Alloys for a heat exchanger tube having an inner protective cladding and brazed disrupter

Abstract

The invention relates to an assembly of two brazing sheets the first one of which consists of a 3xxx alloy clad on one surface with a 1xxx alloy, the second one of which consists of an AA3xxx alloy clad on both surfaces thereof with a 4xxx alloy, which are assembled together by brazing so as to form a disrupted channel for the flow of exhaust gases, in particular for an engine vehicle.

1 - 13 . (canceled) 
     
     
         14 . An assembly of two brazing sheets, comprising:
 a first sheet comprising an AA3xxx alloy clad on one face with an AA1xxx alloy,   a second sheet comprising an AA3xxx aluminum alloy clad on both faces thereof with an AA4xxx alloy,   wherein said two sheets are assembled to each other by brazing, so as to form a closed channel and/or tube with an internal turbulator, inside which exhaust gas can flow, optionally exhaust gas from an automobile vehicle, alone and/or in association with another fluid, optionally air,   and further wherein a face of the channel exposed to said gas is said face coated with said AA1xxx alloy in the first sheet forming the channel, and wherein the second sheet forms the internal turbulator.   
     
     
         15 . The assembly of two brazing sheets according to  claim 14 , wherein said second brazing sheet comprises an aluminum alloy with the following composition (% by weight):
 Si: 0.3-1.0 Fe<1.0 Cu: 0.3-1.0 Mn: 0.3-2.0 Mg: 0.3-3.0 Zn<6.0 Ti<0.1 Zr<0.3 Cr<0.3 Ni<2.0 Co<2.0 Bi<0.5 Y<0.5, other elements <0.05 each and 0.15 total, remainder being aluminum,   And further wherein said second brazing sheet is clad on two faces thereof with an aluminum brazing alloy comprising from 4% to 15% of silicon and from 0.01% to 0.5% of at least one of Ag, Be, Bi, Ce, La, Pb, Pd, Sb, Y and/or Mischmetall,   said two sheets being assembled to each other by fluxless brazing under a protective atmosphere.   
     
     
         16 . The assembly of two brazing sheets according to  claim 15 , wherein said second sheet comprises an aluminum alloy with the following composition (% by weight): Si: 0.3-1.0 Fe<0.5 Cu: 0.35-1.0 Mn: 1.0-2.0 Mg: 0.35-0.7 Zn<0.2 Ti<0.1 Zr<0.3 Cr<0.3 Ni<1.0 Co<1.0 Bi<0.5 Y<0.5 other elements <0.05 each and 0.15 total, remainder being aluminum,
 wherein said second sheet is clad on two faces thereof with an aluminum brazing alloy comprising from 4% to 15% of silicon and from 0.01% to 0.5% of at least one of Ag, Be, Bi, Ce, La, Pb, Pd, Sb, Y and/or Mischmetall,   said two sheets being assembled together by fluxless brazing under a protective atmosphere.   
     
     
         17 . The assembly of two brazing sheets according to  claim 14 , wherein said assembly is provided with at least one fin and/or separator on an outside face of the first sheet forming the channel, said fin and/or separator comprising an aluminum alloy core sheet with the following composition (% by weight):
 Si: 0.3-1.0 Fe<1.0 Cu: 0.3-1.0 Mn: 0.3-2.0 Mg: 0.3-3.0 Zn<6.0 Ti<0.1 Zr<0.3 Cr<0.3 Ni<2.0 Co<2.0 Bi<0.5 Y<0.5 other elements <0.05 each and 0.15 total, remainder being aluminum, clad on two faces thereof with an aluminum brazing alloy comprising from 4% to 15% of silicon and from 0.01% to 0.5% of at least one of Ag, Be, Bi, Ce, La, Pb, Pd, Sb, Y and/or Mischmetall, and said fin and/or separator being assembled on the channel by fluxless brazing under a protective atmosphere.   
     
     
         18 . The assembly of two brazing sheets according to  claim 14 , wherein said assembly is provided with at least one fin and/or separator on an outside face of the first sheet forming the channel, said fin and/or separator comprising an aluminum alloy core sheet with the following composition (% by weight):
 Si: 0.3-1.0 Fe<0.5 Cu: 0.35-1.0 Mn: 1.0-2.0 Mg: 0.35-0.7 Zn<0.2 Ti<0.1 Zr<0.3 Cr<0.3 Ni<1.0 Co<1.0 Bi<0.5 Y<0.5 other elements <0.05 each and 0.15 total, remainder being aluminum, clad on two faces thereof with an aluminum brazing alloy comprising from 4% to 15% of silicon and from 0.01% to 0.5% of at least one of Ag, Be, Bi, Ce, La, Pb, Pd, Sb, Y and/or Mischmetall, and assembled on the channel by fluxless brazing under a protective atmosphere.   
     
     
         19 . The assembly of two brazing sheets according to  claim 14 , wherein the channel is coated on an outside face thereof with a cladding layer made from an AA4xxx alloy and fitted with at least one fin and/ or separator on said cladding layer, and being assembled by brazing. 
     
     
         20 . The assembly of two brazing sheets according to  claim 14 , wherein the channel is made from a core sheet comprising an aluminum alloy with the following composition (% by weight):
 Si: 0.3-1.0 Fe<1.0 Cu: 0.3-1.0 Mn: 0.3-2.0 Mg: 0.3-3.0 Zn<6.0 Ti<0.1 Zr<0.3 Cr<0.3 Ni<2.0 Co<2.0 Bi<0.5 Y<0.5 other elements <0.05 each and 0.15 total, remainder being aluminum,   clad on an outside face thereof with an aluminum brazing alloy containing from 4% to 15% of silicon and from 0.01% to 0.5% of at least one of Ag, Be, Bi, Ce, La, Pb, Pd, Sb, Y and/or Mischmetall, and said channel being fitted with at least one fin and/or separator on the clad, and being assembled by fluxless brazing under a protective atmosphere.   
     
     
         21 . The assembly of two brazing sheets according to  claim 14 , wherein the channel is made from a core sheet comprising an aluminum alloy with the following composition (% by weight):
 Si: 0.3-1.0 Fe<0.5 Cu: 0.35-1.0 Mn: 1.0-2.0 Mg: 0.35-0.7 Zn<0.2 Ti<0.1 Zr<0.3 Cr<0.3 Ni<1.0 Co<1.0 Bi<0.5 Y<0.5 other elements <0.05 each and 0.15 total, remainder being aluminum,   clad on an outside face thereof with an aluminum brazing alloy comprising from 4% to 15% of silicon and from 0.01% to 0.5% of at least one of Ag, Be, Bi, Ce, La, Pb, Pd, Sb, Y and/or Mischmetall, and said channel being fitted with at least one fin and/or separator on said clad and being assembled by fluxless brazing under a protective atmosphere.   
     
     
         22 . The assembly of two brazing sheets according to  claim 14 , wherein said assembly forms part of a heat exchanger. 
     
     
         23 . The assembly of two brazing sheets according to  claim 22 , wherein said assembly forms at least part of a heat exchanger known under the term EGRC (Exhaust Gas Recirculation Cooler) in which only exhaust gas from an automobile vehicle flows. 
     
     
         24 . The assembly of two brazing sheets according to  claim 22 , wherein said assembly forms at least part of a heat exchanger known under the term CAC (Charged Air Cooler) in an EGR (Exhaust Gas Recirculation) loop, inside which a mix of fresh air and exhaust gas from an automobile vehicle flows. 
     
     
         25 . A heat exchanger tube in which exhaust gas flows, optionally automobile vehicle exhaust gas, alone or associated with another fluid, optionally air, comprising an assembly of brazing sheets according to  claim 14 . 
     
     
         26 . A heat exchanger comprising at least one tube according to  claim 25 .