The best choice for scrubbing heavy non-explosive dust, like iron ore dust, is wet air scrubbing. Compared to traditionally used dry scrubbing systems, wet air scrubbers provide benefits that have a significant positive effect on the production process.

Dry air scrubbers:

> Low average flow speeds – not over 1.5 m/;

> Overall large dimensions – limited mounting zones.

Wet air scrubbers:

> High average flow speeds – 4 m/s and more;

> Lower overall dimensions – possible to install the system directly above the conveyor belt or other high-dust areas.

The water used inside wet air scrubber systems is usually required to not contain solid suspended particles, like small rocks and sand, in order to avoid duct clogging. However, it is not always possible to have access to clean water in the required amounts at iron ore facilities, and the use of contaminated water in traditional wet air scrubbers will lead to reduced air treatment quality and maintenance costs due to an increased wear of the scrubber parts.

Traditional wet air scrubbers have other drawbacks as well. They are highly prone to buildup and require frequent maintenance stops to remove plaque. The buildup that forms inside of the scrubber overtime reduces gas treatment quality. Another problem is wave generation inside the scrubber due to large gas volumes passing through. The fluctuations of the foam layer may lead to the exposure of the grating. In general, the formation of waves is suppressed by placing a stabilized grid directly inside the foam layer or by dividing the gas stream into multiple streams along with running multiple scrubbers simultaneously.

We at Redwood technology have implemented a different approach to foam stabilization that has allowed out wet air scrubber to avoid all of the drawbacks that regular wet scrubber systems have. We have designed a grid that is able to stabilize the foam layer ay high gas flow speeds Рover 100 tom-m3/s. Rigorous testing of the grids at iron ore mine have shown that even after prolonged continuous use over the grids remained buildup-free despite all other surfaces being covered by solid deposits. We have achieved treatment quality of 99.99%.

The grid used inside Redwood technology wet air scrubber makes our system 5 to 8 times more efficient at scrubbing particulate matter that conventional wet scrubbers. Multidirectional gas flows collide within the grid and form additional vortices that significantly increase treatment quality.


The polypropylene dispersive grating unit ready to be installed.


The wet air scrubber dispersive grating after one year of the continuous air treatment process. The gaps in the grating elements are clearly visible.