Patent ID: 6230794
Filing Date: 2001-05-15
Classification: B21D,F28D,Y10T

Abstract:
A method of producing heat transfer plates (2), which are of the same size and have central heat transfer portions (15) of the same shape, each of the heat transfer plates (2) having through holes, so called port holes (8, 9; 14; 21; 27; 29), on respective sides of its heat transfer portion (15) for through flow of at least one heat exchange fluid and one passage portion (16; 22; 28; 30, 31, 32) which, when the heat transfer plate (2) abuts against another heat transfer plate in a plate heat exchanger, is adapted to delimit a distribution passage (17; 26) for through flow of said heat exchange fluid and which extends from one (14; 21; 27; 29) of said port holes to an area in or near said heat transfer portion (15), which area has the same position in relation to the heat transfer portion (15) in each of the heat transfer plates (2), separate operations being carried out for pressing the passage portions (16; 22; 28; 30, 31, 32) of said heat transfer plates (2) and for punching the holes which shall form said port holes (8, 9; 14; 21; 27; 29), respectively, comprising providing by said punching operation each one of separate or interconnected sheet metal pieces, which are to form the said heat transfer plates (2), with holes in a way such that said one port hole (14; 21; 27; 29) in a first sheet metal piece becomes of a different kind than the corresponding one port hole (14; 21; 27; 29) in a second sheet metal piece, the said one port holes (14; 21; 27; 29) of the sheet metal pieces being shaped by the punching operation such that they result in finished heat transfer plates (2) having differently sized passage portions (16; 22; 28; 30, 31, 32).