Patent ID: 6935416

Claim:
A heat exchanger comprising: first heat transfer plates ( 41 ) having a plurality of first ridges ( 45 ) formed on one side and second heat transfer plates ( 42 ) having a plurality of second ridges ( 48 ) formed on one side, the first heat transfer plates ( 41 ) and the second heat transfer plates ( 42 ) being alternately superimposed; low pressure fluid passages ( 62 ) formed and partitioned by the plurality of first ridges ( 45 ) between said one side of the first heat transfer plates ( 41 ) and the other side of the second heat transfer plates ( 42 ), the low pressure fluid passages ( 62 ) extending in the longitudinal direction of the first and second heat transfer plates ( 41 , 42 ); and high pressure fluid passages ( 63 ) formed and partitioned by the plurality of second ridges ( 48 ) between said one side of the second heat transfer plates ( 42 ) and the other side of the first heat transfer plates ( 41 ), the high pressure fluid passages ( 63 ) having main fluid passages ( 64 ) defined by main ridges ( 49 ) extending in the longitudinal direction of the first and second heat transfer plates ( 41 , 42 ), and inlet fluid passages ( 65 a , 65 b ) defined by inlet ridges ( 50 a , 50 b , 50 c ) extending in a direction perpendicular to the longitudinal direction of the first and second heat transfer plates ( 41 , 42 ); wherein a plurality of the inlet ridges ( 50 a , 50 b , 50 c ) are formed at different intervals, and gaps (α, β) are formed between the downstream ends of the inlet ridges ( 50 a , 50 b , 50 c ) and upstream ends of the main ridges ( 49 ) and wherein the upstream ends of the main ridges ( 49 ) are positioned irregularly offset with respect to each other in the longitudinal direction of the plates ( 41 , 24 ).