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Finned Tubes

DAMAFIN manufactures a wide ranges of finned tubes (with aluminum fins) for the following industrial sectors:
• Oil refineries
• Petrochemical industries
• Natural gas treatments
• Chemical industries
• Power plants
• Gas compressor stations
The choice of a finned tube either for a new installation or for replacement spare is important as it determines the durability and efficiency of the air-cooled heat exchanger. Once you have decided on the tube traits (diameter, wall thickness, length, material) and the fin spacings,the type of fin-mounting to be used shall be decided on.



Bimetallic Extruded

A core tube, or liner, the outside surface of which has been previously polished and carefully digressed, is fitted into an aluminum primary tube.
This tube-in-tube assembly is then fed into the fining machine equipped with three spindles, 120 degrees spaced and each fitted with a gang disc. Maximum working temperature of 3000 C, excellent atmospheric corrosion resistance and excellent mechanical resistance. Such discs, which are stepped in profile and diameter, are first extruded and shape the fin properly and then shrink-fitted the primary tube on its liner. DAMAFIN has developed a high performance bimetallic extruded 11 fins/inch finned tube and an 11.2 inch diameter extruded finned tube which combine a large flow area with long life duration.


“G” Embedded

The fin consists of an aluminum strip whose foot-edge is both tension wrapped and embedded into the primary tube wall. This ensues from the combined action of a set of two discs and a ring spacer arranged at right angles to the primary tube. Operating sequences are as follows: maximum working temperature 4000 C, poor atmospheric corrosion resistance, and acceptable mechanical resistance. The first disc (groover) spins a groove into the tube wall, the ring spacer leads the strip foot-edge into the groove, and finally the second disc (back filler) firmly embeds the strip foot-edge into the groove by “caulking” the groove lip.


Knurled “L”

An aluminum strip is folded to form an L-shape and then is wound around the base tube. The feet of the fins are joined together and cover the whole tube surface. The root of the fin is knurled simultaneously with the inner tube, thus ensuring a tight contact between the fins and the inner tube. Such a result is achieved on the entire width of the fin root, by means of the knurling discs working interdependently.


Double “L”

The aluminum strip foot section is first formed into a double L-stepped shape. This result in a fin base twice as large as that of a single L-shaped, the LL-fin strip is then tension-wrapped onto the primary tube in order to obtain a partial overlapping of the wound fin base. In this way, the primary surfaces are efficiently protected by continuous strip cover, against corrosive environment and cleaning.

“L” (Wrap-On)

The aluminum strip foot section is first formed into an L shape, and is then tension-wrapped onto the primary tube. The wound fin base sections are close to each other in order to ensure a continuous cover on to the primary tube surface. Finally, the fin strip will be fastened at both ends to prevent losing or unraveling.



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