Lord Fin Tube-Perforated Finned Tubes

What is perforated finned tubes?

Perforated Finned Tubes maximize heat transfer by increasing the air flow across the finned area of the tube. Uniform perforations are created in the fin as it passes through the machine. These perforations are arranged like spokes of a wheel and can manufactured in Embedded and L-Foot fin configurations. Perforated Fins can manufactured out of aluminum or copper.

Perforated finned tubes size range:

Tube Sizes: 9/16″ O.D. to 2″ O.D.

Fin Heights: ¼” to 1″

Fin Pitch: 4 to 13 fins per inch

Perforated finned tubes production and shape: 

This enhancement to the fin face creates slits much like the spokes of a wagon wheel or a small “tear drop.” The fin is preformed by a set of rollers and when it passes through the forming area of the spindle roll and primary forming roller the “tear drop” or spoke opens up. There is no loss of material.

The enhancement can be done in any type of Wrap-On (W/O), Overlapped Footed Fin (OLFF) or Imbedded aluminum or copper fin. Some tooling is different for W/O and for Imbedded perforated fins. Please refer to the appropriate section in this catalog.

The slit or “tear drop” increases heat transfer and can reduce the required amount of heat transfer surface. Each end user would need to determine the percentage of improvement offered by this enhancement over the plain fin. The industry has also accepted that this type of enhancement reduces the amount of air required and therefore decreases power costs.

Perforated finned tubes Typical Characteristics

Perforated Fin: Available for any Aluminum or Copper Fin

Fins per Inch: 4-12 FPI

Tube Material: Ferrous, Non-Ferrous & Some Alloys

Fin Contact: Primary Fin selection determines fin contact

Type of Service: Primary Fin selection determines service level

Maximum Tube Wall Operating Temperature: Primary Fin selection determines the temperature

Maximum Tube RPM on 1” Tube: 3000

For a finned-tube heat exchangers (FHEXs) with large fin pitches, the enhancement of air-side heat transfer performance by using perforated finned tubes. The effects of the perforation size and number on the air-side factor and heat transfer rates of the FHEX are analyzed in detail at different large fin pitches.

Perforated Finned Tubes Shape