Vliegasstof: eigenschappen, gevaren en filtratiehandleiding

Fly Ash in Thermal Power Plants

Fly ash dust is a ﬁne particulate by-product generated during the combustion of coal, lignite, petcoke, or biomass in boilers. It is carried by ﬂue gases and must be captured before being released into the atmosphere.

Typical Characteristics

Parameter	Typical Value
Deeltjesgrootte	1–100 µm
Bulk Density	600–1000 kg/m³
Major Components	Silica, Alumina, Iron Oxide, Calcium Oxide
Dust Loading	10–80 g/Nm³

Why is Fly Ash Dust a Concern?

Health Hazards

✓Respiratory irritation
✓Asthma and bronchitis
✓Long-term silica exposure risks

Milieu-impact

✓Air pollution
✓Soil contamination
✓Water pollution

Operational Issues

✓Fan and duct erosion
✓Hopper choking
✓Increased maintenance costs

Fly Ash Filtration Technologies

Elektrostatische precipitator (ESP)

ESP removes ﬂy ash using electrostatic forces.

Voordelen

✓Low pressure drop (10–25 mmWC)
✓Geschikt voor grote gasvolumes
✓Lower fan power consumption

Typical Performance

Parameter	Value
Eﬃciency	98–99.8%
Drukval	10–25 mmWC
Uitlaatgasemissie	30–100 mg/Nm³

Bag Filter (Baghouse)

Bag ﬁlters use fabric media to capture ﬂy ash particles.

Voordelen

✓Collection eﬃciency >99.9%
✓Excellent PM2.5 capture
✓Emissions below 10 mg/Nm³

Typical Parameters

Parameter	Value
Lucht-tot-doekverhouding	0.8–1.3 m/min
DP	100–180 mmWC
Eﬃciency	>99.9%

ESP vs Bag Filter

Parameter	ESP	Zakfilter
Eﬃciency	98–99.8%	>99.9%
Drukval	Laag	Hoger
PM2.5 Capture	Gematigd	Uitstekend
Emissions	30–100 mg/Nm³	<10 mg/Nm³

Best Practices for Fly Ash Control

✓Monitor Differential Pressure (DP)
✓Check stack emissions regularly
✓Maintain ash handling systems
✓Conduct annual ﬁltration audits
✓Select proper ﬁlter media (PPS, PTFE, Fiberglass)

Conclusie

Fly ash dust is a major pollutant in thermal power plants and industrial boilers. Effective control using ESPs or Bag Filters helps plants achieve environmental compliance, improve equipment reliability, and reduce maintenance costs. For stringent emission norms, modern Bag Filters often provide the most reliable solution.

FAQ

What is ﬂy ash dust?

Fine particulate matter generated during fuel combustion in boilers and furnaces.

Is ﬂy ash harmful?

Yes, prolonged exposure can affect respiratory health and the environment.

Which is better for ﬂy ash collection?

Bag Filters generally provide higher eﬃciency and lower emissions than ESPs.

What emission level can a Bag Filter achieve?

Typically below 10 mg/Nm³ with proper design and maintenance.

📖 Read Case Study

Discover how a thermal power plant reduced stack emissions from 120 mg/Nm³ to below 10 mg/Nm³ through an ESP-to-Bag Filter retroﬁt while improving plant reliability and reducing maintenance costs.

CASE STUDY LINK HERE

Vliegasstof: eigenschappen, gevaren en filtratiehandleiding

Vliegasstof: eigenschappen, gevaren en filtratiehandleiding

Typical Characteristics