Finned tubes are used for efficient cooling or heating is required. These kind of extended surface tubes are used for the production of air-cooled heat ex-changers condensers and even convection coils used in furnaces.

Fins are basically external and extended surfaces located or inserted on outside of tubes and or pipes in order to increase the total surface area and thermal efficiency, resulting in compact heat transfer equipment.

Operating temperature limits for the various types of fin-tubes. Finned tubes are used in applications involving the transfer of heat from a hot fluid to a colder fluid through a tube wall considering three factors:

The temperature difference between the two fluids

The heat transfer coefficient between each of the fluids and the tube wall

The surface area to which each fluid is exposed.

So the whole concept of finned tubes is to increase outside surface area. The advantage of finned tubes is that by increasing overall heat transfer rate, the total number of tubes required for a given application is reduced, thereby also reducing overall equipment size and decreasing the cost of the project. In many application cases, one finned tube replaces six or more bare tubes at less than 1/3 the cost and 1/4 the volume.

Application

Oil and gas refineries

Petroleum, chemical and petrochemical industries

Natural gas treatment

Steel making industry

Power plants

Air conditioning

Compressor coolers

Advantages

High fin stability, excellent heat transfer, high operating temperature.

The fin/tube wall contact is constant because of the setting and makes it possible to use a wall temperature of up to 450°C.

The fin is set throughout its length and consequently does not unwind even when partially uprooted.

This kind of finned tube is one of optimum choices for having good effectiveness/cost ratio.

Weakness

The fin is not so strong to resist mechanical damage when external forces applied on fin area

Handling shall be done with care to avoid any damage.

Finned tubes may be damaged while using either steam or high-pressure water for cleaning

As the fins are helically wrapped in grouves, un-finned area is not covered which can be exposed to corrosive media and galvanic corrosion at the base of the fins can be accrued

Tube shall be straight with smooth out side area to make a good finned tube

It is hard to use core tube again when finning is failed.

Fins should be fixed at both ends avoiding un-wrapping