Lord Fin Tube-Brazing spiral fin tube

What is Brazing spiral fin tube?

Brazing spiral fin tube offers a solid metallurgical bond between fin and tube, making it ideal for rigorous, high-temperature applications. When the tube expands or shrinks due to temperature changes, the brazed bond never relaxes its grip.Brazed finned tubing in similar or dissimilar metals for increased heat transfer efficiency.

Brazing spiral fin tube advantages:

Brazing spiral fin tube offer an alternative to welded fins for applications requiring smaller O.D. or thinner wall tubes with a strong fin to tube bond. The fin material is edge wound on to the tube and then furnace brazed. 

Brazing spiral fin tube appliance

Brazing spiral fin tube are commonly used in applications with metal temperatures up to 650° Fahrenheit, and with special coating, 1200° Fahrenheit.

Brazing spiral fin tube Typical Characteristics:

Fins Per Inch:                2-20 FPI

Fin Height:                   1/8" to 1"

Fin Pitch:                    5 to 13 fins per inch

Fin Material:                 Copper, Stainless Steel, Carbon Steel

Tube OD:                      1/4" to 3" OD

Tube Material:                Ferrous, Some Non-Ferrous

Brazing spiral fin tube processing: 

The processing of the brazed spiral finned tube with two steps. First, the steel strip plane perpendicular to the pipe axis in a spiral way wound on the outer surface of the pipe, and the steel strip ends welded on the steel pipe, and then to eliminate the gap between the steel strip and the steel pipe, welded together with the method of brazing.

Brazing spiral fin tube

Brazing spiral fin tube cost is expensive, so commonly used another method is wrapped around good steel tube into zinc bath in the overall hot-dip galvanizing to replace. The entire hot dip galvanizing, although the bath is not necessarily good to seep into fin and tube between a minimum space, but in the outer surface of the fin surface and the outer tube is the formation of a a complete galvanized layer. The use of the overall hot galvanized spiral fin tube, due to the thickness of the zinc coating (galvanized layer thickness, the zinc layer is strong, easy to fall off), and the zinc liquid can not be all into the gap, so, the combination of fin and tube is still not high. In addition, the heat transfer coefficient of zinc is lower than that of steel (about 78%), so the heat transfer ability is lower. Zinc in acid and alkali, sulfide in the extremely vulnerable to corrosion, so, with galvanized spiral finned tube is not suitable for air preheater (recovery boiler flue gas waste heat).