Airplanes must take precautions to prevent their fuel tanks from freezing. If ice forms inside of an airplane’s fuel tank, it may starve the engine or engines. Turbine engines require jet fuel. Without a constant supply of jet fuel, they won’t be able to generate propulsion. There are safeguards in place, however, to keep ice out of fuel tanks.
Can Jet Fuel Freeze?
Fuel tanks, of course, contain jet fuel. Most airplanes run on A-1. A form of kerosene, it’s the most common type of jet fuel for turbine engines. It may have a lower freezing point than plain water, but A-1 can still freeze.
The freezing point of water is minus 32 degrees Fahrenheit. The freezing point of A-1, on the other hand, is minus 47 degrees. Fahrenheit. Therefore, A-1 and other types of jet fuel can still freeze.
Pressurization
One of the ways that airplanes prevent their fuel tanks from freezing is pressurization. They pump air into their respective fuel tanks to pressurize them. Airplanes with turbine engines will typically use bleed air. They will bleed off some of the excess air from their turbine engines, rerouting it to their fuel tanks.
Pressurization helps to prevent fuel tanks from freezing. It doesn’t necessarily change the temperature of the fuel. Rather, pressurization increases the freezing point of the fuel as well as any condensation that has entered the fuel tank. Pressurized jet fuel and condensation have a higher freezing point than unpressurized jet fuel and condensation.
Heating Systems
In addition to pressurization, many airplanes use a heating system to keep ice out of their fuel tanks. Heating systems are designed to warm jet fuel. They use a heating element to produce heat and, thus, increase the temperature of the jet fuel and any condensation that has entered the fuel tank.
Many heating systems work in conjunction with a thermostat. An airplane’s fuel heating system won’t run 24/7. Instead, it will only run when the fuel is cold. A thermostat will sense the temperature of the fuel. As the temperature begins to drop, it will send a signal to the heating system. The heating system will then begin to warm the fuel until it has reached an appropriate temperature, at which point the heating system will turn off.
In Conclusion
Airplanes prevent their fuel tanks from freezing by using pressurization and a heating system. Pressurization increases the freezing point of the jet fuel, whereas a heating system increases the temperature of the jet fuel. Both safeguards will also prevent any condensation inside of the fuel tank from freezing as well.
