Patent ID: 6397940
Filing Date: 2002-06-04
Classification: B21D,B23K,F28D,Y10T

Abstract:
A method of joining at least four heat transfer plates (2) to a plate package (3) for a plate heat exchanger (1), wherein each heat transfer plate (2) comprises an outer edge portion (10) extending around the heat transfer plate (2) in its edge area and an inner edge portion (11) extending around the heat transfer plate (2) inside the outer edge portion (10), and wherein the method includes the steps of: joining the heat transfer plates (2) in pairs at a first contact plane (17) to at least two plate pairs (16) along said inner edge portions (11),bringing an outer edge portion (10) of one of said plate pairs (16) to abutment at a second contact plane (20) to an outer edge portion (10) of another of said plate pairs (16), and welding said two outer edge portions (10) to each other by means of a weld joint (21), wherein said weld joint (21) is produced by means of a high energy beam directed towards one of said two outer edge portions (01) at a distance from the outer edge (9) thereof and at an angle (a) other than perpendicular with respect to said contact plane (20).