I just finished a batch of ABTs and then ran the egg up to 700+ to burn off the greasy drippings that missed the drip pan. It always takes a long while to cool down after a nuclear burn which is fine, but it seems like such a waste of lump to just let the egg smolder and gradually cool down. Even when you shut the bottom vent and put the cap on, the fire still takes a while to go out and the egg takes a long while to cool down. Plus there are times when I might need to shut the egg down rapidly, such as a grease or table fire or when I need to move it to a new location. So the Acme scientist in me started thinking of a fast, safe, clean, cheap, and food-safe method to rapidly extinguish and cool the egg.
I haven't completed all of my research yet but an early winner appears to be carbon dioxide. It is relatively cheap, non-toxic to animals and humans when you do not breathe in high doses, safe around food, and requires no cleanup. Liquid C02 is used in many fire extinguishers for these very reasons. It is heavier than air so it displaces the air around the fire source and immediately extinguishes the fire, plus it absorbs heat from the fire to rapidly cool the fuel down. After it disperses then it just mixes into the surrounding air and is harmless, leaving no residue or mess to clean up.
So I am thinking about getting a 5 lb. tank of C02 with a simple valve and hose attached and keeping it near the egg. When it is time to shut the egg down, I just close the bottom vent completely, insert the hose through an opening in the daisy wheel at the top of the dome, and turn the valve to release enough C02 to do the job. The egg holds the C02 inside which rapidly extinguishes the fire and cools down the egg in record time. After the fire has been out for a little while then you can just open the egg to cool it faster and disperse the C02.
According to my crude calculations, a fullly charged 5 lb. tank of C02 will hold about 350 gallons of C02 gas, and if you assume that it takes about 5 gallons to fill the bottom of the egg (allowing for small leakage at the bottom vent) then a single tank will last you for about 70 cooks which is pretty good mileage. For people that travel with small or mini eggs or that only need to use the eggstinguisher in an emergency, they could use one of the small 20 oz. C02 tanks which are designed for paintball guns. Either style tank is readily available, cheap to acquire and refill, and easy to use.
So before I head out and buy a tank to test my theory, has anyone out there actually done this? Any firemen, home brewers, soda jerks, or fellow Acme scientists in the audience that care to comment?