Glossary
KPIs and measurements
Particulate matter
Also known as PM, PM10, PM2.5, PM1, particulate.
Particulate matter (PM) is airborne solid or liquid particulate. PM is categorised by aerodynamic diameter:
| Category | Diameter | Health and capture significance |
|---|---|---|
| PM₁₀ | < 10 µm | Inhalable; permit-limited; captured by ESP and baghouse |
| PM₂.₅ | < 2.5 µm | Respirable; tighter permit limits; demands high-efficiency control |
| PM₁ | < 1 µm | Reaches deep lung; most health-significant; hardest to capture |
Smaller PM is harder to capture
ESPs and baghouses both capture larger particulate more easily than smaller. PM₁ capture demands either PTFE-membrane bags (baghouse) or carefully-tuned ESP fields with adequate SCA. Fouling that degrades either system has its first visible impact on fine PM penetration.
Sonic horns and PM control
Sonic horns preserve ESP and baghouse collection efficiency across the operating cycle by preventing the dust-layer thickening or bag blinding that would otherwise compromise fine-PM capture.
Related terms
Related terms
- Opacity (stack)Opacity is the percentage of light obscured by particulate in stack flue gas. The headline visual KPI for ESP performance; continuously monitored and permit-limited.
- Electrostatic precipitatorAn ESP removes particulate from flue gas by charging dust and collecting it on plate electrodes. Sonic horns are widely used to dislodge ash from plates and to keep hoppers from bridging.
- BaghouseA baghouse is the structural enclosure that holds the bags, cages, tubesheet, cleaning system and hoppers of a fabric-filter dust collector. Sized in compartments for online isolation.
- Mass loadingMass loading is particulate mass concentration in flue gas, typically expressed in g/Nm³ or mg/Nm³. The basis for sizing ESP and baghouse equipment.