Dust Control Sprinklers & Water Cannons

Effective dust suppression is essential for maintaining safe and environmentally responsible operations across mining, quarrying, construction, recycling, bulk material handling, and industrial sites. Dust control sprinklers and water cannons provide a reliable and cost effective solution for preventing dust lifting off surfaces and becoming airborne.

Sprinklers and Water Cannons used to suppress dust have different requirements to sprinklers used for agriculture and irrigation due to their requirements for low application rates, high angles, corrosion resistance and to support high pressures.

Dust Control requires small amounts of water to be applied to the surface regularly to prevent dust. This ensures that only the surface is kept wet and water is not wasted by wetting below the surface where dust will lift off. The regular application allow this surface to be kept wet. If excess water is applied it not only wastes water but it can also soften the underlying surface, which for road dust suppression results in damage to the road. Sprinklers used in agriculture are run for long periods infrequently which provides deep water penetration which encourages root growth. Typical rates per application for irrigation are 5 to 40 litres per m2. For dust suppression typical application rates are 0.25 to 0.5 litres per m2. This low application rate for dust suppression requires the sprinklers to have a fast rotation and even application rate.

The requirement for fast rotation is because the sprinkler needs to be able to rotate fast enough so that it can cover the area without applying too much water. Some large impact sprinklers can take up to 10 minutes to rotate 360 degrees. A typical application rate is 10 litres per m2 per hour so this mean that the application rate per pass is almost 2 litres per m2. Some impact sprinklers include an adjustable brake, while some can be adjusted by changing impact arm alignment or weight positions. Some gear drive sprinklers such as those from Sime include fast or dual speed versions which have significant reductions in rotation speed.

The even application requirement has two components - even coverage along the throw from the sprinkler and even rotation along the rotation arc. Most sprinklers are designed for even coverage along the throw from the sprinkler as this requirement is also critical for irrigation. Impact sprinklers have have a very uneven application when considering a single pass due to the way the spray rotates based on the impact of the drive arm knocking the sprinkler around. This is not an issue for agricultural irrigation because the large number of rotations per application even this out. When they are used for dust suppression and run for only 1 or two passes the application can be quite uneven resulting in uneven dust suppression performance. The gear drive such as the Sime Gemini, Mariner, Climber Skipper provide the same application over the full rotation arc. As a result these provide a better dust suppression coverage than impact sprinklers.

Sprinklers are commonly to control dust on stockpiles. Sprinklers used for agriculture usually have an elevation angle of around 25 degrees as this gives the longest throw distance, but mineral stockpiles typically have angles of 40 to 45 degrees. The major sprinkler manufactures offer high angle sprinklers (44 to 46 degree elevation) and sprinklers where the angle of elevation can be adjusted through a range which are referred to as variable angle sprinklers. The following are some of the high angle and variable angle sprinklers available from quality manufacturers:

Nelson Irrigation offer a high angle (43 degree) version of their SR100 and SR150 Big Gun sprinklers and a range of higher angle models (33, 36 and 39 degree) of their SR200 Big Gun sprinklers. Nelson also offer adjustable elevation angle versions (15 to 45 degree) of their SRA100 and SRA150 Big Gun sprinklers.

Sime Irrigation offers a high angle version of their Royal (44 degree) and Ranger (43 degree) sprinklers a number of different models with adjustable angle elevation including the Syrio (18 to 46 degree), Kronos (16 to 46 degree) and Master (15 to 35 degree). They also have the Climber which is a variable angle (18 to 46 degree) gear drive sprinkler.

Komet Irrigation offers a high angle (44 degree) version of their AP101 and AP140 and variable angle (15 to 44 degree) versions of their AP101, AP140, AP160, AP202 Big Volume Sprinklers.

The water in many dust suppression sprinkler applications can be corrosive. This can be due to the use of bore water water (which in some locations can be hypersaline), water that has come into contact with coal (which makes it acidic) or water that has been recycled from processing which can be corrosive for a number of reasons. The larger sprinklers used for dust suppression are usually made from aluminium which is relatively corrosion resistant to normal water quality. To improve this some manufactures use a combination of anodising (process that thickens the natural protective oxide layer on aluminium), powder coating, coating using other corrosion resistant materials or using more corrosion resistant alloys of aluminium. While these can improve the corrosion resistance there are still applications where an aluminium sprinkler is not suitable (ie exposure to sodium hydroxide used in aluminium refining). In these cases plastic sprinklers are most suitable. The following are some corrosion resistant sprinklers.

Senninger manufacture a range of small plastic impact sprinklers (throw distance 12m to 18m) that are designed for harsh mining application such as heap leaching.

Komet supply their Trigon 112 sprinkler which has a throw range from 21m to 51m

Sime have just released a plastic version of the Teknik sprinkler which has a throw range from 40m to 78m which makes it a very useful product for mining dust suppression applications which require the larger distances.

Agricultural irrigation typically uses lower water pressures (<4 bar) to minimise the pumping costs. Mining application typically have much higher and even variable pressures. Care must be taken when selecting sprinklers that they will survive the higher pressures. As a general rule larger sprinklers are designed to support higher pressures, but there are application where smaller sprinklers are required to support these pressures. While it is possible to install pressure reducing valves to protect sprinklers these add cost and complexity to systems with lots of sprinklers. Some manufactures have custom versions to address this such as the Sime High Pressure Skipper which has a brass base in place of its normal aluminium base to allow higher pressure to be used.

If you have a particular dust control application you would like to discuss or would like assistance selecting a suitable sprinkler then please call us on +61 2 6062 3300 or send an email to sales@wetearth.com.au.