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Deformational cutting

Deformational
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Tube finning

finned tube
finned tube
tube finning
 

Field of application

Heat exchangers for industrial cold-storage plants and commercial air conditioners, cryogenic units, heat exchangers for petrochemical industry and heat power plants and other.

Major advantages

  • Significant increase of heattransfer effectiveness compared to traditional knurling (the largest effect - at boiling and condensation processe)
  • Decreasing of metal quantity and size of heat exchangers up to 1.3…3 times
  • Easy to control geometry of finnig
  • The ability to fin thin-wall tubes
  • The ability to get tube heat exchanger surfaces in the form of pin fins
  • High effectiveness, no waste of material, simple tool
  • Ecologically clean, no lubricated fluid
  • The ability to use standard lathes as well as special machine with extra high productivity
Major technical characteristics
 
 
Parameter Value
Diameter of tube billet, mm 6 - 30
Tube length, m up 6
Initial tube wall thickness, mm from 1,0
Tube material Copper, Brass, Cu-Ni alloys, Aluminum,
Titanium, Low carbon and Stainless steels
Minimum residual wall thickness, mm 0,3
Fin height, mm up to 4 mm (for copper), but not more than initial wall thicknes
Fin pitch, mm 0,2 - 2
Interfin gap, mm 0,01 - 1,5
Surface area increasing, times up to 12 (for copper)
 
 

 

 

Strength test for finned tube

Seam-welded pipe. Stainless steel AISI 304. Initial tube billet: OD=18 mm, wall thickness 1,5 mm.

Fins parameters:

  • pitch 1.0 mm,
  • fin height 1.2 mm,
  • interfin gap 0.45 mm,
  • residual wall thickness 0.75 mm.
    Bursting pressure was 91,2 MPa (930 bar). Destruction occurred in the weld seam on a non-finned site of the tube.
finning for strengthening

Finning increases tube strength

 

 
 
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