What do blades refer to in rotating equipment?

• A. Fixed elements for directing flow
• B. Rotating air foils for both compressors and turbines
• C. Static parts that support the casing
• D. Sealing components in mechanical systems

Answer: (B)

Blades in the context of rotating equipment specifically refer to rotating air foils found in both compressors and turbines. These blades play a crucial role in the machinery by converting energy from a fluid into mechanical energy or vice versa. In compressors, blades function to compress the incoming air or gas, increasing its pressure before it enters the combustion chamber or the next stage of the process. In turbines, blades harness the kinetic energy of the moving fluid—whether it's steam, gas, or water—to produce rotational energy that drives the generator or the next system component.

This definition highlights the significance of blades in facilitating the movement and transformation of energy within various rotating equipment devices. The emphasis on "rotating" and "air foils" directly ties the function of these blades to their operational environment, which is essential in distinguishing them from other components in rotating equipment, such as fixed elements, static support parts, or sealing mechanisms.