Spiral Steel Fin Tube

SPIRAL STEEL Fin Tube

Fin parameters that matters

Fin height:

Increasing the fin height will increase the external surface area, but this parameter is limited by the following factors. The height of the fin affects the basic parameter of mass flow, which affects heat transfer and pressure drop; the manufacturing limit of the integral fin is much more limited than that of the serrated fin tube; the fin efficiency decreases, and the overall wing The film is more severely degraded than the Serrated Fins; for fins with a fin height of less than 12 mm, integral spiral fins are recommended. If the other parameters are kept unchanged and only the fin height is increased, the heat exchanger cost first decreases, then does not change, and finally increases again. This is because the increase in the heat exchange area is affected by the larger tube spacing effect and lower. The gas flow rate, lower fin efficiency, and lower fluid permeability are offset.

Fin thickness:

Smaller fin thicknesses result in higher fin density, but at the same time reduce fin efficiency and reduce structural stiffness. The minimum fin thickness is typically 0.9 mm. For handling corrosive/lubricating fluids or high temperature fluids, thicker fins are required, up to 4.2 mm thick, and for small diameters, there are some limitations. The most common fin thickness is 1.2 mm.

Fin density (pitch):

In order to obtain the maximum external surface area per unit length, the highest allowable fin density is used, but excessively high fin density causes problems such as excessive pressure drop, incomplete gas permeation, and increased fouling.

The advantages of Spiral Steel Fin Tube:

1. High production efficiency, continuous winding process

2. Low cost, it relies on the characteristics of high-frequency welding itself - skin effect to heat the surface of the fin 

tube to achieve the purpose of welding, no any filler metal material is required in the welding process;

3.The high-frequency current passes only on the shallow surface of the steel pipe, the welding heat-affected zone is small, so thermal calculation does not need to consider the additional wall thickness, and no post weld heat treatment is needed

4. The weld is firm. Under the condition of reasonable equipment configuration and perfect process parameters, the welding between the fin and the steel pipe can be achieved firmly, and it can withstand the thermal shock fluctuation caused by frequent start-up and shut down