Flat tube for a heat exchanger

Abstract

A flat tube for a heat exchanger, formed by bending a sheet metal strip along its length and including: a first wall, a second wall parallel to the first wall, with two complementary side wall portions joining the first and second walls together. The first fall includes a seam extending along the longitudinal axis of the flat tube so that juxtaposed longitudinal edges of the metal strip join together in parallel manner towards the second wall to form a closed profile of the tube. The seam includes a first section fixed to the second wall and extending along the first portion of the seam along the flat tube. The seam further includes a second section extending along the second portion of the seam arranged in series with respect to the first portion and along the longitudinal axis of the flat tube. The second section is separated from the second wall.

What is claimed is: 
     
         1 . A flat tube for a heat exchanger for a flow of a fluid therein, the flat tube being a sheet metal strip bended along its length, the metal strip including longitudinal edges, the flat tube comprising: a first wall, a second wall parallel to the first wall, said first and second walls being substantially flat, two complementary side wall portions joining said first and second walls together, wherein the first wall includes a seam extending along a longitudinal axis of the flat tube so that juxtaposed longitudinal edges of the metal strip join together in parallel manner towards the second wall to form a closed profile of the tube, wherein the seam includes a first section fixed to the second wall and extending along a first portion of the seam along the longitudinal axis of the flat tube, wherein the seam includes a second section extending along a second portion of the seam arranged in series with respect to the first portion of the seam and along the longitudinal axis of the flat tube, wherein the second section is separated from the second wall. 
     
     
         2 . The flat tube according to  claim 1 , wherein the longitudinal edges are inclined with respect to the first section towards either of the side walls portions. 
     
     
         3 . The flat tube according to  claim 1 , wherein the longitudinal edges are on the same level with respect to a surface of the second wall. 
     
     
         4 . The flat tube according to  claim 1 , wherein the seam includes a third section extending along a third portion of the seam arranged in series between the first and the second portion of the seam and along the longitudinal axis of the flat tube. 
     
     
         5 . The flat tube according to  claim 4 , wherein the third section gradually inclines from the first section towards the second section. 
     
     
         6 . The flat tube according to  claim 1 , wherein the flat tube further comprises a first open end and second open end, wherein the second section is located in the vicinity of at least one of the first and second open ends. 
     
     
         7 . The flat tube according to  claim 1 , further including another first section, wherein the second section is located between the two first sections along the longitudinal axis of the flat tube. 
     
     
         8 . The flat tube according to  claim 1 , wherein the seam includes an incision separating at least a portion of the second section from the second wall. 
     
     
         9 . The flat tube according to  claim 8 , wherein the incision is formed substantially in parallel with respect to a surface of the second wall. 
     
     
         10 . The flat tube according to  claim 1  wherein the longitudinal edges of the metal strip include at least one cut-out, wherein the at least one cut-out is formed by removing part of the material from the metal strip. 
     
     
         11 . A heat exchanger comprising a flat tube, the flat tube being a sheet metal strip bended along its length, the metal strip including longitudinal edges, the flat tube comprising: a first wall, a second wall parallel to the first wall, said first and second walls being substantially flat, two complementary side wall portions joining said first and second walls together, wherein the first wall includes a seam extending along a longitudinal axis of the flat tube so that juxtaposed longitudinal edges of the metal strip join together in parallel manner towards the second wall to form a closed profile of the tube, wherein the seam includes a first section fixed to the second wall and extending along a first portion of the seam along the longitudinal axis of the flat tube, wherein the seam includes a second section extending along a second portion of the seam arranged in series with respect to the first portion of the seam and along the longitudinal axis of the flat tube, wherein the second section is separated from the second wall, the heat exchanger further comprising:
 a first manifold, 
 a second manifold, wherein the flat tube is configured to provide a fluidal communication between the first and second manifolds. 
 
     
     
         12 . The heat exchanger according to  claim 11 , wherein the heat exchanger further comprises a secondary flat tube, the secondary flat tube being a sheet metal strip bended along its length, the metal strip including longitudinal edges, the secondary flat tube including: a first wall, a second wall parallel to the first wall, said first and second walls being substantially flat, two complementary side wall portions joining said first and second walls together, wherein the first wall includes a seam extending along a longitudinal axis of the secondary flat tube so that juxtaposed longitudinal edges of the metal strip join together in parallel manner towards the second wall to form a closed profile of the tube, wherein the seam includes a first section fixed to the second wall and extending along a first portion of the seam along the longitudinal axis of the secondary flat tube, the first section extending between open ends of the secondary flat tube. 
     
     
         13 . The heat exchanger according to  claim 11 , comprising a plurality of flat tubes, wherein the first and second manifolds include slots for receiving at least the plurality of flat tubes, wherein the second sections extend through and beyond outlines of the slots on both sides of the heat exchanger. 
     
     
         14 . The heat exchanger according to  claim 13 , wherein the heat exchanger further comprises at least one fin interlaced between any of the flat tubes of the plurality of flat tubes, wherein the second sections extend from the slots at least to the outlines delimited by terminal ends of the fin.