1. Classification by structural type of the heat exchanger fin tube
In terms of structural type, finned tubes can be divided into two basic types: longitudinal and radial. Other types are the development and deformation of these two types. For example, large spiral angle finned tubes are close to longitudinal and small spiral angle finned tubes are close to radial. The shapes of fins are circular, rectangular and needle. In addition, the fins can be arranged outside the tube, which is called the outer finned tube; It can also be arranged in the tube, called inner finned tube or both inside and outside.
2. Classification by manufacturing process of the heat exchanger fin tube
According to the manufacturing process, finned tubes can be divided into integral finned tubes, welded finned tubes, high-frequency welded finned tubes and mechanically connected finned tubes.
(1) Integral finned tube is made of casting, machining or rolling, and the fin and tube are integrated.
(2) Welded finned tubes are manufactured by brazing or inert gas shielded welding. Modern welding technology can connect fins of different materials together, and can make fin tube simple and economical. It has good heat transfer and mechanical properties, and has been widely used. Because the residue in the weld is not conducive to heat transfer and even cause fracture, the welding process quality must be guaranteed in the production of this kind of finned tube.