A significant benefit of using a cyclonic dust collector as a pre-filter for baghouses or cartridge collectors is increasing removal efficiency. A cyclone removes all types and particle sizes of dust. At larger particle size, dust collection is nearly 100% but with smaller size (ex. sub-micron) particulate the collection can typically less than 5%.

Filter Cleaning Cycle

Filters such as bags and cartridge collectors get their high removal efficiencies by building up a dust layer over the filter.  This dust layer allows air to pass through it and the filter while preventing dust particles from passing.  As the dust layers build up, it becomes harder and harder for air to pass through, hence the increase in the pressure drop of the collector.  The filter cleaning cycle is used to remove the top layers of this dust layer; thereby allowing air to pass through easier.

Particles in the Dust Loading

When large particles are in the dust loading, they will block more passages of the air.  However, the layer may not be as uniform, thereby allowing high velocity channels that will allow the smaller particles to pass, with enough velocity to get through the filters.   If the dust loading particle sizes are more equal (smaller) then the dust layer is more uniform, letting less small particles through, thereby increasing the removal efficiency. 

Cyclone Pre-Filter

The installation of a cyclone pre-filter removes the largest particles, allowing only the smallest to pass.  This allows for a more uniform dust layer, thereby increasing the removal efficiency of the filters.

 

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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. 

 

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.

 

 

Dust collection systems require the proper airflow to operate correctly.  Without the correct air flow, dust will not be removed from collection points and the collection equipment (baghouse, cartridge collectors, cyclones, etc.) will not operate with maximum efficiency. However, if too much air is being pulled through the system, a variety of issues might ensue, such as product being lost, removal efficiency lowered, utility usage increased.

Conventional Way to Measure Airflow

The normal way to measure airflow is to insert a pitot tube in the ductwork to measure the air velocity in an airstream, and then calculate the velocity (and airflow).  This is a manual process that requires a trained individual.  It is time consuming and to a certain degree an art, since the velocity in a ductwork changes depending how close to the wall you are.

Effective Way to Measure Airflow

Obviously, you cannot walk next to a piece of equipment or meter and check the velocity through the ductwork.  However, if you have a cyclone dust collector you can.  Cyclone pressure drops are based on the airflow through them.  The more air you send through a cyclone, the higher the pressure drop.  Each cyclone design has its own equation to determine pressure drop based on the airflow.  With this equation, you can estimate the airflow based on the pressure drop in your cyclone.

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The GPC Dust Collector is an efficient way to handle your dust collecting needs. Simply click below for direct access to the GPC spec.

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Exhaust Fans: The Motive Force of a Dust Collection System

In this video, Aerodyne discusses how system changes and fan performance affect 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.

The key function of a collector is to remove the maximum volume of dust from the airstream.  Additionally, an important part of the process is keeping the removed dust from re-entraining.

Baghouses and Cartridge Collectors

Baghouses and cartridge collectors collect the dust on the filters and during cleaning, the material is knocked loose and falls to the hopper.  How well the material falls to the hopper is dependent on the dust that is being collected, the can velocity (speed of air between the filters) in the baghouse, and the design of the baghouse.  

Basically, if the dust is very light and/or irregular in shape, then it might not easily fall to the hopper, instead it might float (like a leaf).  This could cause it to be re-entrained in the airflow and go back on the filter.  If the airflow is very high then the can velocity could hold up dust after cleaning, thereby causing re-entrainment of the dust.  The design of the unit can affect re-entrainment as well.  Some units have the dust coming in the unit below and at a rather high speed, which can increase dust re-entrainment.  Others will have the dust entering from the side of the filters, thereby being at a much lower velocity and out of the path of falling dust.

Cyclones

Cyclones use centrifugal force to push the particulate dust outward.  Most cyclones also use tapered walls to concentrate the dust as it gets lower in the cyclone until it falls into the hopper, while the clean air leaves the cyclone through the center.  The point where the air stops traveling down the walls and begins to travel up the center is called vortex reversal.  Depending on dust size, concentrations, and cyclone design, dust can be re-entrained by the clean air leaving the cyclone.

Wet Scrubbers

Wet Scrubbers are very good at low re-entrainment.  This is because when the dust meets a droplet, they become one larger particulate and then fall out of the airstream easier.  Most well designed wet scrubbers have a mist elimination section that will further collect droplets before leaving the collector.

 

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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.

 

 

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.