Method for manufacturing a heat exchanger

Abstract

The method for manufacturing a heat exchanger from a plastic material comprises feeding of at least two sheet elements, and, by means of shaping means, shaping of said sheet elements to form heat exchanger plates. The shaping means are adapted to also undertake joining the sheet elements partly along edges so that a fluid inlet and outlet are created, whereby the sheet elements are pressed together. The heat exchanger plates are stacked and joined to a heat exchanger. The stack of heat exchanger plates is welded so that the fluid inlets are fluid outlets of the respective heat exchanger plates are combined to form a common fluid inlet and a common fluid outlet, and the sides of the heat exchanger plates are welded together, so that a fully functional heat exchanger is manufactured with plastic sheets as the only raw material.

1 . A method for manufacturing a heat exchanger from a plastic material, said method comprising the steps of:
 feeding at least two sheet elements made from said plastic material,   by means of shaping means, shaping of said sheet elements to form a number of heat exchanger plates, whereby said shaping means are adapted to also undertake joining the sheet elements partly along edges so that a fluid inlet and a fluid outlet are created, whereby the sheet elements are pressed together, and   two or more heat exchanger plates are stacked on top of one another, characterized by that the stacked heat exchanger plates are joined in order to assemble them into a heat exchanger, whereby the stack of heat exchanger plates is welded so that the fluid inlets and fluid outlets of the respective heat exchanger plates are combined to form a common fluid inlet and a common fluid outlet, and whereby the sides of the heat exchanger plates are welded together, so that a fully functional heat exchanger is manufactured with plastic sheets as the only raw material.   
     
     
         2 . A method for manufacturing a heat exchanger according to  claim 1 , whereby, during shaping of said sheet elements, a predetermined configuration is shaped by the sheets being placed in a mould, a vacuum being created between the mould and the individual sheets to establish a firm contact between the mould and the sheets, and subsequently pressure is applied against the surfaces of the sheets opposite the mould, whereby the predetermined configuration is shaped on the sheets. 
     
     
         3 . A method for manufacturing a heat exchanger according to  claim 1 , whereby, during shaping of said sheet elements, two sheet elements are positioned between two opposed vacuum forming moulds, and whereby the vacuum forming moulds are pressed against each other, whereby the two sheet elements are vacuum formed simultaneously and at the same time joined together at least along part of the edges of the heat exchanger plate being formed, as a result of the sheet elements being pressed together by the vacuum forming moulds. 
     
     
         4 . A method for manufacturing a heat exchanger according to  claim 3 , whereby the two sheet elements are furthermore joined together between longitudinal channels being formed in the heat exchanger plate being formed, as a result of the sheet elements being pressed together by the vacuum forming moulds. 
     
     
         5 . A method for manufacturing a heat exchanger according  claim 1 , whereby, before bringing the edges of the respective two sheet elements into contact with each other, at least one nozzle is introduced between edges of the respective two sheet elements, and, after bringing the edges into contact with each other, compressed gas is introduced between the sheet elements via the nozzle. 
     
     
         6 . A method for manufacturing a heat exchanger according to  claim 1 , whereby the sheet elements are joined by the shaping means, along part of the edges of the heat exchanger plate being formed, in such a way that a flange of sheet material extends beyond the joint, and whereby the stacked heat exchanger plates are joined by welding the edges of sheet material together. 
     
     
         7 . A method for manufacturing a heat exchanger according to  claim 6 , whereby the heat exchanger plates are cut free from the sheet material before stacking the heat exchanger plates, and whereby the edges of sheet material possibly sticking together along part of their length as a consequence of the cutting procedure are separated from each other by mechanical separation elements, before welding the edges of sheet material together. 
     
     
         8 . A method for manufacturing a heat exchanger according to  claim 7 , whereby the mechanical separation elements comprise least one mat-like element large enough to cover the corresponding length of edges of sheet material to be separated, and whereby the heat exchanger plates are displaced in a direction normal to their general plane in relation to the mat-like element, so that the edges of sheet material are rubbed over the surface of the mat-like element, thereby causing the edges of sheet material to separate at least partially from each other. 
     
     
         9 . A method for manufacturing a heat exchanger according to  claim 7 , whereby the mechanical separation elements comprise at least one slider that is displaced along at least part of an edge of the heat exchanger plate, thereby causing the edges of sheet material to separate at least partly from each other. 
     
     
         10 . A method for manufacturing a heat exchanger according to  claim 9 , whereby the slider comprises a brush-like element that rubs along the edges of sheet material. 
     
     
         11 . A method for manufacturing a heat exchanger according to  claim 7 , whereby, during shaping of said sheet elements, corners of the heat exchanger plate being formed are formed so that edges of sheet material sticking together at the corners, as a consequence of the cutting procedure, are preloaded such that they automatically separate again just after the cutting procedure. 
     
     
         12 . A method for manufacturing a heat exchanger according to  claim 7 , whereby, during shaping of said sheet elements, welds with a zigzag or wave-like form are being formed along the edges of the heat exchanger plate, so that flanges of sheet material sticking together along said edges, as a consequence of the cutting procedure, are preloaded such that they automatically separate at least partly again just after the cutting procedure. 
     
     
         13 . A method for manufacturing a heat exchanger according to  claim 7 , whereby each sheet element made from plastic material is fed from a coil as a continuous length of sheet material, whereby, after shaping of said sheet elements, they are cut at the circumference of the heat exchanger plate formed except from a number of hinges maintaining the heat exchanger plate carried by the continuous length of sheet material, whereby the continuous lengths of sheet material are subsequently advanced so that the heat exchanger plate is positioned above the mechanical separation elements, and whereby the heat exchanger plate is subsequently displaced in downward direction, thereby punching it out from the continuous lengths of sheet material, whereby the hinges are broken, and thereby passing it along the mechanical separation elements. 
     
     
         14 . A method for manufacturing a heat exchanger according to  claim 1 , whereby the heat exchanger plates are stacked one after each other in a stack by positioning a first heat exchanger plate in the stack and subsequently positioning each following heat exchanger plate beneath the previously positioned heat exchanger plate in the stack, whereby the stack is carried by first support arms during positioning of a heat exchanger plate, and whereby a heat exchanger plate after positioning beneath the stack is lifted up by means of a second support arm, and the first support arms are retracted laterally from the stack, so that the second support arm carries the stack itself. 
     
     
         15 . A method for manufacturing a heat exchanger according to  claim 14 , whereby the first support arms have the form of flaps supported in a horizontal position and hinged about a longitudinal axis, so that they are swung in upward direction and away from each other as a consequence of the stack passing between them during lifting of the stack by means of the second support arm. 
     
     
         16 . A method for manufacturing a heat exchanger according to  claim 1 , whereby the edges of sheet material of adjacent heat exchanger plates in the stack, along the fluid inlets and fluid outlets of the heat exchanger plates, are welded together by means of heated jaws pinching the flanges against each other. 
     
     
         17 . A method for manufacturing a heat exchanger according to  claim 16 , whereby said edges are welded in two subsequent steps, whereby, in the first step, the edges are heated by means of jaws, and whereby, in the second step, the edges are welded together by means of jaws. 
     
     
         18 . A method for manufacturing a heat exchanger according to  claim 16 , whereby said edges of two adjacent heat exchanger plates in the stack are welded after the first support arms have been retracted laterally from the upper one of said two adjacent heat exchanger plates in the stack, so that the second support arm carries the stack during welding. 
     
     
         19 . A method for manufacturing a heat exchanger according to  claim 1 , whereby the heat exchanger plates are welded together partly along their edges so that fluid inlets and fluid outlets are created for fluid passages between the heat exchanger plates, whereby the stacked heat exchanger plates, along edges not forming inlets nor outlets, are joined by welding the flanges of sheet material together by means of bringing sides of the stack of heat exchanger plates into contact with a heated plate ( 40 ,  41 ), thereby welding all heat exchanger plates in the stack together simultaneously. 
     
     
         20 . A heat exchanger produced according to  claim 1 .