Classifications

• • A—HUMAN NECESSITIES
  • A62—LIFE-SAVING; FIRE-FIGHTING
  • A62C—FIRE-FIGHTING
  • A62C3/00—Fire prevention, containment or extinguishing specially adapted for particular objects or places
  • A62C3/07—Fire prevention, containment or extinguishing specially adapted for particular objects or places in vehicles, e.g. in road vehicles
  • A62C3/08—Fire prevention, containment or extinguishing specially adapted for particular objects or places in vehicles, e.g. in road vehicles in aircraft

Definitions

• the present invention relates to systems for the prevention of fires aboard aircraft, including aircraft which have crashed.
• the present invention makes it possible to operate a cabin spray system without the need to carry large additional quantities of water or other fluid in the aircraft. This is achieved by:
• the fire protection system for an aircraft of the type having an on-board water supply system which comprises a plurality of spray nozzles dispersed throughout the aircraft passenger cabin and a plurality of distribution conduits interconnecting the plurality of spray nozzles.
• the system also includes means for selectively connecting the distribution conduits to the aircraft's on-board water supply system.
• the distribution conduits are configured to supply each of the plurality of spray nozzles along at least two alternate flow paths whereby a redundancy is achieved.
• the fire protection system further comprises means for limiting the flow of water in the distribution conduits in the event of a rupture in one of the distribution conduits upstream of one or more of the plurality of spray nozzles.
• the fire protection system further comprises means for optionally connecting the distribution conduits to a source of pressurised water external to the aircraft, the external source connection means being positioned to be accessible to fire-fighting personnel outside the aircraft regardless of the orientation of the aircraft.
• the fire protection system for an aircraft to be supplied with pressurised water from a source external to the aircraft comprises a plurality of spray nozzles dispersed throughout the aircraft passenger cabin; conduit means located internal to the aircraft interconnecting the plurality of spray nozzles; and at least one self-sealing coupling mounted on the external fuselage of the aircraft and being interconnected with the plurality of spray nozzles by the conduit means.
• the apparatus for restricting the flow of a fluid in a conduit to a predetermined maximum value for a given fluid flow pressure drop comprises a flow restrictor housing having a through-bore, an enlarged bore portion within the housing, and an internal housing shoulder positioned at the juncture of the enlarged bore portion and the downstream part of the enlarged through-bore.
• the apparatus further includes a valve body positioned with the enlarged bore portion and movable by the action of the flowing fluid into abutment with the shoulder.
• the apparatus includes a set of flutes formed in the housing and spaced about the inner p phery of the enlarged bore position, the set of flut by-passing the shoulder.
• the flutes are ized so that the combined cross-sectional flow area yields the desired fluid flow rate value for the given fluid flow pressure drop.
• the aircraft's couplings are installed in non-pressurised parts of the aircraft. Feeder pipes 67 from the couplings to the interior sprinkler system are led through standard bulkhead fittings where they pass through the pressurised bulkheads.
• the longitudinal conduits 32,34 and transverse conduits 36 in the cabin are of titanium to save weight.
• the flexible conduits 70 in the wings are of plastic, their flexibility making it easier to pass weight.
• the flexible conduits 70 in the wings are of plastic, their flexibility making it easier to pass them through existing lightening holes in the wing ribs.
• Self-sealing couplings 66,68 are disposed so that some of the couplings will be accessible, regardless of the attitude of the aircraft. They will be supplied with water from the first tender to arrive on the scene of the accident, at a normal pressure of 9 bar (110psi). However, the sprinkler system is effective provided the pressure is no less than 2.3 bar (35 psi). Should one or both wings be sheared off in the accident, and plastic flexible conduits 70 thus become damaged, non-return valves 72 in the wing roots where the conduits join the internal conduit distribution system will close when water is applied to one or more of the other external hose couplings which remain serviceable. If the wing is intact, but on fire, then the plastic conduit will survive if it is full of water. If the plastic conduit 70 is destroyed by fire before it is filled with water via its respective coupling 68, then, again, any of the other couplings 66 can be used by the firemen to drench the cabin.
• the sprinkler nozzles are arranged in groups along longitudinal conduits 32,34 with flow restrictors 38 between those groups.
• the flow restrictors "choke", limiting the quantity of water which can spill from the fractured conduit ends to that quantity which would normally have been supplied to the sprayers on the broken-off section. This will ensure that all spray nozzles 28 supplied with water will function as intended.
• Flow restrictors 38 are of a novel but simple and reliable design which enables when to restrict to two different flow values, depending upon the direction of water flow. Thus, it is possible to ensure successful drenching of the cabin 14, no matter where along the conduit length a fracture occurs.
• the weight of the system 10 is estimated as 45 kg (1001b.) for a Boeing 737 installation, and this low figure would be acceptable to any airline interested in passenger safety.
• Figure 1 is an overall schematic view of one embodiment of the aircraft fire control system, made in accordance with the present invention.
• Figure 2 is a schematic showing a portion of the aircraft fire control system depicted in Figure 1;
• FIG 3 is a schematic detail of the flow restrictor element of the aircraft fire control system depicted in Figure 1.
• FIG. 1 With initial reference to Figure 1, there is shown an aircraft fire protection system constructed in accordance with the present invention and designated generally by the numeral 10.
• Fire protection system 10 is shown installed in aircraft 12 (shown in dotted lines) having passenger cabin 14 disposed along the aircraft longitudinal axis 16 and wings 18,20 defining the transverse direction.
• the aircraft depicted in Figure 1 is of the type having an on-board "domestic" water supply system 22.
• domestic water supply system 22 includes clean water reservoir 24 and used water reservoir 26.
• the aircraft fire protection system includes a plurality of spray nozzles dispersed throughout the aircraft cabin.
• a plurality of sprinkler heads 28 are arrayed along cabin 14 and directed to provide coverage to all occupied parts of cabin 14.
• the individual nozzles 28 can be directed from below, as well as from the side and from above, the passenger seating positions, and configured and sized to provide mist or shower-type sprays.
• Sprinkler heads should be operable at least over the range of water supply pressures of about 35 psi to 110 psi.
• One skilled in the art would be able to construct and position suitable sprinkler heads given current knowledge in the art and the present specification.
• conduit means designated generally by the numeral 30 includes a plurality of longitudinal conduits 32,34 running the length of cabin 14, with at least one longitudinal conduit on each transverse side of axis 16.
• a plurality (e.g., three or more) of longitudinal conduits 32, 34 are used on each transverse side, although Figure 1 only shows one each for purposes of clarity.
• Longitudinal conduits 32,34 should be strong but relatively lightweight, and titanium conduits are preferred. These can be run along the non-pressurised space outside the cabin, with only the spray nozzles penetrating the pressurised portion.
• Conduit means 30 further includes at least one transverse conduit 36 for interconnecting longitudinal conduits 32, 34.
• a plurality of transverse conduits 36 (three being shown in Figure 1), spaced along axis 16 are employed to achieve a redundancy in the water supply flow path to each spray nozzle 28.
• transverse conduits 36 are closed ringtype, which act like distribution plenums. In the event of an aircraft crash followed by rupture of one of longitudinal conduits 32,34 and/or transverse conduits 36 there would exist an alternative flow to each spray nozzle 28, as can be appreciated from studying the configuration of conduit means 30 in Figure 1.
• flow restrictors 38 are placed in longitudinal conduits 32,34 between groups of spray nozzles 28 to limit or "choke" the flow that would leak out of the ruptured conduit downstream of the restrictor.
• flow restrictors 38 are sized to limit the rupture flow rate to approximately that of the combined downstream spray nozzle capacity, and it is further preferred that the flow restrictors be "two-way” to accommodate the alternate redundant flow path design.
• a novel flow restrictor 38 which is simple in design and which can be constructed to have two different choke flow rates. depending on flow direction, is discussed henceforth.
• the twoway flow restrictor includes a housing with a throughbore and an enlarged bore portion capturingly holding a valve body.
• flow restrictor 38 includes housing 40 with through-bore 42, a central portion 44 of which is enlarged in cross-sectional diameter. Respective internal shoulders 46, 48 are formed in the housing at the junctures of portions 50,52 of the through-bore 42 and enlarged bore portion 44.
• Ball type valve body 54 is positioned in enlarged bore portion 44 and is movable by action of the flowing fluid into engagement with either of shoulder 46,48, depending upon the direction of fluid flow.
• flutes are provided spaced about the internal periphery of the housing and by-passing the respective shoulders to provide a predetermined flow path past the valve body.
• two sets of flutes 56,58 are formed in the internal periphery of housing 40 to by-pass shoulders 46,48, respectively.
• the flutes in sets 56 and 58 are of different size to provide a different preselected "choke” flow rate.
• the "choke" flow rate for fluid flow right to left in Figure 3 would be greater than that "choke” flow rate in the opposite direction owing to the larger sizes of the flutes in set 58 relative to set 56.
• the aircraft fire protection system includes means for selectively connecting said distribution conduits to the aircraft on-board water supply system.
• selective connection means designated generally by the numeral 60 is shown connecting domestic water supply system 22 with the centrally located one of transverse ring-type conduits 36.
• Other connection locations are, of course, possible due to the interconnections of conduit means 30, as well as a connection between supply systems 22 and one of longitudinal conduits 32,34.
• selective connection means 60 can, for example, include water pump 62 and non-return valve 64 in series and change over valve 64 selectively connectable to clean water reservoir 24, used water reservoir 26, individually, or both, simultaneously.
• the aircraft fire protection system can also include means for optionally connecting the distribution conduits to a source of pressurised water external to the aircraft.
• a plurality of self-sealing couplings 66 are distributed about the external aircraft fuselage on both sides of the aircraft and are individually connected via feeder pipes 67 to transverse conduits 36 at the front and rear of the aircraft. This distribution should allow at least one of self-sealing couplings 66 to be accessible to fire fighting personnel for virtually any non-standard orientation of the aircraft, such as following a crash where the aircraft may be on its side or have some fuselage portions damage.
• Additional self-sealing couplings 68 can be located at the wing tips and can be connected to the central one of transverse conduits 36 via flexible conduits 70 in which are disposed nonreturn valves 72 located near the wing roots due to the high propensity for the wings to be sheared off following a crash landing.
• Flexible conduits can be fabricated from plastic piping to provide the required flexibility.
• the present invention relates to systems for the prevention of fires aboard aircraft, including aircraft which have crashed.
• the present invention makes it possible to operate a cabin spray system without the need to carry large additional quantities of water or other fluid in the aircraft. This is achieved by:
• the fire protection system for an aircraft of the type having an on-board water supply system which comprises a plurality of spray nozzles dispersed throughout the aircraft passenger cabin and a plurality of distribution conduits interconnecting the plurality of spray nozzles.
• the system also includes means for selectively connecting the distribution conduits to the aircraft's on-board water supply system.
• the distribution conduits are configured to supply each of the plurality of spray nozzles along at least two alternate flow paths whereby a redundancy is achieved.
• the fire protection system further comprises means for limiting the flow of water in the distribution conduits in the event of a rupture in one of the distribution conduits upstream of one or more of the plurality of spray nozzles.
• the fire protection system further comprises means for optionally connecting the distribution conduits to a source of pressurised water external to the aircraft, the external source connection means being positioned to be accessible to fire-fighting personnel outside the aircraft regardless of the orientation of the aircraft.
• the fire protection system for an aircraft to be supplied with pressurised water from a source external to the aircraft comprises a plurality of spray nozzles dispersed throughout the aircraft passenger cabin; conduit means located internal to the aircraft interconnecting the plurality of spray nozzles; and at least one self-sealing coupling mounted on the external fuselage of the aircraft and being interconnected with the plurality of spray nozzles by the conduit means.
• the apparatus for restricting the flow of a fluid in a conduit to a predetermined maximum value for a given fluid flow pressure drop comprises a flow restrictor housing having a through-bore, an enlarged bore portion within the housing, and an internal housing shoulder positioned at the juncture of the enlarged bore portion and the downstream part of the enlarged through-bore.
• the apparatus further includes a valve body positioned with the enlarged bore portion and movable by the action of the flowing fluid into abutment with the shoulder.
• the apparatus includes a set of flutes formed in the housing and spaced about the i r periphery of the enlarged bore position, the set o utes by-passing the shoulder.
• the flutes are sized so that the combined cross-sectional flow area yields the desired fluid flow rate value for the given fluid flow pressure drop.
• the aircraft's couplings are installed in non-pressurised parts of the aircraft. Feeder pipes 61 from the couplings to the interior sprinkler system are led through standard bulkhead fittings where they pass through the pressurised bulkheads.
• the longitudinal conduits 32,34 and transverse conduits 36 in the cabin are of titanium to save weight.
• the flexible conduits 70 in the wings are of plastic, their flexibility making it easier to pass weight.
• the flexible conduits 70 in the wings are of plastic, their flexibility making it easier to pass them through existing lightening holes in the wing ribs.
• Self-sealing couplings 66,68 are disposed so that some of the couplings will be accessible, regardless of the attitude of the aircraft. They will be supplied with water from the first tender to arrive on the scene of the accident, at a normal pressure of 9 bar (110psi). However, the sprinkler system is effective provided the pressure is no less than 2.3 bar (35 psi). Should one or both wings be sheared off in the accident, and plastic flexible conduits 70 thus become damaged, non-return valves 72 in the wing roots where the conduits join the internal conduit distribution system will close when water is applied to one or more of the other external hose couplings, which remain serviceable. If the wing is intact, but on fire, then the plastic conduit will survive if it is full of water. If the plastic conduit 70 is destroyed by fire before it is filled with water via its respective coupling 68, then, again, any of the other couplings 66 can be used by the firemen to drench the cabin.
• the sprinkler nozzles are arranged in groups along longitudinal conduits 32,34 with flow restrictors 38 between those groups.
• the flow restrictors "choke", limiting the quantity of water which can spill from the fractured conduit ends to that quantity which would normally have been supplied to the sprayers on the broken-off section. This will ensure that all spray nozzles 28 supplied with water will function as intended.
• Flow restrictors 38 are of a novel but simple and reliable design which enables when to restrict to two different flow values, depending upon the direction of water flow. Thus, it is possible to ensure successful drenching of the cabin 14, no matter where along the conduit length a fracture occurs.
• the weight of the system 10 is estimated as 45 kg (1001b.) for a Boeing 737 installation, and this low figure would be acceptable to any airline interested in passenger safety.
• Figure 1 is an overall schematic view of one embodiment of the aircraft fire control system, made in accordance with the present invention.
• Figure 2 is a schematic showing a portion of the aircraft fire control system depicted in Figure 1;
• FIG 3 is a schematic detail of the flow restrictor element of the aircraft fire control system depicted in Figure 1.
• FIG. 1 With initial reference to Figure 1, there is shown an aircraft fire protection system constructed in accordance with the present invention and designated generally by the numeral 10.
• Fire protection system 10 is shown installed in aircraft 12 (shown in dotted lines) having passenger cabin 14 disposed along the aircraft longitudinal axis 16 and wings 18,20 defining the transverse direction.
• the aircraft depicted in Figure 1 is of the type having an on-board "domestic" water supply system 22.
• domestic water supply system 22 includes clean water reservoir 24 and used water reservoir 26.
• the aircraft fire protection system includes a plurality of spray nozzles dispersed throughout the aircraft cabin.
• a plurality of sprinkler heads 28 are arrayed along cabin 14 and directed to provide coverage to all occupied parts of cabin 14.
• the individual nozzles 28 can be directed from below, as well as from the side and from above, the passenger seating positions, and configured and sized to provide mist or shower-type sprays.
• Sprinkler heads should be operable at least over the range of water supply pressures of about 35 psi to 110 psi.
• One skilled in the art would be able to construct and position suitable sprinkler heads given current knowledge in the art and the present specification.
• conduit means designated generally by the numeral 30 includes a plurality of longitudinal conduits 32,34 running the length of cabin 14, with at least one longitudinal conduit on each transverse side of axis 16.
• a plurality (e.g., three or more) of longitudinal conduits 32, 34 are used on each transverse side, although Figure 1 only shows one each for purposes of clarity.
• Longitudinal conduits 32,34 should be strong but relatively lightweight, and titanium conduits are preferred. These can be run along the non-pressurised space outside the cabin, with only the spray nozzles penetrating the pressurised portion.
• Conduit means 30 further includes at least one transverse conduit 36 for interconnecting longitudinal conduits 32, 34.
• a plurality of transverse conduits 36 (three being shown in Figure 1), spaced along axis 1 6 are employed to achieve a redundancy in the water supply flow path to each spray nozzle 28.
• transverse conduits 36 are closed ringtype, which act like distribution plenums. In the event of an aircraft crash followed by rupture of one of longitudinal conduits 32,34 and/or transverse conduits 36 there would exist an alternative flow to each spray nozzle 28, as can be appreciated from studying the configuration of conduit means 30 in Figure 1.
• flow restrictors 38 are placed in longitudinal conduits 32,34 between groups of spray nozzles 28 to limit or "choke" the flow that would leak out of the ruptured conduit downstream of the restrictor.
• flow restrictors 38 are sized to limit the rupture flow rate to approximately that of the combined downstream spray nozzle capacity, and it is further preferred that the flow restrictors be "two-way” to accommodate the alternate redundant flow path design.
• a novel flow restrictor 38 which is simple in design and which can be constructed to have two different choke flow rates, depending on flow direction, is discussed henceforth.
• the twoway flow restrictor includes a housing with a throughbore and an enlarged bore portion capturingly holding a valve body.
• flow restrictor 38 includes housing 40 with through-bore 42, a central portion 44 of which is enlarged in cross-sectional diameter. Respective internal shoulders 46, 48 are formed in the housing at the junctures of portions 50,52 of the through-bore 42 and enlarged bore portion 44.
• Ball type valve body 54 is positioned in enlarged bore portion 44 and is movable by action of the flowing fluid into engagement with either of shoulder 46,48, depending upon the direction of fluid flow.
• flutes are provided spaced about the internal periphery of the housing and by-passing the respective shoulders to provide a predetermined flow path past the valve body.
• two sets of flutes 56,58 are formed in the internal periphery of housing 40 to by-pass shoulders 46,48, respectively.
• the flutes in sets 56 and 58 are of different size to provide a different preselected "choke” flow rate.
• the "choke" flow rate for fluid flow right to left in Figure 3 would be greater than that "choke” flow rate in the opposite direction owing to the larger sizes of the flutes in set 58 relative to set 56.
• the aircraft fire protection system includes means for selectively connecting said distribution conduits to the aircraft on-board water supply system.
• selective connection means designated generally by the numeral 60 is shown connecting domestic water supply system 22 with the centrally located one of transverse ring-type conduits 36.
• Other connection locations are, of course, possible due to the interconnections of conduit means 30, as well as a connection between supply systems 22 and one of longitudinal conduits 32,34.
• selective connection means 60 can, for example, include water pump 62 and non-return valve 64 in series and change over valve 64 selectively connectable to clean water reservoir 24, used water reservoir 26, individually, or both, simultaneously.
• the aircraft fire protection system can also include means for optionally connecting the distribution conduits to a source of pressurised water external to the aircraft.
• a plurality of self-sealing couplings 66 are distributed about the external aircraft fuselage on both sides of the aircraft and are individually connected via feeder pipes 67 to transverse conduits 36 at the front and rear of the aircraft. This distribution should allow at least one of self-sealing couplings 66 to be accessible to fire fighting personnel for virtually any non-standard orientation of the aircraft, such as following a crash where the aircraft may be on its side or have some fuselage portions damage.
• Additional self-sealing couplings 68 can be located at the wing tips and can be connected to the central one of transverse conduits 36 via flexible conduits 70 in which are disposed nonreturn valves 72 located near the wing roots due to the high propensity for the wings to be sheared off following a crash landing.
• Flexible conduits can be fabricated from plastic piping to provide the required flexibility.
• the present invention relates to systems for the prevention of fires aboard aircraft, including aircraft which have crashed.
• the present invention makes it possible to operate a cabin spray system without the need to carry large additional quantities of water or other fluid in the aircraft. This is achieved by:
• the fire protection system for an aircraft of the type having an on-board water supply system which comprises a plurality of spray nozzles dispersed throughout the aircraft passenger cabin and a plurality of distribution conduits interconnecting the plurality of spray nozzles.
• the system also includes means for selectively connecting the distribution conduits to the aircraft's on-board water supply system.
• the distribution conduits are configured to supply each of the plurality of spray nozzles along at least two alternate flow paths whereby a redundancy is achieved.
• the fire protection system further comprises means for limiting the flow of water in the distribution conduits in the event of a rupture in one of the distribution conduits upstream of one or more of the plurality of spray nozzles.
• the fire protection system further comprises means for optionally connecting the distribution conduits to a source of pressurised water external to the aircraft, the external source connection means being positioned to be accessible to fire-fighting personnel outside the aircraft regardless of the orientation of the aircraft.
• the fire protection system for an aircraft to be supplied with pressurised water from a source external to the aircraft comprises a plurality of spray nozzles dispersed throughout the aircraft passenger cabin; conduit means located internal to the aircraft interconnecting the plurality of spray nozzles; and at least one self-sealing coupling mounted on the external fuselage of the aircraft and being interconnected with the plurality of spray nozzles by the conduit means.
• the apparatus for restricting the flow of a fluid in a conduit to a predetermined maximum value for a given fluid flow pressure drop comprises a flow restrictor housing having a through-bore, an enlarged bore portion within the housing, and an internal housing shoulder positioned at the juncture of the enlarged bore portion and the downstream part of the enlarged through-bore.
• the apparatus further includes a valve body positioned with the enlarged bore portion and movable by the action of the flowing fluid into abutment with the shoulder.
• the apparatus includes a set of flutes formed in the housing and spaced about the inner periphery of the enlarged bore position, the set of flutes by-passing the shoulder.
• the flutes are sized so that the combined cross-sectional flow area yields the desired fluid flow rate value for the given fluid flow pressure drop.
• the aircraft's couplings are installed in non-pressurised parts of the aircraft. Feeder pipes 67 from the couplings to the interior sprinkler system are led through standard bulkhead fittings where they pass through the pressurised bulkheads.
• the longitudinal conduits 32,34 and transverse conduits 36 in the cabin are of titanium to save weight.
• the flexible conduits 70 in the wings are of plastic, their flexibility making it easier to pass weight.
• the flexible conduits 70 in the wings are of plastic, their flexibility making it easier to pass them through existing lightening holes in the wing ribs.
• Self-sealing couplings 66,68 are disposed so that some of the couplings will be accessible, regardless of the attitude of the aircraft. They will be supplied with water from the first tender to arrive on the scene of the accident, at a normal pressure of 9 bar (110psi). However, the sprinkler system is effective provided the pressure is no less than 2.3 bar (35 psi). Should one or both wings be sheared off in the accident, and plastic flexible conduits 70 thus become damaged, non-return valves 72 in the wing roots where the conduits join the internal conduit distribution system will close when water is applied to one or more of the other external hose couplings which remain serviceable. If the wing is intact, but on fire, then the plastic conduit will survive if it is full of water. If the plastic conduit 70 is destroyed by fire before it is filled with water via its respective coupling 68, then, again, any of the other couplings 66 can be used by the firemen to drench the cabin.
• the sprinkler nozzles are arranged in groups along longitudinal conduits, 32,34 with flow restrictors 38 between those groups.
• the flow restrictors "choke", limiting the quantity of water which can spill from the fractured conduit ends to that quantity which would normally have been supplied to the sprayers on the broken-off section. This will ensure that all spray nozzles 28 supplied with water will function as intended.
• Flow restrictors 38 are of a novel but simple and reliable design which enables when to restrict to two different flow values, depending upon the direction of water flow. Thus, it is possible to ensure successful drenching of the cabin 14, no matter where along the conduit length a fracture occurs.
• the weight of the system 10 is estimated as 45 kg (1001b.) for a Boeing 737 installation, and this low figure would be acceptable to any airline interested in passenger safety.
• Figure 1 is an overall schematic view of one embodiment of the aircraft fire control system, made in accordance with the present invention.
• Figure 2 is a schematic showing a portion of the aircraft fire control system depicted in Figure 1;
• FIG 3 is a schematic detail of the flow restrictor element of the aircraft fire control system depicted in Figure 1.
• FIG. 1 With initial reference to Figure 1, there is shown an aircraft fire protection system constructed in accordance with the present invention and designated generally by the numeral 10.
• Fire protection system 10 is shown installed in aircraft 12 (shown in dotted lines) having passenger cabin 14 disposed along the aircraft longitudinal axis 16 and wings 18,20 defining the transverse direction.
• the aircraft depicted in Figure 1 is of the type having an on-board "domestic" water supply system 22.
• domestic water supply system 22 includes clean water reservoir 24 and used water reservoir 26.
• the aircraft fire protection system includes a plurality of spray nozzles dispersed throughout the aircraft cabin.
• a plurality of sprinkler heads 28 are arrayed along cabin 14 and directed to provide coverage to all occupied parts of cabin 14.
• the individual nozzles 28 can be directed from below, as well as from the side and from above, the passenger seating positions, and configured and sized to provide mist or shower-type sprays.
• Sprinkler heads should be operable at least over the range of water supply pressures of about 35 psi to 110 psi.
• One skilled in the art would be able to construct and position suitable sprinkler heads given current knowledge in the art and the present specification.
• conduit means designated generally by the numeral 30 includes a plurality of longitudinal conduits 32,34 running the length of cabin 14, with at least one longitudinal conduit on each transverse side of axis 16.
• a plurality (e.g., three or more) of longitudinal conduits 32, 34 are used on each transverse side, although Figure 1 only shows one each for purposes of clarity.
• Longitudinal conduits 32,34 should be strong but relatively lightweight, and titanium conduits are preferred. These can be run along the non-pressurised space outside the cabin, with only the spray nozzles penetrating the pressurised portion.
• Conduit means 30 further includes at least one transverse conduit 36 for interconnecting longitudinal conduits 32, 34.
• a plurality of transverse conduits 36 (three being shown in Figure 1), spaced along axis 16 are employed to achieve a redundancy in the water supply flow path to each spray nozzle 28.
• transverse conduits 36 are closed ringtype, which act like distribution plenums. In the event of an aircraft crash followed by rupture of one of longitudinal conduits 32,34 and/or transverse conduits 36 there would exist an alternative flow to each spray nozzle 28, as can be appreciated from studying the configuration of conduit means 30 in Figure 1.
• flow restrictors 38 are placed in longitudinal conduits 32,34 between groups of spray nozzles 28 to limit or "choke" the flow that would leak out of the ruptured conduit downstream of the restrictor.
• flow restrictors 38 are sized to limit the rupture flow rate to approximately that of the combined downstream spray nozzle capacity, and it is further preferred that the flow restrictors be "two-way” to accommodate the alternate redundant flow path design.
• a novel flow restrictor 38 which is simple in design and which can be constructed to have two different choke flow rates. depending on flow direction, is discussed henceforth.
• the twoway flow restrictor includes a housing with a throughbore and an enlarged bore portion capturingly holding a valve body.
• flow restrictor 38 includes housing 40 with through-bore 42, a central portion 44 of which is enlarged in cross-sectional diameter. Respective internal shoulders 46, 48 are formed in the housing at the junctures of portions 50,52 of the through-bore 42 and enlarged bore portion 44.
• Ball type valve body 54 is positioned in enlarged bore portion 44 and is movable by action of the flowing fluid into engagement with either of shoulder 46,48, depending upon the direction of fluid flow.
• flutes are provided spaced about the internal periphery of the housing and by-passing the respective shoulders to provide a predetermined flow path past the valve body.
• two sets of flutes 56,58 are formed in the internal periphery of housing 40 to by-pass shoulders 46,48, respectively.
• the flutes in sets 56 and 58 are of different size to provide a different preselected "choke” flow rate.
• the "choke" flow rate for fluid flow right to left in Figure 3 would be greater than that "choke” flow rate in the opposite direction owing to the larger sizes of the flutes in set 58 relative to set 56.
• the aircraft fire protection system includes means for selectively connecting said distribution conduits to the aircraft on-board water supply system.
• selective connection means designated generally by the numeral 60 is shown connecting domestic water supply system 22 with the centrally located one of transverse ring-type conduits 36.
• Other connection locations are, of course, possible due to the interconnections of conduit means 30, as well as a connection between supply systems 22 and one of longitudinal conduits 32,34.
• selective connection means 60 can, for example, include water pump 62 and non-return valve 64 in series and change over valve 64 selectively connectable to clean water reservoir 24, used water reservoir 26, individually, or both, simultaneously.
• the aircraft fire protection system can also include means for optionally connecting the distribution conduits to a source of pressurised water external to the aircraft.
• a plurality of self-sealing couplings 66 are distributed about the external aircraft fuselage on both sides of the aircraft and are individually connected via feeder pipes 67 to transverse conduits 36 at the front and rear of the aircraft. This distribution should allow at least one of self-sealing couplings 66 to be accessible to fire fighting personnel for virtually any non-standard orientation of the aircraft, such as following a crash where the aircraft may be on its side or have some fuselage portions damage.
• Additional self-sealing couplings 68 can be located at the wing tips and can be connected to the central one of transverse conduits 36 via flexible conduits 70 in which are disposed nonreturn valves 72 located near the wing roots due to the high propensity for the wings to be sheared off following a crash landing.
• Flexible conduits can be fabricated from plastic piping to provide the required flexibility.

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• Health & Medical Sciences (AREA)
• Public Health (AREA)
• Business, Economics & Management (AREA)
• Emergency Management (AREA)
• Fire-Extinguishing By Fire Departments, And Fire-Extinguishing Equipment And Control Thereof (AREA)
• Nozzles (AREA)
• Taps Or Cocks (AREA)
• Check Valves (AREA)
• Retarders (AREA)
• Insulated Conductors (AREA)
• Emergency Protection Circuit Devices (AREA)

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Citations (6)

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• 1987
  • 1987-11-17 WO PCT/GB1987/000815 patent/WO1989004693A1/en not_active Ceased
  • 1987-11-17 AU AU82727/87A patent/AU8272787A/en not_active Abandoned
  • 1987-11-17 EP EP87907516A patent/EP0389469B1/en not_active Expired - Lifetime
  • 1987-11-17 DE DE8787907516T patent/DE3783470D1/de not_active Expired - Lifetime
  • 1987-11-17 AT AT87907516T patent/ATE84233T1/de not_active IP Right Cessation
• 1988
  • 1988-03-23 IN IN190/MAS/88A patent/IN170786B/en unknown
• 1990
  • 1990-08-16 US US07/569,220 patent/US5040611A/en not_active Expired - Fee Related

Patent Citations (6)

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