Title of Invention

"A DEVICE FOR GENERATING FUEL AEROSOL"

Abstract

This invention relates to a device for generating fuel aerosol using propylene oxide as a fuel characterized in that: a) a stainless steel serrated fuel container (1) filled with propylene oxide; b) a stainless steel serrated central buster tube (2) co-axially disposed within container (1) and having a cap sensitive buster charge (3) therein; c) an initiator ejection unit (7) comprising of two initiators (9, 9), housed at rear end of initiator housings (8, 8) and capable of being locked, a plunger (13) being kept in contact with front end of initiators (9), a spacer (19) to control backward movement of plunger (13), closing disc (15) gas generator (16), fixed in cavity above spacer (14) and electrical delay detonator (17); d) a probe fuze (10) comprising of multiple segment extendable mild steel housing (19), contact pin assembly (24) housed in mild steel sliding block (23) which is held in position by mild steel safety pin (20), pyro cartridge (25) and thin aluminum disc (22).

Full Text

FIELD OF INVENTION The present invention relates to a device for generating fuel aerosol. PRIOR ART Fuel aerosol generating devices have received considerable deployment acceptance in diverse civil applications like dispersing active agents into atmosphere such as pesticides, fire control agents for control of jungle/wasteland fires and oil-storage tank/well fires and also for military use like destroying natural and artificial camouflage to expose ground emplacements, defeating wheeled vehicles, neutralizing land mines etc. A typical fuel aerosol generating device disperses fuel to form saturated fuel aerosol which when detonated with an initator ejected out from (he device leads to chain of explosions. Ethylene oxide is generally used as a fuel in the known devices. There are number of devices/systems for fuel aerosol generation. One of the system known in. the art (US Patent H1 62 of Nov. 4,1986) employs a plurality of plastic containers each carrying fuel and fitted with central explosive burster charge. The explosive bursters are simultaneously detonated to form an overlapped fuel areosol. One of the disadvantages of above system is that dispersal of fuel depends upon opening up of each plastic container which is not likely to be uniform. Another disadvantage of above system is that if any part of the fuel aerosol gets ignited inadveratntly , the whole fuel aerosol formed by plastic containers may undergo ignition rather than detonation thereby affecting performance. Still another limitation of the above device is that such devices are not deliverable by aircraft or rocket. In another system known in the art (US Patent 4,297,949 ), an aerosol detonator is having a booster charge which is attached to a pyro delay detonator. The pyro delay detonator helps the booster charge to be positioned in the aerosol while at the same time providing an appropriate time interval for complete aerosol formation. The system employs striking pin mechanism for initiation of pyro delay composition. A disadvantage of above system is that the impact of the striking pin may not produce sufficient flash which may lead to failure of system. Another fuel aerosol generating system known in the art (US Patent 3,994,226 ) employs a flueric explosive initiator device having plurality of igniter devices. Each igniter device consists of small. gas container, a resonance tube and explosive charge adjacent to the closed end of the resonance tube and a nozzle connected to the gas container and communicating with housing plenum through one or more vents. A disadvantage of above system is that such a system is very complex in nature. Another system known in the art (US Patent 5,303,653 ) is a high explosive disseminator wherein explosive burster charge disperses explosive dust through a damping medium. A disadvantage of such a system is that the spread of the explosive dust becomes a function of dust grain size, dust grain density and buster charge pressure generated and the explosion set in the dust grain are instantaneous, without delay. A drawback which is common to most of the known devices is that pure Ethylene oxide is used in these devices which generates high vapour pressure of the order of 23 Psi. The high vapor pressure necessitates the use of heavy containers to withstand rupturing of fuel container at an inappropriate time. Heavy container weight affects the overall delivery parameters of the fuel aerosol generating devices. Another drawback of use of ethylene oxide in known devices is that ethylene oxide has the tendency to polymerize, when stored for long periods, thus necessitating periodic testing of filled Ethylene oxide, which may have to be replaced or whole batch of that particular lot of the stored Fuel may have to be discarded. Still another drawback of use of ethylene oxide in known fuel aerosol devices is that Ethylene oxide compositions require special arrangements to avoid possible poisoning of working staff during filling / handling operations. Some of the devices known in the art use a mixture of nearly 50 volume percent ethylene oxide and 50 volume percent propylene oxide (US Patent no 4,157,928 ) which doubles the storage life than pure ethylene oxide. One of the drawback of using a mixture of near 50 volume percent ethylene oxide and 50 volume percent propylene oxide is that due to the Polymerization of Ethylene oxide, frequent checks are still required to be made during the storage period . Another drawback of using near 50 volume percent ethylene oxide mixed with 50 volume percent propylene oxide in Fuel Aerosol generating devices is that, ethylene oxide being highly toxic, requires special arrangements to avoid causing any health hazard to working staff during filling / handling operations. Further drawback of using near 50 volume percent ethylene oxide mixed with 50 volume percent propylene oxide in Fuel Aerosol generating devices is that ethylene oxide being gas at room temperature and under atmospheric pressure requires low temperature to keep it liquid during the processing and storage. Still further drawback of using near 50 volume percent ethylene oxide mixed with 50 volume percent propylene oxide in Fuel Aerosol generating devices is that the mixture has vapour pressure of 14.5 Psi requiring robust containers to withstand rupturing of fuel container at an inappropriate time. Heavy container weight affects the overall delivery parameters of the Fuel Aerosol Cloud generating devices. OBJECTS OF THE PRESENT INVENTION The primary object of the present invention is to provide a device for generating fuel aerosol. Yet another object of the present invention is to provide a fuel aerosol generation device having superior system reliability. Yet another object of the present invention is to provide a device with increased reliability having plurality of fuel aerosol detonation mechanisms (booster mechanism) which are activated only on formation of proper fuel aerosol. Yet another object of the present invention is to provide a system for fuel aerosol having independent fuel container compartment and booster compartment which are separate units. Still another object of the present invention is to provide a device for fuel aerosol generation clearing minefield having a grenade ejection unit for jettisoning so that fuel aerosol is not activated prior to achieving proper fuel aerosol concentration, due to hot explosive gases produced by the pyro jettisoning of the grenade system. Still further object of the invention is to provide a device for fuel aerosol generation which use a fuel of 100% pure propylene Oxide which has more shelf life, and is non-hazardous during production and handling. STATEMENT OF INVENTION According to this invention there is provided a device for generating fuel aerosol using propylene oxide as a fuel characterized in that: a) a stainless steel serrated fuel container filled with propylene oxide; bj a stainless steel serrated central buster tube co-axially disposed within container and having a cap sensitive buster charge therein; c) an initiator ejection unit comprising of two initiators, housed at rear end of initiator housings and capable of being locked, a plunger being kept in contact with front end of initiators, a spacer to control backward movement of plunger, closing disc gas generator, fixed in cavity above spacer and electrical delay detonator; d) a probe fuze comprising of multiple segment extendable mild steel housing, contact pin assembly housed in mild steel sliding block which is held in position by mild steel safety pin, pyro cartridge and thin aluminum disc. DESCRITPION OF FIGURES The objects of the present invention will be more clearly understood from the following detailed description in conjunction with accompanying drawings which show an illustrative embodiment of the apparatus and are not intended to imply any limitation on the scope of the present invention. In the accompanying drawings of the apparatus, the different figures depict as follows:- Fig. 1. shows the overall construction of the device Fig.2. shows an initiator housing assembly Fig. 3. shows the construction of probefuze DETAILED DESCRITPION OF INVENTION In the present invention, the device for generating fuel aerosol uses propylene oxide {100% pure) filled in a serrated metallic container. This container contains a co-axial serrated metallic tube which is filled with an initiator composition and is so designed as to rupture the inner tube without reaching the ignition temperature of propylene oxide. This is achieved through a extendable ignition probe which hits the ground on reaching the targeted surrounding. The enhanced pressure generated in the outer serrated metallic tube due to the bursting of the inner tube is sufficient to burst it and uniformly disperse the fuel in the open. The grenade ejector assembly is initiated after a delay and throws out the grenades to a particular distance centered in the aerosol of propylene oxide. The aerosol bursts when initiated through positioned grenades and generates sufficient ground pressure to neutralise hidden landmines. The device for generating fuel aerosol uses propylene oxide as fuel and its overall construction is shown in Fig. 1. The device consists of a stainless steel serrated fuel container (1) with burster charge (3), initiator ejection unit (7) and probe fuze (10). The fuel container is filled with fuel and fitted with central burster tube (2). It is made up of stainless steel provided with equispaced vertical serrations (5). Stainless steel is selected for the container because it is compatible with propylene oxide and it also helps in withstanding stresses during handling and transportation. Besides, it is easier to provide serrations on it. The serrations on the fuel container (1) provide weak cross-sections and enable uniform bursting of container. Thereby facilitating proper dispersion of fuel in all directions unlike the dispersion from non-metallic container. The central burseter tube (2) made up of stainless steel, is fitted in the centre of the fuel container (1) along the axis to accommodate burseter charge (3). This tube is also serrated to transmit the pressure from burseter charge (3) uniformly into the liquid fuel. A cap sensitive burster charge (3) is filled in the burster tube (2) and an electrical detonator (6) is fitted as shown in Fig 1. The pressure generated by burster charge (3) breaks open the fuel container (1) and imparts sufficient energy to fuel for dispersion in air without ignition so as to have more area coverage without creating fuel lean or fuel rich zones. The metallic container (1) is fitted with proplylene oxide (4) having explosive limits of 2.5 - 37% by volume in air and producing vapour pressure of 440 mm Hg at 24 °C is used as fuel. The propylene oxide has got shelf life of more than 8 years hence is superior to ethylene oxide and propylene oxide mixtures of any proportion. An electrical detonator (6) is used to detonate the cap sensitive burster charge (3). The initiator ejection unit (7) consists of two initiators (9,9) housed, one in each initiator housing (8). The housings along with initiators are fitted inclined with respect to horizontal axis. The angle depends upon the type of device and the quantity of fuel carried. It is made up of aluminium alloy and can withstand high 'g' developed during rocket delivery or air craft delivery. Initiator housings (8,8) are two in number and positioned at 180°C to each other. Initiator housing and initiator (3) are shown in Fig 2 Fig 2 shows initiator housing and initiator. One initiaotr (9) is housed at the rear end of initiator housing and locked with the help of aluminium foil (11) and closing lid (12). A plunger (13) made of aluminium is placed in contact with the initiator's front end. The backward movement of plunger (13) is arrested with spacer (14) and closing disc (15). A gas generator (16) is centrally fixed in cavity above the spacer (14). On supply of electrical energy, the gas generator (16) produces gas pressure which ejects the initiator out of housing. Gas generator produces higher temperature gases at high pressure in the cavity. The pressure exerts force on the plunger (13). As a result, the plunger (13) and initiator(9) move outwards. The plunger (13) gets locked after travelling a small distance whereas the initiator gets ejected out by shearing the aluminium foil (11). The gas generator provides sufficient pressure to eject the initiator with required velocity. The angle and velocity of ejection of initiator (9) determines its trajectory in the fuel aerosol. Closing disc (15) is designed to withstand the setback force generated by gas generator (16) and does not allow any leakage of gases into the initiator ejection unit. Spacer is designed to provide sufficient stand-off between plunger (13) and gas generator (16). It also decides the volume available in the cavity. More over, it stops the backward movement of plunger. Plunger (13) withstands the force acting due to gas generator (16). It also acts like a interface for transmitting the force from gas generator (16) to the initiator (9). The plunger (13) gets locked after a little travel and seals completely the passage and hot gases will be trapped inside the cavity which in turn helps to avoid ignition of fuel. Closing lid (12) holds the initiator (9) with the help of aluminium foil (11) during flight/release conditions of the device. The aluminium foil (ll) is designed to control the movement of initiator (9). The thickness of aluminium foil (11) also affects the ejection velocity of initiator (9) and hence selected suitably. Initiators (9,9) are aluminium cylinders closed at front end, is filled with high explosive and each fitted with electrical delay detonator (17). The quantity of explosive filled in the initiator is sufficient to generate a strong shock for initiating the FAE cloud. One initiator is sufficient for operation. However, two initiators are employed in this device for redundancy. Electrical delay detonator (17) is contained with pyro delay composition but sealed in an aluminium capsule. The pyro delay composition and detonator composition are ignited and initiated by the supply of electrical pulse. The delay provided by the electrical delay detonator (1 7) is veiy accurate. The delay provides the initiator to travel to a proper spatial position in the fuel aerosol where the fuel is mixed with air in fine droplet form and its concentration is well within the explosive limits. Fig 3 shows the details of probe fuze (10). It consists of three segment extendable probe (18), housing (19), safety pin (20), sliding block (23), contact pin assembly (24) and pyro cartridge (25). The probe gets extended on functioning of pyro cartridge (25). The safety pin (20) is pulled out with the help of pyro body (21) thereby releasing the sliding block (23). After impact on ground the contact pin assembly which is free to move because of release of safety pin (20), moves upwards to complete the electrical circuit and energizes the explosive train consisting of gas generators (16), electrical delay detonators (13) and electrical detonator (6). Extendable probe (18) is made up of mild steel.- The inner tube is pushed outwards by the gas pressure generated by pyro cartridge (25). The inner tube gets locked.to the central tube, which further gets extended and locked to the outermost tube. The extended probe provides the required stand-off for the fuel container (1) to burst open above the ground level. The stand-off, which influence the performance of the device depends upon the quantity of fuel carried and terminal velocity of the device. House (19) is made up of mild steel to withstand the loads acting due to pyro cartridge (25) and pyro body (21). The sliding block (23) made up of mild steel and held in position with safety pin (20). It consists of contact pin assembly (24) in and pyro cartridge (25). The sliding block (23) becomes free to move only after the release of safety pin (20). Pyro cartridge (25) produces sufficient gas pressure to push the innermost tube of the extendable probe (18) so that the velocity of movement is sufficient to extend and lock the extendable probe fuze (10). The safety pin (20), made up of mild steel, holds the sliding block (23) in position and withstands the pressure generated by pyro cartridge (25). Pyrobody (25) produces sufficient gas pressure to pull the safety pin (20) by shearing thin aluminium disc (22). Thin aluminium disc (22) holds the safety pin (25) in position and withstands the load acting during the operation of pyrobody (21). The contact pin assembly (24) housed in the sliding block (23) completes the electrical circuit by moving upwards after impact of extended probe (1 8) on ground. EFFECTIVENESS OF DEVICE (Table Removed) WE CLAIM; 1. A device for generating fuel aerosol using propylene oxide as a fuel characterized in that: a) a stainless steel serrated fuel container (1) filled with propylene oxide; b) a stainless steel serrated central buster tube (2) co-axially disposed within container (1) and having a cap sensitive buster charge (3) therein; c) an initiator ejection unit (7) comprising of two initiators (9, 9), housed at rear end of initiator housings (8, 8) and capable of being locked, a plunger (13) being kept in contact with front end of initiators (9), a spacer (19) to control backward movement of plunger (13)-,-closing disc (15)-gas generator (16), fixed in cavity above spacer (14) and electrical delay detonator (17); d) a probe fuze (10) comprising of multiple segment extendable mild steel housing (19), contact pin assembly (24) housed in mild steel sliding block (23) which is held in position by mild steel safety pin (20), pyro cartridge (25) and thin aluminum disc (22). 2. A device for generating fuel aerosol as claimed in claim 1 wherein said fuel container (1) has equispaced vertical serrations (5). 3. A device for generating fuel aerosol as claimed in claim 1 wherein said initiators (9, 9) are aluminum cylinders closed at front end filled with explosive and each fitted with electrical delay detonator (17). 4. A device as claimed in claim 1 wherein said central buster tube (2) is disposed in the centre of container (1). 5. A device as claimed in claim 1 wherein said initiator is locked by an Aluminum foil (11) and closing lid (12). 6. A device for generating fuel aerosol as substantially described and illustrated herein.

Documents:

814-del-2000-abstract.pdf

814-del-2000-claims.pdf

814-del-2000-correspondence-others.pdf

814-del-2000-correspondence-po..pdf

814-del-2000-description (complete).pdf

814-del-2000-drawings.pdf

814-del-2000-form-1.pdf

814-del-2000-form-19.pdf

814-del-2000-form-2.pdf

814-del-2000-form-3.pdf

814-del-2000-gpa.pdf

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