ONYX NON CHEMICAL DUST SUPPRESION SYSTEMS

ONYX-ARALCO USA is the only company offering a chemical-free dust suppression system.

Dust Suppression  Systems are widely used to control fugitive dust in processes such as loading and unloading of raw materials, in  primary and secondary crushers, screening, conveyors transfer points, in mining operations, cement industry, siderurgical, rock aggregates for construction industry, coke handling including fly ash as well as in food industry, chemical, paper industry, textile,  metals and a broad range  of other industries.

Control of the dust particles is accomplished by applying Dry Fog that is produced by feeding water and compressed air in a nozzle where they are mixed in powerful sound waves.

It is known as Dry Fog due to the fact that it uses neither small quantities of water with no mud formations nor increase of moisture content in the materials; it does not form obstructions or conveyor belt wetting or accompanying tracking problems. Energy is created by compressed air, therefore no chemicals are required for its operation, hard water does not affect quality of Dry Fog, It does require free of solids water.

Dry Fog consists of millions of submicron water droplets that agglomerate in a size equal to the size of dust particles making them heavier and precipitate in the conveyor or equipment. Microscopic water droplets evaporate leaving dry materials with no water tracks. The water applied during the process increases  no more than 1% the moisture content in most of the cases.

Environmental Protection Agency in the United States mentions the use of Dry Fog Systems as a means to suppress.

Fugitive dusts. The document “Techniques to Control Particulate Matter” refers to the use of dry fog in belt conveyor transfer points. “Dry Fog is a device to control fugitive dust emissions coming from conveyors transfer points. In the dry fog device, fine water droplets of micrometric size are generated by nozzles. Water wets material and agglomerates dust particles in big enough sizes to permit precipitation. Once the small water droplets and dust particles reach the belt conveyor, water evaporates leaving dry material.

Dry Fog (MR) Systems operates as follows:

Atomizing nozzles generate a dense fog of water droplets that immediately occupy the air volume of the confinement. This way the existing dust does not dissipate. In the remote case that dust does dissipate it will collision with fine water droplets.

In order to have an effective collision of water droplets and dust particles both have to be same size it means water droplets to be as fine as dust particles. Dust particles are agglomerated creating a bigger and heavier particle the one that is carried on the belt conveyor, therefore eliminating the dust handling problem.

Nozzles for Dry Fog (MR) use compressed air for atomizing the water. This design permits nozzles to produce water droplets as small as one micron, the ones don’t wet the product, eliminating mud formations.

Dry Fog (MR) Systems don’t use chemicals neither tenso- actives eliminating harm to involved equipment or process. Dry fog don’t generate any mud y both air and water consumption may be regulated. The water droplet size (1 micron or lesser) is such that it evaporates at  temperatures in the near by of 30°C. One water droplet occupies a volume of one cubic meter after atomization.

A Dry Fog System consists of:

1.      Confinement

2.      Bars assembly and atomizing nozzles

3.      Valves rack and control cabinet

4.      Air and water supply

1.- Confinements

Located at points where dust is generated such as conveyors transfer points, chutes, rock crushers, a proper confinement may help to reduce up to 50% disperse dust

2.- Bars assembly and atomizing nozzles

Two bars and nozzles form the device to apply air and water, valves regulate flows of air and water going into each bar, normally one or two bars assemblies are located per confinement.

3.- Valves’ Rack and Control Cabinet

Manually or automatically, valves for air and water supply are activated either one or more bars simultaneously, by means of solenoid valves. Valves´ rack includes one Control Cabinet, Pressure regulators, water filter and manually operated valves.

     4.- Air and water supply

Consumption of air and water depends on number of atomizing nozzles, water requirements are minimum and no solids in suspension must carry on. Hard water can be used with no detriment in quality of dry fog produced considering that system don’t use chemical or additives.