Fiberglass Reinforced Plastic Fan Blades Combine Form and Function
Hello, and welcome back to our blog! In our previous post, we highlighted some of the limitations associated with aluminum fan blades in industrial cooling tower applications. Because these limitations exist, experts in the cooling tower industry explored other materials that could be used to construct fan blades that were more reliable while delivering the same light-weight design of aluminum blades. From this research, it was found that fiberglass reinforced plastic, FRP, provided many additional benefits that aluminum fan blades could not. In today’s post, we are going to further explore why FRP fan blades are becoming a popular option in cooling tower fan design. We hope that by the end of this blog our readers have a better understanding of the basics of FRP fan blade design.
Industrial Cooling Tower Parts are Important
If you think of an industrial cooling tower like a car, the fan is the motor. The fan is responsible for circulating air within the tower and effectively mitigating the heat produced by industrial processes. To achieve this, cooling tower fans must rotate almost constantly at a high speed, meaning that the entire assembly needs to be able to handle tens of thousands of rotations per minute. FRP fan blades have proved to be an effective component in fan designs and below we have listed a few ways that FRP fan blades outperform aluminum fan blades.

• FRP blades are molded as a single piece, resulting in higher performance and durability than aluminum fan blades.
• FRP fans are set up to be statically balanced, allowing 100 percent interchangeability between fan blades without the need for additional setup. Conversely, aluminum blades must be balanced with weights each time they are replaced.
• The single piece design of FRP fan blades provides uniform stress loading characteristics, resulting in a significantly longer service life with a decreased chance of failure. Aluminum fan blades, because they are made from multiple, separate parts introduce weak points into the entire fan assembly.
• FRP fan blades are more energy efficient than aluminum fan blades.

Given the above benefits, it comes as no surprise that more and more industrial cooling towers are taking advantage of FRP fan blades.
FRP Fan Blades can be Molded Into any Shape
While the above benefits already make FRP fan blades the obvious choice for many industrial cooling tower applications, an additional benefit makes them even more desireable. Because FRP is a moldable plastic material it can be molded into any shape that the manufacturer desires. This means that the manufacturer can design the fan blade to have a shape that more efficiently circulates air through the cooling tower. An ideal cooling tower fan blade will have a non-symmetrical airfoil that includes a variable chord and twist to help compensate for the change in speed present from the tip of the blade to the base of the blade. Additionally, FRP fan blades provide better performance because they are better able to handle the vibrations that are ever present in cooling tower fan blades. Small interruptions in airflow from structural supports, mechanical supports, and the fan’s drive shaft place constant pressure on the fan blades. While aluminum fan blades will eventually succumb to these small interruptions, FRP fan blades are better able to flex and absorb the vibrations.
In summation, while aluminum fan blades are typically cheaper to install, over the life of the cooling tower this cheap installation cost is offset by high failure rates, shorter equipment life span, and increased energy costs. For these reasons, we here at Industrial Cooling Solutions Inc. utilize FRP fan blades in all of our new industrial cooling tower designs because we feel that the quality of the material leads to better overall performance over the life of the cooling tower. If you would like to learn more about our FRP fan blade designs, or you would like to talk to us about your cooling tower project, please visit our website today. We have a long track record of constructing high-quality industrial cooling towers to meet the needs of a wide range of applications and we would be honored to help you with your needs.