Clamshell heat exchanger for a furnace or unit heater

摘要

A clamshell heat exchanger (10) is provided for use in a heating apparatus including a burner for producing hot combustion gas. The heat exchanger (10) defines a multi-pass flow passage (11) for the combustion gas and includes a first plate member (30) and a second plate member (32). The first plate member (30) has a first series of parallel ridges (36) and valleys (38a-b), with at least one of the valleys (38a) being deeper than other of the valleys (38b). The second plate member (32) faces the first plate member (30) and includes a second series of ridges (36) and valleys (38a-b) that are parallel to the first series of ridges (36) and valleys (38a-b), with at least one of the valleys (38a) of the second series being deeper than other of the valleys (38b) of the second series. A first pass (14, 16) of the multi-pass flow passage (11) is defined by a number N1 of the ridges (36) and valleys (38a-b) of the first and second series. A second pass (16, 18) of the multi-pass flow passage (11) is defined by a number N2 of the ridges (36) and valleys (38a-b) of the first and second series. The at least one deeper valley (38a) of the first series cooperates with the at least one deeper valley (38a) of the second series to separate the second pass (16, 18) from the first pass (14, 16). <IMAGE>