Where to Spend and Where to Save on Dust Collector Components

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Dust collection cost iceberg

Regardless of your industry, business size, or region, keeping the air clean and your workers safe is a top priority. This is where dust collection systems come into play. They not only protect your employees from harmful carcinogens and health issues, but they keep your equipment running smoothly and your business compliant and out of the crosshairs of regulatory agencies. With those priorities in mind, it’s important to note that selecting the right parts for your dust collector is more than just looking at the price tag. Let’s dive into the art of making smart decisions – knowing where to invest and where to save when it comes to dust collector components.

Don’t Skimp on Filtration Efficiency

Before we get into the nitty-gritty of costs, remember that filter performance is the most crucial element of your dust collection system. Filters are like the guards at the gate of safety, health, and compliance, and their job should never be compromised. When it comes to dust collector filters, it’s about finding the right one for your application. It’s like cooking a good meal – you need the right ingredients. Once you find the right one, you have to make sure to replace them before they fail and damage your system. Read more: How often should filters be changed?

 It is very common for users to look for deals on filters – for example, replacing a high-efficiency nano cartridge filter with a cheaper 80/20 cartridge filter to save on cost. However, in this case the 80/20 cartridge offers roughly half of the filter area of a nano filter of the same size, meaning your system can now handle half of the air flow it was designed for! And the efficiency of the cheaper filter is much less – MERV 11 vs. MERV 15, so there is a good chance that you will be emitting much more dust than expected. Finally, the 80/20 filters will wear out significantly faster than the better filters. So it worth paying more for a better filter with longer life, better efficiency and better performance throughout your system? You bet! The total cost will be lower in the long run (see farther down).

Being Eco-Friendly Matters

Your duty is not only to your workers but also to the environment. In a world of strict rules, your choices should match the limits set for different types of dust. Some dust is just annoying, while others can be harmful. Sometimes, the law requires you to use extra-efficient filters, especially for hazardous dust. Knowing these rules helps you pick the right filter. Learn more about these regulations.

More Than Money: Considering Dust Particles

 Look beyond the cost and consider the characteristics of your dust. Is it fine or coarse? Is it combustible? Is it sticky? These things really matter when choosing the right filter. Some may think that obtaining the right filter is very expensive and may look for cheaper alternatives. Check here why this is a dangerous decision: Why Are My Baghouse Filters So Expensive?

The Real Costs: Total Cost of Ownership (TCO)

As any good supply chain professional knows, the up-front price tag doesn’t tell the whole story. There’s more to cost than just buying the item. TCO is a fancy way to say, “How much does this really cost over time?” It includes energy use, how often you change filters and cages, and other hidden expenses. E.g.: Using electricity costs money. Filters need air to flow through them, and that takes energy. But there are smart ways to save energy, like using special fans that don’t waste electricity. 

Money-Saving Options

One item that perfectly illustrates the difference between short-term cost and long-term savings is the use of VFD (variable frequency drive) fan controllers. A VFD allows the user to run their dust collector fan at a lower or higher rate to manage performance. Rather than simply flipping a switch and running your fan at full speed (think 40kW per hour), the fan motor will run at a lower rate, saving significant energy costs in the long
run. Generally, upgrading your fan controller to include a VFD will cost several thousand dollars, but this cost is easily recouped after a year of running your system more efficiently.

Energy Price Trend

Next Steps: Being a Smart Chooser

Remember, this is more than just a dust collector. It’s about keeping your workers safe, your equipment in shape, and your business running well. So, when you’re thinking about where to spend and where to save, remember that the journey to a better dust collection system goes way beyond just buying stuff. It’s about being smart, safe, and forward-thinking.

 Take a deeper dive into our dust collection blog for more helpful articles and insights. Let’s make your dust collection system the best it can be!

 

 

Contact Us to Speak to One of Our Baghouse Experts.

 

For more baghouse related training and information, be sure to check out our Baghouse Online Training page.

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How Often Should Baghouse Filters Be Changed?

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How Often Should Baghouse Filters be Changed?

One of the most common questions we hear is, “How often do I need to change my baghouse filters?” The most accurate answer is – it depends. However, as that is not the answer you were hoping for, here is a general rule to help you estimate filter life:

In general, baghouse filters have a useful life of 1-3 years.

This is an average range for most filters in the most common applications where the dust load is not extremely heavy, and the gas stream and dust is not hot, abrasive, wet, acidic, etc. All of these factors will affect filter life.

A properly sized dust collector with plenty of filter area, collecting room temperature dust, running one shift, properly maintained, may only need the filters changed every three years. An undersized collector, run continuously for 24 hours per day, collecting an abrasive dust (silica dust, metal shavings, etc.) at elevated temperatures will certainly require filter changes more often, perhaps as often as monthly in some cases.

Why Do Baghouse Filters Need to Be Replaced?

The most common mechanisms for filter failure are:

Broken Baghouse Filter

This bag filter has a hole due to wear.

  • Blinded filters that no longer filter dust
  • Sparks/embers that burn small holes in the filter material.
  • Wear damage caused by the filters rubbing against each other or the metal cages (improperly maintained cages).
  • Temperature spikes that cause the baghouse temperature to exceed the filter design temperature.
  • Chemical attack on the filters.
  • Improperly installed filters.

Any of these reasons for failure result in leakage – dust making it past your filters and into the clean air stream. If the filters fail, dust will be released into the atmosphere or back into your building, depending on your system. This is obviously bad, as it means the dust collector is no longer doing its job.

How do I Know When my Filters Need to be Replaced?

There are a few ways to evaluate your filter condition, and some indicators that your filters need to be changed:

  1. Visual Inspection: Take a look at your filters and look for holes, rips, or signs of dust leakage. Look inside the clean air plenum in your dust collector – if there is any dust present, it is possible that one or more filters are leaking and require replacement.
Baghosue UV Leak Test

UV Leak Test Identifying a Leaking Filter

  1. Visible Emissions: If your filters are working properly dust will be filtered out and only clean air will be visible coming out of the fan exhaust. If there is dust visible, you have a leak.
  2. Differential Pressure: Over time as your filters accumulate dust, your differential pressure gauge will creep upward. When your pulse jet, reverse air, or shaker system activates to clean your system, you should see the DP go down. If your filters are blinded the DP will remain high, meaning the filter cleaning system is no longer effectively clearing dust from your filters – it is time to change your filters. As a general rule, if your DP gauge reads greater than 6 in. WG your filters may be blinded. (Click here to learn more about pressure gauges).
  3. Leak Sensors: Leak sensors are available to detect broken filter bags downstream of the dust collector. A leak test can be used to identify a specific filter that is leaking. (Click here to learn more about broken bag detectors).

 

Have More Filter Questions? Contact Us to Speak to One of Our Baghouse Experts.

 

For more baghouse related training and information, be sure to check out our Baghouse Online Training page.

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How Does a Magnahelic Gauge Measure Baghouse Performance?

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A Primer on Pressure Gauges for Dust Collection Systems

Contents

How Differential Pressure Gauges are Used in Dust Collection Systems
How to Use a Magnahelic (Differential Pressure) Gauge to Measure Dust Collector Performance
     What is the Expected Range of Static Pressure Drop Across a Baghouse?
     Can Static Pressure Drop be “Too Low”?
How to Select a Differential Pressure Gauge
Integrated Differential Pressure Gauges
Magnahelic vs Photohelic Gauges
How are Flow Sensors Used to Measure Dust Collector Performance?
Pressure Gauge Maintenance
Purchasing a Differential Pressure Gauge

How Differential Pressure Gauges are Used in Dust Collection Systems

 

Magnahelic Gauge

Standard 0-15 in WG Magnahelic Differential Pressure Gauge

 

When inspecting or evaluating a dust collector (baghouse, cartridge collector, etc.) or dust collection system, you will see various gauges installed at different locations in the system. These sensors are in place to help you monitor and control the performance of the system. The most common gauges you will find are:

  • Differential pressure gauge: Often referred to as a Magnahelic Gauge (Magnahelic is a specific brand name, but many people refer to all DP gauges as ‘Magnahelics’), a differential pressure gauge is typically installed on or adjacent to the dust collector. It measures pressure the pressure drop across the filters in your dust collector. The gauge consists of two pressure ports that are connected to either side of the filters. As dust accumulates on the filters, the pressure drop across them increases. The differential pressure gauge measures this pressure drop and provides a reading that indicates when the filters need to be cleaned or replaced. This helps to maintain the efficiency of the dust collector and prevent damage to the system. It is also a useful metric to track daily, weekly, and monthly to monitor the health of your filters and filter cleaning system.
  • Static pressure gauge: A static pressure gauge may be installed at various points in the ductwork of a dust collection system to measure the static pressure of the system. By monitoring the static pressure at different points, operators can identify areas of the system that may be causing airflow restrictions or problems with the system. This can help to diagnose issues with the system and optimize its performance. You will also likely see a standard pressure gauge on your compressed air line if using a pulse jet style dust collector.
  • Flow sensor: A flow sensor is typically installed in the ductwork of a dust collection system to measure the airflow rate of the system. The sensor typically consists of a probe that is inserted into the ductwork, and it measures the velocity of the air passing through the duct. By combining this measurement with the cross-sectional area of the duct, the flow sensor can provide an accurate measurement of the airflow rate. This information is useful for optimizing the performance of the system and maintaining a safe working environment for operators. Flow sensors are less common with simple dust collection systems but are an inexpensive way to ensure your airflow stays within range.

How to Use a Magnahelic (Differential Pressure) Gauge to Measure Dust Collector Performance

The static pressure drop measurement is a critical parameter in assessing the performance of a dust collector because it provides real-time information about the condition of the filter and the overall efficiency of the system. As the filter accumulates more dust particles, the static pressure drop increases, which reduces the airflow and negatively impacts the dust collector’s performance.
If you watch the gauge for a few minutes, you will see the differential pressure slowly rise as dust accumulates on the filters. When the pulse jets fire (you will hear the blast of compressed air), you will see the pressure drop as the dust cake is knocked off the filters by a blast of compressed air, allowing more air flow through the filters.
By monitoring the static pressure drop over time, maintenance personnel can determine when it is time to clean or replace the filter to maintain optimal performance. Regular monitoring of the static pressure drop also helps identify any unexpected issues with the dust collector’s design or operation that may be causing excessive filter clogging or decreased airflow.

What is the Expected Range of Static Pressure Drop Across a Baghouse?

The expected range of static pressure drop (also referred to as differential pressure, or “DP”) across a baghouse dust collector can vary depending on several factors, including the type of baghouse, the type of filters used, the airflow rate, and the properties of the dust being collected.
Generally speaking, a static pressure drop of 3-6 inches of water column (WC) is considered normal for a baghouse dust collector. However, the pressure drop can range from as low as 1 inch WC to as high as 10 inches WC or more, depending on the specific operating conditions and the design of the baghouse.
For a cartridge collector, generally a static pressure drop (or “DP”) of 1-4 inches of water column (WC) is considered normal. A DP higher in the 5-6 inches or higher range is a good indicator that the filters are clogged (or “blinded”) and need to be changed. Some manufacturers design their collectors for a higher differential pressure, so check your manual to be sure.

Collector Type Normal DP (differential pressure) Range
Baghouse Collector 3-6 inches WG
Cartridge Collector Or Baghouse with Pleated Filters 1-4 inches WG
Expected Range of Static Pressure Drop Across a Baghouse

Can Static Pressure Drop be “Too Low”?

After a filter change, you will notice that the static pressure drop indicated on your gauge starts very low. You may also notice that the filters do not immediately capture all dust. This is normal. Over time (an hour or so depending on filter type and dust load), the filters will accumulate a “dust cake”, which allows the filters to efficiently capture dust. This is known as “seasoning” the filters. After this seasoning period, you will notice the DP increase to normal operating range.
If you notice a sudden drop in differential pressure, it could be an indicator of a leak or a broken bag or filter. This is another good reason to check your Magnahelic gauges daily, so you gain an understanding for the normal range for your dust collector.
Most issues that affect your dust collection system (full hopper, broken filter, blinded filters, non-functional pulse jet cleaning system, etc.) will be noticeable as an anomaly in the differential pressure gauge reading, so it is very important that your daily maintenance schedule includes a check of the differential pressure gauge.

How to Select a Differential Pressure Gauge

When selecting a static pressure gauge for a dust collector, there are several factors to consider to ensure accurate and reliable measurements:

  • Gauge type: There are different types of static pressure gauges available, including mechanical, electronic, and digital. Mechanical gauges are the most common and are relatively inexpensive, but they can be less accurate than electronic or digital gauges. Electronic and digital gauges offer better accuracy and precision, but they can be more expensive.
  • Pressure range: Choose a gauge that has a pressure range that covers the expected operating range of the dust collector. It is important to ensure that the gauge can accurately measure the expected static pressure drop across the filter. The pressure range is typically indicated on the gauge or in the product specifications. Most dust collectors should have a 1-10 in. WG pressure range.
  • Accuracy: The accuracy of the gauge is an important consideration. A higher accuracy gauge will provide more precise measurements and help ensure that the dust collector is operating at optimal performance. The accuracy of the gauge is typically indicated in the product specifications.
  • Display: Choose a gauge with a clear and easy-to-read display. This is especially important if the gauge will be monitored regularly.
  • Durability: The gauge should be durable enough to withstand the conditions of the environment in which it will be used. For example, if the dust collector operates in a harsh or corrosive environment, choose a gauge that is designed for such conditions or locate the gauge remotely where it can be installed without being exposed to the harsh environment.
  • Installation: Consider how the gauge will be installed in the system. Some gauges require mounting on a panel, while others can be installed directly into a pipe or duct.

Integrated Differential Pressure Gauges

Many dust collector companies including Baghouse.com offer dust collector controllers that include integrated DP gauges. Pulse valve cleaning systems can often be set to “clean on demand”, which means the pulse valve controller senses the differential pressure and only fires the pulse valves when the DP reaches a set value. This is a more efficient mode than simply cleaning on a timer, as it uses compressed air only when needed. Many of these controllers have a digital readout to display the DP value.

Turbo controller with integrated differential pressure sensor

Turbo Controller with Integrated Differential Pressure Sensor

One limitation to controllers with integrated pressure sensors is heat. If your application will expose the controller to temperatures greater than 120F, the heat may cause your controller’s pressure transducers to fail prematurely. In these rare cases, we recommend locating the controller in a remote location that is shielded from extreme heat.

Magnahelic vs Photohelic Gauges

Magnahelic Gauge Installed on a Baghouse

Magnahelic Gauge Installed on a Baghouse

Magnahelic gauges and photohelic gauges are both types of differential pressure gauges commonly used in HVAC and dust collection systems. While both gauges measure the difference in pressure between two points, there are some differences between the two types of gauges.
Magnahelic gauges are mechanical gauges that use a spring-loaded diaphragm to measure pressure differences. The diaphragm is connected to a pointer that moves over a scale to indicate the pressure difference. Magnahelic gauges are rugged, reliable, and relatively inexpensive, but they are not as versatile as photohelic gauges, as they do not provide flow rate readings.
On the other hand, photohelic gauges are electronic gauges that use a light beam and a photodiode to measure pressure differences. The photodiode detects the amount of light that passes through a transparent diaphragm that is deflected by changes in pressure, and the gauge converts the light readings into a pressure reading. In addition to measuring pressure differences, photohelic gauges can also provide flow rate readings by using a built-in flow guide that directs the airflow through the sensing element.
Another significant difference between magnahelic and photohelic gauges is the display. Magnahelic gauges typically have an analog display that shows the pressure difference using a pointer and a scale, while Photohelic gauges have a digital display that shows the pressure and flow rate readings in real-time.
Choosing between a mechanical or photohelic gauge will depend on your budget and your application. If you plan to connect your pressure gauge to a computer system or HMI (human machine interface) in a control room, you will likely select a photohelic gauge which can output the sensor readings via an electric output.

How are Flow Sensors Used to Measure Dust Collector Performance?

A flow sensor is another commonly used instrument to measure the performance of a dust collector. Unlike a static pressure gauge that measures the resistance to airflow caused by the accumulation of dust particles on the filter, a flow sensor measures the actual airflow rate through the dust collector.
The flow sensor is installed in the duct or pipe that carries the air from the dust collector, and it measures the volume of air passing through it per unit time. By measuring the airflow rate, the flow sensor can provide information about the efficiency of the dust collector and identify any problems that may be impacting performance.
Typically flow sensors are connected to a Magnahelic type pressure gauge. The user must correlate the pressure gauge reading to the cross sectional area of the duct to calculate a flow reading. Once this initial math is done, set point for the pressure gage can be established so maintenance staff can check the reading daily/weekly and note if the pressure is outside the expected range, indicating a blockage or leak in the duct, or some other anomaly that needs to be fixed before it causes a major problem.

Pressure Gauge Maintenance

Maintaining your gauges is fairly easy. Once a week, the pressure tubes running to the gauge should be disconnected and cleared out with compressed air to ensure a good reading.


Not sure if your gauge is reading correctly? Disconnect one tube at a time. When the low pressure side is disconnected, your DP reading should jump. When the high pressure side is disconnected, the DP reading should go to zero. If you disconnect a pressure tube and the DP reading doesn’t change, it is likely that one or both of the pressure tubes has as leak or is plugged.

Purchasing a Differential Pressure Gauge

Baghouse.com sells all types of dust collection system parts and components, including differential pressure gauges for all applications.
For pricing, please Contact Us and we will provide you a quote and answer any questions you may have.

CONTACT US TODAY!

For more baghouse related training and information, be sure to check out our Baghouse Online Training page.

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Other Causes of Baghouse Filter Failure

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An image of dust collection filters completely covered in build-up from moisture

The four main reasons why baghouse filters fail prematurely are abrasion, exceeding the maximum operating temperature, chemical attack and fire. All of these can dramatically shorten the the life of a baghouse filter as well as cause serious damage to the baghouse system*. However there are other lesser known causes that can cause premature dust collector filter failure. Let’s review them.

“If the filter system is undersized, then the filters will suffer increased wear…”

Undersized Dust Collector for CFM

It is essential that an industrial baghouse system be carefully engineered and sized to handle the right amount of air flow (CFM) for the application. If the filter system is undersized, then the filters will suffer increased wear.  Additionally, an undersized system will eventually lead to inadequate air flow, poor venting that can damage equipment, higher emissions, loss of reclaimed product and a hazardous work environment.

A dust collector can be undersized in two main ways: (1) by not having enough filters for the airflow, and (2) by having too much airflow through too small of a unit, thus creating high internal can/interstitial velocity.

Sadly, many less reputable sales reps and even some dust collector OEMs often undersize systems in order to undercut their competition on price. Other times, plants have tried to increase system capacity without consulting with an experienced dust collector manufacturer and even up overloading their units.

Wrong Filter Media or Style of Filter  

The choice of baghouse filter media depends on a number of factors, such as temperature, resistance to chemicals, target dust size, physical characteristics, collection efficiency and price. If the choice of fabric is unsuitable for the application required, this can have a dramatic reduction in the lifespan of the filter.

For example, trying to use a low temperature filter fabric such as polyester (max temp 250F – 275F) in a high temperature (300F – 500F) baghouse system will quickly result in filter failure. 

Often, operators must consider more than just the maximum temperature as the mix of temperature, humidity and chemical makeup in the gas stream can cause failures if not accounted for when selecting the media. For example, in many gypsum applications the temperature is not normally very high (under 200F) so polyester media might seem to be a good choice. However, the combination of elevated temperatures and high humidity can cause the gypsum to react with the polyester and cause hydrolysis, which leads to the bag becoming hard and brittle. For this reason many gypsum applications used aramid filters even though the temperature normally would allow for cheaper polyester bags.  

Finally, many suffer problems due to using cartridge filters where a bag filter is more appropriate. Man applications can make good use of cartridge collectors to improve operation and reduce the overall cost of a system. However, we often see people try to use cartridges in applications ill-suited for them such those with irregular-shaped material, sticky materials, or high temps.


An image of a baghouse filter that has hardened from hydrolysis
Picking the right fabric for the right temperature isn’t everything. This is the effect of hydrolysis on an improperly selected baghouse filter.

Bent and Damaged Cages

During regular maintenance or when stored improperly, cages can be bent, damaged, warped and or even corroded. Using baghouse filter cages in this condition will lead to the filters failing prematurely. When a cage is bent or damaged, sharp points can form from broken wires and cracked welds that can physically damage the filter creating tears and holes.  If rust or corrosion is present on the cage, this creates abrasion and leads to tears and holes in the filter. Additionally, bent cages will cause the bags to hit each other or the sides of the housing when they are pulsed creating localized wear spots.

An image of a PTFE filter with two small holes in its fabric
Have you reused rusted or bent baghouse filter cages and then seen holes in your filters like these?

Poor Installation

Improper installation of filter bags can also result in early bag failure and loss of cleaning effectiveness. For top load pulse jets, the most common install errors involve not seating the snap band properly. For a bottom load unit the bag not being folded over the top of the cage properly, poor clamp placement and tightening the clamp too much or too little are all common. 

Additionally, duct design, turning vanes and deflection plates all contribute to uniform gas distribution to all filters. However poor installation of these elements can result in high airflow regions that will abrade the filter bags.  Rough handling such as bending or stepping on the bags during installation or improper tensioning can also cause holes or tears in the bag filters reducing their strength and durability.

Moisture

An image of dust collection filters completely covered in build-up from moisture
Please tell us that you check your baghouse filters enough before letting moisture build up this badly.

Common sources of condensation and moisture in a baghouse are leaking gaskets around the doors and airlocks or upset conditions in the process.  Moisture can weaken the filter media, causing filter leaks or failures, and allow dust to bypass the filters. It can also alter the adhesion characteristics of the dust creating hard-to-clean mud and blinding of the filter. Moisture can also create chemical issues within the baghouse. For example, acid gases mixed with high moisture can cause an acid flash. This is where the acids condense out of the gas stream and damage the filters and housing. 

As discussed in this and the previous article, there are a number of reasons why industrial baghouse filters fail prematurely. Baghouse.com has experience helping many with these and other problems find solutions to get their systems back to peak performance. For more information and to arrange a quote for all your baghouse requirements, please contact us at Baghouse.com

* See article “Top 4 reasons why baghouse filters fail”

Need Help Ordering Baghouse Filters?

Whether you know exactly what you want or could use some help getting the right dust collection filter, we’ll put together a free quote with the perfect filter for you.

Contact Us Today!


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Video: Intro Guide to Sizing and Designing Your Baghouse

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An image of Baghouse expert Dominick DalSanto in front of a camera with the text "Sizing Your Baghouse" displayed in front of him
A video introduction to the Baghouse.com Guide for Sizing and Designing your Dust Collection System

Hi, and welcome to our guide for how to properly size and design your dust collection system.

This guide is going to help you to avoid some of the more common pitfalls we see with sizing a dust collection system. For example, many dust collector OEM’s and sales rep organizations will frequently undersize their systems in order to beat the lowest price in any bidding competition. But then later on, once installed, they don’t perform adequately.

Our guide’s going to help you to calculate the approximate size and determine an adequate system configuration that will meet your application and process needs, which you can then use when comparing quotes from various manufacturers. Our guide’s also going to provide information that will be helpful for general baghouse maintenance, operation, as well as safety procedures.

If you have any questions, please, feel free to contact us for more information.

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Top 4 Reasons Why Baghouse Filters Fail

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An image of a baghouse filter that's been damaged by fire.
An image of the worn-out cuff of a baghouse filter

The regular operational life of a baghouse filter can be shortened by a number of factors. In this article we will discuss the top 4 reasons:

  1. Abrasion
  2. Exceeding Maximum Operating Temperature
  3. Chemical Attack
  4. Fire

1. Abrasion

The deterioration of filter bags through abrasion can be a result of a number of causes.  It can be caused by bags physically rubbing against each other, from the type of cleaning mechanism used or from where the dust enters the bag and impacts the fabric. The most common is caused by excessive particulate loads in the gas stream. Poor inlet design may lead to particulate laden air striking the filters in certain spots more than others such as near the bottom cuff, or strike the filters closest to the dirty-air inlet. In shaker baghouses, bags can deteriorate prematurely due to vigorous shaking particularly at points where the bags are attached. In pulse jet baghouses  the repeated rubbing of the bags against the support cages (especially if the cages are bent or rusty) can considerably shorten the working life of the baghouse filter. This is usually the case when the filters are not sized properly to the cage (otherwise known as the correct amount of “pinch”). 

“A properly designed, installed and maintained system can go a long way in preventing premature baghouse filter failure…”

2. Exceeding Maximum Operating Temperature

An image of dust that's collecting inside of a baghouse
Is your baghouse building up dust?

Baghouse filters are manufactured using various materials depending on the application they are being used for. These materials have different thermal durability, that is the upper temperature limit of the fabric. Thermal durability may also be a potential cause of early failure. When operating temperatures rise above the designed limits of the fabric, whether for short spikes or longer overages, filters will begin to degrade and eventually fail. This may be a sudden failure such as the filters melting or catching fire or it could result in less obvious damage that causes the bags to become brittle. Changes in the plant process, fuel source, maintenance shutdowns of other systems, etc., may result in temperature spikes that will irreparably damage the filters. 

3. Chemical Attack

Baghouse filter failure can also occur from a chemical attack. In its simplest form, this can be caused by using the wrong fabric for the chemical makeup of the gas stream. If gas stream characteristics are not taken into consideration when selecting the filter fabric and/or treatments/finishes, chemical attack can cause considerable damage to the baghouse filter.  Other times unexpected changes occur in the gas stream that can cause changes in the composition of the gas. For example, operating temperatures may drop below the dew point allowing chemicals in the gas stream to condense on the filters. This can have a dramatic effect on the life span of a baghouse filter, therefore proper fabric selection and maintain tight control over the process operating conditions and procedures can help eliminate bag deterioration caused by chemical attack.

4. Fire

An image of a baghouse filter that's been damaged by fire.
A dust collection filter damaged from fire.

Premature baghouse filter failure can also be caused by fire. This could range from a relatively mild occurrence to a far more serious event. A minor event could be caused by an ember or a spark entering the baghouse system. The ignition source can then be drawn through baghouse system and make make its way to the surface of the filter causing a hole to be burnt in the bag or for it to catch fire.

Additionally, if the dust collection system is not working properly dust accumulations may form that can then provide fuel for a potential fire or explosion. If then a spark or ember enters the system this built up dust can ignite causing a fire, which can then be dragged through the entire system causing a serious or even catastrophic conflagration. This often happens when a system is choked off with high pressure drop (differential pressure) across the filters or when the dust discharge system (baghouse airlock and any connected screw/pneumatic conveyors downstream) do not remove the dust from the baghouse quickly enough.

Prevention

A properly designed, installed and maintained system can go a long way in preventing premature baghouse filter failure. Following a regular preventative maintenance provided by a reputable dust collector OEM like Baghouse.com can keep your system in good working order. At times a dye leak test among other things can help technicians identify the exact cause of early filter failure.

Further Information 

For further information on baghouse filter failures, please see additional article on lesser known reasons of baghouse filter failures.

Need Help Ordering Baghouse Filters?

Whether you know exactly what you want or could use some help getting the right dust collection filter, we’ll put together a free quote with the perfect filter for you.

Contact Us Today!
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Find Leaking Baghouse Filters Faster with a Triboelectric Broken Bag Detector

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A entry level triboelectric broken bag detection system - Courtesy of http://auburnsys.com/

By Dominick DalSanto
Baghouse.com

Quickly finding and replacing leaking filters is crucial for keeping a baghouse operating at peak efficiency. The longer you take to replace the leaking filter the more likely you will have to report the event to your air quality control regulatory agency (reportable event) and the more abatement costs you will incur.

How Broken Bag Detectors Work

How Triboelectric Dust Detection Systems Work

How triboelectric bag leak detection systems work – Courtesy of http://auburnsys.com/

Triboelectric broken bag detectors measure the amount of static electricity generated by dust particles in an airstream. Dust particles generate an electrical current when they encounter the insulated metal probe in the ductwork. A dust particle directly impacting the probe creates a DC signal while a particle passing near to the probe generates an AC signal. The latest generation of triboelectric detectors (such as the Auburn Systems’ TRIBO series) unify both signals and then output a measurement of particle concentration to a nearby control panel or transmit it to a PLC.

Using a Triboelectric Broken Bag Detector as Early Warning

Most leaking baghouse filters begin as small holes or rips that overtime become worse and worse. Catching a leak quickly is crucial. The longer a leak persists the worse it becomes, often quickly causing a plant to exceed its maximum PM 2.5 emissions limits set out in its air permit. Additionally, abatement requirements quickly increase as a leak continues over time.

Older optical emissions monitors (i.e. opacity meters) and optical bag leak detectors can only detect a filter leaking so badly damaged that the increase in emissions exceeds 10% opacity (often greater than the maximum permissible levels for many air permits).

Triboelectric systems are sensitive enough to detect even the smallest of increases in dust emissions such as when a bag first begins leaking. Operators can then examine the realtime trending emissions data to see whether it was a sudden spike indicates a damaged bag (such as from quickly worn hole) or slow rise indicating wearing filters.

 

Using Broken Bag Detector to Pinpoint Which Filters Are Leaking

An added advantage of triboelectric bag leak detectors is they can enable operators and maintenance technicians to pinpoint exactly which bags are leaking and need to be replaced.

Personnel should carefully monitoring emissions while cleaning system runs. When emissions spike during one cleaning cycle it means that leaking filters are present. Using this method, maintenance personnel can trace the leaking filters down to a specific baghouse, compartment and even row (pulse jet only) of bags. This saves time and money over traditional dye leak testing.

However, on older units, or when first beginning to troubleshoot a unit dye leak testing should still form part of your maintenance schedule. Dye leak testing can pinpoint multiple leaks at once, and in structural components as well as filters.

By quickly pinpointing leaking filters maintenance staff also reduce the amount of abatement required after the leak is fixed.

Below is the sample data from a test conducted to determine the differences in performance between a triboelectric leak detection system and a typical optical system (opacity meter). Notice the huge difference in response time and abatement required.

Leak Test ResultsTriboelectric Bag Leak DetectorOptical System
Estimated Time to:
Detect LeakLess than 1 Hour2-3 days
Locate Leaking Filter(s)Less than 1 Minute2-3 Man Hours (dye leak test)
Clean Up LeakLess than 1 Man-Hour8-10 Man Hours
Estimated Size of:
Hole Detected1/4”8”
Dust Accumulation2.6 cubic feet60 cubic feet
Dust Clean Up ToolShopvacShovels

Source: https://cdn2.hubspot.net/hubfs/354686/BrandBuilder%20Solutions/Case%20Studies/Aluminum_Case_Study.pdf

Reduce Baghouse System Downtime

When a baghouse goes down it often brings much down with it, from specific equipment to entire production lines to even entire plants due to emissions or health and safety issues. Preventing unscheduled baghouse shutdowns directly impacts the bottom line. In some facilities, losses from just one down day can add up to tens of thousands of dollars in lost production, fines and other costs. Therefore, investing in the maintenance and upkeep of these baghouse systems is well worth the initial capital costs.

Triboelectric dust monitoring system often prove one of the most cost-effect ways to improve dust collector maintenance and operation. With the ability to monitor emissions in realtime and trends over time, operators can better assess the condition and operation of their baghouses than those who rely solely on differential pressure.

For example, by carefully analyzing the triboelectric data trends maintenance planners can accurately predict when filters will no longer achieve their require collection efficiency and need a changeout. Further, they can begin preparations for the changeout in advance, sourcing filters and cages, obtaining contract labor for the changeout and scheduling the changeout for the next most convenient time (e.g. yearly maintenance shutdown). Compare this with the added costs and stress involved when a changeout is done at the last minute!

Additionally, as mentioned above, triboelectric bag leak detectors also prevent downtime by quickly alerting plant personnel to any leaks as soon as they begin to form. By catching leaks before they become serious plants can avoid stoppages for abatement, repair and any possible fines or sanctions from air quality regulators.

Recap of the Key Points

  • Triboelectric bag leak detectors directly impact the bottom line of your baghouse by improving maintenance efficiency, reducing downtime
  • Increased detection range means finding leaks quicker, before they become reportable events
  • See when filters first begin to fail allows predictive maintenance planning to reduce inconvenient shutdowns
  • Find leaking filter bags quicker, pinpoint down to specific unit, compartment and row without a dye leak test
  • Comply with MACT standards that require triboelectric broken bag detectors over opacity meters

Interested in a Triboelectric Broken Bag Detection System?

If you would like to know more about our line of triboelectric broken bag detectors  and how they can benefit your facility contact us today for a free consultation and quote!

Contact Us Today!

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The 3 Most Overlooked Baghouse Preventative Maintenance Tasks

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Baghouse maintenance from Baghouse.com personnel
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PTFE Membrane Vs PTFE Finish – Is There a Difference?

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PTFE membrane on a baghouse filter under a microscope

Yes, there is a difference between the two. One is used to increase collection efficiency and one is used primarily for protecting the filter bags from chemical attack.

What Are PTFE Membrane Filter Bags?

PTFE membrane is semi-porous layer of PTFE bonded to the surface of a filter. This membrane acts at a permanent dustcake, capturing incoming dust particles (i.e. particulate matter or PM 2.5) on the surface of the filter (surface filtration) as opposed to normal filters that require a thick layer of dust buildup (dustcake) to actually reach peak efficiency. This means that PTFE membrane bags can operate at peak collection efficiency from the moment they are installed, and do not need to be precoated. Overtime, the membrane also works against the dust penetrating deep into the depth of the filter fabric, which is the cause of filter blinding. For this reason, PTFE membrane bags often last considerably longer than standard filter bags and have a more consistent differential pressure over time.

PTFE membrane on a baghouse filter under a microscope

PTFE membrane is a thin layer of PTFE laminated to the surface of a filter bag. It captures dust on the surface of the filter and easily releases the dust when pulsed.

PTFE Baghouse filters with PTFE membrane have the highest collection efficiency of all filters in production today. Bags using membrane technology can collect particulate matter down to 2.5 microns in size at over 99.99% efficiency. (In laboratory testing one OEM’s PTFE filters had 0.00% detectable emissions in the test rig). For this reason, in the applications with very tight emissions requirements, PTFE membrane filters are the standard.

Membrane bags are not recommended for a few limited applications, usually involving oils and hydrocarbons are these can close off the pores of the membrane and cause the filter to plug up.

What Are Filter Bags with PTFE Finish or Treatment?

In this use of PTFE, rather than creating a surface layer or membrane on top of the filter, the filter fabric is coated in a bath or spray of liquid polytetrafluoroethylene (PTFE) resin. This is done to protect the filter. The treatment improves the flex life, heat and chemical resistance and dust release from the fabric. This increases the service life and efficiency of the filters. PTFE finish is commonly used in applications with corrosive chemical compounds, sticky dusts, or high moisture contents.

Would you like to learn how PTFE membrane filter bags can improve your dust collector operation and save you money? Contact us today to find out more!

A Baghouse filter with PTFE (Teflon) Membrane

PTFE membrane or PTFE finish can be applied to a baghouse filter made from any fabric, such as fiberglass, polyester, or aramid (Nomex). It can even be used with pleated filters or cartridges.

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Can I Reuse My Baghouse Cages When I Change my Filters?

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Bent and rusted dust collector filter cages

The answer is that it depends…In many applications it is possible to reuse the cages once or possibly more. But in many other applications it may not be wise to reuse the cages.

Damaged Baghouse Cages From Corrosion and Mishandling

The main two types of cage damage we see are physical damage (bending, breaking, warping, etc.) and corrosion. Cages frequently get bent or broken by maintenance personnel over time by handling during changeouts and maintenance work. Other times, cages are damaged when stacked on top of each other for storage.  Additionally, fires or temperature excursions can warp cages.

Rip in a baghouse filter caused by a broken support cageCorrosion can occur from chemical attacks (e.g. acid flashes,) or upset conditions within the system. In some applications, high moisture levels can promote corrosion of the metal cages very quickly. And sometimes cages are stored outside uncovered  and left exposed to the elements.

Reusing Damaged Cages Will Cause Your Baghouse Filters To Fail Sooner!

There are three ways damaged or corroded cages cause filters to fail:

A bent baghouse cage has worn holes in the filter.

Bent or warped cages can eventually wear holes through your bags and cause massive leaks.Using damaged or corroded cages along with new baghouse filters will damage your filters and lead them to fail. This means you will experience leaks or even total filter failure much quicker than normal. Such failures can have high costs in terms of maintenance, possible system shutdowns, lost production as well as the costs of buying replacement filters sooner than normal.

  • When pulsed bent cages can cause the filters to rub against each other or against the sides of the collector causing the bags to tear open
  • Bent, twisted, or broken cages will have many sharp edges that can cut holes in the fabric very quickly when pulsed
  • Rusted or corroded cages will eat through the bag fabric and very quickly cause holes to appear.

In applications with very corrosive environment
(acid/alkali compounds, high humidity, condensation, etc.) such as foundries, dryers, chemical processing, etc., it is essential to avoid reusing cages that are damaged or corroded.

Even in applications with milder environments, the frequent handling of cages during repeated changeouts will eventually result in damage to the cages. Using cages in good condition extends filter life and improves efficiency by preventing:

  • Tearing or cutting filter on sharp edges
  • Damage from abrasion from other bags or unit
  • Corrosion eating through the fabric on the bags (Consider investing in galvanized, epoxy-coated or stainless steel cages to improve resistance to corrosion
  • Ineffective cleaning by ensuring the bags are properly fitted to the cages (Bags need to fit correctly
    across entire cage in order to get the required snap back when pulsed with air…not possible with bent cages

Reusing Damaged Cages Can Cost You Dearly

Bent and rusted dust collector filter cages

Corroded (rusted) cages will lead to early bag failure. Avoid reusing cages if they are damaged or corroded in any way.

Even minor rips, holes, and tears in the bags can lead to exceeding emissions limits. In many plants, such a problem will cause an emissions spike, becoming a “reportable event”, with possible fines and sanctions from regulators as a consequence. Additionally, any baghouse malfunction has the potential for causing plant-wide problems, that may lead to shutdowns, production losses and other costs far in excess of replacing the cages.
You can avoid all these problems and more by not using damaged or corroded cages in your baghouse. Additionally, if you keep spare cages on site at your facility make sure to store them where they are protected from corrosion and avoid stacking to many rows on top of another to prevent bending.

Baghouse Filter Cage Styles

Do you have corroded or bent cages in your baghouse? Let us give you a quote today for new cages along with your next set of replacement filters and receive a discount on both! Contact us now for a free quote.

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