Extended fin heat exchanger panel

Claim 1

A heat exchange panel formed from two superimposed rectangular plates bonded together along their edges and having an inlet and an outlet for circulating the heat exchange medium; a. one of said plates being corrugated to form groups of easily cleanable, smoothly rounded open-looped undulating fins having a reduced tendency to become fouled and intervening flat portions; b. the other one of said plates being substantially flat and sealed to the flat portions of said corrugated plate forming together therewith sealed strips separating said groups of open-looped undulating fins and sealed strips extending alternately from one bonded edge to a distance spaced from the opposite bonded edge to form open unsealed portions permitting the heat exchange medium to pass in heat exchange relationship successively through said groups of open-looped undulating fins in alternately reversed directions across the panel from the inlet to the outlet thereof; c. said substantially flat plate having a depressed portion extending between each of said strips and being co-extensive in length with each of said groups of undulations and spaced from the undulations facing said depressed portions to provide direct prime heat exchange between the open-looped fins of each of said groups and expose virtually the entire inner heat exchange surface of the panel to such direct prime heat exchange contact with the medium therein and provide a panel having a heat capacity coefficient K of approximately 2.5 BTU per square foot of projected surface times the difference in temperature between the panel and the ambient air.