Showing papers on "Propellant published in 1990"

Dental handpiece assembly

Abstract: A gas driven medical or dental handpiece assembly of the type having a turbine driven dental tool. A sterile coolant supply is usable with the handpiece to provide liquid fluid under pressure to irriagate the patient site and cool the dental tool. The coolant fluid is derived from a cartridge connected to the handpiece. The cartridge is replaced for each patient. The cartridge is divided by a flexible diaphragm into a propellant chamber and a liquid chamber. Initially the liquid chamber is full and the propellant chamber is empty with virtually a volume of zero. A propellant gas under pressure is introduced into the propellant chamber of the cartridge to displace the diaphragm and move the liquid through a fluid conduit to the tip of the handpiece. The propellant is derived from a portion of the compressed gas used to drive the turbine. Another portion of the compressed gas is diverted to a chip air conduit of the handpiece. The handpiece assembly eliminates the use of the conventional common water supply as irrigant or coolant fluid. Use of the removeable fluid cartridge allows sterilization of the entire handpiece eliminating much of the risk of cross contamination between patients.

Gas inflator apparatus

Abstract: A gas inflator apparatus for deploying inflatable devices, particularly automobile air bags, which provides an initial flow rate of gas into the air bag, followed by a delayed maximum flow rate to fully deploy the air bag, the apparatus particularly having the capability to program the delay by monitoring certain environmental conditions, namely pressure, and additionally providing temperature compensation for variations in ambient conditions, all of which optimize performance of the gas inflator apparatus over a wider range of operating conditions. A single electrical signal is sent to the gas inflator apparatus upon the sensing of an impact. The signal actuates an electro-explosive device which allows stored gas in the gas inflator apparatus to begin flowing into the air bag. Mechanical elements monitor the differential pressure between a pressure related to the pressure in the housing which stores the gas and a reference pressure. Upon achievement of a programmed differential pressure, the mechanical elements ignite a gas generator propellant, the combustion of which augments the flow rate into the air bag to ensure full inflation thereof.

Foamable aerosol preparation

Abstract: A foamable aerosol preparation for use as the base of cosmetics, quasi drugs, drugs, and so forth, which comprises 0.1 to 5 w/v % of a surfactant, 0.05 to 10 w/v % of a lower alcohol and/or a glycol, 3 to 25 w/v % of water, and 60 to 95 w/v % of n-butane gas. Despite of the use of n-butane gas as the propellant, this preparation foams very well and is excellent in cracking sound when applied to skin. Furthermore it is particularly useful from the viewpoint of environmental protection, because it is free from the problem of the depletion of the ozonosphere by virtue of the use of a liquefied petroleum gas as the propellant instead of fluorocarbon gas heretofore used.

Projectile propellant apparatus and method

Abstract: A projectile propellant device is adapted to supply a compressed gas from a compressed gas container for providing the propulsion force for a projectile or for providing the operating force for a gas powered device. The propellant device includes a gas container containing a volume of gas at sufficient pressure for applying a desired force upon release, and a compressed gas releasing structure for producing a release opening in the compressed gas container in response to the detonation of a pyrotechnic material. The release opening releases the compressed gas for applying the desired force, such as a propulsion force to propel a projectile. The gas releasing structure preferably includes a pyrotechnic charge device and a puncturing device both mounted within a suitable device housing along with the gas container. The pyrotechnic charge is adapted to be detonated preferably through an electrical discharge to force the puncture device into the compressed gas container to puncture or otherwise form the gas release opening to release the gas from the gas container.

Method and mechanical, electrical, or electronic apparatus for dispensing, issuing, or diffusing medicines, fragrances or other liquid or visous substances in the liquid phase or in the gaseous phase

Abstract: A method of dispensing, issuing, or diffusing a liquid (volatile or otherwise) without using a propellant gas, the liquid being a perfume, a cosmetic, an insecticide, or a medicine, for example. The method consists in using a pump type spray head where a liquid is sprayed by being expelled under pressure through a nozzle, and being characterized by the use of a mechanical device during the expulsion stage for obtaining an instantaneous pressure which causes a dose or a spray to be delivered comparable to an aerosol of the type obtained when using a compressed or liquefied propellant gas i.e. an aerosol in which the particles of divided liquid are not greater than 45 microns in size in the liquid phase, and are less than 1 micron in the gas phase, after spraying has occurred, and without spoiling the sprayed substances. The invention also relates to an exclusive or protective system which is personalized by encoding-decoding means that may be mechanical, electronic, or both, assisted by means of an audio-electronic speech synthesis system.

Water based two phase aerosol hairsprays

Abstract: This invention presents novel two-phase hair-fixing aerosol systems which are aqueous-based. The systems, which utilize dimethyl ether as a propellant (and also a solvent, as needed), can be shaken to form a semi-stable emulsion or mixture which is stable for a time sufficient for spraying, and are compatible with a wide variety of hair-fixing resins.

Gas generator with improved ignition assembly

Abstract: A gas generating type tool includes a propellant charge having an axially extending passage receiving therein an ignition tube containing a quantity of easily ignited, fast burning powder. The propellant and ignition tube are separately handled and/or transported until ready to run into the well. The tube slides easily into the propellant passage. The propellant passage is at least about 12% larger in cross-section than the ignition tube and not more than about 55% larger in cross-section. In circular cross-sections, the propellant passage is at least about 6% greater in diameter and not more than about 25% greater in diameter.

Launch vehicle with reconfigurable interstage propellant manifolding and solid rocket boosters

Abstract: A launch vehicle having one or more high thrust solid propellant boosters and two or more liquid propellant stages all configured to burn in parallel and having an interstage propellant manifolding system between the parallel liquid burning stages. Preferably, existing U.S. launch vehicle stages may be employed as the parallel burning stages. An additional liquid stage burning in series with the lower stages may also be employed. The interstage propellant manifolding between the liquid burning stages allows the central vehicle core to be stabilized against high altitude wind loads and further provides increased performance to the launch vehicle. Additionally, the interstage propellant transfer manifold is equipped with a plurality of electromechanical valves to allow reconfiguration of the propellant flow in real time in the event of a stage failure, thereby providing significantly increased vehicle reliability.

Prediction of self-pressurization rate of cryogenic propellant tankage

Abstract: The SOLA-ECLIPSE code is being developed to enable prediction of the behavior of cryogenic propellants in spacecraft tankage. A brief description of the formulations used for modeling heat transfer and for determining the thermodynamic state is presented. Code performance is verified through comparison to experimental data for the self-pressurization of scale-model liquid hydrogen tanks. SOLA-ECLIPSE is used to examine the effect of initial subcooling of the liquid phase on the self-pressurization rate of an on-orbit full-scale liquid hydrogen tank typical for a chemical-propulsion orbit transfer vehicle. The computational predictions show that even small amounts of subcooling will significantly decrease the self-pressurization rate. Further, if the cooling is provided by a thermodynamic vent system, it is concluded that small levels of subcooling will maximize propellant conservation.

Encapsulated propellant grain composition, method of preparation, article fabricated therefrom and method of fabrication

Abstract: A propellant grain composition for use in solid fuel rocket engines comprises a first reactant component consisting of an oxidizer. A polymeric barrier coating encapsulates the first reactant component and a second reactant component comprising a reducer fuel reactable with the oxidizer is coated thereon, A final polymeric coating is placed over the entire propellant grain to yield a unitary metal fuel-oxidizer propellant grain structure for use as a solid rocket fuel.

Therapeutic aerosol formulations

Abstract: Disclosed are self-propelled therapeutic aerosol compositions, and a process for the preparation thereof, comprising a micronized, water soluble, propellant insoluble homogeneous complex of a drug and an extender suspended in a propellant mixture.

Powder discharge apparatus

Abstract: An apparatus for the discharge of powder by a fluidic propellant is suitable for use as a fire extinguisher, the apparatus including a container wherein powder and propellant is pressurized prior to use of the apparatus. Discharge of the powder and the propellant from the container is accomplished by means of a diaphragm in a wall of the container, there being a gas generator contained within a well of the container for providing an overpressure which, in combination with the pressure to which the propellant has been charged, fractures the diaphragm. Thereupon, the propellant and the powder exits the container in a homogeneous stream. The overpressure is less than approximately 30 percent, preferably 20 percent of the pressure to which the propellant and the powder are subjected during a charging of the container with the powder and the propellant. The charge pressure is in the range of 400-600 p.s.i. so as to be many times greater than the pressure of an environment external to the container. A battery operated circuit may be connected between a fire sensor and the gas generator for activation of the generator in a modular self-contained form of fire extinguisher.

Liquid propellant supply device for spacecraft adapted to predict the end of its service life

Abstract: A liquid propellant supply device for satellites comprises an inlet pipe connected to a source of pressurizing gas, an outlet pipe connected to a propellant distribution manifold and a main storage tank connected at an inlet orifice to the inlet pipe and at an outlet orifice to the outlet pipe. The main storage tank contains a capillary action propellant retention device between the interior of the main storage tank and the outlet pipe. The device further comprises, on the outlet pipe, starting from the main storage tank, a gas test device adapted to detect the presence in the outlet pipe of a significant quantity of gas followed by an auxiliary storage tank substantially smaller than the main storage tank and including a second capillary action propellant retention device separating the interior of the auxiliary storage tank and the distribution manifold.

Gas storage and dispensing system

Abstract: Systems for storing and dispensing gases. The gas storage systems are two-phase gas/solid or gas/liquid, or three-phase gas/liquid/solid, functioning by reversible sorption. In gas storage systems having a solid phase, use is made of a polymeric material, preferably a hydrogel, having microvoids functioning as interstitial stores for gas. Reversible gas sorption in the microporous polymer is improved by treatment with a swelling promoter. The stored gas may be a propellant, and reversible sorption propellant storage may be used in all types of pressure pack dispenser. Cryogenic techniques facilitate preparation of propellant systems with standardized parameters. The invention enables use of safe and environmentally benign gases as propellants.

Pressure relief device for solid propellant motors subjected to high external temperatures

Abstract: A rocket motor that has a solid propellant with closure means that is secd to the rocket motor housing by heat responsive means that melts before the solid propellant ignites to prevent the rocket motor from becoming propulsive when subjected to excessive external heat sufficient to cause the rocket propellant to ignite.

Solar thermal propulsion engine

Abstract: The invention is directed to a solar thermal propulsion engine which comprises: (a) an ogive solar collection cavity with inner and outer walls having therebetween a heat exchange medium which can pass and heat a propellant fluid, and having its highest temperature deep within the cavity, and (b) a nozzle attached to and communicating with the heat exchange medium through which the heated propellant fluid can be passed to create thrust. In addition, this invention is directed to a solar thermal propulsion engine which comprises. (a) a heat exchanger having a geometry such that it has inner and outer walls having therebetween an open cell foam heat exchange medium through which a propellant can pass with tubulence, wherein solar radiation can heat the inner wall and the open foam heat exchange medium to, in turn, heat the propellant, and (b) a nozzle attached to and communicating with the open cell foam heat exchange medium through which the heated propellant fluid can be passed to creat thrust. In a preferred embodiment, the heat exchange medium of the ogive solar collection cavity is the open cell foam heat exchange medium. In a more preferred embodiment, such a preferred solar thermal propulsion engine further includes a paraboloid solar concentrator having the foam heat exchange medium in its walls.

Low thrust rocket test facility

Abstract: A low thrust chemical rocket test facility has recently become operational at the NASA-Lewis The new facility is used to conduct both long duration and performance tests at altitude over a thruster's operating envelope using hydrogen and oxygen gas for propellants The facility provides experimental support for a broad range of objectives, including fundamental modeling of fluids and combustion phenomena, the evaluation of thruster components, and life testing of full rocket designs The major mechanical and electrical systems are described along with aspects of the various optical diagnostics available in the test cell The electrical and mechanical systems are designed for low down time between tests and low staffing requirements for test operations Initial results are also presented which illustrate the various capabilities of the cell

Solid propellant canister loaded multiple pulsed or staged rocket

Abstract: A multi-pulse or multi-stage canister loaded solid propellant rocket motor. The canisters are prepared separately and loaded with solid propellant whereby the scrape rate may be reduced after which they are installed in a monolithic case which affords stiffness continuity over the length of the rocket motor to prevent guidance system upsetting free play. In order to reduce the complexity of installation of the membrane seal assembly for each pulse, the bulkhead therefor is manufactured integral with the case of the respective canister and becomes the forward closure thereof. For the multi-stage rocket motor, the monolithic case may be stepped and tapered, and the stages severable therefrom as they burn out by primer cord.

Aerosol container and propellant

Abstract: The invention relates to a compressed gas container, in particular an aerosol container, containing 2-hydroheptafluoropropane (F 227) liquefied under pressure or a mixture thereof with propane and/or n-butane and/or isobutane and/or dimethyl ether and/or 1,1-difluoroethane liquefied under pressure. The invention also relates to a propellant for aerosols, consisting of F 227 or its stated mixtures.

High performance, low cost solid propellant compositions producing halogen free exhaust

Abstract: High performance solid propellant compositions producing halogen-free exhaust products comprised of Ammonium Nitrate and powdered magnesium and optionally containing polyoxypropylene glycol as a binder.

Experiments on a repetitively pulsed electrothermal thruster

Abstract: This paper presents experimental results from an investigation of a pulsed electrothermal (PET) thruster using water propellant. The PET thruster is operated on a calibrated thrust stand, and produces a thrust to power ratio of T/P = 0.07 + or - 0.01 N/kW. The discharge conditions are inferred from a numerical model which predicts pressure and temperature levels of 300-500 atm and 20,000 K, respectively. These values in turn correctly predict the measured values of impulse bit and discharge resistance. The inferred ideal exhaust velocity from these conditions is 17 km/sec, but the injection of water propellant produces a test tank background pressure of 10-20 Torr, which reduces the exhaust velocity to 14 km/sec. This value corresponds to a thrust efficiency of 54 + or - 7 percent when all experimental errors are taken into account.

Nonintrusive ultrasonic low-liquid-level sensor

Abstract: A nonintrusive ultrasonic sensor system for monitoring the fuel level in the liquid propellant tanks of space launch vehicles has been developed and tested. The system consists of the monitoring sensor, which is mounted on the wall of the propellant tank, and an accompanying electronic package, which drives the sensor and processes the signals. The operating principle is based on the acoustic impedance variation caused by the presence (or absence) of a liquid above (or below) where the sensor is mounted on the tank

High energy-density liquid rocket fuel performance

Abstract: A fuel performance database of liquid hydrocarbons and aluminum-hydrocarbon fuels was compiled using engine parametrics from the Space Transportation Engine Program as a baseline. Propellant performance parameters are introduced. General hydrocarbon fuel performance trends are discussed with respect to hydrogen-to-carbon ratio and heat of formation. Aluminum-hydrocarbon fuel performance is discussed with respect to aluminum metal loading. Hydrocarbon and aluminum-hydrocarbon fuel performance is presented with respect to fuel density, specific impulse, and propellant density specific impulse.

Arrangement for an airbag gas generator

Abstract: An airbag gas generator is disclosed which includes a propellant chamber and a filter chamber arranged adjacent the propellant chamber for filtering flow of airbag propellant gas therethrough on its path to an airbag cushion. The filter chamber is provided with a plurality of alternative gas flow paths therethrough which have respective different filter resistances. Temperature dependent change-over devices are provided for controlling the flow of gas through the respective alternative gas flow paths in the filter chamber as a function of the ambient temperature at the generator.

Medium power arcjet thruster experiments

Abstract: Experimental results on the electrothermal behavior and operating performance of water-cooled laboratory model arcjet thrusters using a variety of propellants in the range of 5-50 kW are reported. The highest voltage and specific impulse are attained with hydrogen propellant and the lowest with argon propellant; intermediate results are obtained with nitrogen and a mixture of hydrogen and nitrogen. The highest cathode erosion rate is measured with argon while the lowest is associated with hydrogen.

Propellant utilization system

Abstract: The invention is a propellant utilization system for flight vehicles operating in both the subsonic and supersonic speed ranges. In particular, the invention uses steam and water produced in the system to replace hydrogen as a coolant and for power generation. It also provides for the utilization or oxygen obtained from air captured by the air inlet instead of oxygen stored in the vehicle.

High-performance dual-mode integral propulsion system

Abstract: A propulsion system in which pure hydrazine is used as the fuel for both a bipropellant rocket engine for high-thrust performance and in multiple monopropellant thrusters for station keeping and attitude control functions. Use of a common fuel for both modes of operation significantly reduces propellant weight and inert propulsion system weight for any given mission requirements, and therefore increases the payload that can be delivered to and maintained in a desired orbit. Further, for station-keeping, the monopropellant thrusters can be augmented in performance by employing either electrothermal or additional direct chemical energy, arc jet operation, or force field acceleration, to provide increased specific impulse values up to 2,000 seconds or higher.