Flue gas heat exchanger and fin therefor

Heat exchanger comprising:

• a plurality of fins, each having a first aperture and a second aperture that define an open area for receiving a first fluid;
• wherein said open area is substantially constant among said plurality of fins;
• an inner jacket contacting each of said plurality of fins;
• and
• an outer jacket surrounding said inner jacket defining a chamber for containing a second fluid therein;
• wherein said first aperture and said second aperture each define sectors of a circle extending from a central part to an outer periphery for conducting the first fluid toward said inner jacket;
• wherein said inner jacket is configured to transfer heat to the second fluid via said plurality of fins.

Heat exchanger comprising:

• a plurality of fins, each having open area for receiving a first fluid;
• an inner jacket contacting each of said plurality of fins along a heat transfer area substantially constant for each of said plurality of fins;
• and
• an outer jacket surrounding said inner jacket defining a chamber for containing a second fluid therein;
• wherein said open area defines a sector of a circle extending from a central part to an outer periphery for conducting the first fluid toward said inner jacket;
• wherein said inner jacket is configured to transfer heat to the second fluid via said plurality of fins.