Category Archives: Knowledge Base

Sonic fog dust supression

Sonic fog dust supression

It always looks good as the larger dust visible dust is quickly knocked out of the air stream, which immediately wins over the process guys at a demonstration, but be aware of such miracle cures for dust problems for “The devil lies within the fine print” as it were.

The following problems are present in all such systems;

Unless the water is super clean any dust ,organic bacteria and chemical content is atomised and becomes a respirable hazard. ( The human lung is the most sensitive of all our bodily intakes) .

Any dust induced anywhere near the energy zone of the nozzles is also instantly atomised as well thus increasing the content of the dust respirable content and not reducing it which is the primary objective here as health is more important than how an area looks.

The nozzles are destroyed at an alarming rate as well even in the hardest material and respirable metal fragments are also now introduced into the air body as a further toxic agent.

Visually the largest dust particulate is suppressed quite well and one can see an immediate difference in and area.

Wind has a major effect and can simply blow the fog away before it has any chance of collecting any dust and so there is a need for larger enclosures to permit the fog to saturate the contents of the enclosures.

In almost any plant situation the generation of dust is a dynamic process and the dust is being created continuously at a rate greater than one can retain in a fixed enclosure and so the leakage is also continuous. If one is to look at a dust extraction installation then to save on wastage of air extraction one needs to enclose the chute or head end of conveyors adequately to allow the same dwell time as spoken about above, but the essential difference is that because an extraction system is extracting from the enclosure continuously there is no outward leaks as the dust being pumped into the enclosure as a volume is extracted continuously at the same volume if all your calculations are correct and your reading of the plant dynamics and the same for the material being handled are correct.

The actual real use of sonic fog is to humidify and in that regard is extensively efficient with an application mainly cooling stacks and any stack emissions to comply with environmental legislation. Ironically it is in a stack where one actually achieves a better suppression as the atmosphere up there is well away from any place where the fine particulates one is creating can cause an exposure problem.

Author:  Gerry F. Kuhn

Falout Dust 161

Single Bucket DustWatch unit


Analysing for various chemicals and elements in the air using Drager

Analysing for various chemicals and elements in the air using Drager

Q.  What would be the recommendation for doing the following:  (Conduct once off sampling of CO, Lead, Manganese, Mercury, Arsenic, Chromium, Nickel, Benzene, Formaldehyde, Styrene, Toluene and Tetrachloride).


A.  That is quite a list. As it is from an air quality report, I assume that they want it measured in the air at one or more locations. Units of measurement mg/m3 or parts per million in the air (ppm)

None of these can be determined from the fallout dust samples. It is possible to do elemental analysis on the dust to determine the Lead, Manganese, Mercury, Arsenic, Chromium, and Nickel concentrations but this will not meet the requirements or recommendations of the report as the results are given in parts per million or ppm or mass concentration, mg/kg.

My recommendation would be to research how to measure the airborne quantity of each of those chemicals and elements and then do the tests internally following the procedures.

Drager would be my starting point –

Some of the test could be done using tubes from Drager. The tests that cannot be done in this way would then be done in other ways.

From my experience Drager have a list of chemicals that can be tested for using their pump, and the results are very useful to provide an indication of elevated levels if there are any.

By searching google for drager detection selection you will be able to download the pdf that contains the detection selection that Drager offers and if you Google Drager tube handbook then you will be able to download the handbook if required.


Please contact us regarding any queries.

DustWatch CC – Precipitant Dust Monitoring
082 875 0209 or 021 785 6999 (Chris)
083 308 4764 (Gerry)
0866 181 421 (Fax)




Insects and Locusts in fallout dust buckets

Insects and Locusts in fallout dust buckets

Insects and locusts can contaminate fallout dust buckets, especially in swarm or high concentrations of the insects. The strainer used during filtering will remove these from the sample but depending on how long the insect was in the bucket, the water may be further contaminated, making the processing of the sample more difficult, and in some cases the sample will have to be discarded.

Potential solutions are a mesh placed over the top of the bucket. Research into the impact of this has not been published yet, but the logic says that the dust will collect on the mesh and not land in the bucket. The mesh may also impact on the aerodynamics over the lip of the bucket causing more or less dust to be collected. Our initial assumption would be that more dust is collected in this situation.

Please contact us regarding any queries, comments, or suggestions

Fallout Dust Monitoring and SANAS accreditation

DustWatch cc specialises in fallout dust monitoring and will be able to supply the fallout dust equipment, and laboratory equipment required to operate a fallout dust monitoring programme. We also provide training on site or in central location for people on fallout dust monitoring. SANAS accreditation for fallout dust monitoring is not feasible, especially when mines are in remote locations and doing the analysis of the samples in house. There is also no specific SANAS accreditation for just a fallout dust monitoring laboratory, so a laboratory that wants to have this accreditation must also qualify to do the other tests related to obtaining the SANAS accreditation.

Contact us for more information.

“Smoke & Water” – Fire Prevention

“Smoke & Water”

Fire Extinguisher Tutorial

Fire Extinguisher Tutorial

How to Use a Portable Fire Extinguisher Training Video

How to Use a Portable Fire Extinguisher Training Video

Transformer explosion – Fire Prevention

Transformer explosion – Fire Prevention

Educate Yourself – Teaching and Training Resources for the Geoscience Community

Teaching and Training Resources for the Geoscience Community

Check out this site for courses and free educational information on many topics.

The course being focussed on at the moment is Forecasting Dust Storms Version 2.


Webinar Attended – 28 July 2011 Smoke Particulate

The webinar was excellent.  Over 400 people listening to a lecture by a professor and following a power point presentation.  All from the comfort of your own home.

Like any seminar or lecture you have to concentrate and stay awake, but the availability of snacks from your own fridge always helps 🙂

Information about the webinar is available here, and additional information on the topic of smoke particulate matter is shown here.

Certainly a great way to be educated on topics that are not lectured on regularly.