methods, apparatuses, and systems for harvesting inert gas exhausted from an engine and using the harvested inert gas to prevent an ignition event and/or extinguish an ignition event. The temperature of the harvested inert gas may need to be lowered. Unwanted components may be removed from the harvested inert gas. Combustion components may be completely burned from the harvested inert gas prior to providing the harvested inert gas to a fire protection system. The fire protection system uses the harvested inert gas to extinguish an ignition event and/or to provide a purge flow to prevent an ignition event. The fire protection system may be on an aircraft. Sensors may be used to detect an ignition event. Pressure sensors may be used to monitor the pressure of the harvested inert gas as well as to monitor the purge pressure of areas receiving a continuous purge flow of harvested inert gas.

methods, apparatuses, and systems for harvesting inert gas exhausted from an engine and using the harvested inert gas to prevent an ignition event and/or extinguish an ignition event. The temperature of the harvested inert gas may need to be lowered. Unwanted components may be removed from the harvested inert gas. Combustion components may be completely burned from the harvested inert gas prior to providing the harvested inert gas to a fire protection system. The fire protection system uses the harvested inert gas to extinguish an ignition event and/or to provide a purge flow to prevent an ignition event. The fire protection system may be on an aircraft. Sensors may be used to detect an ignition event. Pressure sensors may be used to monitor the pressure of the harvested inert gas as well as to monitor the purge pressure of areas receiving a continuous purge flow of harvested inert gas.

A fuel tank inerting system includes a primary catalytic reactor comprising an inlet, an outlet, a reactive flow path between the inlet and the outlet, and a catalyst on the reactive flow path. The catalytic reactor is arranged to receive fuel from the fuel tank and air from an air source that are mixed to form a combined flow, and to react the combined flow along the reactive flow path to generate an inert gas. The system also includes an input sensor that measures a property of the combined flow before it enters the primary catalytic reactor and an output sensor that measures the property of the combined flow after it exits the primary catalytic reactor.

A fuel tank inerting system includes a primary catalytic reactor comprising an inlet, an outlet, a reactive flow path between the inlet and the outlet, and a catalyst on the reactive flow path. The catalytic reactor is arranged to receive fuel from the fuel tank and air from an air source that are mixed to form a combined flow, and to react the combined flow along the reactive flow path to generate an inert gas. The system also includes an input sensor that measures a property of the combined flow before it enters the primary catalytic reactor and an output sensor that measures the property of the combined flow after it exits the primary catalytic reactor.

Fuel tank inerting systems for aircraft are provided. The systems include a fuel tank, a catalytic reactor arranged to receive a first reactant from a first reactant source and a second reactant from a second reactant source to generate an inert gas that is supplied to the fuel tank to fill an ullage space of the fuel tank, a heat exchanger arranged between the catalytic reactor and the fuel tank and configured to at least one of cool and condense an output from the catalytic reactor to separate out the inert gas, and a controller configured to perform a light-off operation of the catalytic reactor by controlling at least one light-off parameter and, after light-off occurs, adjusting the at least one light-off parameter to an operating level, wherein the at least one light-off parameter comprises a space velocity through the catalytic reactor.

Fuel tank inerting systems for aircraft are provided. The systems include a fuel tank, a catalytic reactor arranged to receive a first reactant from a first reactant source and a second reactant from a second reactant source to generate an inert gas that is supplied to the fuel tank to fill an ullage space of the fuel tank, a heat exchanger arranged between the catalytic reactor and the fuel tank and configured to at least one of cool and condense an output from the catalytic reactor to separate out the inert gas, and a controller configured to perform a light-off operation of the catalytic reactor by controlling at least one light-off parameter and, after light-off occurs, adjusting the at least one light-off parameter to an operating level, wherein the at least one light-off parameter comprises a space velocity through the catalytic reactor.

Fuel tank inerting systems for aircraft are provided. The systems include a fuel tank, a catalytic reactor arranged to receive a first reactant from a first reactant source and a second reactant from a second reactant source to generate an inert gas that is supplied to the fuel tank to fill an ullage space of the fuel tank, a heat exchanger arranged between the catalytic reactor and the fuel tank and configured to at least one of cool and condense an output from the catalytic reactor to separate out the inert gas, and a controller configured to perform a light-off operation of the catalytic reactor by controlling at least one light-off parameter and, after light-off occurs, adjusting the at least one light-off parameter to an operating level, wherein the at least one light-off parameter comprises a space velocity through the catalytic reactor.

A fuel tank inerting system is disclosed. In addition to a fuel tank, the system includes a catalytic reactor with an inlet, an outlet, a reactive flow path between the inlet and the outlet, and a catalyst on the reactive flow path. The catalytic reactor is arranged to receive fuel from the fuel tank and air from an air source, and to react the fuel and air along the reactive flow path to generate an inert gas. The system also includes an inert gas flow path from the catalytic reactor to the fuel tank. The system also includes a non-uniform catalyst composition along the reactive flow path.

A fuel tank inerting system including: a catalytic reactor comprising an inlet, an outlet, a reactive flow path between the inlet and the outlet, a catalyst on the reactive flow path, and a temperature sensor located between the inlet and outlet, wherein the catalytic reactor is arranged to receive fuel from a fuel source and air from an air source that are mixed to form a combined flow, and to react the combined flow along the reactive flow path to generate an inert gas.

Fuel tank inerting systems for aircraft are provided. The systems include a fuel tank, a catalytic reactor arranged to receive a first reactant from a first reactant source and a second reactant from a second reactant source to generate an inert gas that is supplied to the fuel tank to fill an ullage space of the fuel tank, a condensing heat exchanger arranged between the catalytic reactor and the fuel tank and configured to at least one of cool and condense an output from the catalytic reactor to separate out the inert gas, and a controller configured to perform a light-off operation of the catalytic reactor by controlling a light-off parameter and, after light-off occurs, adjusting the light-off parameter to an operating level, wherein at least one light-off parameter comprises an air-to-fuel ratio.