Extruded Finned Tube
Extruded finned tubes
are bimetallic tubes whose outer aluminium surface is finned by cold plastic deformation.
There are two major types of finned tubes available with us, single metal tubes (also called mono metallic fin tube) and Bimetallic tube (composite extruded fin tube) .
Extruded Finned Tube
The former uses Copper, Aluminum, and Copper Nickel alone. The later has a core tube on the inside made of harder material. In this case, the outer tube is rolled onto the core tube in order to provide for a tight bond and good thermal contact between the two tubes.
Extruded Bimetallic Finned Tubes
Finned tube is composite with iron-aluminum or copper-aluminum tube rolling out the fin, which feathers are tightness, small heat resistance, good heat transfer performance, high strength, small flow losses, strong corrosion resistant performance, not easy to deformation and a long working lifetime in cold and hot condition, etc.
Overall rolling fin is smooth and has no burr, so it is easy to clean. It is easy to make the fin surface wet and cooled with water when makes it cold during heating air-conditioning engineering. In the situation with drying, heating and other heat exchanging, its surface is handles by anodizing, which with beautiful color and luster, and can effectively prevent surface corrosion.
Aluminum rolling finned tube
is rolling as a whole by the aluminum tube, which has the feather that no contact thermal resistance, high strength, thermal shock and mechanical shock, good thermal performance, and considerable expansion heat transfer surface. The heat ex-changer with this kind of finned tube is ahead of the string or around the plate ones.
Aluminum fin is formed from bi-metallic tubes, a base tube and an aluminum muff tube. The fins are formed on a cold rolling process from the wall thickness of the aluminum muff tube. Extruded fin gives very good corrosion protection to the base tube, as the base tube is not visible to the atmosphere in between the fins.
Maximum operating temperature for extruded finned tube is 300 °C.
As a result, the tubes base is completely connected to the main tube. Since these fins never break, deform or loosen, their heating efficiency does not change over time.
Advantages Of This Fin Tubes:
Corrosion resistance in air is very high;
More reliable capacity for thermal transfer.
Fin material is aluminum (standard form) and copper (occasionally).
Tube material is copper, copper nickel, titanium, carbon steel, or stainless steel.
Extruded Fin Tube, Extruded Finned Tube, Aluminum Finned Tubes
The extruded finned tubes
are produced by compressing an aluminum tube, or sleeve, onto the base tube. The bloom is exposed to very high pressures which essentially "grows" the fins into the final fin profiles. This process manufactures an excellent strong joint with great resistance (fin stiffness) as well as exceptional heat transfer capabilities (longevity, temperature range). The advantage of extruded fin tubes are full protection of bare tube against corrosion and fin has high mechanical strength. Extruded finned tubes provide the most stable performance over time as compared to the other fin types. The fin is rolled from an outer aluminum tube by a process using pressure to create a rolled "pressure bond" between the liner tube and fins. The aluminum fin material completely encloses the tube, except at the ends where a tube coating can be applied.
Primarily extruded finned tubes are used in high temperature conditions and corrosive atmospheric conditions, such as operating temperatures less than 300°C or off-shore applications; heat pipes air to air heat exchangers for HVAC applications, air dehumidification in air treatment plants, energy recovery in air exhaust system. This kind of fin design is the least economical as compared to the other fin types; main reason due to the increased amount of aluminum used around 40% also increased labors during the manufacturing. However this increased cost can be compensated if using lower grade parent tube material.
Max. Working Temperature: 600 °F
Atmospheric Corrosion Resistance: OK
Mechanical Resistance: Poor
Fin Material: Copper, Aluminum
Base Tube materials: Any material available, such as Carbon steel Tube, A179, A192, A210, stainless tube A269/A213 T5 T11 T22 304 316
Extruded Fin Tube, Extruded Finned Tubes and Aluminum Finned Tubes