Engineered solution

Dry fog dust suppression

Dry fog dust suppression uses very fine water droplets, typically atomised with compressed air, to capture airborne dust inside enclosed or semi-enclosed points such as transfer chutes, crushers and hoppers while adding little moisture to the material.

Start a guided brief

Talk to an engineer

How dry fog works

Respirable dust particles are so small and light that they follow air currents and slip around large water droplets rather than hitting them. Dry fog systems address this by producing droplets that are much finer, of a size comparable with the dust itself. Nozzles that use compressed air and water, often with an acoustic or two-fluid design, break water into a dense fog. Airborne dust particles collide with these droplets, combine with them, become heavier and settle back into the material stream.

Because the droplets are so fine and the total water flow is low, the material receives far less moisture than with conventional wet spraying. The fog must remain concentrated around the dust source to work, which is why the approach relies on enclosure. Open sides, gaps at belt edges and strong air currents through a chute allow the fog to escape, so the condition of skirt boards, curtains and enclosure panels is assessed together with nozzle placement.

Where it fits and where it does not

Dry fog is usually considered for enclosed or partly enclosed points where dust becomes airborne: conveyor transfer chutes, crusher feed and discharge, screens, hoppers, silo and bunker loading points, and wagon or truck unloading enclosures. It is often preferred where the material or downstream process is sensitive to moisture. In open areas with strong cross-winds the fog disperses before it can act, so wind fences, fog cannons or wet suppression of the material may be more appropriate. Fog is also not a substitute for good chute design and sealing, which reduce dust generation in the first place.

System components and utilities

A typical system includes fog nozzles mounted around the dust source, water and compressed-air supply lines, a control and regulation panel, filtration to protect the nozzles, and an interlock or sensor so that fogging runs only when material is flowing. Water quality matters because the nozzle passages are small. A dependable supply of clean water, compressed air and power at the location are prerequisites, and in cold climates freeze protection may need to be considered. Nozzle positioning is decided from the transfer geometry and the enclosure openings.

When this approach fits

Dust escapes from an enclosed transfer chute, hopper or crusher
The material or process cannot accept significant added moisture
Compressed air and clean water are available near the dust source
Fine, respirable dust is the main concern rather than bulk wetting
Existing wet sprays cause wet material, build-up or carry-back

Design constraints to confirm

How well is the dust source enclosed, and where are the openings?
What material is handled, at what throughput and particle size?
What moisture addition can the material and process tolerate?
Are clean water, compressed air and power available at the point?
What are the transfer geometry, drop height and belt width?
How will nozzles and filters be accessed for maintenance?

Inputs for a site study

Share what you know. Anything you are unsure of can be marked “not known” — our engineers will help confirm it.

Dust source
Material
Throughput
Enclosure
Moisture limit
Water
Compressed air
Power
Site layout

Process

How a project typically runs

Share the dust source, material and site information through an enquiry or the dust discovery journey
We review the brief and list unknowns such as enclosure, throughput and utilities
A site study or drawing review defines nozzle locations and utility routes
A proposal sets out the system scope, utilities required and assumptions
Supply, installation and commissioning proceed as agreed

Spray system installation and commissioning covers the installation of nozzles, pipework, pumps and controls on site, followed by testing, pressure setting and…

Spray and dust-control engineering

Service

Dust-control system maintenance

Dust-control system maintenance keeps spray, mist, dry fog and automated dust suppression systems working through planned inspections, nozzle and filter care, control…

Spray and dust-control engineering

Frequently asked questions

Does dry fog make the material wet?

Dry fog adds much less water than conventional wet spraying because the droplets are very fine and total flow is low. Some moisture is still added, so the acceptable limit for the material and process should be stated at the enquiry stage and checked during design.

Can dry fog be used in an open stockyard?

Generally it is not well suited to fully open areas, because wind disperses the fog before it can capture dust. For open yards, approaches such as wind fences, fog cannons or sprinklers that wet the stockpile surface are usually considered instead.

Why does dry fog need compressed air?

Many dry fog nozzles use compressed air to shear water into very fine droplets. Some designs use high-pressure water alone. The atomising method affects utility demand, so the availability and capacity of compressed air at the location is an important design input.

Not sure this is the right approach?

Answer a few questions about your site. Unknowns are fine — an engineer reviews every brief.