Cyclone Pre-filters can filter out 90% or more particulate before it reaches downstream filters, significantly reducing fabric filter wear and protecting other industrial dust collection equipment.

The Unique Dust Challenges In Foundries:

Foundries are hot, dusty places—factories where metal castings and other casting services come to life. Castings are produced by melting metal into a liquid, pouring it into molds, and allowing it to solidify. Sand, characterized as an abrasive, is used in metal casting for molding and core making, and silica is typically a key ingredient in molten metal shaping due to its uniform physical characteristics. Unfortunately, silica poses major health risks to humans if inhaled, and so the airborne dust created from sand molds and casting cleanups must be managed properly. The majority of manufactured goods rely in some way on the castings produced by foundries, and like other areas of manufacturing, the dust they produce must be managed via a dust collection system to keep the working environment safe and compliant.

Why Fabric Filters Struggle With Heavy Loading:

Baghouse and cartridge filter collectors are a core piece of many foundry dust collection systems, and are generally very well suited to filter dust from the air in these operations; situated towards the end of the dust collection system, they take on heavy loads of metal, sand, and silica. Depending on the particle size and loading rate of the dust particulate, these fabric filters can suffer from plugging or overloading, inhibiting the airflow of the dust collection system and allowing dust to escape and settle in work areas.

This is a serious concern for foundry personnel because of the increased risk of health hazards and potential explosions.

How Cyclone Pre-filters work:

Enter the cyclone pre-filter. Widely endorsed as a proactive measure for reducing filter loading and increasing dust collection system efficiency, they can be placed upstream of fabric filters to separate out the majority of particulate before it comes in contact with said filters. Cyclones also serve as spark arrestors, increasing the amount of time a spark has to travel before it reaches the filter, and helping to cool down sparks that touch the walls but are not captured—an added bonus for foundry applications.

Cyclones use centrifugal force to capture and remove dust from the airstream, and can often remove 90% or more particulate before it comes in contact with downstream fabric filters. They’re one of the simplest dust collectors available on the market: dirty air enters the cyclone’s inlet and swirls around the separation chamber, where centrifugal forces then force dust out towards the walls.

Once the mixture of air and dust gets down near the hopper, the air changes direction (called vortex reversal) and leaves through the center of the cyclone separation chamber. The solid particles that were concentrated near the wall fall into the hopper and are then removed from the hopper via the airlock.

Any small dust that makes it through the cyclone is then captured by downstream fabric filters, easing the load on the filters themselves and drastically changing the way that dust is managed in the system. Any sparks from the process and the majority of abrasive dust are removed before they can reach the filters, reducing filter cleaning requirements, fire risk, and the amount of compressed air required for cleaning (pulse jet type). Significant savings can be seen if the compressor loading can be downsized for a facility. Ultimately, less dust escapes into the surrounding work areas—lowering the risk of silica damage to employees, and decreasing the risk of explosions or fires.

Aerodyne’s GPC cyclones are compact models with removal capacities comparable to those of traditional cyclones; they differ from traditional cyclones in that they’re shorter, can be configured horizontally, and have an internal ground plate that acts as an integral vortex breaker. Cyclones can be installed in close proximity to areas where dust is generated, and where a larger, traditional cyclone may not fit, which allows the material to be collected and then directly re-entered into the process. This is critical in foundries, where much of the sand and casting materials are recycled heavily. An optional cleanout door can be configured on the cyclone’s backplate for easy access.

GPC Cyclone Specifications:

• proactive measure for reducing filter loading and increasing dust collection system efficiency by filtering majority of particulate ahead of filters
• serves as a spark arrestor
• designed to be installed vertically or horizontally with little effect on collection efficiencies
• utilizes centrifugal force + a ground plate to maximize collection potential
• handles abrasive materials
• eases filter loading to reduce cleaning cycles and increase filter lifetime
• can be installed in close proximity to areas where dust is generated and then directly re-entered into the surrounding processes
• optional “easy clean door”
• 7 sizes under 8 ft³ per NFPA 654
• Ideal for applications with limited space

Dust collection systems perform best in any industry when each of their components is optimized for its role in the system. When fabric filters like baghouses or cartridge collectors take the brunt of heavy dust loading by themselves, it’s a matter of time before efficiency becomes an issue. Implementing a high-efficiency cyclone pre-filter like the GPC shifts the heavy loading burden upstream, often capturing 90% or more of particulate, helping to intercept sparks, and ultimately stabilize airflow before it reaches the filters.

The GPC’s compact footprint and flexibility of installation make it particularly suited for space constrained foundry applications. Improving dust collection system performance doesn’t always translate to replacing the collector itself, but improving the system around the collector by evaluating upstream separation.

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 you are dealing with dust collection system, the most important component is having the correct airflow going through your system so that the dust collection is properly done. While this initially appears to be simple it is the most complex part of a dust collection system. To put it simply, every component from the pickup hoods to the exhaust stack affect the airflow going through the system. And any changes, whether deliberate (ex. changing filters) or accidental (filters plugging) the airflow in the system will be affected. The following explains the different components in the dust collection system and how they affect the airflow.

Pickup Points/ Hoods

Most dust collection system have pickup points/hoods that are used to collect the dust by pulling the air around the location into the dust collection system. The amount of air and the profile of the airflow is based on the hood design. Some hoods are located close to the dust source while other hoods are used to pick up dust across a large area. Using the correct hood is very important when you are designing the dust collector. If you are using a hood designed for pinpoint collection but need to collect over a wide area you will not get the dust collection you are looking for. If you use a wide area hood for pinpoint collection you will be collecting more airflow that is required, thereby increasing the size of you dust collection system.

Ductwork

Now that we have captured the dust in our hoods, we must transport the dust from the hoods to the dust collector. Sometimes you located the dust collector right next to the area you are collecting the dust and sometimes it is located all the way on the other side of the facility. Some dust collectors are dedicated to a single area or process while others handle multiple areas (hoods). All of this requires ductwork to transport the air from one place to another.

Click here to get the complete version of the article: Airflow Through a Dust Collection System.

Dust Collectors

There are many different types of dust collectors that you can use in the system. Each of them have certain strengths and weaknesses. The most common are baghouses, cartridge collectors and wet scrubbers.

Baghouses and cartridge collectors use a filter media that builds up dust and prevents the dust from passing. The filters will be periodically cleaned (by shaking or with compressed air). Over time the dust layer will increase, causing the pressure drop across the filters to increase.

There are multiple types of wet scrubbers used for dust collection. The most common are venturi scrubbers and what can be described as cloud chambers. Cloud chambers use high pressure nozzles to create very small particles to make contact with the dust. While venturi scrubbers force the airflow and water through a small diameter section, forcing the water and dust to contact. Afterward both units have mist eliminators and/or packed towers to collect the water droplet.

Auxiliary Equipment and Accessories

The dust collection system might have auxiliary equipment such as pre-filters, HEPA filters, isolation valves, manifolds and control dampers which could affect the airflow in the system. They all could have pressure drops associated with them, which would need to be added to the system total static pressure for the proper airflow to be achieved by the system.

Exhaust Fan

The exhaust fan is usually the motive power behind the dust collection system. And usually the exhaust fan is a centrifugal blower. One of the characteristics of the centrifugal blower is that the airflow produced by the fan is directly tied to the static pressure produced by the fan at a specific speed. Each centrifugal blower has a performance curve which shows what the airflow and static pressure will be.

The main thing to remember is that if for some reason the pressure drop in the system increases, the airflow through the system will decrease according to the fan performance curve. Often times it is a good idea to install a variable frequency drive (VFD) on the fan so that you can adjust the speed of the fan allotting for changes in filter conditions and other process upsets.

So, to summarize, the dust collection system is sized and designed based on the total airflow going through it. Each of the components has an effect on the whole system, which often times are cumulative. Any modification of the system could affect every other piece of equipment, thereby affecting the total effectiveness of the system. As described above, the dust collection at the pickup points are entirely dependent on the airflow going through them. Any upset, modification, maintenance issue, etc. could affect that airflow, thereby causing the dust collector system not to provide the performance it was designed to do. Therefore, constant monitoring of the airflow in the system is the best way to monitor the dust collection system.

To connect with a member of our engineering team about improving the airflow in your dust collection system, click here, dial 440-543-7400 x 235, or shoot us an email at dc@dustcollectorhq.com.

The post Understanding Airflow Through a Dust Collection System first appeared on Aerodyne Environmental.]]> https://www.dustcollectorhq.com/5-ways-to-go-green-in-dust-collection/ Tue, 30 Jan 2024 00:00:00 +0000 https://www.dustcollectorhq.com/5-ways-to-go-green-in-dust-collection/ 5 Ways to Go Green in Dust Collection. Pulse-on-demand controller. Cyclone pre-filter. Monitor airflow. Aerodyne Vacu-Valve. Clean and reuse filters.

We all know that if we don’t regularly maintain our cars, we will end up having issues in the future. If we forget to change the oil, change the brakes or get a tune up, it will eventually catch up to us. Why do we think our dust collection system is any different? Dust collectors are made of various pieces, all of which have to be operating correctly for the system to operate as desired. Usually, a dust collection system consists of the dust collector, exhaust fan, ductwork, and hoods/pickup points. Additional accessories such as airlocks, controls, instrumentation, and dampers all can affect the operation of the system.

The following questions with quick explanations will help you evaluate your dust collector. If after going through this guide you think your dust collector needs a tune-up, contact a local expert or Aerodyne Environmental and have them come in to help you get your system working properly.

Pickup Points

1. Are the areas near the pickup points dusty? Is there any dust in the air, is it hazy, or is breathing in the area a bit difficult?

2. Are there dust piles around the area? Dust piles and layers of dust can become airborne and if the dust is explosive, it can lead to an explosion causing significant damage and injury.

3. Can you feel airflow being pulled into the hood or pickup point?Often times, dust collection systems will be modified and this could cause a loss of airflow at other areas in the system.

4. Did the dust collection system ever work as expected? Sometimes a dust collection system has never fulfilled expectations. This doesn’t mean that changes can’t be made to get it working better.

Ductwork

1. Does the ductwork have holes? Holes allow air to leak into the system, this will cause less air to be picked up at your hoods and pickup points.

2. Are you plugging up your ductwork? Plugged up ductwork is caused by low air velocities through the ductwork. This will cause low airflow at your hoods and is an explosion danger.

3. Have you added or de-commissioned pickup points on your system? Adding or removing pickup points can cause the system to be out of balance. If you have done this without re-evaluating the whole system, your system may not be operating correctly.

Dust Collector

There are a variety of different dust collectors available—baghouse and cartridge collectors, cyclones, and wet scrubbers. Each one of them has different things to look at. We will only address a few of them here. Contacting a dust collection expert such as Aerodyne Environmental can help you diagnose issues.

Baghouse and Cartridge Collectors

1. When was the last time you changed filters? Some customers have to change filters twice a year, others haven’t changed them since they were installed. Both examples could have issues.

2. What is the pressure drop across your filters? Pressure drops over 6” W.C. usually tells you that you need new filters soon. A low pressure drop can mean that you have holes in your filters or haven’t properly developed a dust cake on the filter.

3. When was the last time you did a maintenance check on your dust collector? If you haven’t done it in the past year or two, it might be time. Filters, tube sheets, diffusers, air valves, manifolds and a variety of other items can all develop issues.

Cyclone

1. Have you checked your cyclone for holes? Cyclones often wear faster than other dust collectors, so a yearly check for pin holes or wearing is always a good idea.

2. Do you have a filter after your cyclone? Since cyclones have lower removal efficiencies than most other dust collectors, if your cyclone doesn’t have a filter afterward, you might want to monitor the emissions regularly to make sure you’re not emitting too much dust.

Wet Scrubbers

1. What is the pressure drop through the wet scrubber? Higher than normal or lower than normal pressure drops always tell you something is happening. Higher pressure drops usually means that dust is building up in the system. Lower pressure drop usually means that less airflow is going through the system.

2. Do you monitor your water usage and the particulate loading of the overflow? The overflow stream of the wet scrubber removes the particulate and the dissolved solids from the system.

3. Are you taxing your water treatment plant? Water treatment is expensive so if you can lower the amount of water going to it, you could save money.

Exhaust Fan

The exhaust fan usually provides all the motive force in a dust collection system; therefore, if the fan isn’t working properly the whole system will be having issues.

1. Is the fan vibrating excessively?
2. Is the fan making more noise than usual?
3. Are the bearings in the fan running hot?

Excessive vibrating and unusual noises can mean that something is wrong with the fan. Damage to the impeller or dust build up on the impeller could cause this. Some fans do get unbalanced over time and could cause the fan to stop working. A bearing running hot could be caused by an issue with the fan or an issue with the bearing. Hot bearings, while unlikely, have been known to cause fires or explosions if all the conditions are right.

Miscellaneous

Other items to check on your dust collection system include dampers, airlocks, controllers and instrumentation. Dampers not operating correctly, or accidently opened/closed can cause operating issues. Airlocks under dust collectors can cause air leakage into the system or prevent dust from leaving the system. Controllers and instrumentation can cause the system to shut down, or provide wrong reading, thereby affecting the operation of the system.

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

To improve efficiency and safety, there is no substitute for an on-site inspection by an experienced expert. Our engineering team is available here to answer any questions you have about improving or evaluating your setup. 

The post Questions to Ask When Evaluating Dust Collection System | Aerodyne first appeared on Aerodyne Environmental.]]> https://www.dustcollectorhq.com/chemical-and-fume-removal-is-wet-scrubbings-cup-of-tea/ Mon, 27 Feb 2023 22:08:00 +0000 https://www.dustcollectorhq.com/chemical-and-fume-removal-is-wet-scrubbings-cup-of-tea/ Chemical and Fume Removal is Wet Scrubbing’s Cup of Tea