Heat exchanger closure bar construction

Abstract

In a heat exchanger of the plate-fin type through which two fluid streams of different temperatures are passed through alternate layers in a cross-flow arrangement whereby heat transfer occurs between the two fluid streams, solid closure bars attached to the heat exchanger core are shaped and arranged in a manner such that the closure bars form a continuous protruding flange at the corners or along the length of the heat exchanger core. The headers, which previously were welded directly to the heat exchanger core, are now welded to the flange, thereby preventing damage to the brazed heat exchanger core components and adding flexibility between core and headers during thermal cycling. In a preferred embodiment the closure bars on one face of the heat exchanger have an 'L' shape with the 'L' extending away from the core, and the closure bars on the adjacent face are straight and extend beyond the edge of the core the same distance as the extended 'L' and in the same plane to form a straight flange.