Identifying any dust hazards starts with a DHA, which should be conducted in all areas or systems that create dust. A DHA is an extensive report that lays out the requirements for a dust collection system to be protected from explosions. Essentially, will the dust in an environment explode, how bad might it be, and how do we remove factors that contribute to the likelihood of an explosion? Dust testing is also a critical piece of this, because combustible dust is handled differently than non-combustible dust.

How Aerodyne Cyclones Simplify Explosion Protection Requirements

At Aerodyne, we design cyclones for explosive applications that take NFPA specifications into account and make compliance with DHAs easier.  For example, Aerodyne offers multiple cyclones smaller than 8ft3, and when an explosion vent is required, the vent will be located outside the separation chamber, minimizing dust buildup and erosion.

The following are required for combustible/explosive applications, where the goal is to implement equipment and practices that reduce the likelihood of an explosion:

• Explosion vents or chemical suppression*
• Rotary valve, NFPA 68 to prevent explosion from traveling
• No return valve (NRV) to prevent explosion from traveling back up ductwork and into the work area

* Aerodyne has six (6) sizes that are smaller than 8ft3. Depending on the application, these may or may not require explosion venting or chemical suppression.

When it’s apparent that an application deals with explosive dust, our engineers typically lean on the Horizontal GPC (shown in the attached infographic). An explosive vent can be attached to the cyclone to help contain loose dust that presents combustion risks. The Horizontal GPC offers a compact size (may not need to vent if under 8ft3), helps protect vents from dust (horizontal design), and its locality in the system can help keep the majority of dust from getting to the baghouse, preventing buildup in the ductwork.

Aerodyne’s cyclones ensure that the explosion vent can be installed outside the separation chamber and above the hopper, where the vents are significantly less likely to become overrun by dust or wear out prematurely, causing issues. Additionally, because our cyclones are more compact than traditional cyclones, they require smaller vents.

Additional benefits of the GPC for non-combustible applications:

• Increase filter life
• Allow reused of material collected
• Lower compressed air usage for filter cleaning

If you have concerns about combustible dust in your operation, we strongly encourage you to evaluate your dust collection system with a DHA. Although DHAs are not something we offer directly, we offer evaluations that can serve as a DHA precursor that can point you in the right direction. Combustible dust is a scary reality, but it is manageable, and explosions are preventable.

Have a question or interested in a free consultation by one of our reps? Call us at 440-543-7400 to start the conversation.

Frequent wear, unexpected breakdowns, clogging, air leakage, and ongoing maintenance demands can quickly turn a necessary component into a major operational headache — especially in abrasive applications like mining, foundries, cement processing, metalworking, and bulk material handling.

When rotary valves fail, the consequences extend far beyond the valve itself. Downtime increases, manpower gets redirected to emergency repairs, energy efficiency suffers, and production interruptions become more common.

The Problem with Traditional Rotary Valves

Traditional rotary airlock valves rely on multiple moving components to operate effectively. Over time, these moving parts are exposed to abrasive dust, pressure fluctuations, contamination, and material buildup.

In demanding environments, this often leads to:

• Frequent wear and tear
• Material clogging and jamming
• Seal failures and air leakage
• Increased maintenance labor
• Unexpected downtime
• Lost product and reduced efficiency
• Higher replacement and repair costs

The harsher the application, the faster these problems can escalate.

Mining operations, for example, frequently handle abrasive dust and particulate that accelerate component wear. Maintenance teams may find themselves constantly rebuilding or replacing valves just to keep systems running.

As labor shortages and maintenance costs continue to rise, many facilities are looking for ways to simplify operations and reduce unnecessary maintenance demands.

As a result, the real question becomes:

Isn’t there a simpler, lower-maintenance alternative?

A Different Approach to Dust Collection Discharge

Instead of relying on rotating mechanical components, Aerodyne’s Vacu-Valve offers a simpler way to discharge material from dust collection systems.

The Vacu-Valve is designed with:

• No moving metal parts
• No motors
• No lubrication requirements
• No external controls
• No power supply requirements

At the core of the design is an engineered rubber sleeve that remains closed under negative pressure within the dust collection system.

As collected material builds above the valve, the weight forces the sleeve open, allowing material to discharge from the hopper. Once the material is released, the sleeve automatically closes again. This simple operating principle eliminates many of the common maintenance and wear issues associated with traditional rotary valves.

Simplicity Matters in Industrial Environments

In industrial operations, simplicity often translates directly into reliability—think Occam’s razor.

By eliminating rotating components and complicated mechanical assemblies, facilities can significantly reduce:

• Maintenance frequency
• Downtime events
• Wear-related failures
• Spare parts inventory
• Energy consumption

This can free maintenance personnel to focus on higher-value operational priorities instead of constantly servicing problematic rotary valves. For abrasive dust applications, the benefits can be especially significant.

Designed for Challenging Applications

The Vacu-Valve is commonly used in industries where dust collection systems face difficult operating conditions, including:

• Mining
• Foundries
• Cement
• Wood processing
• Bulk powder handling
• Industrial manufacturing

Because the valve operates without motors or complex mechanical systems, it can provide a more economical and lower-maintenance alternative for many dust collection applications.

Reducing Downtime and Operating Costs

Every hour spent repairing or replacing rotary valves is time and labor that could be spent elsewhere. By transitioning to a simpler discharge solution, facilities may be able to reduce maintenance demands while improving overall dust collection system performance.

In some operations, the savings in labor, downtime, replacement parts, and maintenance costs can add up to thousands of dollars annually!

Finding the Right Solution for Your Operation

Not every dust collection system has the same operational requirements. Factors like material type, airflow conditions, dust characteristics, and discharge rates all play a role in determining the best solution. Aerodyne engineers work closely with facilities to evaluate whether a Vacu-Valve is the right fit for the application.

For operations struggling with constant rotary valve maintenance, exploring a simpler alternative may be one of the most effective ways to improve reliability, reduce downtime, and lower long-term operating costs.

Our engineering team is available to provide product recommendations, testing services, and installation support. The best solutions don’t have to be complex, and a conversation is the first step towards better dust collection and material handling– click here to get started.

Multiple factors must be evaluated to ensure the cyclone performs properly for the specific application. An undersized or improperly designed cyclone can increase pressure drop, reduce airflow, and create ongoing maintenance issues.

Here are the key factors that should be considered when sizing a cyclone dust collector.

Airflow Requirements

The first and most important consideration is airflow.

Cyclone dust collectors are directly sized based on the amount of air moving through the system. The greater the airflow, the larger the cyclone required to properly separate dust particles from the air stream.

Without accurate airflow information, selecting the correct cyclone becomes difficult. An improperly sized cyclone may not achieve the desired dust collection efficiency or may create excessive pressure drop within the system.

Because airflow has such a major impact on cyclone performance, it is typically the starting point for cyclone sizing.

Temperature and Pressure Conditions

Airflow volume changes based on temperature and pressure according to the ideal gas law. Because of this, cyclone sizing should always be based on ACFM (Actual Cubic Feet per Minute), not SCFM (Standard Cubic Feet per Minute).

SCFM assumes airflow at standard conditions of 70°F and one atmosphere of pressure. However, actual operating conditions are often much different.

If SCFM values are used without converting to ACFM, the cyclone may end up undersized. This can significantly increase pressure drop and reduce airflow through the system, potentially affecting the performance of the entire dust collection process.

Accurate operating temperature and pressure information are essential for proper cyclone selection.

Dust Characteristics

The type of dust being collected also plays a major role in cyclone design and sizing.

Several questions should be considered:

• Is the dust explosive?
• What removal efficiency is required?
• Is the dust abrasive?
• Is the dust sticky?
• Does the material tend to bridge or clump together?

Different dust characteristics may require specialized cyclone designs or modifications. For example, materials that bridge may require specially designed hoppers to prevent buildup and plugging.

Highly abrasive materials may also require wear-resistant materials or internal liners to extend equipment life.

Installation Location and Space Limitations

The installation environment can strongly influence the type and size of cyclone selected.

Important considerations include:

• Indoor or outdoor installation
• Available floor space
• Height restrictions
• Access for maintenance
• Vertical versus horizontal cyclone orientation

In some facilities, a standard vertical cyclone may not fit due to ceiling limitations, making a horizontal cyclone a better solution.

The cyclone’s role within the system is also important. Some cyclones are used as pre-filters ahead of another dust collector, while others serve as the final dust collection stage.

Understanding the installation requirements early helps prevent costly redesigns later.

Fan Capacity and Static Pressure

For existing dust collection systems, available fan static pressure is extremely important.

The system fan must be capable of overcoming the cyclone’s pressure drop while still maintaining the required airflow throughout the system.

If the fan does not have enough available static pressure, airflow can decrease significantly, reducing overall dust collection performance.

In some situations, correcting the issue may require:

• Modifying the existing fan
• Replacing the fan
• Selecting a larger cyclone with lower pressure drop characteristics

Evaluating fan performance before cyclone selection helps avoid system airflow problems after installation.

Material of Construction

The cyclone’s material of construction must be compatible with the operating environment and the material being collected.

Common materials include:

• Carbon steel
• Stainless steel

However, some applications may require specialty alloys, abrasion-resistant materials, or protective coatings to prevent corrosion and extend cyclone life.

Both internal and external coatings may be used depending on the application conditions.

Choosing the correct material of construction helps improve durability, reduce maintenance, and increase equipment lifespan.

Special Design Considerations

Some applications require additional custom features beyond standard cyclone sizing.

Examples include:

• Quick-access doors for frequent cleaning
• Special weld requirements
• Polished or sanitary finishes
• Custom discharge designs
• High-temperature construction

These special considerations can affect both the cyclone design and overall system performance.

Selecting the Right Cyclone for Your Application

Proper cyclone sizing requires more than simply matching airflow numbers. Factors such as temperature, pressure, dust characteristics, installation constraints, fan performance, and construction materials all influence how well the cyclone will perform in real-world conditions.

Carefully evaluating these variables helps ensure:

• Improved dust removal efficiency
• Reduced pressure drop issues
• Better airflow performance
• Longer equipment life
• Lower maintenance requirements

A properly sized cyclone dust collector can significantly improve the reliability and efficiency of an industrial dust collection system for years to come. To speak with our applications engineer about improving your process, dial 440-543-7400 x 235, or by email at dc@dustcollectorhq.com. For all other inquiries, click here.

For more dust collection and material handling literature, visit the library tab on our website at www.dustcollectorhq.com.

When designing a dust collection system, the static pressure required of the system is extremely important.  The reason is because the exhaust fan must be able to pull the design airflow at the design static pressure in order to get the design performance.  Usually the higher the static pressure is the greater power is required by the fan at a constant airflow.  This means, dust collector system designers usually try to keep the total static pressure low, in order to go with a smaller fan that costs less to operate.

Cyclones Pressure Drop

However, when it comes to cyclones, this is not always the best policy.  A cyclones pressure drop is based on the amount of air going through it.  So a 24” diameter cyclone might have a 3” pressure drop at 1500 CFM and a 5.5” pressure drop at 2000 CFM.  So a smaller cyclone can handle a higher airflow at a higher pressure drop.  This would lower the fabrication cost of the cyclone, and allow it to fit in a more confine space, but have a higher operational cost (more HP required).

Higher Pressure Drop

But using a smaller cyclone also has another benefit, the higher your pressure drop, the more efficient the cyclone will be.  This increase in removal efficiency usually will not allow you to use a cyclone only for dust control, but it will help remove smaller particulate before your primary filter.  This will allow you to capture more material before contamination, lower the loading on your filters, and decrease utility usage (water or plant air).

So when you are designing a dust collection system, don’t look for the cyclone with the lowest pressure drop, but look at all the aspects that affect the system.  Will a smaller cyclone fit better?  Will higher removal efficiency in the cyclone be beneficial to the main dust collector?

How the Aerodyne SplitStream Cyclone Works

The SplitStream Cyclone Collector is designed for dust collection systems where tough dust like abrasive, sticky, fibrous, hygroscopic or granular persist. Configured horizontally or vertically, the cyclone’s low-profile design is perfect for mounting in space-restricted areas.

5 Signs Your Dust Collection System Needs Maintenance

Is your dust collection system working at peak efficiency? A quick, do-it-yourself examination may identify symptoms that your system needs a check-up.

Interested in more dust collection literature? Visit our resource library on the website’s main page. If you’d like to speak directly with a member of our engineering team about your application, click here.

Part 1: Airflow and Pressure Drop

The most basic (and important) thing that affects the sizing of a cyclone is the airflow the cyclone will see.  Cyclones are a mechanical separator without any moving parts.  They are designed in such a way that the more air you put through the cyclone the greater the pressure drop the air will experience going through the cyclone.  To understand this better, a quick review of how a cyclone works will be beneficial. 

Air enters a cyclone near the top of the cyclone.  The inlet is designed so the air will rotate around the walls of the cyclone heading down towards the hopper.  This creates centrifugal forces which send the heavier, larger particles out towards the walls.  Once the air gets down to the hopper, the air goes through a process called vortex reversal.  This means the air turns 180° and goes up through the middle of the cyclone.  The air outlet is located on top of the cyclone.  Often times, the air inlet of the cyclone is located on the tangential, while the cyclone outlet pipe helps form the centrifugal motion.

The greater the airflow through a cyclone the higher the pressure drop the cyclone will have.  So a cyclone will have different pressure drops for different airflows through it.  The pressure drop is not dependent on material loading or cleaning cycles.  The chart shows the pressure drop an Aerodyne GPC-24 will have at a variety of airflows.

When picking a cyclone for your application, you will have to figure out what pressure drop you want through the cyclone.  With a lower pressure, you will have a smaller fan and larger cyclone.  Smaller fans will have lower initial and operational costs while larger cyclones have greater initial costs.

5 Signs Your Dust Collection System Needs a Pre-Filter

Watch the video from the Dust Efficiency Clinic discusses how using a pre-filter will optimize your dust collection system.

If you prefer this valuable information in white paper form, get our whitepaper, Top 5 Reasons to Use a Cyclone as a Pre-filter.

To learn more about the right dust collection solutions for your application, please contact our experts at 440-543-7400 or through here. 

For many years, pulse-jet baghouses were cleaned by simple timers.  The timers would start the cleaning cycle every so many minutes.  You would be able to change how often your filters are cleaned by changing the time between each cleaning.  This design makes sure that the filters are cleaned regularly, whether they need to be cleaned or not.  The main issue with this is that every time a filter is cleaned, it increases the chances of it failing.  Filters are cleaned by pulsing high pressure air into the filter.  This expands the filter, which causes the top layers of dust to fall off.  But that expansion can also cause holes or rips in the filters.

Pulse-On-Demand Controller

So it would be beneficial to minimize the cleaning of the filters to only when it’s needed.  The pulse-on-demand controller does just this.  It measures the pressure drop across the filters.  When the pressure drop gets over a certain amount, it will begin the cleaning process.  Many of these controllers also have “bag break” technology, which will tell you when one of the filters has a hole.  You will then be able to replace the filters only when they are needed.  Some controllers can even isolate the row where the broken bag is located, so you won’t have to replace all the filters.

Installing a Clean-on-Demand controller, “bag break” technology, and cyclone pre-filters (Check out other Aerodyne blogs for more info) can help you decrease the maintenance on your filters, extend filter life, and lower operating costs (less air usage).

To learn more about which dust collector, please contact our experts at 440-543-7400 or visit our website: www.dustcollectorhq.com.

To improve efficiency and safety, there is no substitute for an on-site inspection by an experienced expert. Talk to a member of our engineering team here. 

Filters are cleaned by blowing compressed air into the filter. If the filter is a bag (in a baghouse) then the filter has a metal cage for support. The compressed air expands the bag slightly moving it away from the cage. This dislodges the top layer of dust on the filters allowing that dust to fall into the hopper below. If the filters are cartridges, the support is an integral plastic housing. The compress air still expands the filters, dislodging the top layer of dust.

Every time the filter is expanded it is wearing out.  Over time, a hole can develop and expand enough to let dirty air through the filter.  Or the filter can get caught up on the cage and rip, thereby bypassing the filter.

The best way to minimize this issue is to perform baghouse filter cleaning only when required. Manual or adjustable timers can be used, but without constant monitoring, they will either clean too often or not enough.  A clean on demand controller is best for a baghouse.  It uses a differential pressure transmitter to monitor the pressure drop across the filters.  When the pressure drop is high enough, it will initiate cleaning until the pressure drop is lowered below a certain level.  Depending on the model of controller you have, you can also monitor the unit for broken bags and inoperative air valves.  The other benefit is that by cleaning only when required, you are saving on compressed air usage.

The main drawback of clean on demand controllers is when the bags are plugging up, you begin cleaning more often.  And if you are not properly monitoring the situation, they will begin continuously cleaning.  This happens when the bags are plugged up and no matter how much cleaning the pressure drop will not fall below the shut off pressure.

When selecting your dust collector controller, remember that effective baghouse filter cleaning means avoiding both over-cleaning and under-cleaning your baghouse filters.

So when picking out your dust collector controller, remember that you don’t want to clean your bags too much, but you don’t want to under clean them too.

There’s no substitute for an onsite inspection by an experienced expert to increase the efficiency and safety of your dust collection system. Our engineering team is available to answer any questions you have about your application. To fill out our contact form, click here.

Timers and Clean-On-Demand

The two main controllers used are timers and clean on demand.  A timer is a simple controller which will turn on the cleaning cycle at a set time, such as every 5 minutes.  The timer can be changed, and a manual clean is usually available.  While the initial cost of this timer is less, it can end up wasting a lot of money if the timer is cleaning more often than required.  If the timer isn’t cleaning enough, then the dust collector is not operating at its optimal.  The other controller is clean on demand.  This controller uses a differential pressure transmitter to monitor the pressure drop across the bag.  When the pressure drop gets to a certain point, it will begin cleaning the bags until the pressure drop is lowered to a certain point.  This can save you a lot of money by minimizing the compressed air required.  However, if your bags are plugged, the cleaning can be continuous as the pressure drop will never fall below the cutoff point.

Reasons of High Pressure Drop On Filters

Filters will have high pressure drops due to a variety of reasons or even a combination of reasons working together.  These include heavy dust loading, wet or humid conditions, worn diffusers, humid compressed air, improper cleaning, and old filters.

• Heavy dust loading will plug filters faster than lower dust loadings. The faster dust covers the filters, the more the cleaning is required.  However, every cleaning doesn’t get 100% removal so over time the dust layer will get thicker and thicker; thereby, increasing the pressure drop.
• Wet or humid dust can cause pre-mature plugging. This is because when the dust gets wet it can form a mud.  This could prevent air from passing through, thereby increasing the pressure drop.  If the dust is hygroscopic and/or if the filter is pleated, the filter can plug up even faster.
• Dirty air entering a baghouse usually goes through a diverter, which directs the air evenly to each bag. Many times the diverter is some metal shape.  Over time, abrasive dust will wear away the diffuser changing the airflow.  This usually means some filters will get heavier dust loadings than others.  The filters getting the heavier dust loading will then plug faster, increasing the pressure drop through the system.
• Humid compressed air can cause major issues with certain dusts. If the dust is hygroscopic, then adding moisture to the system can cause problems.  Some dust becomes a mud while others form a concrete like substance.  Since the humidity is coming from the cleaning air, the humidity is meeting the dust in the filter holes, thereby plugging them up faster, and making it even harder for them to be cleaned.
• If the cleaning system isn’t operating properly, the bags will not clean effectively. This could be anything from stuck/broken air valves, misaligned venturi, bags stuck on cages, or too low compressed air.  Since the bags are cleaned by an expansion of the bag and losing the dust layer, if air isn’t delivered correctly, the bag may not fully inflate and not fully clean.  So any obstruction or barrier to full inflation would cause premature plugging.
• As mentioned above, over time all filters will plug up.

The best way to keep your dust collector working properly is to have a professional maintenance crew inspect and maintain your dust collectors.  Not only does this open your maintenance staff for other work, it allows them to use their experience to keep your baghouse operating at peak performance.

To learn more about finding the right dust collector for your application, please contact our experts at 440-543-7400 or visit our website: www.dustcollectorhq.com.

If the dust collector isn’t properly maintained, the system will gradually lose efficiency over time, until it isn’t performing to the optimum.  Often, this isn’t even noticed by the operators because it gradually changes.  However, a new worker or outside observer will notice it, since they will see dust building up around the pickup points.  This gradual efficiency loss can be caused by dust collector issues, dust buildup in the ductwork, or fan issues.  It could also be caused by modifications of the dust collector system after it was installed.

One way to monitor a dust collector system is with pressure drop across the dust collector.  This is a very good way to see if the dust collector is plugging up.  The one issue with this is that if you aren’t constantly monitoring the system, the dust collector could plug up, and a decrease in airflow through it could provide the same pressure drop.  Regular inspections of the dust collector and ductwork should be scheduled to make sure issues are not developing.

Another great way to check your system is to measure the airflow at various parts of your system.  These measurements will tell you if the system is operating correctly.  The reason you want to take multiple measurements is that when you have more than one pickup point, air will travel the path of least resistance.  This means that if one of your pickup points is plugged up, more airflow might be coming from the other pickup points, and the total airflow at the dust collector might be nearly the design amount.  However, the plugged up pickup point isn’t operating as designed.

Often times, dust collection systems are designed for a specific function, then over time, it is changed by either adding or removing pickup points.  This could seriously affect the performance of a dust collector system.  If the changes are made without running calculations, pickup point airflows could change, which could allow dust accumulation around certain areas.

If you have modified your dust collection system in the past, it is a good idea to run some calculations on your system, to make sure it is operating correctly.  If you are planning on modifying your system, design the change so that your system will operate correctly.  If you don’t know if your system has been modified and/or you have dust buildup, check the system design.  If you don’t have the time or expertise for this, consultants can be hired to help you out.