Do I need a backflow preventer with a gas turbine?

Question

I made a gas turbine from a turbocharger and my fuel is propane. I have a propane regulator from a deep-fryer to regulate the fuel. Somebody told me I needed a backflow preventer to keep flames from the propane tank. Now I know this may sound crazy, but it is my understanding that there should not be a danger of an explosion because there will be no oxygen in the tank if it does happen. Fuel w/o is not a danger, or am I wrong. Plus, shouldn't the regulator prevent it? It is a modern one.

Answer 1

You are perfectly correct.

The gas leaving the regulator is at a lower pressure than that in the supply tank and, at a high velocity from the nozzle. Back-flow cannot occur.

Neither the gas nor the liquid in the tank contains any Oxygen for combustion to take place.

The gas must first mix with the air in the correct proportions before it will ignite and, this takes place at a distance from the nozzle.

The liquid must first vaporise to gas before it will burn and, as stated must also have the correct amount of air (oxygen) mixed with it in order to ignite and burn.

Answer 2

Good combustion includes vaporization in a hot zone, pressure drop to assure good cooling mixture in the combustor, and uniformity of burning. Yes, you need fuel, flame and O2 to sustain burning - and explosion. Your rig is a little unique, but follow some safeguards to avoid injury.