Patent ID: 7600559

Claim:
A plate heat exchanger for exchanging heat between a first media and a second media, comprising: a plurality of first heat exchanger plates alternately stacked with a plurality of second heat exchanger plates between a base plate and a cover plate, said first and second heat exchanger plates having at least four passages therethrough which align to define a first collecting channel and a first distribution channel for the first media and a second collecting channel and a second distribution channel for the second media; first flow channels for the first media, each of said first flow channels being defined between one side of at least one of said first heat exchanger plates and a facing one side of the second heat exchanger plate adjacent said first plate one side, wherein said one side of said at least one first heat exchanger plate is substantially spaced apart from said facing one side of said second heat exchanger plate to form said first flow channels; and second flow channels for the second media, each of said second flow channels being defined between the other side of said at least one first heat exchanger plate and the other side of the second heat exchanger plate adjacent said at least one first plate other side, said second flow channels being defined by a plurality of discrete recesses defined within a thickness of at least one of the first and second heat exchanger plates, and said other sides being substantially metallically connected along their surfaces; wherein said first and second heat exchanger plates have a continuous bent edge at which adjacent heat exchanger plates are metallically connected to each other, the bent edges of said plurality of first heat exchanger plates are longer than the bent edge of said plurality of said second heat exchanger plates, and the bent edges of the second heat exchanger plates separate the second heat exchanger plates from adjacent first heat exchanger plates and thereby at least partially define the first flow channels.