Finned tubular heat exchanger

Abstract

An apparatus and method for fabricating an externally finned tubular heat exchanger assembly comprising two concentric thin walled tubular members defining therebetween an intermediate inner annular fluid flow channel, and positionally fixed therewithin an internal turbulizer strip extending longitudinally in a helical spiral. The tubulizer strip is embossed with corrugations prior to installation into the intermediate inner annular fluid flow channel. The corrugated strip is helically spiraled with sequential bridge gap spaces between adjacent serial turns wherein the corrugations form a series of triangular cross-sectional fluid flow passageways. Turbulizer corrugation expansion, after insertion into the inner intermediate annular fluid flow channel, mechanically anchors the corrugated turbulizer strip to the second inner concentric tubular member that has an end groove to provide engagement connection. The turbulizer is utilized to vary conductance and thus control fluid flow through the tubular inner channel of the second concentric tubular member. External fins are attached to the exterior circumferential surface of the first outer concentric tubular subassembly member to further enhance heat exchange.

1 : A finned heat exchanger assembly formed by the combination of at least two concentric thin walled tubular members comprising: 
 a. a first outer concentric thin walled tubular member having a larger first inside circumference;    b. a second inner concentric thin walled tubular member having a smaller second outside circumference than said larger first inside circumference of said first outer concentric thin walled tubular member, so that when said tubular members are assembled concentrically together, said first outer concentric thin walled tubular member is longitudinally centered axially within said first concentric thin walled tubular member, and said first outer concentric thin walled tubular member and said second inner concentric thin walled tubular member concentrically define therebetween an intermediate inner annular fluid flow channel being coincidental with a portion of the inner channel of the first outer concentric thin walled tubular member;    c. a helically formed, spirally wound turbulizer strip subassembly being constructed with laterally displaced triangular cross-sectional areas to form therein longitudinal triangular flow passageways and said turbulizer strip subassembly adapted to be inserted into said intermediate inner annular fluid flow channel;    d. said helical formed turbulizer strip subassembly being end connection anchored to the sidewall of said second inner concentric thin walled tubular member to positionally locate and stabilize said turbulizer strip subassembly within said intermediate inner annular fluid flow channel;    e. said turbulizer strip subassembly being assembled initially with a predetermined compressive force to first contract, and then after insertion expand to maximize surface contact with both said first outer concentric thin walled tubular member and said second inner concentric thin walled tubular member positioned within said intermediate inner annular fluid flow channel; and    f. at least one end of said turbulizer strip having an end connection anchored through said second inner concentric thin walled tubular member, and said end connection anchoring being adapted to vary the cross-sectional flow area of said second tubular inner circumferential area and the cross-sectional flow area of said intermediate inner annular fluid flow channel.    
   
   
       2 : The heat exchanger, as claimed in  claim 1 , wherein said spirally helically wound turbulizer strip is constructed of a heat conductive metal strip.  
   
   
       3 : The heat exchanger, as claimed in  claim 2 , wherein said helical spirally wound turbulizer strip is fabricated with a uniform truncated apex area.  
   
   
       4 : The heat exchanger, as claimed in  claim 3 , wherein said helical turbulizer strip is fabricated with a corrugated triangular cross-sectional rounded apex.  
   
   
       5 : The heat exchanger, as claimed in  claim 4 , wherein said turbulizer is formed as a uniform helix.  
   
   
       6 : The heat exchanger, as claimed in  claim 5 , having external thermal corrugated rectangular fins to improve heat transfer.  
   
   
       7 : The heat exchanger, as claimed in  claim 6 , wherein said external thermal fins are formed with radial, semi-circular uniform, contoured corrugations to increase heat surface area.  
   
   
       8 : A finned heat exchanger assembly formed by the combination of at least two concentric thin walled tubular members comprising: 
 a. a first outer concentric thin walled tubular member having a larger first inside circumference;    b. a second inner concentric thin walled tubular member having a smaller second outside circumference than said larger first inside circumference of said first outer concentric thin walled tubular member, so that when said tubular members are assembled concentrically together, said first outer concentric thin walled tubular member is longitudinally centered axially within said first concentric thin walled tubular member, and said first outer concentric thin walled tubular member and said second inner concentric thin walled tubular member concentrically define therebetween said larger first inside concentric circumference and said smaller second outer circumference an intermediate inner annular fluid flow channel being coincidentally with a portion of the inner channel of the first outer concentric thin walled tubular member;    c. a helically formed, spirally wound turbulizer strip subassembly being constructed with laterally displaced triangular cross-sectional areas to form therein longitudinal triangular flow passageways and said turbulizer strip subassembly adapted to be inserted into said intermediate inner annular fluid flow channel;    d. said helical formed turbulizer strip subassembly being end connection anchored to the sidewall of said second inner concentric thin walled tubular member to positionally locate and stabilize said turbulizer strip subassembly within said intermediate inner annular fluid flow channel;    e. said turbulizer strip subassembly being assembled initially with a predetermined compressive force to first contract, and then after insertion expand to maximize surface contact with both said first outer concentric thin walled tubular member and said second inner concentric thin walled tubular member positioned within said intermediate inner annular fluid flow channel; and    f. at least one end of said turbulizer strip having an end connection anchored through said second inner concentric thin walled tubular member, and said end connection anchoring being adapted to vary the cross-sectional flow area of said second tubular inner circumferential area and the cross-sectional flow area of said intermediate inner annular fluid flow channel.    
   
   
       9 : The heat exchanger, as claimed in  claim 8 , wherein said spirally helically wound turbulizer strip is constructed of a heat conductive metal strip.  
   
   
       10 : The heat exchanger, as claimed in  claim 9 , wherein said helical, and spirally wound turbulizer strip is fabricated with a uniform truncated triangular cross-sectional apex.  
   
   
       11 : The heat exchanger, as claimed in  claim 10 , wherein said helical turbulizer strip is fabricated with a corrugated triangular cross-section having a rounded apex.  
   
   
       12 : The heat exchanger, as claimed in  claim 11 , wherein said turbulizer is formed in a uniform helix.  
   
   
       13 : The heat exchanger, as claimed in  claim 12 , having external thermal fins to improve heat transfer.  
   
   
       14 : The heat exchanger, as claimed in  claim 13 , wherein said external thermal fins are formed with radial, semi-circular uniform surface corrugations to increase heat surface area.  
   
   
       15 : A method of fabricating a finned heat exchanger assembly formed by the combination of at least two concentric thin walled tubular members comprising: 
 a. fabricating a first outer concentric thin walled tubular member having a larger first inside circumference;    b. fabricating a second inner concentric thin walled tubular member having a smaller second outside circumference than said larger first inside circumference of said first outer concentric thin walled tubular member, so that when said tubular members are assembled concentrically together, said first outer concentric thin walled tubular member is longitudinally centered axially within said first concentric thin walled tubular member, and said first outer concentric thin walled tubular member and said second inner concentric thin walled tubular member concentrically define therebetween said larger first inside concentric circumference and said smaller second outer circumference an intermediate inner annular fluid flow channel being partially coincidental with the inner channel of the first outer concentric thin walled tubular member;    c. forming a helical, spirally wound turbulizer strip subassembly with laterally displaced triangular cross-sectional flow areas to form therein longitudinal triangular flow passageways, and said turbulizer strip assembly and adapted to be inserted into said intermediate inner annular fluid flow channel;    d. securely anchoring said helical formed turbulizer strip subassembly to the sidewall of said second inner concentric thin walled tubular member to postionally locate and stabilize said turbulizer strip subassembly within said intermediate inner annular fluid flow channel;    e. said turbulizer strip subassembly being assembled initially with a pre-determined compressive force to first contract, and then after insertion expand to maximize surface contact with both said first outer concentric thin walled tubular member and said second inner concentric thin walled tubular member positioned within said intermediate inner annular fluid flow channel; and    d. at least one end of said turbulizer strip having an end connection anchored to said second inner concentric thin walled tubular member, and said end anchoring connection structure being adapted to vary the cross-sectional flow area of said second tubular inner area of said second inner concentric thin walled tubular member and the cross-sectional flow area of said intermediate inner annular fluid flow channel.    
   
   
       16 : The heat exchanger, as claimed in  claim 15 , wherein said spirally helically wound turbulizer strip is constructed of a heat conductive metal strip.  
   
   
       17 : The heat exchanger, as claimed in  claim 16 , wherein said turbulizer strip is fabricated with a uniform truncated triangular cross-sectional area.  
   
   
       18 : The heat exchanger, as claimed in  claim 17 , wherein said helical turbulizer strip is fabricated with a corrugated triangular cross-section having a rounded apex.  
   
   
       19 : The heat exchanger, as claimed in  claim 19 , having external corrugated thermal fins to improve heat transfer.  
   
   
       20 : The heat exchanger, as claimed in  claim 20 , wherein said external thermal fins are formed with radial, semi-circular uniform corrugations to increase heat surface area.