In today’s episode of the Dust Safety Science podcast, we’re talking to Jeramy Slaunwhite, Chief Technical Officer of Explosion Safety at Rembe. He’s been on the podcast before, and today he shares his knowledge about floor sweeps and cleaning hoses in wood processing facilities by answering questions like the following:
- What are floor sweeps?
- What are some of the practical challenges that come up?
- What are some solutions to those challenges?
- Is cleaning hoses a good practice in industry?
We will also discuss some other auxiliary equipment that Jeramy has seen and experienced in industry, and hopefully give some tips on them as well.
What are Floor Sweeps?
Jeramy explained that a floor sweep is essentially a scoop attached to a dust collection pipe that captures floor sweepings. Workers take a broom, direct the material over to the floor sweep, and it sucks it up. NFPA 664, the standard for combustible dust in woodworking and wood processing facilities, has a definition of a floor sweep: which is a suction hood located on the floor with an opening to allow floor sweepings to enter the dust collection system.
Combustible dust accumulations build layers inside the facility, creating the risk of catastrophic secondary explosions that do so much damage and cause injuries and fatalities. Anything that can aid cleanup can be viewed as a good thing.
“[A floor sweep is] just a cleaning facilitation,” Jeramy says. “By human nature, we’re always looking for an easy way to do things. In a way, this evolved as an easy way to turn a dust collection system into an extension or facilitated cleaning type of vacuum, I think.”
What Kind of Challenges Come Up?
Jeramy emphasized the importance of never assuming that a floor sweep simply sucks up all debris and everything goes away.
“ When you sweep a floor, especially in a woodworking shop or industrial facility, the stuff on the floor is not necessarily all dust. There are often bits and pieces: they could be staples, screws, nails, anything and everything that could get on the floor. And it’s on the floor where the heavy stuff goes, keeping in mind. It gets swept over into this little suction scoop and sucked up and taken away if it’s not super heavy. Those metal particles and bits and foreign objects can impact and scrape on the insides of ducting and filters, and serve as an ignition source in the dust collection unit for a fire or explosion. That’s where the real hazard exists.”
Dust collection systems are designed to capture fugitive dust where it is created, and then suck it away to a system that is properly designed and protected.
But when dust is on the floor, it’s either from other operations or fugitive dust that escapes the dust collection system. There could be problems with large foreign material in addition to sparks: a large piece of wood could cause filter damage or staples and nails could tear the filter media, resulting in dust blowing into clean air.
Large material chunks – nuts, bolts, rocks – might not necessarily make their way through the entire system. They might get kind of tossed around or inevitably lead to some sort of plugging. Heavy quantities of dust could overload airflow capacity, leading to plugging and system deterioration issues.
What Are Some Solutions to Those Challenges?
NFPA 664 states that when designing the airflow of a dust collection system, you don’t necessarily have to take into account the air capacity used for floor sweeps because they’re normally closed with a flap. They are typically used during an offline operation or intermittently.
“But with that being said, I’ve seen far too many that are just permanently open,” Jeramy says. “And with dust collection systems, especially the smaller ones, they are often under designer capacity anyway. So every little bit of air robbed from where the dust is being generated is just going to lead to more cleaning and more mess. So they’re used as an inherent pneumatic dustpan, which would be better off cleaning up and picking up manually. But of course, it’s just easy to sweep it into the floor sweep. They become sort of a bit of a Band-Aid for inadequate dust containment capture inherently.”
He emphasized that a dust collection system takes up dust, which is different from floor debris. The latter doesn’t belong in a dust collection system.
“Most people treat the dust collection system as a large vacuum. But NFPA highlights that central vacuum systems create a significant specialized hazard in themselves because of the range of debris that they are expected to collect and suck up. Central vacuums should be central vacuums, and they’re typically designed at a lower flow but higher pressure, and able to overcome high volumes of material that can get sucked back to the filter unit. So again, if the system is not properly designed as a vacuum system, it probably shouldn’t be used as one. Even though it could be viewed as doing the same thing, the ultimate consideration is that you’re inducing a possible hazard. So those systems should absolutely be protected in every way because the probability factor of an explosion incident is certainly elevated by just shoving random material into the system. Whereas if it’s a closed process, it’s a lot more controlled.”
When used properly, floor sweeps can be an effective tool to assist with cleanup, providing that foreign material is managed so that ignition sources are not introduced.
Is Cleaning Hoses a Good Practice in Industry?
The dust collection system is designed as a high flow, low pressure system for dust extraction, not for bulk loading of material that would typically be sucked up by vacuum hoses. Putting a flex hose or vacuum hose on a dust collection system will likely cause it to plug because the pressure loss through that hose is immense and most dust collection systems can’t handle it. It is going to fill up, plug and be effectively useless. Jeramy said that because a dust collection system collects so much dust, it needs to be cleaning periodically with a central vacuum.
Conclusion
Floor sweeps and cleaning hoses are measures that can improve dust collector performance and increase safety in a wide range of industries, not just wood processing. The key is to use them correctly. Once their capabilities are understood and properly utilized, their contribution to a safer workplace is much greater.
If you would like to discuss further, leave your thoughts in the comments section below. You can also reach Jeramy Slaunwhite directly:
Email: [email protected]
LinkedIn: https://www.linkedin.com/in/jeramy-slaunwhite-04b30019/
Website: https://www.rembe.com/
If you have questions about the contents of this or any other podcast episode, you can go to our ‘Questions from the Community’ page and submit a text message or video recording. We will then bring someone on to answer these questions in a future episode.
Resources mentioned
Dust Safety Science
Combustible Dust Incident Database
Dust Safety Science Podcast
Questions from the Community
Dust Safety Academy
Dust Safety Professionals
Dust Safety Share
Organizations
NFPA
Standards
NFPA 664
Companies
Rembe
Thanks for Listening!
To share your thoughts:
- Leave a note in the comment section below
- Ask a question to be answered on the show
- Share this episode on LinkedIn, Twitter or Facebook
To help out the show:
- Subscribe to the podcast on iTunes
- Leave a review and rate our show in iTunes to help the podcast reach more people
