In this design guide we have reviewed a relatively simple baghouse dust collection system with few variables. Even at this level it is still recommend to consult with an experienced dust collector OEM like Baghouse.com before making any equipment purchase. There may be additional factors to consider before determining the final sizing, design, construction and installation of a dust collection system.
Common Additional Considerations
- Recirculating air back into facility
- Balancing system with blast gates
- Combustible and toxic dust
- Filter styles
- Dust discharge (manual or automatic)
- Option for VRD fans
Recirculating Air Back Into The Facility
Recirculating air from the dust collector exhaust can prove practical in areas with cold climates to conserve heat. Make sure to include a ambient air return line to balance the airflows and prevent carbon monoxide poisoning. Additionally, any return duct needs to be sizes at least 2 inches larger than the main duct entrance and its SP added to the system total. Additionally, OSHA and other applicable safety regulatory bodies require any recirculated air to pass through a HEPA after filter.
Combustible Dust and/or Toxic Compounds Hazards
Many types of dust, including many woods are toxic, so take special care to choose a filtering system that will provide optimal safety. Facilities that handle combustible dusts must take special precautions to avoid potentially serious safety hazards from forming within their dust collection system. The National Fire Code issued by the NFPA (National Fire Protection Agency), OSHA combustible dust emphasis program, and the OSHA General Duty Clause and many other similar local and state regulations now require a combination of explosion/fire prevention and/or protection devices for any dust collection system handling combustible dusts. Prevention devices include spark arrestors, abort gates, high-speed sprinklers, inert gas or injection systems, and more. Protection devices include explosion vents, high-speed sprinklers and dry extinguishing injection systems. Fire experts should be consulted for any system potentially handling combustible dusts.
Filter Styles
New filter styles such as pleated filter elements can improve operation, reliability and collection efficiency while also lower operating costs (less compressed air to clean, last longer) compared to traditional bag and cage technology. They also allow for much smaller units (thus cheaper to build) while still having better air to cloth ratios compared to bags since they also provide more filter cloth in a smaller area.
Bags, cartridges or pleated filter elements are three common filter styles used in baghouse dust collectors. Cartridges are rarely used in new systems except for a handful of OEMs due to high cost and difficulty sourcing replacements. Bags and cages are the most versatile being able to work in the widest range of applications including temperatures up to 500F. In newer systems, pleated filter elements (sometimes called pleated filters) provide a much larger filter cloth area in a smaller space compared to bags (usually 3 times as much filter in half the space). They are widely manufactured and are only marginally more expensive than bag and cages. In addition, they provide superior performance, require less cleaning energy (i.e. compressed air) and provide less pressure drop over a longer service life. And due to their smaller size, collector units can be made smaller. (See our case study showing benefits of converting from bag/cage technology to pleated filter elements)
Best Practices to Increase efficiency and Reduce Size
Try to capture dust as close as possible to source to reduce size requirements. More directed venting better solution than venting large area as volumes increase rapidly when venting entire spaces e.g. Venting one machine at 600 CFM = 6 bag unit vs. venting entire room of 30’ x 30’ x 10’ = 9,000 cubic feet of air = 125 bag unit @ 3:1 ratio Oversizing for future expansion Good idea to size in additional 10% capacity for later. Minimal added costs upfront to add additional capacity, resizing later much more expensive (10:1 ratio roughly)
Balancing System Using Blast Gates
Blast gates should be installed on all branch lines to maintain system balance. Their proper use should also be part of regular training for dust collector operation.
Clean Out Traps
If your system has areas where long slivers of material could possibly hang-up and cause a clog, install a clean-out near that area.
Determining Required Capacity For Secondary Sources
Various options exist for disposing of dust from the baghouse hopper. Here are 6 discharge methods
After adding all primary lines together determine how much extra capacity you want to install for secondary lines. If secondary branches are run sparingly then its possible to not include them in the calculation. When they need to be used you can divert some of the capacity from the primary branches (by shutting them down and blocking those ducts using a damper valve). Be realistic when calculating your needs and size appropriately.
Consider Variable Frequency Drive (VFD) Fans
VFD fans allow for more control over system performance and potential energy savings when loads constantly change.
Dust Discharge Options
The most basic discharge is a manual slide gate, that is activated manually by personnel. If dust loads are light or the system is infrequently used this may be the most economical option. However, failure to keep the baghouse hopper clean and result in major operational problems and damage the filters. Another option is for a rotary airlock that automatically cleans the hopper. This eliminates the need for a technician to manually clean the hopper, but comes at a price tag in the $2,000 – $3,000 range.
Ready To Size Your Dust Collection System?
Thank you for reading our online guide to sizing your dust collection system. After considering this information should be able to estimate what size dust collection system your facility needs. With this information in hand you can begin the bidding process for your new system. Baghouse.com experts are ready to help if you have any questions. Please feel free to call at (702) 848-3990, contact us via our online form, or visit our resources section for more helpful dust collector information.
Baghouse Design Guide Overview
Pallet maker continues to expose workers to wood dust
Dust Collection Blog, SummaryA pallet maker based in Wisconsin has had another citation from the OSHA after some investigation reveals that it has continuously been exposing its workers to wood dust. The penalties that Avid Pallet Services LLC will face are to the tune of $188,302 for serious violations that are repeated related to safety and health of its workers. When inspectors checked the company’s premises, they determined that the company did not implement or failed totally to implement engineering controls that would reduce the exposure of its employees to wood dust, and was failing in its ability to train its employees on the health hazard of wood dust. But this citation is not the first for Avid Pallet Services. It has been cited before by the OSHA in 2016. It was reported that the company was not transparent in its treatment of its employments when it comes to workplace hazards. The OSHA director states that it regularly informs employers that they have to make employees aware of the health hazards related to their work and to manage it well. On a contrasting note, the author notes that Avid Pallet states that transparency and integrity is one of its guiding principles. This was also stated on their website.
Key Takeaways:
“Avid Pallet Services LLC faces penalties of $188,302 for repeated, serious, and other-than-serious safety and health violations.”
Read more: https://www.ishn.com/articles/110522-pallet-maker-continues-to-expose-workers-to-wood-dust
Course is set for A+A 2019 Occupational Health and Safety Trade Fair
Dust Collection Blog, SummaryOn November 5-8, 2019, there will be an A+A International conference that will be held in Dusseldorf, Germany, on Safety, Security, and Health. Mess Dusseldorf has been responsible for the A+A Conference and the man in charge of affairs is Wolfram Diener who has been the Managing director of the agency since October 2018. From the interview held with him, one can see that Diener is super excited and enthusiastic about his new job. He considers this conference a challenge after successful fairs in other places and even in Asia. His company, Messe Dusseldorf, is seen as a robust and successful company in hosting trade fairs in Germany. When asked about the response to the fair from companies so far, Diener states that the response has been great. There has been considerable interest shown in the fair both from companies that have participated before and from new companies. To accommodate all companies, the space for the fair has been expanded. Additional capacities in the areas of health at Work, Operational Safety, and Corporate Fashion have been added. Diener goes on during the interview to demonstrate the arrangements that have been put in place for the fair.
Key Takeaways:
“Since October 1, 2018, Wolfram Diener has been the new Managing Director of Messe Düsseldorf and responsible for A+A. Diener is enthusiastic about his new job: “After many exciting and successful years with various trade fair companies, and quite some time in Asia, I am now facing the next challenge – and this challenge will be more than the bandwidth of my trade fair portfolio in Düsseldorf.”
Read more: https://www.ishn.com/articles/110640-course-is-set-for-aa-2019-occupational-health-and-safety-trade-fair
Real-time dust monitor launched
Dust Collection Blog, SummaryDepending on one’s place of employment, the particles that can be found in dust often contain harmful materials that can result in dangerous situations, some of these situations being fatal. Since these hazardous conditions can be hard to detect with the human eye, many companies are now employing real-time monitors that have the ability to detect any harmful particles so that they are addressed before it develops into a bigger issue where someone is potentially put in harm’s way.
Key Takeaways:
“The real-time application also allows companies to use live data to identify specific trends and peak levels of risk.”
Read more: https://www.shponline.co.uk/occupational-health/real-time-dust-monitor-launched/
Safety gaps led to explosions at Mississippi gas plant: CSB
Dust Collection Blog, Industrial Health and Safety, Pollution/Emission Regulation, Safety, SummaryIn July of 2016, the mismanagement of a heat exchanger led to an extensive series of explosions that resulted in damaging forest fires in Mississippi. The mismanagement was a result of Enterprise Products Pascagoula Gas Plant allowing the equipment to experience too much thermal fatigue. If there had been more extensive safety measures and inspection protocols set in place, these disastrous results may not have occurred, saving a plethora of vegetation and clean up funds.
Key Takeaways:
“The plant – which had repaired four heat exchangers nine times in 17 years, CSB found – was shut down for nearly six months.”
Read more: https://www.safetyandhealthmagazine.com/articles/18103-safety-gaps-led-to-explosions-at-mississippi-gas-plant-csb
Discarding Paradigms that Limit Our Ability to Prevent Slip, Trip and Fall Injuries
SafetyWhen trying to reduce trip hazards, a paradigm shift is needed. It is believed that personal awareness is necessary for prevention, but this does not take into account that walking is an automatic function for humans. Next, we look to shoes, but discount the fact that soles wear out. When it comes to signs, they may help when new, but they quickly become invisible. Preventing slips and falls should be easy, but we need to be willing to dig deeper to find the real cause of slips and falls.
Key Takeaways:
“This should be our wake-up call to discard these commonly held paradigms that have for years impeded our effectiveness as safety people to actually prevent slip-and-trip injuries.”
Read more here:
http://www.ehstoday.com/ppe/discarding-paradigms-limit-our-ability-prevent-slip-trip-and-fall-injuries
Strategic management: 8 steps to success
Dust Collection BlogA proper strategy when managing an industry is key to it’s success and flourish. Bringing employees to think and operate on a similar level is not an easy task, especially when management teams aren’t well equipped to get employees to think and work on a justly productive level. Steps to ensure an industry’s success are outlined with specific examples that pertain to management teams and individuals all the same.
Key Takeaways:
“To be successful, an organization must integrate all the elements that drive optimal asset performance.”
http://www.plantengineering.com/single-article/strategic-management-8-steps-to-success/37e2626e6b4138002ca0bd30a40af136.html
Rewarding operational improvement: Target changes, not just numbers
Dust Collection BlogRewarding individual operators and operations as a group means recognizing them for their performance and acknowledging them for their contributions to the goals of their organization. Group recognition is usually tied to lagging metrics. Asset reliability is a good example of this. It is important to indicate the key performance indicators.
Key Takeaways:
“Proactive operators are innovative problem solvers.”
http://www.plantengineering.com/single-article/rewarding-operational-improvement-target-changes-not-just-numbers/857e18c1f60359446ba707c3c5b9ccbe.html
Purchasing Filters & Cages: Inventory Management for Dust Collection System Parts
Dust Collection BlogPurchasing Filters & Cages: Inventory Management for Dust Collection System Parts
A Quick Guide for Purchasing Professionals
Purchasing consumable parts for industrial systems like filters and cages for a baghouse dust collector can be a challenge. Part of the job of a purchasing professional, supply chain manager, or material planner is to ensure there are enough parts on hand so they will be available when needed, while minimizing inventory and expedite costs.
You certainly don’t want to wait until your dust collector goes down due to a damaged filter or a required changeout to go out and try to purchase filters and cages – lead times can vary wildly (up to 16 weeks for some specialty items) due to global raw material availability, supply chain issues, and the general demand for your item. Ensuring your supply of parts comes down to inventory management.
Every supply chain professional understands the basic concept of inventory management and safety stock, but how should you ensure you have the correct inventory for your dust collection system parts (generally, filters and cages)?
Here’s a general process that you can follow:
Reorder Point = (Lead Time x Average Demand) + Safety Stock
The safety stock is the additional inventory that you keep on hand to cover unexpected demand or supply chain disruptions.
EOQ = sqrt((2 x Annual Demand x Ordering Cost) / Holding Cost)
Where:
Reorder Frequency = Annual Demand / EOQ
Would you like help understanding current lead times for your filters, cages, and other dust collection system parts?
Contact Us Today to Talk to One of Our Baghouse Experts.
Which Baghouse Hopper Discharge Method Is Best?
Baghouse FAQs, Dust Collection BlogMany problems arise over how to properly dispose of dust in the baghouse once it is collected. Improper dust disposal can directly impact the operation of your baghouse. Storing dust in your baghouse hopper is a terrible idea. Dust collector hoppers are designed for temporary storage only. If collected dust builds up in the hopper it can cause several problems.
Clearly, failure to keep the discharge working efficiency can have serious consequences. So how can you make sure your discharge system meets the needs of your baghouse?
Get a free quote on baghouse filters!
Let’s review a few common dust discharge methods and some guidelines for choosing the best option for your application.
#1, 3 – Covered Box or Drum with venting
An enclosure (usually a box or container) directly underneath the discharge holds the dust. To prevent dusting and back pressure issues the enclosure is vented by (a) a small vent with filter attached to it or (b) with a duct vent piped back to the collector or the inlet duct. Simple system, but requires maintenance to remove collected dust or else it can backup into the discharge (blocking the system) and overflow the container. Good for systems with light dust loads and nonhazardous materials.
#2, 5, 6 – Removable Storage Containers
Uses drums or bags to collect dust from discharge. When filled, technicians remove them by hand or using a forklift for disposal and then replace them with a new container. Good choice for easily handled, non-toxic dusts. Can also be useful for products that then get shipped by truck from plant (e.g. fly ash sold to cement plants, etc.) Requires technicians to monitor fill levels and replace as needed.
The most common automated dust transport method for baghouse discharges is by screw conveyor
#4 – Discharge to conveying system
Preferred where possible, this method ensures the prompt removal of discharged dust. This proves the best solution for large units with heavy dust loads and applications requiring dust to be transported far from the collector after disposal such as hazardous material disposal, or for reuse in process. On the downside, it is more expensive than other methods and requires additional maintenance costs to maintain system.
Conclusion
We have seen that the best method of hopper discharge varies from application to application and from unit to unit. However, this does not mean that all discharge methods work for all baghouses. As outlined above, serious problems arise when the baghouse hopper discharge system is not adequate to the dust loads passing through the unit. Additionally, the disposal methods may require more man power than available at the plant and lead to spillage and other issues.
These issues can be avoided by not leaving the dust discharge method to chance. Review the operating parameters, dust loading rates, dust characteristics and eventual use of the dust (including disposal in landfill) before selecting a discharge method.
Baghouse.com has helped many plants retrofit their existing dust collectors with new hopper discharges, dust transportation and removal. Contact us today and let us advise you on how to improve your discharge system and thereby improve your dust collector efficiency today!
Need Help With Your Hopper Discharge?
Baghouse.com has helped many plants retrofit their existing dust collectors with new hopper discharges, dust transportation and removal. Contact us today and let us advise you on how to improve your discharge system and thereby improve your dust collector efficiency today!
Additional Considerations for Dust Collection System Design (Part 4 of Design Guide)
Baghouse Design, Dust Collection BlogIn this design guide we have reviewed a relatively simple baghouse dust collection system with few variables. Even at this level it is still recommend to consult with an experienced dust collector OEM like Baghouse.com before making any equipment purchase. There may be additional factors to consider before determining the final sizing, design, construction and installation of a dust collection system.
Common Additional Considerations
Recirculating Air Back Into The Facility
Recirculating air from the dust collector exhaust can prove practical in areas with cold climates to conserve heat. Make sure to include a ambient air return line to balance the airflows and prevent carbon monoxide poisoning. Additionally, any return duct needs to be sizes at least 2 inches larger than the main duct entrance and its SP added to the system total. Additionally, OSHA and other applicable safety regulatory bodies require any recirculated air to pass through a HEPA after filter.
Get help with your dust collection system now!
Combustible Dust and/or Toxic Compounds Hazards
Many types of dust, including many woods are toxic, so take special care to choose a filtering system that will provide optimal safety. Facilities that handle combustible dusts must take special precautions to avoid potentially serious safety hazards from forming within their dust collection system. The National Fire Code issued by the NFPA (National Fire Protection Agency), OSHA combustible dust emphasis program, and the OSHA General Duty Clause and many other similar local and state regulations now require a combination of explosion/fire prevention and/or protection devices for any dust collection system handling combustible dusts. Prevention devices include spark arrestors, abort gates, high-speed sprinklers, inert gas or injection systems, and more. Protection devices include explosion vents, high-speed sprinklers and dry extinguishing injection systems. Fire experts should be consulted for any system potentially handling combustible dusts.
Filter Styles
New filter styles such as pleated filter elements can improve operation, reliability and collection efficiency while also lower operating costs (less compressed air to clean, last longer) compared to traditional bag and cage technology. They also allow for much smaller units (thus cheaper to build) while still having better air to cloth ratios compared to bags since they also provide more filter cloth in a smaller area.
Bags, cartridges or pleated filter elements are three common filter styles used in baghouse dust collectors. Cartridges are rarely used in new systems except for a handful of OEMs due to high cost and difficulty sourcing replacements. Bags and cages are the most versatile being able to work in the widest range of applications including temperatures up to 500F. In newer systems, pleated filter elements (sometimes called pleated filters) provide a much larger filter cloth area in a smaller space compared to bags (usually 3 times as much filter in half the space). They are widely manufactured and are only marginally more expensive than bag and cages. In addition, they provide superior performance, require less cleaning energy (i.e. compressed air) and provide less pressure drop over a longer service life. And due to their smaller size, collector units can be made smaller. (See our case study showing benefits of converting from bag/cage technology to pleated filter elements)
Best Practices to Increase efficiency and Reduce Size
Try to capture dust as close as possible to source to reduce size requirements. More directed venting better solution than venting large area as volumes increase rapidly when venting entire spaces e.g. Venting one machine at 600 CFM = 6 bag unit vs. venting entire room of 30’ x 30’ x 10’ = 9,000 cubic feet of air = 125 bag unit @ 3:1 ratio Oversizing for future expansion Good idea to size in additional 10% capacity for later. Minimal added costs upfront to add additional capacity, resizing later much more expensive (10:1 ratio roughly)
Balancing System Using Blast Gates
Blast gates should be installed on all branch lines to maintain system balance. Their proper use should also be part of regular training for dust collector operation.
Clean Out Traps
If your system has areas where long slivers of material could possibly hang-up and cause a clog, install a clean-out near that area.
Determining Required Capacity For Secondary Sources
Various options exist for disposing of dust from the baghouse hopper. Here are 6 discharge methods
After adding all primary lines together determine how much extra capacity you want to install for secondary lines. If secondary branches are run sparingly then its possible to not include them in the calculation. When they need to be used you can divert some of the capacity from the primary branches (by shutting them down and blocking those ducts using a damper valve). Be realistic when calculating your needs and size appropriately.
Consider Variable Frequency Drive (VFD) Fans
VFD fans allow for more control over system performance and potential energy savings when loads constantly change.
Dust Discharge Options
The most basic discharge is a manual slide gate, that is activated manually by personnel. If dust loads are light or the system is infrequently used this may be the most economical option. However, failure to keep the baghouse hopper clean and result in major operational problems and damage the filters. Another option is for a rotary airlock that automatically cleans the hopper. This eliminates the need for a technician to manually clean the hopper, but comes at a price tag in the $2,000 – $3,000 range.
Ready To Size Your Dust Collection System?
Thank you for reading our online guide to sizing your dust collection system. After considering this information should be able to estimate what size dust collection system your facility needs. With this information in hand you can begin the bidding process for your new system. Baghouse.com experts are ready to help if you have any questions. Please feel free to call at (702) 848-3990, contact us via our online form, or visit our resources section for more helpful dust collector information.
Need Help Designing Your Baghouse System?
Looking for help designing your dust collection system? Let our us use our 40+ years of expertise to help you select the right system for your application.
Baghouse Design Guide Overview