Furnace tube arrangement

Claim 1

A TUBE ARRANGEMENT FOR A TUBE HEATER COMPRISING, IN OPERABLE COMBINATION, A PAIR OF LIKE AND PARELLEL TUBE ARRANGEMENTS, EACH TUBE ARRANGEMENT COMPRISING A PLURALITY OF BANKS OF HORIZONTALLY POSITIONED PARALLEL TUBES, SAID PLURALITY COMPRISING AT LEAST FIRST, SECOND AND THIRD BANKS OF TUBES ARRANGED SERIALLY AND IN A VERTICAL PLANE, A FIRST HEADER COMMUNICATING WITH THE ENDS OF THE TUBES OF SAID FIRST BANK AT ONE END THEREOF, A SECOND HEADER COMMUNICATING THE ENDS OF SAID SECOND BANK OF TUBES CORRESPONDING TO SAID ONE END OF SAID FIRST BANK OF TUBES, A FIRST CONNECTING TUBE CONNECTING ADJACENT ENDS OF SAID FIRST AND SECOND HEADERS, A THIRD HEADER CONNECTING THE ENDS OF THE TUBES OF SAID SECOND BANK OPPOSITE SAID SECOND HEADER, A FOURTH HEADER CONNECTING THE TUBE ENDS OF SAID THIRD BANK OF TUBES ADJACENT SAID THIRD HEADER, A SECOND CONNECTING TUBE CONNECTING ADJACENT ENDS OF SAID THIRD AND FOURTH HEADERS, A FIFTH HEADER CONNECTING THE TUBE ENDS OF SAID THIRD BANK TUBES OPPOSITE SAID FOURTH HEADER, AN OUTLET TUBE CONNECTED WITH THE END OF SAID FIFTH HEADER OPPOSITE SAID SECOND HEADER FOR PASSAGE OF HEATED MATERIAL FROM SAID TUBE ARRANGEMENT, A FIRST BY-PASS TUBE COMMUNICATING THE FIRST CONNECTING TUBE OF ONE TUBE ARRANGEMENT WITH THE CORRESPONDING CONNECTING TUBE OF THE OTHER TUBE ARRANGEMENT, A SECOND BY-PASS TUBE COMMUNICATING THE SECOND CONNECTING TUBE OF ONE TUBE ARRANGEMENT WITH THE CORRESPONDING CONNECTING TUBE OF THE OTHER TUBE ARRANGEMENT, EACH FIRST BANK OF TUBES HAVING AN INLET HEADER COMMUNICATING WITH THE TUBE ENDS THEREOF ADJACENT SAID THIRD HEADER, A THIRD BY-PASS TUBE ENDS THEREOF ADJACENT SAID THIRD HEADER, EACH OTHER, ONE OF SAID TUBE ARRANGEMENTS BEING POSITIONED AT AN ELEVATION ABOVE THE OTHER TUBE ARRANGEMENT ABOUT HALF THE VERTICAL DISTANCE BETWEEN CENTERS OF ADJACENT TUBES IN SUCH A MANNER THAT ALL TUBES OF BOTH TUBE ARRANGEMENTS ARE EXPOSED FOR RADIANT HEATING.