Fuel transfer system controlled by float valves
View Patent ↗A fuel transfer system for an aircraft includes an upper tank, a lower tank, a fuel transfer line connecting the upper tank to the lower tank, an upper fuel transfer line outlet in the lower tank, a lower fuel transfer line outlet in the lower tank, an upper float valve associated with the upper fuel transfer line outlet, and a lower float valve associated with the lower fuel transfer line outlet. The upper fuel transfer line outlet, which is in the lower tank, is in fluid communication with the upper tank. The lower fuel transfer line outlet, which is located in the lower tank, is in fluid communication with the upper tank.
1. A fuel transfer system for an aircraft comprising:
an upper tank for storing fuel;
a lower tank for storing fuel, the lower tank being disposed below the upper tank;
a fuel transfer line connecting the upper tank to the lower tank;
an upper fuel transfer line outlet in the lower tank and in fluid communication with the upper tank, wherein fuel transferred from the upper tank to the lower tank passes through the fuel transfer line and the upper fuel transfer line outlet;
a lower fuel transfer line outlet in the lower tank and in fluid communication with the upper tank, wherein fuel transferred from the upper tank to the lower tank passes through the fuel transfer line and the lower fuel transfer line outlet;
an upper float valve associated with the upper fuel transfer line outlet for opening and closing the upper fuel transfer line outlet; and
a lower float valve associated with the lower fuel transfer line outlet for opening and closing the lower fuel transfer line outlet.
2. The fuel transfer system of claim 1 being configured such that a first volume of fuel is transferred from the upper tank to the lower tank passing through the upper fuel line transfer outlet and a second remaining volume of fuel is transferred from the upper tank to the lower tank passing through the lower fuel line transfer outlet after the first volume of fuel has been transferred from the upper tank to the lower tank.
3. The fuel transfer system of claim 1 , wherein the upper tank is disposed in a fuselage of the aircraft rearward of the lower tank.
4. The fuel transfer system of claim 1 , wherein the lower tank is a center wing tank.
5. The fuel transfer system of claim 1 , wherein the upper fuel transfer line outlet is disposed above an upper tank fuel outlet, wherein fuel being transferred from the upper tank to the lower tank exits the upper tank through the upper tank fuel outlet.
6. The fuel transfer system of claim 1 , wherein the fuel transfer line includes an upper branch and a lower branch, wherein the upper fuel transfer line outlet is on the upper branch, wherein the lower fuel transfer line outlet is on the lower branch.
7. The fuel transfer system of claim 6 , wherein the fuel transfer line includes a main branch connected at a first end with an upper tank fuel outlet, wherein the upper branch and the lower branch each connect with the main branch.
8. The fuel transfer system of claim 7 , wherein the upper branch and the lower branch each are located in the lower tank.
9. The fuel transfer system of claim 7 , wherein the upper branch connects with the main branch upstream from the lower fuel transfer line outlet.
10. The fuel transfer system of claim 7 , wherein a second end of the main branch is disposed in the lower tank.
11. The fuel transfer system of claim 1 , wherein the upper fuel transfer line outlet and the lower fuel transfer line outlet are each located with respect to an upper tank fuel outlet such that fuel remains in the upper tank when a fuel level in the lower tank is below the upper fuel transfer line outlet and above the lower fuel transfer line outlet.