Tubular heater

Claim 1

THE COMBINATION OF BURNERS AND TUBE BANKS IN A FIRED HEATER ENCLOSURE HAVING FOUR SIDE WALLS FOR CONTROLLED HEATING OF PROCESS STREAMS COMPRISING: (A) A PAIR OF SPACED HORIZONTAL TUBE BANKS, EACH OF SAID BANKS HAVING AN INNER AND OUTER SIDE AND POSITIONED IN THE ENCLOSURE PARALLEL TO TWO OF THE SIDE WALLS WHEREIN SAID OUTER SIDES OF EACH OF SAID PAIR OF TUBE BANKS FACE ONE OF EACH OF THE PARALLEL SIDE WALLS: (B) SAID TUBE BANKS THEREBY FORMING THREE COMBUSTION CHAMBERS IN THE ENCLOSURE WHEREIN ONE OF SAID CHAMBERS IS ADJACENT ONE OF THE PARALLEL SIDE WALLS AND THE SECOND OF SAID CHAMBERS IS ADJACENT THE OTHER OF THE PARALLEL SIDE WALLS AND THE THIRD OF SAID THREE CHAMBERS IS INTERMEDIATE SAID FIRST AND SECOND CHAMBERS; (C) A PLURALITY OF SHORT FLAME RADIENT TYPE BURNERS SECURED TO BOTH OF THE PARALLEL SIDE WALLS FOR HEATING SAID FIRST AND SECOND CHAMBERS, RESPECTIVELY, AND FOR HEATING SAID OUTER SIDES OF EACH OF SAID PAIR OF PARALLEL TUBE BANKS FACING THE PARALLEL SIDE WALLS, RESPECTIVELY; AND (D) A PLURALITY OF LONG FLAME BURNEERS MOUNTED WITH THE OTHER TWO OF THE FOUR SIDE WALLS OF THE ENCLOSURE AT SPACED INTERVALS, SAID LONG FLAME BURNERS BEING POSITIONED ADJACENT SAID INTERMEDIATE THIRD CHAMBER TO ENABLE SAID BURNERS TO THEREBY UNIFORMLY HEAT SAID THIRD CHAMBER AND SAID INNER SIDE OF EACH OF SAID TUBE BANKS WHICH THEREBY ENABLES SUBSTANTIALLY UNIFORM HEATING OF SAID INNER AND OUTER SIDES OF EACH OF SAID TUBE BANKS WHICH FACILITATES SUBSTANTIAL UNIFORMITY OF HEATING THROUGHOUT SAID THREE CHAMBERS OF THE FIRED HEATER ENCLOSURE.