Fans of FRP infusion and fans of extruded aluminum profiles have different materials of construction and characteristics that distinguish them. Some key differences are:
1. Material: FRP (Fiber Reinforced Polymer) infusion fans are made of a composite material that consists of a resin matrix reinforced with glass or carbon fiber. On the other hand, aluminum fans are made of extruded aluminum profiles, which are also lightweight, and they could be considered durable for non-aggressive applications (chemicals and shocks).
2. Corrosion resistance: Extruded Aluminum fans are susceptible to corrosion and may require special coatings or treatments to prevent rust and other forms of deterioration. FRP infusion fans, on the other hand, are highly resistant to corrosion and can withstand harsh environments.
3. Weight: Extruded aluminum fans are heavier than FRP infusion fans, which can affect installation and transportation costs.
4. Strength: FRP infusion fans have a higher strength-to-weight ratio than extruded aluminum fans, which means they can withstand higher loads and stresses without deforming or breaking.
5. Fatigue: The use of composites in various industries has become increasingly prevalent, showcasing their effectiveness in manufacturing critical components. A prime example is the aircraft vertical stabilizer, which is now predominantly constructed using composites. Similarly, FRP infusion fans, composed of advanced composite materials, provide unmatched fatigue resistance, guaranteeing exceptional longevity even in the most demanding operating conditions.
6. Design flexibility: FRP infusion fans can be molded into complex shapes and designs, making them ideal for custom applications. Extruded aluminum fans, on the other hand, have more limited design options.
7. Noise: FRP infusion fans are quieter than extruded aluminum fans due to their composite construction, which allows the construction of blades with aerodynamic features aiming low sound emission.
8. Maintenance: FRP infusion fans require less maintenance than extruded aluminum fans since they are less susceptible to corrosion and damage. If maintenance is required, the composite material is easier to repair in the field with no need for fan disassembling process.
Based on the information above, when selecting a fan for cooling towers and air coolers one question arises, "What is the most suitable fan blade material?"
If you think about performance, then the answer is undoubtedly composite. If the cost is the most important requirement, then aluminum could be the one. FRP infusion fans are the best choice in comparison to extruded aluminum fans because they can be shaped into complex designs that are pre-determined by CFD simulations. By taking advantage of all the aerodynamic features that can be applied in a high-quality fan design, turbulence can be significantly reduced, and the airflow distribution can be perfected, hence higher efficiency levels can be delivered. Noise is also an important parameter, highly dependent on a good aerodynamic design, enhanced by FRP.
To fully appreciate the benefits of FRP infusion fans, it is crucial to understand the importance of each of the four factors mentioned:
1. Tapered Blade Geometry is the gradual blade chord reduction along the spanwise direction of the blade. It improves the airflow distribution compensating for the fan speed variation along the radius of the Fan.
FRP infusion fan
2. Torsion of the blade, like the tapered design, helps balance the lift distribution along the spanwise blade direction, resulting in a more homogeneous flow distribution. The higher pitch angle at the blade root helps to compensate for the low tangential velocity in this region. Thus, it is possible to get the maximum efficiency from each blade section considering the local flow behavior.
In summary, FRP infusion and extruded aluminum fans have distinct advantages and disadvantages. FRP infusion fans are best for heat exchange equipment due to their corrosion resistance, high strength-to-weight ratio, and endless design flexibility. The aerodynamic design of the fan, including blade chord length, torsion, profile, leading edge shape, and trailing edge thickness, can significantly impact performance and noise level. Hence, all factors must be considered when selecting a fan for a specific application.