Sheet metal pipe geometry for minimum pressure drop in a heat exchanger

Abstract

A heat exchanger joint between a pipe and a header wall defines an endless transition for conveying the heat exchange medium closely over a control surface of a radius or a chamfer between the interior surface and the pipe to reduce turbulence and pressure loss. The radiused or chamfered flow control surface expands radially as it opens axially into the interior surface of the header wall.

1 . A heat exchanger assembly comprising; 
 a plurality of flow tubes,    a header tank for distributing a flowing liquid heat exchange medium to and from said flow tubes and presenting a header wall with an interior surface,    a pipe disposed in an opening through said header wall, and    a transition by extending said header wall into said pipe around said opening to present an expanding flow control surface between said pipe and said interior surface of said header wall for conveying the heat exchange medium closely over said control surface between said interior surface and said pipe to reduce turbulence and pressure loss at said transition between said interior surface and said pipe.    
   
   
       2 . An assembly as set forth in  claim 1  wherein said flow control surface is internal with said header wall and expands radially as it opens axially into said interior surface of said header wall.  
   
   
       3 . An assembly as set forth in  claim 2  wherein said flow control surface extends in a circle about an axis for defining a collar for receiving said pipe.  
   
   
       4 . An assembly as set forth in  claim 2  wherein said control surface extends through a radius.  
   
   
       5 . An assembly as set forth in  claim 2  wherein said control surface extends through a cone to define a chamfer.  
   
   
       6 . An assembly as set forth in  claim 2  wherein said pipe and said header wall comprise an organic polymeric material.  
   
   
       7 . An assembly as set forth in  claim 2  wherein said pipe and said header wall comprise metal.  
   
   
       8 . An assembly as set forth in  claim 3  wherein said pipe terminates in spaced relationship to the plane of said header wall.  
   
   
       9 . An assembly as set forth in  claim 3  wherein said pipe includes a bead abutting said collar.  
   
   
       10 . An assembly as set forth in  claim 3  wherein said collar and said pipe are bonded together.  
   
   
       11 . An assembly as set forth in  claim 10  wherein said pipe is secured prior to bonding to said collar.  
   
   
       12 . An assembly as set forth in  claim 3  wherein said pipe is flared outwardly and engages the exterior of said collar defining said control surface.  
   
   
       13 . An assembly as set forth in  claim 12  wherein said pipe includes an enlarged end defining a shoulder for surrounding and engaging the exterior of said collar with said shoulder abutting said collar.  
   
   
       14 . An assembly as set forth in  claim 12  wherein said pipe and said collar include mating undulations extending annularly thereabout for locking said pipe to said collar.  
   
   
       15 . An assembly as set forth in  claim 4  wherein said control surface presents a smooth transition from said pipe into said interior surface of said header wall with a radius or a 30° to 60° chamfer equal to or greater than 2.0 mm  
   
   
       16 . An assembly as set forth in  claim 5  wherein said control surface presents a smooth transition from said pipe into said interior surface of said header wall with a radius or a 30 to 60 chamfer equal to or greater than 2.0 mm.