A Venturi scrubber is a kind of wet air scrubber, indicating that it utilizes water or another liquid to cleanse the air. It is designed to use the energy of an incoming gas stream to atomize a scrubbing liquid.

Venturi wet scrubbers are the most popular type of scrubbers; they have been used in the industry of air scrubbing for the past 35 years. This popularity is explained by its high efficiency of particle collection, open construction, and the ability to handle large inlet volumes at high temperatures.

A Venturi wet air scrubber consists of three parts. The first one is called a converging section that has an upside-down conical shape. The gas flow enters the wet scrubber through this section; as the area of a converging section decreases, the velocity of gas increases. The next section, a throat section, is a place in the scrubber where cleaning liquid is introduced, and where particle and gas removal happens. The gas, moving at a very high speed, shreds the liquid into a huge amount of very small droplets, which collect pollutants. The third section, a diverging section, is conical in shape: it forces the airflow to slow down and exit the air scrubber.

This technique allows Venturi wet air scrubbers to be used to collect particulate and gaseous pollutants, though it is more effective at removing particles.

Despite the popularity of Venturi scrubbers and their seemingly open and low-maintenance design, it is not devoid of construction flaws. One of them is the possibility of converging section corrosion due to a dry hot gas entering the scrubber. This can wear down the scrubber and cause a breakdown. To avoid that, cleaning liquid is introduced in the first section, instead of the second to cool down the air and stop dust particles from wearing down the surface of the scrubber.

Another problem that can occur is dust and particle collection on the surface of the venturi throat. This section is not easy to get to, and if not cared for properly, can decrease venturi air scrubber efficiency and eventually lead to a breakdown of the scrubber. A solution to this problem is a dispersion of a cleaning liquid onto the surface of the throat to protect it from particle buildup.

A Venturi wet air scrubber shows high efficiency when removing particles of a contaminant from gas, but it is not ideal for gas collection – it is not recommended to use a venturi wet scrubber alone to scrub gas pollutants.

Lastly, the high speed of the gas entering the Venturi wet air scrubber can lead to the entrainment of liquid droplets with a clean gas stream. Special entrainment separators must be used with all Venturi air scrubbers to avoid contamination of a clean gas.

Considering all of the above, Venturi wet air scrubbers are not fully versatile and often require a lot of upgrades to properly function. The cost of upgrades and general maintenance is often higher than expected. Another downfall of using a Venturi air scrubber is the need to replace one type of venturi with another if air scrubbing needs to change (eg. scrubbing of gas contaminants rather than particle ones).

Redwood Technology offers a new type of wet air scrubber – Scroiler. It is superior to the Venturi wet scrubber in many ways. First of all, it requires very little maintenance – the Scroiler can function for up to 5 years without interruption. Secondly, Scroiler is versatile and can be used for any air scrubbing needs. Lastly, the Scroiler is highly efficient and can easily replace any venturi air scrubber.

Scroiler is an innovative wet air scrubber that is just as efficient as any other scrubbing system but is devoid of their limitations. If you would like to purchase Scroiler, please contact us at info@optromix.com.