If you need to prevent a dust collector explosion in your facility, following NFPA standards will guide you in the right direction. NFPA 69 Standard on Explosion Prevention Systems covers many different methods for preventing explosions.
This standard covers many types of explosive materials, but we’ll focus on the parts that apply to dust explosion prevention and dust collection systems. Also, many types of dust have a specific NFPA standard of their own (woodworking, agriculture, etc). Any of these industry-specific standards will take precedence. We’ll review them later in the series.
What NFPA 69 Says About Dust Collector Explosion Prevention
NFPA 69 specifies the requirements for explosion prevention. It also reviews options for different situations. Only some of them are relevant to dust collection. All methods require the owner or operator to keep records of the system’s maintenance and functioning.
IMPORTANT NOTE: A deflagration is a fire or flame front. It may be moving fast, but not as fast as an explosion. An explosion moves faster than the speed of sound and creates very high pressure. Devices built to handle a deflagration may not be designed to handle a dust collector explosion.
Pre-deflagration and control of ignition sources:
Using an optical or another kind of sensor to detect a spark or burning material
An automatic device triggered by the sensor diverts or extinguishes the hazard
Only acceptable for ignition sources like sparks, NOT a solution to a fire already happening
Deflagration Control by Active Isolation:
Actively stopping or controlling a fire that is already ignited
Can also include chemical isolation (chemical fire extinguishment)
Must include a method of fire or pressure detection to activate
Deflagration Control by Passive Isolation
Includes in-line deflagration arrestors like the CMAXX IDA
Act independently of the active explosion prevention devices
Create a barrier that will stop a flame front
NFPA 69 Standard for Explosion Prevention Systems also reviews the standards and best practices for system design and installation. The details depend on your dust and which types of deflagration and explosion control you plan to use.
Dust Explosion Prevention Challenges
Dust, fumes, and other fine particles pose a special challenge for preventing fire or explosions. That makes it even more important to work with someone who has experience with your type of dust. The type of prevention your system needs might be very different from someone else’s.
For example, a spark arrestor’s job is to decrease the chance of sparks getting through to the collector. This works very well for applications like metal fume dust from welding or cutting.
However, spark arrestors are a terrible idea for woodworking applications. Wood dust accumulates inside spark arrestors, so a spark might start a fire instead of being put out.
Types of chemical isolation or extinguishment can also vary depending on your material. A standard chemical fire extinguisher might put out many fires. However, on a metal dust fire like aluminum or magnesium, only a Class D extinguisher will work. Water or the wrong extinguisher can cause the fire to grow explosively.
NFPA 69 and Other Combustible Dust Standards
The challenges of combustible dust handling led to the development of NFPA 652 and 654, standards specific to combustible dust. Sometimes these two will refer to NFPA 69. With NFPA standards, though, the standard that’s specific to the industry or topic takes precedence over the more general one.
In other words, the NFPA 651 Standard for the Machining and Finishing of Aluminum and the Production and Handling of Aluminum Powders gives instructions specific to aluminum. This should be your go-to standard if you deal with aluminum dust.
Fortunately, NFPA works hard to make sure the standards are up to date. They don’t usually conflict with each other, so your industry-specific standard may just be more specific or have some helpful details. NFPA 69 is still the gold standard for information about explosion prevention.
Some industries like agriculture and woodworking create unusual dust challenges. You should be aware of the industry-specific standards that relate to your workplace Fortunately, we’re going to cover some of those in the fourth episode of this series, so check back if you’d like to learn more!
According to NFPA standards, explosion venting is a key part of dust collector safety. NFPA 68, the Standard on Explosion Protection by Deflagration Venting, lays out these guidelines. Dust collector explosion venting, also called deflagration venting, allows pressure to safely escape during a fire.
Without explosion relief venting, a dust collector fire can cause a rapid increase in pressure inside the enclosed space. Then, with no safe outlet, the growing pressure can damage the dust collector or even the entire facility. So it puts lives at risk.
What NFPA 68 Says About Explosion Venting for Dust Collectors
NFPA 68 specifies what explosion venting must do to meet standards. Firstly, the explosion or deflagration venting must protect people from harm:
Prevent structural failure that causes harm to people in the area
Direct venting away from the presence of people in the area
Make sure that materials that are health hazards vent outside
Secondly, the venting must prevent property from damage:
Limit damage to the enclosure by venting pressure
Avoid ignition of nearby items or property
Direct projectile materials away from potential damage
In other words, the force of the deflagration or explosion needs to vent away from people or things that it could damage. Also, the vent design must not result in pieces of material being flung into the neighbor’s office building in the event of an explosion.
The Dust Collector Explosion Pentagon
Why do dust collectors in particular need explosion venting?
For an explosion to occur, the five elements of the dust explosion pentagon must be met. A dust collector is a perfect place for all five of these things to happen.
First of all, if you have combustible dust, you have fuel for a fire. Then, if that dust disperses in air, as it would in a dust collector, it is much more explosive. Next, assuming the dust collector has air inside it, the fire has oxygen. Then a spark, electrical component, or overheated piece of equipment can provide the ignition. Finally, to make it a true explosion, the dust cloud is inside an enclosed space.
That enclosed space creates the biggest danger in combustible dust collection. With all five elements of the pentagon met, the dust collector becomes an enclosed space full of oxygen and fuel. One spark can cause ignition.
In a dust collector without proper explosion relief venting, fuel burning in the closed space will create a rapid increase in pressure. With no escape, the pressure will create its own path to vent. Injury to people and damage to property may result.
By using the appropriate dust collector explosion venting that meets NFPA 68 standards, that pressure has a safe exit. Designed to rupture when pressure builds, the vent provides the easiest escape route for the gasses and flames.
Most cars built today have a “crumple zone”. This area of the car absorbs the force of impact by acting as a weak point, designed to take the damage so the rest of the car doesn’t. An explosion vent for your dust collector acts in a similar way: by design, it’s the weak point, the place that will rupture before the rest of the dust collector does.
Explosion Vent Design and Options for NFPA 68
NFPA 68 gives formulas to calculate the exact size of an explosion relief vent for dust collectors. If it’s not feasible to point the vent in a safe direction, standards allow for the use of a blast deflector plate. This plate will usually face the vent at an angle of somewhere between 45 degrees and 60 degrees. The blast deflector plate must take the full force of the vented explosion and redirect it.
Dust collectors located indoors usually have ductwork that vents to the outdoors. NFPA 68 allows this as long as the ductwork is strong enough to withstand the potential damage. Sometimes, though, an indoor dust collector has no vent to the outside. In this case, you have an option, but not a cheap one.
Flameless explosion vents, as the NFPA defines them, act as flame arrestors, completely stopping flames. They also provide particulate retention, which means that no particles or flaming material can get through. These deflagration venting devices will add significant expense to a dust collection project.
The most common type of explosion relief on dust collectors is an explosion vent, also sometimes called a burst panel. An attached burst detector can tell you whether the panel has been subjected to enough force to burst it, even if it looks OK. Even minor damage to the explosion vent means the dust collector could have been subjected to internal pressure. This means it must be checked for any other damage.
Other NFPA Standards for Dust Collector Explosion Venting
Most other NFPA standards relating to explosion venting refer back to NFPA 68. It contains the most detailed standards and calculations. However, some materials use special equipment or present special challenges. If your facility handles combustible dust, you’ll need to be aware of several other standards:
Fundamentals of Combustible Dust: NFPA 652
Prevention of Fire and Dust Explosions from the Manufacturing, Processing, and Handling of Combustible Particulate Solids: NFPA 54
Explosion Prevention Systems: NFPA 69
The first two standards combine a lot of the information once scattered across other standards. NFPA 69, the sister standard to NFPA 68, covers many explosion prevention and control systems. Many NFPA standards deal with very specific industries or materials:
Prevention of Fires and Dust Explosions in Agricultural and Food Processing Facilities: NFPA 61
Combustible Metals: NFPA 484 (separate standards exist for aluminum, lithium, magnesium, titanium, and zirconium)
Prevention of Fires and Explosions in Wood Processing and Woodworking Facilities: NFPA 664
For more information about these NFPA standards, keep an eye on our future blog posts by following us on Facebook or Linkedin so you don’t miss any useful information!
This is the first episode of our monthly podcast on industry safety and dust collection. In this episode Donovan and Justin go over some of the topics that we will cover on in future episodes. They talk safety, products, news and more. Also they mention the industry leaders that will be guests on the show as well as some on-site recordings at different trade shows. We are all very excited about the future episodes and can’t wait for you to hear them. Breathe Better, Work Safer.
TRANSCRIPT
Welcome to the Dusty Jobs podcast from Imperial Systems, industry knowledge to make your job easier and safer.
DONOVAN: Hello, welcome to the Dusty Jobs podcast; this is our very first podcast. Today we are in Mercer, Pennsylvania at Imperial Systems headquarters. I’m sitting here with Justin Badger: how are you doing, Justin?
JUSTIN: Doing pretty good. I’m excited about this.
DONOVAN: Excited about our first podcast. For those of you who don’t know about Imperial Systems, we are a dust and fume collection equipment company. Justin, tell them what our mission statement is here.
JUSTIN: Our mission is to improve the health, safety, and quality of people’s lives by building the best dust and fume collectors on Earth.
DONOVAN: That’s right, and we’ve been doing that for 18 years now in the industry. We’ve been building products, helping install things…
JUSTIN: Absolutely.
DONOVAN: Helping people with full installations down to just replacement parts. We’ve been doing that for 18 years.
JUSTIN: Yeah, we’re excited in this podcast. That’s what we’re going to talk a lot about. We’re going to talk a lot about dust collection and how we can and how we do improve people’s lives.
DONOVAN: Right.
JUSTIN: By cleaning the air, basically.
DONOVAN: We’re going to be going beyond that, too.
JUSTIN: Absolutely. We have plans to talk about a lot of environmental health and safety topics, including many different OSHA-related things… ladder safety and compliance, and combustible dust safety.
DONOVAN: But it’s not going to be just you and me talking about this. We’re going to have other people on. Industry experts, going to some on-location places to meet up with some people to talk about different topics.
JUSTIN: We do different trade shows. We’ll be at GEAPS in March and have a couple of episodes that we’re going to record there about different topics that are related to the grain market. We’ll also do FABTECH, which is a metals manufacturing and fabrication show; we do that one every November. It’s in Las Vegas this year, so we’re really excited to have some industry experts, either environmental health and safety like we talked about before, or other machinery or equipment safety. So we have a lot of different ideas we’d like to talk about on this show. But how can people contribute on their own?
DONOVAN: Well, we’ve got a lot of different ways you’re going to be able to help tell us what you guys would like to hear. We’re going to get to those at the end of the podcast. But right now… what do you do here, Justin? What’s your role here at Imperial?
JUSTIN: I’m the national sales and marketing manager.
DONOVAN: There you go. My name’s Donovan Karki, and I’ll be helping to cohost this podcast. I do sales here at Imperial Systems, so now you know a little more about what we do and maybe a little bit more about what Imperial does. Like we said, we build products here, and I think Justin’s going to give us a little bit of a rundown on a brief equipment line of what we have. We’re not going to be talking about this all the time, but at least you know what we’re doing.
JUSTIN: We make a lot of different dust collection equipment. Some of our main pieces of equipment, of course there’s the CMAXX Dust and Fume Collector. That’s our flagship product. If you’ve heard of Imperial Systems before, you probably know the CMAXX dust collector. We also manufacture the BRF, which is a round baghouse, and a cyclone. We recently introduced the Shadow. We’re really excited about the Shadow dust collector, because there’s a lot of markets that it can fit into, such as laser cutting, like steel laser cutting, or robotic welding. I’m really excited about the robotic welding application because it’s growing. There’s not enough fabricators and stuff out there and a lot of companies are turning toward robots to fill that need, and when robots are doing the work they’re creating a lot of dust and fume, and the Shadow is perfect for filtering that dust in environmentally safety-conscious companies.
DONOVAN: Right, and we also handle other products. You know, for explosive dust, we have the Spark Trap, we have the Rhino Drum, we have… you know, just other accessories that go along with that. We can help with just about everything out there that’s in the dust collection world. I mean, what are all the things we help with? We can help with installation, we can help with product design…
JUSTIN: Absolutely. We are one of the only companies in the United States that can provide full turn-key solutions, from the initial quote to engineering and design to manufacturing the actual machinery, installing that machinery, and servicing the machinery on a follow-up.
DONOVAN: Now, we’re telling you about that because we want to let you know that we’re going to have people who cover all these topics coming on the podcast, talking about what they do. Everyone from installation to service techs to engineering aspects. And if you have any of those questions, you can let us know. You can let us know what you what you’d like to hear. We have industry leaders in all of those topics and all those categories that can come on and talk. What are some ways people could let us know about that? I know we’ve got an email address set up: it’s dustyjobspodcast@isystemsweb.com. Then we have social media… what are our social media sites?
JUSTIN: We’re on LinkedIn and Instagram, Facebook, Twitter… you can find us on any of those. DM us with some ideas we can do in future podcasts.
DONOVAN: Right.
JUSTIN: So one of the things I’m really excited about with this podcast is that most of the episodes are going to be on serious topics, but in the near future I’m really excited to have some people who have been in this industry for a long time, and if you’ve been in this industry long enough, there’s some pretty funny stories that they’ve done different dust collectors on, so that will be exciting to hear some of the history… I mean, thirty years ago, dust collection was done way different than it is today. It’ll be pretty interesting to learn a little bit about the history of dust collection…
DONOVAN: We even have some guys in our own shop that have been doing this for thirty years. They have some insight, have some stories, some things I’ve heard from them…
JUSTIN: There’s some interesting things that dust collectors are used on that people don’t even know about.
DONOVAN: Right.
JUSTIN: So it’s pretty cool. That’ll be a great episode to talk about, just a little light-hearted funny episode about some neat things.
DONOVAN: Yeah. I know one of the other episodes, we’re talking about having is possibly not just on the collector itself, but things that surround the collector. Safety… one of the topics we’ve just recently been talking about is ladder safety. I know we’re going to be covering some of that, and that can be really confusing at times.
JUSTIN: Absolutely.
DONOVAN: Different standards, OSHA and what it requires…
JUSTIN: Yeah, and one of the most important topics we’re going to cover is NFPA compliance for combustible dust. It is a hot topic right now, and with new regulations around dust hazard analysis, and then once you’ve done a dust hazard analysis, what do you do with that information for your needs in the future to make sure that you’re protecting your employees’ health and safety, your local community, and you know, the air we all breathe.
DONOVAN: It seems like weekly we’re reading stories, well, not weekly but monthly about some explosions that are happening because of just dust not being handled properly.
JUSTIN: We’re going to cover that for sure. It’s very important.
DONOVAN: We’re going to try to help get some information out there so that happens less.
JUSTIN: Yeah, that’s for sure. I’m looking forward to those ones.
DONOVAN: Yeah, and we’ve got a lot of other topics coming up. Like we said before, if you have anything you want to hear, let us know. We’re going to be excited to talk about those things. But as for today, I think that’s about all we have.
JUSTIN: Thanks for listening. We look forward to hearing from you about some different ideas.
DONOVAN: Drop us a line, let us know, look us up, and we’ll be coming back and hopefully talking on the things you guys want to hear about because you’ll let us know. Thanks for listening.
Thanks for listening to the Dusty Jobs podcast. Breathe better, work safer.
Dusty Jobs 11 is here! We here from a few of our folks about FABTECH 2019 in Chicago as well as the yearly sales meeting we had while there. We tell you more about one of our latest products introduced at FABTECH. Charlie tells us about dressing the part and his tie collection, and we here from welder Bob Kocher. If you would like a printed hard copy of this issue, contact an Imperial Systems, Inc representative.
Click the cover to download and print the newsletter.
A Letter from our Marketing Team
As a marketing team, we put each newsletter together hoping it will be interesting and fun for you. While everyone knows that Charlie’s “Good Luck With That” is always the star of the show, we also like to focus on a member of our team each time. We know that without the team who helped build this company, none of us would be here today.
Some of these people who have been on the cover probably would have laughed when they started a decade ago at the idea of us having our own marketing department. Doing business has changed a lot in the 18 years since this company began. Today, the marketing team handles everything from logo designs and videos to blog posts and informational publications. We’re even getting ready to add a podcast to help draw new potential customers.
Take a moment, as you enjoy this newsletter, to see how far we’ve come with our marketing efforts. It’s a never‑ending task, keeping up with all the changes, but it’s also a challenge that keeps things interesting.
Be prepared to watch us keep growing in 2020! We have big ideas and big plans. You’ll be hearing Jeremiah and some industry leaders talking us through some podcasts, and you’ll get to enjoy Mitch’s dulcet tones narrating more of our “Not Just a Box” video series. We’re exploring all the ways possible to reach out to people.
We’ll always be a company that builds the best dust and fume collectors on Earth, but as we step into the future we also need to be a company that makes an impact and inspires confidence.
If you have a cartridge dust collector, you’re probably aware of the compressed air pulses that clean the filters. Although our header tank design controls noise levels, the cleaning mechanism isn’t exactly silent. If the dust collector pulse cleans the cartridge filters during normal operation, why would you need to run an offline filter cleaning?
Offline cleaning of your cartridge filters can remove extra dust from the filters, improve efficiency, and increase filter life. Keep reading to learn how offline cleaning works and what it can do to keep those expensive cartridge filters in service longer.
What is offline filter cleaning?
Offline cleaning means cleaning the filters while the dust collector is not in operation. For some baghouses, the fan can only clean the bags when they are offline. These baghouses have separate sections, and one section goes offline for cleaning at a time. Because this means part of the baghouse needs to shut down often, the system operates less efficiently. Some baghouse designs to avoid this and clean all the filters while still in operation.
For cartridge dust collection systems, offline cleaning means pulsing the filters with compressed air while the system fan is shut off. With no air moving through the system, equal pressure exists on the clean air and dirty air side of the filters. No air is pulling through the filters.
Why is offline cleaning good for cartridge filters?
With the dust collection system online, the pulses of compressed air blow down through the cartridge filters to remove dust. At the same time, however, the air being cleaned moves in the opposite direction, upwards through the filters.
Online pulse cleaning keeps the filters working well while the dust collector operates. However, the compressed air pulse and the system airflow move in opposite directions. To get maximum cleaning power from the compressed air pulses, run a quick offline cleaning.
With the system shut down, no airflow blows back against the compressed air pulse. This lets it release more dust from the filters. Regular offline cleaning can extend filter life significantly by removing this extra dust.
What if we don’t have time for offline filter cleaning?
Taking your dust collection system offline for filter cleaning doesn’t have to take a lot of time. Our service technicians recommend that for offline cleaning, you manually pulse the filters twice. Often, you can do this in less than ten minutes of downtime.
Employee break time or lunchtime can allow you to shut your dust collector down for a short time. On a dust collector with an integrated control panel, manually running two compressed air pulses just takes the push of a button.
After a short offline cleaning, the cartridge filters should work more efficiently. While online cleaning will keep filters working, regular offline cleaning makes them last longer. Also, keeping the filters at maximum efficiency helps to protect HEPA or other expensive after-filters.
Need some personal advice about offline cartridge filter cleaning?
You can contact us here at Imperial Systems for advice on keeping your filters performing well. If you need more help or would like a hands-on education in dust collector maintenance, our ServiceMAXX team can pay a visit and help you establish a maintenance schedule.
If you take the time to run offline filter cleaning, you should see it pay off in longer filter life. Not only does this save money, but it also cuts down on the much longer downtime needed to replace old filters. If you have questions about how often you should run offline cleaning or any other questions about your dust and fume collection system, please contact us.
OK, stay with me for a minute. Any factory that produces dust needs some type of industrial factory dust control. Now, that dust from your factory processes may not eat all your leftover spaghetti or drive an obnoxiously loud car. But it does have some things in common with that guy your daughter keeps bringing around.
Without factory dust extraction, dust will settle and lay on every flat surface in your facility. Likewise, without a method for removal, the annoying boyfriend will find a flat surface, sprawl out on it, and stare at his phone. If you don’t capture dust at the source, it will escape into the factory and become a cleanup problem. In the same way, if you don’t deter the annoying boyfriend at the front door while attempting to enter, he will come inside, hog the Netflix, and mumble about memes he saw on Instagram.
See? They do have something in common.
Factory Dust Collection: Will It Remove Annoying Teenagers?
Unfortunately, an industrial dust collection system will not remove your daughter’s annoying boyfriend. It will, though, extract dust and fumes. In many factories, dust control comes down to basic housekeeping, like sweeping or vacuuming up dust.
Unfortunately, poking the annoying boyfriend with a broom will not get rid of him. Vacuuming his face with a shop vac seems to be frowned upon. Brooms and shop vacs in your factory will spread dust around, but not remove much of it. If you want to really control dust (or your daughter’s boyfriend), you can’t just move it around.
Unlike boyfriends, who usually settle on couches, airborne dust settles on beams, overhead lights, and other places almost impossible to reach with basic cleaning. In the event of an explosion, this dust can shake loose and disperse in the air. This can cause a deadly secondary explosion when this loose dust ignites.
(Side note: if you attempt to force your daughter’s boyfriend to become airborne, your daughter will probably create an emotional explosion, which you will then have to deal with.)
Dust Collection and Control
Once that boyfriend is in the door and sprawled in your living room eating your last blueberry muffin, you’re going to have a hard time getting rid of him. And once dust covers your factory, you’ll have an uphill battle trying to control it.
Fortunately, we can often identify where most of the dust originates. Many factories will have certain processes that put a lot of dust into the air. Examples include grinding, batch mixing, material transport, etc.
Source Capture
Installing an industrial dust collector allows you to capture dust or fumes at the source. This is called source capture and can use hoods, downdraft tables, or flexible fume arms.
Using source capture to control factory dust helps control worker exposure. This benefits people who work close to the machines. But it also benefits those in other areas of the factory from contaminants that can drift through the air.
Sadly, this method will not protect anyone from the horrific music that your daughter and her boyfriend contaminate your house with. The recommended solution for this problem is to use earplugs. If this method is not effective, covertly snipping a few wires and blaming it on mice can be useful.
Ambient Collection
Another option for industrial dust and fume collection in factories is an ambient system. This removes and cleans air from the entire facility. Many systems return the air to the facility after filtering it, which saves heating or cooling costs. For a factory that often has a haze of dust or fumes in the air, this type of system can clear things up effectively.
This type of system will not remove annoying teenage boyfriends. But it could be used to remove dirty t-shirt odor, smoke from over-microwaved pizza rolls, and teenage boy sneaker stench. An industrial dust and fume collection system wouldn’t be cost-effective for these purposes. So, you are probably stuck with air freshener and opening the windows.
A Safety and Health Issue
Factory workers may face serious health risks from exposure to dust and fumes. In addition, combustible dust creates an environment where a fire or explosion could occur. We won’t include any boyfriend jokes here, because combustible dust accidents cause fatalities every year in the United States alone.
If the boyfriend is inhaling some sort of harmful fumes, he’s probably doing it on purpose, but workers exposed to industrial dust and fumes don’t have a choice. A factory dust extraction system will remove those harmful materials from the work area.
Some factories use dust suppression, which usually means spraying a fine water mist to take the dust and fumes out of the air. This leaves damp dust accumulated around the facility that still needs to be cleaned up. While a sprinkler system can be a critical part of fire control, water misting doesn’t get dust out of the building.
(Side note: try misting the annoying boyfriend with water, which may be an effective deterrent, since it works on the cat.)
(Side side note: contact us at Imperial Systems to talk about a factory dust control system, and don’t shop vac your daughter’s boyfriend, as we will not be held liable for what happens if you do.)
(Side side side note: We do want to see a video of it on YouTube though)
What NFPA 68 Says About Explosion Venting for Dust Collectors
Once that boyfriend is in the door and sprawled in your living room eating your last blueberry muffin, you’re going to have a hard time getting rid of him. And once dust covers your factory, you’ll have an uphill battle trying to control it.