Plate heat exchanger

1. A plate heat exchanger comprising flow channels through which a first and a second flow flows in concurrent or countercurrent flow, which flow channels are formed for a first medium between individual plates ( 1 ) joined together to form pairs (P) of plates, respectively, and for a second medium between the pairs (P) of plates joined together to form a stack (S) of plates, wherein the individual plates ( 1 ) and the pairs (P) of plates are connected to each other at longitudinal edges ( 12 ) and contact surfaces ( 13 ) running parallel to a main flow direction, wherein the stack of plates comprises inflow and outflow cross-sections (Z 1 , Z 2 , A 1 , A 2 ), arranged diagonally and corresponding in a longitudinal direction, for the first medium and inflow and outflow cross-sections (Z 1 , Z 2 , A 1 , A 2 ), adjacent thereto in a transverse direction, for the second medium, wherein the inflow and outflow cross-sections (Z 1 , Z 2 , A 1 , A 2 ) for the first medium are in each case offset by half the height of the inflow and outflow cross-sections (Z 1 , Z 2 , A 1 , A 2 ) for the second medium, wherein the individual plate ( 1 ) is provided with a profiling ( 31 , 32 ) that generates turbulences, wherein

the profiling ( 31 , 32 ) is formed perpendicular to the main flow direction over the entire bottom ( 11 ) up to the contact surfaces ( 13 ), and

in a region of the contact surfaces ( 13 ), the individual plates ( 1 ) are shaped to form edge channels ( 15 ) that are arranged between the flow channels and the longitudinal edges ( 12 ), respectively, the edge channels delimited in a direction parallel to a stacking direction of the individual plates by opposed upper and lower boundary walls extending in the longitudinal direction, wherein the opposed upper and lower boundary walls of each edge channel each are shaped to provide the respective edge channel with at least two blocking embossments staggered relative to each other over a longitudinal extension of the edge channels,

wherein a first one of the blocking embossments is located on a first side of the edge channel facing the flow channels and extends into the interior of the edge channel in a direction toward the longitudinal edge, and

wherein a second one of the blocking embossments is located on a second side of the edge channel, opposite the first side and facing the longitudinal edge, and extends into the interior of the edge channel in a direction toward the first side of the edge channel,

wherein the blocking embossments each consist of a first embossment member and a second embossment member, wherein the first embossment member is provided by the upper boundary wall and the second embossment member is provided by the lower boundary wall,

wherein, viewed in a cross-sectional view, the blocking embossments each extend across the full height of the edge channel and over at least 50% of the width of the edge channel measured from the first side to the second side, wherein the blocking embossments each are shaped as a circle segment and a sagitta of the circle segment equals half of said width of the edge channel or is greater than half of said width of the edge channel, wherein the at least two staggered blocking embossments generate in the edge channels a cross-sectional area having a cross-sectional size that varies over said longitudinal extension, respectively.

2. The plate heat exchanger according to claim 1 , wherein the edge channels ( 15 ) are formed to be S-shaped or multiple times S-shaped.

3. The plate heat exchanger according to claim 1 , wherein the individual plates ( 1 ) within an inlet region (E) comprise guide blades ( 2 ) formed by stamped embossments protruding into the flow channel, wherein the guide blades ( 2 ) are formed in an arch shape with an inflow leg ( 21 ) aligned substantially parallel to the main flow direction and an outflow leg ( 22 ) aligned at an angle to the inflow leg ( 21 ), wherein the inflow legs ( 21 ) and the outflow legs ( 22 ) are arranged at an angle between 140° and 100° relative to each other.

4. The plate heat exchanger according to claim 3 , wherein the inflow legs ( 21 ) and the outflow legs ( 22 ) are arranged at an angle between 135° and 112° relative to each other.

5. The plate heat exchanger according to claim 3 , wherein the guide blades ( 2 ) of the inflow cross-sections (Z 1 , Z 2 ) do not protrude beyond a longitudinal center of the individual plates ( 1 ), wherein the inflow legs ( 21 ) and the outflow legs ( 22 ) have identical lengths, and wherein the guide blades ( 2 ) are arranged at the same distance from the associated transverse edge ( 14 a , 14 b ) of the respective individual plate ( 1 ).

6. The plate heat exchanger according to claim 3 , wherein the inlet region is divided relative to a longitudinal center of the individual plates into a first region and a second region, wherein the first and second regions each have a peripheral contour and the peripheral contours are mirror-symmetrical to each other relative to the longitudinal center of the individual plates and wherein the guide blades are arranged only in the first region and not in the second region, wherein the profiling ( 31 , 32 ) protrudes in the first region up to the guide blades ( 2 ) and the second region is free of the profiling.

7. The plate heat exchanger according to claim 3 , wherein the guide blades ( 2 ) are completely stamped through so that the guide blades ( 2 ) rest without any gap against the adjacent individual plate ( 1 ).

8. The plate heat exchanger according to claim 7 , wherein the guide blades ( 2 ) as spacers serve for supporting.

9. The plate heat exchanger according to claim 1 , wherein the profiling ( 31 , 32 ) has stamped knobs ( 31 , 32 ).

10. The plate heat exchanger according to claim 9 , wherein some of the stamped knobs ( 31 , 32 ) are formed as spacers for adjacent individual plates ( 1 ).