摘要 |
<p>A plate heat exchanger comprises a stack of heat transfer plates each extending in a general plane and provided with a main heat transfer portion with a corrugation pattern. Each heat transfer plate comprises an outer peripheral portion extending outside the main heat transfer portion and along a periphery. The outer peripheral portion comprises outer and inner edge portions. In the stack the heat transfer plates in their outer peripheral portions abut against each other alternately along the outer and inner edge portions, and are welded together alternately along the outer and inner edge portions. The heat transfer plates in the stack are welded together by melting material of the heat transfer plates closest to abutting faces of the edge portions by supplying welding energy in a direction substantially parallel to the general plane to produce weld joints between the heat transfer plates in the outer and inner edge portions.</p> |