In organic chemistry, syntheses are often made in flammable solvents such as ether, acetone, alcohol, etc. However, these are (almost) closed systems. Usually it looks like this: Erlenmeyer flask (round flask with straight neck and ground joint) then reflux condenser (water-flowed glass coil on which the boiling solvent condenses again and runs back into the flask), then at the very top fermentation tubes with a barrier liquid, through which possible excess pressure escape can. The whole thing is heated with an electric patio heater that adapts to the shape of the piston.
Nothing happens with the arrangement.
The way you describe it, it doesn't matter if it burns down or it explodes. The fire brigade will definitely have to come.
