Orifice scrubbers are similar to venturi scrubbers in that the gas stream flows at high velocity through a narrow section (orifice) to atomize the liquid into droplets. The gas moves through pools of scrubbing liquid at high speeds before it enters the orifice. As it exits, droplets and pollutants are removed through impingement (collision) on a series of baffles.
Orifice scrubbers have the advantage of low water recirculation rates. Some manufacturers provide units with adjustable orifices for changing the impingement velocity.