Patent ID: 7174954

Claim:
A heat exchanger comprising: a plurality of parallel-oriented plates securely fixed between two outer walls to define between adjacent plates an area of sealed interleaved passages for two heat exchanging media, a plurality of channel means for conducting a hot medium and a cold medium such that a flow of hot and cold media takes place in an in-line and counter-flow fashion, each of said channel means being defined by directional baffle means and an internal return bend means located between said adjacent plates, said internal return bend means being removably configured to allow direct access to said channel means at at least one end; an external return bend means providing a transfer of the respective medium from one of said channel means to another of said channel means, said external return bend means being configured to provide a greater flow turbulence of the medium passing through each of said channel means, said external return bend means being incorporated into and extending outwardly from said outer walls; said outer walls and said plates are permanently fixed to provide a liquid-tight enclosure; two access doors configured to be removably engaged in an air and liquid tight fashion to allow accessibility simultaneously from said at least one end, said doors being of substantially flat configuration; wherein said external return bend means are adjacent to said doors; and wherein each of said directional baffle means is provided with rounded off ends having a diameter greater than the thickness of said directional baffle means in order to avoid snagging stringy material contained in said medium.