This website requires certain cookies to work and uses other cookies to help you have the best experience. By visiting this website, certain cookies have already been set, which you may delete and block. By closing this message or continuing to use our site, you agree to the use of cookies. Visit our updated privacy and cookie policy to learn more.
This Website Uses Cookies
By closing this message or continuing to use our site, you agree to our cookie policy. Learn More
This website requires certain cookies to work and uses other cookies to help you have the best experience. By visiting this website, certain cookies have already been set, which you may delete and block. By closing this message or continuing to use our site, you agree to the use of cookies. Visit our updated privacy and cookie policy to learn more.
ISHN logo
search
cart
facebook twitter linkedin youtube
  • Sign In
  • Create Account
  • Sign Out
  • My Account
ISHN logo
  • Home
  • Magazine
    • Current Issue
    • Digital Editions
    • Archives
    • Buyer's Guide
    • Subscribe
  • Topics
    • Environment
    • Environmental Health and Safety
    • Government Regulations
    • Health
    • Industrial Hygiene
    • Occupational Safety
    • PPE
    • Product Case Studies
    • Psychology
    • Safety Culture
    • Training
    • Transportation Safety
    • More Topics
  • Construction
  • Oil & Gas
  • Columns
    • Editorial Comments
    • Best Practices
    • Positive Cultures
    • Training Strategies
    • Closing Time
    • FR Protection
    • Thought Leadership
  • Products
  • Conventions
    • Convention Companion
  • Multimedia
    • eBooks
    • Infographics
    • Photo Galleries
    • ISHN Podcasts
    • Your Digital Mentor Podcasts
    • Videos
    • Webinars
    • White Papers
    • ISHN YouTube Videos
  • More
    • Awards
      • 2020 Readers' Choice Awards- Submit Products
    • eNewsletters
    • Events
    • ISHN Store
    • Product Case Studies
    • Product Innovations
    • Showrooms
    • Vendor News
  • Advertise
    • Contact
Home » Active & passive explosion protection systems for dust collectors
Facility SafetySafety Technology

Active & passive explosion protection systems for dust collectors

Dust collection and explosion protection
March 12, 2018
Rick Kreczmer and Jon Ladwig
KEYWORDS Combustible dust / dust collection / ventilation systems
Reprints

An explosion is a serious risk at many manufacturing, processing and metalworking plants, and it can even stem from a dust collection system that’s protected incorrectly. NFPA 68 Standard on Explosion Protection by Deflagration Venting applies to the design, location, installation, maintenance and use of devices and systems that vent combustion gases and pressures resulting from a deflagration within an enclosure in order to minimize structural and mechanical damage.

The standard’s safety objective is to prevent structural failure of the occupied enclosed areas and minimize injury to personnel in areas adjacent to the enclosed space. Whether you vent your dust collector outdoors or indoors, proper design is crucial to deflagration protection.

Outdoor explosion venting

A passive deflagration protection system reacts to an event, while active systems detect and react prior to or during an event. A passive system can control explosions to keep employees safe and minimize equipment damage in the plant. A common, cost-effective passive method is venting; an active system involves more expensive technology and typically requires recertification on a regular schedule.

A well-designed explosion vent opens when the collector’s interior reaches a predetermined pressure, allowing the excess pressure and flame front to exit to a safe area. In the event of a deflagration, explosion venting can prevent the collector from reaching high levels of pressure that would cause the housing to fragment and create projectiles that would cause destruction, thereby reducing the hazards to personnel and facilities. When the dust collector is located outside, it must be designed to vent away from buildings and populated areas.

While explosion venting will usually save the dust collector from being a total loss, the collector can still sustain damage. A thorough inspection of the entire dust collection system should be made paying close attention any damage to bolted components like fans, ductwork or door hardware, housing and tube sheet, and filter integrity. Nonetheless, if personnel remain safe, the explosion venting equipment has done its job.

Indoor flameless venting devices

NFPA 68 allows flameless venting inside buildings when venting outdoors is not feasible or desirable. For example, you may need to locate your dust collector indoors without access to an outside wall or without the ability to vent through the ceiling.

Flameless venting devices allow you to vent an explosion safely indoors without allowing any flame and a minimal pressure front to escape from the collector. Work with the manufacturer of your device to determine the correct safety zone.

Devices that meet this standard are commercially available in various configurations. Although flameless devices for quenching explosions is a viable option to ducted explosion vents, it’s not recommended for toxic dust applications because dust can be released into the room where venting occurs.

Ductwork protection

NFPA requires protection for the ductwork and safety processes upstream of the dust collector. Equip the ducting with a flow-activated isolation valve protecting downstream work areas and processes from the propagation of flame and pressure through the inlet duct when deflagration occurs in a dust collector. The pressure wave will close the valve during deflagration in a dust collector, preventing flame and smoke to pass to areas upstream from the valve.

Active explosion suppression systems

If it’s not feasible to duct an explosion to the outside through a wall or ceiling in your dust collection application, you’ll need an explosion suppression or suppression-isolation system. Suppression methods are covered in NFPA 69: Standard on Explosion Prevention Systems. NFPA 69 extends beyond explosion venting to address the whole dust collection system — inlet and outlet ducting, spark-extinguishing systems and methods for preventing an explosion from traveling back into the building.

Active explosion suppression solutions include:

  • Chemical isolation: Designed to react within milliseconds of detecting an explosion, a chemical suppression system can be installed in either inlet and/or outlet ducting. Typical components include explosion pressure detector(s), flame detector and a control panel. This system creates a chemical barrier that suppresses the explosion within the ducting and reduces the propagation of flame.
  • Chemical suppression: Whereas chemical isolation is used to detect and suppress explosions within the ducting, chemical suppression protects the dust collector itself. It is often used, together with isolation, when it is not possible to safely vent an explosion or where the dust is harmful or toxic. The system detects an explosion hazard within milliseconds and releases a chemical agent to extinguish the flame before an explosion can occur.
  • Fast acting valve: Designed to close within milliseconds of detecting an explosion, the valve installs in either inlet and/or outlet ducting. It creates a mechanical barrier within the ducting that effectively isolates pressure and flame fronts from either direction, preventing them from propagating further through the process.
  • High-speed abort gate: The gate is installed in the inlet and/or outlet ducting of a dust collection system and is used to divert possible ignition hazards from entering the collector, preventing a possible explosion from occurring and preventing flame and burning debris from entering the facility through the return air system.

Because combustible dust issues are complex and incidents can be devastating, it’s important to use an experienced independent professional engineer to help you design and install your system. That way you can be certain that your facility complies with NFPA requirements and those of your local fire marshal and insurance carriers. You can view or purchase a copy of Standard 68 and Standard 69 on NFPA’s website.

Subscribe to ISHN Magazine

Recent Articles by Rick Kreczmer

ANSI/ASHRAE Standard 199 improves industrial dust collection

How to find the best filter cartridges

Rick Kreczmer has held numerous positions with Camfil APC in the U.S. and Europe, and currently serves as aftermarket sales manager. The author can be reached at 800-479-6801, 870-933-8048, or filterman@camfil.com.

Jon Ladwig is a metal industry specialist for Camfil Air Pollution Control (APC). Camfil APC is a global manufacturer of dust, fume and mist collection equipment and is part of Camfil, the largest air filter manufacturer in the world. Telephone 800-479-6801 or 870-933-8048; www.camfilapc.com.

Related Articles

Control dust and fumes in metalworking and welding operations

High efficiency dust collector offers compact design, cleanable filter system, explosion protection

Related Events

Proof Of Performance Testing For Industrial Ventilation Systems webinar

Subscribe For Free!
  • Digital Edition Subscriptions
  • ISHN eNewsletter & Other eNews Alerts
  • Online Registration
  • Subscription Customer Service

More Videos

Popular Stories

Today's News

2 young part-time UPS workers killed in California

Today's News

Steel worker injured at Indiana plant

crystal ball

Safety and health trends for 2020

Tesla

Report finds worker injuries are “routine” at Tesla’s Nevada plant

Lendlease

Humorous workplace safety campaign features mothers

ISHN Readers' Choice Awards 2020 product submissions


Events

March 7, 2019

Safety and Wellness: The Combination that Drives Engagement and Profitability

On Demand Attend this webinar for the keys to success, as well as mistakes to avoid, when targeting safety and wellness with a Recognition & Reward Program.

View All Submit An Event

ISHN Podcasts


ISHN Podcasts

ISHN Magazine

ISHN1219_cover.jpg

2019 December

Among the articles in the December 2019 issue of ISHN Magazine, we have expert insight on selecting the right respirator, a link to the 2020 Buyers’ & Resource Guide, 10 safety mistakes that can land you in a courtroom, and much more.
View More Create Account
  • Resources
    • List Rental
    • Safety A-Z
    • Custom Content & Marketing Services
    • Market Research
    • Web Exclusives
    • Privacy Policy
  • Want More
    • Connect
    • Subscribe
    • Survey And Sample

Copyright ©2019. All Rights Reserved BNP Media.

Design, CMS, Hosting & Web Development :: ePublishing