Entries by dominickdalsanto

,

How to Maintain and Operate Your Dust Collector Using Differential Pressure

Powder & Bulk Solids Magazine Cover

Powder & Bulk Solids Magazine Cover

This article was published in the January 2025 Edition of the Magazine Powder Bulk & Solids. You can also read it in this link:

How to Maintain & Operate Dust Collectors Using Differential Pressure

Baghouse.com personnel monitoring the differential pressure in a cartridge collector

Regularly monitoring the differential pressure will give us insight on how our system is operating

Differential pressure is the key data metric used to determine how a dust collector is operating.  Monitoring this variable is like checking the blood pressure of a human body. Just as blood pressure indicates the health and efficiency of the circulatory system, differential pressure provides a vital measurement of how well the dust collector is functioning.

System operators and maintenance technicians must keep a close watch on the differential pressure at all times to ensure proper operation of the system. They must also monitor the differential pressure in order to plan maintenance as well as any modification to the system such as to increase capacity or improve efficiency.

What Differential Pressure Tells Us...

…About Your Dust Collector Filters

 

dust cake in a dust collector filter

Blinded filters with large temporary dust cake buildup will have higher leaking

● If The Differential Pressure Is High

  • ○ Consistently high DP is a sign that your filters are blinded (i.e. fabric fully saturated with dust particles). Once blinded, filters can no longer be cleaned and must be replaced.
  • ○ Blinded filters or even filters with large temporary dust cake buildup will have higher emissions (i.e. leaking). Check with opacity meters or broken bag detectors to verify emissions levels
  • ○ Insufficient air to cloth ratio for application will result in the bags being overloaded with dust and the cleaning system will be unable to effectively clean the bags.

● If The Differential Pressure Is Low

  • ○Abnormally low DP (below 3″) can be a sign of holes, tears or loose seams in the bags or that the filters are not installed properly (misaligned snap band on top load models, loose bag clamps on bottom load units).

 

…About Your Cleaning System

 

blinded pleated filters

Inadequate bag cleaning will result in higher DP since the dust cake will build up faster than it can be cleaned off

● If The Differential Pressure Is High

  • ○ Inadequate bag cleaning will result in higher DP since the dust cake will build up faster than it can be cleaned off
  • ○ In a pulse jet dust collector this could be caused by low compressed air pressure, contaminated air (dirt, water, or oil in air reservoir), misaligned installed blow pipes or misaligned/missing cage venturi.
  • ○ If the cleaning cycles (i.e. air pulses) are not set correctly the bags will not be cleaned properly. (“On Time” is how long the pulse valve is opened. If set too long the air burst will be too weak to clean the bag. If set too short it will not release enough air to clean the entire length of the bag.)
  • ○ The order the bags are cleaned (called “firing sequence”) should be staggered (1, 4, 2, 5, 3, 6) so that successive rows are not cleaned one after another (e.g. 1, 2, 3, 4, 5, 6,).

 

● If The Differential Pressure Is Low

  • Holes in a dust collector filter bag

    High compressed air will lead to early bag failure, often creating abrasion problems or even creating holes in the fabric

    ○ Over-cleaning of bags will place undue wear on the filters and lead to early failure.

  • ○ While if the compressed air pressure is too high it will clean the filters better, it also will lead to early bag failure, often creating abrasion problems or even creating holes in the fabric.
  • ○ Since emissions are at their highest when the filters are pulsed, over pulsing leads to increased emissions

 

…About Problems with Your Dust Collection System

● If The Differential Pressure Is High

  • ○ Sudden changes in DP can be caused by upset conditions or changes in the process the system is venting. Any problems in the dust collector could be sign that something potentially far more serious is taking place further upstream from the unit.
  • ○ Consistently high DP might be a sign that the system is undersized and not able to keep up with the load placed on it.
  • ○ Worn out baffle plates, dropout boxes, and poor airflow design lead to overloading of filters and high DP.
  • ○ Excessive dust build-up in the hopper can lead to dust reentrainment and overload the filters.
  • ○ Wet or sticky dust, which is difficult to clean, can be a sign of leaks near the hatches or cracks in the baghouse structure that allow moisture or cold air to enter causing condensation on the filters.

● If The Differential Pressure Is Low

  • ○ Cracks or holes in the structure, or the tube sheet of the dust collector can cause significant reductions in DP and lead to an enormous surge in emissions.

Beware of False Readings!

Magnehelic pressure gauge

If operators have incorrect readings it could result in damage to the system, increase emissions, or even fire and combustible dust hazards

As mentioned in previous articles, it is vital to make sure the differential pressure readings coming from the unit are accurate. To this end, it is best to make maintenance on the airlines, gauges, and controllers a regular part of the dust collector’s preventative maintenance program.

Conclusion

How many maintenance and operation decisions regarding your baghouse dust collector are impacted by differential pressure? 

All of them!

 

 

Do you have questions about differential pressure? Do you have some strange readings and are not sure what they mean? Please call us or email us at info@baghouse.com and let us see how we can help you!

, ,

4 More Ways To Avoid Undersizing a Dust Collection System

In addition to the points we mentioned in our article How to Avoid Undersizing a Baghouse Dust Collection System, here are a few additional methods to help ensure you get the right system for your operation:

Baghouse variables such as air-to-cloth ratio, power consumption, fan capacity, installation footprint, bag material, cleaning cycle type, required bag life, etc., need to be considered when designing the system.

Baghouse variables such as air-to-cloth ratio, power consumption, fan capacity, installation footprint, bag material, cleaning cycle type, required bag life, etc., need to be considered when designing the system

1. Set Technical Standards

On medium to large jobs (say $1 million+), pay an A/E, or a trusted baghouse consultant, to write a spec setting minimum technical standards for air-to-cloth ratio, power consumption, fan capacity, installation footprint, bag material, cleaning cycle type, required bag life, etc., and spelling out exactly what NFPA/OSHA performance standards will have to be met. The installed equipment will actually have to pass a field test before the vendor gets the last 10% of his fee, or a performance bond will have to be posted by the vendor. This type of detailed spec will scare off 90% of the “corner cutters.” Then, pay a testing company to actually do the test.

 

 

2.  Verify Vendor Experience

Customer References List 2024 for Baghouse.com

For smaller, low-cost projects, you can still ask each vendor for a contact list of their past customers who have installed their equipment for applications similar to yours in the last 3 to 5 years. 

Again, this will eliminate any vendors who lack experience with your type of problem or who enjoy shafting their customers. Then, actually make the phone calls and talk to the plant engineer responsible for keeping the unit operating. You will be amazed at how much information you can get for free from both happy and unhappy past customers.

"The vendor assured us that the system would handle our needs, but it was undersized from the beggining. We’re constantly replacing filters and dealing with high-pressure drops. In hindsight, I realize we should have consulted a dust collection expert before making the purchase."

3. Compare Multiple Vendors

Maintenance Manager contacting different vendors asking for ballpark quotes for their dust collection system

Instead of just contacting two or three vendors with your in-house preliminary spec, contact five or six, and ask for quick, ballpark, budgetary quotes. Within a few weeks, you will know which vendors are unrealistically below (or too high above) the “pack” to further bother with. Do this for 2 or 3 projects and you should get an excellent idea of which one or two vendors in your area are a trustworthy, economical fit for your operation, and you can just use them in the future.

 

3D design of a dust collector and the ductwork

4. Plan for Future Growth

When specifying your dust collection system, always consider your plant’s potential for future expansion. Systems that are undersized today will be even more problematic if your operations scale up. It’s a good idea to leave some room for increased airflow or additional filter capacity if your facility is expected to grow in the coming years.

By following these steps, you can significantly reduce the risk of ending up with an undersized dust collection system that costs you more in the long run due to operational inefficiencies, fines from non-compliance, and higher maintenance costs. 

, ,

Should I Change My Filters on a Schedule?

All Industrial Baghouse filters require periodic changing to new filters. But the question is, when?

Quite often a decision to replace the filters occurs after some kind of safety hazard becomes evident (e.g. elevated ambient dust levels or combustible dust hazards, etc.) or when the filters have literally fallen apart and they can no longer function without replacing them.

The time to change filters on an industrial dust collector is not by any means uniform across all industries. Many times it’s not even entirely clear who has the responsibility to make the necessary changes, maintenance planners, operators, plant management, production staff, compliance engineers, etc. 

How Most Plants Decide When to Change Filters

Pleated filters blinded by a dust cake

Ignoring the signs of blinded filters can lead to costly fines

Regrettably, most plants conduct filter changeouts quite haphazardly and randomly, having have no plan whatsoever. Some just pick a moment and decide to replace them without any particular reason other than a “feeling” that they are old. Others ignore all signs of degrading capacity and efficiency until they receive notice after an inspection finding them well in violation of emissions limits. Quite often a decision to replace the filters occurs after some kind of safety hazard becomes evident (e.g. elevated ambient dust levels or combustible dust hazards, etc.) or when the filters have literally fallen apart and they can no longer function without replacing them. On other occasions it only comes to the attention of the decision makers when the boss finds her car covered in dust in the parking lot. 

Obviously, such an approach has serious drawbacks. These include the potential for fines and sanctions for elevated emissions. Besides the obvious effects on production performance, worn out filters can also directly contribute to safety hazards from combustible dust and excessive ambient dust levels.  Additionally, this kind of approach makes it impossible to plan and budget for filter replacement, meaning a large capital expenditure occurs without warning. This can lead to an unexpected shutdown that could involve significant downtime. 

The Fixed Scheduled Method 

It does not take a business genius to realize that the approach outlined above is not feasible and far more costly in the long run than being proactive about filter replacement. For this reason, a good number of plants instead decide to go a different route and in their minds “play it safe” by scheduling their filter change outs at fixed intervals. Usually they will get an opinion regarding the “recommended service life” of their particular filter from the bag supplier or an outside air pollution control consultant. These so-called “experts” may recommend a replacement schedule of anywhere from 1 to even 6+ years. 

By scheduling the changeout in advance these facilities think they are avoiding the mistakes of the others, namely the unexpected shutdowns, the possibility of exceeding emissions limits, controlling dust hazards, etc. While this is true to an extent, it makes no allowance for the fact that filter failure does not occur in exactly the same way in every application. The causes of filter failure are complex and involve more than just time under use. Process conditions, upset events, weather, maintenance, capacity, manufacturing, cleaning settings, operation parameters and other factors all affect how long a set of filters will last. By arbitrarily setting a date for changeouts and not basing it on actual bag performance they will replace the filters sooner than needed or risk running the filters too long.

The Better Way - Replace Only When Needed Using Triboelectric Monitoring

Our stack emission monitoring devices are tailored to integrate into your specific application, regardless of your industry or application

Our stack emission monitoring devices are tailored to integrate into your specific application, regardless of your industry or application

In contrast to the above methods, many facilities have realized the benefit of basing this decision on actual performance data from their baghouses. In this regard, no other monitoring device comes close to the capabilities of a triboelectric dust monitoring system such as the Auburn TRIBO series. Armed with trending emissions data gathered in real time, maintenance planners can accurately predict when filters will begin to fail (i.e. no longer capable of meeting emissions limits), thus allowing them to plan ahead for filter replacement and avoid unexpected shutdowns. 

"Before we started using a triboelectric monitoring system, filter changes were a guessing game. Now, we can precisely plan replacements based on actual collected data, and it's saved us both maintenance man hours and money."

This predictive maintenance approach saves money on filter change outs by allowing planners to beginning sourcing quotes for filters in advance and lining up labor for change out thus avoiding additional charges for expedited delivery and rush mobilization. It also allows for the shutdown to be scheduled at the most opportune time, such as during a quarterly maintenance outage. 

In addition, continuous monitoring with triboelectric systems means that if any unexpected problems do occur before the change out, such a leaking filter, or damage from upset conditions in the process, compliance engineers can immediately detect a problem quickly and arrange for repairs before it escalates. 

"Honestly, relying on 'gut feelings' to replace filters led us to costly mistakes in the past. With predictive data from our triboelectric system, we plan filter changes during regular maintenance, avoiding disruptions and unnecessary expenses."

Conclusion

Despite the wishes of many plant managers, filter changeouts do not go away if ignored. Neglecting to address the issue with a concrete strategy only causes more problems, some with the potential to force shutdowns or cause catastrophic damage. On the other hand, preemptively changing filters based solely on a rigid timetable, regardless of performance and actual operating conditions “leaves money on the table”, with the plant forced to purchase more filters and shutdown for changeouts more often than necessary. 

In contrast to these two extremes, with the help of triboelectric dust collector monitoring systems operators and maintenance planners can see exactly when the filters will need to be replaced and can plan accordingly. This will lead not only to direct savings on filters and changeout labor, but also better operation and more stable performance. 

Would you like to see how a triboelectric monitoring system could help you extend the life of your filters? Contact us today! 

, ,

The Importance of Correct Compressed Air Pressure in a Pulse Jet Dust Collector

Air Compressor Gauge in a Pulse Jet Dust Collector

The pressure supplied by the compressed-air system must be high enough to clean the entire length of the bag during the pulse.

In our previous article The Importance of Dry and Clean Compressed Air in a Pulse Jet Industrial Dust Collector, we discussed the importance of using dry and clean compressed air. Along with this requirement, it is also very important that the compressed air is set at the correct pressure.  

Optimize Dust Collector Compressed Air Pressure to Balance Filter Life, Efficiency and Airflow 

The pressure supplied by the compressed-air system must be high enough to clean the entire length of the bag during the pulse, but not so high that it damages the upper portion of the bag. Insufficient cleaning of the bag may gradually increase pressure drop and reduce the useful bag life. 

If the compressed-air pressure is too low, which is usually more common than excessive pressure, it may be caused by wear of the compressor rings, leakage in connections, or excessive draining of the reserve of the compressors by other equipment tied to a common supply line. Additionally, if the pulse valves, air header tanks or connecting pipes on the unit itself have leaks, then the absolute pressure or the effective pressure at the blowpipe will be lower. 

Air Compressor

If the compressed-air pressure is too low, it may cause excesive wear of the compressor components

For most applications using felted filter media, compressed air at roughly 70 PSI (Per Square Inch) is adequate for proper cleaning of the filter elements. Pressures between 100 and 120 PSI may be recommended for some difficult  applications where other options to improve cleaning efficiency are not viable. Operators running their systems at pressures above 100 PSI should first consult a dust collection expert at Baghouse.com for advice and recommendations on how to improve performance.

Compressed air pressures below 70 PSI may be required under special circumstances such as when using cartridges, pleated filter elements or with certain filter medias such as fiberglass. These situations often call for special design and sizing of the dust collector in order to function correctly.

Guidelines for Setting Compressed Air Pressure on a Pulse Jet Baghouse

Pulse Jet Air Compressor Gauge

If filters are not cleaning sufficiently, raising the air pressure may be one of several things to try to improve operation.

The following general guidelines can help you to set the the correct pressure of compressed air for your baghouse: 

  • — Start at 60 PSI and go up as needed by the application. At no point should it go above 100 PSI unless advised to do so by a reputable dust collection systems engineer.
  • — Pleated filter systems and cartridge systems may use much lower PSI for cleaning depending on the design of the unit and the application (airflow, dust load on filters, how hard the dust is to pulse off, moisture problems, etc.)
  • — If filters are not cleaning sufficiently, raising the air pressure may be one of several things to try to improve operation. However, it alone will not solve the problem in most cases. Often, fixing other problems such as high can/interstitial velocity, will improve things so that you can actually lower the PSI and have better cleaning. 

For help optimizing your dust collection system please contact Baghouse.com for more information or to arrange a site visit and/or training course.

, ,

Why Use Experienced Baghouse Technicians for Your Next Filter Replacement

While many facilities often choose to install replacement filters using in-house labor, usually to keep costs down, it is not always the best idea to simply assume that using in-house labor is the best option. Here’s why relying solely on your maintenance staff for baghouse filter installation may not be the best option.

The Risks of Using In-House Labor

Dust leaking due to incorrect installation of filters

Improperly installing the bags (not sealing them correctly, improper tension, etc.) can lead to leaks and early failure of the bags

When workers without specialized training attempt to service a baghouse, several issues can arise. For example, filter bags, particularly those with PTFE membranes, are fragile and require careful handling. Untrained personnel can easily damage the bags during installation, leading to early failure or leaks. Furthermore, incorrect installation techniques, such as failing to properly seal the bags or applying incorrect tension, can result in compromised system performance and costly downtime.

In addition to potential damage, in-house workers might not be familiar with the unique safety hazards associated with baghouses. This can lead to injuries, further increasing costs for the facility.

Efficiency Concerns

Even if the installation is completed without incident, it usually takes much longer for in-house labor to replace filters compared to a trained baghouse service team. Experienced technicians understand the design and operation of various baghouse types and can perform replacements safely and efficiently. When in-house teams handle filter changeouts, it often leads to delays, increased labor costs, and extended facility downtime. These delays are especially costly when mistakes are made during installation, requiring additional resources later to fix the problems.

For instance, one facility chose to have its regular maintenance workers replace filters in 18 compartments, each containing 200 reverse-air filters with springs and chains. The in-house team took an average of three days to replace the filters in one compartment, often making mistakes like improperly sealed bags or incorrect tension. In contrast, a professional crew completed the same work in just four compartments per day while also addressing additional maintenance tasks such as scraping rust scale from walls and performing leak tests.

Benefits of Hiring Professional Baghouse Technicians

Blowpipe support rusted and broken

Professional crews are trained to recognize underlying problems that may go unnoticed by in-house teams, such as broken supports of blowpipes, as seen here

Hiring expert Baghouse.com technicians can save facilities time, money, and resources. Professional crews are trained to recognize underlying problems that may go unnoticed by in-house teams, such as warped metal, failing welds, moisture issues, and abrasion damage. These early detections can prevent more serious issues down the line.

Conclusion

While using in-house labor to install baghouse filters may appear to be a cost-effective solution, the risks of improper installation, safety hazards, and inefficiencies can quickly outweigh any potential savings. In many cases, outsourcing this task to professionals pays for itself through increased efficiency and reduced risk.

Ready for your next filter changeout?

Would you like a quote on filters and cages, along with the changeout service?

 

, , ,

The Importance of Dry and Clean Compressed Air in a Pulse Jet Dust Collector

All industrial baghouse systems are designed with various cleaning methods in order to ensure correct operation and longevity of the baghouse filter. 

Dust collector filter diagram with air stream breaking the dust cake

As the bag flexes, the dust cake (built up dust on surface) fractures falls into the hopper below.

Today, the most common cleaning method used in industrial dust collectors is pulse jet or reverse jet cleaning. These methods involve removing the dust from the bag filters using a blast of compressed air. The air blast creates a shock wave that causes the bag to flex or expand as the shock wave travels down the bag. 

However for trouble and maintenance free operation, it is extremely important that the compressed air used in the system is clean, dry and at the correct pressure. In this article we will concentrate on the importance of dry and clean compressed air. A discussion on the importance of proper air pressure will be covered in a another article. 

Clean, Dry and Oil Free Compressed Air

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

Dust collection filters completely covered in build-up from moisture

Dirt, rust, and scale can prevent diaphragm valves from operating properly. Moisture can cause valves to freeze in cold weather.

Moisture and oil can also cause deterioration of the valve diaphragms, and if the interior of the filter bags become coated with moisture and/or oil, eventual blinding of the filter media will occur. Blinding of the filter material occurs when the filters become so impregnated with dust in the depths of the fabric that you cannot clean them 100% anymore and the airflow through them will never go back down, resulting in premature failure of the baghouse filters. 

How to ensure the Compressed Air is:

Clean

In order to trap small amounts of dirt, rust and scale, a small dirt leg is installed at the point where the air line connects to the compressed air header. In situations where large amounts of dirty rust and scale are present, and inline filter or a centrifugal separator is required. 

Dry

A Liquid Moisture Trap (automatic moisture drain) must be installed on the compressed air receiver.

A Liquid Moisture Trap (automatic moisture drain) must be installed on the compressed air receiver.

There are a number of solutions to ensure that the Compressed air remains dry. For example a Liquid Moisture Trap (automatic moisture drain) must be installed on the compressed air receiver. These automatic drains come in a variety of float, piston, and pilot operated types. When small amounts of moisture are present it can be handled by inline air filters with automatic drains. For large amounts of moisture, a centrifugal separator and chemical dryer may be required. For more specific situations, for example climate and indoor temperatures, other methods are used to ensure the compressed air remains dry.

Much of the above mentioned equipment used to remove moisture can also be used to remove oil and oil mist. For installations where oil and oil mist are the major problem, inline filters are available that use desiccant adsorptive elements or packed beds of an oil absorbing granular organic polymer.

Conclusion

Diagram of a pulse jet system

During regular operation, Pulse Jet Industrial filtering systems do not stop the flow of dirty air into the baghouse and it is the only true “online cleaning” method.

Bag cleaning cycles are initiated to keep the overall pressure drop across the baghouse within the designed range. Therefore the importance of clean, dry, oil free compressed air cannot be over emphasized. However another important factor to take into consideration is the pressure of the compressed air. This will be discussed in an upcoming article.

For further information or to arrange a site visit, please contact us at Baghouse.com.

What is a HEPA After-Filter and When Do I Need One?

In the search for cleaner indoor air, many industries face the challenge of maintaining optimal air quality within their facilities. One effective solution is incorporating a dust collection system equipped with a High Efficiency Particulate Air (HEPA) after-filter. Let’s review some of the most frequent questions regarding this type of filter.

HEPA filter at industrial facilities
Positioned on the clean air side of the unit, the HEPA after-filter acts as a secondary filtration stage, capturing even the tiniest microscopic particles before the air is returned to the facility.

 

Question: How Is a HEPA filter made?

Answer: HEPA filters are made from polyester, polypropylene, or fiberglass fibers that are tightly interlaced with diameters of less than one micron. The fibers are twisted, turned, scattered, and randomly placed in different directions to create a mesh maze without a straight through path. The openings between the fibers are smaller than a half micron, which is why HEPA filters can catch particles smaller than 0.3 microns.

Question: How Does a HEPA After-Filter Work?

Answer: When a dust collector draws in dirty air and dust particles, the primary filters capture larger particles while allowing cleaner air to pass through. However, ultrafine particulates may still escape through the primary filters. Here’s where the HEPA after-filter comes into play. Positioned on the clean air side of the unit, the HEPA after-filter acts as a secondary filtration stage, capturing even the tiniest microscopic particles before the air is returned to the facility.

Inside a HEPA filter
HEPA filters are made from polyester, polypropylene, or fiberglass fibers that are tightly interlaced with diameters of less than one micron

Question: How is a HEPA filter different from regular filters?

Answer: The main difference between a HEPA filter is that it is made of thin fibers of glass and activated carbon-based materials. Regular filters are made of porous materials like cotton, paper sheets or polyester. Most importantly, HEPA filters offer much higher filtration efficiency (MERV 16 or higher) compared to a standard fabric filter.

Question: When Do I Need a HEPA After-Filter?

Answer: Consider incorporating a HEPA after-filter in the following scenarios:

  • — If your process generates fine particles that pose health risks or can contaminate products.
  • — When regulatory or industry standards demand exceptionally high air quality.
  • — If the collected dust contains hazardous materials, allergens, or carcinogens.
  • — When you aim to recirculate filtered air back into the facility, necessitating cleaner air to improve indoor air quality.

Question: Does a HEPA After-Filter Help Against COVID-19?

Answer: Yes. By incorporating a HEPA after-filter into your dust collection system, you can significantly reduce the risk of airborne transmission of the virus within your facility. While other safety measures like social distancing and mask-wearing are essential, purifying the air with a HEPA filter adds an extra layer of protection.

Different stages of a HEPA after filter
HEPA after-filter serves as a powerful ally when searching for cleaner indoor air quality, particularly in industrial settings

 

Question: What Does it Cost to Add a HEPA After-Filter?

Answer: First, the size and quantity of HEPA filters for your system will depend on the airflow of your system. Each HEPA filter is sized for a specific airflow, and multiple filters may be required to meet the required airflow and static pressure requirements of your system. Once the quantity, size, and type of HEPA filter is determined, a HEPA filter housing is needed to house the filters, along with ductwork to connect your HEPA filters to your existing dust collection system, and route clean air to the desired location. A Baghouse.com dust collection specialist can help you size and spec out a HEPA after-filter and provide a quote for your project.

 

In conclusion, a HEPA after-filter serves as a powerful ally in the ongoing battle for cleaner indoor air quality, particularly in industrial settings. Baghouse.com can provide expert guidance in selecting the right HEPA filter and offer comprehensive support from installation to maintenance. 

 

Do you have any additional questions regarding the HEPA filters? Contact us today to discover how we can enhance your dust collection system with HEPA filtration.

 

Contact Us to Speak to One of Our Baghouse Experts


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

, ,

Why Are Some Baghouse Filters More Expensive Than Others?

Why Are Some Baghouse Filters More Expensive Than Others?

Baghouse.com sells a lot of filters each year, including thousands of bag filters and cartridge filters in the most common configurations as well as just about every type of unusual or obsolete filters that are still found in baghouses around the country.

While we are one of the most experienced companies in the industry, with a huge network of filter fabrication shops and the economies of scale that come with large volume manufacturing, our filter prices are not always the cheapest – why not?

The answer comes down to two factors: filter design and filter quality.

Filter Design: The Right Filter for the Application

Filter and cages

Baghouse filters are used in a vast range of industries and applications

Baghouse filters are used in a dizzying range of industries and applications, from nut processing to aerospace manufacturing to battery recycling to silica mining. Every application has a specific dust type, air temperature, air flow and velocity, dust content, and chemical profile that must be understood to properly identify the correct filter media for the application. To further complicate matters, just about every dust collector manufacturer designs their equipment to use a very specific filter size and configuration – from shaker filters with hangers, to top-load baghouses with snap-bands and cages, to bottom-load baghouses with thimbles and band clamps. The variables are virtually endless.

The cost of your filters of the lifetime of a dust collector depends on having the correct filters installed. Use the wrong filter media and the filters will be damaged quicker – the wrong configuration or size and they will leak, requiring replacement sooner.

Some filter designs are less expensive than others – a standard top-load bag filter made from 16-ounce polyester fabric is produced in large volumes and is thus less costly than a specialty fabric (Aramid, for example). However, if your gas temperature spikes higher than 275 degrees F. Using the wrong filter will result in an early failure and the cost of a new set of bags.

 

Summary: Selecting the correct filter design will result in the lowest total cost of filters in the long run.

Filter Quality: Risks of Selecting the Lowest Bidder

Assuming you have selected the correct filter media, filter configuration, and size, your purchasing decision should just be to select the lowest price offer right? Not so fast – just like some car manufacturers offer better quality than others, not all filter makers are equal. The biggest differentiator is quality.

Baghouse.com personnel recently evaluated a dust collection system at a new customer. The customer wanted to know why their filters had failed prematurely. The baghouse was processing gypsum dust with a very fine particle size requiring a PTFE membrane, used for high-efficiency filtration of fine dust. However, shortly after installing the filters, the customer noticed that their emission limits were well over their permitted limit.

Microscope image of bag filter

Microscope view of this filter shows PTFE (white) was sprayed on, not applied via a membrane.

 

Baghouse.com sent a filter sample to the lab and discovered that, instead of a PTFE filter membrane, the filter manufacturer had sprayed on a PTFE layer which left large gaps in the PTFE coverage of the filters, allowing dust to pass through and into the atmosphere. The purchasing specialist at this customer had chosen these filters due to the lowest quoted price, but the result was the purchase of a new set of higher-quality filters, much sooner than anticipated.

Summary: Focus on long-term cost, not just the lowest price tag.

Expertise & Quality

At Baghouse.com, our mission is to be the most trusted name in dust collection. That means that we never offer a sub-par product, either an improperly designed filter or a low-quality filter, to win business from our competitors.

With our 40 years in the industry, our team of experts will ensure that any filter we sell is the correct design for your application. Additionally, the filters we sell are the highest quality and made in the USA. We expect our customer relationships to last a lifetime, not just until we get a PO in hand. We may not always be the lowest bidder, but we strive to offer the most long-term value for our customers.

Other Causes of Baghouse Filter Failure

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.

 

Video: Intro Guide to Sizing and Designing Your Baghouse

 
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.