Boiler and a boiler element with combustion under pressure

Claim 1

A STRUCTURAL ELEMENT FOR A BOILER WITH COMBUSTION UNDER PRESSURE COMPRISING, IN COMBINATION, A PRESSURERESISTANT VERTICAL CYLINDRICAL OUTER BODY HAVING A FIRST OPENING TRANSVERSELY OF ITS DIRECTION OF ELONGATION; AN INNER BODY FORMED BY CONTIGUOUS VAPORIZING TUBES AND A METAL CASING FIXED TO SAID TUBES, SAID METAL CASING AND SAID TUBES THEREBY FORMING A FLUID-TIGHT INNER BODY, SAID INNER BODY BEING LOCATED IN SAID OUTER BODY WITH THE COMPLETE OUTER SURFACE OF THE INNER BODY BEING SPACED FROM THE INNER SURFACE OF THE OUTER BODY, SAID INNER BODY BEING FORMED WITH A SECOND OPENING TRANSVERSELY OF ITS DIRECTION OF ELONGATION AND ALIGNED WITH SAID FIRST OPENING, SAID SURFACES DEFINING BETWEEN THEMSELVES A FREE SPACE FOR THE PASSAGE OF COMBUSTION AIR THERETHROUGH; A HEAT EXCHANGER STRUCTURE HAVING AN OPENING AND ARRANGED IN SAID INNER BODY AND EXTENDING IN SUBSTANTIALLY HORIZONTAL DIRECTION; AND A PLURALITY OF VERTICALLY SUPERPOSED RELEASABLY CONNECTED HEAT EXCHANGE ELEMENS LOCATED ALSO WITHIN SAID INNER BODY, SAID HEAT EXCHANGE ELEMENTS BEING SO DIMENSIONED AS TO BE EXTRACTABLE FIRST IN VERTICAL DIRECTION THROUGH SAID OPENING ON SAID HEAT EXCHANGER STRUCTURE AND THEN IN SUBSTANTIALLY HORIZONTAL DIRECTION THROUGH SAID FIRST AND SECOND OPENINGS, WHEREBY SERVICING AND REPAIR OF SAID HEAT EXCHANGE ELEMENTS ARE FACILITATED.