Welded plate heat exchanger and method for welding heat transfer plates to a plate heat exchanger

摘要

The present invention refers to a plate heat exchanger (1) for heat transfer between two fluids, comprising at least a permanently joined module (2) with several, principally rectangular heat transfer plates (3) equally distributed on each side of an imaginary centre plane (M) of the module, which is parallel to the plane of the heat transfer plates (3), the heat transfer plates (3) having inlet and outlet openings (13, 14) for respective fluids in their corner portions (15) and a heat transfer portion (16) located between respective inlet and outlet openings, in which an intermediate heat transfer plate (3B) has a weld (17A) against a first adjacent heat transfer plate (3A), extending at least round said heat transfer portion and round the inlet and outlet openings for one of the fluids and a weld (17B) against a second adjacent heat transfer plate (3C), extending at least round said heat transfer portion and round the inlet and outlet openings for the second fluid. At least one of said welds (17A, 17B) in at least an adjacent pair of heat transfer plates on each side of said centre plane is done in direction towards said centre plane.