Deep combustion radiant surfaces with special slotting

Claim 1

A RADIANT GRID ELEMENT FOR A GAS BURNER COMPRISING A UNITARY BLOCK OF REFRACTORY MATERIAL DEFINING A MYRIAD OF MINUTE-BORE ELONGATED PASSAGES EXTENDING THERETHROUGH FROM A FIRST BOUNDARY SURFACAE OF SAID BLOCK TO A SECOND BOUNDARY SURFACE THEREOF, EACH SAID PASSAGE DEFINING A SEPARATE AND DISTINCT PATH FOR THE FLOW FROM SAID FIRST SURFACE OF A STREAM OF COMBUSTIBLE GAS MIXTURE TOWARD SAID SECOND SURFACE FOR COMBUSTION ADJACENT TO SAID SECOND SURFACE, SAID BLOCK AT SAID SECOND BOUNDARY SURFACE DEFINING THEREIN A PLURALITY OF SLOTS EACH HAVING GENERALLY OPPOSING SIDE WALLS WHICH OVER A MAJOR PORTION OF THE DEPTH OF SAID SLOTS ARE GENERALLY PARALLEL TO THE AXES OF SAID PASSAGES, SAID SIDE WALLS OF SAID SLOTS BEING SPACED APART A MINIMUM DISTANCE WHICH IS LESS THAN THE MAXIMUM CROSSSECTIONAL DIMENSION OF ANY SAID PATH-DEFINING PASSAGE, EACH SAID SLOT HAVING ITS SAID SIDE WALLS INTERSECTING AND JOINING AT LEAST TWO ADJACENT SAID PASSAGES, THE INTERSECTION OF THE BOTTOM-MOST PORTION OF SAID SLOT WITH ONE OF SAID SIDE WALLS OF SAID PASSAGES JOINED THEREBY DEFINING A SPACE OF SUBSTANTIALLY INCREASED CROSS-SECTIONAL AREA RELATIVE TO THAT OF ANY PASSAGE TO LOWER THE VELOCITY OF THE GAS MIXTURE IN SUCH SPACE AND THEREBY INDUCE COMBUSTION IN AND NEAR THE BOTTOM OF SAID SLOTS, THE SAID SLOT WALLS FORMING IN THE REGION BETWEEN THE PASSAGES JOINED BY SAID SLOTS A PAIR OF MUTUALLY OPPOSING RIBS WIHICH EXTEND DOWNWARDLY BELOW SAID SECOND BOUNDARY SURFACE TO THE LEVEL AT WHICH THE JOINED PASSAGE IS INTERSECTED BY THE BOTTOM OF THE ASSOCIATED SLOT, THE ARRANGEMENT OF SAID PASSAGES AND THEIR DIMENSIONS TOGETHER WITH THE DEPTH AND WIDTH OF SAID SLOTS COMPRISING MEANS WHICH IS JOINTLY OPERABLE TO CAUSE AT LEAST SOME OF THE GAS MIXTURE TO BURN AT SUBSTANTIALLY THE BOTTOM OF THE RESPECTIVE SLOTS, THE THICKNESS OF SAID BLOCK AT ITS MINIMUM WITHIN EACH SAID SLOT AND THE NATURE OF THE REFRACTORY MATERIAL OF SAID BLOCK COMPRISING MEANS WHICH IS JOINTLY OPERABLE TO PREVENT SAID FIRST SURFACE FROM REACHING THE IGNITION TEMPERATURE OF SAID GAS MIXTURE, AND EACH SAID PASSAGE BEING MANY TIMES LONGER THAN ITS MAXIMUM CROSS-SECTIONAL DIMENSION AND SUFFICIENTLY NARROW TO PREVENT THE FRAME FROM BACK-PROPAGATING THERETHROUGH TO SAID FIRST SURFACE.