Fog Dust Control

DMS are the Australian representatives for The Raring Corporation USA ADSTM Fog Dust Control Systems

fog dust control dry fog dust suppression system dust extraction with fog

FOG ON A ROTARY RAIL DUMP

FOG ON A PRIMARY JAW CRUSHER

FOG NOZZLE ASSEMBLY

Please visit The Raring Corporation web site for more information
www.raringcorp.com

Understanding Fog Dust Control Technology

ADS™ fog based dust collection systems are highly efficient, patented, in situ, fine particulate scrubbers that use very little water, no chemicals, and do not increase the overall moisture content of the flowing material by more than a few hundredths of a percent.

ADS™ technology is based on the principals of agglomeration of particles of like size and nucleation of sub-micron particles during condensation of water from a supersaturated atmosphere. These are the same principals that nature uses to cleanse the atmosphere.

Merriam Webster defines fog as … “vapor condensed to fine particles of water suspended in the lower atmosphere that differs from cloud only in being near the ground”.New Picture (1)

Clouds are natures’ solution to pollution. Dust and other particles that are delivered into the atmosphere by wind, volcanoes, or by human activities are “collected” by the small water droplets and delivered back to earth as rain. This “collection” is the result of three phenomena: nucleation, agglomeration, and electrostatic attraction.

Nucleation is the process whereby water vapor condenses on a very small particle thus forming the water droPicture1plet.

Agglomeration is the process whereby droplets and particles of similar size collide and form a larger, heavier droplet.

Electrostatic attraction enhances agglomeration when the charges of two nearby particles or droplets are opposite. In nature, water droplets in clouds are often neutral but in storm conditions, the upward flow of warm, humid air rips electrons off of the cloud droplets causing a static differential between areas within the clouds causing lightening strikes when the differential reaches a critical level..

The Raring Corporations’ ADS(TM) dust control system works in much the same way as nature. A cloud is created using sonic air assist nozzles. The dust and fog are contained in a suitably designed environment to permit the collection processes to occur sufficiently. Electrostatic charge is induced naturally through the atomization process. And nucleation occurs due the the dynamics of air movement within the containment.

ADS™ Fog Based Dust Collection Systems

ADS fog based dust collection & dust suppression systems are highly efficient, patented, in-situ, fine particulate scrubbers that use very little water, no chemicals, and do not increase the overall moisture content of the flowing material by more than a few hundredths of a percent.

Principal of Operation
The principal of operation is based on the probability of like-sized water and dust particles colliding, agglomerating, and growing in size and mass. As the agglomerates become larger and heavier, they settle back onto their source where they are carried through the process without any special handling. When water droplets are significantly larger than dust particles, the air displaced by the moving water droplet conveys the dust particle around the water droplet preventing collision.

What is “fog” and why it is needed?
Fog is produced using sonic type air assist nozzles, the only nozzles capable of producing water droplets in the 0 to 30 micron size range at practical pressures and flows. Water droplets in this size range are highly efficient at collecting PM10 dust particles. PM10 are dust particles in the 0 to 10 micron range and are the particles that are most damaging to human health.

Climatic Restraints?
ADS fog technology works in very hot and arid climates and in very cold and wet climates. The tiny water droplets do not freeze under normal cold weather conditions due to their small size – like clouds do not freeze. In hot, dry climates the systems produce their own humid environment limiting the amount of evaporation and allowing the system to function efficiently.

History of Fog Technology
Fog based technology was first commercialized in the early 1970s for the mining industry of Sweden. Studies conducted at the University of Stockholm and later at the Colorado School of Mines and Arizona State University have clearly demonstrated the efficiency of the technology.

How Efficient is ADS Fog Technology?
ADS fog based systems utilizing the features of our fine particulate scrubber patent are at least as efficient as the best dust extraction systems. This has been demonstrated in an independent study conducted at Codelcos’ Andina mine in Chile. In that study, an ADS system efficiency of 99.29% was measured in an underground environment. Numerous other compliance tests have shown zero opacity and very low PM10 emissions.

Using Fog With Other Technologies to Maximize Overall Dust Control
Because fog systems do not increase the moisture content of the source material, it is often necessary to combine fog with water or chemical systems to control dust created at downstream stockpiles or other open loading points. Fog systems should never be used in combination with extraction systems at a single dust source, as the fog will be extracted along with the dust causing problems in the extraction system and reducing efficiency.

Coal Mining Applications

Fog based dust control technology was first used in coal mining applications in 1995 in the Powder River Basin region of the western United States. Today, roughly 300 million tons per annum are mined in that region using the technology and dust extraction is an all but extinct.

Fog systems do not add measurable moisture to the flow of coal, they do not create ice or other freezing problems in cold climates, and they do not require any chemical or especially clean water.

Properly designed and maintained fog systems can achieve 99% dust reduction in many applications.

ADS is the right choice for:Transfer Point

  • Truck dumps
  • Conveyor transfers
  • Crushing and screening applications
  • Lowering wells (rill towers)

Fog is often used in conjunction with passive dust control technologies such as stilling sheds and engineered chutes.

Fog is not a good solution for:

  • Stacking open stockpiles
  • Working open piles
  • Handling hot materials

TRC is the leader in the use of fog for truck dumps with stilling sheds . Contact us for references and a presentation.

TRC’s coal mining customers includes the biggest names in the industry.

Minerals Mining Applications

Fog based dust control technology is commonly used for the control of fugitive emissions at minerals mining installations in dry climates world-wide. We are in copper, gold, silver, manganese, molybdenum, iron , and nickel mines in north and south America, Australia, South Africa, India, and Asia.

Where to Use Fog:New Picture (4)

ADS is the right choice for

  • Truck and rail dumps
  • Truck and rail loading
  • ROM bins
  • Reclaim tunnels
  • Conveyor and feeder transfers
  • Crushing and screening applications

Fog is often used in conjunction with passive dust control technologies such as wind fences, stilling sheds and engineered chutes.

Where To Use Water or Water with Chemical :

  • Open stockpiles
  • Roadways
  • Tailings ponds
  • All other dust sources that can not be enclosed or contained

For best results, water should be added at multiple locations to maximize uniformity of saturation.

We often combine water spray and fog systems to achieve optimum plant-wide dust control.

Our customer base includes virtually all of the major mining and mining engineering companies world wide.

Agglomeration Video

Rotary Dump Video