GAS GENERATOR WITH COOLANT EXPULSION MEANS
First Claim
1. A device for effecting, in a very short time, a large release of cooled gases obtained by combustion of a propellant and cooling of the combustion gases to a moderate temperature by vaporisation of a liquid, said device comprising a hollow body made from a pressurE-resistant material, the interior of which is divided by a wall into two separate chambers, said wall preventing fluid flow between said chambers, one of said chambers being a reservoir chamber containing a vaporisable liquid and the other of said chambers being a combustion chamber containing a solid propellant, an ignition device for said propellant in said combustion chamber, means forming a gas-liquid mixing chamber adjacent said two chambers, first orifice means in the wall of said reservoir chamber and extending from said reservoir chamber to said mixing chamber, second orifice means extending from said combustion chamber to said mixing chamber to permit the flow of combustion gases from said combustion chamber directly into said mixing chamber, said second orifice means being in a direction perpendicular to the flow of gases before the gases enter therein and also perpendicular to the flow of liquid, said liquid and said gases traveling perpendicularly and forming an eddy flow within the mixing chamber, said wall which separates the two chambers comprising at least one movable portion which is movable by the gases in said combustion chamber to bring about a decrease in volume of the reservoir chamber under the action of the pressure of gases resulting from the combustion of said propellant in order to expel the liquid from said reservoir chamber through said orifice means in the wall thereof into said mixing chamber, whereby upon ignition of said propellant, combustion gases and said liquid separately flow into said mixing chamber and mixing of the combustion gases of the propellant with the liquid expelled from the reservoir and vaporisation of the said liquid in contact with the said gases causes instantaneous cooling of said gases.
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Accused Products
Abstract
This invention relates to a device comprising a reservoir for containing a liquid, a combustion chamber containing a solid propellant with an ignition device therefor, said chamber and said reservoir comprising a separating wall at least partially deformable or movable to effect a decrease in volume of the reservoir under the action of the pressure of the gases resulting from combustion of the propellant, for expelling instantaneously the said liquid from the said reservoir, calibrated orifices also being provided to place said reservoir in communication with an output tube. If desired, other calibrated orifices may be provided to link the combustion chamber with the outlet tube. This device may be used for effecting a large release of gases in a very short time, e.g., for filling an expansible bag or cushion used, for example, as a safety device for protecting the passengers of an automobile vehicle.
44 Citations
13 Claims
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1. A device for effecting, in a very short time, a large release of cooled gases obtained by combustion of a propellant and cooling of the combustion gases to a moderate temperature by vaporisation of a liquid, said device comprising a hollow body made from a pressurE-resistant material, the interior of which is divided by a wall into two separate chambers, said wall preventing fluid flow between said chambers, one of said chambers being a reservoir chamber containing a vaporisable liquid and the other of said chambers being a combustion chamber containing a solid propellant, an ignition device for said propellant in said combustion chamber, means forming a gas-liquid mixing chamber adjacent said two chambers, first orifice means in the wall of said reservoir chamber and extending from said reservoir chamber to said mixing chamber, second orifice means extending from said combustion chamber to said mixing chamber to permit the flow of combustion gases from said combustion chamber directly into said mixing chamber, said second orifice means being in a direction perpendicular to the flow of gases before the gases enter therein and also perpendicular to the flow of liquid, said liquid and said gases traveling perpendicularly and forming an eddy flow within the mixing chamber, said wall which separates the two chambers comprising at least one movable portion which is movable by the gases in said combustion chamber to bring about a decrease in volume of the reservoir chamber under the action of the pressure of gases resulting from the combustion of said propellant in order to expel the liquid from said reservoir chamber through said orifice means in the wall thereof into said mixing chamber, whereby upon ignition of said propellant, combustion gases and said liquid separately flow into said mixing chamber and mixing of the combustion gases of the propellant with the liquid expelled from the reservoir and vaporisation of the said liquid in contact with the said gases causes instantaneous cooling of said gases.
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2. A device for effecting, in a very short time, a large release of cooled gases obtained by combustion of a propellant and cooling of the combustion gases to a moderate temperature by vaporisation of a liquid, said device comprising a hollow body made from a pressure-resistant material, the interior of which is divided by a wall into two separate chambers, said wall preventing fluid flow between said chambers, one of said chambers being a reservoir chamber containing a vaporisable liquid and the other of said chambers being a combustion chamber containing a solid propellant, and ignition device for said propellant in said combustion chamber, means forming a gas-liquid mixing chamber adjacent said two chambers, first orifice means in the wall of said reservoir chamber and extending from said reservoir chamber to said mixing chamber, second orifice means extending from said combustion chamber to said mixing chamber to permit the flow of combustion gases from said combustion chamber directly into said mixing chamber, said wall which separates the two chambers comprising at least one movable portion which is movable by the gases in said combustion chamber to bring about a decrease in volume of the reservoir chamber under the action of the pressure of gases resulting from the combustion of said propellant in order to expel the liquid from said reservoir chamber through said orifice means in the wall thereof into said mixing chamber, whereby upon ignition of said propellant, combustion gases and said liquid separately flow into said mixing chamber and mixing of the combustion gases of the propellant with the liquid expelled from the reservoir and vaporisation of the said liquid in contact with the said gases causes instantaneous cooling of said gases, wherein said hollow body is formed by two dish-like, half shells assembled one on the other to form a chamber therebetween and said wall is a separating membrane made from a deformable material and gripped between said shells, said membrane dividing the interior of the shell into said two chambers, and said mixing chamber being disposed adjacent the line of connection of said shells.
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3. A device for effecting, in a very short time, a large release of cooled gases obtained by combustion of a propEllant and cooling of the combustion gases to a moderate temperature by vaporisation of a liquid, said device comprising a hollow body made from a pressure-resistant material, the interior of which is divided by a wall into two separate chambers, said wall preventing fluid flow between said chambers, one of said chambers being a reservoir chamber containing a vaporisable liquid and the other of said chambers being a combustion chamber containing a solid propellant, an ignition device for said propellant in said combustion chamber, means forming a gas-liquid mixing chamber adjacent said two chambers, first orifice means in the wall of said reservoir chamber and extending from said reservoir chamber to said mixing chamber, second orifice means extending from said combustion chamber to said mixing chamber to permit the flow of combustion gases from said combustion chamber directly into said mixing chamber said wall which separates the two chambers comprising at least one movable portion which is movable by the gases in said combustion chamber to bring about a decrease in volume of the reservoir chamber under the action of the pressure of gases resulting from the combustion of said propellant in order to expel the liquid from said reservoir chamber through said orifice means in the wall thereof into said mixing chamber, whereby upon ignition of said propellant, combustion gases and said liquid separately flow into said mixing chamber and mixing of the combustion gases of the propellant with the liquid expelled from the reservoir and vaporisation of the said liquid in contact with the said gases causes instantaneous cooling of said gases, wherein said hollow body is cylindrical and said wall which divides the interior of said body into two separate chambers have a substantially cylindrical, hollow portion co-axial with said body and of an exterior diameter less than the interior diameter of said body to define an annular combustion chamber intermediate said body and said cylindrical portion and wherein said mixing chamber is at one end of said cylindrical portion and said movable portion of said wall is a piston slidably mounted in said cylindrical portion of said wall at the end thereof remote from said mixing chamber and is slidable axially of said cylindrical portion under the pressure of said gases.
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4. A device as claimed in claim 3, wherein said mixing chamber is formed by an extension of said cylindrical portion of said wall and is separated from said reservoir chamber by a partition transverse to the axis of said cylindrical portion, wherein said orifice means extending from said reservoir chamber to said mixing chamber is a plurality of injection nozzles extending through said partition, said mixing chamber being within and spaced from the interior wall of said body whereby said mixing chamber is at least partly surrounded by said combustion chamber and wherein said orifice means extending from said combustion chamber to said mixing chamber comprises a plurality of radially extending nozzles in the portion of the mixing chamber wall surrounded by said combustion chamber.
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5. A device as claimed in claim 4, wherein said injection nozzles are convergent.
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6. A device as claimed in claim 4, wherein said injection nozzles have anti-splash means as a part thereof and within said mixing chamber.
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7. A device as claimed in claim 3, wherein said hollow body is a substantially cylindrical monoblock hollow body closed at one end by a base pierced with diffusion slots and at its other end by a separate base, wherein said cylindrical portion is closed at the end thereof adjacent said pierced base by a partition spaced from said pierced base to form said mixing chamber therebetween, wherein said combustion chamber has at one end thereof an annular plate extending around said cylindrical portion and between said cylindrical portion and the interior wall of said body, said plate being spaced from said pierced base a distance greater than the spacing of said partition froM said pierced base to thereby provide an extension of said mixing chamber around said cylindrical portion, wherein said orifice means extending from said reservoir chamber to said mixing chamber comprises a plurality of radially extending orifices in said cylindrical portion intermediate said partition and said plate and wherein said orifice means extending from said combustion chamber to said mixing chamber comprises a plurality of orifices extending through said annular plate.
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8. A device as claimed in claim 7, wherein the opposite end of said cylindrical portion is closed by a piston slidably mounted therein and spaced from at least a portion of said separate base to permit gases from said combustion chamber to enter therebetween.
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9. A device as claimed in claim 3, wherein said cylindrical portion is made of a material deformable by the gases in said combustion chamber.
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10. A device as claimed in claim 3, wherein the solid propellant is a powder selected from the group of solid propellants consisting of a double base powder in hollow strands, a corrugated cardboard powder, a lamellar powder and a low combustion time powder, the specific flow of which is less than 1,500-2,000g/s/cm2 and the gas generating characteristics of which vary in dependence upon the initial firing temperature.
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11. A device as claimed in claim 3, wherein the ignition device comprises a toric ignitor.
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12. A device as claimed in claim 3, wherein the vaporisable liquid is selected from the group consisting of water and mixture of water and a lower alkanol, a mixture of water and a diol, a water methanol mixture, a water glycol mixture, and an aqueous solution of calcium chloride.
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13. A device as claimed in claim 3, wherein said liquid is enclosed in a hermetically sealed enclosure made from easily puncturable plastics material, said enclosure being received in said reservoir chamber.
Specification