Plate heat exchanger and method for manufacturing a plate heat exchanger

Abstract

The invention relates to a plate heat exchanger, which comprises a plate pack formed by corrugated heat exchange plates with openings for the flow of a first and a second heat exchange medium. The outer shell of the plate heat exchanger ( 1 ) has been formed by arranging separate strips ( 9, 9 ′) in the outer edge of the plate pack ( 2 ) so that the outer surfaces of the strips ( 9, 9 ′) are substantially in the same plane with the outer edges of the heat exchange plates ( 6, 6 ′), and by welding the strips ( 9, 9 ′) and the outer edges of the heat exchange plates ( 6, 6 ′) to each other.

1 - 14 . (canceled) 
     
     
         15 . A plate heat exchanger, which comprises
 a plate pack formed by arranging corrugated heat exchange plates one upon the other, where each heat exchange plate has openings,   flow channels inside the plate pack for at least a first and a second heat exchange medium formed by means of the openings of the heat exchange plates and which openings have been attached to each other at their outer perimeters so that through every second plate space of the plate pack is passed a flow of the first heat exchange medium and through every second plate space is passed a flow of the second heat exchange medium,   inlet and outlet connections for the first and second heat exchange medium, which have been arranged in connection with the flow channels,   
       wherein an outer shell of the plate heat exchanger has been formed by arranging separate strips in the outer edge of the plate pack so that
 the strips are between the pairs of heat exchange plates, in which pairs the outer edges of adjacent heat exchange plates are arranged against each other, and 
 the outer surfaces of the strips are substantially in the same plane with the outer edges of the heat exchange plates, 
 
       and by welding the strips and the outer edges of the heat exchange plates to each other, 
       and in that at least part of the contact surfaces of two or more uppermost and lowest heat exchange plates of the plate pack have been welded to each other or the heat exchanger comprises end plates, which have been arranged under and over the plate pack in connection with the uppermost and the lowest heat exchange plate. 
     
     
         16 . The plate heat exchanger according to  claim 15 , wherein the outer edge of the plate pair and two strips arranged on both sides of the plate pair have been welded by one welded seam. 
     
     
         17 . The plate heat exchanger according to  claim 15 , wherein the strip comprises at least one chamfered edge. 
     
     
         18 . The plate heat exchanger according to  claim 15 , wherein the width of the strip in the direction of the heat exchange plate is 3 to 20 mm. 
     
     
         19 . The plate heat exchanger according to  claim 15 , wherein the thickness of the heat exchange plate is 0.5 to 1.5 mm. 
     
     
         20 . The plate heat exchanger according to  claim 15 , wherein the heat exchange plates comprise corrugations which form a fish bone structure in the plate. 
     
     
         21 . The plate heat exchanger according to  claim 15 , wherein the structure of the heat exchanger is completely welded to form a compact element. 
     
     
         22 . The plate heat exchanger according to  claim 15 , wherein the plate pack has been constructed of rectangular heat exchange plates. 
     
     
         23 . Method for manufacturing a plate heat exchanger, the method comprising at least the following steps:
 arranging corrugated heat exchange plates one upon the other as a plate pack, where each heat exchange plate has openings and which openings form flow channels inside the plate pack for at least a first and a second heat exchange medium,   attaching the heat exchange plates in connection to each other at the outer perimeters of the openings so that through every second plate space of the plate pack is passed a flow of the first heat exchange medium and through every second plate space is passed a flow of the second heat exchange medium,   arranging inlet and outlet connections for the first and the second heat exchange medium in connection with the flow channels,   arranging separate strips between the pairs of heat exchange plates, in which pairs the outer edges of adjacent heat exchange plates are arranged against each other, so that the outer surfaces of the strips are substantially in a same plane with the outer edges of the heat exchange plates, and   welding the strips and the outer edges of the heat exchange plates to each other, and   welding least part of the contact surfaces of two or more uppermost and lowest heat exchange plates of the plate pack to each other or arranging the end plates under and over the plate pack in connection with the uppermost and the lowest heat exchange plate.   
     
     
         24 . The method according to  claim 23 , wherein the outer edge of the plate pair and the two strips arranged on both sides of the plate pair are welded by one welded seam.