Product Overview
The extruded aluminum finned tube is a heat transfer tube in which the fins are formed from the wall of the tube itself rather than attached afterwards. The result is a one-piece section with a continuous metal path from the base tube into every fin, which helps heat move out of the tube efficiently. It is used where air has to be heated or cooled across a compact tube surface.
Integral Fin Construction
During extrusion the aluminum is pressed through a die that forms the tube and the fins in the same pass. Because the fin and the tube share one piece of metal, there is no contact resistance at the joint, and the fin cannot work loose in service. Fin height, fin pitch and base wall can be set within the range the die allows, so the tube can be matched to the air side and the tube side of a particular exchanger design.
Material and Temper
The tube is produced from aluminum alloys chosen for good thermal conductivity and formability, so the section can be bent and the ends can be machined or joined after extrusion. Aluminum keeps the weight of the coil low compared with a copper or steel finned tube of the same surface area, which helps on equipment where the coil is large or has to be carried.
Heat Transfer Behaviour
Integral fins raise the outside surface area available to the air stream, so a shorter tube length can transfer the same amount of heat. The fin pitch controls how closely the fins are spaced, and a wider pitch helps where dust or frost may collect between the fins. Cleaning is easier when the fins are part of the tube, because there is no gap at the fin root for dirt to lodge in.
Base Tube and Fitting
The plain ends can be left round so they can be expanded into a header plate, welded to a manifold or joined with a fitting. Because the finned section and the plain end come from the same extrusion, the base wall stays continuous along the whole length.
Typical Applications
- Heat exchanger coils for heating and cooling air streams
- Condensers and evaporators in refrigeration equipment
- Air coolers, air heaters and drying units
- Radiators and oil coolers in machinery
- Process equipment where a compact finned surface is required
Ordering Information
Please state the base tube diameter, fin height, fin pitch, cut length and quantity when requesting a quotation. The alloy, temper, fin profile and end preparation can be agreed with the supplier, since they depend on the working fluid, the air flow and the way the coil will be assembled. Drawings or samples can be reviewed before an order is placed.
