In this episode of the DustSafetyScience Podcast, we talk to Kevin Jeffries, senior process safety specialist at Dekra Process Safety in Baltimore, Maryland, about process startup and shutdown.
There are a lot of facilities that have shut down due to the COVID-19 pandemic. Others are short-staffed due to social distancing requirements. With so many shutdowns in place, it’s critical that everyone understand the procedures for safely bringing equipment back online.
Kevin is a certified fire protection specialist with over 20 years’ experience in environmental health and safety. In addition to having worked for companies like Fujifilm and Kellogg, he was part of the team that helped Imperial Sugar to rebuild after the massive 2008 explosion.
“I’ve had experience with the proactive prevention side of combustible dust fire and risk mitigation and, unfortunately, been part of working through the aftermath of significant events: everything from re-establishing culture to rebuilding systems and installing new equipment,” he said.
In this interview, he answers the following questions:
- Have you noticed more fires and explosions during shutdown and startup operations?
- What other things might be happening during start up and shutdown?
- What steps should be taken when starting a system up again?
Have you noticed more fires and explosions during shutdown and startup operations?
Kevin acknowledged that he has seen things that did not result in a large-scale fire or explosion event, but “the pieces to the puzzle were there.”
He explained that there have been times when a system handling organic material like sugar has sat idle for awhile. It may even have gone through a preliminary washdown, but the material inside has been sitting and fermenting, creating added pressure in the vessel. When the system starts up, conditions are ripe for a significant event.
“I haven’t seen a direct flash fire or explosion, but I have seen instances where the bags and bag houses have ruptured upon start-up, where all of the pieces of the dust explosion pentagon are there at different times, but they don’t all come together to create the event.”
He warned that a processing plant is not like a car that can be left for a couple of days or even a couple of weeks and then suddenly start back up.
“You’ve got to make sure that you’ve got the right conveying velocities, make sure the lines were purged prior to the shutdown, even though in most cases, like with what’s going on with COVID-19, people aren’t doing emergency shutdowns,” Kevin explained. “But they need to make sure it’s still an orderly shutdown and you don’t have materials stuck in lines that could potentially settle out or create issues long term.”
What other things might be happening during startup and shutdown?
Kevin said that when operations aren’t running at full capacity and a mechanical failure occurs with one of the lines, parts are sometimes ‘robbed’ from inactive lines to maintain the ones being used. If the system is started up without a full safety check or inspection being carried out first, critical control or safety functions could be missing.
Planned maintenance is another issue. When a facility is down to a skeleton crew, planned maintenance may not get done. If a piece of equipment has been started up without making sure that the lines were purged before shutdown or that bonding and grounding is in effect, the result could be disastrous.
“When you make that decision to shut a line down, the first thing you should do is look at what other systems are connected to the process you’re shutting down,” he said. “If you have a dust collector and you’re shutting down process A, but process B also runs off the dust collector, it has to run in order for Process B to continue to run. It seems simple, but sometimes folks don’t think about those interconnected upstream and downstream processes when they make the shutdown.”
He also recommended:
- A thorough cleaning of all machines scheduled for shutdown as well as the surrounding area.
- The implementation of a barricade and control system to prevent unnecessary access to the area.
- Confirming that equipment won’t default to a factory set program after being shut down for an extended period of time. If it does, critical operating and safety data can be lost.
“This happened with one company I worked with,” he recalled, referring to the last point. “We took a piece of equipment down, killed all power to it. It sat for more than eight hours. We learned that it had enough of a backup to retain programming, but once it got beyond eight hours, it basically defaulted to a factory setting. When you start it back up, critical safeties are bypassed and things like that. You want to validate any of those recipes and programs prior to starting up just to make sure that everything is there there in terms of critical safety.”
What steps should be taken when starting a system up again?
Kevin recommended that startup be preceded by confirmation that everything is still properly secured, bolted in place, and in good working order. There are no components missing and all protection systems, such as sprinklers or chemical suppression bottles, are in place and functional.
“I generally advise the continuity check at this point in time too,” he said. “You want to make sure that all of your bonding and grounding is not just physically there, but still functional. You’re going to make sure that all the critical systems and safety systems are working. Do a dry run and make sure that, again, all your e-stops and interlocks are working and that you’ve got the right phase velocities on dust collection. Make sure that you’ve got all the conveying velocities in your ductwork. Make sure that your fans are fully functional.”
If there are any new employees in the facility, Kevin recommended having a focused orientation.
“You don’t want to just assume that they’re going to be able to jump back in and start up. They are still new. They haven’t had enough time to work out the bugs and learn all the processes as they should.”
Conclusion
When asked if he had any advice for the podcast listeners in general and DustSafetyScience in particular, Kevin responded, “Everybody just keep fighting a good fight. You’re doing a great job. I’ve really enjoyed all the information that you’re putting out. You’re making it definitely something that’s piquing everyone’s awareness. And I think (as) we get more people on board. We can start to see more proactive preventative steps. So, again, kudos to you and all the efforts.”
If you would like to discuss further, leave your thoughts in the comments section below. You can also reach Kevin Jeffries directly:
Tel: 1-609-285-9244
Email: [email protected]
LinkedIn: https://www.linkedin.com/in/kevinnjeffries/
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
DustSafetyScience
Combustible Dust Incident Database
DustSafetyScience Podcast
Questions from the Community
2020 Digital Dust Safety Conference
Companies
Dekra
Previous Podcasts
DSS078: Case Study - Grain Dust Explosion in a Milling Facility with Dr. Suzanne Smyth
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