Purchasing a Dust Collector: 6 Factors to Keep in Mind

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Baghouse systems

If you’re in the market for a dust collector, whether it’s a new purchase or an upgrade for your facility, it’s essential to make an informed decision. A dust collector is a crucial component for maintaining air quality and safety compliance in various industries.

To ensure you get the right dust collector for your specific needs, consider these six key factors:

1. Dust Control Requirements

Different processes generate various types of dust, from wood chips to welding fumes or grain dust. It’s vital to not only recognize the type of dust you generate but also how your processes create it. How much dust is generated by the process? Is this dust hazardous or does it require special handling? Are there regulatory standards for air quality that you need to meet?

In response to these challenges, two primary dust collection systems have proven effective: baghouse-style dust collectors and bin vents. These systems offer reliable solutions for grain dust control, each with its unique advantages.

2. Customization Options

Dust collectors are not one-size-fits-all solutions. The space constraints of your facility may require customizations in terms of height, footprint, or additional features like discharge devices, monitoring equipment, or fire and explosion mitigation tools.

Other common custom features include:

  • Rotary airlocks, screw conveyers, or other special dust discharge equipment
  • Special construction materials like stainless steel for food applications
  • Customer controls including integrated motor starters, timer boards, differential pressure gauges, or outputs to connect to control systems
  • Special sizing for very light dusts or restricted spaces

3. Complete System Design

Baghouse system

The type of dust and your operational needs will determine the most suitable dust collector. In the cases where dust is hard to collect due to being too fine or sticky, you should obtain a dust collector that is equipped to capture it effectively. Another instance could be if your industry demands complying to food-grade standards.

Additionally, different dust collector styles are more suited than others for certain applications. Generally, cartridge collectors work best for light dust loads and fine dusts at lower temps, but perform poorly with heavy dust loading, irregularly-shaped dusts, or sticky dusts. Baghouses on the other hand, are able to work in a wide range of applications. Many companies will only offer you a single style and try to convince you it can do more with less so it appears to be the cheapest bid, regardless of how well it will perform later.

Finally, if your dust is hazardous or explosive, it’s crucial to obtain a specialized system (collector, ductwork and safety devices) designed to comply with NFPA regulations.

4. Installation Simplification

Baghouse installation

The ease of installation depends on the size of the dust collector and its location. Smaller collectors located close to the dust source may eliminate the need for extensive ductwork, simplifying installation. Understanding your processes, localizing dust collection, and minimizing collector size can streamline installation. It is critical to work with an expert in dust collection systems who can foresee potential installation issues and address them early on to ensure a smooth install.

5. Long-Term Value for Your Investment

Your investment in a dust collector goes beyond the initial purchase. Think about the operational costs for the entire lifecycle of the system. Factors like replacement filters, downtime due to maintenance, and energy consumption need to be analyzed closely. Evaluating collector style, location, and design can help you make a cost-effective choice. Watch video: Intro Guide to Sizing and Designing Your Baghouse

6. Post-Purchase Support

Baghouse.com is an original equipment manufacturer with extensive experience in design, installation, and parts supply. This makes us stand apart from others in the industry who simply resell catalog components. Our extensive experience enables us to provide tailored solutions, designed to meet every industry need. From design to installation and ongoing support, choosing us means opting for a partner invested in the success and longevity of your dust collection system.

In conclusion, investing in the right dust collector will significantly contribute to a safer and more efficient workplace. Making a well-informed decision ensures that your dust collector not only meets your current needs but also serves you for years to come. It’s an investment in both your facility’s air quality and the longevity of your operations.

Frequently Asked Questions

How do I know if this dust collector will work for my application?

When talking about dust collection, it’s rarely a “it works or it doesn’t” scenario; rather, it spans a spectrum from highly effective to very poor performance. While some smaller/cheaper systems may “work” for an application, that’s not the whole story.

A well-designed system, with the right collector size and style, operates efficiently, maintains low operating costs, and captures all target dust without compromising safety or emitting pollutants. However, poorly functioning systems may fail to capture all dust generated by a process, leading to compromised product quality, frequent filter blinding, high maintenance costs, safety hazards, and/or emissions that risk exceeding air permit limits.  At Baghouse.com, we help you choose the right system, ensuring not just functionality, but the best performance.

Different companies recommended different kinds of dust collectors, with an ample range of prices. What should I consider when choosing my supplier?

It’s not uncommon for companies to try to convince their clients that a one-size-fits-all approach is best when it comes to dust collectors, either because it’s the only style they manufacture or because they aim to provide the lowest bid. However, at Baghouse.com we offer multiple kinds of dust collectors and we prioritize recommending what works best for your application rather than trying to be the lowest bid without regard for how it works. We ensure that you not only get a dust collector but the right one that aligns perfectly with your operations.

Who can I contact if I have technical issues with my dust collector?

Whether you need parts, filters or a system inspection to improve the efficiency of your dust collectors, the experts at Baghouse.com can simplify the maintenance process by providing you with the knowledge and supplies needed that will save you lots of downtime, money, as well as headaches!

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 to Select the Right Dust Collector Rotary Valve

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Explosion rated rotary valve

Dust collector rotary valves, also known as rotary airlocks or rotary feeders, are essential components in many industrial processes that involve the handling of bulk materials and are very commonly used in dust collection systems. These valves play a crucial role in controlling the flow of material, preventing air and pressure loss, and ensuring minimal product loss during processing. Selecting the right dust collector rotary valve is of utmost importance to maintain system efficiency, safety, and product integrity. In this article, we’ll delve into the different types of rotary valves and the key considerations for selecting the right one for your specific application.

Rotary Valve

Understanding Rotary Valves

Rotary valves are mechanical devices that facilitate the transition of materials from pressurized environments, such as dust collectors, to unpressurized points, like storage bins or drums. They come in various types, sizes, and materials to suit different industrial applications.

Types of Rotary Valves

  • Drop-Through Rotary Valve: In drop-through valves, product feeds into an inlet at the top, typically from a gravity-fed hopper, and exits through an outlet below. These valves are often used in applications where the primary function is to maintain air pressure differentials.
  • Convey Through (Blowing Seals) Rotary Valves: In convey-through valves, product enters the inlet and is directly fed into a pneumatic convey line connected to ports on the bottom sides of the housing end covers. These are more suitable for applications where height limitations exist, and the valve feeds a pneumatic conveyor directly.

Choosing the Right Rotary Valve

Selecting the right rotary valve depends on several critical factors:

1. Application Type:

  • Airlocks: Used in applications where maintaining pressure differentials is crucial. They allow material to flow between different pressure zones and are commonly found in cyclone and baghouse outlets.
  • Feeders: These valves control the rate at which material flows through the valve by metering the bulk powder material’s flow. They are suitable for low-pressure or gravity-fed applications, such as filling packaging machines.
  • Airlock Feeders: Combining the functions of airlocks and feeders, these valves are versatile and can be used for feeding pneumatic conveyors or moving products in and out of pressure and vacuum receivers.

2. Materials of Construction:

The choice of materials for the housing, rotor, drive, and accessories is crucial to match the requirements of your product and the operating environment. For example, some applications may require stainless steel for its resistance to chemicals, while others may need cast iron or chrome-plated cast iron for durability.

Adjustable rotors allow for tips to be adjusted to account for wear, and flex tip rotors are designed to maintain an airtight seal while preventing material jams. These are just a couple examples of the type of material and design options available.

Sanitary rotary airlock components

Sanitary rotary valve components

3. Ease of Cleaning:

For applications where frequent cleaning is necessary, choose a rotary valve designed for easy disassembly. Look for valves that facilitate access to product contact surfaces for cleaning. Hygienic applications should ensure the valve’s surface finish, seals, and construction meet regulatory standards.

Typically, open end rotors are easier to clean and maintain. These are often used with lighter or finer materials, to minimize the risk of material becoming trapped in the space between the endplates and rotor disc.

Rotary Airlock Removal

4. Explosion Protection:

In environments where explosion isolation is required, make sure the valve design complies with standards like NFPA to ensure safety in case of an explosion.

Explosion rated rotary valve

NFPA compliant rotary valve

5. Pressure:

The pressure of your conveying system is a key determinant of the required valve durability. Dilute phase pneumatic conveying systems typically operate between 4 and 8 PSI, while dense phase systems operate over 15 PSI. Valves for high-pressure or vacuum applications need to be designed to withstand the conditions, possibly requiring additional venting systems to prevent air leakage.

6. Temperature:

Consider the operating temperature, as extreme heat or cold can impact the choice of materials, rotor design, and airlock capabilities of the valve. Ensure the selected valve can withstand the temperature conditions of your application.

Selecting the right dust collector rotary valve is a critical decision for maintaining the efficiency and safety of your industrial processes.

By considering the type of valve, materials of construction, ease of cleaning, explosion protection, pressure, and temperature, you can make an informed choice that ensures optimal performance, minimal product loss, and a safe working environment. Collaborating with experts in this field such as Baghouse.com can be invaluable in making the right selection for your specific application.

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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Your Guide to the Dust Collection Maintenance Checklist

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Maintenance Checklist Main ImageBaghouse.com 2023

An essential first step in establishing an effective maintenance plan is the creation of a dust collector maintenance checklist. This checklist, tailored to your specific system, helps facility managers and maintenance staff perform periodic inspections as needed. In this article, we’ll explore the importance of a dust collector maintenance checklist, why you need one, and what to include in it.

Baghouse filter change

Routine maintenance is critical to ensure your dust collection system operates efficiently.

Why Do You Need a Dust Collector Maintenance Checklist?

Maintenance Checklist Image

Your maintenance checklist should cover the entire system.

Baghouse system designs such as shaker, reverse-air, plenum-pulse-jet, and pulse-jet each require a checklist specific to their design. Regular inspections should be scheduled at various intervals, including daily, weekly, monthly, quarterly, semi-annually, or annually. By adhering to this routine, your dust collection system will continue to operate efficiently for years.

Neglecting regular dust collector maintenance can result in sluggish system performance, leading to costly repairs for both the dust collector and equipment affected by dust buildup. Repairs cause system downtime and production loss. Furthermore, an improperly functioning system can pose health risks to everyone in the vicinity, including workers, managers, owners, and visitors.

Signs That Your Dust Collector Needs Maintenance

Dirty filter bag

Your DP gage can indicate when filters are blinded and require changing.

General indicators that a dust collector requires maintenance include:

All of these problems are easily preventable with regular maintenance.

What Your Checklist Should Include

Below is a list of dust collector maintenance items and when to check them, depending on the system’s design:

Daily Checklist

  • Check and record differential pressure
  • Monitor air flow and dust collection pick-up points
  • Check discharge system (airlock, rotary gate, hopper high limit switch)
  • Perform visual and audible inspection of the baghouse
  • Inspect exhaust stack outlet – check for visible emissions
  • Monitor control panel pilot lights or meters
  • Check pulse-jet baghouse compressed air functionality

 

Weekly Checklist

  • Inspect the discharge system moving parts
  • Ensure dampers are in operation
  • Confirm solenoids are operating
  • Check diaphragm valves (listen to firing of pulse valves)
  • Inspect compressed airlines, including filters (clean and moisture-free)
  • Ensure hopper discharge device is working
  • Examine visible stack emissions
  • Inspect fan drive components

 

Monthly Checklist

  • Spot check the condition of bag seating or cartridge filter seal
  • Inspect for bag leaks, fabric wear, or holes
  • For reverse-air and shaker bags, check tension
  • Examine shaker baghouse moving parts
  • Record compressed air pressure
  • Clean compressed air filter
  • Check for corrosion and blade wear on the fan
  • Ensure the hopper is empty
  • Inspect door seals for deterioration
  • Check access doors for leaks
  • Inspect hoses and clamps
  • Examine baghouse housing for corrosion
  • Check gas flow rate
  • Blow out differential pressure gauge lines

 

Quarterly Checklist

  • Thoroughly inspect bags for wear
  • Inspect ductwork for dust accumulation
  • Ensure damper valves are seating properly
  • Inspect gaskets on all doors
  • Calibrate opacity monitor

 

Annual Checklist

  • Record the pulse duration and pulse delay
  • Check for general wear and tear
  • Inspect bolts, welds, inlet baffle plate, and look for signs of corrosion or paint flaking on support steel
  • Examine ductwork for dust buildup
  • Check hopper for wear
  • Perform a dye test for leaks
  • Replace worn parts on the cleaning system
  • Replace diaphragm internal components

A well-structured plan that includes a dust collector maintenance checklist benefits operators significantly. It ensures that routine maintenance is systematically scheduled and performed, leading to efficient, long-lasting dust collection systems and lower cost of ownership overall. By following the checklist at specific intervals and marking off completed tasks, you can help preserve your dust collector’s efficiency and longevity and avoid major surprises.

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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Investing in Quality Filter Cages and Venturis for Long-Term Savings and Performance

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Cage and Venturi Main ImageBaghouse.com 2023

 

Filter bag cages and venturis might not always steal the spotlight, but they are the heroes behind efficient and reliable dust collection systems. Neglecting the importance of these components can lead to a cascade of operational and compliance issues in your facility. At Baghouse.com, we understand the critical role played by filter bags, cages, and venturis in maintaining a top-notch dust collection system working perfectly. Let’s delve into why investing in quality components like these is a smart decision for your industrial operations.

The Crucial Role of Filter Cages

Filter cages might seem like simple components, but they are essential for the proper functioning of your dust collection system. When filter bags don’t fit snugly onto the cages or when cages are not replaced when needed, it can compromise the entire system. Neglected filter bag cages are often the root cause of many operational problems in industrial settings.

Cage Types

The purpose of a baghouse cage is to provide support for filter bags to stay open during the dust collection cycle.

 

 

Common Cage Styles

Common baghouse cage styles include rolled top (top load baghouses) and split collar (bottom load baghouses). Options include galvanized steel, stainless steel, or epoxy coated. Cages can also have integral or drop-in venturi for improved bag cleaning.

One key feature is the precise fit between the filter bags and the cage, ensuring proper adhesion and a long service life. Quality filter cages are built to withstand cleaning cycles, bag changes, abrasive materials, high temperatures and many other environmental conditions they might encounter.

Additionally, filter cages should withstand the pressure exerted by the filter bag during the particulate collection cycle. They are also engineered to provide uniform support along the entire length of the filter cloth.

Regardless of design, each cage should adhere consistently to its specifications. This includes maintaining the correct diameter, total length, and other tolerances. The technologies we employ at Baghouse.com ensure your cages are made to spec, ensuring a proper fit between the filter bag and the cages and resulting in optimal cleaning performance. Our dust collector cages can be made to fit existing collectors from any baghouse manufacturers such as Astek, Gencor, Flexkleen, Mikropul, Wheelabrator, etc. We can also manufacture uncommon and specialized cage designs as required.

Understanding the Significance of Venturis

In some pulse jet collectors the venturi, or diffuser, plays a pivotal role. Its function is to accelerate compressed air at the center of the cage, optimizing the cleaning of bag filters. Venturis are made in a variety of materials including aluminum, carbon steel, galvanized and stainless steel.

Venturi Design

The venturi design changes the distribution of the cleaning pressure in the vicinity of the filter bag mouth, effectively reducing the energy consumption as well as reducing the dust emission concentration of the baghouse.

Why Choose Baghouse.com for Your Filter Cages and Venturis?

With millions of our cages installed and years of experience in the field, we confidently offer products that meet high standards of quality and performance. Our dedicated team efficiently manages projects from contract to design, construction, and delivery, anywhere in the world.

Investing in quality filter bag cages and venturi may not be the most exciting aspect of your dust collection system, but it’s undoubtedly one of the most critical. It ensures the longevity and effectiveness of your filtration system while reducing maintenance costs and noise in your facility. At Baghouse.com, we are committed to helping you achieve optimal filtration performance. Contact us today to find the perfect solution for your specific application. Your satisfaction and the efficiency of your operations are our top priorities.

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 Do Dust and Fume Collection Systems Work?

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Fume Sources

Dust and fume collection systems are indispensable in various industries, such as processes involving exhaust fumes from welding, sanding, grinding, spraying. Does your plant have any of these processes? If so, you must be interested in ensuring not only cleaner, safer workplaces but also compliance with environmental regulations. Among these systems, there’s one lesser-known hero: the ambient air collection system. In this article, we’ll explore how these systems function and their advantages.

Understanding Ambient Air Collection

At its core, an ambient air collection system is a type of dust and fume collection system. It operates by efficiently removing airborne particles from the atmosphere, making it an ideal choice for certain fabricating environments.

Cartridge collectors are commonly recommended for ambient systems due to their efficiency and compact design. These collectors use densely pleated filter cartridges with a high surface area, capable of handling substantial airflow. They excel at capturing even very fine fumes, up to MERV* 16, ensuring clean air. 

*MERV stands for “Minimum Efficiency Reporting Value.” It is a standardized measurement rating used to evaluate the efficiency of air filters in removing particles from the air as it passes through them. The MERV rating typically ranges from 1 to 16, with higher values indicating greater filtration efficiency. A higher MERV rating means the filter can capture smaller particles, including dust, fine fumes and other airborne contaminants.

The Difference: Ambient vs. Source-Capture

Ambient collection stands in contrast to source-capture systems, which rely on localized collection points like weld arms or fume hoods. Instead of capturing pollutants at specific spots, an ambient system continually exchanges all the air in a building or designated area.

Ambient systems offer several advantages over localized approaches:

  • Efficiency: Ambient systems are efficient, requiring less ductwork and power compared to localized systems with multiple capture points.
  • Cleaner Air: By removing dirty air from the entire workspace and returning it as clean, filtered air, ambient systems maintain overall air quality, even managing fugitive dust or fumes from portable sources.

    Modular Ambient Systems

    In variable production environments, a modular ambient dust collection system can be a smart choice. This approach involves using multiple smaller collectors instead of one large central system. It’s particularly beneficial for facilities with fluctuating production levels or plans for expansion.

    The experts at Baghouse.com can assist you in determining whether a modular or central ambient system is the right fit for your facility, considering factors like your current and future space usage and budget.

    Exploring Optional Functions in Fume Extraction Systems

    When considering fume extraction systems, you’ll encounter various optional features that can enhance their performance. These include:

    • Automatic Start-Stop Functionality: The automatic start-stop feature ensures that the fume extraction system operates precisely when needed. It activates as soon as the welding gun initiates an arc and includes a brief delay of usually 3 to 10 seconds after welding ceases. This thoughtful design not only conserves energy by preventing unnecessary blower operation but also contributes to lower maintenance costs and a quieter shop environment. Read more about Welding Safety Precautions.
    • Power Adjustment Capability: The power adjustment feature allows you to fine-tune the static pressure of your fume extraction system, aligning it with the specific parameters of your welding machine. Lowering the power not only reduces noise but also minimizes energy consumption. Additionally, it proves valuable in addressing rare occurrences like weld porosity or gas turbulence during welding. These events, while infrequent, are efficiently managed with this feature, ensuring your system’s readiness even when equipped with high-performance fume extraction equipment and welding guns.
    • Automatic Cleaning Functionality: Automatic cleaning is a smart feature that enables the system to self-clean the filter when a certain level of dust accumulates. This process can be based on a timer or triggered by monitoring the actual static pressure against the preset power of the unit. Importantly, this self-cleaning process occurs seamlessly while the welder continues to work.
    • Shunt Alarms: Shunt alarms provide clear signals, often through lights or gauges, indicating the need to replace the filter. This feature can be integrated into a fume extraction system equipped with automatic cleaning or used with systems featuring replaceable filters, ensuring you stay aware of filter maintenance requirements.

    How Baghouse.com Can Assist You

    At Baghouse.com, we specialize in dust and fume collection systems tailored to your unique needs. Whether you’re considering an ambient air system or another solution, our experts can guide you through the entire process. From system design to installation and maintenance, we’re here to ensure your workplace remains clean, safe, and compliant.

     

    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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Which Baghouse Hopper Discharge Method Is Best?

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6 baghouse hopper dust discharge styles

Many problems arise over how to properly dispose of dust in the baghouse once it is collected. Improper dust disposal can directly impact the operation of your baghouse. Storing dust in your baghouse hopper is a terrible idea. Dust collector hoppers are designed for temporary storage only. If collected dust builds up in the hopper it can cause several problems.

  1. It directly causes filter bag abrasion, the wearing holes near the bottoms of the bags. This happens because the rising dust levels disrupts the carefully engineered airflow mechanics within the baghouse. When high speed air is pulled across the surface of a pile of dust in the hopper it picks the dust back up (i.e. dust reentrainment) and essentially throws it back at the filter. The effect is much like sandblasting your filter bags, something no bags will ever be able to withstand.
  2. Large amounts of dust can provide ample fuel for fires or even combustible dust explosions. Sparks and embers can make their way into the unit from cutting, grinding or other friction generating processes as well venting of furnaces and other heat sources. These ignition sources can ignite bags upon reaching the baghouse or pass through to the hopper. In either case, large amounts of dust in the hopper provide ample fuel for continuing a fire or making it much worse.
  3. Excess hopper buildup will block off the baghouse and cause a loss of suction throughout the system. Loss of suction at pickup points can shutdown entire plant processes, damage equipment and even cause environmental safety hazards and increase emissions levels past permissible limits.

Clearly, failure to keep the discharge working efficiency can have serious consequences. So how can you make sure your discharge system meets the needs of your baghouse?

 

6 baghouse hopper dust discharge stylesDifferent Baghouse Discharge Systems

Let’s review a few common dust discharge methods and some guidelines for choosing the best option for your application.
#1, 3 – Covered Box or Drum with venting
An enclosure (usually a box or container) directly underneath the discharge holds the dust. To prevent dusting and back pressure issues the enclosure is vented by (a) a small vent with filter attached to it or (b) with a duct vent piped back to the collector or the inlet duct. Simple system, but requires maintenance to remove collected dust or else it can backup into the discharge (blocking the system) and overflow the container. Good for systems with light dust loads and nonhazardous materials.

#2, 5, 6 – Removable Storage Containers
Uses drums or bags to collect dust from discharge. When filled, technicians remove them by hand or using a forklift for disposal and then replace them with a new container. Good choice for easily handled, non-toxic dusts. Can also be useful for products that then get shipped by truck from plant (e.g. fly ash sold to cement plants, etc.) Requires technicians to monitor fill levels and replace as needed.

A dust transport method for baghouse discharges is by screw conveyor

The most common automated dust transport method for baghouse discharges is by screw conveyor

#4 – Discharge to conveying system
Preferred where possible, this method ensures the prompt removal of discharged dust. This proves the best solution for large units with heavy dust loads and applications requiring dust to be transported far from the collector after disposal such as hazardous material disposal, or for reuse in process. On the downside, it is more expensive than other methods and requires additional maintenance costs to maintain system.

Conclusion

We have seen that the best method of hopper discharge varies from application to application and from unit to unit. However, this does not mean that all discharge methods work for all baghouses. As outlined above, serious problems arise when the baghouse hopper discharge system is not adequate to the dust loads passing through the unit. Additionally, the disposal methods may require more man power than available at the plant and lead to spillage and other issues.

These issues can be avoided by not leaving the dust discharge method to chance. Review the operating parameters, dust loading rates, dust characteristics and eventual use of the dust (including disposal in landfill) before selecting a discharge method.

Baghouse.com has helped many plants retrofit their existing dust collectors with new hopper discharges, dust transportation and removal. Contact us today and let us advise you on how to improve your discharge system and thereby improve your dust collector efficiency today!

Need Help With Your Hopper Discharge?

Baghouse.com has helped many plants retrofit their existing dust collectors with new hopper discharges, dust transportation and removal. Contact us today and let us advise you on how to improve your discharge system and thereby improve your dust collector efficiency today!

Contact Us Today!
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FAQs – Dust Collection System Design and Operation

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Dust build up inside a duct connected to a dust collector

Question: What is “normal” differential pressure in a baghouse?

Answer: In most applications a baghouse dust collector should run between between 3″ to 6″ w.g. under normal use. Once levels rise above 6″ (roughly) and the cleaning system cannot return it any lower (even when turned to continuous cleaning or “Test” mode) it is a sign that the filters are beginning to be blinded and likely need to be changed. It is not advisable to run a baghouse with a DP higher than 6″ for any length of time as this will have an impact on the function of the entire system. Running at such a high DP will lead to a number of problems including vacuum loss at the pickup points of the system (loss of suction), lower air speeds in the ductwork, higher emissions, and higher energy usage.

If you are seeing levels below 3″ after having run the baghouse for sometime you liking are getting false DP readings. When brand new bags are installed in a dust collector they should provide approximately 1″ of resistance alone. Once they begin to load dust that number will rise to between 2″ – 3″ no matter how much you clean them.

A clean on demand baghouse controller (i.e. clean on pressure) is the best way to keep a dust collector running in the recommended DP range. (see article: 3 Cheap Ways to Increase Efficiency in Dust Collection Systems)

Dust build up inside a duct connected to a dust collector

Maintaining the minimum conveying velocity in the dust collection system prevents dust drop out and build up inside the ductwork

Question: What is minimum conveying velocity in my baghouse and why is it important

Answer: The minimum airspeed required to keep dust particles suspended in the conveying system (i.e. dust collection system). When the air in any part of the dust collection system slows below the minimum conveying velocity the dust will begin to drop out of airstream and settle to the bottom of the ductwork (known as product drop out).

Maintaining the airspeed throughout the system above the minimum conveying velocity is required to prevent the accumulation of dust in the ductwork. Overtime, dust can accumulate into large piles, eventually blocking off part of the ductwork and reducing suction downstream in the system, further compounding the problem. Blockages can also cause the passing airstream to accelerate (forcing same air through a smaller space) that can lead to abrasion issues and eventually wear holes into the ductwork. Large accumulations of dust can eventually collapse sections of the ductwork due to the added weight.

Preventing product drop out is even more serious in applications involving combustible dust. Any accumulations of dust within the ductwork provide a potential fuel source for any ignition source that may find its way into the ductwork such as sparks. Additionally, if a fire starts in one part of the system it could continue to propagate throughout the rest of the system being fed by the accumulations in the ductwork. Further, if the system is operating below capacity due to blockages, dust may accumulate elsewhere in the facility including on elevates spaces that can then become fuel for both primary and secondary dust fires and explosions.

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FAQs – Dust Collector Filters

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Question: Why are my baghouse filters so expensive to replace?

Answer: Many simply buy their replacement filters from the OEM or sales rep that supplied their baghouse. Often times, manufacturers and sales rep organizations deliberately sell their units cheaper and then make convince their customers that they are locked into using a proprietary filter design that only they can supply and thus they charge outrageously high prices for them. Other times, they convince their customers to use an outdated or rarely-used technology so hard to find form other manufacturers that it nearly guarantees them your repeat business for replacement parts. This is common with many cartridge collector OEMs, whereby they win the initial unit sale by undercutting other manufacturers (often by recommending a undersized dust collection system) and then plan on making their profit on the expensive replacement filters later on. This marketing technique is commonly called the “razor blade” system, for its well-known use by makers of disposable razors and cartridges.

Need New Filters?

We offer replacement baghouse filters, cartridges, and pleated filters for all makes and models of dust collectors, including the most popular brands Farr, Donaldson / Torrit, Wheelabrator, and more. Often we can offer significantly better prices than buying from the original dust collector manufacture, sometimes as much as 50% less! If you do not believe us, give us a try and let us give you a quote for your next set of replacement baghouse filters.

Get Your Quote Now!

Question: How long will my baghouse filters last?

Answer: Baghouse filters have an average service life of 1-3 years in most applications. Some can go beyond that without major increases emissions, while others may last less than a year in more difficult applications. The main reason to replace baghouse filters is because when old they begin to leak and thus the system is no longer collecting particulates as its designed to do. Filters can also be damaged prematurely by sparks/embers that can cause fires or even explosions. Upset conditions in the process may cause a spike in temperature (beyond the maximum for the filter fabric) or may create an acid flash or similar chemical attack on the bags. Finally, bags may be damaged during maintenance or by other external forces.

The main signs that your filters need to be replaced are that they are can no longer be cleaned effectively by the baghouse and/or they start leaking.

Baghouse filters that are blinded

Blinded filters must be replaced.

Question: What does it mean when my baghouse filters are “blinded”?

Answer: Blinded filters means the filters are so loaded with dust that they can no longer be cleaned by the baghouse cleaning system and must be replaced.

During normal operation dust particles accumulate on the surface of the filters and form a dust cake, which is then cleaned by the pulses of compressed air during the cleaning cycle. Overtime, some dust particles pass through the surface layer and become embedded deep within the fibers of the filter fabric where it cannot be removed by the cleaning pulses. Eventually, the fabric becomes so filled with dust particles that it severely restricts the movement of air through the filter. When this occurs the filter is said to be “blinded”.

When a baghouse can no longer clean itself down to a lower DP range (e.g. below 6” of DP) even with constant cleaning (i.e. continuous cleaning mode or test mode) it is likely that the filters are blinded and must be replaced.

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FAQs – Baghouse Controls and Cleaning Settings

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a baghouse dust collector control board
a baghouse dust collector control board

With Clean on Demand Controllers  the “On-Time” setting  must be set correctly or else bag cleaning will suffer. On on Turbo baghouse controllers (and on many others) you need to first find the preset that corresponds to the on-time setting (here shown as F1), push select, and then enter the proper value (.1-.15 ms)

Question: What does the “On-Time” setting on my baghouse control board do?

Answer: On-Time determines how long the pulse valve is open for during a cleaning cycle. This setting is VERY important for proper cleaning of the baghouse filters on a pulse jet dust collector. If set too long then the air pulses will be weak and waste compressed air, lower pressure in the air header (causing delays while it builds back up or weakening the following pulses) or even damage the filters. If set too short not enough air volume will be released to clean the entire bag. It will also cause uneven dust loading on the bags, which in turn can cause a long list of problems in the collector.

Question: What should I set as the “On-Time” on my baghouse control board?

Answer: As a general rule, this should be set to between .01 – .015 ms (milliseconds). For certain specific applications (such as pleated filters, or certain “sticky” dusts) your dust collector OEM might provide you with a slightly different setting.

Question: What is clean-on-demand and why should I use it instead of just setting a timer?

Answer: Clean on demand (or clean on pressure) is a means of controlling a pulse jet baghouse cleaning system. It is the most effective way to operate your dust collector and it can lead to considerable savings in several areas.

Using a clean on demand baghouse controller, operators set high and low differential pressure points (usually 5.5″ and 3″ respectively). When the DP reading hits the high point the control board begins firing the pulse valve(s). It will continue firing them in order until the DP drops below the low point.

In contrast to a simple timer board, a clean on demand controller only cleans the bags only when necessary to maintain stable operation. This prevents over cleaning (which increases wear and produces higher emissions), reduces compressed air use (costly in most plants), and reduces wear on the diaphragm valves. Additionally, clean on demand controllers are able to adapt to changes in dust loads (common in most applications) something timers cannot do.

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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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