Heat exchanger construction

Claim 1

HEAT EXCHANGER CONSTRUCTION INCLUDING A HEAT EXCHANGER SHELL FORMING A SHELL CHAMBER AND HAVING FLUID INLET MEANS AND FLUID OUTLET MEANS COMMUNICATING WITH SAID SHELL CHAMBER, TUBE SHEET MEANS CONNECTED TO THE SHELL, A TUBE BUNDLE CONNECTED TO THE TUBE SHEET MEANS AND EXTENDING GENERALLY LONGITUDINALLY WITHIN THE SHELL CHAMBER, THE TUBE BUNDLE HAVING A SERIES OF SUBSTANTIALLY UNIFORMLY SPACED TUBES, THE TUBES EXTENDING FROM THE TUBE SHEET MEANS SUBSTANTIALLY UNIFORMLY SPACED GENERALLY LONGITUDINALLY IN A FIRST BANK OF TUBE SECTIONS AND THEN SUBSTANTIALLY UNIFORMLY SPACED IN INVOLUTE PATHS LATERALLY AND THEN SUBSTANTIALLY UNIFORMLY SPACED IN COMBINED INVOLUTE LATERAL AND SERPENTINE PATHS FORMING AT LEAST A SUBSTANTIAL PART OF A SECOND BANK OF TUBE SECTIONS EXTENDING GENERALLY LONGITUDINALLY BACK TO THE TUBE SHEET MEANS, THE INVOLUTE LATERAL AND SERPENTINE PART OF THE SECOND BANK OF TUBE SECTIONS EXTENDING PROGRESSIVELY GENERALLY LATERALLY IN ONE GENERAL DIRECTION IN INVOLUTE PATHS AND THEN GENERALLY LONGITUDINALLY AND THEN GENERALLY LATERALLY IN INVOLUTE PATHS IN A DIRECTION GENERALLY OPPOSITE FROM SAID ONE DIRECTION WHILE THE TUBES IN SAID SECOND BANK REMAIN SUBSTANTIALLY UNIFORMLY SPACED THROUGHOUT SAID SECOND BANK, AND ALL OF THE PORTIONS OF THE TUBE SECTIONS IN AT LEAST THE SECOND BANK WHICH EXTEND LONGITUDINALLY BEING POSITIONED IN LATERALLY INVOLUTE ROWS.