EP0208983B1 - Process and apparatus for the production of solid propellants - Google Patents

Process and apparatus for the production of solid propellants Download PDF

Info

Publication number
EP0208983B1
EP0208983B1 EP19860108926 EP86108926A EP0208983B1 EP 0208983 B1 EP0208983 B1 EP 0208983B1 EP 19860108926 EP19860108926 EP 19860108926 EP 86108926 A EP86108926 A EP 86108926A EP 0208983 B1 EP0208983 B1 EP 0208983B1
Authority
EP
European Patent Office
Prior art keywords
process according
prepolymers
propellants
kneading
propellant
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Expired
Application number
EP19860108926
Other languages
German (de)
French (fr)
Other versions
EP0208983A1 (en
Inventor
Wolfgang Dr. Klöhn
Hiltmar Dr. Schubert
Dieter Müller
Siegfried Eisele
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Fraunhofer Gesellschaft zur Forderung der Angewandten Forschung eV
Original Assignee
Fraunhofer Gesellschaft zur Forderung der Angewandten Forschung eV
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Fraunhofer Gesellschaft zur Forderung der Angewandten Forschung eV filed Critical Fraunhofer Gesellschaft zur Forderung der Angewandten Forschung eV
Publication of EP0208983A1 publication Critical patent/EP0208983A1/en
Application granted granted Critical
Publication of EP0208983B1 publication Critical patent/EP0208983B1/en
Expired legal-status Critical Current

Links

Images

Classifications

    • C—CHEMISTRY; METALLURGY
    • C06—EXPLOSIVES; MATCHES
    • C06B—EXPLOSIVES OR THERMIC COMPOSITIONS; MANUFACTURE THEREOF; USE OF SINGLE SUBSTANCES AS EXPLOSIVES
    • C06B45/00—Compositions or products which are defined by structure or arrangement of component of product
    • C06B45/04—Compositions or products which are defined by structure or arrangement of component of product comprising solid particles dispersed in solid solution or matrix not used for explosives where the matrix consists essentially of nitrated carbohydrates or a low molecular organic explosive
    • C06B45/06—Compositions or products which are defined by structure or arrangement of component of product comprising solid particles dispersed in solid solution or matrix not used for explosives where the matrix consists essentially of nitrated carbohydrates or a low molecular organic explosive the solid solution or matrix containing an organic component
    • C06B45/10—Compositions or products which are defined by structure or arrangement of component of product comprising solid particles dispersed in solid solution or matrix not used for explosives where the matrix consists essentially of nitrated carbohydrates or a low molecular organic explosive the solid solution or matrix containing an organic component the organic component containing a resin
    • C—CHEMISTRY; METALLURGY
    • C06—EXPLOSIVES; MATCHES
    • C06B—EXPLOSIVES OR THERMIC COMPOSITIONS; MANUFACTURE THEREOF; USE OF SINGLE SUBSTANCES AS EXPLOSIVES
    • C06B21/00—Apparatus or methods for working-up explosives, e.g. forming, cutting, drying
    • C06B21/0008—Compounding the ingredient
    • C—CHEMISTRY; METALLURGY
    • C06—EXPLOSIVES; MATCHES
    • C06B—EXPLOSIVES OR THERMIC COMPOSITIONS; MANUFACTURE THEREOF; USE OF SINGLE SUBSTANCES AS EXPLOSIVES
    • C06B21/00—Apparatus or methods for working-up explosives, e.g. forming, cutting, drying
    • C06B21/0033—Shaping the mixture
    • C06B21/0075—Shaping the mixture by extrusion

Definitions

  • the invention relates to a process for the production of solid fuels, e.g. Composite, ram jet fuels or the like, consisting of at least one powdered oxidizer, e.g. Ammonium perchlorate, a prepolymer binder as fuel, optionally other solid fuels and additives, such as plasticizers, stabilizers, combustion moderators, etc., by mixing the aforementioned components and shaping them into propellants with the addition of a hardener. Furthermore, the invention is directed to an apparatus for performing the method.
  • oxidizer e.g. Ammonium perchlorate
  • a prepolymer binder as fuel
  • additives such as plasticizers, stabilizers, combustion moderators, etc.
  • Composite solid fuels with ammonium perchlorate and aluminum as solids as well as liquid prepolymer binders, such as polybutadienes with terminal hydroxyl groups, are poured into molds or combustion chambers after the mixing process at elevated temperatures in a vacuum casting process.
  • diisocyanate hardeners By adding diisocyanate hardeners, the poured fuel masses are hardened into viscoelastic propellants. This propellant production process has proven itself extremely well for many standard solid fuels.
  • the burning rate can be increased to 8-10 times. At the same time, however, there is a strong increase in the viscosity of the fuel mass, so that it can no longer be poured out.
  • Another prerequisite for achieving good pourability of the ready-mixed fuel is the selection of a prepolymer with the lowest possible initial viscosity.
  • An example of this can be seen in the product “Arco R 45M” ( R ) (product of Arco Chemical, New York), a polybutadiene prepolymer with terminal hydroxyl groups and a viscosity of 0.5 Pa.s at 30 ° C. Because of its low viscosity, this prepolymer has successfully established itself over comparable prepolymers.
  • binders with higher viscosities cannot be processed with the manufacturing process described, although the fuels cured with them would show interesting mechanical properties.
  • a polybutadiene-acrylonitrile prepolymer with terminal hydroxyl groups which has an acrylonitrile content of 17% and an initial viscosity of 140 Pa.s at 27 ° C.
  • These prepolymers would be excellently suited as binders for fuels, since the existing nitrile groups mediate excellent adhesive properties between the polymer binder and the solid particle.
  • these binders would not be suitable for processing using the vacuum casting process.
  • Further examples are the polybutadiene-acrylonitrile prepolymers with terminal carboxyl groups and with acrylonitrile contents between 10% and 26%, the viscosities of which vary between 60 and 570 Pa.s.
  • tough fuels is the fuels for ramjet drives based on boron.
  • the boron used has grain sizes in the range of ⁇ 1 ⁇ m and can therefore only be processed in low concentrations in the fuel due to the pourability limit. These difficulties have been avoided by using boron in granular form. So far, this solution has not been satisfactory either. This method also fails if the boron content is high.
  • the invention has for its object to provide a method and a device intended for its implementation, by means of which fuel mixtures can be processed into solid propellants, in which the solid starting components have a small grain size and / or the prepolymer binders have high viscosity.
  • this object is achieved according to the invention in that, for processing non-pourable fuel mixtures with a viscosity of> 1000 Pa.s, the components are mixed in a kneader under vacuum, the hardener is added to the mixture with further mixing and the finished mixture is extruded directly from the kneader into a fuel mold against back pressure.
  • the high viscosity of the fuel mixture allows the use of both fine and extremely fine grains of the solid starting components, e.g. the oxidizers such as ammonium perchlorate, or any solid fuels such as aluminum, boron or the like, as well as highly viscous binder types with improved mechanical properties.
  • the solids are intensively homogenized with the viscous prepolymers, whereby the mixing can take place at an elevated temperature. Mixing under vacuum on the one hand reduces the safety risk, on the other hand the pasty to pasty becomes Mass constantly vented.
  • the homogenized mixture with the hardener is pressed directly out of the kneader and pressed in batches into the fuel mold, in order to improve the form filling and to avoid air pockets, pressing against a suitably high counterpressure, which degrades as the mold is gradually filled. It can be used to produce composite fuels with a high proportion of ultra-fine oxidizer, such as ammonium perchlorate, as well as ramjet fuels with high, finely dispersed boron concentrations.
  • ultra-fine oxidizer such as ammonium perchlorate
  • the invention proposes a device which is distinguished by a horizontal kneader with a kneading trough which can be connected to a vacuum and horizontally arranged, intermeshing kneading blades, a discharge screw arranged at the bottom of the kneading trough and a propellant mold connected to its outlet, the mold volume of which Starting position is approximately zero and can be increased to the desired mold volume under the effect of the discharge pressure of the discharge screw and while maintaining a counter pressure.
  • the fuel components are therefore processed in batches in a closed system.
  • the fact that the propellant mold releases its mold volume only gradually when it is discharged results in an absolutely void-free molded body. Homogenization is particularly good when the kneading blades rotate in opposite directions and at different speeds.
  • the discharge screw rotates in the opposite direction of rotation during the filling of the kneader and during the kneading process with the discharge movement.
  • This design prevents the fuel components from getting into the discharge screw during the preparation of the mixture.
  • the discharge screw forms the closure of the kneading trough.
  • the device used in the tests had a kneading trough of 7 liters of useful content with two horizontally arranged kneading blades, which interlock deeply, strip each other and rotate at a speed ratio of 2: 1. They cause high friction in the kneaded material, which causes an intensive homogenization of the solids with the liquid prepolymers.
  • the kneading trough has a double jacket for heating with water during the kneading process.
  • the kneader is set up for operation in vacuum, which is generated by a rotary vane pump via connections on the trough cover.
  • the kneading paddles are driven hydrostatically with a radial piston motor with an infinitely variable speed from 0 to 40 min- 1 .
  • the viscous fuel paste gets into the discharge screw, which is connected via a tube to a combustion chamber that serves as a mold.
  • the speed of the discharge screw with a progressive gradient can also be continuously adjusted from 0 to 20 min- 1 .
  • the control pumps for driving the radial piston motors for kneading blades and discharge screw can be accommodated in a separate room.
  • This example describes the procedure for the production of fuels and the filling in combustion chambers.
  • a premix of the binder with the plasticizer, stabilizer, wetting agent, adhesion promoter, combustion moderator and aluminum is introduced and kneaded into the mixer at 50 ° C.
  • kneading takes about 1 hour until the solids are evenly coated with the binder and homogenized.
  • the vacuum is slowly increased to approx. 10 mbar via a control loop in order to remove the air from the kneaded material.
  • the vacuum is released and the hardener is added to the running machine via a storage hopper. Mixing in the hardener requires a further 20 minutes, while the vacuum is increased again to 10 mbar.
  • the finished mixed fuel paste is introduced into the screw conveyor after reversing the direction of rotation.
  • a hydraulically operated valve At the outlet of the screw conveyor there is a hydraulically operated valve and then a flanged combustion chamber or propellant.
  • the valve When the valve is opened, the mass of fuel can be extruded into the isolated combustion chamber against a brake cylinder.
  • the fuel that is conveyed into the mold pushes the piston out and replenishes the chamber volume. In this way, the fuel mass can be distributed very evenly.
  • a ramjet fuel of the following composition was produced and extruded in the same way:
  • the device has a kneader 1 with a kneading trough 2 and a lid 3.
  • the kneading trough 2 can be connected via a line 4 to a vacuum pump and can be aerated via a valve 5.
  • two shafts 6 are arranged side by side, which are equipped with kneading blades 7 in such a way that the kneading blades engage deeply with one another on adjacent shafts.
  • the kneader shaft 6 is guided to the outside at 8 and coupled to a drive, not shown.
  • a discharge screw 9 is arranged directly above the bottom of the kneading trough 2, which is led out on one side of the kneading trough and coupled at 10 to a drive (not shown). This drive is reversible.
  • a preferably cylindrical housing 11 is flanged to the kneading trough 2, into which the discharge screw 9 protrudes.
  • the housing 11 has a molding head 12 at its end.
  • a propellant charge form 13 is slidably mounted on the forming head 12 or a part of the screw housing 11.
  • the propellant charge form 13 is connected via a piston rod 14 to the piston 15 of a pneumatic cylinder 16, which in turn is connected to a compressed air shaft, not shown, via a pressure regulator 17.
  • the connection to the vacuum pump 4 is opened.
  • the kneading blades 7 on the shafts 6 arranged in pairs ensure intensive and kneading mixing of the components.
  • the discharge screw 9 rotates in the opposite direction, so that the mixture is pushed back into the kneader. If sufficient homogenization of the material is achieved, the drive at 10 is reversed when the kneading blades 7 continue to run, so that the discharge screw 9 rotates in the opposite direction and the mixture is discharged into the housing 11 and through the shaped piece 12 into the propellant mold 13.
  • the propellant form is designed as a cylinder closed on one side, on the bottom 18 of which the piston rod 14 engages with a head 19 tose.
  • the shape can directly form the insulation shell of a finished propellant charge.
  • the propellant charge form 13 can also be designed as a cylinder which is open on both sides and can be closed at one end by a displaceable base on which the piston rod then engages. If necessary, the pressure piece 19 can also form this displaceable base.
  • This design gives in particular the possibility of pushing the propellant out of the mold again by means of the base, or to subsequently close the open cylinder by another.

Description

Die Erfindung betrifft ein Verfahren zur Herstellung von Festtreibstoffen, z.B. Composite-, Staustrahltreibstoffe oder dgl., bestehend aus wenigstens einem pulverförmigen Oxidator, z.B. Ammoniumperchlorat, einem Prepolymer-Binder als Brennstoff, gegebenenfalls weiteren festen Brennstoffen und Additiven, wie Weichmacher, Stabilisatoren, Abbrandmoderatoren etc, indem die vorgenannten Komponenten gemischt und unter Zusatz eines Härters zu Treibsätzen geformt werden. Ferner ist die Erfindung auf eine Vorrichtung zur Durchführung des Verfahrens gerichtet.The invention relates to a process for the production of solid fuels, e.g. Composite, ram jet fuels or the like, consisting of at least one powdered oxidizer, e.g. Ammonium perchlorate, a prepolymer binder as fuel, optionally other solid fuels and additives, such as plasticizers, stabilizers, combustion moderators, etc., by mixing the aforementioned components and shaping them into propellants with the addition of a hardener. Furthermore, the invention is directed to an apparatus for performing the method.

Composite-Festtreibstoffe mit Ammoniumperchlorat und Aluminium als Feststoffen sowie flüssigen Prepolymer-Bindern, wie Polybutadienen mit endständigen Hydroxylgruppen, werden nach dem Mischvorgang bei erhöhten Temperaturen in einem Vakuum-Gießverfahren in Formen oder Brennkammern vergossen. Durch Zugabe von Diisocyanat-Härtern werden die vergossenen Treibstoffmassen zu viskoelastischen Treibsätzen ausgehärtet. Dieses Treibsatz-Herstellungsverfahren hat sich für viele Standard-Festtreibstoffe ausgezeichnet bewährt.Composite solid fuels with ammonium perchlorate and aluminum as solids as well as liquid prepolymer binders, such as polybutadienes with terminal hydroxyl groups, are poured into molds or combustion chambers after the mixing process at elevated temperatures in a vacuum casting process. By adding diisocyanate hardeners, the poured fuel masses are hardened into viscoelastic propellants. This propellant production process has proven itself extremely well for many standard solid fuels.

Als Voraussetzung für das Vakuum-Gießverfahren müssen allerdings Treibstoffmassen mit Viskositäten von ca. 200 bis 1000 Pa.s vorliegen, damit die zu vergießenden Massen aus dem Vorratsbehälter vollständig in die Gießformen oder Brennkammern ausfließen und sich noch einwandfrei verteilen können. Man kann die Verarbeitung von zäh fließenden Treibstoffen auch dadurch erleichtern, daß man mittels eines auf dem Vorratsbehälter aufliegenden Deckels den Treibstoff pneumatisch oder hydraulisch in die Brennkammer hineindrückt und durch Vibration der oft thixotropen Massen eine gleichmäßige Verteilung verursacht.As a prerequisite for the vacuum casting process, however, fuel masses with viscosities of approx. 200 to 1000 Pa.s must be available so that the masses to be poured flow out of the storage container completely into the molds or combustion chambers and can still be distributed perfectly. The processing of viscous flowing fuels can also be facilitated by pneumatically or hydraulically pushing the fuel into the combustion chamber by means of a cover resting on the storage container and by uniform vibration caused by the often thixotropic masses.

Diese Arbeitsweise führt in zahlreichen Fällen zu befriedigenden Ergebnissen bei Treibstoffen mit Feststoffanteilen von 80% bis 92%. Die erforderliche Gießfähigkeit kann aber nur dann verwirklicht werden, wenn die Feststoff-Anteile in bestimmten Ausfallkörnungen vorliegen. Von der mittleren Korngröße des Ammoniumperchlorats sind nun aber in hohem Maß die Abbrandgeschwindigkeit und andere ballistische Eigenschaften des Treibstoffs abhängig (US-A-3 954 526).In many cases, this procedure leads to satisfactory results for fuels with solids contents of 80% to 92%. However, the required pourability can only be achieved if the solids content is present in certain grain sizes. However, the burning rate and other ballistic properties of the fuel are highly dependent on the average grain size of the ammonium perchlorate (US Pat. No. 3,954,526).

Wenn z.B. die mittlere Korngröße des Ammoniumperchlorats von 200 J.l.m auf 2 µm reduziert wird, kann die Abbrandgeschwindigkeit auf 8-10fache Werte gesteigert werden. Damit ist aber zugleich ein starker Anstieg der Viskosität der Treibstoffmasse verknüpft, so daß diese sich nicht mehr vergießen läßt.If e.g. If the average grain size of the ammonium perchlorate is reduced from 200 J.l.m to 2 µm, the burning rate can be increased to 8-10 times. At the same time, however, there is a strong increase in the viscosity of the fuel mass, so that it can no longer be poured out.

Eine weitere Voraussetzung für die Erzielung einer guten Gießfähigkeit des fertig gemischten Treibstoffs ist die Auswahl eines Prepolymers mit möglichst niedriger Ausgangsviskosität. Ein Beispiel hierfür kann in dem Produkt «Arco R 45M»(R) (Erzeugnis der Arco Chemical, New York), einem Polybutadien-Prepolymer mit endständigen Hydroxylgruppen mit einer Viskosität von 0,5 Pa.s bei 30°C gesehen werden. Wegen seiner niedrigen Viskosität hat sich dieses Prepolymer gegenüber vergleichbaren Prepolymeren erfolgreich durchsetzen können.Another prerequisite for achieving good pourability of the ready-mixed fuel is the selection of a prepolymer with the lowest possible initial viscosity. An example of this can be seen in the product “Arco R 45M” ( R ) (product of Arco Chemical, New York), a polybutadiene prepolymer with terminal hydroxyl groups and a viscosity of 0.5 Pa.s at 30 ° C. Because of its low viscosity, this prepolymer has successfully established itself over comparable prepolymers.

Andere Bindertypen mit höheren Viskositäten lassen sich mit dem beschriebenen Herstellungsverfahren nicht verarbeiten, obwohl die damit ausgehärteten Treibstoffe interessante mechanische Eigenschaften zeigen würden. Als Beispiel sei auf ein Polybutadien-Acrylnitril-Prepolymer mit endständigen Hydroxylgruppen hingewiesen, das einen Acrylnitrilgehalt von 17% und eine Ausgangsviskosität von 140 Pa.s bei 27°C aufweist. Diese Prepolymere würden sich als Binder für Treibstoffe hervorragend eignen, da über die vorhandenen Nitrilgruppen vorzügliche Hafteigenschaften zwischen dem Polymer-Binder und dem Feststoffkorn vermittelt werden. Für die Verarbeitung nach dem Vakuum-Gießverfahren wären diese Binder aber nicht geeignet. Weitere Beispiele sind die Polybutadien Acrylnitril-Prepolymere mit endständigen Carboxylgruppen und mit Acrylnitrilgehalten zwischen 10% und 26%, deren Viskositäten zwischen 60 und 570 Pa.s variieren.Other types of binders with higher viscosities cannot be processed with the manufacturing process described, although the fuels cured with them would show interesting mechanical properties. As an example, reference is made to a polybutadiene-acrylonitrile prepolymer with terminal hydroxyl groups, which has an acrylonitrile content of 17% and an initial viscosity of 140 Pa.s at 27 ° C. These prepolymers would be excellently suited as binders for fuels, since the existing nitrile groups mediate excellent adhesive properties between the polymer binder and the solid particle. However, these binders would not be suitable for processing using the vacuum casting process. Further examples are the polybutadiene-acrylonitrile prepolymers with terminal carboxyl groups and with acrylonitrile contents between 10% and 26%, the viscosities of which vary between 60 and 570 Pa.s.

Als weiteres Beispiel zäher Treibstoffe sei auf die Treibstoffe für Staustrahlantriebe auf Bor-Basis hingewiesen. Das zum Einsatz kommende Bor weist Korngrößen im Bereich < 1 µm auf und ist deshalb wegen der Gießfähigkeits-Grenze nur in niedrigen Konzentrationen im Treibstoff zu verarbeiten. Man hat diese Schwierigkeiten durch Einsatz des Bors in granulierter Form umgangen. Bis jetzt konnte diese Lösung aber auch nicht befriedigen. Bei hohen Bor-Anteilen versagt auch dieses Verfahren.Another example of tough fuels is the fuels for ramjet drives based on boron. The boron used has grain sizes in the range of <1 µm and can therefore only be processed in low concentrations in the fuel due to the pourability limit. These difficulties have been avoided by using boron in granular form. So far, this solution has not been satisfactory either. This method also fails if the boron content is high.

Die aufgeführten Beispiele machen deutlich, daß die Gießfähigkeit von Treibstoffmischungen an bestimmte Eigenschaften der Ausgangskomponenten gebunden ist und damit die Entwicklung von Treibstoffen mit speziellen ballistischen und mechanischen Eigenschaften und einer großen Abbrandgeschwindigkeit an ihrer mangelnden Verarbeitbarkeit scheitert.The examples given make it clear that the pourability of fuel mixtures is tied to certain properties of the starting components and that the development of fuels with special ballistic and mechanical properties and a high burn-up rate fails because of their poor processability.

Der Erfindung liegt die Aufgabe zugrunde, ein Verfahren und eine zu seiner Durchführung bestimmte Vorrichtung zu schaffen, mit deren Hilfe Treibstoffmischungen zu festen Treibsätzen verarbeitet werden können, bei denen die festen Ausgangskomponenten kleine Korngröße und/oder die Prepolymer-Binder hohe Viskosität aufweisen.The invention has for its object to provide a method and a device intended for its implementation, by means of which fuel mixtures can be processed into solid propellants, in which the solid starting components have a small grain size and / or the prepolymer binders have high viscosity.

Ausgehend von dem eingangs genannten Verfahren wird diese Aufgabe erfindungsgemäß dadurch gelöst, daß zur Verarbeitung von nicht gießfähigen Treibstoffmischungen mit einer Viskosität >, 1000 Pa.s die Komponenten in einem Kneter unter Vakuum gemischt, der Härter der Mischung unter weiterem Mischen zugegeben und die fertige Mischung unmittelbar aus dem Kneter in eine Treibstofform gegen einen Gegendruck extrudiert wird.Starting from the process mentioned at the outset, this object is achieved according to the invention in that, for processing non-pourable fuel mixtures with a viscosity of> 1000 Pa.s, the components are mixed in a kneader under vacuum, the hardener is added to the mixture with further mixing and the finished mixture is extruded directly from the kneader into a fuel mold against back pressure.

Die hohe Viskosität der Treibstoffmischung erlaubt den Einsatz sowohl feiner und feinster Körnungen der festen Ausgangskomponenten, z.B. der Oxidatoren, wie Ammoniumperchlorat, oder eventueller fester Brennstoffe, wie Aluminium, Bor oder dgl., als auch von hochviskosen Bindertypen mit verbesserten mechanischen Eigenschaften. Durch das Mischen im Kneter werden die Feststoffe mit den viskosen Prepolymeren intensiv homogenisiert, wobei das Mischen bei erhöhter Temperatur erfolgen kann. Das Mischen unter Vakuum vermindert einerseits das Sicherheitsrisiko, andererseits wird die pastöse bis teigige Masse ständig entlüftet. Die homogenisierte Mischung mit dem Härter wird unmittelbar aus dem Kneter herausgedrückt und satzweise in die Treibstofform gepreßt, wobei zur Verbesserung der Formfülligkeit und zur Vermeidung von Lufteinschlüssen das Auspressen gegen einen geeignet hohen Gegendruck erfolgt, der sich unter allmählichem Füllen der Form abbaut. Damit lassen sich Composite-Treibstoffe mit hohem Anteil an ultrafeinem Oxidator, z.B. Ammoniumperchlorat, wie auch Staustrahltreibstoffe mit hohen, feindispersen Borkonzentrationen herstellen.The high viscosity of the fuel mixture allows the use of both fine and extremely fine grains of the solid starting components, e.g. the oxidizers such as ammonium perchlorate, or any solid fuels such as aluminum, boron or the like, as well as highly viscous binder types with improved mechanical properties. By mixing in the kneader, the solids are intensively homogenized with the viscous prepolymers, whereby the mixing can take place at an elevated temperature. Mixing under vacuum on the one hand reduces the safety risk, on the other hand the pasty to pasty becomes Mass constantly vented. The homogenized mixture with the hardener is pressed directly out of the kneader and pressed in batches into the fuel mold, in order to improve the form filling and to avoid air pockets, pressing against a suitably high counterpressure, which degrades as the mold is gradually filled. It can be used to produce composite fuels with a high proportion of ultra-fine oxidizer, such as ammonium perchlorate, as well as ramjet fuels with high, finely dispersed boron concentrations.

Weitere Ausführungsbeispiele des erfindungsgemäßen Verfahrens sind in den Ansprüchen 2 bis 12 gekennzeichnet.Further exemplary embodiments of the method according to the invention are characterized in claims 2 to 12.

Zur Durchführung des Verfahrens schlägt die Erfindung eine Vorrichtung vor, die sich auszeichnet durch einen Horizontalkneter mit einem an Vakuum anschließbaren Knettrog und horizontal angeordneten, ineinander greifenden Knetschaufeln, eine am Boden des Knettrogs angeordnete Austragsschnecke und eine an deren Ausgang angeschlossene Treibsatzform, deren Formvolumen in der Ausgangslage annähernd null ist und unter Wirkung des Förderdrucks der Austragsschnecke sowie unter Aufrechterhaltung eines Gegendrucks bis zum gewünschten Formvolumen vergrößerbar ist.To carry out the method, the invention proposes a device which is distinguished by a horizontal kneader with a kneading trough which can be connected to a vacuum and horizontally arranged, intermeshing kneading blades, a discharge screw arranged at the bottom of the kneading trough and a propellant mold connected to its outlet, the mold volume of which Starting position is approximately zero and can be increased to the desired mold volume under the effect of the discharge pressure of the discharge screw and while maintaining a counter pressure.

Die Verarbeitung der Treibstoffkomponenten erfolgt somit chargenweise in einem geschlossenen System. Dadurch, daß die Treibsatzform erst beim Austragen ihr Formvolumen allmählich freigibt, ergibt sich ein absolut lunkerfreier Formkörper. Eine besonders gute Homogenisierung ergibt sich dann, wenn die Knetschaufeln gegenläufig und mit verschiedener Drehzahl umlaufen.The fuel components are therefore processed in batches in a closed system. The fact that the propellant mold releases its mold volume only gradually when it is discharged results in an absolutely void-free molded body. Homogenization is particularly good when the kneading blades rotate in opposite directions and at different speeds.

Gemäß einem bevorzugten Ausführungsbeispiel ist vorgesehen, daß die Austragsschnecke während des Befüllens des Kneters und während des Knetvorgangs mit der Austragsbewegung entgegengesetztem Drehsinn umläuft. Mit dieser Ausbildung wird verhindert, daß die Treibstoffkomponenten während der Herstellung der Mischung in die Austragsschnecke gelangen. Zugleich bildet die Austragsschnecke den Verschluß des Knettrogs.According to a preferred embodiment, it is provided that the discharge screw rotates in the opposite direction of rotation during the filling of the kneader and during the kneading process with the discharge movement. This design prevents the fuel components from getting into the discharge screw during the preparation of the mixture. At the same time, the discharge screw forms the closure of the kneading trough.

Die bei Versuchen verwendete Vorrichtung besaß einen Knettrog von 7 Litern Nutzinhalt mit zwei horizontal angeordneten Knetschaufeln, die tief ineinander greifen, sich gegenseitig abstreifen und in einem Drehzahl-Verhältnis von 2:1 umlaufen. Sie bewirken im Knetgut hohe Friktionen, die eine intensive Homogenisierung der Feststoffe mit den flüssigen Prepolymeren bewirken. Der Knettrog besitzt einen Doppelmantel zur Heizung mit Wasser während des Knetprozesses. Der Kneter ist zum betrieb im Vakuum eingerichtet, das über Anschlüsse am Trogdeckel von einer Drehschieberpumpe erzeugt wird. Der Antrieb der Knetschaufeln erfolgt hydrostatisch mit einem Radialkolbenmotor mit stufenlos einstellbarer Drehzahl von 0 bis 40 min-1.The device used in the tests had a kneading trough of 7 liters of useful content with two horizontally arranged kneading blades, which interlock deeply, strip each other and rotate at a speed ratio of 2: 1. They cause high friction in the kneaded material, which causes an intensive homogenization of the solids with the liquid prepolymers. The kneading trough has a double jacket for heating with water during the kneading process. The kneader is set up for operation in vacuum, which is generated by a rotary vane pump via connections on the trough cover. The kneading paddles are driven hydrostatically with a radial piston motor with an infinitely variable speed from 0 to 40 min- 1 .

Nach Beendigung des Mischvorgangs gelangt die zähe Treibstoffpaste in die Austragsschnecke, die über ein Rohr mit einer als Form dienenden Brennkammer verbunden ist. Die Drehzahl der Austragsschnecke mit progressiver Steigung kann ebenfalls von 0 bis 20 min-1 stufenlos eingestellt werden. Die Regelpumpen zum Antrieb der Radialkolbenmotore für Knetschaufeln und Austragsschnecke können in einem separaten Raum untergebracht werden.At the end of the mixing process, the viscous fuel paste gets into the discharge screw, which is connected via a tube to a combustion chamber that serves as a mold. The speed of the discharge screw with a progressive gradient can also be continuously adjusted from 0 to 20 min- 1 . The control pumps for driving the radial piston motors for kneading blades and discharge screw can be accommodated in a separate room.

Beispiel 1example 1

In diesem Beispiel ist die Verfahrensweise bei der Herstellung von Treibstoffen und das Einfüllen in Brennkammern beschrieben.

Figure imgb0001
This example describes the procedure for the production of fuels and the filling in combustion chambers.
Figure imgb0001

In den Mischer wird bei 50°C eine Vormischung des Binders mit dem Weichmacher, Stabilisator, Benetzungsmittel, Haftvermittler, Abbrandmoderator und Aluminium eingefüllt und geknetet. Nach Zugabe der beiden Ammoniumperchlorat-Sorten in mehreren Portionen wird ca. 1 Stunde geknetet, bis die Feststoffe gleichmäßig mit dem Binder überzogen und homogenisiert sind. Während dieser Zeit läuft die Austragsschnecke gegen ihre Förderrichtung um, damit kein Material in den Schneckenraum gelangt. Über einen Regelkreis wird das Vakuum langsam auf ca. 10 mbar gefahren, um die Luft aus dem Knetgut zu entfernen. Nach Beendigung des Knetvorgangs wird das Vakuum aufgehoben und über einen Vorratstrichter der Härter in die laufende Maschine zugegeben. Die Einmischung des Härters erfordert weitere 20 Minuten, während das Vakuum wieder auf 10 mbar erhöht wird. Die fertig gemischte Treibstoffpaste wird nach Umkehr der Drehrichtung in die Förderschnecke eingeführt.A premix of the binder with the plasticizer, stabilizer, wetting agent, adhesion promoter, combustion moderator and aluminum is introduced and kneaded into the mixer at 50 ° C. After adding the two types of ammonium perchlorate in several portions, kneading takes about 1 hour until the solids are evenly coated with the binder and homogenized. During this time, the discharge screw rotates in the opposite direction to ensure that no material gets into the screw chamber. The vacuum is slowly increased to approx. 10 mbar via a control loop in order to remove the air from the kneaded material. After the kneading process is complete, the vacuum is released and the hardener is added to the running machine via a storage hopper. Mixing in the hardener requires a further 20 minutes, while the vacuum is increased again to 10 mbar. The finished mixed fuel paste is introduced into the screw conveyor after reversing the direction of rotation.

Am Ausgang der Förderschnecke befindet sich ein hydraulisch zu betätigendes Ventil und anschließend eine angeflanschte Brennkammer oder Treibsatzform. Wenn das Ventil geöffnet wird, kann die Treibstoffmasse in die isolierte Brennkammer gegen einen Bremszylinder extrudiert werden. Durch den in die Form geförderten Treibstoff wird der Kolben herausgedrückt und das Kammervolumen aufgefüllt. Die Treibstoffmasse läßt sich auf diese Weise sehr gleichmäßig verteilen.At the outlet of the screw conveyor there is a hydraulically operated valve and then a flanged combustion chamber or propellant. When the valve is opened, the mass of fuel can be extruded into the isolated combustion chamber against a brake cylinder. The fuel that is conveyed into the mold pushes the piston out and replenishes the chamber volume. In this way, the fuel mass can be distributed very evenly.

Beispiel 2Example 2

In gleicher Weise wurde ein Staustrahl-Treibstoff der folgenden Zusammensetzung hergestellt und extrudiert:

Figure imgb0002
Figure imgb0003
 A ramjet fuel of the following composition was produced and extruded in the same way:
Figure imgb0002
Figure imgb0003

Nachstehend ist die Erfindung anhand eines in der Zeichnung im Längsschnitt wiedergegebenen Ausführungsbeispiels der Erfindung beschrieben.The invention is described below with reference to an embodiment of the invention shown in longitudinal section in the drawing.

Die Vorrichtung weist einen Kneter 1 mit einem Knettrog 2 und einem Deckel 3 auf. Der Knettrog 2 ist über eine Leitung 4 an eine Vakuumpumpe anschließbar und kann über ein Ventil 5 belüftet werden.The device has a kneader 1 with a kneading trough 2 and a lid 3. The kneading trough 2 can be connected via a line 4 to a vacuum pump and can be aerated via a valve 5.

In dem Knettrog 2 sind nebeneinander zwei Wellen 6 angeordnet, die mit Knetschaufeln 7 derart ausgestattet sind, daß die Knetschaufeln auf benachbarten Wellen tief ineinander eingreifen. Die Kneterwelle 6 ist bei 8 nach außen geführt und an einen nicht gezeigten Antrieb angekuppelt.In the kneading trough 2 two shafts 6 are arranged side by side, which are equipped with kneading blades 7 in such a way that the kneading blades engage deeply with one another on adjacent shafts. The kneader shaft 6 is guided to the outside at 8 and coupled to a drive, not shown.

Unmittelbar oberhalb des Bodens des Knettrogs 2 ist eine Austragschnecke 9 angeordnet, die an der einen Seite des Knettrogs herausgeführt und bei 10 an einen nicht gezeigten Antrieb angekuppelt ist. Dieser Antrieb ist reversierbar. An der gegenüberliegenden Seite ist an den Knettrog 2 ein vorzugsweise zylindrisches Gehäuse 11 angeflanscht, in das die Austragschnecke 9 hineinragt. Das gehäuse 11 weist an seinem Ende einen Formkopf 12 auf.A discharge screw 9 is arranged directly above the bottom of the kneading trough 2, which is led out on one side of the kneading trough and coupled at 10 to a drive (not shown). This drive is reversible. On the opposite side, a preferably cylindrical housing 11 is flanged to the kneading trough 2, into which the discharge screw 9 protrudes. The housing 11 has a molding head 12 at its end.

Auf den Formkopf 12 bzw einen Teil des Schneckengehäuses 11 ist eine Treibsatzform 13 verschiebbar aufgesetzt. Die Treibsatzform 13 ist über eine Kolbenstange 14 an den Kolben 15 eines Pneumatikzylinders 16 angeschlossen, der seinerseits über einen Druckregler 17 mit einer nicht gezeigten Druckluftwelle verbunden ist.A propellant charge form 13 is slidably mounted on the forming head 12 or a part of the screw housing 11. The propellant charge form 13 is connected via a piston rod 14 to the piston 15 of a pneumatic cylinder 16, which in turn is connected to a compressed air shaft, not shown, via a pressure regulator 17.

Nach Aufgabe der Komponenten in den Kneter 1 wird die Verbindung zur Vakuumpumpe 4 geöffnet. Die Knetschaufeln 7 auf den paarweise angeordneten Wellen 6 sorgen für eine intensive und knetende Durchmischung der Komponenten. Während dieses Vorgangs läuft die Austragschnecke 9 mit umgekehrten Drehsinn um, so daß die Mischung in den Kneter zurückgedrängt wird. Ist eine ausreichender Homogenisierung des Materials erreicht, so wird bei weiterlaufenden Knetschaufeln 7 der Antrieb bei 10 reversiert, so daß die Austragschnecke 9 in umgekehrter Richtung umläuft und die Mischung in das gehäuse 11 und durch das Formstück 12 in die Treibsatzform 13 austrägt. Dieses steht unter Wirkung des gegendrucks des Pneumatikzylinders 16 und verschiebt sich auf dem Gehäuse 11 - in der Zeichnung nach links - nur in dem Maße, wie die Treibsatzform gefüllt wird. Nach einem Arbeitszyklus ist die Treibsatzform soweit zurückgedrängt worden, bis die gewünschte Länge des Treibsatzes in der Treibsatzform erreicht ist und die Form abgenommen werden kann.After the components have been placed in the kneader 1, the connection to the vacuum pump 4 is opened. The kneading blades 7 on the shafts 6 arranged in pairs ensure intensive and kneading mixing of the components. During this process, the discharge screw 9 rotates in the opposite direction, so that the mixture is pushed back into the kneader. If sufficient homogenization of the material is achieved, the drive at 10 is reversed when the kneading blades 7 continue to run, so that the discharge screw 9 rotates in the opposite direction and the mixture is discharged into the housing 11 and through the shaped piece 12 into the propellant mold 13. This is under the effect of the counter pressure of the pneumatic cylinder 16 and moves on the housing 11 - to the left in the drawing - only to the extent that the propellant charge is filled. After a working cycle, the propellant form has been pushed back until the desired length of the propellant in the propellant form is reached and the form can be removed.

Beim gezeigten Ausführungsbeispiel ist die Treibsatzform als einseitig geschlossener Zylinder ausgebildet, an dessen Boden 18 die Kolbenstange 14 mit einem Kopf 19 tose angreift. Die Form kann unmittelbar die Isolationshülle eines fertigen Treibsatzes bilden.In the embodiment shown, the propellant form is designed as a cylinder closed on one side, on the bottom 18 of which the piston rod 14 engages with a head 19 tose. The shape can directly form the insulation shell of a finished propellant charge.

Stattdessen kann die Treibsatzform 13 auch als beidseitig offener Zylinder ausgebildet und an ihrem einen Ende durch einen verschiebbaren Boden geschlossen sein, an dem dann die Kolbenstange angreift. Gegebenenfalls kann auch das Druckstück 19 diesen verschiebbaren Boden bilden.Instead, the propellant charge form 13 can also be designed as a cylinder which is open on both sides and can be closed at one end by a displaceable base on which the piston rod then engages. If necessary, the pressure piece 19 can also form this displaceable base.

Diese Ausbildung gibt insbesondere die Möglichkeit, den Treibsatz mittels des Bodens wieder aus der Form herauszudrücken oder aber den offenen Zylinder durch einen anderen nachträglich zu verschließen.This design gives in particular the possibility of pushing the propellant out of the mold again by means of the base, or to subsequently close the open cylinder by another.

Claims (18)

1. Process for the production of solid propellants, e.g. composite ram jet propellants, comprising at least one pulverulent oxidizer, e.g. ammonium perchlorate, a prepolymer binder as the fuel, optionally further solid fuels and additives, such as plasticizers, stabilizers, burn-off moderators, in which the aforementioned components are mixed and shaped to propelling compositions, accompanied by the addition of a hardener, characterized in that for processing non-pourable mixtures with a viscosity of >, 1000 Pa.s, the components are mixed in kneader in vacuo, the hardener is added to the mixture accompanied by further mixing and the finished mixer is extruded directly from the kneader into a propellant form in opposition to a counterpressure.
2. Process according to claim 1, for producing a composite propellant, characterized in that as oxidizers use is made of ammonium perchlorate or ammonium nitrate and as further energy-rich solids cyclotrimethylene trinitramine (RDX), cyclotetramethylene tetranitramine (HMX), nitroguanidine (NQ) or pentaerythritol tetranitrate (PETN) either alone or in mixed form.
3. Process according to claims 1 or 2, characterized in that as metallic fuels use is made of aluminium, magnesium, boron or zirconium either alone or in mixed form.
4. Process according to one of the claims 1 to 3, charactrized in that as the binder use is made of high viscosity to pasty polybutadiene prepolymers.
5. Process according to claim 4, charactrized in that the binders used are polybutadiene prepolymers with terminal hydroxyl, carboxyl, isocyanate, amino or vinyl groups and are cured by divalent or trivalent hardening agents or initiators to give viscoelastic composite propellants.
6. Process according to claim 4, characterized in that the binders used are polybutadiene-acrylonitrile prepolymers with terminal carboxyl, hydroxyl isocyanate, amino or vinyl groups and are cured by divalent and trivalent hardening agents or by initiators to viscoelastic composite propellants.
7. Process according to claim 4, characterized in that the binders used are polyester, polyether, polytetrahydrofuran or polycaprolactone prepolymers with terminal hydroxyl groups.
8. Process according to claim 1 for producing solid ram jet propellants, charactrized in that the oxidizer used is ammonium perchlorate and as a further energy-rich solid cyclotrimethylene trinitramine (RDX) or cyclotetramethylene tetranitramine (HMX) is used either alone or in mixed form in proportions of < 35%.
9. Process according to claim 8, characterized in that the metallic fuels used are boron, aluminium, magnesium or zirconium either alone or mixed in proportions of 30 to 70%.
10. Process according to claim 8, characterized in that the binder used is high viscosity to pasty polybutadiene prepolymers.
11. Process according to claim 10, characterized in that polybutadiene prepolymers with terminal hydroxyl, carboxyl, isocyanate, amino or vinyl groups are used and cured by divalent and trivalent hardening agents or by initiators to viscoelastic ram jet propellants.
12. Process according to claim 10, characterized in that polybutadieneacrylonitrile prepolymers with terminal carboxyl, hydroxyl, isocyanate, amino or vinyl groups are used and cured by divalent or trivalent hardening agents, or by initiators to viscoelastic ram jet propellants.
13. Apparatus for performing the process according to one of the claims 1 to 12, characterized by a horizontal kneader (1), which is provided with a kneading chamber (2) connectable to a vacuum and horizontally arranged, intermeshing kneading blades (7), a discharge screw (9) arranged on the bottom of the kneading chamber and a propellant composition form (13) connected to its outlet, whose form volume is approximately zero in the starting position and under the action of the feed pressure of the discharge screw and whilst maintaining a counterpressure can be enlarged to the desired form volume.
14. Apparatus according to claim 13, characterized in that the kneading blades (7) are oppositely directed and are driven at different speeds.
15. Apparatus according to claims 12 or 14, characterized in that during the filling of the kneader (1) and during the kneading process, the discharge screw (9) rotates in the opposite rotation direction to the discharge movement.
16. Apparatus according to one of the claims 13 to 15, characterized in that the propellant composition form (13) is constructed as a propellant composition combustion chamber.
17. Apparatus according to one of the claims 13 to 16, characterized in that the propellant composition form (13) is cup-shaped, the casing (11) of the discharge screw (9) is checked from the discharge end, is guided on the casing and supported on a pressure cylinder (15, 16) producing the counterpressure.
18. Apparatus according to one of the claims 13 to 16, characterized in that the propellant composition form (13) is cup-shaped with a piston-like displaceable base and is connected to the casing (11) of the discharge screw (9) and the base of the propellant composition form is connected to a pressure cylinder producing the counterpressure.
EP19860108926 1985-07-04 1986-07-01 Process and apparatus for the production of solid propellants Expired EP0208983B1 (en)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
DE3523953 1985-07-04
DE19853523953 DE3523953A1 (en) 1985-07-04 1985-07-04 METHOD AND DEVICE FOR PRODUCING SOLID FUELS

Publications (2)

Publication Number Publication Date
EP0208983A1 EP0208983A1 (en) 1987-01-21
EP0208983B1 true EP0208983B1 (en) 1989-10-18

Family

ID=6274968

Family Applications (1)

Application Number Title Priority Date Filing Date
EP19860108926 Expired EP0208983B1 (en) 1985-07-04 1986-07-01 Process and apparatus for the production of solid propellants

Country Status (2)

Country Link
EP (1) EP0208983B1 (en)
DE (1) DE3523953A1 (en)

Families Citing this family (10)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE3830902C1 (en) * 1988-09-10 1992-04-09 Diehl Gmbh & Co, 8500 Nuernberg, De
US5348596A (en) * 1989-08-25 1994-09-20 Hercules Incorporated Solid propellant with non-crystalline polyether/inert plasticizer binder
DE4026468C2 (en) * 1990-08-22 1998-10-08 Hercules Inc Solid fuels with a binder of non-crystalline polyether / high-energy plasticizer
DE4435523C1 (en) * 1994-10-05 1996-06-05 Fraunhofer Ges Forschung Solid fuel based on phase-stabilized ammonium nitrate
DE4435524C2 (en) * 1994-10-05 1996-08-22 Fraunhofer Ges Forschung Solid fuel based on pure or phase-stabilized ammonium nitrate
DE19516528C1 (en) * 1995-05-05 1996-12-12 Fraunhofer Ges Forschung Solid composite fuel and process for its manufacture
DE19605613A1 (en) * 1996-02-15 1997-08-21 Dynamit Nobel Ag Missile-powered ranged weapon
FR2774684B1 (en) * 1998-02-10 2000-03-03 Poudres & Explosifs Ste Nale NEW NON-DETONATED PYROTECHNIC MATERIALS FOR MICROSYSTEMS
US6835255B2 (en) * 1998-06-01 2004-12-28 Alliant Techsystems Inc. Reduced energy binder for energetic compositions
CN103073369B (en) * 2013-01-30 2015-04-01 中国工程物理研究院化工材料研究所 Casting-curing insensitive high-explosion-heat explosive and preparation method thereof

Family Cites Families (8)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE299029C (en) *
US2939176A (en) * 1954-12-30 1960-06-07 Phillips Petroleum Co Molding of propellants
US3269880A (en) * 1965-01-13 1966-08-30 Visnov Martin Heat resistant butadiene-acrylonitrile propellants
US3948698A (en) * 1967-09-06 1976-04-06 Hercules Incorporated Solid propellant compositions having epoxy cured, carboxy-terminated rubber binder
US4120709A (en) * 1973-04-25 1978-10-17 Thiokol Corporation Technique for improving processibility of certain composite propellants by calcining the iron oxide burning rate catalyst
US3924405A (en) * 1973-06-07 1975-12-09 Aerojet General Co Solid propellants with stability enhanced additives of particulate refractory carbides or oxides
CA1062847A (en) * 1975-08-11 1979-09-18 Gonzague Duchesne Solid propellants containing polyether or polyester binders
DE2825349C2 (en) * 1978-06-09 1982-04-08 C.& W. Berges, Maschinenfabrik, 5277 Marienheide Screw press for preplasticizing thermoset press masses (thermosets)

Also Published As

Publication number Publication date
EP0208983A1 (en) 1987-01-21
DE3523953C2 (en) 1987-07-23
DE3523953A1 (en) 1987-01-15

Similar Documents

Publication Publication Date Title
US5487851A (en) Composite gun propellant processing technique
DE60312399T2 (en) Apparatus and method for stirring mixing
EP0208983B1 (en) Process and apparatus for the production of solid propellants
DE2117854C3 (en) Composite explosives and their manufacture
EP0046230A2 (en) Pyrotechnic fog or smoke producing charge having a casing, its composition and method for its manufacture
DE2232436A1 (en) MIXING DEVICE
DE1508672B1 (en) MIXER FOR THE PRODUCTION OF SELF-HARDING MOLDING SAND
DE2461646A1 (en) PROCESS FOR MANUFACTURING DRIVING CHARGE POWDERS, IN PARTICULAR NITROGUANIDINE POWDERS
DE4315707A1 (en) High-energy binder with improved mechanical properties
DE3319541C1 (en) Plastic fuel compositions and process for their preparation
EP0157911B1 (en) Process for producing resin-bonded propellants and explosives
CH615143A5 (en)
EP0203260B1 (en) Kneading machine
EP1089955B1 (en) Method for producing pyrotechnic primer charges
DE1646283B2 (en) PROCESS FOR THE PRODUCTION OF EXPLOSIVES HIGH STRENGTH WITH SELECTABLE DEFINED DETONATION SPEED
DE2457078C3 (en) Device for dosing powder additives for extruders or similar plastic mass processing machines
DE1816209A1 (en) Polymeric compositions and processes for their production
DE10027413B4 (en) A method of making a blowing agent composition using a dry blending method
AT214329B (en) Device for the continuous production of guns and propellants
DE2417116C2 (en) Mixing extruder
DE2448615C3 (en) Solid propellants and their uses
DE2124466A1 (en) Scroll extruder - with radially displacing rams of adjustable stroke and speed in the scroll housing
EP0051881B1 (en) Process for the continuous production of a monobasic powder
DE3448139C2 (en) Device for producing plastics-bound propellant powders and explosives
DE2230023A1 (en) Centrifugal compressor

Legal Events

Date Code Title Description
PUAI Public reference made under article 153(3) epc to a published international application that has entered the european phase

Free format text: ORIGINAL CODE: 0009012

AK Designated contracting states

Kind code of ref document: A1

Designated state(s): BE CH DE FR GB IT LI SE

17P Request for examination filed

Effective date: 19870404

17Q First examination report despatched

Effective date: 19880506

RBV Designated contracting states (corrected)

Designated state(s): BE CH FR GB IT LI SE

GRAA (expected) grant

Free format text: ORIGINAL CODE: 0009210

REG Reference to a national code

Ref country code: DE

Ref legal event code: 8566

AK Designated contracting states

Kind code of ref document: B1

Designated state(s): BE CH FR GB IT LI SE

ET Fr: translation filed
ITF It: translation for a ep patent filed

Owner name: DR. ING. A. RACHELI & C.

GBT Gb: translation of ep patent filed (gb section 77(6)(a)/1977)
PLBE No opposition filed within time limit

Free format text: ORIGINAL CODE: 0009261

STAA Information on the status of an ep patent application or granted ep patent

Free format text: STATUS: NO OPPOSITION FILED WITHIN TIME LIMIT

26N No opposition filed
ITTA It: last paid annual fee
PGFP Annual fee paid to national office [announced via postgrant information from national office to epo]

Ref country code: BE

Payment date: 19940713

Year of fee payment: 9

PGFP Annual fee paid to national office [announced via postgrant information from national office to epo]

Ref country code: FR

Payment date: 19940729

Year of fee payment: 9

PGFP Annual fee paid to national office [announced via postgrant information from national office to epo]

Ref country code: SE

Payment date: 19940731

Year of fee payment: 9

PGFP Annual fee paid to national office [announced via postgrant information from national office to epo]

Ref country code: CH

Payment date: 19940930

Year of fee payment: 9

EAL Se: european patent in force in sweden

Ref document number: 86108926.6

PGFP Annual fee paid to national office [announced via postgrant information from national office to epo]

Ref country code: GB

Payment date: 19950608

Year of fee payment: 10

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: SE

Effective date: 19950702

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: LI

Effective date: 19950731

Ref country code: CH

Effective date: 19950731

Ref country code: BE

Effective date: 19950731

BERE Be: lapsed

Owner name: FRAUNHOFER-G.- ZUR FORDERUNG DER ANGEWANDTEN FORS

Effective date: 19950731

REG Reference to a national code

Ref country code: CH

Ref legal event code: PL

EUG Se: european patent has lapsed

Ref document number: 86108926.6

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: FR

Effective date: 19960430

REG Reference to a national code

Ref country code: FR

Ref legal event code: ST

REG Reference to a national code

Ref country code: FR

Ref legal event code: ST

REG Reference to a national code

Ref country code: FR

Ref legal event code: ST

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: GB

Effective date: 19960701

GBPC Gb: european patent ceased through non-payment of renewal fee

Effective date: 19960701

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: IT

Free format text: LAPSE BECAUSE OF NON-PAYMENT OF DUE FEES;WARNING: LAPSES OF ITALIAN PATENTS WITH EFFECTIVE DATE BEFORE 2007 MAY HAVE OCCURRED AT ANY TIME BEFORE 2007. THE CORRECT EFFECTIVE DATE MAY BE DIFFERENT FROM THE ONE RECORDED.

Effective date: 20050701