Burner for tempered flame operation

Claim 1

A BURNER FOR TEMPERED FLAME OPERATION COMPRISING A BURNER BODY HAVING TWO COMMUNICATING COAXIAL COMBUSTION ZONES DISPOSED FOR THE PASSAGE OF FUEL SUCCESSIVELY THERETHROUGH, A FIRST ZONE OF RELATIVELY SMALL TRANSVERSE DIMENSION AND A SECOND ZONE OF RELATIVELY GREAT TRANSVERSE DIMENSION, SAID FIRST ZONE HAVING AN OUTLET OPENING ADJOINING AN INLET OPENING OF SAID SECOND ZONE, GENERALLY AXIALLY DIRECTED FUEL INLET MEANS DISPOSED IN AN INLET OPENING OF SAID FIRST ZONE AND ADMITTING FUEL INTO THE FIRST ZONE IN A DIRECTION TO PASS THROUGH THE FIRST ZONE INTO THE SECOND ZONE, FIRST AIR INLET MEANS ADMITTING AIR INTO THE FIRST ZONE ADJACENT SAID INLET MEANS, SECOND AIR INLET MEANS ADMITTING AIR INTO THE SECOND ZONE ADJACENT SAID FIRST ZONE WHERE THE SECOND ZONE COMMUNICATES WITH THE FIRST ZONE, AND THIRD AIR INLET MEANS ADMITTING AIR INTO THE SECOND ZONE AT A LOCATION THEREIN REMOTE FROM SAID FIRST ZONE, WHEREBY THE TURN-DOWN RATIO OF SAID BURNER IS GREATLY INCREASED, THE OPERATION OF SAID BURNER BEING THAT AS THE FUEL IS TURNED DOWN THE FLAME GENERATED BY COMBUSTION THEREOF PROVGRESSIVELY RECEDES FROM SAID SECOND ZONE INTO SAID FIRST ZONE.