When dealing with abrasive dust such as alumina, silica, and sintered ore, the presence of coarse particles and high airflow velocities in baghouse dust collectors often leads to severe wear on critical components, including filter bags, housing, hoppers, and inlet devices. To mitigate these effects, measures should be taken to reduce the absolute quantity of coarse particles in the gas stream, implement anti-abrasion strategies for dust collection equipment and ductwork, and decrease the velocity of dust-laden air.

 

1.Install a Pre-Separator Before the Dust Collection System

 

Adding a pre-separator before the baghouse dust collector helps remove coarse particles from the gas stream. Pre-separators, such as low-resistance and simple equipment like cyclone separators, are typically used without prioritizing high dust collection efficiency. Common options include gravity settling chambers, gravitational dust collectors, and inertial dust collectors. These devices reduce the burden on the baghouse by removing larger abrasive particles before they reach the filter bags.

 

2.Prefer External Filtration Filters

 

For internal filtration baghouse systems, protecting filter bags requires strict control of inlet velocity, ideally below 1.5 m/s. Extending the filter bag inlet nozzle to 500–700 mm, with 100 mm above the tube sheet and 400–600 mm below, can also reduce abrasion.

 

External filtration systems, however, are more effective for abrasive dust. Clean air exits through bag openings, and dust falls directly into the hopper during cleaning, avoiding filter bag wear. Therefore, external filtration dust collectors are preferred for handling abrasive particles.

 

3.Adopt Lower Filtration Velocity

 

To minimize wear on filter media when handling abrasive dust, it is advisable to use a lower filtration velocity, generally not exceeding 1.0 m/s. This adjustment reduces mechanical stress on the filter material, prolongs its service life, and ensures efficient operation over extended periods.

 

4.Improve Inlet Design of the Dust Collector

 

To reduce wear at the dust removal system’s inlet, the inlet can be designed with a downward inclination to facilitate the natural settling of coarse particles into the hopper. Horizontal inlets can also be equipped with perforated plates or stepped grid flow equalizing and buffering devices to distribute airflow more evenly and lower its velocity. Such measures effectively minimize abrasive damage to the collector's interior surfaces.

 

5.Apply Wear-Resistant Materials at Abrasion-Prone Areas

 

Reinforce areas prone to abrasion, such as the airflow inlet of the dust collector, with wear-resistant materials like ceramic linings, wear-resistant steel plates, or rubber linings. Designing the airflow inlet with a downward tilt helps reduce direct abrasive impact on filter bags. Furthermore, incorporating buffer and diffuser devices at the inlet mitigates the scouring effect of high-velocity airflow.

 

6.Thicken Hopper Steel or Add Rubber Linings

 

Hopper walls are especially vulnerable to wear from abrasive dust. Increasing the     steel thickness or lining the interior with wear-resistant materials such as rubber or  polyurethane significantly improves durability. These enhancements can effectively protect the hopper from the impact and friction of abrasive particles, extending the hopper's service life.

 

7.Additional Anti-Abrasion Measures

 

Increase the thickness of hopper steel plates, use wear-resistant steel for construction, or line the interior with protective materials such as rubber or ceramic plates.

 

Apply wear-resistant rubber linings to valve plates or blades in rotary airlock valves to enhance their resistance to abrasion.

 

By implementing these measures, baghouse dust collectors can effectively handle abrasive dust, significantly reducing the risk of wear, extending equipment lifespan, and ensuring reliable and stable long-term operation.