Introduction
Coal-fired power plants generate a significant amount of dust during the combustion process. When coal is burned in boilers to produce steam and electricity, fine particulate matter such as fly ash is released into the flue gas stream. If these particles are not properly captured, they can cause severe environmental pollution, damage downstream equipment, and violate emission regulations.
To control particulate emissions, most coal-fired power plants use baghouse dust collection systems equipped with high-performance filter bags. These filter bags capture fine ash particles before the flue gas is discharged through the stack.
This case study describes a coal-fired power plant that improved its dust collection efficiency by installing INDRO dust collector filter bags, specifically designed for high-temperature and high-dust-load environments.
 
Background of the Power Plant
The facility is a 300 MW coal-fired power plant operating in a continuous power generation cycle. The plant burns pulverized coal in large boilers to generate high-pressure steam, which drives turbines for electricity production.
During combustion, large volumes of flue gas containing fly ash particles are produced. These particles must be removed before the gas exits the stack to comply with environmental regulations.
Before upgrading its filtration system, the plant experienced several issues:

• High particulate emission levels
• Frequent filter bag failures
• Excessive pressure drop in the baghouse
• Increased maintenance and replacement costs

To improve dust control performance, the plant replaced its existing filter bags with high-temperature resistant filter bags supplied by INDRO.
 
Dust Collection System Configuration
The plant operates a pulse jet baghouse dust collector, one of the most widely used dust collection systems in coal-fired power plants.
Working Principle

1. Dust-laden flue gas enters the baghouse chamber.
2. Gas passes through the filter bags.
3. Dust particles are captured on the outer surface of the filter bags.
4. Clean air passes through the fabric and exits the system.
5. Periodic pulse-jet air cleaning removes accumulated dust from the bags.

The collected fly ash falls into hoppers at the bottom of the dust collector and is transported for disposal or reuse.
 
INDRO Dust Collector Filter Bag Specifications
To ensure reliable operation under high temperature and heavy dust loading conditions, the following filter bag specifications were selected from INDRO.
Filter Bag Technical Parameters

Parameter	Specification
Filter Bag Type	Pulse Jet Baghouse Filter Bag
Diameter	160 mm
Length	6000 mm
Material	PPS (Polyphenylene Sulfide) Needle Felt
Fabric Weight	550 g/m²
Temperature Resistance	Continuous 190°C
Micron Filtration Range	1–10 microns
Surface Treatment	PTFE membrane coating
Top Style	Snap band
Bottom Style	Double folded bottom

The 160 mm × 6000 mm PPS filter bag is commonly used in large industrial dust collectors due to its high filtration efficiency and strong mechanical performance.
 
Why PPS Filter Bags Were Selected
Coal-fired boiler dust filtration requires filter materials capable of withstanding harsh operating conditions, including high temperature, acidic gases, and abrasive fly ash particles.
PPS (Polyphenylene Sulfide) needle felt was chosen because it offers several advantages for power plant applications.
High Temperature Resistance
PPS filter bags can operate continuously at temperatures up to 190°C, making them suitable for flue gas filtration in coal-fired boilers.
Chemical Resistance
Coal combustion produces acidic gases such as SO₂ and SO₃. PPS fibers provide excellent resistance to these chemicals, preventing material degradation.
Excellent Filtration Efficiency
The needle felt structure combined with a PTFE membrane surface treatment improves dust capture efficiency, allowing removal of extremely fine fly ash particles.
Long Service Life
PPS filter bags maintain stable performance under heavy dust loading conditions, reducing the frequency of filter replacement.
 
Installation and Operation
The INDRO filter bags were installed in the plant's pulse jet baghouse dust collector during a scheduled maintenance shutdown.
Installation Process

1. Removal of worn filter bags and inspection of bag cages
2. Cleaning of the baghouse chambers
3. Installation of new 160 mm × 6000 mm PPS filter bags
4. Inspection of pulse jet cleaning system
5. System restart and performance monitoring

Proper installation ensures that the filter bags are securely attached to the baghouse tubesheet and properly supported by filter cages.
 
Performance Results
After upgrading to INDRO PPS filter bags, the power plant observed several significant improvements.
Improved Dust Collection Efficiency
The PTFE membrane-coated PPS filter bags achieved a filtration efficiency of over 99.9%, effectively capturing fine fly ash particles.
Reduced Emissions
Particulate emissions from the stack were reduced to below 20 mg/Nm³, meeting environmental regulatory standards.
Lower Pressure Drop
The optimized filter bag structure improved airflow and reduced pressure drop across the baghouse system, improving overall system efficiency.
Extended Filter Bag Life
The new filter bags demonstrated a service life of over 24 months, significantly longer than the previously installed filter media.
 
Economic Benefits
The installation of INDRO filter bags provided measurable economic benefits for the power plant.
Reduced Maintenance Costs
Longer filter bag lifespan reduced replacement frequency and maintenance labor.
Lower Energy Consumption
Lower pressure drop across the dust collector reduced fan power consumption.
Improved Plant Reliability
Stable dust collection performance reduced unexpected shutdowns and improved plant operational stability.
 
Typical Filter Bag Specifications for Coal-Fired Power Plants
Based on this case and similar installations, the following filter bag specifications are commonly recommended for coal-fired boiler dust filtration.

Parameter	Recommended Specification
Diameter	130–160 mm
Length	4000–8000 mm
Material	PPS Needle Felt
Surface Treatment	PTFE Membrane
Temperature Resistance	Up to 190°C
Filtration Efficiency	>99.9%

For plants with extremely high temperatures, materials such as P84 or fiberglass filter bags may also be used.
 
Conclusion
Dust filtration is a critical environmental and operational requirement for coal-fired power plants. Efficient baghouse systems equipped with high-performance filter bags ensure that harmful fly ash particles are captured before flue gas is released into the atmosphere.
In this case study, the installation of INDRO PPS needle felt filter bags (160 mm × 6000 mm) significantly improved dust collection efficiency, reduced emissions, and extended filter service life in a coal-fired power plant.
With strong resistance to high temperatures, chemical corrosion, and abrasive particles, INDRO dust collector filter bags provide a reliable and cost-effective solution for industrial dust filtration in power generation facilities.