Understanding Triboelectric Terminology - PM 2.5 and PM 10

Posted by Earl Parker on May 13, 2016 11:30:00 AM

Many new dust collector operators and maintenance professionals are understandably baffled when confronted with a whole new emissions compliance terminology. After all, most of their work revolves around mechanical issues, and thus the terminology and methods used to calculate and measure emissions can seem intimidating. 

To take some of the mystery out of these terms we've pulled together explanations of a couple key terms to bridge the gap between the mechanical side and the compliance side of emissions monitoring and control.  The terminology can make even a seemingly simple topic like particle size seem unnecessarily complicated with terms like PM 2.5

What Is Particulate Matter? 

Particulate matter is made of small particles of dust and liquid. It occurs in nature as generic dust (think dusty roads in the desert), and in industrial plants where its created in several different ways. Governmental regulations require companies to collect dust generated by industrial or commercial operations to prevent pollution and to prevent safety hazards created by exposure to dusts (e.g. fire hazards, exposure to toxic dusts, respiratory hazards from high concentrations of airborne dust).

Industrial facilities create particulate matter in several principle ways:

  • Cutting, grinding, sanding materials such as metals, wood, or plastics to make finished products
  • Burning fuels such as wood, biomass and others in furnaces, incinerators and boilers creates combustion byproducts, such as ash, fly ash, soot and smoke made of particulate matter. Additionally, venting certain heat processes such as ferrous and nonferrous smelting and refining also generates particulate matter emissions. 
  • Any kind of dry product conveying such as pneumatic conveying, belt conveyors, truck and rail car loading as commonly found at grain, cement and dry goods facilities. 

What is the Difference Between PM 2.5 and PM 10? pm2_5_graphic_lg.jpg

Dust particles are classified into two main categories, coarse particles measuring between 10 microns to 2.5 microns in size (PM 10) and fine particles 2.5 microns in size or smaller. In the past, pollution regulations primarily covered PM 10. With time, additional research has proven that most of the negative health effects associated with exposure to particulate matter involve exposure to fine particles. As a result, today’s air standards almost exclusively regulate PM 2.5 emissions (PM 10 is still used for reference in many emissions reports, tests, and regulations)

Do Triboelectric Dust Monitors Detect PM 2.5?

With the increased focus on smaller particles pollution control technologies such as fabric dust collectors, air scrubbers, electrostatic precipitators and other methods have required significant improvements in order to comply with tightening regulations. As part of these improved collection methods, improved detection and monitoring technology has been developed in order to effectively monitor and report emissions levels from these control devices in order to confirm their compliance. When it comes to particulate matter emissions monitoring, no technology is more sensitive and reliable at detecting small particles than triboelectric dust monitoring systems. These systems can detect PM 2.5 concentrations in an airstream down to microscopic levels, far beyond what is possible with other methods and technologies. (Auburn Systems TRIBO.dsp 3000 series for example can detect particulate matter in sizes as small 0.4 microns and in concentrations as low as 0.005 mg per cubic meter)

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At times it may seem that a great divide exists between the mechanical side (dust collectors, maintenance, operations) and the scientific compliance side (emissions monitoring, compliance officers, reporting) of dust emissions monitoring and control. In reality, both sides need each other to function, and both groups should take time to learn and understand the basic principles involved in the other. Doing so can greatly improve effectiveness of your plant’s emissions monitoring and control efforts. 


Topics: Air Quality, Dust Collection