Heat exchanger tube

Abstract

A folded heat exchanger tube ( 10 ) of the type that is rigidified with a pair of abutted 90 degree walls ( 16 ) extending along the interior length thereof, so as to join the lower ( 12 ) and upper ( 14 ) walls thereof, has a separate inner web member ( 20 ) anchored and fixed inside between a pair of curved, out turned feet ( 18 ) on the abutted walls ( 16 ) and the inner surface of the lower wall ( 12 ). A widened and flattened central channel ( 24 ) in the web ( 20 ) is engaged by the under surfaces of the curved feet ( 18 ), and is approximately as wide as the total width of the tow feet ( 18 ).

1 . A heat exchanger tube ( 10 ) comprising an outer shell having a lower wall ( 12 ), a pair of integral upper walls ( 14 ) spaced therefrom, and a pair of abutted walls ( 16 ) brazed together that are integral to and perpendicular to said upper walls ( 14 ), characterized in that, 
 each of said abutted walls ( 14 ) has an out turned foot ( 18 ) integral thereto having a curved undersurface and a predetermined width (F) and,    a separate inner web ( 20 ) has a series of corrugations ( 22 ) brazed between the inner surfaces of said lower tube wall ( 12 ) and said upper tube walls ( 14 ) and a flattened intermediate channel ( 24 ) having a width (C) substantially equal to twice the width (F) of said out turned foot ( 18 ), with said channel ( 24 ) being anchored between, and brazed to, the curved undersurfaces of said out turned feet ( 18 ) and the inner surface of said lower wall ( 12 ), thereby indirectly joining said upper walls ( 14 ) to said lower wall ( 12 ) with said abutted walls ( 16 ) as well as dividing said channel ( 24 ) into a pair of flow passages within said tube ( 10 ).    
     
     
         2 . A heat exchanger tube according to  claim 2 , further characterized in that said abutted walls ( 16 ) are centrally located within said tube ( 10 ) and said channel ( 24 ) is centrally located within said web ( 20 ).  
     
     
         3 . A heat exchanger according to  claim 1 , further characterized in that said tube lower ( 12 ) and upper ( 14 ) walls are coated with braze material on both the inner and outer surfaces thereof.  
     
     
         4 . A heat exchanger according to  claim 1 , further characterized in that said tube lower ( 12 ) and upper ( 14 ) walls are coated with braze material on only the outer surface thereof, and said web ( 20 ) is coated with braze material on both the upper and lower surfaces thereof.