Integral tank shell heat-exchange coils

Claim 1

A FABRICATED VESSEL COMPRISING PLURAL WALL PLATE SECTIONS SECURED TOGETHER AND INCLUDING AT LEAST ONE HEATEXCHANGE PLATE SECTION, THE HEAT-EXCHANGE PLATE SECTION COMPRISING A ONE-PIECE EXTRUSION HAVING PERIPHERIAL WEB PORTIONS, OF THICKNESS APPROXIMATING THE THICKNESS OF THE OTHER WALL PLATES, SAID PERIPHERAL WEB PORTIONS BORDERING UPON HEAT-EXCHANGE PORTIONS WHEREIN THE OVERALL THICKNESS OF THE EXTRUSION IS MORE THAN TWICE THE THICKNESS OF THE PERIPHERIAL PORTIONS AND EACH HEAT-EXCHANGE PORTION HAVING A MULTIPLICITY OF ADJACENT PARALLEL DUCTS EXTENDING THERETHROUGH AND SEPARATING THE THICKER PORTION OF THE EXTRUSION INTO INNER AND OUTER WALLS, THE SAID HEAT-EXCHANGER PORTIONS BETWEEN THE DUCTS COMPRISING CURVED FILETED RIBS INTEGRALLY JOINING THE INNER AND OUTER WALLS, AND EACH HEAT-EXCHANGE PORTION HAVING AN OPENING IN AN OUTER WALL TO EXPOSE OPEN ENDS OF AT LEAST ONE OF ITS DUCTS; A MANIFOLD PLATE SECURED TO THE HEAT-EXCHANGE PORTION AT THE OPENING AND CLOSING THE EXPOSED DUCT ENDS AND HAVING INLET AND OUTLET MEANS COMMUNICATING RESPECTIVELY WITH DIFFERENT DUCTS ENDS, AND SAID MANIFOLD PLATE HAVING VESSEL DRAINAGE PIPE MEANS EXTENDING THROUGH IT BETWEEN THE INLET AND OUTLET MEANS AND PASSING THROUGH THE INNER WALL OF THE HEAT-EXCHANGE SECTION; AND MEANS FOR CLOSING THE DUCTS AT THE END OF THE EXTRUSION AND FOR TRANSVERSELY JOINING SOME OF THE DUCTS TO FORM A CONTINUOUS TORTUOUS PATH THERETHROUGH BETWEEN SAID INLET AND OUTLET MEANS.