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GATE 2016 CE (CE1) – Question 29

Air Pollution and Municipal Solid Wastes · Air pollution: pollutants, sources, impacts, control and air quality index · 1 mark · Multiple choice

It was decided to construct a fabric filter, using bags of 0.45 m diameter and 7.5 m long, for removing industrial stack gas containing particulates. The expected rate of airflow into the filter is 10 m3/s. If the filtering velocity is 2.0 m/min, the minimum number of bags (rounded to nearest higher integer) required for continuous cleaning operation is

  1. 27
  2. 29
  3. 31
  4. 32

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Correct answer: (B) 29

Explanation

Convert10m³/s to600m³/min. At filtration velocity2m/min, required fabric area is600/2=300m². Each cylindrical bag supplies lateral area π·0.45·7.5=10.6029m², so300/10.6029=28.294 bags. Round upward to **29, B**, because a fractional bag cannot provide the required area.