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Cost-Effective Design of Venturi Scrubber System for Air Pollution Control
Waterman Engineers Australia
Venturi scrubbers are a good option for applications with high temperatures, heavy contaminant loads and corrosive conditions. They operate without a system fan and use liquid spray for entrainment.

The amount of liquid injected into the throat area affects particle collection efficiency. Higher liquid flow rates increase the efficiency of the scrubbing system.

Cost-Effective Design of Venturi Scrubber
Wet air pollution control technologies, like the venturi scrubber system, typically remove air pollutants at high efficiencies, up to 99 percent for particles of 3 um aerodynamic diameter or smaller, according to Pollution Engineering. Venturi scrubbers achieve these efficiencies by forcing contact between a fine mist of water droplets and the polluted gas stream.

This contact is forced through a tight space, such as the throat section of the venturi scrubber constriction, at high velocity. When the cleaning liquid reaches this throat section, it becomes atomized into an enormous number of tiny droplets, creating turbulent mixing between the gas and the water phase. The polluted gas and the water droplets then combine in the diverging section of the throat and are forced to slow down, allowing for particle removal.

Venturi-type scrubbers have several advantages over other wet scrubbing systems. In addition to offering a cost-effective design, they have the added advantage of being easy to install and operate. The system typically requires a single, high-pressure spray nozzle that’s aimed at the throat section of a venturi constriction. The nozzle produces a spray at higher injection rates and higher pressures than those used in a traditional spray tower, but with a reduced amount of liquid being injected per minute.

While simple venturi scrubbers have fixed throat areas, an adjustable-throat version is often used to maintain efficiency over a wider range of flow rates. Adjustable-throat venturis allow the throat area to be changed by moving a plunger up or down, which decreases or increases the annular opening of the throat section and creates more or less turbulence.