Early in my career I did tensile testing on adhesive coupons. I was running an experiment to simulate heating and cooling cycles on a bond. I had a nice big thermal chamber from the 1960’s, lined with heating elements (and undoubtedly asbestos), a big old dewar of liquid nitrogen, some thermocouples, and a PID controller the size of a German Shepherd.
Problem is, cold air sinks. My samples are sitting on the bottom of this huge chamber and their temperature is fluctuating wildly every time a bit of LN2 is added. The PID controller cannot cope with my shitty test setup, it’s trying to turn on the damed heaters to control the temperature and this is a multi-hour test and I just want to go home.
But… I have a cardboard box. Nice, insulative cardboard, just the right height to get my samples off the floor of the chamber and into a zone where the temperature is more stable. I am brilliant! Cardboard box deployed, I can finally begin my thermal cycling.
I learned a few things that day:
- thermal cycles include both hot and cold phases
- the floor of the thermal chamber has much less temperature stability while cooling AND while heating
- specifically the floor contains a heating element and gets ridiculously hot
- cardboard combusts at a temperature much lower than you might expect
- opening the door of a smoking thermal chamber to investigate allows in a rush of oxygen
- rapid introduction of oxygen to a smoldering cardboard box leads to very large exciting pretty flames
- fire extinguishers leave a fine dust of particles all over everything that you will be cleaning up for MONTHS
Ratio_Tile@lemmy.blahaj.zone 3 days ago
What i tell you now must never be repeated to my parents. I will deny every word, except for the latter part that resulted in me burning a hole in the driveway since they already know about that.
When I was a teen, I spilled some gas on the concrete floor of the garage while filling up the lawn mower. I thought to myself, “What’s the fastest way to clean this up?” Clearly the fastest option was to burn it. This did in fact work and produced a controllable flame, but I had neglected to move the closed plastic gas can away from the puddle of gasoline. As it turns out, plastic is made of flammable petrochemicals. The outside of it immediately caught on fire.
I realized that if the gas can lost structural integrity, gas would flood the garage floor, likely setting the whole structure ablaze. So, I picked up the flaming jug of death and ran out of the garage, setting it in the middle of the asphalt driveway downwind of any important structures. I now had the task of putting out a gasoline fire. How could I do this? Obviously, the best way to put out a fire is to spray it with a hose. So I grabbed the garden hose and aimed the nozzle at the melting jug of death.
This did not work. As it turns out, gasoline floats on water, and as such spraying water on a gasoline fire simply increases its surface area. It roared like a bonfire and the plastic can rapidly collapsed. Additionally, it turns out that asphalt is mainly composed of tar, which is a flammable petrochemical.
At some point I realized I had no idea what I was doing and called the fire department. By the time a fireman arrived, all that remained of the blaze was a smoking hole in the driveway the size of a small child, which was extinguished with a handheld chemical extinguisher.
Eh_I@lemmy.world 3 days ago
Well, that’s one way to explain the small-child sized scorch mark.
UniversalBasicJustice@quokk.au 3 days ago
Epstein victims hate this one simple trick!
…too dark? Probably too dark.
Ratio_Tile@lemmy.blahaj.zone 3 days ago
I promise I never had a little brother.
Rooskie91@discuss.online 3 days ago
Fun side hypothesis proven by this experiment: Everything is made of fossil fuels (especially if this took place in America).