Dust Suppression Theory & Application

Understanding why dry fog dust suppression works so effectively begins with a single concept: agglomeration. Once you grasp how droplet size and dust particle size interact, the logic of the technology becomes clear.

What Is Agglomeration?

Agglomeration is the process by which smaller particles collide and combine to form a larger mass, which then becomes heavy enough to settle. In dust suppression, this is the mechanism we are working with. The challenge is that agglomeration probability is greatest between bodies of similar size. A 5 micron dust particle travelling in an airstream will simply follow the air current around a large 200 micron water droplet, avoiding contact altogether. Reduce the water droplet to a similar size as the dust particle, however, and the airstream effect weakens, collision becomes likely, and agglomeration occurs.

How Dry Fog Systems Use This Principle

Dry fog dust suppression exploits agglomeration by producing water droplets of 10 microns or less. The Sonicom ultrasonic nozzle achieves this by passing compressed air through the nozzle body, generating an ultrasonic shockwave that shatters the water into an ultra-fine mist. The resulting fog blanket behaves in a way that combines the characteristics of a wet scrubber and a fabric filter: dust particles cannot pass through it without colliding with a droplet, and once contact is made, the particles agglomerate and settle back onto the material body rather than becoming airborne.

What Dry Fog Suppression Controls

The system is effective across a wide range of dust types and particle sizes, from respirable particles as small as 0.1 microns up to larger fugitive dust particles of 600 microns or more. Materials controlled include silica sand, limestone, coal, aggregate, road stone, dried clay, quartz, phosphate, fibreglass and many others.

Applications include primary and secondary crushing, screening, transfer points, loading and unloading facilities, hoppers, feeders, bins, silos, docks, terminals and vehicle loading operations.

Practical and Economic Advantages

Beyond its suppression performance, the dry fog approach offers significant practical benefits. The Sonicom system operates on compressed air at around 5 bar, requiring only small diameter tubing and consuming as little as 5% of the energy of a conventional ventilation-based control system. Installation costs are typically around 40% lower than a comparable bag filter system, and with fewer mechanical components, ongoing maintenance is straightforward and low cost.

For applications where dust control is a regulatory requirement, a health and safety obligation, or simply an operational necessity, dry fog suppression offers a highly effective solution with a favourable total cost of ownership.

For more information on our dry fog systems, visit our Dust Suppression Systems page.