPER DISPOSED IN SAID GAS RECIRCULATION MEANS FOR REGULATING THE QUANTITY OF RECIRCULATED GAS WHICH IS INTRODUCED THROUGH THE INLET INTO THE COMBUSTION CHAMBER, (I) MEANS MEASURING THE TEMPERATURE OF SUPERHEATED STEAM AND OF LOAD, (J) A MAIN CONTROL RECEIVING SIGNALS FROM SAID MEANS, THE SIGNALS BEING INDICATIVE TO SUPERHEATED STEAM TEMPERATURE AND OF LOAD, AND (K) MEANS CONNECTED TO THE MAIN CONTROL AND OPERATIVE TO REGULATE THE SAID DIRECTIONAL-FLAME BURNER, THE SAID ADJUSTABLE VANES, AND THE SAID DAMPER TO MAINTAIN THE TEMPERATURE AT A PREDETERMINED VALUE THROUGHOUT A BROAD RANGE OF LOAD IN RESPONSE TO THE SAID SIGNALS.