Heavy dust loading in the dust collector leads to high maintenance dust collectors.  Since most dust collectors are fabric filters (baghouse, cartridge collectors, shakers, etc.), heavy dust loading will cause/require high frequency of cleaning of the filters.  Most filters are cleaned by injecting high pressure air into the clean side, causing the filters to expand a bit.  This causes dust to fall off the filters.  Filters wear out due to the frequent expanding and contracting.  So the more often you have to clean a filter, the faster the filters will wear out.

Pleated Filters

This is made even worse if the filters are pleated.  Pleated filters have valleys and ridges which increase the surface area available for air to diffuse through the filter.  However, high dust loading can cause the pleated filter valleys to fill up and not properly clean during a cleaning cycle.  This will severely restrict the surface area available for airflow, which will lead to higher velocities through the filters.  A higher velocity increases the chances of dust getting through the filters.  This can cause holes to develop in the filter.  It can also cause dust to plug a pathway through the filter, thereby further restricting airflow.  It can also cause a decrease in removal efficiency.

So if you have high dust loading in your dust collector, it might be beneficial to install a pre-filter to increase filter life and make maintenance much less of a hassle.

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Pre-filtering may reduce operating and maintenance costs by extending bag or filter life and improving removal efficiencies. This video discusses five warning signs that your dust collection system needs a pre-filter.

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

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

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To improve efficiency and safety, there is no substitute for an on-site inspection by an experienced expert. Click below to start with a free 20-minute phone consultation by clicking the button.

To help answer this question, NFPA has released NFPA-652 and 654. A combustible dust is defined as a finely divided combustible particulate solid that presents a flash fire or explosion hazard when suspended in air or the process-specific oxidizing medium over a range of concentrations. Basically, what this means is when the dust is in the air and its concentration is enough to cause a flash fire or propagate a deflagration or explosion if exposed to a spark or heat source, then it’s considered combustible.

Combustible Dust Testing

Unless you know for sure that your dust isn’t combustible, you should send the dust sample to a lab for testing. The lab will provide one of three responses – no reaction, combustible but not propagating, or propagating. 

Usually the lab will initially do a Go/ No-Go test. If the dust doesn’t exhibit combustion, the testing will stop. If it does exhibit combustion, they will then do further tests and provide explosion properties ( Kst and Pmax) of the dust. The Kst tells you how quickly the explosion will propagate, while Pmax tells you the power behind the event.

 

Common Knowledge about Combustible Dust

1. A combustible dust mixed with non-combustible dust may or may not pass the go / no-go test; therefore, if you have both in a mixture, get a test.
2. Material that may not burn can still be combustible as a dust, unless you know for sure, getting a test is the safe bet.
3. If you have made a process change that changes the composition, relative concentrations, etc. of the dust, then the combustibility of the dust may have changed and a new test should be done.
4. If you have combustible dust in your facility, then a hazard analysis of the area must be done every five years.

 

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Dust Collector FAQ Volume 1

To make life easier, we have put together some common questions we get asked along with answers and explanations. Have a look.

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

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To improve efficiency and safety, there is no substitute for an on-site inspection by an experienced expert. Click below to start with a free 20-minute phone consultation by clicking the button.

As regulations to minimize dust emissions became more stringent, the reliance on filter media became more prevalent.  This means baghouses and cartridge collectors have become the most common dust collectors around. 

Dust Collector Filter

The filters allow air to pass, while dust is captured on the filter surface area.  A filter cake of dust forms, allowing the highest removal efficiency of the filters.  Periodically, the filters will be cleaned to drop dust off the filters/ filter cake, allowing more air through the filters.  The higher the concentration of dust, the faster the filters will require cleaning to keep the pressure drop down.  Every time the filters are cleaned the fabric of the filter wears a bit.  So, if you can minimize the cleaning, then the filters will last longer.

Cyclone Pre-Filter and Dust Collector Filter

Cyclone pre-filters capture a high percentage of the dust before it even gets to the filters; therefore, allowing less clean cycles on the filter media.  Cyclones use centrifugal force to capture dust and droplets and remove them from the airstream.  Unlike filters, the higher the concentration of dust in the airstream, the better the cyclone performs.  Cyclones provide very good removal of larger dust particles, often getting removal efficiencies as high a 99% for 30-40 micron dust particles.  But they do remove lower amounts of smaller particles.  So the cyclone is a perfect companion for dust collection filters as they will remove most of the larger particulate.  This can often be 80-90% of the total dust loading of a system by weight.  The cyclone pre-filter then allows the filters to deal with only the fine dust that gets past the cyclone.  The lower loading of dust on the filters allows the filters to last longer and conserve energy as the cleaning cycle isn’t used as much.

Compact Cyclones

Compact cyclones, such as the Aerodyne GPC, allow cyclone pre-filters to be used in existing facilities where larger (taller) cyclones won’t fit.  The Aerodyne horizontal GPC cyclone provides one of the most compact designs - often ⅓ the height of traditional cyclones.  This can often allow the cyclone to be installed inside or in smaller areas of an existing system.  Traditional cyclones typically require outdoor installation, unless the facility has high ceiling.

So if your filter dust collection system is experiencing operational issues, look into compact cyclone pre-filters as a possible solution before you decide to scrap your current unit and install a new one.

 

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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. 

 

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

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To improve efficiency and safety, there is no substitute for an on-site inspection by an experienced expert. Click below to start with a free 20-minute phone consultation by clicking the button.

 

 

Not only do NFPA regulations require a DHA (Dust Hazard Analysis) to be done on all systems that might have explosive dust, they also require the DHA to be updated every 5 years and whenever the system changes. 

Simple Changes in Documentation

The change can be adding , removing,  or changing equipment or changes in the material going through the system. 

Since a DHA has already been done, the scope of the change is much less.  Using the information in the original DHA, the equipment that is being changed can be analyzed to make sure it complies with NFPA.  This report will then be added to the existing DHA so that a record of change is documented.  Usually the report is considered a mini-DHA or System DHA. 

The mini-DHA or System DHA often can be conducted by a 3^rd party consultant working with the equipment manufacturer.  This usually can be done without a site visit.  Aerodyne offers the Mini-DHA/ System DHA for our cyclone separators.

 

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Are you in compliance with the 2018 version of NFPA 68?

Simply click the button for direct access to the webinar to learn more about how to these recent changes may require modifications to your system.

 

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

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To improve efficiency and safety, there is no substitute for an on-site inspection by an experienced expert. Click below to start with a free 20-minute phone consultation by clicking the button.

 

 

We all know that getting the oil change in our car regularly is important to the car being able to get you around when you need it.  However, your dust collector needs regular maintenance too.  The dust collector system consists of hoods, ductwork, air-material separators (cyclones, baghouse, cartridge collectors, wet scrubbers, etc.), explosion protection equipment, airlocks, instrumentation, and exhaust fans. 

All of these items should be checked at least once a year to make sure they are operating correctly.  The following points briefly describe what each piece of equipment needs:

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1. Hoods

• Visual inspection to make sure they haven’t been damaged during the year.
• Measure airflow velocity to make sure they are collecting the design airflow.
• If a local damper is located by hood for balancing, make sure it is operable and in the correct position.

2. Ductwork

• Visual inspection to make sure no holes have developed.
• Measure air velocity through ductwork to make sure designed airflow is correct.
• If possible, visual inspection of duct internal to make sure dust isn’t building up.

3. Air Material Separators

• Measure pressure drop across the separator to see if it is within parameters.
• Inspect cleaning process (baghouses and cartridge collectors) that they are operating properly (timing, valves opening, air pressure, etc.). See operations and maintenance manual.  Often time, listening to the system will let you know if it is operating correctly.
• Monitor recycle line pressure and overflow in wet scrubbers.
• Visual inspection of vessel walls to be sure there are no holes.

4. Explosion Protection Equipment

• NFPA requires yearly inspection, following the manufactures manual is very important so the explosion protection equipment will protect the facility, equipment, and workers as it was designed.
• Some explosion protection equipment such as chemical suppression should be done by factory trained personnel.

5. Airlocks

• Rotary valves
  • Should be checked to see they are still spinning
  • Bearings should be greased and temperature measured to make sure they aren’t overheating
  • On explosive applications the rotor clearance should be measured to make sure it still complies with NFPA 69.
• Pneumatic valves (slide gates, double flap valves, etc.)
  • Valves should be tested to make sure they are still operating as designed.
  • Air pressure should be measured, to be sure it is still within design parameters.
• Motorized valves (rotary valve, double flap valves, etc.)
  • Bearings should be greased
  • Bearing temperature should be measured to be sure they aren’t overheating
• Trickle valves
  • The sleeve should be inspected to be sure it is still sealing
  • During operation confirm that material is still draining and material hasn’t bridged above it.

6. Instrumentation

• Level gages, pressure gages, VFDs, pH meters, zero speed switches, etc. all have different maintenance requirements.
• Follow the manual of the specific model for maintenance and inspection.

7. Exhaust Fans

• The fan housing should be inspected to make sure no holes are present.
• The voltage and amps should be measured to make sure it is operating at its design condition.
• The bearings should be greased and temperature checked to be sure they aren’t overheating.
• The fan’s vibration should be checked along with checking to see if any abnormal noise is emanating from the fan.

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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. Click below to start with a free 20-minute phone consultation by clicking the button.

 

Click below and watch our video to identify five signs that may diagnose a sluggish system so that you can return your system to full efficiency.

 

OSHA is issuing citations and fines to companies with unsafe combustible dust hazards, using their general duty clause and NFPA 652: Standard on the Fundamentals of Combustible Dust as a guideline. Any industrial facility that creates dusts or uses powders was mandated by NFPA 652 to complete a Dust Hazard Analysis by September, 2020 to identify the presence of combustible dusts and establish a plan for eliminating or mitigating potential risks associated with these dusts in their facilities. The DHA is essentially the framework around which NFPA 652 is built, and the starting point for getting a facility into compliance with the standard as a whole.

Dust Hazard Analysis (DHA) Complexity

The complexity of performing a DHA varies with the complexity of the facilities and processes being analyzed.  For instance, a small wood cabinet making shop with a limited number of dust generating machines will present a less daunting task than a large scale manufacturing facility that use powdered raw materials and performs cutting and grinding of its finished product. It should also be noted that performing a DHA should not be viewed as a “one and done” procedure that is completed and forgotten. As new processes or raw materials that have the potential for impacting a facility’s combustible dust profile are introduced in the facility, the DHA needs to be modified to incorporate these changes accordingly.

Dust Hazard Analysis (DHA) Preparation

Preparation for a Dust Hazard Analysis can also be incorporated into a more comprehensive review of a facility’s dust collection system that examines overall system design, efficiency, and safety. Aerodyne Environmental’s Dust Efficiency Clinic offers dust collection system evaluation services that do just that. An Aerodyne dust collection specialist will review a facility’s equipment, installation, controls, and protective devices with an eye toward improving overall system performance, decreasing maintenance costs, prolonging equipment life, and improving safety and regulatory compliance.

Dust Hazard Analysis (DHA) Report

At the end of the system review, a report is generated that summarizes the existing state of the dust collection system and offers targeted suggestions for areas that can be improved. This valuable service offers facility and plant managers outside expertise in boosting the performance and safety of their systems, and is a logical first step in preparation for a DHA.

To learn more about Aerodyne’s Dust Efficiency Clinic consulting services, call Dan Navicky at (440) 543-7400 or tollfree at (800) 358-7546, or email dc@dustcollectorhq.com.

 

The most basic reason to install dust collectors is because the EPA, OSHA or other regulatory agency requires you to.  However there are other reasons to install a dust collector even if you aren’t required to.

1. Health and safety
   • Dust can cause health issues, even if the material isn’t a carcinogen or sub-micron. Dusty air can cause issues breathing, allergies, etc.  All of this can cause operators to be sick more often or want a new job.  This can cause increased operating expenses and less efficiency as you have to cover for absences or have to train a replacement.   Small local dust collectors can help clean the air around operators.
   • Some dust is explosive, and the regulatory agencies are requiring that you test the dust to make sure it isn’t. Even if they haven’t gotten around to it yet, a fire or explosion will cause property damage and possibly injury to employees.
2. Maintenance – Dust will get into mechanical equipment and cause increased wear on them. This increases the maintenance on the equipment, lower productivity and increase operational expenses.  Installing a local dust collector can minimize the dust getting to the surrounding equipment, thereby extending their life.  While there are many factors that affect when equipment needs maintenance, minimizing dust in the air will definitely help extend the time between maintenance.
3. Recycling of material – Local dust collection can help capture product / raw material dust before it is contaminated by other material. This dust can then be reused or recycled, thereby lowering the cost of your process.  Cyclonic dust collectors are especially good at collecting un-contaminated material since they have no filters to retain dusts and can be cleaned out.
4. Environmental responsibility – Local dust collection will help you keep fugitive dust from escaping the building and into the environment. While rain and wind often deposit dust back on the ground, the more dust escaping will cause the air to be dirtier. This could cause smell or dust clouds that neighbors will dislike.  Beyond being a good direct neighbor, you may just have a goal to be a better inhabitant on the earth.
5. Higher morale – A cleaner, healthier environment will help your employees be happier at work. If they aren’t irritated from dusty air, there is a better chance they will enjoy work better and be more productive.  This will allow you to produce more at a lower cost.  And the company will make more money allowing the employees to get better raises.

To learn more about which dust collector, please contact our experts at 440-543-7400 or click on the button below to get our Whitepaper: 4 Potential Dangers to Collectors! How Cyclone Pre-Filters Can Help!

 

 

The airflow in a dust collection system is extremely important, since the air collected at the hoods is removing the dust from the affected areas.  This air is then sent to the dust collector to remove the dust from it.  While it is always desirable to use the least amount of air as possible in your dust collection system, you must have enough air so that it is actually doing the job it is meant to.   If not enough air is going through the system, you will not capture all the dust from the pickup areas, thereby allowing dust to escape into the facility, cause health / nuisance issues and/or fire hazards.  If the airflow is too high, you could be picking up product/ raw materials, wasting energy and increasing maintenance issues.

There are many reasons that the airflow through a dust collection system can change.  A few of them include:

• Environmental changes – temperature, humidity, etc.
• Changes in the system – such as opening/ closing dampers, dust buildup in the ductwork, damage to the ductwork and/or hoods.
• Dust collection issues – such a plugged filters, old filters, holes in the filter, etc.
• Damage to the exhaust fan – such as bearings, damaged impellers, etc.

Unlike liquids, there is no easy and inexpensive way to monitor airflow in a dust collection system.  The most common way is to periodically manually measure the airflow by inserting a pitot tube in the ductwork and measuring the air velocity.  The airflow is then calculated.

One option to monitor your airflow is to install a cyclone pre-filter ahead of the filters.  A cyclone’s pressure drop increases as the airflow increases in them.  Usually the manufacturer of the cyclone can provide a curve, showing the relationship between the pressure drop and the airflow.  So if you monitor the pressure drop through the cyclone, you will notice if the airflow suddenly increases or decreases.  And if the pressure drop drifts too far from a certain pressure drop you will know to troubleshoot the system.

To learn more about the different types of Dust Collection methods,  please contact our experts at 440-543-7400 or click on the button below to get our whitepaper: Top 5 Questions To Ask When Considering A Cyclone Dust Collector.

 

 

Dry dust collectors and humidity don’t react well together.  Baghouses and cartridge collectors operate by having dirty (dusty) air enter the housing.  Multiple filters (bags or cartridges) are located in the housing.  The air travels through the filter and then exits the dust collector.  The filters are a mesh of fibers that allow air to travel through small holes, while dust is too large to pass.  The dust builds up a layer (dust cake), further limiting the subsequent dust’s ability to pass through while allowing the air to pass.  From time to time the dust collector will clean the filters by shaking them or using compressed air to expand them.  This causes the outer layer of the dust cake to fall off.

Humidity can cause problems in the process described above.  Humidity is a way to express the amount of water in the air, (the higher the humidity, the higher the amount of water in the air).  When high humidity air enters a dust collector with fabric filters, there is a chance that the water vapor will condense and create water droplets or the dust on the filters will absorb the water as the airflow passes through.  Many dusts change their physical properties when the water content increases.  Some become sticky, some become hard like concrete, etc.  When this happens to the dust cake, it affects the ability of the air to pass through and the ability of the dust to fall off during cleaning.

When dust becomes sticky, it will adhere to neighboring dust particles and not want to fall during cleaning.  Dust that becomes hard (like concrete) will prevent air from passing through.  When one of these issues develop in a dust collector the pressure drop across the dust collector will increase.  Over time, an increased pressure drop will lower the airflow being pulled through the system.  This will decrease the airflow being picked up at hoods, therefore lowering dust collection at where operators are located.

Humidity can also be introduced in the dust collector in the compressed air.  When air is compressed, the temperature of the air increases, thereby increasing the water content of the air.  The compressed air is at its saturation point.  As the air moves through the line, it cools, thereby condensing water in the system.  If additional drying technology isn’t installed, the compressed air will have water droplets in it as it is used in the dust collectors.  This will cause the filter cake to wet and cause issues as described above.  This is why it is important to dry compressed air when dealing with dust that is affected by water.

However, sometimes no matter how you treat your compressed air, you continue to have issues.  This could be because the airline travels outside and in winter time it gets very cold. It could be because you are located near a large body of water, and humidity is high.  One way to minimize the effect on your dust collector is to minimize the dust getting to your dust collector.  Cyclone pre-filters are ideal for these applications.  Cyclones collect dust and water droplets using centrifugal motion.  This means they aren’t affected by the changes to the dust as a filter is.  Cyclone pre-filters can often remove up to 80% of the dust before a dust collector with filters.  This means you can lower the number of water droplets going into your dust collector and minimize the cleaning required, thereby not getting as much water from the compressed air system. 

To learn more about the different types of Dust Collection methods,  please contact our experts at 440-543-7400 or click on the button below to get our whitepaper, Top 5 Reasons to Use a Cyclone as a Pre-Filter.