Fuel tank inerting system

Claim 2

An inerting system comprising a fuel tank having space for containing a body of liquid fuel and having gases in the ullage that include an inert gas in an amount sufficient to prevent combustion of fuel vapor in the tank ullage, means for introducing liquid fuel into the tank and which fuel may contain oxygen at a higher partial pressure than the partial pressure of oxygen that may be in the ullage, means for mixing said ullage gases with incoming fuel whereby oxygen gas in the fuel is removed therefrom and combined with said mixing ullage gases, means for separating said combined gases from the incoming fuel prior to discharge of the incoming fuel into said space, and means for venting the separated gases from the tank.

Claim 3

The system of claim 1 in which the introducing means includes a filling conduit, and said mixing means includes an aspirator that connects the ullage to the filling conduit.

Claim 4

The system of claim 1 in which the separator is a container open at its top to said vent means and open at its bottom to said tank.

Claim 5

The system of claim 1 in which said mixing means and said separator means are within said tank.

Claim 6

The system of claim 1 in which said separator means includes a duct at its upper end directed toward said vent means.

Claim 7

The system of claim 1 in which there is a restricted orifice between the separator means and vent means through which said separated gases flow.

Claim 8

The system of claim 1 in which there is a separate supply of inert fluid, and there is a means for automatically injecting said fluid into the tank when the tank pressure bears a predetermined relation to ambient pressure.

Claim 9

The system of claim 3 in which there is a means for venting the tank ullage to the exterior of the tank.

Claim 10

The system of claim 3 in which the top of the separator is also open to the tank ullage.

Claim 11

The system of claim 3 in which said introducing means connects with said separator intermediate said top and bottom openings.

Claim 12

The system of claim 3 in which the container has a cylindrical portion and said mixing means includes a conduit having a rectangluar outlet that opens tangentially into said cylindrical portion.

Claim 13

The system of claim 6 in which there is an unrestricted opening between the separator and the vent means when the tank is substantially empty of liquid fuel, and means for at least partially closing said opening prior to the complete filling of the tank with liquid fuel.

Claim 14

The system of claim 12 in which said closing means includes a float operated valve.

Claim 15

The system of claim 5 in which said restricted orifice comprises the sole connection between the separator and vent means.

Claim 16

The system of claim 1 in which the separator means includes a container, a duct in said container connected to the vent means, means to circulate the incoming fuel having the combined gases therein in said container about said conduit, and circumferentially spaced openings in said conduit communicating with said container for receiving said combined gases into said conduit.

Claim 17

The system of claim 15 in which there are scoops projecting from said duct forming one side of said openings.

Claim 18

The system of claim 15 in which the circulating means causes the incoming fuel and combined gases therein to rotate in one direction about said container and there are scoops projecting from said duct to form one side of said openings, said scoops facing in said direction of rotation.

Claim 19

The system of claim 17 in which said openings are near a closed end of said duct and said incoming fuel with the combined gases therein enters the container above said openings.

Claim 20

An inerting system comprising a fuel tank having gases in the tank ullage that include a sufficient amount of inert gas to prevent combustion of fuel vapor in the tank ullage, a vent means for the tank, a conduit for introducing liquid fuel into The tank, said conduit including an aspirator and an injector tube, a gas-liquid separator comprising a container having one opening connected to the vent means and another opening connected with the tank interior, said injector tube connecting the aspirator to the separator, and means connecting the ullage to the aspirator whereby incoming liquid fuel containing oxygen dissolved therein at a partial pressure greater than the partial pressure of oxygen contained in the ullage gases and flowing through said conduit draws ullage gases through said connecting means to said aspirator and injector tube whereby the ullage gases mix with the liquid fuel therein and scrub oxygen from the latter, said scrubbed fuel and the mixed ullage gases with scrubbed oxygen therein entering the separator from the injector tube and being separated thereby, means for discharging the scrubbed liquid fuel from the separator to the tank, and means for directing the gases in the separator to said vent means.

Claim 21

An inerting system comprising a fuel tank having gases in the tank ullage that include a sufficient amount of inert gas to prevent combustion of fuel vapor in the tank ullage, a vent means for the tank, a conduit for introducing liquid fuel into The tank, said conduit including an aspirator and an injector tube, a gas-liquid separator comprising a container having one opening connected to the vent means and another opening connected with the tank interior, said injector tube connecting the aspirator to the separator, and means connecting the ullage to the aspirator whereby incoming liquid fuel containing oxygen dissolved therein at a partial pressure greater than the partial pressure of oxygen contained in the ullage gases and flowing through said conduit draws ullage gases through said connecting means to said aspirator and injector tube whereby the ullage gases mix with the liquid fuel therein and scrub oxygen from the latter, said scrubbed fuel and the mixed ullage gases with scrubbed oxygen therein entering the separator from the injector tube and being separated thereby, means for discharging the scrubbed liquid fuel from the separator to the tank, and means for directing the gases in the separator to said vent means.

Claim 22

The system of claim 19 in which said injector tube communicates with the separator intermediate the fuel discharge means and the vent means.

Claim 23

The system of claim 20 in which there is a means to prevent liquid in the separator from rising to a higher level than the connection of the injector tube to the separator when liquid level in the tank is above said connection.

Claim 24

The system of claim 19 in which there is a means for maintaining the ullage pressure higher than the pressure in the vent means.

Claim 25

The system of claim 21 in which said last mentioned means comprises a float operated valve that at least partially closed said directing means except for a restricted connection between said directing means and said separator.

Claim 26

The system of claim 23 in which said last mentioned means comprises a restricted orifice between said directing means and said separator.

Claim 27

The system of claim 21 in which said last mentioned means comprises openings in a discharge conduit which openings become partially obstructed with fuel as the fuel level rises above a predetermined location.