Skip to Content
Exit

Tag Archive: Dust Collector Design

  1. Baghouse vs Cyclone Dust Collector

    Leave a Comment

    Choosing the Right Dust Collection System

    There are two common approaches for using cyclone dust collectors, as a stand-alone system or as a pre-filtration unit paired with a larger dust collector. This article includes information on:

    Understanding these variables can help you identify whether a standalone cyclone system is best for your application or if you need to pair your cyclone with a larger dust collection system.

    US Air Filtration Baghouse Dust Collection System

    How Does a Cyclone Dust Collector Work?

    Cyclone dust collectors are small-scale stand-alone units that work to remove large dust particulates from the air using centrifugal force. The filtration process starts with dirty air being drawn into the cyclone dust collection system at a high speed. This high-speed motion works as a controlled “hurricane” inside of the cyclone. The “hurricane” motion allows larger particles to be pushed out and up against the cyclone walls. Then once the dirty air hits the walls of a cyclone, momentum slows down, which is enough to permit larger particles to drop out of the airstream and into a hopper beneath.

    Dust Characteristics, Capacity, CFM, and Cyclone Dust Collectors

    Understanding your Dust characteristics is the first step to understanding whether you need a baghouse, cyclone or both? 

    Cyclone dust collectors are ideal for applications dealing with large, coarse dust particulate. If your application contains a mixture of large and small dust particulate, you’ll likely need tofilter larger dust particulate out first with a cyclone and then direct the remaining gas stream to a larger baghouse that uses filters to handle finer particulate. This two-step filtration process helps prevent large particulate (e.g., wood chips) from creating unnecessary wear and tear on baghouse filters.

    Beyond dust characteristics, dust loading rates and CFM are factors when considering which dust collection system is best for a specific application. Because cyclone dust collectors are small-scale units, their capacity to handle dust particulate is finite. General dust loading rates can be between a 5-to-30-gallon drum. In terms of CFM, most cyclones operate anywhere around 1000 CFM or below.

    Baghouse Dust Collector for an Industrial factory

    Common Applications for Cyclone Dust Collectors

    Applications for Stand-Alone Cyclones:

    • Woodworking applications with only large dust particulate 
    • Agricultural applications with only large dust particulate

    Applications for a Baghouse or Baghouse and Cyclone System:

    • Woodworking (all)
    • Agricultural (all)
    • Mining & Minerals
    • Recycling
    • Pharmaceuticals
    • Paper Products
    • Chemicals
    • Rubber Plants
    • Food Manufacturing
    • Bulk Powder
    • Industrial Equipment and Machinery
    • And More!

    Food on a conveyor belt at a food manufacturing plant

    Advantages and Disadvantages of a Cyclone Dust Collector

    Cyclone dust collectors  are designed as a simple steel structure with no moving parts or filters. Because of this simplicity, the main advantages and disadvantages are:

    Advantages of a Cyclone:

    • Low up-front investment. There are a wide variety of models, but generally you can find a cyclone dust collection system ranges anywhere from $500-$3000.
    • Long-term cost savings on maintenance and repair
    • Paired with a larger baghouse, can increase the efficiency and life of filter bags or cartridges

    Disadvantages of a Cyclone: 

    • Low dust loading rates
    • Limited CFM capabilities
    • Low efficiency at capturing fine particulate
    • Unable to process sticky materials 
    • Application use is limited

    Benefits of a Cyclone with a Baghouse Dust Collection System

    In specific cases, an engineer may determine that your plant can benefit from pairing a cyclone with a larger dust collection system. Typically, processes that have a mix of large and small particulate are the ideal candidates for this type of setup. 

    A cyclone could be implemented as a pre-filtration system to eliminate any large, coarse particles that could damage a dust collector’s filter bags or cartridges further downstream. The result is an increase in the performance of a dust collection system and the service life of the baghouse filters. In certain cases, cyclones can also help to reduce dust loading into a baghouse with a high inlet entry. This method reduces internal velocities (e.g., can velocity) resulting in improved efficiency and increased filter life.

    To determine whether your application would benefit from a combination cyclone and larger dust collection system, some questions you may be asked include:

    Questions to Consider:

    • Do you have a dust analysis or DHA (dust hazard analysis)?
    • What’s the size of your particulate? Is it big? Small? Mixed?
    • How much dust are you filtering out in a given work shift?
    • Could your dust collection design incorporate an end inlet as an alternative? While there is no cyclonic action with an end inlet, the attributes are similar. An end inlet helps bring in the dust high, but as it hits a baffle, it redirects the air directly downward. In this scenario, heavy particulate hits the baffle, then slows down and drops out. Then rest of the air is kicked down below the bag, allowing your system to still have can velocity. The disadvantage to an end inlet is these types of baghouses tend to be considerably larger because there must be space for air to hit the baffle.

    Even in similar industries, plants will have different requirements and variables from one another that will determine the right dust collection solution. To get beyond the basics, we recommend speaking to an engineer who can help with your specific application and needs.

    Conclusion

    To summarize, cyclones are limited in their capabilities. In certain conditions you could add a cyclone to be helpful and reduce dust loading on larger systems, but cyclones alone are not typically adequate for most industrial applications. At U.S. Air Filtration our engineers can help determine if the dust collection system you’re looking for would benefit from adding a cyclone. Our goal is to do what we can do to help save you costs, while also ensuring we are designing a solution that will perform long term.

  2. High Inlet versus Low Inlet Baghouse Design

    Leave a Comment

    A critical part of the dust collection design process is where to position your baghouse inlet. The purpose of the baghouse inlet is to draw dirty, dust laden air into the system so the air can be filtered.  In this article, we will focus on the design factors that help determine a system’s inlet placement (high versus low), can velocity, and the advantages of a high inlet versus a low inlet baghouse.

    Dust Collection System Design Factors

    When designing a dust collection system, we consider your dust properties and the characteristics of your work environment carefully to identify the best solution.  Below are the five most critical dust collection design elements.

    Dust Collection Design Factors

    During the design process, we consider two primary characteristics that influence baghouse inlet placement:

    • The amount of dust you are bringing into the collector
    • The heaviness of the dust

    When you have a large amount of dust and that dust is heavy, a dust collection system may benefit more from a low inlet design. When heavy dust enters the unit at the bottom of the system, the natural force of gravity will pull the dust down. Conversely when you have light to medium dust loading and very light dust, a dust collection with a high inlet design would typically be best.

    However, even in similar environments the dust loads, work environment, and space can vary drastically. Our best recommendation is to work closely with your U.S. Air Filtration equipment specialist. Understanding all the details and nuances to your specific project will allow us to make the best design recommendations.

    Dust Collection Assembly

    Can Velocity and Dust Collection Design

    Can velocity is the speed at which air moves from low in the baghouse to high. The higher the can velocity, the faster air moves up in the system.  We calculate can velocity based on your CFM, the size of the collector, and your space restrictions.

    During the design process, your equipment specialist can help determine if there will be a high enough can velocity that would require a high inlet. A high inlet will eliminate or counter can velocity. This way, dust can drop or if the dust is heavy enough, the dust will overcome upward air movement and drop out without issue.

    CFM, space restrictions, and dust loads are all straightforward questions. But depending on the answers provided there can be different results. Here are two different scenarios that could occur during the design process that require two different inlets.

    Baghouse Inlet Scenario 1:

    • No design preference for the inlet.
    • No space issues
    • In this case, it’s possible for a customer to have a system that’s designed to hold 700 filter bags, 8’ in length, with a low inlet. This scenario is possible with just about any type of dust. All that is needed to drive that air to cloth ratio down as low as possible, is to eliminate as much can velocity as you can. As a result, your dust collection system will work as intended with a low inlet design

    Baghouse Inlet Scenario 2:

    • No design preference for the inlet.
    • Yes, there are space constraints.
    • In this example, if there is only a 15’ by 15’ space to install a dust collection system, the system must be taller and require longer filter bags of 12’ to adequately handle the dust load. filter bag. By design, there will be a much higher can velocity even though the same air to cloth ratio is being used. This is because the filter bag is longer, the dust collector is thinner, more vertical rather than wider, and shorter. These factors all increase can velocity. Because the can velocity is higher, a high inlet would be required to allow better dust dropout.

    High versus Low Inlet Dust Collector Design Advantages

    When considering a high versus low inlet for your dust collection system, there are certain design advantages that are considered based on dust type and application. There are additional costs for a high inlet baghouse. If your project will allow for a low inlet design, then that’s the route we recommend. Our goal is to help you avoid spending more money than necessary both upfront and in long term maintenance costs.

    However, in certain situations it may be worth investing in a high inlet.  These situations include:

    • When you are worried about the dust not dropping out of the airstream
    • If you’re concerned the bags won’t clean properly
    • If you are afraid you are going to lose suction over time

    In these cases, it may be worth spending the extra money to design a dust collection system with a high inlet, to avoid these issues. You will also have the added benefit of avoiding additional maintenance problems down the road.

    Baghouse Design

    Additional Baghouse Inlet Options

    What if your application has light dust, but high dust loading? An additional option in this case would be an end inlet. This helps bring in the dust in high, but as it hits a baffle, it redirects the air directly downward. In this scenario, heavy part particulate hits the baffle, then slow down, and drop out. Then it kicks the rest of the air down below the bag, so you still have can velocity. However, we reduce the amount of dust in the airstream so much that can velocity is not as much of a concern as if it was just a standard low inlet baghouse. The disadvantage to an end inlet is those baghouses tend to be considerably larger because you must have space for that air to hit the baffle.

    The Design Process with U.S. Air Filtration

    Baghouse Design

    At U.S. Air Filtration, our V.P. of Engineering, generally recommends a low hopper entry or side entry inlet baghouse with a full blast height plate/drop-out box plenum, if the particulate from the process is highly abrasive and/or has a bulk density of greater than 70 lbs./CF. (I.e., Sand, silica, glass, etc.) If you have questions regarding this exception, please contact U.S. Air Filtration’s engineering department for further explanation.

    At U.S. Air Filtration, we understand that a dust collection project may just be one piece of a larger project for you. Our engineers are here to help solve your concerns and design a solution that best fits your application and facility. If you need to speak with an equipment specialist, please feel free to contact us at 888-221-0312 or email [email protected]. If you’re just starting your dust collection project, access our “Dust Collector Purchasing” article for more information on design considerations, airflow, air-to-cloth ratio, and more.

  3. Guide to Calculating Dust Collection CFM

    Leave a Comment

    CFM is a measurement of airflow related to air conditioning, heating and ventilation environments. In dust collection applications CFM measures the amount of air per minute that can be moved from a space.

    If you’re not familiar with how to calculate dust collection CFM, the process can be intimidating. In this article we will help you understand our approach to calculating CFM requirements for you. Along with the questions you should be asking your dust collection engineering firm to identify the optimal solution for your plant.

    Dust Collector Purchasing Guide

    Dust Collection CFM Questions to Consider

    • Where is your dust being created?
    • Are you using taps or hoods at the points of dust creation?
    • What type of dust are you working with?
    • What are your dust characteristics?

    One of the first questions we ask is, “Where is your dust being created?” This allows us to understand where your pick-up points are, and how many of those need to factor in when calculating your CFM.

    Methods of Dust Collection

    How Much Does a Dust Collector Cost

    Once we understand where the dust is being created, then the next question becomes, “What’s the best way to collect the dust at that dust creation point?” Three common methods are:

    1. Tap
    2. Hood
    3. Articulating Arm

    Many facilities include source taps at every machine. If there are no taps, then a hood or a smaller pickup point can be added. For example, a hood can be added above a table to capture dust if there is a need to constantly maneuver around the table.

    If there is movement happening around the machine in different ways (e.g., leaning over a machine) then there may be a need for an articulating arm. An articulating arm allows a way for the hood or pick up duct to be as close as possible to the actual creation of the dust. As U.S. Air Filtration helps you calculate the right CFM, we will work together with you to gather these details machine by machine.

    What’s Needed to Calculate CFM?

    You may not know the CFM you need, but here are the things you can provide that will allow us to help solve that for you.

    • How close can we get to the machine?
      • For example, if the machine has a six-inch tap, then we would know that would require a six-inch duct. Generally, when the machine is designed, your pickup points are also designed with the intention to efficiently capture dust.
    • Blueprint of your facility or a roughly drawn layout
      • This helps us understand the distances between the machines, walls, and where the dust collection system will be placed.
    • Photos of your machines. This helps us identify if you are using taps or hoods.
      •  Tap
        • If there are no taps, how are people using the machine?
        • Is the machine stationary?
        • Does someone need access 360 degrees around the machine?
      •  Hood
        • If there are no hoods, what is the size of the machine or table that’s creating dust? This helps us properly size a hood and with those dimensions we can look at velocity at the hood.

    Then, depending on the weight of the dust, we get a better understanding of the specific velocity needed to move the dust and the duct size that’s required. These two factors together can help us get to the right CFM for your dust collection project.

    Dust Collection Source Capture versus Room Capture

    Dust Collection CFM

    In the case of a grinding application, you may do all your grinding in one room and want to ventilate the entire room itself.

    While the initial calculations and process to ventilate one room may seem easier, it’s not necessarily the best in terms of cost. Our recommendation is to get as close as you can get to the source of the dust, which allows you to move less air. This can mean a smaller system, which can lower the price tag of your project while also capturing dust more efficiently.

    For an everyday example, let’s say you have dust all over your kitchen floor and you don’t want to vacuum every square inch of it. Then your option would be to try and suck the dust up through a hood. That requires you to pull a large amount of air very quickly, which in turn requires much greater force from the fan to capture the dust. In contrast to that, if you have a vacuum and a hose, then you can pick up everything closely using a very small amount of air and suction requirements.

    While it may be tempting to “just ventilate the room”, keep in mind that every CFM comes with a price tag. Moving 100,000 CFM versus 10,000 CFM is going to be more costly. The details that go into calculating your CFM may be cumbersome at first, but it will save you from spending a considerable sum of money in the long run.

    Negative Impacts of Miscalculating CFM

    The Dangers of an Undersized Dust Collector

    When designing a dust collection system, it’s best to err on the high side of CFM rather than the lower side. It’s very difficult is to make a dust collection system larger once it’s in place. It’s much easier, if necessary, to damper the fan down or add a smaller fan.

    Correcting for a larger than needed dust collection system involves adding more filter media. Upfront costs are slightly higher, but your system will work well, and you’ll be able to remove dust out of the way as you intended. The reverse isn’t true. If your system is too small, it’s very difficult to add filter media. Getting the dust out of your facility will always be an uphill battle. So, to reiterate when in doubt error on the high side.

    • If you underestimate CFM, you won’t capture the dust that you need to capture.
    • The system will not work the way it was designed. Therefore, you will spend a large sum of money on maintenance expenses due to increased wear and tear..
    • If you overestimate CFM, the dust collection system will work just fine, but long term you will pay 20%-30% more for a system.

    Advantages of Working with USAF

    U.S. Air Filtration Dust Collection Engineering

    One of the advantages of working with U.S. Air Filtration is that we have a team of engineers with over 40 years dust collection experience who can gather the details you provide and calculate the numbers to get you to the right CFM.

    Calculating CFM and designing a system is a complex engineering process.  We do all the leg work for you, so you don’t have to.

    If you would like to speak to an engineer about your specific project, contact us at 888-221-0312 or email [email protected]

  4. How to Select the Right Dust Collector Filter Bags

    Leave a Comment

    To download a free PDF version of this Dust Collector Filter Bags Guide simply click this link here.

    Choosing the right filter bags for your dust collection system is critical to ensuring long term, reliable performance of your collector and the safety of your employees. Our guide will help you understand your facility’s unique dust properties and provide an overview of various filter media, construction, and treatment options available.

    We’ve organized our dust collector filter bags guide into these key topics:

    Top Factors to Consider for Dust Collector Filter Bags

    1. Understanding Your Dust Properties
    2. Dust Testing
    3. Common Filter Media
    4. Filter Bag Finishes
    5. Filter Bag Construction
    6. Air-to-Cloth Ratio
    7. Additional Resources

    Understanding Dust Properties

    Understanding Dust Collection Dust Properties

    Choosing the right filter media for your dust collection system is critical to achieving peak performance while reducing system wear, plant downtime, and extending filter life. The first step is to consider the properties of your dust particulate and review the following:

    • Product – What  you  are filtering?  Does your product contain a moisture or oil? Products with moisture content greater than 25% are not suited for a dry dust collection system (baghouse, cartridge collector or bin vent). Products containing hydrocarbons, including oils, may require the application of special treatment to your filter media for optimal
    • Temperature – What is your typical operating temperature? Max temp? Media temperature ranges for dry dust collection can typically be sorted into three categories listed below:
      • < 275°F – Polyester filter media performs very well for ambient airflow temperatures in this range.
      • Between 275°F and 400°F – Aramid filter media is the optimal choice for temperatures in this
      • Between 400°F – 500°F – Fiberglass filter media is the most economical option for high-temperature applications; however  depending  on the type of dust, another filter media may be a better

    Once you understand the temperature of your work environment, you can narrow down your filter media options and in many cases, apply a special treatment to the media to further improve performance. Treatment application can be an efficient way to minimize costs before considering a more expensive filter media.

    Chemistry

    Does the airstream or dust contain chemicals that could damage the filter media? Are their acids or alkalines in the airstream? Often when certain compounds are combined during processing, a chemical reaction can occur, which may require a specific media treatment or coating on your filter bags to protect the bags from accelerated wear.

    Abrasion

    How abrasive is the dust being filtered? Consider the hardness of the material that’s being filtered along with the shape of the dust. The velocity of your airflow can also make your dust more abrasive. If you are designing a new dust collection system, it’s important to engineer the ductwork, fan size, and unit placement to ensure the airstream is not entering your dust collector too quickly or too slowly.

    Particle Size

    What size dust particulate are you collecting? Depending on your emissions requirements, your application may require a special membrane. This will apply if your particulate is very fine.

    Is Your Dust Combustible?

    Combustible dust can be defined as any fine material that has the ability to catch fire and explode when mixed with the proper concentration of air. Examples of combustible dust include wood , food products such as grain, sugar, flour, starch, metals, rubber, chemicals, pesticides, plastics, and more. To protect your plant and your employees from the risks of a serious explosion, carefully consider OSHA and NFPA guidelines and be sure to review your state and local regulations for proper identification and management of combustible dust.

    OSHA Standards

    Implement and maintain OSHA’s set of standards regarding combustible dust. When you adhere to OSHA’s set of standards, you are creating a safe work environment, avoiding property and economic loss from an explosion, and avoiding regulatory fines.

    NFPA Guidelines

    Make sure you are meeting codes outlined by the NFPA (National Fire Protection Agency) . The NFPA publishes a list of guidelines that will help you minimize injury or death from combustible dust. The following regulatory codes are related to the most combustible types of dust (e.g., sugar, wood , fine aluminum):

    • 664, Standard  for the Prevention of Fires and Explosions in Wood Processing and Woodworking Facilities
    • 484, Standard for Combustible Metals
    • 61, Standard for the Prevention of Fires and Dust Explosions in Agricultural and Food Processing Facilities

    Dust Testing

    Dust Collection Dust Testing

    Dust testing may also be performed to assess the properties of your particulate and ensure proper filter selection and performance. This option may be ideal for new facilities and large applications . If you have an existing plant and many of your filter bags have failed prematurely with no consistent pattern, and there are no signs of workmanship  error, it  may be necessary to perform laboratory testing to find out if changes in the airstream could be compromising the bags.

    Common Filter Media

    Common Baghouse Filter Media

    Polyester

    Polyester media is an economical option with excellent filtration properties and is widely available. This makes polyester the most common filter media used across many industry applications. Polyester has an operating temperature limit of 275°F and comes in both needled felt and woven medias. Both needled felt and woven polyester  can  be treated with several finishes and membranes  to  increase the efficiency and filter bag performance in varying operating conditions.

    Aramid

    Aramid, also known as Nomex, is used in applications with high temperatures and has excellent filtration and abrasion properties. The operating temperature limit for aramid is 400F which makes it a  great choice for applications such as asphalt batch plants, furnaces, and dryers. Both needled felt and woven aramid can be treated with several finishes and membranes to increase the efficiency and filter bag performance in varying operating conditions.

    Fiberglass

    Fiberglass is often used in baghouses with temperatures ranging up to 500°F. Since fiberglass media is typically woven, the efficiency of a plain fiberglass media is lower than most felts. However there are several different membranes and finishes that can be added to fiberglass to increase filter efficiency and performance in harsh baghouse conditions. These finishes and membranes make fiberglass a versatile media for  applications  with high temperatures. You’ll see  Fiberglass  media used in industries such as energy, cement/ concrete/aggregates, and agriculture. Different membranes, coatings and finishes can be added to fiberglass media to increase performance in certain applications. This makes fiberglass a versatile media for applications with high temperatures.

    P84

    P84 media has a high temperature rating of up to 500°F. This filter media handles acids better than fiberglass and also results in less abrasion to the filters due to filter media flex.

    Teflon (PTFE)

    Teflon (PTFE) is one of the highest performing filter medias available for  a wide range of applications and is also the most expensive. It bears well against chemical and acid resistance, high temperatures, and moist heat. Teflon membrane can also be applied as a treatment on other filter medias to further extend filter life and reduce system wear.

    For more information on other media types in the dust collector industry (e.g. PPS, Acrylic, and Polypropylene) access our Fabric Characteristics Chart below.

    Dust Collector Filter Bag Characteristics Chart

    Filter Bag Finishes

    Filter Bag Finishes

    Benefits of Filter Bag Finishes

    • Lengthen the life of your filter bag
    • Better dust cake release (reduced valve pulsing = reduced compressed air consumption)
    • Achieve more consistent airflow
    • Reduces downtime and maintenance

    Filter media fabrics can be made from both natural and synthetic fibers, although synthetic fibers are more common today. As we have seen in the previous section, different fibers provide each media with different  performance  characteristics. Most medias today are pre-shrunk and include  some type of finish to improve media performance.  Finishes for felt and woven bags can be different as we will see below.

    Napping

    This process is the scraping  of  the  filter  surface  across  metal points  or burrs on a revolving cylinder. Napping raises  the  surface  fibers,  creating  a  “fuzz”, that provides a large number of sites for particle collection by interception and diffusion. Fabrics used for collecting  sticky or oily dusts are sometimes  napped so they can provide better collection and an easier cleaning process.

    Coating

    Coatings , or resin treating , involves  immersing the filter  material in a resin which can add certain characteristics to the filter media. For  example,  fiberglass threads can be coated with Teflon to prevent abrasion during bag cleaning and silicon graphite to aid in acid resistance.

    Filter Bag Construction

    Filter Bag Construction

    The construction of your filter bags is dependent on your baghouse style, application, and other requirements specific to your facility. Below is a brief summary of how each type of baghouse works.

    The three main baghouse styles available include:

    • Pulse jet
    • Reverse air
    • Shaker

    In each baghouse style there are a variety of filter top and bottom configurations that can be used. Some top and bottom configurations are meant for a specific baghouse style, and other configurations can be used across multiple baghouse styles.

    Pulse Jet

    Pulse jet baghouses collect dust on the outside of the filter and clean filters from the inside out with a jet or pulse of clean air. Dirty air enters the baghouse and is forced to pass through the filter bags to exit the baghouse. As air pass through the bags, dust is filtered out and collects on the outside surface of the filter bags. This buildup of dust on the outside of the filters is known as a “filter cake.” The filter cake aids in filtration by trapping smaller particles as the dirty air passes through the filter cake and bag. Pulse jet baghouses offer a wide range of filter media, making it an excellent fit for most applications.

    Reverse-Air or Shaker

    In a baghouse using reverse air or shaker cleaning systems, the particulate is collected on the inside surface of the bag. The dust-laden gas enters the dirty side (inlet) of  the  collector  and  flows up through the bag. The particulate is filtered by the dustcake and the fabric, and clean air exits through  the outside of the  bag.  Shaker and reverse  air bag top and bottom designs vary by cleaning system and original equipment manufacturer.

    Reverse air and shaker style baghouse both collect dust on the inside of the filter bag. Reverse air baghouses reverse the flow of air through the baghouse in order to clean the filter bags while  shaker style baghouses clean the filter bags by moving them back and forth in a shaking motion. The buildup of a filter cake is important with these style collectors as it greatly aids in filter efficiency.

    Both pulse jet and reverse air/shaker style baghouse come in a number of different bag constructions and understanding the requirements of your specific baghouse is important to ensure proper filter bag fit.

    Air-to-Cloth Ratio

    Air to Cloth Ratio

    Dust collector air-to-cloth ratio is a critical measure to ensure your collector is performing efficiently.

    Air-to-cloth ratio, also known as air to media ratio, is a measurement of the number of cubic feet per minute of air passing through one square foot of filter media.

    Generally, a lower air-to-cloth ratio, the more effective your system is at removing dust from the work environment. When determining an appropriate air-to-cloth ratio, there are several factors to consider, including application, type of dust, moisture levels, inlet loading, etc. If the air-to-cloth ratio is higher than recommended, some common issues can arise, including increased differential pressure, frequent filter changeouts, and varying or reduced suction at pickup points. These issues are a result of not having enough filter media to handle the air flow and dust load effectively. As the dust cake builds on the filters, the airflow is restricted and slows, resulting in a decrease in air velocity and suction. From there it becomes a domino effect: air quality decreases, filters clog quicker requiring more changeouts, pulse valves see increased wear, and facility production may be impacted.

    Why is the right Air-to-Cloth ratio important?

    • Ensures dust collector is running efficiently
    • Minimizes operating costs
    • Maximizes filter life
    • To meet air quality goals and requirements

    What are the negative effects of an improper Air-to-Cloth ratio?

    • Increases maintenance which can impact production
    • Reduced air velocity resulting in poor ventilation at pickup points
    • Increased compressed air consumption
    • High differential pressure and increased system wear

    Download the chart below for a summary of recommended Air-to-Cloth ratio for a variety of industrial applications.

    Air to Cloth Ratio Chart

    Dust Collector Filter Bags Additional Resources

    Filter Bag Media Quiz

    Finding the right filter bag can be overwhelming, confusing and time consuming. There are so many options and it’s hard to know which  will work best for your application. Or if there is a better option out there that will get you better performance.

    To get you to the right solution, take this interactive filter media quiz. You’ll immediately receive:

    • Recommendations on the best filter media options for your unique application.
    • Filter media characteristics chart with media specs and pricing.
    • No obligation price quote for your filter media within 24 hours.

    Dust Collector Filter Bags Media Quiz

    Selecting the right dust collector filter bags will keep your employees and your operation safe and at peak performance. We hope this information is a helpful resource for you. For tips and troubleshooting guides, check out our article on dust collector maintenance.

    If you have specific questions about your application and filtration needs, call today at 888-221-0312 or email us at [email protected] One of our dust collection specialists can assist you with your dust control challenges. If you have an upcoming dust collection project and need assistance, read Dust Collector Purchasing Guide or contact one of our equipment specialists at the number above.

  5. Dust Collector Purchasing Guide

    Leave a Comment

    Download the free PDF version of this Dust Collector Purchasing Guide here.

    Our dust collector purchasing guide will help you identify the right dust collection system that will perform safely, efficiently, and reliably for many years to come. Identifying the right components and needs for your next dust collector can be an overwhelming process. Factors to consider include:

    5 Things to Consider When Purchasing a Dust Collector

    1. Dust Properties – Learn the dust properties you need to be aware of to help you find the right filter media and type of dust collector.
    2. Volume – Understand key variables for measuring volume or airflow requirements in your work environment in order to size your collector properly.
    3. Air-to-Cloth Ratio – Learn why air to cloth ratio is important and how to find the right air-to-cloth ratio for your operation.
    4. Dust Collector Styles – Learn about three most common dust collectors, their advantages and disadvantages.
    5. Low Maintenance Design Features – Learn important dust collector design features that will help you save time and money in long term maintenance expenses.

    At the end of this dust collector purchasing guide, there are also additional resources that provide more details about combustible dust considerations and on demand cleaning.

    Dust Collector Dust Properties

    Dust Properties and Your Work Environment

    Do you know your dust? Consider your dust properties and characteristics of your work environment carefully to identify the best dust collection solution.

    Dust Properties to Consider:

    • Size – What is the size of the dust particles being filtered; fine or large?
    • Density – Is the dust low in density like wood dust or heavy in density like fine steel dust?
    • Chemistry – Will you be filtering any abrasive dust? Corrosive dust?
    • Temperature – Are you operating in a high heat environment? What is the operating or maximum temperature at your facility?
    • Moisture – Is moisture or oil present in the dust?

    Knowing your dust properties is the first step to help you determine the type of dust collector that is best suited for your unique application.

    Your Work Environment

    The next step to finding the right dust collection solution is to consider your space constraints, emissions requirements and temperature of your airstream.

    Space Constraints

    Dust collectors vary in height, width and depth depending on the application and the amount of dust being captured. Take note of any height or space restrictions in the work environment and take measurements of the space allotted for your collector along with the space available around the collector. Many dust collectors are top load which means you will need to allow space above the collector to replace and service the collector from the top of the unit.

    Emissions Requirements

    Depending on your application, your dust collector may require a permit with specific emissions requirements. These emissions requirements vary by state and are expressed as an efficiency percentage for cartridge collectors or an emission limit (e.g. lbs/hr or gr/dscf) for baghouses.

    Temperature of the Environment

    The temperature of the airstream will determine what type of filter media is required and will affect fan size. Temperatures greater than 260 degrees will require special filter media and changes to the dust collector fan. If the unit will be outside in a cold/extreme climate you will need to consider insulating the unit as well.

    Dust Collector Volume

    Understanding Volume or Airflow Requirements

    Calculating Your Airflow

    After considering your dust properties, the next step in dust collector purchasing is our airflow or volume requirements. Calculating your airflow correctly is critical to the long term health of your collector so your system will be efficient at capturing dust.

    Why is Volume Important?

    If the volume of the system is too low, your system will not capture the dust effectively which can impact production and air quality. If the volume of your system is too high, your energy consumption costs will be higher and you may disrupt the process of your application.

    How is Volume (Cubic Feet Per Minute) Measured?

    Dust collector volume is measured in cubic feet per minute or CFM. CFM is a measurement of airflow especially related to air conditioning, heating and ventilation environments like those requiring dust collection. In dust collector applications CFM measures the amount of air per minute that can be moved from a space.

    Variables to Consider

    Work environments vary dramatically from one another based on several variables, and even very similar environments can require vastly different volume. To determine the right volume capabilities for your new dust collector, consider some of the following variables carefully.

    • How are you collecting dust?
    • What is the size of the duct being used to collect the dust?
    • Cubic feet of the work environment

    Dust Collector Air to Cloth Ratio

    Air-to-Cloth-Ratio

    Dust collector air-to-cloth ratio is a critical measure to ensure your air filtration system is performing efficiently.

    What is Air-to-Cloth Ratio?

    Air-to-cloth ratio, also known as air-to-media, is defined as a measurement of the amount of air passing through one square foot of filler media. Generally the lower your air-to-cloth ratio, the more effectively your system removes dust from the work environment. If you are operating at a higher air-to-cloth ratio, one of the common issues you may encounter is a decrease in suction. This is because a large amount of dust laden air is filtered by an insufficient amount of filter media. The dust cake on the bag builds up too quickly; resulting in a decrease in air flow through the filters and suction at pickup points.

    How to Select or Calculate Air-to-Cloth Ratio

    If you’re sizing a new cartridge collector system and know what type of dust will be filtered and the air volume needed to properly ventilate the area or pickup points. Our Air-to-Cloth Guide below is a good place to start. The guide gives you a general recommendation on the air-to-cloth ratio for several different applications. To find the dust collector suited to your dust and air volume requirements simply:

    1. Divide air volume of system by air-to-cloth ratio to get the total amount of filter area needed into the system.
    2. Divide the total filter area by the filter area per filter to determine how many filters are needed in the dust collector.
    3. Find the dust collector model that best fits your application by number of filters
      and type of dust collector.

    To calculate air-to-cloth ratio in your existing system, calculate the volume of air (CFM) and divide that number by the total filter area within your dust collector. For example, a sixteen filter cartridge collector pulling 7,000 CFM would have a 3.65:1 airto-cloth ratio (7000 CFM / 16 filters x 120 ft2 per filter). Or in the case of a baghouse, a hundred filter baghouse pulling 10,000 CFM would have a 6.37:1 air-to-cloth ratio (10,000 CFM / 100 filters x 15.70 ft2 per filter). Environments with a large ventilation area or more pick up points require a higher air volume (CFM) to provide adequate suction which means more filter media to keep a similar air-to-cloth ratio.

    Air to Media Chart

    Why is selecting the right Air-to-Cloth ratio important?

    • Extends filter life
    • Minimizes your operating costs
    • Meets air quality goals and requirements
    • Allows your dust collection system to perform at peak efficiency

    What are the negative effects of improper Air-to-Cloth ratio?

    • Poor venting which causes damage to equipment
    • High pressure drops in differential pressure
    • Impacts your air velocity
    • Excessive use of compressed air

    Dangers of an Undersized Dust Collector

    Choosing a collector that is too small can cost you in long term maintenance costs. Some of the biggest problems we see people run into with an inappropriately sized dust collector are:

    • Consistently clogged filters (reduced filter life)
    • Increased downtime
    • Higher maintenance and energy costs
    • Decreased efficiency
    • Increased compressed air consumption

    To avoid the dangers of an undersized dust collector consider both CFM and air-to-cloth ratio carefully when designing your new unit.

    Baghouse Styles

    Dust Collector Styles

    Baghouse Styles

    Baghouses are ideally suited for large volume applications with airflow exceeding 1,000 CFM or when high temperature applications are above 375 degrees. In these environments, a baghouse will handle and most efficiently filter your dust laden air. There are several types or styles of baghouses available. Once you understand your dust properties, volume, and air-to-cloth ratio, you can determine the right baghouse style for your facility. Here is a summary of the pros and cons of the three most common baghouse styles: pulse jet baghouse, reverse air, or shaker style.

    Pulse Jet Baghouse

    ProsCons
    Bags cleaned continuously while unit is in operationRequires compressed air
    Easy to maintain, low maintenance costNot ideal for high moisture applications (+20%)
    Flexible Sizing and ConfigurationRequires filter cages

    Reverse Air Baghouse

    ProsCons
    Low maintenanceNeeds to be cleaned often
    Gentle cleaning which allows for longer bag lifeResidual dust build up is hard to remove
    Units are typically compartmentalized into sections which allows them to be maintained without shutting down the entire baghouseFilter bags are expensive compared to Pulse Jet bags
    Bags are typically custom made and not available in stock for quick shipment

    Shaker Baghouse

    ProsCons
    Very simple to operateLimited filter media options
    Low initial investment costNot space efficient (takes up a large area)
    Filters cleaned via shaker mechanismNot suited for high dust loads
    Bags are typically custom made and not available in stock for quick shipment

    What’s the Right Type of Pulse Jet Dust Collector?

    The three most common pulse jet dust collection systems are baghouses, cartridge collectors, and bin vents. Below is an overview of each type of pulse jet system and common applications for each:

    Baghouses

    Baghouses are typically the largest of the three types of dust collectors. They are well suited for large volume and high temperature applications. Baghouses are perform well for applications with high dust loads of more one 55 gallon a drum per day. The most common applications that use baghouses include:

    • Wood
    • Mining
    • Asphalt
    • Foundries
    • Cement

    Cartridge Collector

    Cartridge Dust Collectors are compact and very modular in design. These are best suited for applications with the following characteristics:

    • Moderate or low dust (collecting less than one 55 gallon drum per day)
    • High efficiency filtration requirements
    • Space restraints or small footprint requirements
    • Possibility of future plant expansion

    The most common applications for cartridge collectors include:

    • Welding
    • Grinding
    • Laser/Plasma Cutting
    • Bulk Powder Processing

    Listed here is a baghouse and cartridge collector comparison chart to help you determine which option may be best suited for your application.

    Baghouse and Cartridge Collector Comparison Chart

    FeatureBaghouseCartridge Collector
    Airflow Range (in CFM)1,000+ CFM500+ CFM
    Dust Loading Per DayMore than 55 gallon drumLess than 55 gallon drum
    TemperatureUp to 500°FUp to 180° F
    Design Features20-30 feet tall Pulse jet cleaning Reverse airflow cleaning (part that removes larger particles)7-12 feet tall More compact for applications where space is limited Higher efficiencies
    Common ApplicationsWood · Metalworking · Mining · Foundries · Tile · Drywall · Fiberboard ManufacturingWelding · Plasma Cutting · Grinding · Bulk Powder Processing · Paint Booths
    Type of Filter MediaWoven or feltPleated, non-woven

    Bin Vent

    Bin vents are usually used in applications where you are moving product from one location to another. Like a cartridge collector, bin vents are also compact, and designed for easy change-outs. They are designed to efficiently vent silos and tanks while minimizing product loss. Bin vents are frequently used in the following applications:

    • Cement
    • Agriculture
    • Tank Loading
    • Conveyor Belt

    Dust Collection Design Features

    Low Maintenance Design Features

    To avoid the hassle of excessive and costly change-outs and maintenance consider important dust collector design features that will help you lower your long term maintenance and energy costs.

    Listed below are some of the easy maintenance design features your dust collector should include.

    Dust Collector Design Features for Easy Maintenance

    • On-demand cleaning for reliable performance and
      reduced wear and tear
    • Modular design with low profile options for easy
      expansion and access
    • Filter change-outs performed outside or clean air side of
      the collector
    • No special tools or equipment required to perform
      change-outs
    • Quick removal access filter covers
    • Change-outs performed in 30 minutes or less
    • Standard filter sizes to ensure product availability and competitive prices
    • Multiple filter options for a variety of applications

    Dust Collector Additional Resources

    Additional Resources for Dust Collector Purchasing

    How to Prevent a Dust Collector Explosion

    If you are dealing with combustible dust, you’ll need to implement a preventive maintenance plan, which will help you avoid a serious dust collector emergency.

    What is combustible dust?

    Combustible dust can be defined as any fine material that has the ability to catch fire and explode when it’s mixed with the proper concentration of air.

    When can combustible dust create an explosion?

    When the right conditions are in place, combustible dust can become hazardous and create an
    explosion. Dust can collect on multiple surfaces in a facility (e.g. ducts, crevices, dust collectors, equipment, etc.), and once this buildup of dust mixes with the right conditions, it only takes a small ignition source to create a significant explosion. There are even scenarios in which combustible dust can self-ignite. This usually results from static that builds up as the particulates rub against one another.

    Who does it affect?

    Combustible dust effects a wide variety of industries such agriculture, metalworking, mining, chemicals, plastics, pharmaceuticals, etc. Industries that are susceptible to combustible dust are regulated by OSHA standards and NFPA guidelines.

    How can I prevent a dust collector fire?

    Now that you know what conditions required for combustible dust, when it can happen, and who it effects, how do you limit or prevent a serious explosion from happening? Your best plan of action is going to include steps that are proactive instead of reactive. Here are the proactive steps you can take:

    • OSHA Standards: Ensure you are meeting OSHA’s set of standards regarding
      combustible dust. Industries that are susceptible to combustible dust are regulated
      by OSHA standards when you implement OSHA’s set of standards, you are
      creating a safe working environment, avoiding property and economic loss from an
      explosion, and avoiding regulatory fines.
    • NFPA Guidelines: Make sure you are meeting codes outlined by the NFPA
      (National Fire Protection Agency). The NFPA publishes a list of guidelines that will
      help you minimize injury or death from combustible dust. The following codes are
      related to the most combustible types of dust (e.g. sugar, wood, fine aluminum):

      • 664, Standard for the Prevention of Fires and Explosions in Wood Processing and
        Woodworking Facilities
      • 484, Standard for Combustible Metals
      • 61, Standard for the Prevention of Fires and Dust Explosions in Agricultural and
        Food Processing Facilities
    • Preventative Maintenance Plan: Properly maintain your facility and dust collector
      to help prevent a buildup of dust. Clean up any excess dust build up on your dust
      collector, other equipment, vents, and filters.
    • Explosion Vents: Installing an explosion vent on your dust collector is one strategy
      that can minimize damage to your equipment and harm to employees should an
      explosion happen. The purpose is to relieve pressure in the dust collector caused
      by an explosion. Once the activation pressure is exceeded the vent(s) open safely
      relieving pressure.
    • Explosion Latches: Latches operate under the same concept as explosion vents.
      Latches provide venting in the event of an internal explosion.

    Dust Collector Purchasing Summary

    Selecting and pricing out a dust collection system involves careful consideration of each of the variables outlined above. Proper attention to these items is critical to ensuring your dust collector performs efficiently for many years to come and creates a clean, safe work environment for plant operators. Each dust collection application is unique, and it is possible that applications with very similar product characteristics or volume requirements may require a system that is vastly different due to the number of variables to consider. To help you engineer and select the correct system for your facility, consult with a dust collection engineering and manufacturing company with extensive experience designing systems for diverse applications.

    If you have further questions unique to your application or would like to speak with an engineer, give us a call at 888-221-0312 or email [email protected]

    Dust Collector Sizing Quiz

    Would you like to get a price range and a recommended cartridge collector? Simply complete this dust collector sizing calculator  and you’ll immediately receive an email with your recommended unit along with a price range for the unit.  A dedicated account manager will also contact you within 24 hours to assist in finding the right solution.

    Cartridge Dust Collector Sizing Quiz

  6. Air Pollution Control & Managing Industrial Dust

    Leave a Comment

    Disclaimer: The contents of this industrial dust blog are intended to be general safety guidelines. All businesses will still need to refer to OSHA, NFPA, and local ordinances required for their business.

    Industrial Dust Guide

    Dust builds up in your home may simply be a nuisance you take care of while spring cleaning. But in the workplace, dust can become a serious hazard if not properly handled. To get a better understanding of the negative effects of dust in the workplace we will provide a brief overview what industrial dust is, how industrial dust is created , potential dangers you should plan for, and the benefits of a properly engineered dust collection system.

    Industrial Dust Guide

    What is Industrial Dust & How is it Created?

    Dust consists of small particles of dry matter that build-up on hard surfaces such as floors, tools, industrial equipment, ducts, etc. Industrial dust can generate more frequently than household dust. This is because it generates from the daily from the manufacturing or production process. For example, a small woodworking shop could generate dust from activities like sawing, grinding, or cutting. Industrial dust can even break out during processing. Another example, in an agricultural facility process dust can come from sugar, flour, grains, etc.

    Common Types of Industrial Dust

    • Wood – Activities like sanding, high speed cutting, low speed cutting, paning etc. can create dust which is both explosive and fire prone.
    • Food Particulate– Certain food particulate can be explosive, abrasive and fire prone. This can encompass a wide variety of particulate such as flour, grains (corn, rice), soybeans, and more.
    • Cement & Concrete – This dust is abrasive but considered to be less explosive and prone to fire.
    • Paper Products – Dust created from paper products can be both explosive and fire prone.
    • Paint Powder – Paint pigments can be highly explosive
    • Pharmaceuticals – Pharmaceutical dust like dry powder and coating are both explosive and fire prone.
    • Plastic, Chemicals, Stone, Minerals , Metal etc.

    Is Industrial Dust Dangerous?

    The build-up of combustible dust is serious hazard in the workplace. Airborne dust presents a safety hazard to employees. Many types of industrial dust may contain carcinogenic properties that would require removal to keep employees safe, healthy, and to comply with government regulations.
    Airborne dust may also be highly flammable, and safeguards must be implemented to prevent the risk of a dust explosion.

    Conditions for a Dust Explosion

    • Oxygen
    • Enclosed space
    • Ignition source
    • Combustible dust at the right concentration level

    When you are working in an industry that operates with combustible dust, explosions and fires are a constant threat. If you are taking the right steps to ensure a safe working environment you are more likely to avoid a fire or explosion that would cost you the safety of your employees, thousands of dollars in lost production, and regulatory fines. Combustible dust can present itself in a variety of applications. Below are just some of the types of industries that work with combustible dust.

    Common Examples of Combustible Industrial Dust

    • Agriculture (grain, flour, sugar, etc.)
    • Wood
    • Metals (aluminum, zinc bronze, etc.)
    • Rubber
    • Chemicals (coal, Sulphur, etc.)
    • Pharmaceuticals
    • Pesticides
    • Plastics

    There are no short cuts to minimizing dust hazards and ensuring the safety of your employees. But understanding if you are working with combustible dust is the first step in prevention.

    Regulation of Air Pollution Control

    Many industrial industries in the U.S. must comply with strict air pollution control standards. These standards are set by the Environmental Protection Agency (EPA), National Fire Protection Agency (NFPA), OSHA, or local governing entities like the AQMD in California.

    OSHA regulates industries that are susceptible to combustible dust. When implementing OSHA’s set of standards, you are creating a safe working environment, avoiding property and economic loss from an explosion, avoiding regulatory fines. To learn more about OSHA’s safety standards for combustible dust, visit their guide here.

    The NFPA (National Fire Protection Agency) is another agency that publishes a list of guidelines to help minimize injury or death from combustible dust. The following codes are related to the most combustible types of dust (e.g., sugar, wood, fine aluminum):

    • 664, Standard for the Prevention of Fires and Explosions in Wood Processing and Woodworking Facilities
    • 484, Standard for Combustible Metals
    • 61, Standard for the Prevention of Fires and Dust Explosions in Agricultural and Food Processing Facilities

    How a Properly Engineered Dust Collection System Supports Air Pollution Control

    5 Benefits of a Dust Collection System

    Dust collection systems are engineered and designed to filter airborne industrial dust particles and debris that can cause damage to plant equipment, create a hazardous work environment, and negatively impact plant production. The top 5 benefits of a dust collection system are:

    1. Meet Compliance Regulations and Standards – All agencies require industrial facilities to maintain and meet air quality standards to ensure a safe and clean environment for their plant, employees, and the surrounding community.
    2. Boost Productivity – An accumulation of dust particles and debris on industrial equipment can interfere with overall plant performance. A dust collection system can collect these dust particles before they can interfere and compromise the health and performance of your manufacturing equipment.
    3. Improve Product Quality – Dust can settle and accumulate on products during the manufacturing process. This has a negative impact on the quality and consistency of finished goods. A dust collector will reduce and effectively capture these dust particles, allowing for product quality to improve and maintain consistency.
    4. Enhance Health and Safety Standards – Inhalation of hazardous dust affects human health and a dust collection system is vital to removing these hazards and to keep employees safe.
    5. Preserve the Quality of Equipment – As dust particles and debris are created inside a manufacturing facility, the contaminated dust will settle onto other surfaces such as computer systems and manufacturing equipment. This dust buildup can be harmful and result in malfunctioning equipment. It can also create unnecessary, frequent, and costly maintenance to keep dust and debris from accumulating. With a dust collector system purifying and collecting dust particles, the chances of excessive dust build-up is minimal.

    In addition to adding a dust collection system to your plant, you can also consider some of these dust removal options and explosion venting strategies.

    Baghouse Dust Removal Options

    • Enclosed Box – A simple pipe system funneling dust into an enclosed box, placed underneath your hopper, is one dust removal option.
    • Drum or Bag – A removable drum or bag can be a simple and easy solution to collecting and disposing dust.
    • Rotary Valve – Rotary valves (also known as airlocks, rotary feeders, or airlock feeders) help transition material from a dust collector to a drum or bin.
    • Screw Conveyor for Baghouse Dust Collectors – Large baghouses with heavy dust loads typically use screw conveyors. The screw conveyer would transport dust away from the collector, then send it to a designated disposal area.

    The best method of dust removal from your hopper is dependent on some of the following components:

    Explosion Venting Strategies

    Common Venting Strategies

    •Preventative Maintenance Plan: In conjunction with a protection strategy, every facility should implement a well-designed and operated preventative maintenance plan. Perform regular checks on the health of your dust collection system to prevent more serious issues.

    •Explosion Vent or Panels: Explosion vents or panels are designed to rupture at a set pressure (PStat). When a source of ignition meets a fuel source with sufficient oxygen present, an ignition will occur. As the ignition begins, the pressure inside of the vessel will increase rapidly. Depending on the material’s Kst value, the pressure rise may be slow or extremely rapid. As the ignition progresses, the internal pressure will meet the PStat rating of the explosion panel. The explosion panel will rupture, venting the ignition gasses. The explosion vent provides a relief avenue for the expanding gasses, but the pressure in the vessel will continue to rise until it reaches the Pred pressure. This is the maximum pressure of the ignition event when explosion vents are functioning, so this is usually the pressure rating the vessel is designed to withstand.

    You can use explosion panels with a short length of ducting to allow for interior use without flameless venting. They do require replacement once a rupture occurs, but they are simple, cost-efficient, and easy to install. Explosion vents are typically useful on baghouses and cartridge dust collectors.

    • Explosion Latch: Explosion latches work under the same principle as the explosion panels, but they are not single use. This is a more cost-effective option (versus explosion panels) when you have  a large baghouse or large quantity of vent area.

    Additional Venting Strategies

    • Flameless Venting: Flameless venting can consist of a flame arrestor element, vent panel, and flanged housing. This combines the techniques of explosion venting and flame arresting. You can also install a flame arrestor element over a standard explosion vent. When the vent ruptures, the burnt dust and flames enter the flame arrestor element. The element helps to contain the hazardous dust and flames and prevents it from exiting, where it could potentially ignite a secondary explosion or endanger employees. While flameless venting does stop flames from exiting the vessel, there will be extremely hot gasses exiting the flameless vent. When using flameless venting, make sure to pay close attention to the vents proximity to personnel areas. If possible, always aim flameless vents away from regularly occupied areas.

    • No Return Valve: Protecting the dust collector from over-pressure is essential, but it is equally important to stop a deflagration propagation back to the operator space. To prevent this, a No Return Valve is needed in the inlet duct. This valve is a weighted damper that is held open by the air flow during normal operation, allowing air and dust to pass through to the dust collector. In the event that deflagration occurs in the dust collector, the pressure propagation through the duct work will close the No Return Valve. This prevents the deflagration from reaching any process equipment and also limits the risk of secondary explosions.

    • Abort Gate: Abort gates are high speed dampers that contain a spring assisted blade and is typically held in place by an electromagnet. Their purpose is to minimize the risk of an explosion by diverting flame, spark, or debris from entering a facility through a return air system.

    • Spark Detection & Extinguishing System: This method uses infrared sensors, typically located on the ductwork, to detect sparks or burning material in the ductwork upstream.

    Secondary Event Protection

    All the methods described previously are excellent options for managing primary explosions, but one of the most catastrophic outcomes of a combustible dust explosion is an un-controlled secondary explosion.

    When a primary explosion happens, there may be a pressure wave that propagates through the plant. This will “kick up” the layer of ambient dust. If the explosion is not contained in the dust collection system using the methods previously outlined, this ambient dust in the air could come in contact with the primary explosion flame front. This results in an uncontrolled explosion in an occupied space.

    To minimize the risk of secondary explosions, the first step should always be to expect perfect performance from your dust collection system. It is not acceptable to have a dust collection system that does not function properly. Another suggestion is to limit the amount of horizontal surfaces in your plant that cannot be regularly cleaned. Drop ceilings and in-accessible equipment are great examples of this.

    There are many strategies that may fit your unique application or facility. We recommend to consult your local or state building codes and regulations before choosing your explosion venting strategy. Some areas will have specific regulations for fire safety and environmental safety, and you want to ensure you are meeting those guidelines. Here are some questions to consider before implementing an explosion venting strategy.

    Questions to Consider

    At U.S. Air Filtration, we have been eliminating the hazards of industrial dust for 35 years.
    To learn more about how you can manage industrial dust at your facility contact us at 888-221-0312 or [email protected] to speak with an engineer

  7. How Much Does a Dust Collector Cost?

    4 Comments

    Summary: Small dust collectors for applications up to 1,000 CFM airflow cost between $100 up to $5,000 USD.  Pre-fab dust collection systems such as a bin vent or cartridge type collector cost between $10,000 and $80,000 USD. Pre-fab units accommodate airflow volumes between 2,000 and 10,000 CFM. Custom baghouse dust collectors or multiple module bin vents and cartridge collectors range between $50,000 to $1 million USD and more.

    Watch Video: How Much Does a Dust Collector Cost?

     How Much Does a Dust Collector Cost


    Table of Contents

    • What is a dust collector?
    • Dust Collector Cost
    • What Goes into the Price of Your Dust Collector
    • Dust Collector Filter Media
    • Electrical Controls or Accessories
    • Summary
    • Dust Collection Resources

    What is a Dust Collector?

    Dry dust collection systems remove airborne dust that generate during manufacturing or industrial processing.  Examples include woodworking, bulk powder processing, or food production.  Dust collectors range from small portable units to extensive custom turnkey systems.

    wen-dust-collectors-air-filtration-3403-64_1000

     

    Dust Collector Cost

    Small Dust Collector Cost

    A small dust collector that is able to handle up to 750 or 1,000 cubic feet per minute (CFM) of airflow can cost between $100 up to $5,000.  These small retail units are ideal for ventilating two to three pieces of equipment (i.e. saw, sander, planer) for a small woodworking or metalworking shop.  Small units must be set up extremely close to the collection point. This reduces static pressure and fan size.  You can find these units at an online retailer or home improvement store.

    Large Dust Collector Cost

    Larger dust collection systems are needed to ventilate large scale processing equipment. These industrial dust collectors are found in some of the following commercial applications:

    • School woodshops
    • Metalworking facilities
    • Sandblasting
    • Chemical processing
    • Food processing
    • Cement production
    • Energy production
    • Mining
    • Foundries, and many others.

    Large dust collectors are designed to handle a much larger dust loads, meet higher airflow, or specific temperature requirements.  Pre-fabricated dust collection systems like a bin vent or cartridge dust collector can handle airflow volumes between 2,000 and 10,000 cubic feet per minute (CFM).  Depending on the size of the unit, filter media, and the fan size, units can range between $10,000 – $80,000 USD.

    Custom Dust Collector Cost

    Custom turnkey, dust collection systems that require complete engineering can range between $50,000 – $1 million USD or more. These systems can include one more pulse jet baghouses, multiple modular bin vents, or several cartridge collectors.

    What Goes into the Price of your Dust Collector

    The price of your dust collection system is also determined by several variables outlined below.

    Dust LoadUSAF CleanFlo Collector

    Dust load is the amount or volume of dust in your work environment that must be cleared within a given time period.

     

    Applications with higher dust loads require more filter media to remove airborne dust particulate.  This means you’ll need a dust collector with a larger footprint. This can drive up the overall cost of your dust collection system.  Applications that generate less than one or two 55 gallon drums of dust per day are usually good candidates for a small cartridge collector or bin vent.

    Type of Dust

    The properties of your dust particulate play an important role in the following:

    • Size of your system
    • Number of filters
    • Type of filter media
    • Filter treatments your application will need.
    • Air to Cloth Ratio
    • Fan Size
    • Temperature
    • Material Handling and Conveying

    To understand the characteristics of your dust particulate, you can ask yourself the following questions.

    Product

    What is being filtered?  Does your product contain moisture or oil?  Products with moisture content greater than 25% are not suited for a dry dust collection system. Products containing hydrocarbons, including oils, may require the application of a special treatment to get optimal filtration.

    Chemistry

    Does your airstream or dust contain chemicals that could damage filter media?  Are there also acids or alkaline in the airstream?  When certain compounds are combined during processing, a chemical reaction can occur. This may require additional media treatment or coating to protect the filter bags from accelerated wear.

    Abrasion

    How abrasive is the dust that’s being filtered?  Consider the hardness of the material along with the shape of the dust.  The velocity of your airflow can also make your dust more abrasive.  Highly abrasive dust may require your housing be fabricated in stainless steel, titanium or other costly materials that are able to withstand long term wear.

    Particle Size

    What is the size of the dust particulate are you collecting? Depending on your emissions requirements, your application may require a special membrane. This would apply if your particulate is very fine.

    Is your dust combustible?

    Combustible dust can be defined as any fine material that has the ability to catch fire and explode when mixed with the proper concentration of air.  Examples of combustible dust include:

    • Wood
    • Food products such as grain, sugar, flour, starch, metals
    • Rubber
    • Chemicals
    • Pesticides
    • Plastics, and more.

    OSHA and NFPA have created guidelines to protect your plant and employees from the risks of a serious explosion.  Also, be sure to review your state and local regulations for proper identification and management of combustible dust.

    Applications filtering combustible dust will also need an explosion venting strategy. Explosion vents or Brixton latches are two common strategies that help reduce this risk. You may also need explosion isolation valves in the dust collection line. This helps prevent a deflagration from travelling back to the equipment should an event occurs inside the dust collector.

    Dust Collector Filter Media

    The type of filter media you choose impacts your system startup and long term maintenance costs. Polyester filter media is an ideal for applications with temperatures below 250°.  Polyester is affordable, highly efficient and readily available.

     

    Other common filter medias include Aramid (Nomex©), Fiberglass, PPS, P84 and Teflon.  You can add treatments to  filter media to enhance it’s efficiency and performance. Treatment for your filter is dependent on your dust characteristics.  In addition, treatments can drive up the cost of your filter bags but also extend it’s life, reduce changeout’s and drive down long term maintenance costs.

    Cartridge Dust Collector

    Air to Cloth Ratio

    Air to cloth ratio, also known as air to media ratio, is a measurement of the amount of cubic feet per minute of air passing through one square foot of filter media.

     

    You can calculate air to cloth ratio based on the size and type of dust particulate you are filtering. It’s an important element in the design and size of your dust collection system.

     

    Generally, the lower your air to cloth ratio, the better your system is at removing dust from the work environment.  However, if your air to cloth ratio is too low it can place unnecessary strain on your dust collector.  Systems that operate at a higher air to cloth ratio have a smaller footprint, size, and price than dust collectors operating at a lower air to cloth ratio.

    Fan Size

    Your dust load, CFM requirements, and static pressure measurements will determine the size of the fan that will pull dust through the system and turn the air.  Your dust collector’s location is relative to the work environment being ventilated and also impacts the size of your fan.  Systems installed close to the work environment can reduce the length of ducting and static pressure. As a result, a smaller fan may be required. The cost of a fan can vary depending on each of these factors.

    Temperature

    Applications operating above 250 degrees Fahrenheit may require more expensive filter media. These applications would need their filter to withstand long term exposure to high temperatures.

    Material Handling & Conveying

    Once your dust particulate has moved through your dust collection system and lands in the hopper, you’ll need to determine how to properly remove the dust. This ensures it doesn’t return into the airstream and plug up your system.  Drums are the most economical option. They perform well when handling waste material with light inlet dust loading.  Light inlet dust loading applies if you generate, at most, a one or two 55 gallon drum of dust per day.

     

    Applications with higher dust loading requirements or those filtering non waste product, need an advanced system to convey material. This helps prevent the drum from overfilling, which can cause dust to back up or return into the hopper.  This can also result in a processing issue that will impact your dust collector’s performance.  In these situations you may need to upgrade from a drum to a larger dumpster, rotary or dump valve.

    Rotary Valves

    Rotary valves seal the bottom of your collector. They help prevent outside air from entering the system while allowing material to be continuously emptied from the hopper.  The cost to add a rotary valve to your dust collection system can vary between $3,000 and $5,000 USD.  

    Pneumatic Conveying

    Larger applications may also require a vacuum pneumatic conveying system. Their purpose is to vacuum material from the dust collector discharge to a common point.  For example, an application with five baghouses may include a common vacuum conveying system. It would help pull discharge material from all five baghouses to one common dust collector discharge area.

    Paints, Coatings 

    Applications with high moisture levels or chemical resistance may require an upgrade to epoxy paint. It can be applied to the interior and exterior of the dust collector. This helps to reduce long term wear of the system. Facilities located near an ocean, lake, or those that process caustic chemicals would use epoxy paint.

    Unit Insulation

    Insulation may also be required if you’re airstream temperature is high and must remain above the dew point in gas form. This eliminates the risk of moisture and condensation. Airflows with high moisture content can cause performance issues with your filter bags. This can include plugging of the system and inefficient filtration. Applications requiring insulation include ventilation of exhaust air coming off boilers, burners during metal forming, and similar processes.

    Electric Controls or Accessories

    Most baghouses, cartridge collectors, and bin vents come standard with an electrical control panel. This powers your pulse cleaning system and your fan separately.  Most experts recommend to integrate your control panel into a starter panel. This powers your pulse cleaning and fan at the same time.

     

    Installation of starter panels can be done at any desired location in your plant regardless of the distance to the dust collection system. Starter panels protect your system from surges or motor damage.  While the addition of a starter panel can add to the initial cost of your system, the ease and added safety it offers make up for startup costs.

    Dust Collection Design Considerations 3

    Is an OEM Dust Collector like Torit Right For Me?

    We recently took a survey asking customers their attitude and preference towards OEM vs. aftermarket dust collection products. Here’s what we learned:

    • 15% of buyers prefer OEM dust collector parts and equipment exclusively
    • 85% of buyers like the option to purchase OEM or aftermarket dust collector parts and equipment
    • 65% of buyers who purchase aftermarket said they get the same performance as an OEM at a more affordable price and/or don’t care about having brand name components.
    • Another 50% prefer aftermarket products because they are more affordable
    • Of the 15% of buyers who only purchase OEM,  the most popular reason for choosing OEM is because they believe they can be trusted to perform long term (33%).

    If budget is not a factor for you and you are willing to pay more for OEM then this may be the right solution for you.  However if you are looking to get the same long term performance from a dust collection system as an OEM and don’t want to pay a higher price for a brand name, then a U.S. Air Filtration system may be a fit.

    Summary of Dust Collector Cost

    Selecting and pricing out a dust collection system involves consideration of each variable above.  Understanding each of these variables is critical to ensuring your dust collector performs efficiently for many years to come while also creating a clean and safe work environment. Each dust collection application is unique so it is possible that applications with very similar product characteristics or volume may require a system that is different in price and size.

     

    To ensure a successful solution, consult with a dust collection engineering and manufacturing company with extensive design and manufacturing experience.  An experienced dust collection engineering firm can help you engineer a system customized to your unique application requirements.

     

    If you have any questions unique to your application, give us a call at 888-221-0312. You can also email [email protected]. In addition, below are some related videos and resources that may help.

    Dust Collection Resources

  8. Baghouse Dust Removal Options

    Leave a Comment

    Why Baghouse Dust Removal Matters

    The right baghouse dust removal method can help minimize problems that arise due to dust build up in your hopper.

    A hopper is designed to be temporary storage for your discharge. What happens if you have excessive dust build up in your hopper? This can result in your air flow being blocked off and would cause a loss of suction throughout the dust collection system.  This can also become a hazard because it’s more opportunity for combustible dusts to create a dangerous explosion. The right dust removal method for your application can help you avoid these issues.

    Key Components

    The best method of dust removal from your hopper is dependent on some of the following components:

    • What’s your Dust Collector Type? Baghouse or Cartridge Dust Collector?
    • What are the characteristics of your dust? For example, hazardous or non-hazardous?
    • What are the loading rates of your dust?

    Baghouse Dust Removal Methods

    Baghouse Dust Collector

    Enclosed Box

    A simple pipe system funneling dust into an enclosed box, placed underneath your hopper, is one dust removal option. Your maintenance team would be required to monitor and empty the box once capacity has been reached. Prompt removal of dust build up in your enclosed box helps prevent backup or an overflow of the box itself. Non hazardous dust and light dust loads typically use enclosed boxes.

     

    Drum or Bag

    A removable drum or bag can be a simple and easy solution to collecting and disposing dust. Once a drum or bag fills up, maintenance simply removes it by hand or forklift. Once empty, the drum or bag can then be put back into its place. This is ideal for non toxic dusts that you can easily handle.

    Rotary Valves for Baghouses

    Rotary Valve

    Rotary valves (also known as airlocks, rotary feeders, or airlock feeders) help transition material from a dust collector to a drum or bin. It seals a pressurized system against loss of air and pressure. This minimizes product loss during processing. Dust collection, pneumatic conveying, mixing, weighing, feeding, and blending use rotary valves. Larger baghouse systems with over 10,000 CFM  can also use rotary valves.

    Screw Conveyor for Baghouse Dust Collectors

    Large baghouses with heavy dust loads typically use screw conveyors. The screw conveyer would transport dust away from the collector, then send it to a designated disposal area. This is ideal for hazardous or reused materials.  Agriculture, mining, foundries, wood production, and chemicals are applications that use screw conveyors.

    Would you like to learn more about design considerations for a new dust collection system? For more information, download our dust collector purchasing guide.

    Dust Collection Design Considerations 7

  9. Different Baghouse Styles: Advantages and Disadvantages

    Leave a Comment

    When it comes down to finding the right dust collection system, there are a few different baghouse styles to choose from. So how do you know which one is best for you?

    Baghouse Styles

    Before we dig into the differences between some of the baghouse styles, you need to consider your dust properties and air-to-cloth ratio.  Baghouses are ideally suited for large volume applications with airflow exceeding 1,000 CFM or when high temperature applications are above 375 degrees.  In these environments, a baghouse will handle and most efficiently filter your dust laden air. 

    There are three main baghouses styles (e.g. shaker, reverse, and pulse-jet)  that are commonly used in most industrial processing and manufacturing applications.  Here’s a brief overview on the pros and cons of each to help guide you in identifying the right option for your work environment.

    Pulse Jet Baghouse 

    Pros:    Cons:
    Constantly cleaned so there is minimal dust build up in the dust collector   Requires dry compressed air
    Space Efficient   Cannot be used when there is humidity of high moisture content present
    Requires fewer bags   Cannot handle high temperatures (unless you use special filter media
         

    Reverse Air Baghouse 

    Pros:  Cons:
    Can handle high temperatures Needs to be cleaned often
    Gentle cleaning which allows for longer bag life Residual dust build up is hard to remove
    Units are typically compartmentalized into sections which allows them to be cleaned without shutting off the entire baghouse Low air-to-cloth ratio
       

    Shaker Baghouse 

    Pros:     Cons:
    Very simple to operate     Cannot handle high temperatures
    Low initial investment cost     Not space efficient (takes up a large area)
    Units are typically compartmentalized into sections which allows them to be cleaned without shutting off the entire baghouse     Energy and time sensitive 
  10. What Volume Dust Collector do I need?

    Leave a Comment

    Do you have a new dust collector project in the works and need help determining the volume? Our introduction to dust collector volume can help with that.

    Baghouse Dust Collector

    The Right Volume

    The most important consideration to factor into a new dust collector is making sure the airflow or volume of the dust collector is efficient at capturing dust and is right for your application.

    For instance, if the volume of your system is too low then your system will not filter dust as efficiently. As a result, your production, air quality and life of your collector can be shortened.  Similarly, if it is too high then your energy consumption costs can be higher and you could disrupt the process of your application. 

    Measurement of Volume

    You measure volume in cubic feet per minute or otherwise known as CFM.  CFM is a measurement of airflow related to air conditioning, heating and ventilation environments. In dust collector applications CFM measures the amount of air per minute that can be moved from a space.  

    Work environments vary dramatically from one another based on several variables. Even very similar environments can require vastly different volumes. To determine the right capabilities for a new dust collector, here are some variables to consider carefully.

    1. How are you collecting your dust?
    2. What is the size of your duct being used to collect the dust?
    3. What is the cubic feet of your work environment?
    4. Calculating volume for new installations.

    Do you need more detailed information? Download our full guide to dust collector volume below. In addition, it comes with a chart that can be helpful for your new dust collector project.

     A Guide to Dust Collector Volume

    Do you have more questions or need some help? Our equipment specialists are also available at 888-221-0312.

    Related Resources:

    Video: Air to Cloth Ratio

    Video: How Much Does a Dust Collector Cost?

    How to Get the Right Dust Collector for your Application