Being fire safety engineering students, clearly, we are all interested in the whole theoretical background of fire science, but more than anything we love actually conducting the laboratory experiments and thus seeing some proper fire live! That is the reason why probably the majority of the IMFSE students are looking forward the most to the course “Fire Science Laboratory” given by Prof Rory Hadden at the University of Edinburgh during the 3rd semester of our program.
The course consists of 5 laboratory sessions followed by a detailed report about the whole experiment. Another great thing that students usually like about the courses such as this one is that there is no exam, but the performance on the 5 laboratory sessions, together with the lab report, is assessed, and those scores combined give the final grade.
The first lab deals with a particularly interesting, and maybe not that well known phenomena of “spontaneous ignition”. Basically, in simple words, some materials, if sufficiently porous can undergo an exothermic reaction (reaction of releasing heat) generating heat faster than it can be lost. If the process lasts sufficiently long and the favorable conditions have been met, the material can auto-ignite.
In our lab, we used Milk Powder as the sample and one of the interesting things we discovered was that the bigger the size of the sample was, the smaller the auto-ignition temperatures were. In fact, apart from the ambient temperature, the most important factors determining the auto-ignition temperature are the size and the shape of the body of material involved. That’s why when transporting or storing material prone to auto-ignition it should be kept in smaller packs, rather than piled up!
The second lab was dedicated to examining two interesting terms – firepoint and flashpoint. For all the readers who are not familiar with those terms (maybe even future IMFSE students) and that are wondering what these two might mean, I highly encourage you to look them up on internet!
During the lab session, an unknown fuel was given to us, and by finding its fire and flashpoints, we were able to identify the mysterious fuel 😊
Laboratory number 3 was named “Ignition of Solids and Heat Release Rate”. It was an opportunity to work with the famous cone calorimeter! By varying the heat flux imposed by the heater to our PMMA sample, we arrived to the critical heat flux needed for our sample to ignite. Apart from being quite familiar with how a cone calorimeter apparatus works, which can be quite handy, we also saw some nice flames coming out of our PMMA sample which certainly put enlightened smiles on our faces 😉
The fourth lab was dealing with the “flame spread”. By analyzing this crucial fire characteristic, we learned a lot about all the factors and conditions affecting the flame spread positively or negatively – orientation, thickness, width, thermal properties of the sample, environmental effects etc. And yes, as we used way longer PMMA samples for this lab – we witnessed an even bigger fire this time! 🔥
The last, but not the least, lab number 5 was dedicated to the Pool fires! By burning Heptane and Diesel fuels, we analyzed how well do the theoretical correlations and calculations for the average temperature, flame height, heat release rate and air entrainment actually meet the reality. P.S. This time the fire was so big that we even had a few PhD students stopping by to see it!
All in all, after taking the course, I can say that I feel like I have deepened my fire engineering knowledge, but also that I became quite familiar with working in lab and writing proper lab reports! All of that will be more than beneficial both for my Master Thesis, but also for my future Engineering career, and a potential PhD!