Dust Collectors in Industrial Steam Boilers and Its Impact

A Brief Overview of Dust Collectors:

Multi-cyclone dust collectors have been used along with air preheaters and steam boilers in energy generation and other process industries since the 1950s. Gradually, it has evolved in design and purpose, yet its function remains crucial in many process heating applications. In some cases, dust collectors are installed with air preheaters and steam boiler economizers for the purpose of recycling material and to add another layer of erosion protection. Multi-cyclone dust collectors without moving parts use centrifugal force for separating the particulate from the flue gas as it exits the steam boiler. Dust collectors can remove anywhere from 60% to 99% of the debris from the flue-gas stream.

Components of Dust Collection System:

Dust Collector Hoods:

Dust Collector Hoods are an essential component of a dust collector system that can produce remarkable results with minimum modifications. It is important to examine blown, ripped, or broken filter media, cracked filter assembly, airflow speed to ensure the designed airflow, inaccurate installation, separated bag filter, or a mechanical breakdown of the tube sheet due to abrasion. It must be ensured that it is operating in the right position, if the restricted damper is found by hood for balancing.

Ductwork:

Ductwork is used to extract the dirt and air from the accumulating point of the collector. It must be sized precisely for producing a carrying velocity to keep dust moving.

 Explosion Protection Equipment:

An explosion can be caused by a dust collection system preserved incorrectly. A properly designed dust collector managing combustible dust always includes an explosion protection system. The purpose of the explosion protection equipment is to restrain an explosion and reduce hazardous damage.

 Air Material Separators:

An air material separator is a mechanical device to divide the conveying air from the material being conveyed.

Rotary Airlock:

A rotary airlock separates the dust collector hopper externally allowing the collected dust to exit the system. Usual types of airlocks include rotary valves, trickle valves, double dump valves, and knife gates.

 Rotary valves:

The main objective of a rotary airlock valve is to provide an air seal at the outflow opening of the dust collector hopper. It is installed usually between the hopper flow and a conveyor or release bin.

Trickle valves

Trickle valves, also known as vacuum valves, are used for managing the airlock seal on the dust collector tank and for discharging bulk solid material.

 Dust Collector Exhaust Fans:

Dust collection systems require an exhaust fan for stimulating ventilation air from the position of acceleration through the ductwork.

 Corrosion and Erosion of Metal in Dust Collector System:

Dust collectors become ineffective due to significant damage caused by erosion or corrosion. Multi-cyclone dust collectors are impacted by abrasion through fly ash, particulate mass, and high-velocity gas flow that causes corrosion from chemical attacks. In severe cases, an ineffective dust collector leads to the failure of vital equipment like tubular air heaters, induced-draft fans, precipitators, or baghouse components. Additionally, a dust collector’s operating efficiency may drop significantly due to changes in velocity and pressure drop when ash or other particles plug a cyclone or tube. An overload of particulates may also plug other equipment in the path of the flue-gas flow.

Therefore, regular inspections allow temporary internal repairs during the inspection process, prolonging the life of the equipment and delaying its replacement.

Advantages of Regular Maintenance of Dust Collector System:

• Increased efficiency of dust collector.
•  Longer operating life of the components of the dust collector system.
• Reduced energy required to operate fans for air leakage.
• Minimal fan maintenance due to erosion.
• Lower fuel requirements.
• Protection of the pollution control equipment.
• Reduced repair costs for the dust collector system and its components.
• Increased operating time before replacing the dust collector system.
• Protection for air heaters, fans, and ducting.
• Reduced emissions excursions.

Conclusion

Rakhoh Boilers are one of the leading manufacturers of industrial steam boilers in Pune since 1983. Over 38+ years, Rakhoh has successfully installed more than 3000 boilers in 26 countries worldwide. We also provide excellent boiler services like energy audit, boiler automation, steam trap assessment, annual boiler maintenance, fuel conversion, etc.

For more details on our products and services, visit www.rakhoh.com