L-Foot Fin / Wrap-On Fin

Description

L-Foot Fin – Wrap-On Fin

 
L-Foot Tension Wound Finned Tubes also known as Wrap-On Finned Tubes, are used in applications where temperatures do not exceed about 300 degrees Fahrenheit in other words for low-temperature application where some degree of tube wall protection is required. L-Foot tension wound finned tubes consist of thin aluminium fin strip tightly wound helically around the tube circumference. A “foot” is first formed on one side of the fin strip (hence the name L-Foot). The strip is then wound tightly around the tube, with the foot bearing on the tube outer surface. The short horizontal limb of each L is in contact with the base-tube surface to cover it completely. Tension in the fin strip as it is wrapped around the tube serves to seat the fin foot forcefully on the tube, and to hold the fin firmly in place. L-footed finned tubing offers maximum heat transfer at lower temperatures. The unique L-shaped design holds fins rigidly to withstand heat cycling and high velocity air vibration. This fin offers a certain degree of atmospheric protection of the tube wall against corrosion. The broad contact surface between the tube and the finning enhances heat transfer. This fin design is highly efficient yet cost effective.

The ends of the fins are stapled to prohibit the aluminium fin from unravelling, and loosing the contact between the fin foot and the tube. This contact is critical to the operation of the air cooler, since the heat is transferred from the tube wall, through the fin, to the surrounding ambient air.

Advantages:

• Suitable for low-temperature application
• The finning type is the most cost effective method compared to the others.
• The failed fins can be easily removed during production and bare tube can be used again for finning.
• There is no need for make a helical grove over the core tube.
• It is possible to place the fins on a very thin-walled tube with is particularly desirable when using expensive alloys as core tube.
• The tube can withstand a temperature of up to 130°C without the risk of atmospheric corrosion or thermal stress.

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 grooves, 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
• Fins should be fixed at both ends avoiding un-wrapping

Application:

• Oil and gas refineries
• Petroleum, chemical and petrochemical industries
• Natural gas treatment
• Steel making industry
• Power plants
• Air conditioning
• Compressor coolers

L – FOOT FINTUBE SPECIFICATION: