Heat transfer apparatus for water heater

Claim 1

In a heat transfer apparatus for a water heating having a combustion chamber shell surrounding a gas burner, a plurality of parallel fin plates disposed at an open top end of the combustion chamber shell, and a water tube assembly comprising an inlet tube section, an outlet tube section, and a plurality of parallel tube sections connecting to said inlet and outlet tube sections; the improvement comprising: a plurality of circular openings being provided in rows on each said fin plate, and being aligned horizontally and evenly spaced apart from each other for supporting and positioning said parallel tube sections; an even number of said circular openings being provided in each said row thereof, which are spaced one row above another row; an equal number of turbulence fin arrays as that of said circular openings being provided in each said row on each said fin plate; said circular openings and said turbulence fin arrays being alternately arrayed horizontally and vertically; a plurality of vertically arrayed and evenly spaced fin slots being provided on each said turbulence fin array of any row, for guiding combustion gas to flow upwards therethrough from one side of said fin plate to another side thereof while said fin slots of each turbulence array of any adjacent row of said any row are formed so as to guide combustion gas to flow obliquely upwards therethrough from one side of said fin plate to an opposing side thereof; a plurality of flow-splitting bends and flow-merging bends being provided to interconnect half of said tube sections on the same row which are supported and positioned in said circular openings, and which are divided evenly into two parts.