Noise produced by cooling fans (employed in air cooled heat exchangers or cooling tower) is mainly caused due to the turbulence created by blade passage through air. It can be reduced by use of a slower fan_________________?
Correct answer: C. Both A. & B.
- A. With greater number of blades
- B. Of increased diameter
- C. Both A. & B.
- D. Neither A. nor B.
Explanation
A larger fan with more blades can deliver the required air flow at a lower rotational speed, reducing blade-passage turbulence and noise. Therefore, both increased blade number and increased diameter are useful.
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