Bag filters, also known as baghouses, are air pollution control devices that removeparticulate matter from air streams emanating from industrial processes.
They are like giant vacuum cleaners in factories that suck up dust, smoke and otherairborne particles before they can escape into the atmosphere.
But these systems, unlike vacuum cleaners in the home, can handle large volumesof air and very fine particles, some the size of a fraction of a micron.
The bag filter works on a simple principle: dirty air is passed through a porousmaterial, the dirt is left behind and the clean air continues on its way.
It works like a coffee filter, only this one separates tasty grounds from your morningcoffee.
In a bag filter the "filter" is actually a series of long cylindrical bags made of speciallydesigned fabric.
These bags are suspended vertically in a large enclosure (the "baghouse") to trapparticles as the polluted air passes through.
The magic is on the surface and inside the fibres of these bags, where differentphysical mechanisms combine to trap particles of all sizes.
