EP0451048B1 - Process and apparatus for drying and degassing powders - Google Patents

Process and apparatus for drying and degassing powders Download PDF

Info

Publication number
EP0451048B1
EP0451048B1 EP91400894A EP91400894A EP0451048B1 EP 0451048 B1 EP0451048 B1 EP 0451048B1 EP 91400894 A EP91400894 A EP 91400894A EP 91400894 A EP91400894 A EP 91400894A EP 0451048 B1 EP0451048 B1 EP 0451048B1
Authority
EP
European Patent Office
Prior art keywords
riffler
powder
compartment
hourglass
vessel
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 - Lifetime
Application number
EP91400894A
Other languages
German (de)
French (fr)
Other versions
EP0451048A1 (en
Inventor
Jean-Claude Baudin
Dominique Le Potier
Jean-Claude Couterne
Philippe Jacquin
Jean-Paul Levaillant
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.)
Commissariat a lEnergie Atomique et aux Energies Alternatives CEA
Original Assignee
Commissariat a lEnergie Atomique CEA
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 Commissariat a lEnergie Atomique CEA filed Critical Commissariat a lEnergie Atomique CEA
Publication of EP0451048A1 publication Critical patent/EP0451048A1/en
Application granted granted Critical
Publication of EP0451048B1 publication Critical patent/EP0451048B1/en
Anticipated expiration legal-status Critical
Expired - Lifetime legal-status Critical Current

Links

Images

Classifications

    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F26—DRYING
    • F26B—DRYING SOLID MATERIALS OR OBJECTS BY REMOVING LIQUID THEREFROM
    • F26B11/00—Machines or apparatus for drying solid materials or objects with movement which is non-progressive
    • F26B11/02—Machines or apparatus for drying solid materials or objects with movement which is non-progressive in moving drums or other mainly-closed receptacles
    • F26B11/04—Machines or apparatus for drying solid materials or objects with movement which is non-progressive in moving drums or other mainly-closed receptacles rotating about a horizontal or slightly-inclined axis
    • F26B11/049—Machines or apparatus for drying solid materials or objects with movement which is non-progressive in moving drums or other mainly-closed receptacles rotating about a horizontal or slightly-inclined axis with provisions for working under increased or reduced pressure, with or without heating
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01F—MIXING, e.g. DISSOLVING, EMULSIFYING OR DISPERSING
    • B01F29/00—Mixers with rotating receptacles
    • B01F29/40—Parts or components, e.g. receptacles, feeding or discharging means
    • B01F29/401—Receptacles, e.g. provided with liners
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01F—MIXING, e.g. DISSOLVING, EMULSIFYING OR DISPERSING
    • B01F29/00—Mixers with rotating receptacles
    • B01F29/40—Parts or components, e.g. receptacles, feeding or discharging means
    • B01F29/401—Receptacles, e.g. provided with liners
    • B01F29/402—Receptacles, e.g. provided with liners characterised by the relative disposition or configuration of the interior of the receptacles
    • B01F29/4021—Multi-compartment receptacles
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01F—MIXING, e.g. DISSOLVING, EMULSIFYING OR DISPERSING
    • B01F29/00—Mixers with rotating receptacles
    • B01F29/40—Parts or components, e.g. receptacles, feeding or discharging means
    • B01F29/401—Receptacles, e.g. provided with liners
    • B01F29/402—Receptacles, e.g. provided with liners characterised by the relative disposition or configuration of the interior of the receptacles
    • B01F29/4022—Configuration of the interior
    • B01F29/40222—Configuration of the interior provided with guide tubes on the wall or the bottom
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F26—DRYING
    • F26B—DRYING SOLID MATERIALS OR OBJECTS BY REMOVING LIQUID THEREFROM
    • F26B11/00—Machines or apparatus for drying solid materials or objects with movement which is non-progressive
    • F26B11/02—Machines or apparatus for drying solid materials or objects with movement which is non-progressive in moving drums or other mainly-closed receptacles
    • F26B11/026—Arrangements for charging or discharging the materials to be dried, e.g. discharging by reversing drum rotation, using spiral-type inserts

Definitions

  • the field of the invention is that of drying and degassing of ceramic or metallic powders. These operations are implemented as part of the production of massive parts produced by hot isostatic pressing.
  • the consolidation of powders must use a material free of moisture and residual gases.
  • the latter can either react with the product to be compacted (reaction with H2O for example), or cause gaseous inclusions disturbing the properties of the solid obtained (density, weldability, ductility).
  • a first existing solution consists in degassing the powder statically.
  • the mass of powder is in this case subjected to vacuum and temperature in its sheath. With this process there is great difficulty in obtaining and guaranteeing a sufficient level of vacuum within the mass of powder.
  • Another drawback lies in the fact that the gaseous products extracted from the lower layers are redeposited on the upper layers, which have become more reactive. Finally, there is a risk of triggering natural sintering phenomena.
  • a second solution consists in mechanically brewing the powders (see, for example, document US-A-3,599,709). This mixing causes on the one hand pollution problems due to abrasion and on the other hand a technological limitation concerning the maximum temperature and the level of vacuum used.
  • the object of the invention is to remedy the drawbacks of the above methods and to propose both a method and an installation for drying and degassing powders.
  • the mixing of the powder is carried out by a slow inversion of the hourglass in a first direction, to gradually pass the powder from one compartment to another, then by slowly turning the hourglass in a second direction opposite to the first direction to return the powder to the first compartment.
  • This phase makes it possible to separate the grains of powder from each other during the passage through the baffle.
  • the mixing and the passage of the powder from one compartment to the other can be improved by means of at least one series of oscillations around its horizontal axis during the turning cycle.
  • the heating means are heating plates placed outside the compartments and the baffle.
  • the means for rotating the hourglass consist of a geared motor communicating a slow rotation movement to a first sleeve of a movable coupling with radial freedom, a second sleeve being integral with a rotation drive shaft hourglass.
  • the hourglass is mounted to rotate freely on a mobile carriage by means of rollers on which it is placed by means of treads.
  • rollers are mounted on articulated boogies arranged two by two.
  • the enclosure comprises inclined supports on which come to rest, during the horizontal translation of the mobile assembly, second rollers mounted free in rotation on a base plate placed below the hourglass so that the hourglass is supported on the enclosure, when it is inside of it.
  • the main concept of the process according to the invention consists in putting the powder under vacuum, in brewing it slowly while raising its temperature (for example up to 600 ° C., maximum value on the operational installation).
  • a drying and degassing device is used, marked 10 in all the figures and more commonly called an hourglass. It consists of a wall 19 of very special shape terminated at its ends by a flange.
  • the hourglass 10 is placed in an enclosure inside which a vacuum is produced up to 10 ⁇ 6T (1.333.10 ⁇ 4 Pa).
  • the hourglass is raised to a temperature that can exceed 700 ° C. Brewing takes place under these temperature and pressure conditions.
  • the powder temperature is followed by immersion thermocouples in compartments 4 and 8.
  • FIG 1A shows in section the hourglass in its powder loading position.
  • the latter is not identified by a numerical reference in the figures, but is shown diagrammatically by one or more spots of small dots.
  • the hourglass entrance, formed by the first end of a loading and unloading duct 2 is located, in this position, above the body of the hourglass 10, that is to say in the highest position that it can take, during a complete rotation of the hourglass 10.
  • This position is used to channel the powder, intended to be treated, inside the hourglass 10.
  • the powder falls by gravity along the loading and unloading pipe 2 to arrive in a first compartment 4 which communicates with the loading and unloading pipe 2 through its second end.
  • the hourglass 10 has a second compartment 8 connected to the first compartment 4 via a baffle 6.
  • the relative positions of the two compartments 4 and 8 and their communication with the baffle 6 must be such that, in the loading position shown in FIG. 1A, the powder remains on an internal wall 16 of the first compartment 4 without being able to progress towards the second compartment 8.
  • the outer walls of the two compartments 4 and 8 and of the baffle 6 are partially covered by heating means 12, which are preferably hot plates.
  • heating means 12 which are preferably hot plates.
  • the hourglass 10 is rotated in a first direction, symbolized by the arrow in FIG. 1B.
  • this rotation is of the order of a quarter turn.
  • the first compartment 4 is located above the second compartment 8 and the powder falls naturally by gravity into the baffle 6 and into the second compartment 8.
  • a deflector 14 is located at the entrance to the baffle 6. Its function is to prevent the powder from returning directly to the conduit of loading and unloading 2, when it is desired to drop it into the second compartment 8. In these figures, this deflector 14 constitutes the extension of one of the two walls of the loading and unloading duct 2.
  • the baffle 6 mainly consists of two segments of straight tubes communicating with one another at an acute angle.
  • the baffle 6 communicates with the two compartments 4 and 8, being oriented so as to form, with the internal walls 16 and 18 constituting the respective bottoms of the two compartments 4 and 8, an acute angle.
  • the powder in the first compartment 4 must pass three abrupt changes of direction before falling into the bottom of the second compartment 8.
  • This embodiment is only an example, any other form of baffle can be used from the instant that the desired mixing is obtained.
  • the hourglass 10 is driven by several slow successive and reverse rotations. As a result, the hourglass is slowly shaken and the powder gradually descends to the bottom of the second compartment 8 where it is stirred.
  • the cycle continues with an inverted reversal of the hourglass 10.
  • the arrow in this figure 1C indicates a direction reversed with respect to the direction symbolized by the arrow in FIG. 1B.
  • the cycle preferably comprises a phase of agitation similar to that taking place when the second compartment 8 is at the bottom. This agitation with the first compartment 4 placed at the bottom is however generally of greater amplitude. It is indeed necessary to ensure the complete descent of all the powder located in the baffle 6 and in the second compartment 8.
  • the number of transfers between cavities 4 and 8, as well as the oscillation cycles are a function of certain parameters.
  • FIG. 2 shows in longitudinal section, the assembly of a drying and degassing installation according to the invention.
  • the latter mainly comprises the assembly consisting of the oven itself, that is to say the vacuum chamber 20 and the hourglass 10, equipped with its means of rotation which are located to its right.
  • This assembly is mounted integrally on a carriage 16 movable in horizontal translation relative to the ground 18.
  • the translation system by mother screw is not shown here.
  • the installation further comprises an enclosure 20 fixed relative to the ground 18 and inside which the hourglass 10 is housed so that the drying and degassing operations are carried out there.
  • This enclosure 20 is completed with a removable door 30, fitted with a seal 31, mounted on the assembly of the hourglass 10 and of the movable support 16.
  • the enclosure 20 is also completed with a first depression orifice preferably in the form of a plug 44 attached to the walls of the enclosure 20, and of an outlet receptacle 52 for the powder, placed in the lower part of the enclosure 20 and opening into a vacuum valve 54.
  • the hourglass 10 is loaded with powder when it is placed outside the enclosure. Once this loading has been carried out, the hourglass is introduced inside the enclosure 20 which is hermetically closed using the watertight door 30. The latter is mounted fixed relative to the mobile support 16. The vacuum is then done inside the enclosure using at least one vacuum circuit symbolized by the plug 44 placed in the upper part of the enclosure 20. In fact, it is preferable to use a first primary circuit to start slowly creating a vacuum in the enclosure without sucking the powder placed in the hourglass 10. A second secondary circuit is then used to obtain the desired vacuum more quickly.
  • the hourglass 10 and its rotational drive means are mounted movable in translation on the carriage 16 to allow the maintenance of the hourglass 10 without mounting or dismounting thereof, and the loading of the powder therein.
  • the drying and degassing method according to the invention can be implemented with an installation in which a loading hole would be provided in the top of the enclosure and in which the hourglass would remain inside the enclosure .
  • Such an installation would make it possible to eliminate the mobile carriage 16, the door 30 and its sealing system and the system for positioning the hourglass inside the enclosure.
  • such an installation would therefore require an additional loading opening provided in the upper part of the enclosure and to review the operations necessary for maintenance.
  • the means for driving the hourglass 10 in rotation consist of a geared motor 22 fixed on the movable carriage 16. It drives a drive shaft 26 of the hourglass 10, by means of a transmission assembly symbolized in broken lines by a belt 24.
  • the latter drives in rotation the transmission shaft 26 by means of a movable coupling with radial freedom 25 which is preferably an OLDHAM seal.
  • a movable coupling with radial freedom 25 which is preferably an OLDHAM seal.
  • the belt 24 drives a first sleeve of this OLDHAM joint, the second sleeve of this joint being integral with the drive shaft 26.
  • the drive shaft 26 is preferably hollow. This allows the passage of the feed connection of the heating plates 12 of the hourglass 10 and of possible control thermocouples also located on the hourglass 10. This drive shaft 26 passes through the door 30. The sealing is then ensured by a passage tight turn 27 placed around the drive shaft 26.
  • FIG. 2 the mobile assembly of the hourglass 10 and the mobile carriage 16 is shown in the intermediate position, that is to say that the hourglass 10 is half out of the enclosure 20. In the loading position of the powder, this assembly is completely removed from the enclosure 20.
  • the hourglass 10 is then mounted in cantilever on the mobile carriage 16. Specifically, it is suspended by means of a journal 34 placed in at least one notch 36 secured to door 30. This pin 34 is integral with the hourglass 10 and is placed at the height of the upper wall of the apron 10, next to the right flange 46 of the hourglass 10.
  • the whole hourglass 10 also rests on the door 30 by lower supports 38.
  • the movable assembly is then translated to the left of the figure, until the hourglass 10 takes the position sketched in dashed lines, the door 30 being applied against the right end of the tank 20.
  • the latter is therefore closed hermetically thanks to the seal 31 placed on the door 30 and bearing on the face of the tank 20.
  • the hourglass 10 resting in the tank 20 includes inclined supports 48 fixed on its bottom and positioned in correspondence with positioning rollers 50 fixed below the hourglass 10, on a base plate 60, but free to rotate around horizontal axes and thus acting as rollers.
  • each positioning roller 50 comes to tangent and roll on an inclined support 48.
  • the hourglass 10 is then slightly raised.
  • the translation of the mobile assembly ends with the arrival of the positioning rollers 50 on a horizontal portion of the inclined supports 48 corresponding to the working position of the hourglass 10. The latter is then unhooked from the fixing hook 36 and n ' is no longer supported by door 30.
  • the degree of freedom in horizontal rotation of the hourglass 10 is ensured by the fact that the latter is placed on rollers 40 placed outside the flanges 46 of the hourglass 10.
  • the left half of Figure 3 is a vertical section of Figure 2 at the line AA.
  • the rollers 40 are grouped two by two by means of articulated arms 56 thus forming boogies.
  • Each boogie is articulated around a horizontal axis of articulation 58 secured to the base plate 60 of the hourglass 10.
  • the hourglass 10 On the outside of each of the flanges 46 (FIG. 2), the hourglass 10 has a tread 42. Each of them is placed on at least two boogies of rolling rollers 40 placed in correspondence below them, so that the hourglass 10 can rotate freely around its horizontal axis because it rests only on rollers 40.
  • FIG. 3 In Figure 3 is shown the cap 44 symbolizing the means of depression of the enclosure 20.
  • a water inlet 62 is also shown on the top of the enclosure 20. It is intended for the circulation of water between the two walls of the enclosure 20. The presence of the double wall of the enclosure 20 allows permanent circulation of water around the hourglass 10 to maintain a safety temperature on the exterior surface of the enclosure 20.
  • This type of mounting of the hourglass 10 on rolling rollers 54 makes it possible to limit the contact pressures and to allow a slight vertical elevation of the axis of the hourglass 10 without inducing constraints.
  • the elevation is due to a variation in bearing diameter on the rollers 40 caused by thermal expansion.
  • the axes and the rollers 40 are preferably made of refractory metals and ceramics to ensure operation in an environment which does not allow lubrication of the contacts.
  • the first operation consists in placing the powder in the hourglass 10, then in introducing the hourglass into the enclosure 20. This operation is followed by the evacuation of the interior of the enclosure 20. The powder is then stirred slowly at the interior of the hourglass 10 according to a determined cycle of turning the hourglass, an example of which is given below.
  • This brewing cycle varies in very large proportions. The heating of the powder can be incremented in stages or carried out by a continuous rise in temperature. After the brewing cycle, the powder is cooled naturally. Finally, it is evacuated from the hourglass while being kept under vacuum for storage in a hopper.
  • the volume of powder used is preferably of the order of six liters.
  • FIG. 4 An example of the powder brewing cycle is shown diagrammatically in FIG. 4.
  • the 0 ° mark corresponds to the loading position of the hourglass.
  • the first clockwise rotation of the hourglass exceeds 110 °.
  • the hourglass 10 then undergoes a determined number of slow oscillations of increasing amplitude, in some cases reaching 90 °.
  • the hourglass 10 is then turned 180 ° and is again subjected to oscillations of greater amplitudes which can exceed 90 ° and during which the powder is transferred from the cavities 4 to 8 and vice versa.
  • the different rotations of the hourglass are symbolized by arrows in the shape of an arc of a circle.
  • the circled numbers assigned to these arrows are representative of the chronology of these rotations.
  • FIG. 5 the installation is used in a degassing and envelope filling assembly for hot isostatic compaction.
  • two installations have been shown schematically.
  • the one on the right shows a first hourglass 10 enclosed in an enclosure 20.
  • This first installation diagrams a degassing operation.
  • the installation on the left shows a second hourglass 10 in a loading position.
  • This second hourglass 10 is taken out of the enclosure 20.
  • the assembly is placed in a confinement enclosure 70 to allow the various operations to be carried out under a special atmosphere, or to avoid contamination problems.
  • each enclosure 20 Below each enclosure 20, an outlet receptacle 52 is placed to collect the treated powder. This receptacle 52 results in a vacuum valve 54. The latter is suitable for transferring the powder. Downstream of each vacuum valve 54 is a hopper 56, the capacity of which corresponds to that of the hourglasses 10. Each hopper 56 is followed by a conveying device allowing the powder to be transferred to a zone of use. Thanks to the vacuum valve 54, the downstream assembly is maintained in a controlled atmosphere, and more specifically under vacuum, while the enclosure 20 must be open and the hourglass 10 recharged. At the bottom of each hopper 56 is a calibrated and removable nozzle. It provides closure by accumulation at the outlet on the upper face of a vibrating passage 58.
  • a trident device 62 comprises at least two branches which can be isolated from the rest of the equipment by vacuum valves 54A, 54B. In the center of the trident is a control device 64 making it possible to check the filling level of the sheath 67.
  • valves 54, 54A and 54B The part between the valves 54, 54A and 54B is permanently vacuum.
  • the sheath 67 is then closed by a crimping and welding device not shown here.
  • the entire installation can be controlled by a programmable controller which manages the powder treatment cycle.
  • the latter includes a slow primary emptying, then the ease of secondary vacuum, heating and the hourglass rotations.
  • This programmable controller can also manage the safety associated with the vacuum, temperature and valve opening functions.
  • FIG. 5 The assembly described in FIG. 5 is only an example of use of the installation according to the invention. We can indeed consider other possible assemblies using multiple channels arranged for example in a carousel.
  • the treatment of the powder can also be carried out under a controlled atmosphere or in a reactive atmosphere. Glove box mounting can even be considered for the treatment of toxic products.
  • the assembly described in FIG. 5 is particularly intended for vacuum encapsulation of powder intended for densification by hot isostatic pressing.

Abstract

The process and apparatus according to the invention dry and degas powders by using a dynamic process under vacuum and at a high temperature in a special device called a "sand box" (10). This sand box (10) is subjected to slow alternating rotatory movements so as to cause the powder being treated to pass progressively from one compartment to another, both compartments being inside the sand box (10). The rotations thus enable the powder to be agitated for a variable but predetermined time. The sand box (10) is introduced into a leakproof vessel (20) situated upstream of a possible valve that might enable the treated powder to be routed towards a storage compartment, or to be sent for immediate use, without releasing the vacuum. The degassing operation is carried out under vacuum and at a high temperature. Application to the manufacture of components sintered by hot isostatic pressing. <IMAGE>

Description

Le domaine de l'invention est celui du séchage et du dégazage des poudres céramiques ou métalliques. Ces opérations sont mises en oeuvre dans le cadre de la réalisation de pièces massives élaborées par pressage isostatique à chaud.The field of the invention is that of drying and degassing of ceramic or metallic powders. These operations are implemented as part of the production of massive parts produced by hot isostatic pressing.

En effet, la consolidation de poudres doit mettre en oeuvre un matériau exempt d'humidité et de gaz résiduels. Ces derniers peuvent soit réagir avec le produit à compacter (réaction avec H₂O par exemple), soit provoquer des inclusions gazeuses perturbant les propriétés du massif obtenu (densité, soudabilité, ductilité).Indeed, the consolidation of powders must use a material free of moisture and residual gases. The latter can either react with the product to be compacted (reaction with H₂O for example), or cause gaseous inclusions disturbing the properties of the solid obtained (density, weldability, ductility).

Une première solution existante consiste à dégazer la poudre de manière statique. La masse de poudre est dans ce cas soumise au vide et à la température dans sa gaine. On éprouve avec ce procédé une grande difficulté pour obtenir et garantir un niveau suffisant de vide au sein de la masse de poudre. Un autre inconvénient réside dans le fait que les produits gazeux extraits des couches inférieures viennent se redéposer sur les couches supérieures, devenues plus réactives. Enfin, il persiste un risque de déclencher les phénomènes de frittage naturels.A first existing solution consists in degassing the powder statically. The mass of powder is in this case subjected to vacuum and temperature in its sheath. With this process there is great difficulty in obtaining and guaranteeing a sufficient level of vacuum within the mass of powder. Another drawback lies in the fact that the gaseous products extracted from the lower layers are redeposited on the upper layers, which have become more reactive. Finally, there is a risk of triggering natural sintering phenomena.

Une deuxième solution consiste à brasser mécaniquement les poudres (voir, par exemple, le document US-A-3 599 709). Ce brassage entraîne d'une part des problèmes de pollution dus à l'abrasion et d'autre part une limitation technologique concernant la température maximale et le niveau de vide mis en oeuvre.A second solution consists in mechanically brewing the powders (see, for example, document US-A-3,599,709). This mixing causes on the one hand pollution problems due to abrasion and on the other hand a technological limitation concerning the maximum temperature and the level of vacuum used.

Le but de l'invention est de remédier aux inconvénients des méthodes précitées et de proposer à la fois un procédé et une installation de séchage et de dégazage de poudres.The object of the invention is to remedy the drawbacks of the above methods and to propose both a method and an installation for drying and degassing powders.

A cet effet, un premier objet de l'invention est un procédé de séchage et de dégazage des poudres, comprenant les étapes suivantes :

  • chargement de la poudre dans un dispositif de séchage et de dégazage, appelé "sablier" ;
  • faire le vide relatif dans ledit sablier ;
  • chauffer l'intérieur du sablier à une température permettant à la poudre d'atteindre une température égale à 600°C et, simultanément, brasser très lentement la poudre selon un cycle déterminé de retournements du sablier ;
  • refroidir l'intérieur du sablier ;
  • vider le sablier de la poudre traitée en maintenant cette poudre stockée sous vide.
To this end, a first object of the invention is a method for drying and degassing powders, comprising the following steps:
  • loading the powder into a drying and degassing device, called an "hourglass";
  • make the relative vacuum in said hourglass;
  • heating the interior of the hourglass to a temperature allowing the powder to reach a temperature equal to 600 ° C. and, simultaneously, very slowly brewing the powder according to a determined cycle of turning the hourglass;
  • cool the interior of the hourglass;
  • empty the hourglass of the treated powder while keeping this powder stored under vacuum.

Le retournement lent du sablier permet d'éviter les problèmes engendrés par l'abrasion, le parcours effectué par la poudre garantit un dégazage optimal.The slow turning of the hourglass avoids the problems caused by abrasion, the course taken by the powder guarantees optimal degassing.

Dans le cas où le sablier comporte au moins deux compartiments communiquant l'un avec l'autre au moyen d'une chicane, le brassage de la poudre s'effectue par un lent retournement du sablier dans un premier sens, pour faire passer progressivement la poudre d'un compartiment à l'autre, puis par un lent retournement du sablier dans un deuxième sens opposé au premier sens pour faire revenir la poudre dans le premier compartiment. Cette phase permet de désolidariser les grains de poudre les uns des autres lors du passage dans la chicane.In the case where the hourglass has at least two compartments communicating with each other by means of a baffle, the mixing of the powder is carried out by a slow inversion of the hourglass in a first direction, to gradually pass the powder from one compartment to another, then by slowly turning the hourglass in a second direction opposite to the first direction to return the powder to the first compartment. This phase makes it possible to separate the grains of powder from each other during the passage through the baffle.

Le brassage et le passage de la poudre d'un compartiment à l'autre peuvent être améliorés grâce à au moins une série d'oscillations autour de son axe horizontal au cours du cycle de retournement.The mixing and the passage of the powder from one compartment to the other can be improved by means of at least one series of oscillations around its horizontal axis during the turning cycle.

Un deuxième objet de l'invention est une installation pour la mise en oeuvre du procédé qui vient d'être décrit. Celle-ci comprend :

  • un dispositif de séchage et de dégazage, appelé "sablier", monté tournant autour d'un axe horizontal, comportant :
    • * un conduit de chargement et de déchargement de la poudre communiquant avec :
    • * un premier compartiment communiquant d'autre part avec :
    • * une chicane communiquant elle-même avec :
    • * un deuxième compartiment,
    le conduit de chargement et de déchargement et la chicane débouchant dans le premier compartiment de manière à ce que, pour une première série de positions angulaires du sablier, la poudre introduite dans le conduit de chargement et de déchargement, ou venant du deuxième compartiment, tombe et reste par gravité dans le premier compartiment, la chicane débouchant dans le deuxième compartiment de manière à ce que, pour une deuxième série de positions angulaires du sablier différentes des positions angulaires de la première série, la poudre venant du premier compartiment tombe progressivement et reste dans le second compartiment, la différence angulaire des deux séries de positions angulaires correspondant avec les retournements du sablier,
  • des moyens de chauffage du sablier ;
  • des moyens de mise en rotation du sablier; et
  • des moyens de mise sous vide du sablier et de maintien sous vide de la poudre stockée.
A second object of the invention is an installation for implementing the method which has just been described. This includes:
  • a drying and degassing device, called an "hourglass", mounted rotating around a horizontal axis, comprising:
    • * a powder loading and unloading conduit communicating with:
    • * a first compartment communicating on the other hand with:
    • * a chicane communicating itself with:
    • * a second compartment,
    the loading and unloading duct and the baffle opening into the first compartment so that, for a first series of angular positions of the hourglass, the powder introduced into the loading and unloading duct, or coming from the second compartment, falls and remains by gravity in the first compartment, the baffle opening into the second compartment so that, for a second series of angular positions of the hourglass different from the angular positions of the first series, the powder coming from the first compartment falls gradually and remains in the second compartment, the angular difference of the two series of angular positions corresponding to the hourglass reversals,
  • means for heating the hourglass;
  • means for rotating the hourglass; and
  • means for evacuating the hourglass and maintaining the stored powder under vacuum.

Dans la réalisation préférentielle de cette installation, les moyens de chauffage sont des plaques chauffantes placées à l'extérieur des compartiments et de la chicane.In the preferred embodiment of this installation, the heating means are heating plates placed outside the compartments and the baffle.

De préférence, les moyens de mise en rotation du sablier sont constitués d'un motoréducteur communiquant un mouvement de lente rotation à un premier manchon d'un accouplement mobile à liberté radiale, un deuxième manchon étant solidaire d'un arbre d'entraînement en rotation du sablier.Preferably, the means for rotating the hourglass consist of a geared motor communicating a slow rotation movement to a first sleeve of a movable coupling with radial freedom, a second sleeve being integral with a rotation drive shaft hourglass.

Avantageusement, le sablier est monté libre en rotation sur un chariot mobile par l'intermédiaire de galets de roulement sur lesquels il est posé au moyen de bandes de roulement.Advantageously, the hourglass is mounted to rotate freely on a mobile carriage by means of rollers on which it is placed by means of treads.

De préférence, les galets de roulement sont montés sur des boogies articulés disposés deux à deux.Preferably, the rollers are mounted on articulated boogies arranged two by two.

Selon un mode préférentiel de réalisation, l'installation est plus particulièrement constituée de :

  • une enceinte à vide à l'intérieur de laquelle un ensemble mobile supportant en outre le sablier se déplaçant horizontalement par rapport à l'enceinte ;
  • une porte amovible fixée sur le support mobile pour fermer hermétiquement l'enceinte lorsque ledit ensemble mobile est placé à l'intérieur de l'enceinte, l'arbre d'entraînement en rotation traversant cette porte au moyen d'un passage tournant étanche, et sur laquelle le sablier est en appui dans sa position de chargement à l'extérieur de l'enceinte, l'arbre d'entraînement en rotation traversant cette porte au moyen d'un passage tournant étanche ;
  • un réceptacle de déchargement du sablier placé dans la partie inférieure de l'enceinte pour recevoir la poudre traitée issue de la conduite de chargement et de déchargement lorsque le sablier se trouve en position de déchargement à l'intérieur de l'enceinte ;
  • au moins un circuit de mise en dépression de l'enceinte ; et
  • une vanne à vide placée à la sortie du réceptacle de déchargement pour permettre l'isolation des parties amont et aval et l'évacuation sous vide de la poudre vers une trémie de stockage.
According to a preferred embodiment, the installation more particularly consists of:
  • a vacuum enclosure inside which a movable assembly further supporting the hourglass moving horizontally relative to the enclosure;
  • a removable door fixed on the movable support for hermetically closing the enclosure when said movable assembly is placed inside the enclosure, the rotary drive shaft passing through this door by means of a sealed rotary passage, and on which the hourglass is supported in its loading position outside the enclosure, the rotary drive shaft passing through this door by means of a sealed rotary passage;
  • an hourglass unloading receptacle placed in the lower part of the enclosure for receiving the treated powder from the loading and unloading pipe when the hourglass is in the unloading position inside the enclosure;
  • at least one vacuum circuit for the enclosure; and
  • a vacuum valve placed at the outlet of the unloading receptacle to allow the isolation of the upstream and downstream parts and the vacuum evacuation of the powder to a storage hopper.

Selon un autre aspect de l'invention, l'enceinte comprend des appuis inclinés sur lesquels viennent se poser, lors de la translation horizontale de l'ensemble mobile, des deuxièmes galets montés libres en rotation sur une plaque de base placée en-dessous du sablier pour que le sablier prenne appui sur l'enceinte, lorsqu'il se trouve à l'intérieur de celle-ci.According to another aspect of the invention, the enclosure comprises inclined supports on which come to rest, during the horizontal translation of the mobile assembly, second rollers mounted free in rotation on a base plate placed below the hourglass so that the hourglass is supported on the enclosure, when it is inside of it.

L'invention et ses avantages seront mieux compris à la lumière de la description qui suit.The invention and its advantages will be better understood in the light of the description which follows.

Celle-ci est accompagnée de figures représentant respectivement :

  • figures 1A, 1B, 1C et 1D, quatre croquis représentant en coupe le sablier dans quatre positions successives pendant un cycle du procédé selon l'invention ;
  • figure 2, une vue en coupe longitudinale de l'installation selon l'invention ;
  • figure 3, une coupe transversale selon la ligne A-A figurant sur la figure 2, représentant l'installation selon l'invention ;
  • figure 4, un graphique représentant un exemple de cycle de retournement du sablier de l'installation selon l'invention ; et
  • figure 5, deux installations selon l'invention dans une utilisation opérationnelle.
This is accompanied by figures representing respectively:
  • FIGS. 1A, 1B, 1C and 1D, four sketches representing in cross section the hourglass in four successive positions during a cycle of the process according to the invention;
  • Figure 2, a longitudinal sectional view of the installation according to the invention;
  • Figure 3, a cross section along the line AA in Figure 2, showing the installation according to the invention;
  • FIG. 4, a graph showing an example of the hourglass turning cycle of the installation according to the invention; and
  • FIG. 5, two installations according to the invention in operational use.

Le concept principal du procédé selon l'invention consiste à mettre la poudre sous vide, à la brasser lentement tout en élevant sa température (par exemple jusqu'à 600°C, valeur maximale sur l'installation opérationnelle). A cet effet, on utilise un dispositif de séchage et de dégazage, repéré 10 sur toutes les figures et appelé plus communément sablier. Il est constitué d'une paroi 19 de forme très spéciale terminée à ses extrémités d'un flasque.The main concept of the process according to the invention consists in putting the powder under vacuum, in brewing it slowly while raising its temperature (for example up to 600 ° C., maximum value on the operational installation). For this purpose, a drying and degassing device is used, marked 10 in all the figures and more commonly called an hourglass. It consists of a wall 19 of very special shape terminated at its ends by a flange.

Le sablier 10 est mis dans une enceinte à l'intérieur de laquelle on fait le vide jusqu'à 10⁻⁶T (1,333.10⁻⁴ Pa). Le sablier est élevé à une température qui peut dépasser 700°C. Le brassage a lieu dans ces conditions de température et de pression. La température de la poudre est suivie par des thermocouples plongeurs dans les compartiments 4 et 8.The hourglass 10 is placed in an enclosure inside which a vacuum is produced up to 10⁻⁶T (1.333.10⁻⁴ Pa). The hourglass is raised to a temperature that can exceed 700 ° C. Brewing takes place under these temperature and pressure conditions. The powder temperature is followed by immersion thermocouples in compartments 4 and 8.

La figure 1A représente en coupe le sablier dans sa position de chargement de la poudre. Cette dernière n'est pas repérée par une référence numérique sur les figures, mais est schématisée par une ou plusieurs taches de petits points. L'entrée du sablier, constituée par la première extrémité d'un conduit de chargement et de déchargement 2 se trouve, dans cette position, au-dessus du corps du sablier 10, c'est-à-dire dans la position la plus haute qu'elle peut prendre, lors d'une rotation complète du sablier 10. Cette position est utilisée pour canaliser la poudre, destinée à être traitée, à l'intérieur du sablier 10. La poudre tombe par gravité le long de la canalisation de chargement et de déchargement 2 pour arriver dans un premier compartiment 4 qui communique avec la conduite de chargement et de déchargement 2 par sa deuxième extrémité.Figure 1A shows in section the hourglass in its powder loading position. The latter is not identified by a numerical reference in the figures, but is shown diagrammatically by one or more spots of small dots. The hourglass entrance, formed by the first end of a loading and unloading duct 2 is located, in this position, above the body of the hourglass 10, that is to say in the highest position that it can take, during a complete rotation of the hourglass 10. This position is used to channel the powder, intended to be treated, inside the hourglass 10. The powder falls by gravity along the loading and unloading pipe 2 to arrive in a first compartment 4 which communicates with the loading and unloading pipe 2 through its second end.

Une fois que la poudre se trouve dans ce premier compartiment 4, le cycle de brassage peut commencer. Le sablier 10 comporte un deuxième compartiment 8 relié au premier compartiment 4 par l'intermédiaire d'une chicane 6. Les positions relatives des deux compartiments 4 et 8 et leur communication avec la chicane 6 doivent être telles que, dans la position de chargement représentée par la figure 1A, la poudre reste sur une paroi interne 16 du premier compartiment 4 sans pouvoir progresser vers le deuxième compartiment 8.Once the powder is in this first compartment 4, the brewing cycle can begin. The hourglass 10 has a second compartment 8 connected to the first compartment 4 via a baffle 6. The relative positions of the two compartments 4 and 8 and their communication with the baffle 6 must be such that, in the loading position shown in FIG. 1A, the powder remains on an internal wall 16 of the first compartment 4 without being able to progress towards the second compartment 8.

Les parois externes des deux compartiments 4 et 8 et de la chicane 6 sont recouvertes partiellement par des moyens de chauffage 12, qui sont de préférence des plaques chauffantes. Une fois la poudre complètement introduite dans le premier compartiment 4, le sablier 10 est mis en rotation dans un premier sens, symbolisé par la flèche de la figure 1B. Pour la forme de sablier représentée sur ces premières figures, cette rotation est de l'ordre du quart de tour. En effet, dans ce cas, le premier compartiment 4 se trouve au-dessus du deuxième compartiment 8 et la poudre tombe naturellement par gravité dans la chicane 6 et dans le deuxième compartiment 8. Un déflecteur 14 se situe à l'entrée de la chicane 6. Sa fonction est d'empêcher la poudre de retourner directement dans le conduit de chargement et de déchargement 2, lorsque l'on veut la faire tomber dans le deuxième compartiment 8. Sur ces figures, ce déflecteur 14 constitue le prolongement d'une des deux parois du conduit de chargement et de déchargement 2.The outer walls of the two compartments 4 and 8 and of the baffle 6 are partially covered by heating means 12, which are preferably hot plates. Once the powder has been completely introduced into the first compartment 4, the hourglass 10 is rotated in a first direction, symbolized by the arrow in FIG. 1B. For the hourglass shape shown in these first figures, this rotation is of the order of a quarter turn. Indeed, in this case, the first compartment 4 is located above the second compartment 8 and the powder falls naturally by gravity into the baffle 6 and into the second compartment 8. A deflector 14 is located at the entrance to the baffle 6. Its function is to prevent the powder from returning directly to the conduit of loading and unloading 2, when it is desired to drop it into the second compartment 8. In these figures, this deflector 14 constitutes the extension of one of the two walls of the loading and unloading duct 2.

Dans l'exemple représenté ici, la chicane 6 est constituée principalement de deux segments de tubes droits communiquant entre eux par un angle aigu. La chicane 6 communique avec les deux compartiments 4 et 8 en étant orientée de manière à former avec les parois internes 16 et 18 constituant les fonds respectifs des deux compartiments 4 et 8, un angle aigu. Ainsi, la poudre se trouvant dans le premier compartiment 4 doit franchir trois changements brutaux de direction avant de tomber dans le fond du deuxième compartiment 8. Cette forme de réalisation n'est qu'un exemple, toute autre forme de chicane pouvant être employée dès l'instant que le brassage désiré est obtenu.In the example shown here, the baffle 6 mainly consists of two segments of straight tubes communicating with one another at an acute angle. The baffle 6 communicates with the two compartments 4 and 8, being oriented so as to form, with the internal walls 16 and 18 constituting the respective bottoms of the two compartments 4 and 8, an acute angle. Thus, the powder in the first compartment 4 must pass three abrupt changes of direction before falling into the bottom of the second compartment 8. This embodiment is only an example, any other form of baffle can be used from the instant that the desired mixing is obtained.

Pour que la poudre descende complètement dans le deuxième compartiment 8, et surtout pour que le cycle de brassage et de traitement thermique puisse avoir lieu, le sablier 10 est animé de plusieurs lentes rotations successives et inversées. De ce fait, le sablier se trouve lentement secoué et la poudre descend progressivement jusqu'au fond du deuxième compartiment 8 où elle est brassée.In order for the powder to descend completely into the second compartment 8, and above all so that the brewing and heat treatment cycle can take place, the hourglass 10 is driven by several slow successive and reverse rotations. As a result, the hourglass is slowly shaken and the powder gradually descends to the bottom of the second compartment 8 where it is stirred.

En référence à la figure 1C, le cycle se poursuit par un retournement inversé du sablier 10. En effet, la flèche de cette figure 1C indique un sens inversé par rapport au sens symbolisé par la flèche de la figure 1B. Dans la position représentée, un demi-tour complet du sablier 10 a été effectué. Le deuxième compartiment 8 se trouve maintenant au-dessus du premier compartiment 4. La poudre tombe donc naturellement par gravité dans la chicane 6, puis de nouveau dans le premier compartiment 4. De manière analogue, le cycle comprend de préférence, une phase d'agitation analogue à celle ayant lieu lorsque le deuxième compartiment 8 est en bas. Cette agitation avec le premier compartiment 4 placé en bas est toutefois généralement de plus grande amplitude. Il est en effet nécessaire d'assurer la descente complète de toute la poudre se trouvant dans la chicane 6 et dans le deuxième compartiment 8.With reference to FIG. 1C, the cycle continues with an inverted reversal of the hourglass 10. In fact, the arrow in this figure 1C indicates a direction reversed with respect to the direction symbolized by the arrow in FIG. 1B. In the position shown, a complete turn of the hourglass 10 has been made. The second compartment 8 is now located above the first compartment 4. The powder therefore naturally falls by gravity into the baffle 6, then again into the first compartment 4. Similarly, the cycle preferably comprises a phase of agitation similar to that taking place when the second compartment 8 is at the bottom. This agitation with the first compartment 4 placed at the bottom is however generally of greater amplitude. It is indeed necessary to ensure the complete descent of all the powder located in the baffle 6 and in the second compartment 8.

Le nombre de transferts entre les cavités 4 et 8, ainsi que les cycles d'oscillation sont fonction de certains paramètres.The number of transfers between cavities 4 and 8, as well as the oscillation cycles are a function of certain parameters.

Enfin, comme le montre la figure 1D, une ultime rotation dans le même sens d'un quart de tour permet de placer l'entrée du conduit de chargement et de déchargement 2 en-dessous de l'ensemble formé par les deux compartiments 4 et 8 et la chicane 6. De ce fait, la totalité de la poudre revenue dans le premier compartiment 4 tombe dans ce conduit de chargement et de déchargement 2 et peut être réceptionnée en-dessous du sablier 10 par un éventuel réceptacle.Finally, as shown in FIG. 1D, a final rotation in the same direction of a quarter turn makes it possible to place the inlet of the loading and unloading duct 2 below the assembly formed by the two compartments 4 and 8 and the baffle 6. As a result, all of the powder returned to the first compartment 4 falls into this loading and unloading duct 2 and can be received below the hourglass 10 by a possible receptacle.

La figure 2 montre en coupe longitudinale, l'ensemble d'une installation de séchage et de dégazage selon l'invention. Cette dernière comprend principalement l'ensemble constitué du four lui-même, c'est-à-dire l'enceinte à vide 20 et le sablier 10, équipé de ses moyens de mise en rotation qui se trouvent à sa droite. Cet ensemble est monté solidaire sur un chariot 16 mobile en translation horizontale par rapport au sol 18. Le système de translation par vis mère n'est pas représenté ici. L'installation comprend d'autre part, une enceinte 20 fixée par rapport au sol 18 et à l'intérieur de laquelle vient se loger le sablier 10 pour que les opérations de séchage et de dégazage y soient effectuées. Cette enceinte 20 est complétée d'une porte amovible 30, équipée d'un joint 31, montée sur l'ensemble du sablier 10 et du support mobile 16. L'enceinte 20 est également complétée d'un premier orifice de mise en dépression se présentant de préférence sous la forme d'un bouchon 44 rapporté sur les parois de l'enceinte 20, et d'un réceptacle de sortie 52 de la poudre, placé dans la partie inférieure de l'enceinte 20 et débouchant dans une vanne à vide 54.Figure 2 shows in longitudinal section, the assembly of a drying and degassing installation according to the invention. The latter mainly comprises the assembly consisting of the oven itself, that is to say the vacuum chamber 20 and the hourglass 10, equipped with its means of rotation which are located to its right. This assembly is mounted integrally on a carriage 16 movable in horizontal translation relative to the ground 18. The translation system by mother screw is not shown here. The installation further comprises an enclosure 20 fixed relative to the ground 18 and inside which the hourglass 10 is housed so that the drying and degassing operations are carried out there. This enclosure 20 is completed with a removable door 30, fitted with a seal 31, mounted on the assembly of the hourglass 10 and of the movable support 16. The enclosure 20 is also completed with a first depression orifice preferably in the form of a plug 44 attached to the walls of the enclosure 20, and of an outlet receptacle 52 for the powder, placed in the lower part of the enclosure 20 and opening into a vacuum valve 54.

Le chargement en poudre du sablier 10 a lieu lorsque celui-ci est placé en dehors de l'enceinte. Une fois ce chargement effectué, le sablier est introduit à l'intérieur de l'enceinte 20 qui est fermée hermétiquement à l'aide de la porte étanche 30. Celle-ci est montée fixe par rapport au support mobile 16. Le vide est alors fait à l'intérieur de l'enceinte à l'aide d'au moins un circuit de dépression symbolisé par le bouchon 44 placé dans la partie supérieure de l'enceinte 20. En fait, il est préférable d'utiliser un premier circuit primaire pour commencer à faire lentement le vide dans l'enceinte sans aspirer la poudre placée dans le sablier 10. Un deuxième circuit secondaire est ensuite utilisé pour obtenir plus rapidement la dépression désirée.The hourglass 10 is loaded with powder when it is placed outside the enclosure. Once this loading has been carried out, the hourglass is introduced inside the enclosure 20 which is hermetically closed using the watertight door 30. The latter is mounted fixed relative to the mobile support 16. The vacuum is then done inside the enclosure using at least one vacuum circuit symbolized by the plug 44 placed in the upper part of the enclosure 20. In fact, it is preferable to use a first primary circuit to start slowly creating a vacuum in the enclosure without sucking the powder placed in the hourglass 10. A second secondary circuit is then used to obtain the desired vacuum more quickly.

Le sablier 10 et ses moyens d'entraînement en rotation sont montés mobiles en translation sur le chariot 16 pour permettre l'entretien du sablier 10 sans montage ni sans démontage de celui-ci, et le chargement de la poudre dans celui-ci. Toutefois, le procédé de séchage et de dégazage selon l'invention peut être mis en oeuvre avec une installation dans laquelle un trou de chargement serait prévu dans le haut de l'enceinte et dans laquelle le sablier resterait à l'intérieur de l'enceinte. Une telle installation permettrait de supprimer le chariot mobile 16, la porte 30 et son système d'étanchéité et le système de positionnement du sablier à l'intérieur de l'enceinte. Par contre, une telle installation nécessiterait donc une ouverture supplémentaire de chargement prévue dans la partie supérieure de l'enceinte et de revoir les opérations nécessaires à l'entretien.The hourglass 10 and its rotational drive means are mounted movable in translation on the carriage 16 to allow the maintenance of the hourglass 10 without mounting or dismounting thereof, and the loading of the powder therein. However, the drying and degassing method according to the invention can be implemented with an installation in which a loading hole would be provided in the top of the enclosure and in which the hourglass would remain inside the enclosure . Such an installation would make it possible to eliminate the mobile carriage 16, the door 30 and its sealing system and the system for positioning the hourglass inside the enclosure. On the other hand, such an installation would therefore require an additional loading opening provided in the upper part of the enclosure and to review the operations necessary for maintenance.

Les moyens d'entraînement en rotation du sablier 10 se composent d'un motoréducteur 22 fixé sur le chariot mobile 16. Il entraîne un axe d'entraînement 26 du sablier 10, au moyen d'un ensemble de transmission symbolisé en traits interrompus par une courroie 24. Cette dernière entraîne en rotation l'arbre de transmission 26 par l'intermédiaire d'un accouplement mobile à liberté radiale 25 qui est de préférence un joint de OLDHAM. Celui-ci n'est pas dessiné en détail sur la figure 2. Néanmoins, la courroie 24 entraîne un premier manchon de ce joint de OLDHAM, le deuxième manchon de ce joint étant solidaire de l'arbre d'entraînement 26. L'emploi d'un tel joint permettant une légère variation de position en hauteur (quelques millimètres) de l'arbre d'entraînement 26 s'explique par le fait que le sablier 10 doit subir de fortes différences de température entre les différentes phases du procédé et donc une légère dilatation des éléments porteurs du sablier 10. De plus, il doit également subir une légère variation de hauteur dans son positionnement à l'intérieur de l'enceinte 20. En effet, il est nécessaire de mettre le sablier 10 en appui dans l'enceinte 20 durant la totalité du procédé de séchage et de dégazage.The means for driving the hourglass 10 in rotation consist of a geared motor 22 fixed on the movable carriage 16. It drives a drive shaft 26 of the hourglass 10, by means of a transmission assembly symbolized in broken lines by a belt 24. The latter drives in rotation the transmission shaft 26 by means of a movable coupling with radial freedom 25 which is preferably an OLDHAM seal. This is not drawn in detail in the figure 2. Nevertheless, the belt 24 drives a first sleeve of this OLDHAM joint, the second sleeve of this joint being integral with the drive shaft 26. The use of such a joint allowing a slight variation in position in height (a few millimeters) of the drive shaft 26 is explained by the fact that the hourglass 10 must undergo large temperature differences between the different phases of the process and therefore a slight expansion of the bearing elements of the hourglass 10. In addition, it must also undergo a slight variation in height in its positioning inside the enclosure 20. Indeed, it is necessary to put the hourglass 10 in abutment in the enclosure 20 during the entire drying and degassing process .

L'arbre d'entraînement 26 est de préférence creux. Ceci permet le passage de liaison d'alimentation des plaques chauffantes 12 du sablier 10 et d'éventuels thermocouples de contrôle également implantés sur le sablier 10. Cet arbre d'entraînement 26 traverse la porte 30. L'étanchéité est alors assurée par un passage tournant étanche 27 placé autour de l'arbre d'entraînement 26.The drive shaft 26 is preferably hollow. This allows the passage of the feed connection of the heating plates 12 of the hourglass 10 and of possible control thermocouples also located on the hourglass 10. This drive shaft 26 passes through the door 30. The sealing is then ensured by a passage tight turn 27 placed around the drive shaft 26.

Sur la figure 2, l'ensemble mobile du sablier 10 et du chariot mobile 16 est représenté en position intermédiaire, c'est-à-dire que le sablier 10 est à moitié sorti de l'enceinte 20. Dans la position de chargement de la poudre, cet ensemble est complètement sorti de l'enceinte 20. Le sablier 10 est alors monté en porte-à-faux sur le chariot mobile 16. Précisément, il est suspendu au moyen d'un tourillon 34 placé dans au moins une encoche 36 solidaire de la porte 30. Ce tourillon 34 est solidaire du sablier 10 et est placé à la hauteur de la paroi supérieure du tablier 10, à côté du flasque de droite 46 du sablier 10.In FIG. 2, the mobile assembly of the hourglass 10 and the mobile carriage 16 is shown in the intermediate position, that is to say that the hourglass 10 is half out of the enclosure 20. In the loading position of the powder, this assembly is completely removed from the enclosure 20. The hourglass 10 is then mounted in cantilever on the mobile carriage 16. Specifically, it is suspended by means of a journal 34 placed in at least one notch 36 secured to door 30. This pin 34 is integral with the hourglass 10 and is placed at the height of the upper wall of the apron 10, next to the right flange 46 of the hourglass 10.

L'ensemble du sablier 10 s'appuie également sur la porte 30 par des appuis inférieurs 38.The whole hourglass 10 also rests on the door 30 by lower supports 38.

Pour mettre le sablier 10 dans sa position de séchage et de dégazage, l'ensemble mobile est alors translaté vers la gauche de la figure, jusqu'à ce que le sablier 10 prenne la position esquissée en traits mixtes, la porte 30 étant appliquée contre l'extrémité droite de la cuve 20. Cette dernière se trouve donc fermée hermétiquement grâce au joint 31 placé sur la porte 30 et prenant appui sur la face de la cuve 20. Pour placer le sablier 10 en appui dans la cuve 20, cette dernière comprend des appuis inclinés 48 fixés sur son fond et positionnés en correspondance avec des galets de positionnement 50 fixés en-dessous du sablier 10, sur une plaque de base 60, mais libres en rotation autour d'axes horizontaux et faisant ainsi office de roulettes. Lors de la translation du sablier 10, le positionnement relatif des galets de positionnement 50 et des appuis inclinés 48 est tel que chaque galet de positionnement 50 vient tangenter et rouler sur un appui incliné 48. Le sablier 10 se trouve alors légèrement soulevé. La translation de l'ensemble mobile se termine par l'arrivée des galets de positionnement 50 sur une portion horizontale des appuis inclinés 48 correspondant à la position de travail du sablier 10. Ce dernier se trouve alors décroché du crochet de fixation 36 et n'est plus supporté par la porte 30.To put the hourglass 10 in its drying and degassing position, the movable assembly is then translated to the left of the figure, until the hourglass 10 takes the position sketched in dashed lines, the door 30 being applied against the right end of the tank 20. The latter is therefore closed hermetically thanks to the seal 31 placed on the door 30 and bearing on the face of the tank 20. To place the hourglass 10 resting in the tank 20, the latter includes inclined supports 48 fixed on its bottom and positioned in correspondence with positioning rollers 50 fixed below the hourglass 10, on a base plate 60, but free to rotate around horizontal axes and thus acting as rollers. During the translation of the hourglass 10, the relative positioning of the positioning rollers 50 and the inclined supports 48 is such that each positioning roller 50 comes to tangent and roll on an inclined support 48. The hourglass 10 is then slightly raised. The translation of the mobile assembly ends with the arrival of the positioning rollers 50 on a horizontal portion of the inclined supports 48 corresponding to the working position of the hourglass 10. The latter is then unhooked from the fixing hook 36 and n ' is no longer supported by door 30.

En référence à la figure 3, le degré de liberté en rotation horizontale du sablier 10 est assuré par le fait que ce dernier est placé sur des galets de roulement 40 placés à l'extérieur des flasques 46 du sablier 10. Pour faciliter la visualisation de ces galets de roulement 40, la moitié gauche de la figure 3 est une coupe verticale de la figure 2 au niveau de la ligne A-A. Les galets de roulement 40 sont groupés deux par deux au moyen de bras articulés 56 formant ainsi des boogies. Chaque boogie est articulé autour d'un axe horizontal d'articulation 58 solidaire de la plaque de base 60 du sablier 10.With reference to FIG. 3, the degree of freedom in horizontal rotation of the hourglass 10 is ensured by the fact that the latter is placed on rollers 40 placed outside the flanges 46 of the hourglass 10. To facilitate viewing of these rollers 40, the left half of Figure 3 is a vertical section of Figure 2 at the line AA. The rollers 40 are grouped two by two by means of articulated arms 56 thus forming boogies. Each boogie is articulated around a horizontal axis of articulation 58 secured to the base plate 60 of the hourglass 10.

A l'extérieur de chacun des flasques 46 (figure 2), le sablier 10 possède une bande de roulement 42. Chacune d'elles est placée sur au moins deux boogies de galets de roulement 40 placés en correspondance en-dessous d'elles, de telle sorte que le sablier 10 peut tourner librement autour de son axe horizontal car il ne repose que sur des galets de roulement 40.On the outside of each of the flanges 46 (FIG. 2), the hourglass 10 has a tread 42. Each of them is placed on at least two boogies of rolling rollers 40 placed in correspondence below them, so that the hourglass 10 can rotate freely around its horizontal axis because it rests only on rollers 40.

Sur la figure 3 est représenté le bouchon 44 symbolisant les moyens de mise en dépression de l'enceinte 20. Une arrivée d'eau 62 est également représentée sur le haut de l'enceinte 20. Elle est destinée à la circulation d'eau entre les deux parois de l'enceinte 20. La présence de la double paroi de l'enceinte 20 permet une circulation permanente d'eau autour du sablier 10 pour maintenir une température de sécurité sur la surface extérieure de l'enceinte 20.In Figure 3 is shown the cap 44 symbolizing the means of depression of the enclosure 20. A water inlet 62 is also shown on the top of the enclosure 20. It is intended for the circulation of water between the two walls of the enclosure 20. The presence of the double wall of the enclosure 20 allows permanent circulation of water around the hourglass 10 to maintain a safety temperature on the exterior surface of the enclosure 20.

Sur la partie gauche de la figure 3, se trouve une large canalisation 64 permettant à un circuit secondaire de faire le vide dans l'enceinte 20. En dessous de cette dernière est représenté le réceptacle inférieur 52. Un cône de déchargement 66 est également prévu en-dessous du sablier 10, fixé à la base 60 de celui-ci. Ce cône de déchargement 66 permet de guider la poudre à la sortie du sablier 10 dans le réceptacle 52.On the left side of Figure 3, there is a large pipe 64 allowing a secondary circuit to create a vacuum in the enclosure 20. Below the latter is shown the lower receptacle 52. An unloading cone 66 is also provided below the hourglass 10, fixed to the base 60 thereof. This unloading cone 66 guides the powder out of the hourglass 10 into the receptacle 52.

Ce type de montage du sablier 10 sur des galets de roulement 54 permet de limiter les pressions de contact et d'autoriser une légère élévation verticale de l'axe du sablier 10 sans induire de contraintes. L'élévation est due à une variation de diamètre d'appui sur les galets de roulement 40 occasionnée par la dilatation thermique.This type of mounting of the hourglass 10 on rolling rollers 54 makes it possible to limit the contact pressures and to allow a slight vertical elevation of the axis of the hourglass 10 without inducing constraints. The elevation is due to a variation in bearing diameter on the rollers 40 caused by thermal expansion.

Les axes et les galets de roulement 40 sont réalisés de préférence en métaux réfractaires et céramiques pour assurer un fonctionnement dans un environnement ne permettant pas de lubrification des contacts.The axes and the rollers 40 are preferably made of refractory metals and ceramics to ensure operation in an environment which does not allow lubrication of the contacts.

L'utilisation d'une telle installation se fait par le procédé suivant.The use of such an installation is done by the following method.

La première opération consiste à placer la poudre dans le sablier 10, puis à introduire le sablier dans l'enceinte 20. Cette opération est suivie de la mise sous vide de l'intérieur de l'enceinte 20. La poudre est ensuite brassée lentement à l'intérieur du sablier 10 selon un cycle déterminé de retournements du sablier, dont un exemple est donné plus loin. Ce cycle de brassage varie dans de très larges proportions. Le chauffage de la poudre peut être incrémenté par palier ou bien effectué par une montée continue de la température. Après le cycle de brassage, la poudre est refroidie naturellement. Finalement, elle est évacuée du sablier tout en étant maintenue sous vide en vue de son stockage dans une trémie.The first operation consists in placing the powder in the hourglass 10, then in introducing the hourglass into the enclosure 20. This operation is followed by the evacuation of the interior of the enclosure 20. The powder is then stirred slowly at the interior of the hourglass 10 according to a determined cycle of turning the hourglass, an example of which is given below. This brewing cycle varies in very large proportions. The heating of the powder can be incremented in stages or carried out by a continuous rise in temperature. After the brewing cycle, the powder is cooled naturally. Finally, it is evacuated from the hourglass while being kept under vacuum for storage in a hopper.

Le volume de poudre mis en jeu est de préférence de l'ordre de six litres.The volume of powder used is preferably of the order of six liters.

Un exemple de cycle de brassage de la poudre est schématisé sur la figure 4. Le repère 0° correspond à la position de chargement du sablier. La première rotation vers la droite du sablier dépasse les 110°. Le sablier 10 subit alors un nombre déterminé d'oscillations lentes d'amplitude croissante pour atteindre dans certains cas 90°. Le sablier 10 est ensuite retourné de 180° et est à nouveau soumis à des oscillations de plus grandes amplitudes pouvant dépasser 90° et pendant lesquelles la poudre est transférée des cavités 4 à 8 et vice versa.An example of the powder brewing cycle is shown diagrammatically in FIG. 4. The 0 ° mark corresponds to the loading position of the hourglass. The first clockwise rotation of the hourglass exceeds 110 °. The hourglass 10 then undergoes a determined number of slow oscillations of increasing amplitude, in some cases reaching 90 °. The hourglass 10 is then turned 180 ° and is again subjected to oscillations of greater amplitudes which can exceed 90 ° and during which the powder is transferred from the cavities 4 to 8 and vice versa.

Les différentes rotations du sablier sont symbolisées par les flèches en forme d'arc de cercle. Les nombres encerclés affectés à ces flèches sont représentatifs de la chronologie de ces rotations.The different rotations of the hourglass are symbolized by arrows in the shape of an arc of a circle. The circled numbers assigned to these arrows are representative of the chronology of these rotations.

En référence à la figure 5, l'installation est utilisée dans un ensemble de dégazage et de remplissage d'enveloppes pour compactage isostatique à chaud. Sur cette figure, deux installations ont été schématisées. Celle de droite montre un premier sablier 10 enfermé dans une enceinte 20. Cette première installation schématise une opération de dégazage. L'installation de gauche montre un deuxième sablier 10 dans une position de chargement. Ce deuxième sablier 10 est sorti de l'enceinte 20. L'ensemble est placé dans une enceinte de confinement 70 pour permettre d'effectuer les différentes opérations sous atmosphère spéciale, ou pour éviter des problèmes de contamination.Referring to Figure 5, the installation is used in a degassing and envelope filling assembly for hot isostatic compaction. In this figure, two installations have been shown schematically. The one on the right shows a first hourglass 10 enclosed in an enclosure 20. This first installation diagrams a degassing operation. The installation on the left shows a second hourglass 10 in a loading position. This second hourglass 10 is taken out of the enclosure 20. The assembly is placed in a confinement enclosure 70 to allow the various operations to be carried out under a special atmosphere, or to avoid contamination problems.

En dessous de chaque enceinte 20, est placé un réceptacle de sortie 52 pour récupérer la poudre traitée. Ce réceptacle 52 aboutit à une vanne à vide 54. Cette dernière est adaptée pour le transfert de la poudre. En aval de chaque vanne à vide 54 se trouve une trémie 56 dont la contenance correspond à celle des sabliers 10. Chaque trémie 56 est suivie d'un dispositif de convoyage permettant le transfert de la poudre vers une zone d'utilisation. Grâce à la vanne à vide 54, l'ensemble aval est maintenu en atmosphère contrôlée, et plus précisément sous vide, alors que l'enceinte 20 doit être ouverte et le sablier 10 rechargé. A la partie inférieure de chaque trémie 56, se trouve une buse calibrée et amovible. Elle assure l'obturation par accumulation en sortie sur la face supérieure d'un couloir vibrant 58.Below each enclosure 20, an outlet receptacle 52 is placed to collect the treated powder. This receptacle 52 results in a vacuum valve 54. The latter is suitable for transferring the powder. Downstream of each vacuum valve 54 is a hopper 56, the capacity of which corresponds to that of the hourglasses 10. Each hopper 56 is followed by a conveying device allowing the powder to be transferred to a zone of use. Thanks to the vacuum valve 54, the downstream assembly is maintained in a controlled atmosphere, and more specifically under vacuum, while the enclosure 20 must be open and the hourglass 10 recharged. At the bottom of each hopper 56 is a calibrated and removable nozzle. It provides closure by accumulation at the outlet on the upper face of a vibrating passage 58.

Le remplissage est alimenté par deux voies comprenant chacune une enceinte et un sablier. Un dispositif en trident 62 comprend au moins deux branches qui peuvent être isolées du reste de l'équipement par des vannes à vide 54A, 54B. Au centre du trident se trouve un dispositif de contrôle 64 permettant de vérifier le niveau de remplissage de la gaine 67.The filling is supplied by two channels, each comprising an enclosure and an hourglass. A trident device 62 comprises at least two branches which can be isolated from the rest of the equipment by vacuum valves 54A, 54B. In the center of the trident is a control device 64 making it possible to check the filling level of the sheath 67.

La partie comprise entre les vannes 54, 54A et 54B est sous vide en permanence.The part between the valves 54, 54A and 54B is permanently vacuum.

Le remplissage peut s'effectuer de la manière suivante, par exemple pour la voie de gauche :

  • raccordement de la gaine 67 et mise sous vide par un circuit raccordé au trident (non représenté) ;
  • ouverture de la vanne 54 ;
  • transfert de la poudre du sablier dans la trémie 56 ;
  • fermeture de la vanne 54 (rechargement du sablier possible) ;
  • ouverture de la vanne 54A ;
  • mise en route du couloir vibrant 58 ;
  • suivi du niveau dans la gaine par 64 ;
  • arrêt du couloir vibrant 58 ;
  • fermeture de la vanne 54A.
Filling can be carried out as follows, for example for the left lane:
  • connection of the sheath 67 and evacuation by a circuit connected to the trident (not shown);
  • opening the valve 54;
  • transfer of the powder from the hourglass into the hopper 56;
  • closing valve 54 (recharging the hourglass possible);
  • opening of valve 54A;
  • start-up of the vibrating corridor 58;
  • level monitoring in the sheath by 64;
  • stopping the vibrating passage 58;
  • valve 54A closed.

La gaine 67 est ensuite obturée par un appareil de sertissage et de soudage non représenté ici.The sheath 67 is then closed by a crimping and welding device not shown here.

L'utilisation de deux voies de séchage et de dégazage permet de remédier à un éventuel manque de poudre sur l'une des deux voies au cours du remplissage.The use of two drying and degassing routes makes it possible to remedy a possible lack of powder on one of the two routes during filling.

L'ensemble de l'installation peut être piloté par un automate programmable qui gère le cycle de traitement de la poudre. Ce dernier comprend un vidage primaire lent, puis la aise sous vide secondaire, le chauffage et les rotations du sablier. Cet automate programmable peut également gérer les sécurités associées aux fonctions vide, température et ouverture des vannes.The entire installation can be controlled by a programmable controller which manages the powder treatment cycle. The latter includes a slow primary emptying, then the ease of secondary vacuum, heating and the hourglass rotations. This programmable controller can also manage the safety associated with the vacuum, temperature and valve opening functions.

L'ensemble décrit sur la figure 5 n'est qu'un exemple d'utilisation de l'installation selon l'invention. On peut en effet envisager d'autres montages possibles utilisant des voies multiples disposées par exemple en carrousel.The assembly described in FIG. 5 is only an example of use of the installation according to the invention. We can indeed consider other possible assemblies using multiple channels arranged for example in a carousel.

On peut également envisager le chargement direct du sablier dans l'enceinte en prévoyant une issue supplémentaire dans la partie supérieure de l'enceinte.One can also consider the direct loading of the hourglass in the enclosure by providing an additional outlet in the upper part of the enclosure.

Le traitement de la poudre peut également être effectué sous atmosphère contrôlée ou en atmosphère réactive. Un montage en boîte à gants peut même être envisagé pour le traitement de produits toxiques.The treatment of the powder can also be carried out under a controlled atmosphere or in a reactive atmosphere. Glove box mounting can even be considered for the treatment of toxic products.

L'ensemble décrit par la figure 5 est particulièrement prévu pour l'encapsulation sous vide de poudre destinée à une densification par pressage isostatique à chaud.The assembly described in FIG. 5 is particularly intended for vacuum encapsulation of powder intended for densification by hot isostatic pressing.

Le choix des matériaux peut rendre l'installation compatible avec des produits pharmaceutiques ou alimentaires par exemple.The choice of materials can make the installation compatible with pharmaceutical or food products for example.

Claims (9)

  1. Process for drying and degassing powders, comprising the following stages:
    - charging the powder into a drying and degassing device called a "riffler' (10);
    - producing a relative vacuum in the riffler (10);
    - heating the interior of the riffler to a temperature enabling a temperature of 600°C to be reached in the powder and, simultaneously, very slowly stirring the powder inside the riffler (10) according to a determined cycle of inversions of the riffler (10);
    - cooling the interior of the riffler (10); and
    - emptying the riffler (10) of the processed powder while keeping this powder stored under vacuum.
  2. Process according to Claim 1, the riffler (10) comprising at least two compartments (4, 8) communicating with each other by means of a chicane (6), characterized in that the stirring of the powder is performed by slow inversion of the riffler (10) in a first direction to make the powder flow gradually from the first compartment (4) towards the second compartment (8), and then by slow inversion of the riffler (10) in a second direction opposite to the first direction to make the powder return into the first compartment (4).
  3. Process according to Claim 2, characterized in that the cycle of inversions of the riffler (10) comprises at least one series of oscillations about its horizontal axis to promote the stirring and the flow of the powder from one compartment to the other.
  4. Plant for making use of the process according to any one of the preceding claims, characterized in that it comprises:
    - a device for drying and degassing, called "riffler" (10) mounted rotating about a horizontal axis, comprising:
    - a conduit for charging and discharging (2) communicating with:
    - a first compartment (4) communicating furthermore with:
    - a chicane (6) itself communicating with:
    - a second compartment (8),
    the conduit for charging and discharging (2) and the chicane (6) opening into the first compartment (4) so that, in the case of a first series of angular positions of the riffler (10), the powder introduced into the conduit for charging and discharging (2), or coming from the second compartment (2), falls and remains owing to gravity in the first compartment (4), the chicane (6) opening into the second compartment (8) so that, in the case of a second series of angular positions of the riffler (10), which are different from the positions of the first series, the powder coming from the first compartment (4) falls gradually and remains in the second compartment (8), the angular difference of the two series of angular positions corresponding to the rotations of the riffler (10),
    - means for heating (12) the riffler (10);
    - means for rotating the riffler (10); and
    - means (54, 54A, 54B) for applying vacuum to the riffler (10) and for keeping the stored powder under vacuum.
  5. Plant according to Claim 4, characterized in that the means for heating the inside of the riffler (10) are heating plates (12) placed outside the compartments (4, 8) and the chicane (6).
  6. Plant according to Claim 4 or 5, characterized in that the means for rotating the riffler (10) consists of a geared motor (22) imparting a movement of slow rotation to a first sleeve of a movable coupling with radial freedom (25), the second sleeve being integrally attached to a shaft (26) for driving the riffler (10) in rotation.
  7. Plant according to any one of Claims 4 to 6, characterized in that the riffler (10) is mounted free in rotation on a movable trolley (16) by means of first running rollers (40) on which it is placed by means of two running strips (42).
  8. Plant according to Claims 6 and 7, characterized in that it comprises:
    - a vacuum vessel (20) inside which the whole of the movable trolley (16) and of the riffler (10) enters by horizontal translation;
    - a removable door (30) fastened to the movable support (16) to close the vessel (20) hermetically when the whole of the movable trolley (16) and the riffler (10) is placed inside the vessel (20), the shaft (26) for driving in rotation passing through the door (30) by means of a leakproof rotating passage (27) and on which door the riffler (10) bears in its charging position outside the vessel (20);
    - a receptacle (52) for discharging the riffler, placed in the lower part of the vessel (20) to receive the processed powder emerging from the conduit (2) for discharging the riffler (10) when the latter is in a discharging position and inside the vessel (20);
    - at least one circuit for producing a partial vacuum (44) in the vessel (20); and
    - a vacuum valve (54) placed at the exit of the discharging receptacle (52) to permit the isolation of the parts placed upstream and downstream and the removal of the powder under vacuum towards a storage hopper (56).
  9. Plant according to Claim 8, characterized in that the vessel comprises inclined supports (48) on which, during the horizontal translation of the whole of the movable trolley (16) and of the riffler (10), second positioning rollers (50) which are mounted free in rotation below the riffler (10) are placed in order that the latter may bear on the vessel (20) when it is inside the latter.
EP91400894A 1990-04-03 1991-04-02 Process and apparatus for drying and degassing powders Expired - Lifetime EP0451048B1 (en)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
FR9004254A FR2660423B1 (en) 1990-04-03 1990-04-03 METHOD AND PLANT FOR DRYING AND DEGASSING POWDERS.
FR9004254 1990-04-03

Publications (2)

Publication Number Publication Date
EP0451048A1 EP0451048A1 (en) 1991-10-09
EP0451048B1 true EP0451048B1 (en) 1994-06-29

Family

ID=9395402

Family Applications (1)

Application Number Title Priority Date Filing Date
EP91400894A Expired - Lifetime EP0451048B1 (en) 1990-04-03 1991-04-02 Process and apparatus for drying and degassing powders

Country Status (4)

Country Link
EP (1) EP0451048B1 (en)
AT (1) ATE108015T1 (en)
DE (1) DE69102666T2 (en)
FR (1) FR2660423B1 (en)

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN107485559A (en) * 2017-09-21 2017-12-19 仲杏英 Powder dries access boxes

Families Citing this family (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
FR2839145B1 (en) * 2002-04-30 2004-07-02 Hivert Systemes Automatises PROCESS FOR VACUUM DRYING OF A FACTORY PART AND INSTALLATION
US8357251B2 (en) * 2010-07-30 2013-01-22 United Technologies Corporation Powder processing method
CN109556374B (en) * 2018-12-29 2023-12-19 钟山县洲星食品有限公司 Fern powder drying device

Family Cites Families (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
GB191509971A (en) * 1915-07-08 1916-05-04 Elias Djandiery Improvements in Grain Drying Apparatus.
FR1002719A (en) * 1949-12-10 1952-03-10 Vacuum dryer improvements
US3280470A (en) * 1964-07-23 1966-10-25 Robert L Kuntz Method and apparatus for oven dehydrating compounds
US3599709A (en) * 1970-04-02 1971-08-17 Patterson Kelley Co Heat exchange mill
HU184672B (en) * 1979-03-21 1984-09-28 Richter Gedeon Vegyeszet Apparatus for handling wet solid materials, preferably pasty materials with heating or cooling

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN107485559A (en) * 2017-09-21 2017-12-19 仲杏英 Powder dries access boxes
CN107485559B (en) * 2017-09-21 2020-06-09 莱芜职业技术学院 Powder drying storage box

Also Published As

Publication number Publication date
DE69102666D1 (en) 1994-08-04
FR2660423B1 (en) 1992-06-12
DE69102666T2 (en) 1995-01-12
ATE108015T1 (en) 1994-07-15
EP0451048A1 (en) 1991-10-09
FR2660423A1 (en) 1991-10-04

Similar Documents

Publication Publication Date Title
EP0619254B1 (en) Apparatus and method for transferring products flowing by gravity
EP0227789A1 (en) Automatic dispenser of heated food, especially cooked french fries
EP0196486A1 (en) Charging apparatus for a shaft furnace
FR2964091A1 (en) DEVICE FOR HANDLING FUTS, TRANSFER PLANT FOR POWDER MATERIAL, AND TRANSFER METHOD
FR2695464A1 (en) Closed induction furnace for melting and casting.
EP0451048B1 (en) Process and apparatus for drying and degassing powders
EP0514526B1 (en) Facility for producing molten metal in an electric furnace
FR2821775A1 (en) MOLDING APPARATUS WITH MOUNTING MANEUVER AND MOLD PLACEMENT
EP0030481A1 (en) Weigher for pasty materials such as bread dough, and kneader-mixer-weigher equipped with such a weigher
EP1129221A1 (en) Device for dispensing bulk materials
EP0414601B1 (en) Apparatus for filling a tubular blank with powder
FR2933594A1 (en) THERMAL TREATMENT TANK
CH364212A (en) Multiple station machine for canning
WO2012085422A1 (en) Heating module, heating system including a plurality of heating modules, and facility including such a heating system
BE519656A (en)
EP0172854A1 (en) Process for the treatment by bulk agitation of rough castings or machined parts and machine for implementing such process.
FR2829711A1 (en) Horizontal drum machine for treatment of industrial parts comprises drum, able to rotate in two directions, with permanently open filling opening and internal endless screw extending into emptying opening
WO2022258914A1 (en) Device for feeding a container for an installation for the heat treatment of waste
CH410029A (en) Process for tempering timepieces and apparatus for implementing this process
EP0477117B1 (en) Modular flexible thermic treatment device
FR2497442A1 (en) Pressure steam peeling machine for fruit and vegetables - tumbles prod. in rotary basket which diffuses steam uniformly to reduce peeling time
BE466339A (en)
BE532248A (en)
FR2571361A1 (en) Process and plant for the manufacture of fragmented expanded slag
FR2670217A1 (en) Plant for the production of steel by melting iron scrap

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): AT CH DE GB IT LI SE

17P Request for examination filed

Effective date: 19920311

17Q First examination report despatched

Effective date: 19930709

GRAA (expected) grant

Free format text: ORIGINAL CODE: 0009210

AK Designated contracting states

Kind code of ref document: B1

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

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 FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT;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: 19940629

REF Corresponds to:

Ref document number: 108015

Country of ref document: AT

Date of ref document: 19940715

Kind code of ref document: T

REF Corresponds to:

Ref document number: 69102666

Country of ref document: DE

Date of ref document: 19940804

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

Ref country code: SE

Effective date: 19940929

GBT Gb: translation of ep patent filed (gb section 77(6)(a)/1977)

Effective date: 19941005

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

Ref country code: DE

Payment date: 19950411

Year of fee payment: 5

Ref country code: GB

Payment date: 19950411

Year of fee payment: 5

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

Ref country code: AT

Payment date: 19950413

Year of fee payment: 5

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

Ref country code: CH

Payment date: 19950427

Year of fee payment: 5

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

Ref country code: GB

Effective date: 19960402

Ref country code: AT

Effective date: 19960402

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

Ref country code: LI

Effective date: 19960430

Ref country code: CH

Effective date: 19960430

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

Effective date: 19960402

REG Reference to a national code

Ref country code: CH

Ref legal event code: PL

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

Ref country code: DE

Effective date: 19970101