ADS™ Fog Based Dust Collection Systems
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. 

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 and PM2 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, arid climates and in very cold, wet climates. The tiny water droplets do not freeze - 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.

The Cost of Fog Technology.
ADS fog based systems bear a capital cost that is only a fraction of the cost of systems based on extraction and collection in typical applications. Installation, maintenance, and operating costs are also significantly lower.
Fog systems are more expensive than systems using only high pressure water as the atomizing energy source. This is due primarily to the need for compressed air. High pressure water systems, however, are unable to compete with fog for efficiency.

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.

The ADS Multi-Chamber Fine Particulate Scrubber Patent.
In December of 1997, TRC received US patent #5,713,970 entitled "Multi-Chambered Scrubbing Apparatus for Dust Control". The patent covers critical aspects of its ADS dust control system. The patent relates primarily to the use of baffles in conventional conveyor enclosures at material transfer points. The baffles act to create multiple scrubbing chambers within the enclosure. The following improvements to conventional dust control systems installed in enclosures are achieved:

The ADS dust scrubber design depends on more than just the patented baffles. Skirtboards must be designed to provide a tight seal between the enclosure side walls and the conveyor belt, chutes should be designed to minimize differential velocity between the falling material and the outgoing conveyor, and all penetrations into the chute and enclosure must be well sealed.