Wheelfin^tm

Wheelfin™ Design Assures Both Performance and Reliability

Air-x-changers' Wheelfin™ design offers greater heat transfer than the conventional plain fin.

Performance

A spiral, shoulder-type fin with radial openings like the spokes of a wheel, Wheelfin™ achieves superiority over the plain fin by substantially cutting the required heat-transfer surface, yet having the strength and non-clogging characteristics of a smooth fin.

Reliability

Since we introduced the patented Wheelfin™ design in the early 1960's it has proven its reliability in over 90,000 installations.

How Wheelfin™ Works

When fluid passes over a surface, a stagnant layer or film builds up which decreases the heat-transfer rate. Similarly, when air passes over a plain or smooth fin, it forms an air film that reduces the rate of heat transfer to the atmosphere. Wheelfin™'s interrupted surface with its radial openings prevents this film of air from reaching its maximum thickness, increasing the outside film coefficient. At the same time, Wheelfin™ does not increase the turbulence of air passing over the fins. The result is an increase in overall heat-transfer rate without an increase in static pressure or fan horsepower.

Wheelfin™ Advantages

Wheelfin™ can reduce the cooler size and heat-transfer surface requirement for a specific cooling duty. Comparably sized air-cooled heat exchangers with the Wheelfin™ design require less air, reducing power costs. Our comprehensive computerized rating approach utilizes the Wheelfin™ to ensure that the air-x-changer will always provide optimum performance.

Example:

The two graphs indicate the savings when Wheelfin™ is used instead of conventional plain fin tubing and the increased heat-transfer efficiency attainable by using Wheelfin™ in units of equivalent size. The graphs are based on the following typical conditions:

Duty - 2,000,000 Btu/hr
Flow - 400 gpm of water
Temperature range - 165° to 155° F
Ambient - 100° F
Elevation - 1,500 feet

If the section plan area remained constant and the number of rows were varied, the differences between Wheelfin™ and plain-fin surface requirements would be even greater.

Fewer rows permits increased air flow with equivalent horsepower, reducing air temperature rise and increasing MTD resulting in lower surface requirements.

In the same manner, if both the section plan area and the number of rows were maintained, Wheelfin™ would require substantially less air and less fan horsepower.

An important consideration in the evaluation of air-cooled heat exchangers is that a smaller tube normally requires less surface. When compared with a larger diameter tube with a similar fin, the smaller tube has less resistance to air flow, which results in a greater amount of ambient cooling air and higher MTD's with constant fan horsepower. The various manufacturing steps are accomplished more quickly, offsetting the seemingly apparent advantage of using a greater number of tubes with more surface.

Wheelfin™ . . .

Your key to smaller, more efficient coolers.