Patent ID: 6109254
Filing Date: 2000-08-29
Classification: F24H,F28D,F28F

Abstract:
In a heating apparatus including a burner for producing hot combustion gas and a clamshell heat exchanger receiving combustion gas from said burner for rejecting heat from the combustion gas to air flowing through the furnace, said heat exchanger defining a multi-pass flow passage for the combustion gas; the improvement wherein said heat exchanger comprises:a first plate member having a first series of parallel ridges and valleys, at least one of the valleys being deeper than other of the valleys,a second plate member facing the first plate member, the second plate member having a second series of ridges and valleys that are parallel to the first series of ridges and valleys, at least one of the valleys of the second series being deeper than other of the valleys of the second series;a first pass of said multi-pass flow passage defined by a number N1 of said ridges and valleys of said first and second series; anda second pass of said multi-pass flow passage defined by a number N2 of said ridges and valleys of said first and second series, said at least one deeper valley of the first series cooperating with said at least one deeper valley of the second series to separate the second pass from said first pass.