Measurements of Dustiness – ‘Hairy Arm’ Test …. and Improvements !

November 2013

Dust in bulk materials can have several and varied impacts on users and producers.

Impacts on the producer include:

  • Cost of wasted material.
  • Process time and equipment optimisation.
  • H&S related processing issues.

Cost to the user include:

  • Materials purchased that can be utilised.
  • Processing difficulties.
  • H&S related issues in handling.

So how exactly do you measure the dustiness of a bulk material ?

I’ve seen methods used, for example with desiccant materials, where a QC operative assessment is to plunge an arm into the bulk container, remove it from the bulk and assess the amount of dust caught on the hairs of the arm …… the ‘Hairy Arm’ test.
At FIL, we now offer an instrument DustView II which uses a ‘drop test’ for the bulk being investigated.  Originally developed in conjunction with a major manufacturer of fertilisers, a measured weight of material is placed in a small hopper and a valve opened rapidly to allow the material to drop down a tube, under gravity, impacting on a baseplate mounted inside a chamber below.  This chamber is monitored by an optics based dust monitoring system which fives an output based on obscuration / scattering of a light beam.  The level of scattering is dependent on the dust concentration released during the fall and impact of the process.

Other methods exist and although it is difficult to correlate different systems or link any measured values to explosability limits etc., as an indicator of dust levels and a quality control tool it has proved to be a quick and useful instrument for both manufacturers and users.

EU Decides – Nano Material Definition (measured by number concentration rather than mass)

December 2011

On 18 October 2011 the EU Commission adopted the Recommendation on the definition of a nanomaterial. According to this recommendation a “Nanomaterial” means: A natural, incidental or manufactured material containing particles, in an unbound state or as an aggregate or as an agglomerate and where, for 50 % or more of the particles in the number […]

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The Filtration Society – a source of Knowledge and Support

October 2011

The Filtration Society is a not for profit organisation formed by filtration / separation professionals back in 1964, with an aim to advance and disseminate knowledge on the design and use of filtration and separation techniques in industry, commerce and other walks of life. The Society has a membership covering over 30 countries and continues to offer […]

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Cambridge Particles Meeting – a quick review

May 2011

I attended the Cambridge Particles meeting for the first time, held in the Engineering Department of Cambridge University on Friday 13th May 2011.  I didn’t know what to expect, but the meeting had a friendly academic atmosphere, with scientists and technicians present having a range of interests in aerosol science, although as exhibited by the […]

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Aerosols In the Environment Meeting at the IOP

April 2011

Just got back from attending the Aerosols in the Environment technical meeting at the Institute of Physics in London. This was a joint meeting with the IOP Environmental Group and the Aerosol Society and was well attended by 35 people from a range of academia, meteorological groups and aerosol characterisation instrument suppliers. As some reading this may know, my […]

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What a week that was at Filtech 2011!

March 2011

Well, back in the office after the Filtech 2011 show last week in the lovely city of Wiesbaden. It was an excellent three days with what has been reported as an increase in visitors again since the last show, coming from all over the world.  It’s a long time since I’ve been stood on a stand and […]

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