Dry Fog vs Wet Fog Dust Suppression: Which to Choose?

Both approaches use water droplets to capture airborne dust. The difference is droplet size, how much moisture reaches the material, and what utilities each needs.

How dust capture works

A droplet captures a dust particle most effectively when the two are of similar size. Very fine fog collides with and agglomerates respirable dust; larger droplets mainly wet the material surface so dust does not lift off in the first place.

Dry fog in brief

• Very fine droplets, usually produced with compressed air and water.
• Adds very little moisture to the material.
• Works best in enclosed or semi-enclosed points such as transfer chutes, hoppers and crusher discharges.
• Needs clean water, compressed air and careful nozzle placement.

Wet fog and plain-water sprays in brief

• Larger droplets from high-pressure water or plain-water spray headers.
• Wets the material, which suits stockpiles, conveyors and open points.
• Simpler utilities: water and a pump; no compressed air in most designs.
• Not suitable where the process cannot accept added moisture.

Selection checklist

1. Can the material accept added moisture? If not, start with dry fog.
2. Is the point enclosed? Fog works best where it is contained.
3. Do you have compressed air available near the point?
4. What water quality is available? Fine nozzles need filtration.
5. Is the dust source open to wind? Consider fog cannons, rain guns or wind fences.

Every site is different, so treat this as a starting point. Send us the dust source and utilities and we will recommend a layout.