Chemical Engineering - Mass Transfer - Discussion

The temperature and humidity of air is low the Stack effect takes place in the natural draft tower.

So usually we should use natural draft tower.

(Stack effect is the movement of air into and out of buildings, chimneys, flue gas stacks, or other containers, and is driven by buoyancy. Buoyancy occurs due to a difference in indoor-to-outdoor air density resulting from temperature and moisture differences. The result is either a positive or negative buoyancy force. The greater the thermal difference and the height of the structure, the greater the buoyancy force, and thus the stack effect. The stack effect is also referred to as the "chimney effect", and it helps drive natural ventilation and infiltration. ).

Forces draft cooling tower helps in fast movement of the air as the air is at low temperatures it's density will be more so it will be difficult to get the air inside the cooling tower with the help of natural draft cooling tower, so for that purpose forced draft cooling tower is used and as air has low humidity it is eager to take the water vapour at a high rate.

If humidity is very low means the air required more m/c to humidify itself so the temperature transfer range is more than the humidify air, so we require the Natural draft cooling tower than other draft.

I think forced draft use in the temperature and humidity of the air is low.

So, the correct answer is option B- forced draft.