Heat exchanger with welded exchange plates

Abstract

The heat exchanger comprises metal plates ( 6, 7 ) which have been press-formed and assembled in pairs by welding two opposite sides to make modular elements ( 2 ) that are stacked and which define two independent circuits for a first and a second fluid. The two metal plates ( 6, 7 ) of the modular element ( 2 ) are set flatly against each other over a predefined width (L) and are joined by solder ( 12 ) along this width and meant to ensure the mechanical cohesion of the assembly and by another solder ( 13 ) performed along the external edges of the plates and ensuring their sealing. The ends of the plates ( 6, 7 ) are welded to opposite connection partitions forming an exchange block which is itself mounted on four corner posts of the heat exchanger body.

1 . A heat exchanger with welded heat-exchange plates, comprising:
 previously swaged metal plates, assembled in twos by welding on two opposite sides in order to form stacked modular elements defining two independent circuits respectively for a first fluid and for a second fluid, ends of the heat-exchange plates being welded by being placed alongside one another on an edge of openings made in opposite connecting walls, perpendicular to said plates, in order to form an overall parallelepipedal heat-exchange block which is assembled to four posts or corner uprights belonging to a frame of the heat exchanger,   wherein the swaged metal plates comprising each modular element are pressed flat one against another over a predefined width, are joined together by a first weld made in this width and providing mechanical cohesion of the assembly, and are also joined together along their outer edges by a second weld providing the seal.   
   
   
       2 . The heat exchanger with welded heat-exchange plates as claimed in  claim 1 , wherein the two plates are juxtaposed over a predefined width at least equal to fifteen millimeters. 
   
   
       3 . The heat exchanger with welded heat-exchange plates as claimed in  claim 1  or  2 , characterized in that wherein the first weld ( 12 ) is a spot weld or a laser weld or an electrode wheel weld. 
   
   
       4 . The heat exchanger with welded heat-exchange plates as claimed in  claim 1 , wherein the second weld is a weld of a “TIG” or “plasma” type. 
   
   
       5 . The heat exchanger with welded heat-exchange plates as claimed in  claim 1 , wherein each post or corner upright of the frame has a beveled inner edge, the adjacent connecting wall being connected to the post or corner upright in a region of this beveled edge. 
   
   
       6 . The heat exchanger with welded heat-exchange plates as claimed in  claim 5 , wherein the bevel of each post or corner upright is made by a 45° cut of two adjacent faces, over a width of at least ten millimeters. 
   
   
       7 . The heat exchanger with welded heat-exchange plates as claimed in  claim 5 , wherein each connecting wall comprises, in two lateral zones, bellows-like conformations for connection to the post or corner upright, in the region of the beveled edge. 
   
   
       8 . The heat exchanger with welded heat-exchange plates as claimed in  claim 7 , wherein the bellows-like conformations of the connecting walls each comprise two inverted folds together generally forming a sinewave. 
   
   
       9 . The heat exchanger with welded heat-exchange plates as claimed in  claim 1 , wherein the heat-exchange plates comprise “sandwich” metal sheets made on one face by a stainless steel support layer and on the other face by a thin precious metal or alloy, the sealing weld being made only by an overlap between the two layers of precious metal or alloy which protrude from the respective stainless steel support layers.