Plate heat exchanger and method for producing same

Abstract

A plate heat exchanger comprises a stack of rectangular heat transfer plates, wherein each rectangular heat transfer plate comprises a circumference with four circumference edges arranged at the circumference of the rectangular heat transfer plate, a rectangular heat transfer wall extending between the circumference edges of the heat transfer plate, the rectangular heat transfer wall defining a plane and comprising a circumference portion extending to the circumference edge in the plane of the heat transfer wall, and the heat transfer plate further comprises at least two folded parts arranged at the circumference of the heat transfer plate and extending from the heat transfer wall over the circumference edge of the heat transfer plate, the folded parts contacting the heat transfer wall for forming spacer elements. Two opposite folded parts are folded towards a same side of the plane of the rectangular heat transfer wall, or at least two adjacent folded parts of the rectangular heat transfer wall are each folded towards opposite sides of the plane of the rectangular heat transfer wall with respect to the adjacent folded part. Pairs of heat transfer plates are arranged so that each folded part of one heat transfer plate is in contact over the entire length of the corresponding circumference edge either with a folded part of an adjacent heat transfer plate or with a circumference portion of the heat transfer wall of an adjacent heat transfer plate.

1 . Plate heat exchanger for gas-liquid heat exchange comprising a stack of rectangular heat transfer plates,
 wherein first and second flow channels are arranged alternately between the heat transfer plates of the stack, with every first flow channel for a through-flow of a first fluid and every second flow channel for a through-flow of a second fluid,   wherein each rectangular heat transfer plate comprises a circumference with four circumference edges arranged at the circumference of the rectangular heat transfer plate, a rectangular heat transfer wall extending between the circumference edges of the heat transfer plate, the rectangular heat transfer wall defining a plane and comprising a circumference portion extending to the circumference edge in the plane of the heat transfer wall, and the heat transfer plate further comprises at least two folded parts arranged at the circumference of the heat transfer plate and extending from the heat transfer wall over the circumference edge of the heat transfer plate, the folded parts contacting the heat transfer wall for forming spacer elements,   wherein two opposite folded parts are folded from the heat transfer wall towards a same side of the plane of the rectangular heat transfer wall, or at least two adjacent folded parts of the rectangular heat transfer wall are each folded from the heat transfer wall towards opposite sides of the plane of the rectangular heat transfer wall with respect to the adjacent folded part, and wherein pairs of heat transfer plates are arranged so that each folded part of one heat transfer plate is in contact either with a folded part of an adjacent heat transfer plate or with a circumference portion of the heat transfer wall of an adjacent heat transfer plate.   
     
     
         2 . Plate heat exchanger according to  claim 1 , wherein the circumference edges comprise two length side edges and two width side edges, wherein the plate heat exchanger comprises first inlet and outlet openings formed by corresponding pairs of heat transfer plates and arranged at the length side edge and second inlet and outlet openings formed by corresponding pairs of heat transfer plates and arranged at the width side edge, and wherein a length (W) of each second inlet and outlet opening at the width side edges is larger than a length (L) of each first inlet and outlet opening at the length side edges. 
     
     
         3 . Plate heat exchanger according to  claim 2 , wherein the length (W) of each second inlet and outlet opening is at least 2 times larger, particularly at least 2.5 times larger, very particularly at least 3 times larger than the length (L) of each first inlet and outlet opening. 
     
     
         4 . Plate heat exchanger according to  claim 2 , wherein the total number of folds of the folded parts separating the respective heat transfer walls on the width side edges and delimiting the first inlet and outlet openings is larger than the total number of folds of the folded parts separating the respective heat transfer walls on the length side edges and delimiting the second inlet and outlet openings. 
     
     
         5 . Plate heat exchanger according to  claim 1 , wherein the first flow channels are liquid flow channels extending from the first inlet openings to the first outlet openings and are connectable to a liquid inlet port and a liquid outlet port respectively and forming a liquid channel path, and the second flow channels are gas flow channels extending from the second inlet openings to the second outlet openings and are connectable to a gas inlet port and a gas outlet port and forming a gas channel path. 
     
     
         6 . Plate heat exchanger according to  claim 4 , wherein the liquid channel path is orthogonal to the gas channel path. 
     
     
         7 . Plate heat exchanger according to  claim 1 , wherein at least one folded part has two or more folds folded onto each other. 
     
     
         8 . Plate heat exchanger according to  claim 1 , wherein at least three folded parts of the rectangular heat transfer wall are each folded from the heat transfer wall, in an alternating sequence, towards opposite sides of the plane of the rectangular heat transfer wall so that adjacent pairs folded parts are folded towards opposite sides of the plane of the rectangular heat transfer wall. 
     
     
         9 . Plate heat exchanger according to  claim 1 , wherein the heat transfer plates are made of a metal sheet having a thickness t and having a shape adapted to form the heat transfer plate. 
     
     
         10 . Plate heat exchanger according to  claim 1 , wherein the folded parts have a thickness corresponding to the number of folds of the folded part times the thickness t of the metal sheet. 
     
     
         11 . Plate heat exchanger according to  claim 1 , wherein the heat transfer walls are separated by the folded parts by a distance corresponding to the number of folds of the respective folded parts separating the corresponding heat transfer walls times the thickness t of the metal sheet the heat transfer plate is made of. 
     
     
         12 . Plate heat exchanger according to  claim 1 , wherein the heat transfer walls comprise a three-dimensional structure such as corrugations, dimples or chevrons. 
     
     
         13 . Plate heat exchanger according to  claim 1 , wherein the heat transfer plates are stacked against each other and joined together by welding, brazing or fusion bonding at least on the width side of the heat transfer plates. 
     
     
         14 . Plate heat exchanger according to  claim 1 , wherein the plate heat exchanger comprises at least one end plate for sealing the plate heat exchanger. 
     
     
         15 . Plate heat exchanger according to  claim 1 , wherein the thickness of the metal sheet the heat transfer plate is made of is in the range of from 0.5 mm to 2 mm, particularly from 0.7 mm to 1.3 mm very in particular from 0.75 mm to 1.25 mm.