Fire Science Show

237 - Fire Fundamentals pt. 18 - Explosions with Ali Rangwala and Lorenz Boeck

• Wojciech Węgrzyński

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Welcome back to Fire Fundamentals! Today with prof. Ali Rangwala from WPI and dr Lorenz Boeck from Rembe and WPI we take the world of explosion protection engineering. 

In this episode we touch:

• distinguishing fires and explosions by time scale and damage mode
• taxonomy of explosions by energy density and deposition time
• hybrid mixtures in coal mines and turbulent burning velocity
• severity metrics for gases and dust deflagration index for reactivity
• explosion sphere testing, ignition positioning, and model limits
• ignition sensitivity minimum ignition energy and hot surface risks
• prevention via ventilation, inerting, and ignition control
• protection through deflagration vents, isolation, and external hazards
• pressure vessel bursts, inspections, and rupture disks
• transport scenarios vapor clouds and BLEVEs with fireball correlations

We also delve into future directions for explosion research:

• emerging risks hydrogen, BESS, ammonia, and layered defenses
• space and microgravity impacts on dust and flammability

Check out the XPE programme at WPI, and find more informations on how to enroll at:  https://www.wpi.edu/academics/study/master-science-explosion-protection-engineering

I have also received some good listening material, that you could follow up with:

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Setting The Stage: Why Explosions

Wojciech

Hello everybody. Welcome to the Fire Science Show. And here we are once again back, uh, to the Fire Fundamentals Series, or perhaps today it's explosion fundamentals. But on that in a second, fire Fundamentals is one of the audience favorite. And serves a role to introduce some aspects of fire safety engineering, perhaps in a little bit more structured way than the general podcast interviews, but still serve the same purpose, transferring knowledge in an easy way so we all learn from it. I also learn, uh, from doing those episodes, I learned a lot from doing those episodes anyway. Uh, for this episode, I thought we have never really covered explosions. Well in the fire science show, well, it's a fire science show, not the explosion, show. But, uh, I guess, uh, whether we like it or not, fire safety engineers are commonly exposed to some sort of explosion engineering in one way or another. At least I have been over the years of my career, continuously asked about some explosion related Analysis, commentary or consultations. Therefore, I think it's important to at least have the basics covered and to teach explosions. I, I went to people who teach explosions every day, and they actually have opened a whole master course on explosion, protection, engineering. Which is, I believe the first one around there, those great people? Are Professor Ali Rangwala and, uh, Lorenz Boeck. Ali is a professor at Worcester Polytechnic Institute, WPI and, uh. Lorenz is a chief uh, officer at the Rembe and also an adjunct professor at the WPI. And as I said, they teach a whole master course and explosion. I ask them to do a very difficult thing to give me a 1 0 1 version that com. Pressed version of stuff that they try to convey through the course. In one podcast episode, we also talk a lot about why it's important to learn about explosions. When that knowledge becomes important and useful, how it is used, what types of explosions are there, what are the severity measures, what are the sensitivity measures, All that in this compressed podcast episode. I hope you enjoy. I've learned a lot and I hope that you will as well. Let's spin intro and jump into the episode. The Fire Science Show podcast is brought to you in partnership with OFR Consultants. OFR is the UK's leading independent multi-award winning fire engineering consultancy with a reputation for delivering innovative safety driven solutions. we've been on this journey together for three years so far, and here it begins the fourth year of collaboration between the Fire Science Show and the OFR. So far, we've brought you more than 150 episodes, Which translate into nearly 150 hours of educational content available, free, accessible, all over the planet without any paywalls advertisement or hidden agendas. This makes me very proud and I am super thankful to OFR for this long lasting partnership. I'm extremely happy that we've just started the year four, and I hope there will be many years after that to come So big thanks, OFR for your support to the Fire Science show and the support to the fire safety community at large that we can deliver together. And for you, the listener, if you would like to learn more or perhaps even become a part of OR, they always have opportunities awaiting. Check their website@orconsultants.com And now let's head back to the episode. Hello everybody. I am joined today by Ali Rangwala, professor at Worcester Protecting Institute, WPI. Hey Ali

Ali Rangwala

Hello.

Wojciech

and Lorenz Boeck, chief, uh, scientific officer at Reba, and also an adjunct professor at WPI. Hey Lorenz, welcome back.

Lorenz Boeck

Hey, thank you.

Wojciech

Thank, thank you. Thank you for agreeing to this. Uh, we've previously tease that we need to do a explosion fundamental episode, and here we are. so before we start, maybe you guys would like to introduce, yourself and what you're doing. Where are you from,

Ali Rangwala

so yes, so thank you once again. Uh, uh, so my undergraduate degree is in, uh, electrical engineering from Pune, India, and then I got my master's in Fire Production Engineering from University of Maryland College Park,

Wojciech

Hmm.

Ali Rangwala

worked on a problem of low ventilation compartment fires, with Professor Jim Quinter. Uh, then I got my PhD, at uc, San Diego, with Professor Steve Buckley, where I worked on flame spread on condensed fuels. so then I interviewed at WPI in 2006. and, uh, they liked me here and I, and I got a job as an assistant professor. so I've been here since then. along the way, I have graduated around 10, PhD students, uh, and around 10, around 20 master's thesis students, uh, working on different problems, mostly related to industrial fire and explosion safety. from an explosion research perspective, I've been working on dust explosion problems since 2006. uh, initially I was working on dust layer ignition with Tim Myers and Alfonso Berita from Exponent. what really got me into the problem of explosion of dust explosions especially was this five year research grant, from NSF on the topic of understanding dust explosions. So at WPI, uh, one of my PhD students, Scott Rockwell, uh, he developed a very unique experimental platform to measure laminar and tur and burning velocity of air and hybrid dust, air gas mixtures. And so this was a shift from the traditional explosion sphere apprentice. we later worked, on, experiments and modeling with Professor Sava Ackerman from the University of West Virginia, on dust explosions, especially in coal mines. I've also written a book on explosion dynamics, with Bob Zalo. And Bob was at WPI, uh, when I joined. And a lot of courses I teach were originally, were originally developed by him. we are currently working on building Bob's legacy at WPI by working towards creating one of the best curriculums related to the study of explosion safety in the world. And last year we launched a Nation's first Masters of Science Explosion program, in explosion production engineering.

Wojciech

That, that's good. That's good. Well, I, I knew who I'm bringing to the show. You're definitely the explosion, person in my mind. Uh, how about you, Lawrence? What, what brought you to Explosion? What's your background?

Lorenz Boeck

So I started in explosions during my PhD, which was a technical University of Munich, and I'm very thankful that my advisor, professor Meyer, brought me into this world. He offered me a research topic on the explosions in Fukushima. So nuclear reactors scenario where hydrogen release due to a loss of coolant led to hydrogen explosions. that started the journey for me. So ever since my PhD, I've been doing explosion research and then transitioned into industry. After PhD, I came to the us I worked at Caltech with Professor Shepherd, especially on explosion hazards in commercial aviation. Then I made the switch to industry. I joined fm, or at the time they were so called FM Global as a research scientist, where I was in charge of large scale explosion testing, as well as modeling and testing of explosion safety devices. After if I'm a joined Reba as Chief Scientific Officer, where I'm now in charge of our r and d efforts to push the boundaries of explosion protection. since last year, I'm lucky to involved in the explosion Master's program at WPI. Very thankful for that. It's a fantastic experience to be able to share, experience and our understanding from an industrial explosion protection standpoint with the next generation of engineers.

Wojciech

Uh, you have started an Explosion protection engineer program, uh, at WPI. It's a fresh initiative. Perhaps you tell me why, why do you think this, field, needed a whole program related to it?

Ali Rangwala

so, uh, WPI has always been in the forefront o of teaching, developing and cutting edge research on, uh, engineering safety. Uh, we have a fire protection engineering program that is, uh, almost 45 years old and we have been teaching graduate level explosion protection related courses since 1980. Uh, when Professor Bob Zalo, after having a successful career at FM Global, decided to join WPI he developed some of the first courses, in this area. so in a way he was a pioneer in defining the explosion, production, engineering discipline. so, uh, why have we started, uh, this program? Um, the reason is the world is moving towards a direction of carbon neutral energy.

Wojciech

hmm.

Ali Rangwala

so this means renewables, hydrogen biofuels, and any kind of storage of energy, uh, for example, in batteries as well. Um, all this is going towards a high energy density, storage solution. high energy density, storage, transport and handling. uh, and the fundamental problem with any of these solutions, is explosions. So as you start storing more and more amount of energy in lesser and lesser amount of volume, the hazard due to an explosion is much greater so keeping this changing, global environment, uh, the faculty at WPI from chemical engineering, civil engineering, mechanical engineering, uh, aerospace engineering. Fire production engineering, they all came together, uh, and decided to roll out this, uh, interdisciplinary explosion production engineering program. uh, it's the first program which is a master's program, in the us. and the idea was to bridge the knowledge across many engineering disciplines, uh, towards defining a curriculum for explosion protection engineering. Uh, so we have been internally working on this, for almost two years. Lawrence has been a part of this as well in kind of defining the curriculum, how it should look from an industry perspective, and, and I think we have some of the most unique and interesting courses, uh, in this subject area. and, the thing that you must remember is the practice of explosion. Production has existed for a very long time, but it basically lies in this, in these codes and standards, on one side and then on technical papers, on the other side.

Wojciech

Mm

Ali Rangwala

makes it very fragmented, and this was an attempt to truly define this discipline for the first time. and also importantly, the, program is dedicated to, uh, Bob Zilo.

Fire Vs Explosion: Core Differences

Wojciech

Fantastic. And how do you think, how big is the overlap between the explosion prevention versus, uh, fire protection engineering? Does the overlap exist? Is it how, how much of it is, is common between the disciplines and how much divides them?

Ali Rangwala

well, there is a, uh, there is a big, uh, difference, uh, between fire, and explosion to start off with. so, your key distinction, between an explosion and a fire, uh, is the timescale and physics. So fires evolve over minutes, while explosions occur over a millisecond. secondly, fire is fundamentally about thermal damage. and explosion, are more about pressure, damage, uh, and damage from the fragments, uh, that are created from the pressure damage. so naturally you have some overlap of where, for example, core courses like combustion, fluid dynamics, ignition. in, are, are in sync, uh, but then you have to kind of have a completely different, uh, ideology. when it comes to explosion protection, engineering, where you have to go into the compressible flow world, have to go into explosion dynamics, which is very much different from, fire dynamics, explosion protection, engineering, again, because of the timescales, uh, in the problem, which are extremely small. and the fact that you are trying to study about pressure, uh, rise versus time compared to temperature rise versus time, uh, you have a, a different, course or a different, a different set of graduate courses towards that. Uh, and then finally you have your modeling as well. So explosion modeling and fire modeling are, are two different, altogether.

Wojciech

But, uh, I, I guess, uh, some things must be very common. I think flammability lies in the heart of both disciplines, and I think to a large extent, there will, at least from the fire protection engineer perspective, there will be an overlap in assessing the hazards, you know, the fuels, uh, the potential scenarios, even trees. I, I think this is where a lot of, uh, fire protection engineers will have to deal because something can end with fire, can end with explosion in, in many cases.

Lorenz Boeck

Yes. I think it's interesting also from a perspective of, you know, the folks, the students who are joining this program, quite a few of them come from the fire protection

Wojciech

Okay.

Lorenz Boeck

And, um, that's where this overlap, I think creates a great experience for the students. start to understand how these technical, uh, challenges, but the technical, also the technical knowledge they already bring from fire protection helps them understand concepts and explosion protection. It's just a different. Perspective and a different twist on similar physics. Like Ali said, you know, combustion physics, combustion science forms the foundation of all of this. But in explosions, we add on compressible flow, blast effects, structural response under dynamic conditions and so on. So especially if you go through both fields in your educational journey, fire protection and explosion protection, I think you can get a very comprehensive package that gets you ready for the safety industry and many problems out there. I have a student in my class right now, he wants to go in the oil and gas field. So guess what? Both are extremely relevant.

Types Of Explosions And Scales

Wojciech

And, also touching on our previous episode a few weeks ago on battery storage systems. I like, this is so fundamentally intertwined. The, the fire safety and explosion safety for those facilities requiring a holistic management. I think there's a big future. So congratulations on setting up this important program. And thanks, once again for coming to Fire Science Show because we have, you know, fire Protection engineers here. Let's hope they also have a nice entrance to explosion through this, uh, talk. perhaps we should clear out the types of explosions first because, uh, you know, explosion is, I, I guess a broad term that, uh, you can throw a lot of things into it. So how you, as, as experts in this field, how do you, I don't know, subdivide the, the, the world of explosion. What, what, what are your brackets that you divide the explosions into?

Ali Rangwala

Okay, so in terms of definition, let's start there. So, as I said, an explosion is a rapid release of energy, that generates a pressure wave, that is, uh, traveling away from the source. And, uh, a fire, uh, on the other hand is, can also release huge amounts of energy, but this energy is released relatively slowly, and you don't get that same kind of, blast type, pressure wave. so with that in mind, the, the way explosions are classified are usually based on these two, ideas that what is the quantity of energy, that is, uh, per unit volume, and what is the timescale. At which that energy, is deposited per unit volume. so these are the, two scales that you kind of now start classifying explosions, on. to give you an example, the highest amount of energy per unit volume, or, or the highest pressure comes from a nuclear, explosion. you have enormous amounts of energy that are deposited, around 10 to power of five. over pressure in a very, very small timescale of around one microsecond. in one microsecond, you are having an over pressure that's about 10 to four of five bars, So that, that forms like the, the strongest kinds of explosions. and then you can now start, uh, visualizing all the different kinds of explosions that take place, based on this idea, the simple idea of what is the over pressure that is created or what is the energy that is deposited per unit volume. If you see energy per unit, volume has the same, is is the same as pressure. Pressure is nothing but energy per unit volume. And so what is that, that pressure and how long? Time does it take for that pressure to be reached. So then you can go on to explosives, where you are one order of order magnitude less compared to nuclear explosion. So when you have, when you think of an explosive, you are looking at around 10 to bar of four, bar over pressure, and the timescale is about 0.1 millisecond. not the microsecond timescale like the in nuclear explosion, but 0.1 milliseconds.

Lorenz Boeck

And I think, um, Ali, under explosives, it's actually interesting. There are engineered explosives, so materials that are designed to explode that are used for blasting, for example. But then there are also materials that are not really designed with the intention of an explosion, but that can explode with very similar physics. For example, fertilizer grade ammonium.

Wojciech

Hmm.

Lorenz Boeck

leads us to accidents. For example, the one in Beirut, right? Where that material can get sensitized and explode in a manner, very similar to actual engineered explosives.

Ali Rangwala

Yeah, exactly. so then, moving along on that same, idea, the next order of magnitude less, which is around 10 to four of three bars of over pressure, and slightly longer timescales that are about 10 to hundred, microseconds. you are looking at pressure vessel bursts. So these are explosions that necessarily don't even involve combustion, are just pressurized vessels that can break open and release over pressure in the form a blast wave. then, uh, again, look along the same, if you go again further down 10, around a hundred bars of lower pressure. These are typically steam explosions, so these. Over timescales of around one millisecond.

Wojciech

I.

Ali Rangwala

further down, from a hundred bars to 10 bars of over pressure, and now you're looking into closed vessel deflations. so these are your, your classic explosions or, or deflations that take place when you have complete confinement. So let's

Wojciech

Hmm.

Ali Rangwala

I'm having a, propane air or methane air mixture in a, in an enclosure and it's completely sealed. Uh, and if I ignite it, uh, I will get over pressures about 10 bars, uh, with timescales between one 200 milliseconds. So these closed vessel deflagration also form the standard for explosion safety, which is your classic 20 liter explosion or the one meter cube explosion vessel that's used in industry for all the flammability assessment associated with gases, with mist, with, with dusts. And so on.

Lorenz Boeck

And Ali in explosion protection engineering. this is an extremely important category because this is where we protect, for example, industrial equipment using things like deflagration bands so that these closed volumes, uh, don't rupture. For example, under the internal over pressure of an explosion.

Ali Rangwala

yeah, so that's, so in terms of engineering contacts, these are like your standard equipment, deflations, explosions and dust collectors, explosions and electrolyzers. so now from the closed vessel deflations, uh, which are 10 bars, we can go further down the scale. So now we are looking at over pressures that are of the order of one bar or even less. so these are your classic, uh, building deflations. Uh, and these are the most common explosions. Like you have gas leaks in buildings, uh, you have dust explosions. and these are usually with over pressures between 0.1 to 0.5 bars, uh, with timescales of the order of 0.1 to one second. So we have gone from that, that microsecond in nuclear explosions, then the

Wojciech

Hmm.

Ali Rangwala

in, uh, in these, uh, steam explosions and closed vessel, explosions to these building deflations that now start taking place in 0.1, second to one second. So these are slower and they are weaker in terms of the energy wise, uh, the energy deposition. But however, these are equally devastating. I mean, you can see this in in practice as well. When you have an explosion, you have a very high amount of damage. and the reason is because you don't need much in terms of a pressure load. To to break open walls of an enclosure. So typically walls in a building will start opening up or breaking at around 0.1 bar over pressure. that also comes to why explosions are so dangerous because, you don't need much, to, uh, create, damage.

Wojciech

is the type of expl ties to the fuel to the circumstances? Can the same fuel be both, something that def flow rates and detonates, for example, or, or the type of dictates the, the type of hazard explosion that that can occur? Or, or, or there are any other factors into that?

Lorenz Boeck

Well, there's an impact of scale, first of

Wojciech

Okay.

Lorenz Boeck

right? Some of these categories that just different, differ massively in scale. If you go, um, from a small enclosure all the way up to maybe a Vapor Cloud explosion, that is one of the largest events we see as far as

Wojciech

Hmm.

Lorenz Boeck

extent of, of Vapor Cloud, for example. So it takes a certain time to consume the fuel. That's the scale aspect. The other part is like you're saying, the rate of reaction, and you already mentioned Deflations and Detonations, so I think we can get into that in a little more detail. But Deflations burn a lot slower than Detonations, the two distinct categories of explosions and some fuels can undergo either deflagration or detonation, for example, flammable. Gas mixtures with air or with oxygen especially, that can be very reactive. So depending on what combustion phenomenon you have, I agree with you. Yeah, your timescales can be very different.

Wojciech

in Poland, a big thing was always the, uh, coal mine explosions where you would have methane and, and some kind of dusts. Uh, and, and from what we've learned in here is local knowledge that, that we are exposed to. Those were very challenging to, to manage because they were in some way very powerful. Can you, can you also comment on, on those types of mixtures.

Ali Rangwala

Yeah, so those are your classic, uh, hybrid explosions, where you have both particles as well as, uh, a gas, and in coal. Mine is usually methane. Uh, so you have methane gas and, and these tiny particles of coal and they both are interacting. and, uh, from a fundamental point of view, it's a very, complex problem, uh, because you have particle air interaction, you have, the actual premixed flame as well that, that exists. And in that premixed flame, you now have these coal particles. and then when you add turbulence, which is what most of these explosions are, they're highly turbulent. You have additional effects. So you have mixing effects that are created because of the presence of the particles as well. the quantity that you usually use to, to quantify or model these explosions, uh, is your turbulent burning velocity. and that, and, uh, we have done experiments at WPI, uh, that show that your, turbulent burning velocity, can increase or decrease, uh, depending on the particle size, depending on the particle, concentration, and, and depending on the level of turbulence.

Wojciech

what is the burning velocity exactly? Like w what, what kind of o of thing does it measure?

Ali Rangwala

So the simplest way to imagine the burning velocity is, let's start with a laminar. Context first. So imagine you have a premixed flame that's moving, and now imagine that, uh, you are on this flame and what do you see? You see this unburned gas that's approaching you. So the velocity at which this unburned gas is approaching you is the burning velocity. and then now again, you are, you, you are having this, this flame moving. And Lawrence is, for example, watching me while I'm on this pre flame. So the velocity at which I am moving is the flame speed. So those are the two main aspects. when it comes to, velocity, uh, when it, uh, with premixed, uh, combustion.

Burning Velocity And Flame Speed

Lorenz Boeck

like Ali was saying, um, often we use the fundamental laminar burning velocity as the quantity to characterize reactivity of a flammable gas mixture or vapor, for example. but then in reality that burning velocity gets modified through different effects that can lead to flame acceleration.

Wojciech

Hmm.

Lorenz Boeck

For example, flame instabilities, in the absence of turbulence, flame, uh, flames can be unstable, create flame surface area and therefore accelerate. then especially when turbulence comes into play, so when the flow that is generated by the explosion itself, for example, interacts with the confinement, so the walls of your coal mine, for example, or any obstacles that can generate turbulence that can strongly accelerate combustion, and going back to the types of explosions that would now lead you to a faster energy release. And therefore how we would see it, a more violent explosion that is also harder to mitigate.

Wojciech

So, so there is like a direct link between how fast it occurs and uh, how severe the outcome in terms of pressure wave is. What, what's the link there between, between the timescale and damage?

Lorenz Boeck

So for example, if you use a closed vessel explosion as an example, so you

Wojciech

Hmm.

Lorenz Boeck

say, a piece of equipment. There are two main questions. The first one is how much pressure would be built inside of the equipment if there's a deflagration. Let's say the enclosure remains intact, how much pressure would you build? And then the question is, does that pressure exceed the strength of the enclosure? That's one measure of severity, right? Simply comparing that maximum pressure against the strength of the enclosure. if you use methods, for example, like deflagration venting, so you put openings in your, in your vessel that are initially covered with a lightweight membrane or a lightweight panel that are intended to blow open and relieve pressure, then the speed of the pressure rise comes into play. the faster you build pressure inside of the vessel due to the explosion, the more vent area you need, for example. So this becomes a very dynamic effect where, again, the faster you burn, the faster you generate volume, the faster you have to also be able to relieve that volume from the enclosure to protect the enclosure. So both matter of pressure and the speed.

Wojciech

in practical engineering, you know that through some fundamental relationships, I know first principles or, or this is something, uh, validated experimentally for, uh, types of mixtures.

Ali Rangwala

Um, so,

Wojciech

I,

Ali Rangwala

what Lawrence was talking is actually a very important aspect of explosion, and specifically explosion dynamics.

Wojciech

Hmm,

Severity Measures And Dust Indices

Ali Rangwala

uh, the, so just like in fire dynamics, uh, fire dynamics evolved based on the need to model growth of a fire in a compartment. We have these one zone models, two zone models, et cetera. And the entire physics of fire growth, which coupled with a smoke layer, your, um, smoke layer growth, your doorway flows, temperature rise in enclosure. These are all developed using these very elegant models that were developed by Thomas, by and many others. um, in the world of explosions, uh, there's no universal model yet that kind of captures this growth of an explosion in an enclosure. And this again brings us back to why it's so important a discipline, towards explosion protection because, in explosions we are interested heavily on what is this pressure versus time as your premixed flame propagates in an enclosure, as that enclosure starts venting, and you now have hot exiting the enclosure, not at slow rates like you would see in a fire, but at very high speeds, you're looking at 200 meters per second of venting, uh, flows. so this is, uh, so that is something that forms this also the starting point, like, uh, even a zero dimension enclosure model can model the pressure rise in an enclosure as a function of time. And this was something that, Like, for example, Bob used to spend a lot of time, in teaching, uh, as well. Lawrence spends a lot of time in teaching this in his course on explosion collection engineering. I spent a lot of time teaching about this, uh, in explosion dynamics.

Wojciech

And, and do we have like experiments or tests or standards that allow you to, to capture some of those characteristics that, you know, in, in, in, in, in fire protection engineering, you'd have the con calori matter, you'd have all the reaction to fire experiments. Uh uh. Ignition related experiments, et cetera. What do you use to to, to build knowledge on those, on those phenomena?

Lorenz Boeck

Yes, I like the link with the cold colorimeter because that really is the workhorse of fire protection.

Wojciech

Yeah.

Lorenz Boeck

in, um, explosion protection. We have a workhorse too. That's the explosion sphere. think of an explosion sphere as a very, very simple test. It's simply a closed volume.

Wojciech

Mm-hmm.

Lorenz Boeck

Sometimes there's spherical, sometimes they're actually cylindrical vessels. But you have a, a, a sort of closed vessel that you can fill with a mixture of interest, and then you can ignite that mixture typically at the center. And you can observe, especially the pressurize as a function of time. a quantity that can inform, for example, the rate of pressure rise that can then be scaled to account for volume scaling effects, for example. So how would that behave at a larger scale like an at an industrial scale, for example? we can also use that test for many other safety characteristics. Learning about safety characteristics of mixtures. For example, test for minimum ignition energies, or a test for limiting oxygen concentrations. Or a test for, like I mentioned earlier, maximum explosion pressure. These are all relevant safety characteristics that are typically determined by test according to standards such as A STM standards.

Wojciech

I really want to follow on characteristics or ignition, but I, I need to ask immediately one question. You said, uh, it's sometimes ignited at the center, how much the location plays a role and the follow up, immediate follow up to that question is how much the complexity of the space influence the explosion outcomes. Because I can imagine if you have an explosion in a large, I don't know, grain silo, which is like a round vessel, that's it, it's probably different than you have, explosion in a, I dunno, shopping mall filled with a lot of, shelves, et cetera. So, so how, how much the location of ignition and, and, uh, the, the, the type of enclosure in which you have the explosion, uh, plays a role in, in all of this.

Testing Tools: Explosion Spheres

Lorenz Boeck

That's a great question. And that really goes into the link between these simple lab type experiments and then the reality, right? The types of explosions we see in, in residences or in industrial facilities. And of course we have much more complex geometries. In reality, we are not looking at spherical vessels. In reality, typically that experience explosions. one fact is also that we typically don't know the ignition location, or very often we don't know potential ignition locations. So in explosion protection engineering, we often have to understand worst case scenarios. we consider. For a certain structure. For example, there might be ignition taking place in different locations. There's a certain probability attached to every one of these ignition locations, but in general, there's maybe a host of ignition sources in a certain space. In our job, we need to understand what of these or which of these ignition location constitutes a worst case explosion scenario. So what leads to, for example, fastest rate of flame propagation or highest amount of pressure built to that ignition location, and then design for that worst case? Because again, in reality, we are not in charge, we are not deciding where ignition will happen. It will just happen at a possible location where an ignition source is present. That could be, for example, even a, a human who is walking and who is building electrostatic charge. So you're really not in control of where that ignition would happen.

Ali Rangwala

and just coming back to that question of the, the test. So whenever you have a standard test. you are basing the standard test on some kind of a model. Uh, so for example, when you're having a cone test, you're basing it on this idea that you have this uniform heat flux that's supplied by the cone kilometer you are applying, that at, uh, and you know exactly, you're quantify that. Exactly. and then you're trying to measure time to ignition or heat release rate, or heat of combustion or whatever. your boundary conditions and your initial conditions are very well prescribed in that standard test, so that when you are extracting parameters from that standard test, those parameters are quantified repeatable. The same idea exists with the, with the explosion, sphere as well, which Lawrence had said is the workhouse of explosion, protection, engineering, or the explosion world, where the actual test needs you to have ignition at the center. The, the model that correspondingly evolves, which is the flame propagating from the center, as a spherically expanding flame and going towards the walls of the explosion sphere. Uh, that, that, that model has a mathematical basis, that is known. And then, and then based on that basis, you are now extracting parameters. So as soon as you start changing the location of ignition, even in the standard test, you are going to get a different, flame movement. you will have different effects because of buoyancy, because of the wall, and these alter the mathematical model and therefore that test is no longer going to be valid in terms of extracting parameters. It just like you are having a cone kilometer and rather than applying a uniform heat flux, you start applying a heat flux that's variable. I mean, you can do that from a research exercise, but from a. of extracting parameters for, for a standard, you don't do that. So the same idea here as well.

Wojciech

in terms of, igniting those mixtures, how do you quantify ignition and how easy it is to, to ignite, such a mixture? And what role does it play in, in, in explosion engineering?

Lorenz Boeck

So, you know, but once we're talking about ignition, we can maybe take it a step back. What we talked about so far, we talked about flame speed, we talked about

Wojciech

Hmm.

Lorenz Boeck

pressure. Those are severity, parameters of explosions, right? How bad will it be Now we're switching toward ignition. Those are things we call sensitivity parameters. How sensitive is a mixture to ignition? How easy or how hard is it to ignite? And this is also strongly linked to probability of an explosion, right? Again, now how bad will it be, but how likely might it be that an explosion occurs in a certain mixture? So it's a bit of a different perspective. equally important, right? Because we need to understand what is the likelihood there will be an explosion in a certain mixture given a certain ignition source, for example.

Wojciech

Is there any severity measure that we've missed? I would like to complete one before we jump to another.

Lorenz Boeck

I think, um, what we can point out for dust explosions, the severity parameters are defined a little bit differently by necessity, actually, because dust explosions are very complicated, the physics

Wojciech

Hmm.

Ignition Sources And Sensitivity

Lorenz Boeck

complicated, the material properties vary widely, and the application conditions vary widely. what we're doing there, we're not typically using fundamental burning velocities, but we're using the so-called deflagration index, and that is directly tied to the spherical bomb or spherical vessel experiment where we measure rate of pressurize.

Wojciech

Hmm.

Lorenz Boeck

to get a deflagration index, would measure the maximum rate of pressurized in a standardized vessel, and we would scale that with the test volume. So mathematically it's the maximum rate of pressurized, multiplied with the test volume to the power of one third. That's, so-called very important cubic law of explosion protection that scales over volume. And that allows us to define this index as a reactivity parameter of a certain dust. what's important there when you see these, defecation indices. So for example, a certain dust might have a defecation index of 200 bar meter per second. That is a quantity that gives you a relative comparison between different dusts. So you can tell, well, this dust is 100 bar meter per second, that dust is 200. So the one with 200 is more reactive. Yep, that's a fair relative comparison. But that number is not a fundamental parameter of the dust itself, and that's what differentiates this approach from the fundamental laminar burning velocity, which is a fundamental property of the mixture. the deflagration index is a function of the material, so the dust material as well as the test conditions, for example, initial turbulence, but again, by necessity, that's the parameter we're using for combustible dust to quantify reactivity.

Wojciech

Also, when you talk about explosives, there's also different metrics, right? Like TNTN, equivalent, et cetera. That that's what I've seen.

Lorenz Boeck

Absolutely. So when you have explosives, you're interested primarily in the amount of energy that gets released from a certain mass of that explosive.

Wojciech

Yeah. Okay.

Lorenz Boeck

one of the conventional ways of scaling that or making different explosives comparable is using a TT equivalent mass. So you're essentially comparing a certain mass of an arbitrary explosive with a certain mass of t and t that would release the exact same amount of energy.

Wojciech

Hmm,

Lorenz Boeck

a scaling idea. There are different variations of this, uh, less focused on energy, for example, but maybe more focused on blast impact. generally we like to tie it back to t and t because it's such a well understood and extensively researched material.

Wojciech

So, okay, let's move to, to sensitivity then. Uh, talk, talk about ignition in, in, in those mixtures, please.

Lorenz Boeck

Right. So how easy or, or hard is it to ignite a certain mixture? Um, generally, for example, when you talk about flammable gases or vapors, those are actually very easy to ignite and. How can I say that? Well, by comparing the minimum ignition energy of these mixtures with ignition energies by common ignition sources or of common ignition sources, for example, when you test these mixtures for ignition, for minimum ignition energy, you might find that hydrocarbons, for example, in air, have minimum ignition energies on the order of 0.25 millijoules. a very small amount of energy that is needed to ignite that mixture to put that into context, electrostatic energy that is accumulated when I walk, um, for

Wojciech

Hmm,

Lorenz Boeck

especi, when it's very dry out and I walk over flooring that is not, uh, dissipating, then I might accumulate maybe around 10 millijoules of energy. So that's already well above actually orders of magnitude above what I need to ignite a flammable gas or vapor mixture typically.

Wojciech

any, any open combustion. I guess that's already way, way more than enough, right?

Lorenz Boeck

So open flame. Yes, open flame is a very strong ignition source in that context that provides plenty of energy to ignite one of these mixtures. in fact, there's a whole variety of ignition sources that we need to be aware of, that we need to understand in terms of their ignition energy potential. but then also outside of sources that can, for example, provide a spark. So electrical sources, we need to consider things like thermal sources, hot surfaces, for example, right? How hot a surface need to be to ignite a certain mixture? And there's a metric for that too describes the sensitivity of a mixture that would be the minimum ignition temperature for closed vessels. For example, the auto ignition temperature.

Wojciech

And, in terms of turning this. Into protection strategies. I, I guess here the, the flammability limits play an important role do you have more tools than, than ventilation and flammability limits really in, in preventing, or,

Prevention: Ventilation, Inerting, Control

Lorenz Boeck

So you're right. Flammability limits, that's the other component of answering a question. Will a certain mixture ignite? Right? The one part is, is that mixture within the flammable range as far as is composition. So how much fuel, oxygen, and inert has, do I have, and is that mixture flammable? And the other part is, do I have an effective ignition source that has enough energy to ignite that mixture? And to prevention, you can attack any of these components that can lead to successful ignition, right? You can prevent any of these aspects individually or together. For example, you can prevent. A flammable mixture from forming. where things like ventilation come into play. So you remove fuel from an enclosure, for example, or inert. You supply an inert gas to the mixture to a place outside of the flammability zone. It's very common using nitrogen inert, for example, very common practice. you can attack the ignition aspect so you can make sure you don't have possible ignition sources in the space where you know that a flammable mixture might be present. That's called ignition source control. There are many methods around that, how you can make sure that, for example, equipment like electrical equipment cannot present a possible ignition source in practice.

Ali Rangwala

yeah. You mentioned coal mines,

Wojciech

Mm-hmm. Yes.

Ali Rangwala

mines typically use, inerts like sand, dust. or rock dust to, and they, they, they put all this rock dust on the coal mine, surface so that when, uh, when there is a disruption and the coal dust lifts up due to any kind of, disruption, and, and creates, uh, a cloud of coal dust. And that coal dust is also mixed with rock dust. And so that essentially inerts the mixture and it's, it, it's more difficult to ignite it.

Wojciech

Hmm.

Ali Rangwala

we have also done studies, in the laboratory where, where, again, you have, because it's such a complex problem where even if you have inerts like rock dust in a premixed gas mixture, what the rock dust does is it locally enhances the turbulence because. Of the, the particles. So you have that, that local enhancement of turbulence now, increases the turbulent burning velocity in some

Wojciech

Hmm.

Ali Rangwala

it's a function of the size of the rock dust. And if the concentrations are not high enough, then that rock dust essentially more dangerous because it

Wojciech

Hmm.

Ali Rangwala

it increases the levels of turbulence. And now the, the flame is able to consume a lot more, of the fuel because the, the flow of turbulence has increased.

Wojciech

I immediately know ev every, all the time we, we talk, I, I immediately jumped into fire. But you mentioned there are a lot of interesting explosions that are perhaps not fire related, like you mentioned steam explosions. You've mentioned vessel ruptures, use of explosives. Is there any, uh, thing comparable to ignition, like in, in those explosions that you can prevent? H how, how, how does an engineer deal with such hazards? What are the approaches there? 'cause obviously you don't ignite steam, but, uh, it, it's still like something must lead to a steam explosion. How does it look in, in that kind of, of, of explosions?

Ali Rangwala

so, so I'll, I'll let Lawrence answer that from industry perspective, but I'll answer it purely from an academic perspective. From an academic perspective, the way an engineer deals about with that is by education. that is why programs like explosion protection engineering are so important, because unless you don't educate. who are in the field, faced with these problems and now even newer problems because of hydrogen, because of batteries, because of, uh, all these high energy density energy solutions, it becomes, uh, very difficult, to address, uh, the safety, uh, of these.

Non-Combustion Blasts And Process Safety

Lorenz Boeck

I can take an example of a pressure vessel burst. these are actually fairly common, whether we're talking about low pressure vessels or higher pressure vessels, they happen more often than you would think. There's a great video from the CSB, the Chemical Safety Board that elaborates on these. And, um, there are different ways you can get to a condition where a pressure vessel can burst. One of them is simply that it gets over pressurized, so beyond what it is designed for. there are actually ways to, to manage that situation, right? For whatever reason, if a vessel gets over pressurized, we can provide over pressure protection. This has nothing to do with what we would call explosion protection as such, but we would see this as a part of process safety.

Wojciech

Hmm.

Lorenz Boeck

over pressure protection, for example, in the form of a rupture disc. So very simply, a device that opens at a set pressure that relieves pressure from the vessel before it conversed. um. What's interesting here also from the educational standpoint, these devices, they look very simple. They seem very simple. The functioning principle is simple, right? You over pressurize it, it opens, it relieves pressure. we need thorough engineering when we bring these devices to a certain application because we need to understand, for example, how large of an area we need to provide for pressure relief. can get quite involved actually, especially when you might have materials inside of a vessel that are reactive when during the relief you might be relieving, not just gas, but maybe a multi-phase flow. even these. Seemingly simple things like over pressure protection are uh, various engineering disciplines that need to be involved there. They, they require rigorous engineering. It's part of what we teach in the program. And um, the other part if we talk about pressure vessels, for example, is inspections. So not just engineered solutions for protection, but also inspections to make sure we understand. Is there, for example, corrosion ongoing on a vessel that might thin out the walls and weaken the walls at some point? So even though a vessel is designed for a certain over pressure, it might not be as pressure resistant once it's been in service for 10 years. We need to properly maintain, test and inspect these types of equipment.

Wojciech

as we are on technical, uh, stuff, uh, to, to prevent, can you talk more about deflagration uh, panels, the way we've touched them on the, uh, energy storage episode, but I think it's, it's highly relatable to what you've just described.

Lorenz Boeck

for sure. So what I've just described is pressure venting over pressure protection, right? So those were these scenarios that are non-reactive typically, right? You just relieve pressure. difference for explosion, venting, or defecation venting is now we're dealing with a scenario where there is combustion going on inside of an enclosure, and we need to protect that enclosure. the fact that there's combustion going on means that we can have a very rapid pressure rise. So we're not. Talking about a deep depressurization of a storage vessel, for example, from a certain pressure down to ambient. But we have a vessel whose internal pressure is actually increasing very quickly. And what that means for venting is that you need to provide typically much larger vent areas to overcome or to combat that pressurize and keep pressure as low as needed. the idea behind rupture disc for process safety and. Vent panels for explosion. Safety is similar. The implementation is different because of the hazard. Now the panels are extremely simple. They're one of the simplest method of over pressure or explosion protection. It's simply a lightweight panel applied to the enclosure that is precut around the circumference, leaving only small so-called burst tabs that are designed such that the panel opens at a set pressure. So there's a predefined pressure, a very low pressure, typically 0.1 bar, for example, at which that panel will yield, it will open and will start relieving pressure and protecting enclosure.

Wojciech

in engineering those types of, solutions, how much do you care what happens outside of that panel? You know, the propagation outside is, is, is that important? Or just getting the pressure wave out of your container? That's goal achieved, uh, time to go home.

Deflagration Venting And External Hazards

Lorenz Boeck

Uh, good point. Uh, we can absolutely not forget about what's going on outside the vent because we might actually, by doing this, by doing defecation venting, create external hazard, In the case of an explosion, we are relieving not just pressure, we're relieving a flame. We're sending a flame through these deflagration vents to the outside, we can generate external pressures. Now, the external pressures are typically by far not as high as the internal pressures might be, but still they can be damaging, they can be hazardous, can injure people can damage property. there is specific engineering methods that we also exercise when we design the fabrication vents to predict these external effects. one part of it. generally, we like to direct these vented explosions away from any hazard, away from any exposures, right? So away from people, away from driveways, for example, away from property that might ignite or that might get damaged by over pressure.

Wojciech

What about the debris that you shoot with the explosion? Is there any way you can control for that? Is that an element of the design? To minimize the collateral damage caused by, objects that that can be taken by the explosion.

Lorenz Boeck

So ideally when you protect an enclosure, for example, the goal is not to generate any fragments,

Wojciech

Hmm.

Lorenz Boeck

That's a very, very important design goal. but sometimes there are certain explosions that will generate fragments. For example, the pressure vessel burst. the typical approach is first of all to understand the hazard. So understand, for example, the types of fragments that might develop sizes, the weights then determine what velocity these fragments might have, then infer from that, how far could they reach and what impact forces or impact energy might degenerate. Attached to that is often a probabilistic analysis to understand what's the chance that a certain target gets hit by a fragment, It spread out over distance. So as you go farther away from the source, the likelihood that you actually get hit by a fragment goes down. So putting that all together gives you an informed basis for, for determining the risk that, comes with these fragments in terms of protection, when you are in a zone, for example, that is prone to fragment impact you might want to use, um, not just blast resistant construction, but also fragmentation resistant construction or fragment resistant construction protects, for example, people from potential fragments. And on an industrial site, that could be a reinforced control room, for example.

Wojciech

are things like that something that, uh, you'd expect the explosion protection engineer to know, uh, after your course? is, is it common to, to design like this, uh, outside of, I dunno, petrochemical industry?

Ali Rangwala

so an interesting thing that Lawrence did, uh, in his course, uh, which was very, well received, was he had these capstone projects for the students. And the capstone projects were basically given by industry,

Wojciech

Hm hmm.

Ali Rangwala

part of the class, the graduate course, uh, which were actual industry problems, like designer dust went uh, for a green silo or design, explosion. Went for a coal fired power plant, conveyor belt, design. An explosion went for a battery energy storage. So, so these were problems that were, that had, that had, were given by industry that, uh, were given to the students as final capstone projects for the class. And I think that was a great mechanism for the students to kind of do an actual problem that's faced by industry, apply what is being taught in the class and connected to, an industrial problem. just to give you a sense of history, uh, WPI was started with the moto of, in German, which is called Le and Kunst. And what that means is theory, and practice. So all WPI students are essentially, Trained and taught to learn in, but not just learn theory, but also to apply it. And, and, and this is, why, uh, Lawrence introduced in the form of the capstone project was like this amazing thing. Very well received. And the best part was that the, the industry was so happy with what Lawrence did, that they actually came and judged the capstone projects themselves, so that there was this, this judging panel that was created for the graduate class, which was industry people judging the, the capstones.

Lorenz Boeck

think you

Ali Rangwala

Yes.

Lorenz Boeck

just gave me a great idea for this year's capstone.

Fragments, Risk, And Protective Design

Wojciech

Well, uh, thank you. I, I hope we don't, uh, you don't torture the students too much with it, but no, I, I think, uh, such a, such a nice, chance to, to, you know, apply this in, in practice. I, I, I think it's, it's very important for people to develop a, a specific skillset. And, you know, the more I listen to you guys, the more I understand how. Specific this field is and how many things go into it because it's like at the same time, you know, the reactivity of the ingredients for explosion, but also the circumstances in which it happens, the environment in which it happens, the collateral damage that's possible and can spin off into some sort of domino effect, which you would like to prevent. You know, my personal, you know, exposure to explosions is when I design road tunnels because we designed them for all kinds of traffic. And I have to, you know, consider vapor cloud explosions, uh, you know, boiling liquid explosions. Maybe you could talk about those, uh, transportation scenario explosions. Actually, I would love to listen about them. So, and BLE perhaps?

Ali Rangwala

Yeah. So, a a levy is essentially a, pressure vessel burst in, uh, in some way. So the pressure vessel burst is you have a pressurized vessel. and, uh, what Laurens described is, uh, a fracture of that pressurized vessel that causes it to fragment because it's pressurized. a levy is just that pressurized vessel is damaged because of a fire. the structural failure of the vessel occurs because usually because of an external fire. That heats up this vessel, uh, that is pressurized and weakens it. Uh, and because of that weakening, that internal pressure causes that, that that vessel to burst. And it's fairly common in transportation because you have these road T tanks, for example, that transport, fuel liquid fuels, on, on the highways. And, uh, in some cases they have accidents. They, they collapse some of the liquid leaks. and you have a fire underneath the, the huge tanker, you have, a possibility of a ble. So, the, the main guidance with the B levy essentially is the, the time to B levy, or the time at which this tanker or the pressurized vessel. disintegrates is very important.

Wojciech

Hmm,

Ali Rangwala

Uh, and, and there are all these correlations available in literature based on empirical, data. NASA had done this huge statistical analysis, comprised of like, I think around, uh, 300 different levy accidents and had come up with a number that, you know, when you have a ble, this is the distance. Uh, you need to stand away from the site such that you don't have the blast wave or fragment fragments, uh, hitting you.

Wojciech

in open space. Also, the thermal damage from the fireball is important, right? Uh, or, or you don't care.

Ali Rangwala

Yes. So that is a big component as well. In fact, there was a very classic paper written, in the fire safety journal where there were these experiments that were done on, um, Uh, these tankers that were filled with, fuel, and there was a ble and, and the, the time it takes for the fireball to rise, uh, and then the time it takes for the fireball to stay there or linger in the air. And then the diameter of the fireball, which is how you calculate the radiative, uh, thermal damage. Uh, they were all kind of, measured. I believe the paper was by Rob Roberts, if I'm not mistaken. But there are these correlations, uh, that are again, available in, in literature about this. I mean, this is, a lot of this is also coming from the process safety engineering world, where the process safety engineers, which were predominantly chemical engineers, kind of wanted this problem really solved. so they kind of entered the fire protection engineering world and did work And then many of these researchers again, left, left, and went back to the process safety world again. Yeah.

Wojciech

Oh, well, it's, it's a good pollination of ideas by, you know, changing disciplines. I, I highly support that. And for BLEs, I, I need to check the NASA study. I hope the time to BLE is not as short as in Hollywood movies where you basic barely touch a, a truck and it explodes. I open my tunnels. We have a little bit more time until, uh, a leva. Um. One final question I wanted to ask to you guys. What are the frontiers explosion research? What, what is the current, like topics being studied? Where, where are you guys going in in your research right now?

Capstones And Industry Projects

Lorenz Boeck

Well, I can take some of the applied things that I see happening in the explosion protection industry right now. of this, as in many other disciplines, is driven by new applications, and we already touched on some of these, so new and alternative fuels or energy carriers. It's a big topic, an ongoing topic. For example, we are asked to protect more and more hydrogen systems the hydrogen economy is, is building globally. There are applications such as electrolyzers, such as fuel cells that need to be protected they present hazards that, you know, fundamentally we do understand from an explosion dynamic standpoint, from a combustion standpoint and so on. But we are definitely still in a process of developing engineering best practice to safeguard these applications. And there are very, very interesting, projects, for example, uh, electrolyzers where you can have potential of hydrogen oxygen crossover and you can generate mixtures that are very, very reactive and that could potentially detonate, right? So there goes your entire knowledge of explosion dynamics to understand. only how that scenario comes about, but then really what happens if there's an ignition in that atmosphere and what are the consequences? Um, another application, and we talked about this, is battery energy storage systems.

Wojciech

Yep.

Lorenz Boeck

one that's really pushing the explosion protection community very fast because it's such a fast growing industry to come up with best practice solutions, and there are many parties involved in this, obviously globally. And we're all trying to work toward a, what I would say could be a standard way of protecting these. There's been great progress made even o over the past five years. progress has transitioned into codes and standards to some extent, such as NFPA 8 55, but there is still ongoing debate on how we should be doing this. Should we be relying on deflagration venting? Should we be combining this with ventilation, for example? And something that we propose, for example, is that a layered protection concept would be adequate or would be very, very, uh, would lead to good way of safeguarding these systems. So combining ventilation and deflagration venting, for example. ongoing discussions in the expert community.

Wojciech

how about the ammonia economy With, a lot of, agricultural industry moving to use of ammonia, source of fuel in, in their processing.

Lorenz Boeck

Right. Yeah. That's another one of these hazards that we need to understand better and deal with more and more. And what I see, for example, is development of advanced CFD tools. So computational fluid, dynamic tools to model ammonia releases, dispersion and explosions. That needs to be done very carefully because of special properties of ammonia and um, also connects the world. Again, we often cannot simply focus on explosion hazards. We need to consider toxicity hazards. We need to consider the fire hazard. So very often we end up in a multiphysics hazard scenario where we need to pull in all that expertise from the explosion field, the fire field, and health and safety.

Wojciech

An extremely interesting aspect of using water to, you know, actually control the, the, the leakages and, and everything because you can actually, uh, do that. How about, how about space industry? Is that then interesting direction? Uh,

Transport Hazards: VCEs And BLEVEs

Ali Rangwala

space is huge. I mean, that's like, uh, close to $40 billion of just a private sector. Uh, so it's, it's a huge industry. Uh, and if you think of microgravity, I mean, everybody wants to, uh, wants to do something on the moon. Uh, they wanna start manufacturing stuff on the moon. They wanna start manufacturing in space. Uh, uh, now just thinking of dust, like the way dust settles on earth, gravity, it won't do that in space. you would have a completely different dust explosion hazard if you're dealing in a, a with a dust cloud in a space station, which is likely if you're starting to start manufacturing on a large scale in space. so I think the whole field of process safety as it exists right now will completely evolve when you are taking the gravity out of the picture and going to these different gravities, I mean, flammability, uh, ignition, minimum explosion concentrations, all the things that that we discussed, they all will be different. And even the method of you trying to. Calculate those uh, in, in, uh, zero gravity or a microgravity environment will have to change. So the experimental standards will also have to change. so to me it's a huge focus. And, and the main, parameter or the main hazard is an explosion because you can, you will be able to manage a fire but if you have an explosion, that's something that is just, that's it. That, that's the end of the story. and if you look at space accidents as well, I mean, many of the major accidents have essentially been explosions the, where there was a space station, the space station mayor, the first fire recorded was actually an explosion in the gas canister that then that, that basically triggered the fire. so there, uh, the, the explosion is usually the trigger for the fire. And therefore to be able to understand explosions in space, I think is a very important step. and, and especially with dust as well. I think it's a huge, uh, problem.

Wojciech

Yeah, I, I, I expose the audience of, uh, fire science show to a lot of space stuff. Uh, perhaps people may think it's a little bit weird, but I truly believe that we will very soon move from, you know, science fiction into space fire explosion, engineering as a thing because, uh, this observing how this industry is exponentially growing is,

Ali Rangwala

Yeah.

Wojciech

insane.

Ali Rangwala

Yeah, because the first thing you'd have to do if you want to do interplanetary travel is have a gas station or a fuel station that's revolving the think of a, of a patrol station or a gas station that's orbiting, and is fueling. uh, the, uh, uh, the, the space shuttles to go to Mars or to go to other planets. So the logistics involved with setting up that gas station are all related to explosion protection, essentially.

Wojciech

Fantastic. the, the feature, the feature looks, uh, really interesting for all, all types of, uh, safety engineers. Uh, it's like. I always say that human creates problems faster, that we can solve them. Therefore, our job security is unfortunately, pretty good from, from that, um, perspective. guys, we'll be wrapping up. Perhaps, uh, you would like to share with people, uh, how to enroll in that, protection engineering program. And if someone, uh, already, uh, has a master degree and they, they don't look for a master's degree perhaps, where they could, uh, you know, improve their knowledge and explosions in maybe some shorter forms, like courses or, or something.

Ali Rangwala

Yeah, so, so the program as is as currently comprises of 10 graduate courses

Wojciech

Hmm.

Emerging Frontiers: Hydrogen And Batteries

Ali Rangwala

we have divided them into three areas. Uh, the fundamentals, uh, where learn about combustion, compressible, flow dynamics, transport phenomena. And explosion dynamics. Uh, and then we have these, uh, applied engineering focus courses, that translate theory to application, which is, uh, for example, the one that Lawrence is teaching explosion, production engineering. Uh, we also have courses in this category like quantitative risk assessment, which is a translation to chemical engineering focused jobs. And then we have these CFD courses, uh, which are explosion modeling applications and explosion modeling fundamentals. so these are courses that I think have never been taught in a graduate program ever before, like a course on explosion modeling only CFDA of explosion modeling. so we have worked quite extensively to kind of get the best, instructors, the guest, the best professors to teach this. Uh, the explosion modeling application course is gonna be taught in summer, uh, by wiper blast. And Peter McDonald and, and Andrew Nicholson from Wiper Blast in the UK are teaching it online. uh, we also have courses that are very specialized. Like we have this amazing course, uh, that was taught by Vito Browski, who is the author of Electrical Fires and Explosions Handbook, ignition Handbook. Also the inventor of the Cone Kilometer. he taught this course on case studies and explosion, and this was one of the, very, very well received course. I think every single engineer out there should be taking a course like this. so the, the, the program enrollments, as I said, have already started. it's an online degree and so it offers very high flexibility for someone already working in industry and who wants to improve their credentials or learn something new. and, uh, we have a website. Uh, you can also, uh, send an email, uh, to and, and yes, and we are also very proud of the strong industry support, uh, for the program. So, for example, Lawrence teaching this course, while he's still working with Rebe is a very big deal. So we have, we, we have similar instructors who have years of experience. Like for example, the QRA course is taught by professor Steve Kumo, has around 30 years of experience at, uh, at Dubon. So, so very, practically oriented, uh, courses are also part of this, uh, this program. and like I said, I mean the, the, this, this, the need for explosion protection, uh, is truly global and urgent. we have significant in incidents across various countries. there is, uh, you know, hydrogen battery storage systems, new fuel blends, space exploration, all these areas that we already discussed, but even traditional industries. So for example, if you consider a simple product like paint, it has pigment, it has fine powder that can be combustible. And so this, adding this to all an already flammable hydrocarbon liquid. entire process of manufacturing storage, of it is an explosion hazard. Uh, so any product that you see in a store when you walk down a supermarket, for example, think of all the chemicals you have, dry powder, that may have gone into this. Its manufacturing. When you buy lipstick, it contains flammable particles, a deodorant stick. Again, it contains flammable particles. If you look at medicine, vitamin B, vitamin C, they're all explosive energy drinks. Fine powder, explosive cereal, coffee, creamer, all these products, they're, they're manufacturing, they're transport storage. It's all fundamentally coupled to an explosion hazard. look, that's what our program is structured to address these risks.

Lorenz Boeck

so besides enrolling for the whole program, uh, what I find interesting is also possible to take individual classes without actually fully enrolling at WPI, and that's especially interesting if you have a specific interest. Let's say you wanted to take a class on QRA, right? You could enroll in, I believe, up to two classes.

Ali Rangwala

Exactly.

Lorenz Boeck

normally enrolling at WPI and take those. And then what we've seen in the past, which I find fantastic, is that sometimes, you know, after taking those two classes, folks sometimes decide they want to do the whole program. So those two classes could be your entry point to the whole program, or you could just take them individually and and see it as professional development.

Wojciech

Fantastic. That, that's a great,

Ali Rangwala

Yeah.

Wojciech

that's a great opportunity. And, if the listener, if you prefer some reading, I can also recommend a good reading resources explosion, dynamics, fundamentals and practical Applications. Uh, a Handbook by Ali Ran and Robert Zilo, which is a, a good, uh. Starting point, uh, to this, uh, field of knowledge as well. It just gave me an idea for another episode. Ali, I, I probably need to, do some atex, uh, engineers, from Europe, uh, on, on how do we perform Atex protection in, in, in here, because as you said, it's, it's a part of nearly every industry, nearly every facility has a lot of those, you know, explosion zones and, and prevention of those explosion hazards. And it's, it's a whole field of industry that that could be, uh, discussed. So, so definitely there will be more explosion related episodes in, in the Fire Science Show, and for this Fire Fundamentals. I would like to thank you Ali and Lawrence. This was a great chat. Uh, huge thanks for coming to the Fire Shine Show and sharing your knowledge with, with the listeners, and I hope to see you somewhere around.

Ali Rangwala

Thanks. Thanks.

Lorenz Boeck

Thanks so much.

Wojciech

And that's it. Thank you for listening. Uh, world of Explosion is definitely quite vast. If you want to do it well, you have to build up your knowledge. I think participating in those courses by WPI or uh, or other educational opportunities that pop around out there is, uh, highly appreciated. And, if you are actually dealing a lot with, uh, those types of hazards, you probably would like to, to get up. I, I feel, uh. I feel that this is a field of competency that I could build up a little bit more and I'll consider in improving that on my end. For me, it was very interesting to learn the explosions. So far, I've considered them only through the lens of DEF Declaration detonation. I knew about the vapor cloud, explosions, ble, et cetera, because of transportation, of course, but uh, not at a level where I could, for example, model in with cd. probably that's also something that could be very, very interesting. I hope that you've got your knowledge, you got your resources to move forward. I think we've done a good job in this episode of Fire Fundamentals. So, uh, what's left to me is to thank you for being here with me. Today, thanks to Ali and Lawrence for sharing their knowledge. I hope you have great success with your master's program at WPI and to you, listener. I hope, uh, you will be thriving for more fire science and you'll come back here next Wednesday because next Wednesday we will have another pack of fire science coming your way. Thank you very much. See you round. Bye.