well i mean you are using a COMBUSTION cannon...which means there is an EXPLOSION inside of the chamber...which will of course make a FIRE...and depending on where you got the fan from there could have been oil on it...or maybe you just sprayed onto the fan...its not too hard for that to happen
Normally a fan doesnt get up in flames. There was some fuel sticked to it and surprisingly enough there was enough oxygen left in the chamber to start a small fire.
There wouldn't be enough oxygen left in the chamber to sustain a fire for more than a few milliseconds. What probably happened was you had liquid fuel (is there any ethanol or isopropanol in the rightgaurd?) one the fan and/or chamber walls. So the gun was overfueled. When fired, and at the instant the ammo exited the barrel, you had little if any oxygen left in the chamber but a small flame persisted somewhere. (EDIT: Or, you had a glowing ember.)
After the ammo left the barrel the hot combustion gases continue to expand until the chamber reached 1 ATM. The gases cooled as they expanded and continued to cool after you reached 1 ATM. The cooling gases in the gun collapsed and sucked fresh air in through the barrel. The fresh air plus the small residual flame fully ignited whatever the liquid fuel was.
If the gun is properly fueled this won't happen. Run the fan longer after fueling to get all the volatiles to vaporize. This probably means decreasing the length of time you spray in the fuel.
You cannot post new topics in this forum You cannot reply to topics in this forum You cannot edit your posts in this forum You cannot delete your posts in this forum You cannot vote in polls in this forum You cannot attach files in this forum You can download files in this forum