Fire suppression apparatus and method

A fire suppression apparatus comprising:

• a supply of fire suppressing gas comprising a bottle containing a fire suppressing gas and a nitrogen generator;
• a water supply;
• a pneumoacoustic atomizer connected to the supply of fire suppressing gas and to the water supply, the pneumoacoustic atomizer operable to generate a mist of water droplets of a predetermined size range in a flow of fire suppressing gas when supplied with fire suppressing gas and water from by the supply of fire suppressing gas and the water supply respectively;
• a means for controlling the supply of fire suppressing gas and water to the pneumoacoustic atomizer in response to the presence of a fire including:
• a temperature sensor operable to generate a temperature signal;
• a gas control valve connected between the supply of fire suppressing gas and the pneumoacoustic atomizer;
• a water control valve connected between the water supply and the pneumoacoustic atomizer;
• a controller having the temperature signal as an input and having outputs connected to the gas control valve and the water control valve, the controller operable to open the gas control valve and the water control valve in response to the temperature signal exceeding a predetermined value;
• and
• a delay circuit connected to the water control valve and operable to delay the opening of the water control valve for a predetermined time period after the opening of the gas control valve;
• and
• a connection between the nitrogen generator and the bottle for re-filling the bottle with nitrogen during periods when fire suppressing gas is not being supplied from the bottle to the pneumoacoustic atomizer.

A fire suppression apparatus comprising:

• a supply of fire suppressing gas comprising a bottle containing a fire suppressing gas and a nitrogen generator;
• a water supply operable to supply water at a first pressure and at a second pressure lower than the first pressure;
• a pneumoacoustic atomizer connected to the supply of fire suppressing gas and to the water supply, the pneumoacoustic atomizer operable to generate a mist of water droplets of a predetermined size range in a flow of fire suppressing gas when supplied with fire suppressing gas and water from by the supply of fire suppressing gas and the water supply respectively;
• a means for controlling the supply of fire suppressing gas and water to the pneumoacoustic atomizer in response to the presence of a fire, said means for controlling being operable to control the pressure of the supply of water to the pneumoacoustic atomizer to be alternatively the first pressure and the second pressure;
• and
• a connection between the nitrogen generator and the bottle for re-filling the bottle with nitrogen during periods when fire suppressing gas is not being supplied from the bottle to the pneumoacoustic atomizer.

A fire suppression apparatus for an airplane, the fire suppression apparatus comprising:

• a nitrogen supply comprising bottled nitrogen and a nitrogen generator, the nitrogen generator being supplied with compressed air from a compressed air bleed from a turbine engine of the airplane:
• a water supply;
• a pneumoacoustic atomizer connected to the nitrogen supply and to the water supply through a nitrogen control valve and a water control valve respectively, the pneumoacoustic atomizer operable to generate a flow of nitrogen containing a mist of water droplets of a predetermined size range when supplied with nitrogen and water from the nitrogen supply and the water supply respectively;
• a fire detector;
• a controller having an input from the fire detector and having outputs operable to control the operation of the nitrogen control valve and the water control valve;
• and
• a delay circuit connected to the water control valve and operable to delay the opening of the water control valve for a predetermined time period after the opening of the nitrogen control valve.

A fire suppression apparatus for an airplane, the fire suppression apparatus comprising:

• a nitrogen supply comprising bottled nitrogen and a nitrogen generator, the nitrogen generator being supplied with compressed air from a compressed air bleed from a turbine engine of the airplane and comprising a three-way valve connected to the inlet of the pneumoacoustic atomizer, an outlet of a nitrogen storage bottle, and an outlet of the nitrogen generator;
• a water supply;
• a pneumoacoustic atomizer connected to the nitrogen supply and to the water supply through a nitrogen control valve and a water control valve respectively, the pneumoacoustic atomizer operable to generate a flow of nitrogen containing a mist of water droplets of a predetermined size range when supplied with nitrogen and water from the nitrogen supply and the water supply respectively;
• a fire detector;
• a controller having an input from the fire detector and having outputs operable to control the operation of the nitrogen control valve and the water control valve.

A fire suppression apparatus for an airplane, the fire suppression apparatus comprising:

• a nitrogen supply comprising bottled nitrogen and a nitrogen generator, the nitrogen generator being supplied with compressed air from a compressed air bleed from a turbine engine of the airplane;
• a water supply operable to supply water at a first pressure and at a second pressure lower than the first pressure;
• a pneumoacoustic atomizer connected to the nitrogen supply and to the water supply through a nitrogen control valve and a water control valve respectively, the pneumoacoustic atomizer operable to generate a flow of nitrogen containing a mist of water droplets of a predetermined size range when supplied with nitrogen and water from the nitrogen supply and the water supply respectively;
• a fire detector;
• and
• a controller having an input from the fire detector and having outputs operable to control the operation of the nitrogen control valve and the water control valve, the controller being operable to control the pressure of the water supplied to the pneumoacoustic atomizer to be alternatively the first pressure and the second pressure.

A method of suppressing a fire in an airplane, the method comprising:

• providing a supply of nitrogen in the airplane, the supply of nitrogen comprising a bottle of nitrogen and a nitrogen generator;
• providing a supply of compressed air to the nitrogen generator from an air bleed connection on a turbine engine of the airplane;
• providing a supply of water in the airplane at a first pressure and at a second pressure lower than the first pressure;
• connecting the supply of nitrogen and the supply of water to a pneumoacoustic atomizer operable to generate a mist of water droplets of a predetermined size range in a flow of nitrogen when supplied with nitrogen and water;
• detecting the presence of a fire in the airplane;
• directing the mist of water droplets in the flow of nitrogen toward the fire by initiating a flow of nitrogen and water to the pneumoacoustic atomizer from the supply of nitrogen and the supply of water respectively, the step of directing the mist of water droplets comprising initiating a flow of water at the first pressure for an initial period;
• and reducing the pressure of the supply of water to the second pressure subsequent to the initial period.

A method of suppressing a fire in an airplane, the method comprising:

• providing a supply of nitrogen in the airplane, the supply of nitrogen comprising a bottle of nitrogen and a nitrogen generator;
• providing a supply of compressed air to the nitrogen generator from an air bleed connection on a turbine engine of the airplane;
• providing a supply of water in the airplane;
• connecting the supply of nitrogen and the supply of water to a pneumoacoustic atomizer operable to generate a mist of water droplets of a predetermined size range in a flow of nitrogen when supplied with nitrogen and water;
• detecting the presence of a fire in the airplane;
• directing the mist of water droplets in the flow of nitrogen toward the fire by initiating a flow of nitrogen and water to the pneumoacoustic atomizer from the supply of nitrogen and the supply of water respectively;
• and
• delaying the initiation of the flow of water for a predetermined period after the initiation of the flow of nitrogen.

A method of suppressing a fire in an airplane, the method comprising:

• providing a supply of nitrogen in the airplane, the supply of nitrogen comprising a bottle of nitrogen and a nitrogen generator;
• providing a supply of compressed air to the nitrogen generator from an air bleed connection on a turbine engine of the airplane;
• providing a supply of water in the airplane;
• connecting the supply of nitrogen and the supply of water to a pneumoacoustic atomizer operable to generate a mist of water droplets of a predetermined size range in a flow of nitrogen when supplied with nitrogen and water;
• detecting the presence of a fire in the airplane;
• directing the mist of water droplets in the flow of nitrogen toward the fire by initiating a flow of nitrogen and water to the pneumoacoustic atomizer from the supply of nitrogen and the supply of water respectively;
• and
• providing a three-way valve for connecting the bottle alternatively to the pneumoacoustic atomizer and to the output of the nitrogen generator.

A method of suppressing a fire over an extended time period, the method comprising the steps of:

• providing a supply of nitrogen comprising at least two bottles of nitrogen and a nitrogen generator;
• providing a supply of water;
• connecting the supply of nitrogen and the supply of water to an atomizer operable to generate a mist of water droplets of a predetermined size range in a flow of nitrogen when supplied with nitrogen and water;
• detecting the presence of a fire;
• directing the mist of water droplets in the flow of nitrogen toward the fire by initiating a flow of nitrogen and water to the atomizer from the supply of nitrogen and the supply of water respectively;
• supplying nitrogen to the atomizer from alternative ones of the bottles of nitrogen while supplying nitrogen from the nitrogen generator to the ones of the bottles not supplying nitrogen to the atomizer to re-fill the bottles.