Lo these many years ago, when I was a youth, I constructed a device in our front yard consisting of a 3lb coffee can, a candle, and a length of garden hose.
I punched a hole at the base of the can to allow the hose to enter the can. The can was filled to a depth of about an inch with flour, and a lighted candle was placed in the center of the can.
Blowing on the hose sent a cloud of flour aloft, and the candle lit the aerosol, generating a brief but wonderful flame.
The idea is to update this technique using the dryer vent which happens to vent into my front yard, adapt a microprocessor to control the vent, and have the exit aperture form the mouth of a dragon.
A bit late for this year, maybe next!-- csea, Nov 01 2013 Wusses http://www.stopkillerrobots.org/ [not_morrison_rm, Nov 04 2013] I have a propane-heated dryer...and suddenly this seems so obvious.-- Alterother, Nov 01 2013 [bigsleep] Thanks for your comment.
The invention is a novel combination of conventional techniques / processes. Not one of my finest, but possibly worthy of half-bakedness.
Incidentally, the coffee can before recycling was empty!-- csea, Nov 01 2013 One could use a pumpkin instead of a coffee can. The problem with the dragon is that what dragon belches flame straight up? Is it at a concert or something? Pumpkins, however, routinely have gouts of flame coming out of their heads.
The question: how to make repeating? I am not sure sending loads of flour / nondairy creamer or the like down the tube would produce adequate airborne density to make a gout of flame.-- bungston, Nov 02 2013 Flaming pumpkins is a good variant!
I think the airflow could work at angles close to horizontal, as long as the flour stays within the container until blown out.
The tube serves only to pass air into the reservoir of flour in the can. If memory serves, 250mL of flour is good for over 50 puffs of air. YMMV-- csea, Nov 03 2013 merely a matter of time before the NMRM orbital gatling pumpkin flour flaming device ends up on a stand in some defence industry showcase....
All profits to go into making advanced robots to go moon at members of the stop killer robots.org, which I had no idea actually existed until today. No sense of humour some people. Right, that's getting its own post.-- not_morrison_rm, Nov 04 2013 [+] good one! You were a halfbaker then and even better now!-- xandram, Nov 05 2013 Yep.Mix some metallic salts in there for effect.-- 2 fries shy of a happy meal, Nov 05 2013 random, halfbakery