EP0935111B1 - Process and apparatus for drying soft biopolymer capsules, in particular soft gelatin capsules - Google Patents

Description

The invention relates to a method and an apparatus for Drying capsules made of a biopolymer, in particular Soft gelatin capsules, according to the generic term of the independent Claims 1 and 3, respectively.

Capsules made of biopolymer material come in different Areas needed, especially in the pharmaceutical industry, in Food area etc. The capsules contain depending on the Manufacturing method immediately after the encapsulation of the Ingredient has a relatively high moisture content and must therefore be subjected to a drying process. This applies particularly to the Rotary-Die method, in which two endless gelatin tapes in the gusset of two form rollers be brought together. Obtained between these form rollers the capsules are their outer contour after the filling process however not yet dimensionally stable. The capsules were previously in a pre - dried tumbler consisting of a rotating and perforated drum. Through the perforated Drum wall is tempered (18 - 35 ° C) drying air blown until the capsule shell reaches the desired one Has moisture content. The final drying takes place then in tumblers or without moving the capsules on drying surfaces or drying belts. Such one Drying process is for example in US-A-5,200,191 described.

Methods and devices for drying bulk goods such as e.g. Grains and the like are in a drying tube well known and in use for a long time. For example, the FR-A 550 717 a dryer with a rotary drive stored tube through which the drying material is continuous is feasible from the inlet to the outlet, in countercurrent Desiccant is carried through the tube. The Dried goods are retained in a collection chamber and at the end of the drying process through the side of the drum taken.

FR-A 1 102 740 describes a method for simultaneous drying and cleaning of grain products. The grain is slanted at the open end of a provided drying tube introduced. Using shovels the inner wall is constantly mixed Grain. At the same time, the drum can be viewed from the outside forth be heated with a heater. drying air is blown through the drum with the help of a fan.

A major disadvantage of these known methods is in that a continuous drying process is not is possible. While the capsule production is continuous or can be done in very short cycle times, must be discontinuous be dried, taking the dimension of the tumbler constructive limits are set. In addition, the Cleaning the perforated tumbler drums is complex and that Movement behavior of the capsules is during operation of the tumbler uncontrollable. It is therefore an object of the invention a method or an apparatus of the aforementioned Way to create capsules continuously and gently to be able to dry. The drying process should do this have a positive effect on the shape of the capsules and the The device is said to be easy to clean or easy to clean Batches can be converted. Finally, with the existing one Desiccant achieved the highest possible efficiency become.

From a procedural point of view, this task is performed with a Method according to claim 1 and in device Regarded solved with a device according to claim 3. The Drying tube rotating about its longitudinal axis also supports With the help of the mechanical conveying means arranged therein Capsules continuously from an inlet side to an outlet side. The drying tube can thus be constantly fresh Capsules are loaded. The drying agent, preferably tempered, dried air, is in cocurrent or countercurrent to the capsules in the longitudinal direction through the Pipe led. This not only ensures a large inflow area on the capsules, but also allows one closed air flow and optimal energy evaluation.

The means of funding is advantageously a continuous one Auger. In this way, a specific one Capsule quantity screwed forward between two flights of the screw and kept moving gently. Instead of the screw conveyor could also individual feed blades be arranged on the inner pipe jacket. The pipe jacket is closed so that the capsules on a smooth as possible Unroll the surface and the drying agent is not between both pipe ends can escape.

A particularly inexpensive and lightweight construction results, if the drying tube and preferably also the screw conveyor consist of plastic material. Plastic pipes are as finished products in different diameters and Qualities available and can be easily edited and handle. For example, the screw conveyor can also formed by a web of plastic material be welded to the inner wall of the drying tube becomes.

The tube jacket of the drying tube can be at least one have closable opening through which the inside is easily accessible for cleaning purposes. If the lid this opening is made of transparent material also observe the material flow in the company.

The drying tube can be on one of several storage rolls existing bearing block, of which at least one is connected to a drive device. The pipe is thus stored loosely and can be lifted out at any time. To increase the lateral stability, the outer jacket of the Drying tube track grooves are provided, in which the Intervene bearing rollers.

The drying agent is rigid and coaxial to the Axis of rotation of the drying pipe arranged pipe socket fed and / or discharged to one end of the drying tube. This will make the system as closed as possible achieved that the end of the drying tube with one each Pipe socket comprehensive cover is closed, on the Circumferential area a preferably circular segment-like opening is arranged that the pipe socket with a rigid, Provide faceplate running parallel to the cover which corresponds to the opening in the lid Area, leaving the aperture in the course of a Rotation of the drying tube the opening in the lid for the Temporarily releases the supply or for the removal of capsules. This opening is preferably on the end or matched to the start of the screw conveyor.

Because the maximum possible length of a drying tube For various reasons, the capsules are beneficial passed through several similar drying tubes, connected in series. The drying agent can pass through the pipes in a closed system be performed. A particularly space-saving arrangement results if there are several drying tubes of the same type on a rack are arranged at different levels and if the outlet side for the passage of the capsules a higher drying tube with the inlet side of a deeper drying tube is connected. With drying pipes of more than 2 m in length and more than 0.3 m in inner diameter good results have been achieved. In an experimental setup the drying pipes were 4 m long and one Inner pipe diameter of 0.48 m. The screw conveyor ordered over 34 aisles with a gradient of approx. 12 cm. The material web the screw conveyor had a wall thickness of 2 mm. Baffles can still occur between the screw turns be arranged for the mixing of the capsules.

The described method and the described device are also particularly suitable for drying spherical Capsules because every single capsule in the drying tube covers a relatively long taxiway. The spherical shape will so that with increasing drying it will be maintained even any existing deviations in the plastic Condition even balanced afterwards.

Figur 1

eine Seitenansicht auf eine Anordnung bestehend aus zwei miteinander verbundenen Trocknungsrohren,

Figur 2

ein Detail der Einspeisung für das Trocknungsmittel gemäss Figur 1,

Figur 3

eine Ansicht aus Pfeilrichtung A gemäss Figur 2,

Figur 4

die Ansicht gemäss Figur 3 nach einer Rohrdrehung von 30 Grad,

Figur 5

eine schematische Darstellung einer Lagerung eines Trocknungsrohrs,

Figur 6

die perspektivische Darstellung einer Reinigungsöffnung in einem Trocknungsrohr, und

Figur 7

die perspektivische Darstellung einer Anordnung mit mehreren versetzt übereinander angeordneten Trocknungsrohren.

Embodiments of the invention are shown in the drawings and are described in more detail below. Show it:

Figure 1

a side view of an arrangement consisting of two interconnected drying tubes,

Figure 2

3 shows a detail of the feed for the drying agent according to FIG. 1,

Figure 3

2 shows a view from arrow direction A according to FIG. 2,

Figure 4

3 after a tube rotation of 30 degrees,

Figure 5

a schematic representation of a storage of a drying tube,

Figure 6

the perspective view of a cleaning opening in a drying tube, and

Figure 7

the perspective view of an arrangement with several staggered drying tubes.

As shown in Figure 1, there is an arrangement for drying of capsules from the two separate drying tubes 1a and 1b. The drying tube 1a is about a horizontal longitudinal axis rotatably driven. The drying tube is 1b parallel to the drying tube 1a, but a little lower, its longitudinal axis being inclined by approximately 5 degrees to the horizontal is. With this arrangement, a low filling level and achieved a relatively increased emptying height, which makes handling facilitated. The tubes could also both be horizontal be stored. Both drying tubes are on storage rolls 8, which are each arranged in pairs. The inlet side for the drying tube 1a is not visible in FIG. 1, however its outlet side 3 lies directly above the inlet side 2 of the lower drying tube 1b.

The capsules move in the direction of arrow a, making the transition into the lower drying tube 1b via a fixed connecting line 16 takes place. This protrudes into a conical one Inlet nozzle 22, which is arranged at the pipe end. Of the Inlet side 2 of the lower drying tube 1b Capsules against the inclination to the outlet side, not shown promoted.

In each drying tube there is a screw conveyor on the inner wall 5 arranged, the worm gear having an inner diameter Si has. The jacket of each drying tube has preferably at least two openings 6, as in FIG. 6 shown. The lid 7 for this opening is under the curved the same radius as the pipe jacket. The lid will advantageously fastened to the pipe jacket with quick-release means. Of course, the screw conveyor 5 is also over guided the area of the opening 6, but not there with the Cover 7 connected.

The supply of gaseous drying agent 4 takes place in the Embodiment through a pipe socket 9, which has a certain distance protrudes into the drying tube la and the is rigidly arranged relative to this. Evidently the inside diameter Si of the screw conveyor 5 is slight larger than the outside diameter of the connector 9. A fan 10 serves as the supply source Pipe socket 9 is connected.

The end of a drying tube and its function is then explained with reference to Figures 2 to 4. The The tube end is closed with a pot-like cover 11, which is connected laterally with screws 19 to the pipe jacket is. The lid closes with a sealing collar 18 around the rigid pipe socket 9. At its peripheral area the cover 11 has an opening 12 in the form of a segment of a circle.

On the inside of the cover is on the rigid pipe socket 9 an aperture 13 by means of a retaining collar 17 rotatably attached. A remains between the cover 11 and the cover 13 Air gap to avoid friction. The aperture 13 has an opening area 14 which is in a certain Relative position according to Figure 3 is congruent with the Opening 12 in the lid 11. The aperture 13 has the task of Close opening 12 over most of the turning range.

If the drying tube starts from the largest possible 3 turns in the direction of arrow b, the lid opening 12 is covered more and more and last completely closed. This temporary exposure of the face of the drying tube is sufficient to the between to discharge capsules lying in two screw flights. On the the capsules can also be used in an intermittent manner exposed opening in the drying tube become. The desiccant outflow made possible is negligible.

Figure 5 shows schematically the storage of a drying tube la between two bearing rollers 8, 8 ', the roller 8' over a toothed belt or flat belt 21 with a drive wheel 20 connected is. The bearing rollers can be in a track groove be guided so that an inclined pipe is not can slide sideways. Since the drying tube no more Has connection to the frame 15, it can be particularly easy be lifted out.

Finally, FIG. 7 shows an arrangement with several Drying pipes 1a to 1x, the side and height offset in a boom frame 15 rotatably mounted are. The drying tubes are connected in series, so that in a relatively small space a relatively large one Total length for drying is achieved. The capsules are fed on the inlet side 2 of the top drying tube 1a and on the outlet side 3 of the lowest drying tube Removed once. The connection of the individual pipes takes place via inclined connecting lines, similar to Figure 1. The drying air can also via rigid pipe sockets from one drying pipe to the next. The Sealing on the end faces is also the same or similar to Figure 1. But one would also be conceivable Parallel connection of the pipes with regard to the passage the drying air.

Claims (10)

1. Method for drying soft capsules of a biopolymer, in particular soft gelatine capsules, in which the capsules are subjected, in a hollow body that rotates around its longitudinal axis, to a gaseous drying agent,
   characterised in that

   on an inlet side (2), the capsules are supplied to at least one drying pipe (1a) that rotates with a closed pipe casing and with a smooth surface on the inner side, wherein the hollow body is the drying pipe,

   the capsules are conveyed by means of mechanical conveyors on the inside of the pipe casing continuously from the inlet side (2) to an outlet side (3), over a length of at least 2 metres,

   and at the outlet side (3) they are taken out of the drying pipe through an opening (12) that is released intermittently,

   wherein the drying agent (4) is supplied through the pipe in co-current flow, or in counter-current flow.
2. Method in accordance with claim 1, characterised in that the capsules are guided through several rotating drying pipes (1a, 1b) which are connected to one another in series, and that the drying agent (4) can be guided in a longitudinal direction through the drying pipe.
3. Device for drying soft capsules of a biopolymer, in particular soft gelatine capsules, with a hollow body (1a) which is home such that it can be driven to rotate around its longitudinal axis, for receiving the capsules, and with a supply source for supplying a gaseous drying agent (4) into the hollow body,
   characterised in that

   the hollow body is at least one drying pipe (1a) with a closed pipe casing and with a smooth surface on the inside of at least 2 metres in length,

   arranged on its inner wall are means for continuous conveyance of the capsules from an inlet side (2) to an outlet side,

   the drying agent can be supplied or removed via a rigid socket piece (9) that is arranged coaxially to the rotational axis of the drying pipe, at one end of the drying pipe,

   that one end of the drying pipe is closed off with a cover (11) which encloses the socket piece, and which has arranged on its peripheral area an opening (12) which is preferably in the form of a circular segment,

   that the socket piece (9) is equipped with a rigid screen (13) which runs plane-parallel to the cover (11), and which releases an area that corresponds to the opening (12) in the cover,

   wherein in the course of a rotation of the drying pipe, the screen (13) temporarily releases the opening in the cover, for the supply and/or removal of capsules.
4. Device in accordance with claim 3, characterised in that the means for conveying the capsules is a spiral conveyor (5).
5. Device in accordance with claim 4, characterised in that the drying pipe (1a) and the spiral conveyor (5) comprise synthetic material and that the spiral conveyor is welded to the inner wall of the pipe casing.
6. Device in accordance with one of the claims 3 to 5, characterised in that the pipe casing has at least one opening (6) that can be closed off.
7. Device in accordance with one of the claims 3 to 6, characterised in that the drying pipe rests on several bearing rollers (8), at least one of which is connected to a drive device.
8. Device in accordance with one of the claims 3 to 7, characterised in that arranged on a frame (15), at different levels, are several drying pipes (1a, 1b) of the same type, and that in each case, for guiding the capsules through, the outlet side of a higher drying pipe is connected to the inlet side of a lower drying pipe.
9. Device in accordance with one of the claims 3 to 8, characterised in that the drying pipe has an internal pipe diameter of more than 0.3 metres.
10. Device in accordance with claim 3 and claim 4, characterised in that the spiral conveyor (5) has a continuous spiral wing which is formed by a material web, and whose internal diameter is greater than the outer diameter of the socket piece.

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