Saturday, June 27, 2009

9330 BTUs

Fire Science Lab 201: 1 gallon of water can absorb 9330 BTUs as it is converted to steam and in the process it will expand 1700 times its liquid volume. So 1 gallon will become roughly 200 cubic feet of steam at conversion (212F) and then when it hits 1000 degrees F. it expands to about 400 cubic feet. (Science is cool.) So we are learning you can't just run in and spray water. You have to have space for the water to convert to steam (the process that takes heat from the fire and in doing so cools it=extinguishment) without steaming everyone. So a room filled with hot gasses and smoke, with the addition of several hundred cubic feet of REALLY HOT STEAM (4 gallons=between 800 and 1600 cubic feet(How big is your living room?)), is not an environment for a game of Parcheesi. Dry 300 degrees F is tolerable, wet 300 degrees F is a recipe for steamed firefighters, can you say L&I! So opening windows and venting the roof needs to be done to make space to safely cool the fire with water to the point of extinguishment. Hence the reason we practice cutting holes in roofs. You may ask, "How many BTUs are created by a typical fire?" (or not) Well a typical fire with the typical amount of fuel will produce around 13.2 BTUs/second/sq.ft (in English that means the ceiling will be at around 1000 degrees F in 5 minutes!)
Well the Academy has decided to keep me around for awhile. I seem to be doing well enough on the tests and on the fire ground to stay. Below are a few more pictures of the things we have been up to the last few weeks.
Oops, that was a kickball session during a study break in the shadow of Mt Si.
On to chainsaw appreciation day. We cut simulated roof vent holes with a saw and then had to do it with an axe. The trick: use the blunt end (45 seconds for a 4x8 OSB, not bad.) Then of course there is dancing in front of instructors. (It wasn't me, really.)
Low visibility day was a task. The "Lab" was filled with smoke to within inches of the floor to simulate a real fire scenario. It was hot and really hard to see, much like a real fire, cool. (The water on the floor next to the fire was boiling.) When I was in the "lab" taking the low visibility picture below I actually watched another recruit spray water on the ceiling (A technique to cool the overhead gasses.) with no water bouncing off back to the floor. 100% conversion of the water to steam!! (See note at the top of the post.) Nothing dripped to the floor! It was cool, then very VERY HOT! Oops, did I forget to check for conversion space? Why, yes, yes you did. We skedaddled out the door on our hands and knees most expediently! Later on that day after resetting the prop a hose actually burst (failed at a weak spot) and gave one recruit a full shoulder steam burn, much like a bad sunburn.
During ladder rescue day Kyle, another Edmonds FF, was my rescue firefighter and I was the victim, then the tables were turned.
Then we spent a day outside with car liquid fuel fires, apparently this prop was having a bad day.
All in all I am well, although daily I am continually pushed to my physical limit and loving the challenge.
Please continue the emails and prayers, and of course contacting Cheryl with support. Seven weeks down and five to go!
Tony