Q1: Induced draft fans provided in large thermal power plant boilers have __________ blades.

ANS:B - backward curved

Induced draft fans provided in large thermal power plant boilers typically have backward curved blades. Backward curved blades are commonly used in induced draft fans because they offer several advantages for this application:

1. High Efficiency: Backward curved blades are designed to efficiently handle high-volume airflow with low pressure differentials, making them well-suited for the large volumes of air required to exhaust flue gases from thermal power plant boilers.
2. Low Noise: These blades produce less noise compared to other types, contributing to a quieter operating environment in the power plant.
3. Stable Performance: Backward curved blades provide stable performance over a wide range of operating conditions, ensuring reliable operation of the induced draft fan.
4. Reduced Wear: The design of backward curved blades minimizes wear and erosion, increasing the longevity of the fan and reducing maintenance requirements.

• Backward curved