Fuel tank inerting system

Claim 2

An inerting system comprising a tank containing a liquid fuel under pressure, first means for releasing oxygen dissolved in said fuel, and second means responsive only to a predetermined drop in said pressure for actuating said first means.

Claim 3

The system of claim 1 in which said first means includes a means to introduce an inert fluid in gaseous form into said fuel below the level thereof.

Claim 4

The system of claim 1 in which there is a container separate of the tank and in communication therewith for collecting fuel vapor forming in the tank, and in which a third means automatically operates when the pressure upon the fuel bears a predetermined relationship to the ambient pressure for venting the tank to atmosphere through said container.

Claim 5

The system of claim 1 in which said first means includes a means for introducing an inert fluid into the liquid fuel through the conduit and in which there is a third means continuously supplying inert fluid to the tank through said conduit.

Claim 6

An inerting system for a fuel tank comprising a first means operable to introduce an inert fluid into the fuel tank in a manner for releasing oxygen dissolved in the fuel, and a second means automatically responsive to a reduction in ambient pressure for actuating the first means.

Claim 7

An inerting system for a fuel tank comprising a first means operable to introduce an inert fluid into the fuel tank in a manner for releasing oxygen dissolved in the fuel, and a second means automatically responsive to a reduction in ambient pressure for actuating the first means.

Claim 8

An inerting system comprising a tank containing a liquid fuel under pressure, first means for releasing oxygen dissolved in said fuel, and second means responsive to a predetermined drop in said pressure for actuating said first means, and means for establishing a reference pressure other than ambient pressure, and said predetermined drop in pressure is with respect to said reference pressure.

Claim 9

An inerting system comprising a tank containing a liquid fuel under pressure, first means for releasing oxygen dissolved in said fuel, and second means responsive to a predetermined drop in said pressure for actuating said first means, and means for establishing a reference pressure other than ambient pressure, and said predetermined drop in pressure is with respect to said reference pressure.

Claim 10

The system of claim 6 in which there is a means that reduces the reference pressure upon a predetermined drop in the pressure upon the fuel.

Claim 11

The system of claim 5 in which there is a means causing said reference pressure to drop incrementally in response to successive predetermined incremental drops in the pressure upon the fuel.

Claim 12

An inerting system comprising a tank containing a liquid fuel under pressure, first means for releasing oxygen dissolved in said fuel, second means responsive to a predetermined drop in said pressure for actuating said first means, and means for limiting operation of the first means for a predetermined time upon actuation thereof.

Claim 13

An inerting system comprising a tank containing a liquid fuel under pressure, first means for releasing oxygen dissolved in said fuel, second means responsive to a predetermined drop in said pressure for actuating said first means, and means for limiting operation of the first means for a predetermined time upon actuation thereof.

Claim 14

The system of claim 1 in which said first means includes means to introduce an inert fluid into the fuel and there is a third means to introduce additional quantities of said inert fluid into the tank.

Claim 15

An inerting system comprising a tank containing a liquid fuel under pressure, first means for releasing oxygen dissolved in said fuel, second means responsive to a predetermined drop in said pressure for actuating said first means, said predetermined drop in pressure is with respect to a reference pressure other than ambient, and in which there is a means to equalize the reference pressure with the pressure upon the fuel upon a predetermined drop in the latter to establish a new reference pressure.

Claim 16

An inerting system comprising a tank containing a liquid fuel under pressure, first means for releasing oxygen dissolved in said fuel, second means responsive to a predetermined drop in said pressure for actuating said first means, said predetermined drop in pressure is with respect to a reference pressure other than ambient, and in which there is a means to equalize the reference pressure with the pressure upon the fuel upon a predetermined drop in the latter to establish a new reference pressure.

Claim 17

An inerting system comprising a tank containing a liquid fuel under pressure, first means for releasing oxygen dissolved in said fuel, second means responsive to a predetermined drop in said pressure for actuating said first means, said first means including an inert fluid injected into said fuel from a first conduit having an opening within the tank, and third means responsive to a predetermined relationship of said fuel pressure and ambient pressure for introducing an additional supply of said inert fluid to said tank through a second conduit separate of said first conduit.

Claim 18

An inerting system comprising a tank containing a liquid fuel under pressure, first means for releasing oxygen dissolved in said fuel, second means responsive to a predetermined drop in said pressure for actuating said first means, said first means including an inert fluid injected into said fuel from a first conduit having an opening within the tank, and third means responsive to a predetermined relationship of said fuel pressure and ambient pressure for introducing an additional supply of said inert fluid to said tank through a second conduit separate of said first conduit.

Claim 19

An inerting system comprising a tank containing a liquid fuel under pressure, first means for releasing oxygen dissolved in said fuel, second means responsive to a predetermined drop in said pressure for actuating said first means, said first means including an inert fluid injected into said fuel from a first conduit having an opening within the tank, third means responsive to a predetermined relationship of said fuel pressure and ambient pressure for introducing an additional supply of said inert fluid to said tank through a second conduit separate of said first conduit, said first and second conduits branching from a common third conduit, and said fluid being supplied to said third conduit under the control of two separate valves, one of said valves being included in said first means and the other of said valves being included in said third means.

Claim 20

An inerting system comprising a tank containing a liquid fuel under pressure, first means for releasing oxygen dissolved in said fuel, second means responsive to a predetermined drop in said pressure for actuating said first means, said first means including an inert fluid injected into said fuel from a first conduit having an opening within the tank, third means responsive to a predetermined relationship of said fuel pressure and ambient pressure for introducing an additional supply of said inert fluid to said tank through a second conduit separate of said first conduit, said first and second conduits branching from a common third conduit, and said fluid being supplied to said third conduit under the control of two separate valves, one of said valves being included in said first means and the other of said valves being included in said third means.

Claim 21

The system of claim 13 in which said first conduit includes a first one-way valve openable by fluid pressure in said third conduit and through which said fluid flows from the third conduit to said first conduit, and said second conduit includes includes a second one-way valve openable by fluid pressure in said third conduit and through which said fluid is delivered from the third conduit to the tank, said second one-way valve having a higher opening pressure than the first one-way valve.

Claim 22

An inerting system comprising a tank containing liquid fuel, means for mixing a first fluid and an inert fluid and means for introducing the mixture into the tank below the level of fuel therein whereby the inert fluid forms gas bubbles within the liquid fuel in the tank to absorb oxygen dissolved in the fuel.

Claim 23

An inerting system comprising a tank containing liquid fuel, means for mixing a first fluid and an inert fluid and means for introducing the mixture into the tank below the level of fuel therein whereby the inert fluid forms gas bubbles within the liquid fuel in the tank to absorb oxygen dissolved in the fuel.

Claim 24

The system of claim 15 in which the first fluid is said fuel and the inert fluid is an inert gas, and the first fluid and gas are mixed in a scrub manifold and injected into said fuel by a means causing a wide dispersion of said gas in the fuel in the form of small bubbles that absorb oxygen from the fuel and carry it to the tank ullage.

Claim 25

The system of claim 15 in which the first fluid and the inert fluid are delivered from separate sources to a common scrub manifold for mixing therein and injection therefrom into said fuel, and there are means to prevent backflow from the manifold to each source.

Claim 26

The system of claim 17 in which the means to prevent backflow from the scrub manifold to the source of said inert fluid is a relief valve having an opening pressure greater than the delivery pressure of said first fluid into said scrub manifold to preclude flow of said first fluid to said inert fluid source when said relief valve is open.

Claim 27

The system of claim 15 in which the first fluid and said inert fluid are mixed in a manifold, said first fluid is said fuel and there is a pair of pumps that normally operate simultaneously to deliver fuel to an engine, a valve between both pumps and the manifold, said valve being response to simultaneous discharge from both pumps to deliver fuel to the manifold and being responsive to loss of discharge from either pump to cut off the flow of fuel to the manifold.

Claim 28

An inerting system comprising a tank containing liquid fuel under pressure, first means responsive to successive predetermined increments of decrease in said pressure irrespective of ambient pressure for bubbling an inert gas through said fuel to release oxygen therefrom, second means for venting the tank to atmosphere, said second means being normally closed and actuated to open position by a predetermined differential between tank pressure and atmospheric pressure.

Claim 29

An inerting system comprising a tank containing liquid fuel under pressure, first means responsive to successive predetermined increments of decrease in said pressure irrespective of ambient pressure for bubbling an inert gas through said fuel to release oxygen therefrom, second means for venting the tank to atmosphere, said second means being normally closed and actuated to open position by a predetermined differential between tank pressure and atmospheric pressure.

Claim 30

The system of claim 20 in which said increments of decrease in said fuel pressure are with respect to a reference pressure and said reference pressure is that of a fluid contained in a separate reservoir connected to said tank, a first valve between the tank and reservoir, and said first valve being responsive to a pressure differential operated device that causes the first valve to open for equalizing the tank and reservoir pressure each time the tank pressure drops a predetermined increment.

Claim 31

The system of claim 21 in which said first means includes a second valve oPerated by said device for controlling the supply of said inert gas to said fuel.

Claim 32

The system of claim 21 in which said first means includes a second valve for controlling the supply of said inert gas to said fuel, said second valve being controlled by a timer actuated by said device for maintaining said second valve in open position for a predetermined time after said first valve closes.

Claim 33

An inerting system comprising a tank containing a body of liquid fuel, a scrub manifold having an injection opening therein submerged within the fuel, means for circulating fuel from the tank into said manifold and through said opening back into said body of fuel below the level thereof, and means for introducing an inert fluid into said tank.

Claim 34

An inerting system comprising a tank containing a body of liquid fuel, a scrub manifold having an injection opening therein submerged within the fuel, means for circulating fuel from the tank into said manifold and through said opening back into said body of fuel below the level thereof, and means for introducing an inert fluid into said tank.

Claim 35

The system of claim 24 in which said circulating means includes a pair of pumps that normally operate simultaneously to supply fuel from the tank to an engine, a valve having an inlet connected to the discharge port of one pump, an outlet connected to the manifold, and a pressure chamber connected to the discharge side of the other pump, a valve member controlling flow from the inlet to the outlet, means responsive to pressure in said chamber for actuating the valve member to an open position and means responsive to pressure in said valve inlet to close said valve member when there is no pressure in the chamber.

Claim 36

An inerting system for an aircraft fuel tank containing liquid fuel under pressure, a first means responsive to a predetermined gain in altitude of said aircraft for introducing inert fluid into said tank, and a second means response to a predetermined differential between said tank pressure and ambient pressure for introducing inert fluid into said tank.

Claim 37

An inerting system for an aircraft fuel tank containing liquid fuel under pressure, a first means responsive to a predetermined gain in altitude of said aircraft for introducing inert fluid into said tank, and a second means response to a predetermined differential between said tank pressure and ambient pressure for introducing inert fluid into said tank.

Claim 38

The system of claim 26 in which there is a third means responsive to another predetermined differential between tank pressure and ambient pressure for introducing inert fluid into said tank.

Claim 39

A firs prevention system for an aircraft comprising a supply of an inert fluid in liquid form at a low temperature and under pressure, a location in the aircraft to be protected against fire, a conduit connecting said supply to said location, means communicating the interior of the conduit with said location, means controlling flow of the fluid through the conduit from the supply to the communicating means for discharge through the latter, means for maintaining the temperature of the conduit whereby the conduit serves as a heat exchanger to deliver heat

Claim 40

A firs prevention system for an aircraft comprising a supply of an inert fluid in liquid form at a low temperature and under pressure, a location in the aircraft to be protected against fire, a conduit connecting said supply to said location, means communicating the interior of the conduit with said location, means controlling flow of the fluid through the conduit from the supply to the communicating means for discharge through the latter, means for maintaining the temperature of the conduit whereby the conduit serves as a heat exchanger to deliver heat

Claim 41

A fire prevention system comprising a supply of inert fluid in liquid form at a low temperature and under pressure, means defining a space containing combustible material, a conduit connecting said supply to said space, means communicating the interior of the conduit with said space, means controlling flow of the liquid through the conduit to the communicating means, communicating means being constructed and arranged so that it discharges the liquid directly into said space in finely divided form to provide an inert atmosphere therein that is unable to support combustion within said space.

Claim 42

A fire prevention system comprising a supply of inert fluid in liquid form at a low temperature and under pressure, means defining a space containing combustible material, a conduit connecting said supply to said space, means communicating the interior of the conduit with said space, means controlling flow of the liquid through the conduit to the communicating means, communicating means being constructed and arranged so that it discharges the liquid directly into said space in finely divided form to provide an inert atmosphere therein that is unable to support combustion within said space.

Claim 43

A fire prevention system in accordance with claim 29 in which the inert liquid is nitrogen and said liquid nitrogen is isolated from other fluids between said container and said space.