What kind of dust collector do you need for abrasive dust? Heavy, abrasive dust produced by surface preparation, abrasive blasting, mining and mineral processing, seed cleaning and separating (e.g., rice hulling), and other industrial processes creates challenges for dust collection. Look for these key features in your dust collector and ductwork to protect your filters, extend the service life of your collector and reduce your maintenance burden.
Designing a Dust Collection System for Abrasive Dust
A dust collection system for abrasive dust includes not only the industrial dust collector itself but also the ductwork, hoods and enclosures, and ventilation and makeup air systems. The entire system must be designed according to ACGIH principles for collection of heavy, abrasive particulate. An industrial ventilation engineer will look at your processes, facility layout, dust type and volume, and clean air goals when designing your dust collection system.
RoboVent Senturion was designed with difficult applications like abrasive dust in mind. Senturion’s modular design allows it to be easily adapted for abrasive dust. It can be paired with advanced PleatLock or Endurex filters for optimal filter life. Senturion features:
- Heavy-duty cabinet construction with 7- and 11-gauge steel, powder-coated inside and out, with optional UHMW lining.
- A modular design that can be scaled up for heavy-duty dust control and outfitted with abrasion-resistant options including drop-out boxes, abrasion-resistant air intakes and chrome-plated rotary valves.
- Ability to segment the dust collector to enable maintenance without shutting down the whole unit.
- Flexible options for collection bins (including 55-gallon drums) or connection to a conveyor system for collection of very heavy dust loads.
- An advanced filtration system for the smallest footprint per CFM in the industry.
Looking for a dust collection solution for abrasive dust? Talk to a RoboVent solutions specialist today.
Challenges in Dust Control for Abrasive Dust
Abrasive dust is tough on your dust collection system. Coarse, abrasive particulate causes excess wear on the filters, ductwork and the dust collector itself.
- Filters: Abrasive dust will tear through filter media quickly. Small microtears and holes allow unfiltered air and contaminants to escape past the filters. This may put the facility out of compliance with OSHA indoor air quality (IAQ) regulations or EPA emissions limits.
- Dust collector intakes, cabinet and components: The air intake and filter cabinet can take quite a beating from heavy, abrasive dust. Abrasive dust can quickly wear down standard powder coatings, leaving the dust collector vulnerable to corrosion. It will also wear down other components, such as valves between the dust collector cabinet and collection bin.
- Ductwork: Abrasive dust is tough on ductwork, too. Over time, abrasive dust can wear through ductwork and create leaks that allow dust to escape and interfere with air velocity.
Considerations in Dust Collector Design for Abrasive Dust
There are several considerations to keep in mind when selecting an industrial dust collector for abrasive dust. The final solution will depend on several factors:
- What is the total volume of dust you are collecting?
- Is the dust combustible?
- Is the dust hazardous to human health?
- Does the dust have a high moisture content?
- Is it important to collect fine and ultrafine particulate in addition to coarse, heavy dust particles?
- Will the collector be located inside or outside?
- Will filtered air be exhausted to the outdoors or into a facility?
The dust collection system should be designed to:
- Extend the life of filters
- Reduce wear and tear on the dust collector and ductwork
- Minimize maintenance requirements
The first step in extending filter life is selecting the right filter media. Abrasive dusts require a durable filter media that sheds dust easily.
- The first row of filters will take the most impact from abrasive dust. Consider using a high-quality spunbond polypropylene filter media for the first row and a less-expensive cellulose media for subsequent rows.
- Coated filters are more durable and shed dust easily. A PTFE-coated filter media provides superior wear and dust shedding.
- If moisture is an issue, make sure the filter media is appropriate for collection of wet, heavy dust.
Even the most durable filter media won’t last long if it is pounded directly by coarse, abrasive particulate. To extend filter life, look for features that prevent the heaviest and coarsest dust from reaching the filter cabinet.
- Drop-out boxes are used to slow the air velocity so that heavier particles can fall out of the air stream. The drop-out box may be a special chamber oriented right before the filter cabinet. Alternatively, the first row of filters may be removed from the filter cabinet to allow the cabinet itself to act as a dropout box. Heavy, coarse particles fall out of the airstream into a hopper and are collected in the collection bin.
- Baffle systems can also be used in the air intake to prevent heavy dust from reaching the filters. Baffles physically block the passage of heavier particles, while lighter particulate follows the airstream around the baffled to the filters. Heavy particles caught by the baffles are directed into the hopper and collection bin.
- Cartridge filters should be oriented vertically to allow more efficient shedding of heavy abrasive dust.
- The dust collector should have a highly efficient pulsing system to pulse heavy dust off the filters and into the collection bins. Look for an advanced pulsing system with engineered pulse nozzles that provide even pulsing down the entire length of the filter. Automated pulsing systems that turn on in response to filter loading (as measured by pressure drop across the filters) cut down on energy use and maximize efficiency.
The entire dust collection system must be designed with abrasion resistance in mind.
- The dust collector cabinet should be constructed using a heavy-gauge steel. Powder coating provides some protection from abrasion along with corrosion resistance.
- For highly abrasive applications, powder coating alone may not be enough. A heavy-duty, abrasion-resistant lining may be needed for the filter cabinet. Ultra-High Molecular Weight (UHMW) plastic provides long-lasting protection for abrasive applications. Other spray-on coatings, such as Rhino Lining and super-durable powder coatings, are also available.
- An abrasion-resistant air intake will be needed. The inlet, inlet baffles and the panel immediately after the intake may also have a UHMW coating or Rhino lining.
- Ductwork should be heavy-duty steel and can be lined for extra protection. Wear points in the ductwork (such as elbows) should be inspected frequently and replaced when they show signs of excessive wear.
- Rotary valves used between the hopper and the collection bin should be chrome plated to hold up to abrasive dust. We recommend an oversized (e.g., 12 x 12”) rotary valve with a low RPM for some abrasive applications. They should be inspected regularly and changed when they show signs of wear.
Applications that produce high volumes of heavy, abrasive dust, such as mining or abrasive blasting, require special features to reduce the maintenance burden.
- The dust collection system should allow segmentation so that one part of the unit can be shut down and maintained while other parts are still operating.
- Use rotary valves to allow bins to be changed without shutting down the collector.
- If you are collecting very large volumes of dust, look for a system that accommodates multiple collection bins or a conveyor system that will convey dust to large storage containers for proper disposal.
- A specialized hopper with steeper sides will allow dust to fall into the collection bins more efficiently.
Combustion and Fire Safety
Some types of abrasive dust are also explosive, such as seed processing dust and some mineral ores. When collecting combustible dust, the dust collector must be equipped with explosion safety features that comply with OSHA and NFPA safety standards. A deflagration system limits damage if a combustion event occurs inside the dust collector. Dust collector explosion safety elements may include:
- Heavier doors and side panels.
- Explosion vent panels, which provide pressure relief by blowing out to safely direct the energy of an explosion when pressure inside the collector rises to an unsafe level. These panels must be carefully placed to direct explosive energy away from people.
- A rotary airlock between the collector and the collection bin or hopper. This prevents dust in the hopper from escaping back into the dust collector chamber and providing additional fuel for the explosion.
- An isolation valve to prevent a pressure wave from propagating back into the facility and triggering a dangerous secondary explosion.
Learn more about how we design dust control solutions for abrasive dust across industries: