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) .
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.