i)  A baghouse, or fabric collector, is the generic name for an air pollution-control device designed to filter dust and other fine particles from contaminated air in commercial and industrial facilities.

ii)  Baghouses control the emission of air pollutants in many industries, such as steel and foundry operations, power plants, chemical production, food manufacturing, and pharmaceutical plants.

iii) Construction and working:-

1. The large funnel shaped container is called the Hooper.
2. The Hooper has a duct through which the dust laden air enters.
3. The air is then drawn through a collection of cylindrical bags. Dust particles settle on the bag to form a layer known as dust cake. The dust cake then has to be removed to allow the normal functioning of the bag house to continue.
4. This air is then expelled to the outdoors through an exhaust stack.

iv)  There are 4 common types of baghouse collectors categorized according to their ability to remove the dust cake:-

1. The pulse jet system – It is a self cleaning type of baghouse. The compressed air causes rapid expansion of the bag’s fabric, shattering the dust cake and forcing it from the bag.
2. The reverse air system – in which the dust cake is removed by the combined forces of an inflow of clean air in the reverse direction (opposite that of the dust-laden air) with the collapse of the bag, which results from a partial shutdown of normal air flow.
3. The shaker system – The bag is mechanically shaken to remove the dust cake. A rod driven by a motor shakes the bag and normal operation is ceased for a short while.
4. The sonic system – A vibration is caused by a low frequency sound generator which removes the dust cake