Spray Scrubbers
Spray scrubbers consist of vertical
empty chambers in which the gas stream is contacted with liquid droplets
in counter-current manner (see Figure - left). The polluted gas flows upward
and the particles collide with the liquid droplets produced by suitable nozzles
located across the flow passage. The droplets then settle by gravity to the
bottom of the chamber.
Horizontal arrangement (cross-flow pattern) is also possible (see Figure - right). Improvement in the collection efficiency can be achieved by placing additional vertical baffles in the spray section. This device is also known as the wetted impingement baffle scrubber.
In a self-induced spray scrubber (see Figure), the gas with entrained particulates flowing at high velocity is passed through the contacting region, whereby atomization of the liquid occurs. The liquid carries with it the particulates and are separated from the gas in the entrainment separator. The liquid so knocked out then flows under gravity back to the bottom of the scrubber, and the particulates settles out from the liquid.