Plate Heat Exchanger with Exchanging Structure Forming Several Channels in a Passage

Abstract

A heat exchanger with brazed plates including a stack of parallel plates defining a plurality of generally flat fluid circulating passages, closure bars which delimit the passages and distributing means for distributing a fluid to each passage of a first series of passages and means for conveying another fluid to a second series of passages where at least one passage contains organized exchanging structures which form a plurality of channels in the width of the passage and also at least three channels in the height of the passage is provided. The invention is useful for air separation by cryogenic distillation.

1 . A brazed-plate heat exchanger, of the type comprising a stack of parallel plates which define a plurality of fluid-circulation passages of flat overall shape, closure bars which delimit these passages and distributing means for distributing a fluid to each passage of a first series of passages and means for sending another fluid to a second series of passages, in which exchanger at least one passage contains at least one organized exchange structure which forms a plurality of channels in the width of the passage, each channel being in contact with either at least two other channels or at least one other channel and one plate, the exchanger being wherein the structure also forms at least three channels in the height of the passage. 
     
     
         2 . The exchanger of  claim 1 , in which the structure is made up of a plurality of cylinders. 
     
     
         3 . The exchanger of  claim 1 , in which the structure is formed of a single body containing a plurality of channels. 
     
     
         4 . The exchanger of  claim 1 , in which a channel has a hydraulic diameter of between 1 and 6 mm. 
     
     
         5 . The exchanger of  claim 1 , in which a channel has a hydraulic diameter of between 200 μm and 1 mm. 
     
     
         6 . The exchanger of  claim 1 , in which a channel has a hydraulic diameter of less than 200 μm. 
     
     
         7 . A cryogenic separation apparatus comprising at least one exchanger of as claimed in  claim 1 . 
     
     
         8 . The cryogenic separation apparatus of  claim 7 , in which a main heat-exchange line and/or a vaporizer-condenser and/or a supercooler is said brazed-plate heat exchanger, of the type comprising a stack of parallel plates which define a plurality of fluid-circulation passages of flat overall shape, closure bars which delimit these passages and distributing means for distributing a fluid to each passage of a first series of passages and means for sending another fluid to a second series of passages, in which exchanger at least one passage contains at least one organized exchange structure which forms a plurality of channels in the width of the passage, each channel being in contact with either at least two other channels or at least one other channel and one plate, the exchanger being wherein the structure also forms at least three channels in the height of the passage.