Dust Collection Can Velocity
- 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.
- Volume – Understand key variables for measuring volume or airflow requirements in your work environment in order to size your collector properly.
- 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.
- Dust Collector Styles – Learn about three most common dust collectors, their advantages and disadvantages.
- Low Maintenance Design Features – Learn important dust collector design features that will help you save time and money in long term maintenance expenses.
When sizing a new dust collector, these factors, along with understanding the importance of can velocity, will allow you to avoid unnecessary difficulties that would prevent your system from performing at peak efficiency.
What is Can Velocity in a Dust Collection System?
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. The right can velocity for your dust collection system will be based upon your application and the density of your product. At US Air Filtration our engineers calculate your can velocity based on a few different factors.
The different dust characteristics and operating factors that help us understand can velocity are:
- Particle size
- Bulk Density
- Agglomerating/non-agglomerating (stickiness of the material)
- Loading rates
How to Calculate Can Velocity for a Dust Collector
In simple terms, the calculation is based on the area of the bottom of your dust collector’s filter bags. For example, if you have a dust collection system with 200 filter bags the calculation is the following:
Graphic Above: Dust collector housing ➖ area of the round bottom of the bags (qty 200) ➗ divided by volume
Impacts of Improper Can Velocity in a Dust Collection System
Low Can Velocity
- Low can velocity can lower air speed. If left for an extended period of time, dust can begin to accumulate inside your duct work. This build-up of dust work can cause a decrease in airflow or suction at your pick-up points, thereby resulting in an insufficient performing dust collection system.
High Can Velocity
- High can velocity can cause higher differential pressure and an increase in cleaning cycles of the pulse-jet cleaning system. This can result in filter bag abrasion caused by too much airflow through the dust collector housing and increased energy costs.
- A dust collection system with a high can velocity may filter as you expect at first, but as time goes on, dust will continue to cover the filter bags. The dust collection system will not be able to drop the dust off the bag, therefore the permeability per bag will decrease, and you will lose airflow.
How To Solve High Can Velocity
Solving for an excessively high can velocity can be tricky. We recommend working with a U.S. Air Filtration engineer to help determine what the right solution would be for your particular problem and dust collection needs. In general, some of the solutions can include:
- Increasing the size of your dust collector
- Reducing the airflow.
- Lowering your volume
- Possibly a baghouse conversion, but in certain cases this may only lower your air to cloth and not remedy a high can velocity
- Inlet placement
Industrial dust collection suppliers generally quote systems based on air to cloth ratios, but it’s important to keep in mind that air to cloth ratio and can velocity are related. Can velocity is a variable to consider depending on what type of material you have. For example, if your application includes very light material, we recommend paying close attention to the quotes you’re receiving. If one potential supplier has quoted you with a low inlet, high can velocity, and a price that is significantly less, then that dust collection system will have higher differential pressure, an increase in cleaning cycles, too much airflow through the dust collector housing causing filter abrasion, and ultimately be unable to perform as it was intended to.
Considering all the components involved in choosing the right dust collection system can be an overwhelming process. While it’s important to understand the impact of can velocity on both performance and price, our ultimate goal at U.S. Air FIltration is to provide you with the full service of designing and engineering the right dust collection system that will meet your specific needs and requirements. When you work with U.S. Air Filtration engineers for your next dust collection project, they will ensure you have the right air to cloth ratio and can velocity that will allow your system to perform safely, efficiently, and reliably for many years to come.
If you’re just getting started, you can request a free project consultation with a dust collector equipment engineer here. Get assistance with can velocity, CFM, volume, filter media, design spec recommendations, and more.
Costs of Baghouse Ownership
Industrial dust collection systems are vital to maintaining efficient plant production and ideal working conditions. Dust collection systems designed to filter airborne dust and debris can range from small bin vents to complex and customized turnkey baghouse systems. There are several factors that play a role when choosing the right dust collection system for your facility. These factors, along with assessing up-front and long term costs of baghouse ownership will help guide you to the dust collector that can handle your filtration needs, while offering long-term cost-saving features.
In a new dust collection project you have two types of costs; up-front and long-term. Up-front costs play a major role, but equally important are long-term operational costs which can add up significantly over time.
Upfront Costs of Baghouse Ownership
- Cost of engineering and design
- Shipping costs
- Baghouse system and parts
Long Term Costs of Baghouse Ownership
Stack testing: The frequency and requirements for stack testing will be determined by your state or local air pollution office. For example, if you are located in California you would refer to the AQMD office for the rules and regulations your facility needs to meet.
Energy Usage: This includes the energy costs to run the dust collector itself and all of its components. The dust collector component to consume the largest amount of power from a baghouse would be the fan, and fans can consume up 95% of the baghouse energy. Other costs include the compressed air being used to clean filters.
Cost Saving Tip: On-Demand cleaning improves dust collector performance while reducing energy consumption and labor costs. Learn more about on-demand cleaning for Pulse-Jet technology in this article here.
Replacement Parts: The 5 most commonly replaced parts on a dust collector are filters, pulse valves, timer boards, solenoids, and diaphragm kits. Beyond the replacement parts on the dust collector itself, you will also want to consider the replacement costs for the dust collector’s accessories. This may include:
- Fan: With proper maintenance of the fan’s belts and bearing, a fan can typically last as long as the baghouse itself. For free access to a fan maintenance guide, head over to our PDF here.
- Screw Conveyors: Being on the dirty side of a dust collection system, a screw conveyor receives a lot of wear and tear. This is the reason why a screw conveyor may wear out before the lifespan of a baghouse ends.
- Duct Work: Abrasive atmosphere or dust can contribute to the erosion of ductwork.
Cost Saving Tip: Understanding the signs of a worn out dust collector part can help you identify any issues before they become larger problems. Learn more about the common warning signs in our video here.
Shipping: These are costs associated with shipping replacement parts.
Cost Saving Tip: Eliminate price increases and delayed lead times with automatic parts delivery that you have full control over. Get answers to the most frequently asked questions about parts delivery here.
On-Going Maintenance: One of the tips to maximizing the life of a dust collection system is implementing a preventative maintenance plan. Depending on your system, preventative maintenance checks can be weekly, monthly, semi-annual and annual. For access to a comprehensive dust collector maintenance guide with free PDF download, visit our article here.
Beyond preventative maintenance, there is a 22-point inspection which can ensure your system is running at its peak performance. To get more information on a 22-point inspection and what it includes, check out this article here.
Waste Disposal: Costs associated with removing and disposing of dust and debris.
Labor for Change-Out’s: There are multiple factors that drive the cost of labor for a change-out. Some of these include travel, number of filters being replaced, the environment of the dust collector, and more. When you choose to outsource this service to experts, it may include:
- Changing filters
- Seal minor air leaks
- Repair or replace damaged solenoids, valves, or diaphragm kits
- Any other repairs or troubleshooting needed on a baghouse – for example, vibration issues with a system after a filter change
If you are looking for more information on dust collection services and the commonly asked questions needed to determine cost, get full insight with this guide.
Highest Long Term Costs of Baghouse Ownership
Replacing dust collector parts like the filter cartridges, filter bags, the delivery cost for those replacement parts, the labor costs to switch out or maintain those parts, and maintaining inventory will be some of the highest long-term costs you incur. Filter replacements will be your highest maintenance item moving forward because, depending on your application, the lifespan of a filter can be anywhere from 1 year to 5 years.
Lifespan of a Baghouse
A properly maintenanced dust collection system in a non-abrasive environment can typically last around 20 years. On the other hand, the lifespan of a dust collection system in an abrasive environment is only between 5-10 years. An example of an abrasive environment can include a dust collector sitting outside of a plant, near the beach. In this scenario, you may start to see rust on the housing within 5 years.
How to Extend the Life of a Baghouse
We understand that getting the most out of your dust collection system is important. Below we are sharing our top tips that can help extend the life of your baghouse.
- Eliminate or reduce the unscheduled shutdowns by maintaining inventory levels.
- Your compressed air source should be dry and oil free, otherwise it can interfere with your pulse bounce
- Use the right air-to-cloth ratio
Benefits that Extend the Life of a U.S. Air Filtration Dust Collection System
To help further maximize the lifespan of a dust collection system U.S. Air Filtration offers the following benefits.
- U.S. Air Filtration primes the inside walls of your dust collection system to add a layer of protection
- Additional epoxy paint options can be added if required (additional cost varies depending on system size, paint, etc.). For example, a cement barge loading or transferring cement that may require a marine grade epoxy on their dust collection system.
- U.S. Air Filtration fabricates our dust collection systems in 10 or 12 gauge, while other suppliers may provide a thinner 14 gauge to cut costs
- Where applicable, heavier duty equipment may be provided as an option to lengthen the accessory’s lifespan. For example, a 5HP drive for a 20 foot screw conveyor instead of the typical 2 HP.
Dust Collection Cost-Cutting Steps to Avoid
If purchasing decisions are made solely based on the cost of equipment and not quality or application, you could end up spending less up front, but increasingly more over time. Some of the shortcuts to avoid on the front end are:
- Improper Air-to Cloth Ratio: Air-to-cloth ratios may cut up-front costs but they also cut you short on static pressure. For example, baghouses with a 10:1 air-to-cloth ratio will give you inconsistent suction at your pick-up points, resulting in clogged filters and more frequent change outs. Ultimately you’re going to be paying more in the long run than you would have if a proper air-to-cloth ratio was considered. To get a better understanding of the importance of air-to cloth-ratio or how to calculate it, access our latest video here.
- Cheap Baghouse Material: Avoid suppliers that fabricate their systems with the bare minimum materials and construction.
At U.S. Air Filtration we do not have a cookie cutter approach. Every dust collection project is specific to the customer. Therefore, we recommend working with an engineer to customize a dust collection system that will meet the unique characteristics and needs of your facility. This is the best approach to getting the long-term performance you need out of a dust collector.
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:
- How cyclones work
- The benefits and disadvantages of a standalone cyclone
- Common applications, and the advantages of a combination cyclone and baghouse or cartridge dust collection system.
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.
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.
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
- Paper Products
- Rubber Plants
- Food Manufacturing
- Bulk Powder
- Industrial Equipment and Machinery
- And More!
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.
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.
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
- Dust Properties
- Your Work Environment
- Space Constraints
- Emissions Requirements
- Temperature of the Environment
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.
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.
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
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.
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 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
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:
- 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.
- If there are no taps, how are people using the machine?
- Is the machine stationary?
- Does someone need access 360 degrees around the machine?
- 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
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
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
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]
When calculating the life expectancy of your filters, there are multiple environmental factors that come in to play. Filters can last anywhere from a few weeks up to 5 years or more, but it really varies. The top factors that can influence filter life are:
But what if your filter bags fail sooner than expected? Here are a few reasons they may be failing prematurely.
Standard dust collection systems are designed for dry dust environments. If you have over 20 percent of moisture or oils in your process (e.g., working with fertilizers or concrete) you may need to consider a different type of filtration system. If you continue to operate with uncontrolled moisture, the physical properties of your dust may change due to the increase in water content. Certain types of dust can then become sticky or heavy which would cause your dust cake to build quickly, affect the ability of dust to fall off during cleaning and thereby creating a scenario where your filter bags fail prematurely. An excess of moisture can also cause excessive dust build-up in your duct work, rotary valve, and inside the dust collector’s walls. Common industries that deal with moisture are:
Industries with Moisture
When considering how abrasive your dust can be, consider the hardness of the material being filtered along with the shape. If material is abrasive, a filter bag media with the ability to resist the additional wear and tear is generally recommended. Different types of filter media more resistant to abrasive dust are:
Filter Bag Media Used with Abrasive Dust
- Aramid (Nomex)
The velocity of your airflow can also make your dust more abrasive. Highly abrasive dust may require your housing to be fabricated in stainless steel, titanium or other costly materials that are able to withstand long term wear.
Filter Bag Fit & Installation
Filter Bag Fit
To help give your filter bags better life expectancy, make certain to have the proper bag to cage fit. Filter bags with the correct flex allows the precise amount of momentum to happen when the filters hit the cage. Filter bags with insufficient flex are too rigid and can prevent dust build-up from properly falling off during the cleaning process. The general recommendation is to have between 1/4″ to no more than 3/8″ pinch on your filter bag on each side of the cage. Filter bag media with sensitive bag to cage fit are:
Sensitive Bag to Cage Fit
If you have filter bags with the following medias, also consider oversizing your filters due shrinkage that can occur in temperatures above 450 Degrees F.
Sensitive to Shrinkage
Filter Bag Installation
Proper installation of filter bags allows for optimal dust handling and cleaning efficiency. When it comes to filter bag installation, common errors to watch out for are:
- Top Load –The groove between the double beaded snap band should be set into the cell plate. For a video tutorial on the proper way to install this type of filter bag, visit this guide here.
- Bottom Load – Raw top bags should be folded over the cage with enough material to allow for proper and tight clamp placement.
Undersized Dust Collector for CFM
A couple of the biggest problems we see people run into with an inappropriately sized dust collector are:
- Consistently clogged filters
- Reduced filter life
- Higher maintenance costs
To avoid the dangers of an undersized dust collector, consider both CFM and Air to Cloth Ratio. For example, if you have an air to cloth ratio that is too high, the dust you are trying to collect embeds into the filters too fast for your system to efficiently pulse. You end up with rapid build-up of dust, which ends up clogging your filters and making your dust collector work even harder than it should be.
Prevention is the best method for avoiding filter bags failing prematurely and total dust management. Achieving longer filter bag life means the design of your dust collection system should be correct for your specific application from the very beginning.
At U.S. Air Filtration our specialists are available to help with the design of your dust collection system. Or if your filter bags fail continuously, we can help guide you to the right solutions. For assistance now, contact us at 888-221-0312 or email [email protected].
Unfortunately, shipments from any dust collection supplier you work with can sustain damage during transit. While you cannot control what happens in-transit, you can control how you respond to freight that arrives damaged.
How Damaged Freight Affects Your Bottom Line
Shipping claims and getting replacements for damaged freight can be a frustrating to deal with, but the true price tag of this issue can cost far greater than just a few broken boxes or lost product. Other costs to your business may include:
- Unscheduled Shut Down
- Lost Production
- Reduced Product Quality
- Regulatory Fines for Non-Compliance
Minimizing Damaged Freight Issues
The U.S. Air Filtration logistics team understands that packaging can play a role in the potential of damaged freight. Your shipment will be handled by many people along the way. So we keep this in mind when we prepare your dust collection order for shipment in the U.S. Air Filtration warehouse, and we follow a system of best practices that can help protect your items as much as possible.
- Inspection –To avoid shortages we inspect, count, and match up the items to your packing slip.
- Right Packaging – Our team makes sure that the box is suitable for the item that is shipping.
- Proper Seals – We distribute tape evenly to ensure your product stays fully sealed in its package. For palletized items, we shrink wrap your freight multiple times to ensure all boxes remains together.
- Appropriately Sized Pallets – Our warehouse team makes certain that the right sized pallet, also known as a skid, is the right one for the weight and size of the shipment.
- Clear Shipping Labels – Labels are legible and durable. Paperwork such as a bill of lading or packing slips are placed inside of a protective sleeve.
How Do I Receive Freight?
There is one golden rule of receiving freight that every receiving dock should follow. Do not accept or sign the bill of lading before checking freight for damage, concealed damage, or missing parts.
It’s critical to pay close attention and inspect all details when you receive a freight shipment. You have the right to record exactly what is missing or damaged. If damaged freight is not recorded, you may not be able to file a successful freight claim.
When you receive freight, here are the steps you should take.
Box Count & Damage Inspection
- Count the number of boxes received. Compare the box count to the bill of lading for accuracy.
- Inspect the shipment for any visible damages. Ensure all packages are consistent.
Are there any damages present? If yes, then take immediate action with the following steps.
- Accept the shipment as damaged.
- Write down all damages or missing box count on the delivery slip.
- Take photos to showcase the condition of goods when received.
TIP: Do not refuse a shipment or discard any damaged freight. Your shipment may get damaged further, or worse, lost in storage. Without your dust collection products in-hand, getting replacements or a freight claim solved can take several weeks longer.
TIP: Keep a copy of all related documents like the bill of lading, packing slip, and copy of your invoice.
TIP: There is a limited window of time to submit a freight claim for resolution.
Report any damages to your supplier within 24 hours of receiving your shipment and they will help your take the next steps. If your shipment was from U.S. Air Filtration here is what you can do:
- Contact your account manager directly or the USAF main line at 1-888-221-0312.
- Send all photo evidence and a copy of the delivery slip to USAF.
- USAF will help start the freight claim process and get you replacements ASAP.
Damaged freight is a headache that no one wants to deal with. They strain your time and bottom line. If you would like to get help with your damaged shipment, submit your information with our interactive receiving checklist below. Once your information is received, a U.S. Air Filtration rep will be in touch to help.
Top 3 Low Temp Filter Bag Media
If your plant is operating from ambient to 275 degrees Fahrenheit, there are a few low temp filter media bag options you can choose to use in your dust collection system. To guide you to the right one, we’ve gathered information on the three commonly used medias in low temperature dust collection applications. The following filter medias are generally for dry dust applications with very little moisture and no issue heats or acids.
Polyester is one of the most economical low temp filter bag medias used in the dust collection industry because of its reliable performance in a broad range of applications and availability. This media is used in industries including food manufacturing, woodworking, metalworking, building products, and energy. Polyester is one option if you are continuously operating between ambient – 275 degrees Fahrenheit, and have less than 10% moisture.
Polyester Filter Bag Media
|Max Continuous Operating Temperature||275 Degrees F.|
|Low cost and widely available filter media.||Does not perform well with moist heat.|
Polypropylene is another relatively low-cost, low temp filter bag media. The big difference between polyester and polypropylene is that polypropylene can withstand some moisture. If your continuous operating temperatures are between ambient – 170 degrees Fahrenheit, and you have more than 10% moisture in your application, then Polypropylene could be the right fit for your baghouse.
Polypropylene Filter Bag Media
|Max Continuous Operating Temperature||170 Degrees F.|
Another option for applications with more than 10% moisture is Acrylic. This is similar to polypropylene but more expensive. Acrylic can handle moisture better than polyester and has a higher temperature rating. If you need to run between 200-265 degrees Fahrenheit, but you have moisture, you could use acrylic.
Acrylic Filter Bag Media
|Max Continuous Operating Temperature||265 Degrees F.|
Assistance with Low Temp Filter Bag Media
If you have a unique application we can help get some answers to your questions. Reach a dedicated account manager at 888-221-0312 or email [email protected]
Are you looking for high temperature media options? Then check out our guide here.
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.
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
- 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.)
- Metals (aluminum, zinc bronze, etc.)
- Chemicals (coal, Sulphur, etc.)
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
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:
- 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.
- 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.
- 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.
- 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.
- 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.
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:
- 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?
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
- What are the state and/or local regulations for fire safety and explosion venting that will protect my staff and facility?
- Is the dust collector setup inside or outside?
- What is the distance of the dust collector from the roof or walls?
- Is the dust collector or vent close to any other structures?
- What’s the cost?
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
How Shaker Filter Bags Collect Dust
Shaker baghouses collect dust similar to reverse air baghouses. Dust collects on the inside surface of the shaker filter bags, and then clean air exits through the top of the bag. The main difference is how the bags cleaned.
How to Clean Shaker Filter Bags
Shaker baghouses are engineered so that filters are hung and tensioned from the top of the unit, and at the bottom they are attached to a tube sheet. Mechanically shaking the filter bags is what cleans them. Shaker baghouses only clean while the system is off-line. Shaker baghouse operation is simple and can be seen in applications where no compressed air is available.
Construction of Shaker Filter Bags
Fabric filter bags used in shaker baghouses are typically constructed with woven or light weight media options like polyester sateen, shaker felt, beane knit, and more. Treatments are dependent on a plant’s application and dust characteristics. The most common top and bottom configurations for shaker baghouses are below.
Most Common Top & Bottom Construction for a Shaker Baghouse
Top Load Baghouse: Grommet Top, Loop Top, Strap Top
Bottom Load Baghouse: Corded Cuff Bottom, Double Beaded Snap Band
If you would like to get a free media recommendation, check out our filter bag media quiz here. There is also a fabric characteristics sheet that you can download below. It takes a closer look at the most common filter bag medias used in the dust collection industry.
Filter Bag Resources
To learn more about how to select the right filter bags, you can download our filter bag guide with the link below. The guide provides resources on key topics such as; dust properties, filter media, finishes and treatments, construction, and air-to-cloth ratio.
Looking to start with the basics? Watch this “Guide to Filter Media” video to learn more about the most common medias used in the industrial dust collection industry.
Are ready to get a set of filters? Check out our online product catalog below. You can also request a quote within 24 hours, call at 888-221-0132, or simply email [email protected]