FR2882663A1 - Spherical granule maker, e.g. for pharmaceutical or food products, has extruder with single compression screw and segments of variable pitch and direction - Google Patents

Abstract

The granule maker, comprising a hopper (9), an extruder with a rotating screw inside a sleeve (4), a die (6) and cutter (7), has the screw made up of threaded segments (1, 2, 3) of variable pitch, with at least one segment having a reverse thread. The extruder sleeve also has one or more nozzles (11, 12) for injecting liquids, linked to a regulator that controls the amount of liquid injected, or to a liquid container via a pump with a variable flow rate and pressure. The reverse threaded segment of the screw is located after the last injection nozzle. The hopper, which delivers powdered material, is connected to the extruder via a delivery regulator (10).

Description

Apparatus and process for producing granules

  The present invention relates firstly to an apparatus for producing granules containing at least one concentrated active ingredient, for example a plant ingredient, mixed with one or more substances, in particular adsorbent and / or absorbent, and secondly a method of manufacturing such granules. granules.

  This dual invention is based on the extrusion of a pulverulent and pasty material obtained by mixing a pulverulent material containing at least one substance having a capacity to adsorb and / or absorb predetermined amounts of liquid and a liquid material containing at least one concentrated active ingredient.

  The extrusion is done using a screw device pushing the material under a certain pressure in the direction of a die with a multitude of orifices, for example cylindrical small diameters, producing continuous filaments of dough, which are then cut at regular intervals to finally give extrudates in the form of small filaments of reduced length.

  These filamentous extrudates are then spheronized, that is to say transformed by rotation into small spheres (the granules) in a container provided for this purpose.

  The rotation and the hygrometry contribute to give a spherical shape to the extrudates or agglomerates.

  The spherical agglomerates are then dried, for example by supplying hot, dry air into a container so as to create an atmosphere suitable for dehumidifying them after the spheronization step.

  The object of the present invention is to enable the production of granules whose measurement of the concentration of active ingredient is easily controlled over a wide range up to very high concentrations never obtained so far in microgranules. The apparatus and method of the invention are therefore designed so that they can operate with extracts whose concentration of active ingredients can be increased to values which exclude the use in particular of liquid extracts simply obtained by dissolution aqueous, alcoholic or hydroalcoholic, which do not allow to achieve the concentrations of the invention. This allows in fact to use concentrated extracts which are close to soft or firm extracts, according to the definition of the French pharmacopoeia, that is to say more viscous liquids than liquid extracts, whose hydraulic characteristics are obviously an influence on the economics of the process and on the corresponding design of the apparatus. The extracts used have a dry residue which can be up to 650/0 m / m.

  2882663 2 The control of concentrations, especially for high values, is incomparable with that which could be implemented with liquid extracts, since it is now possible to work with concentrations of the order of two to three times higher or even higher than those previously used in processes based on such extracts.

  For this purpose, the apparatus of the invention comprises a feed hopper, a screw extruder surrounded by a sheath, a die disposed at the outlet of the extruder, a device for cutting the extrudates produced by the die, a spheronization device of the extrudates and a drying device of the granules thus formed, and it is characterized as essential in that: - the extruder is modular and single-screw; the extrusion screw consists of threaded modules with variable pitch placed end to end, of which at least one module is an inverted thread; the extruder is provided, downstream of the hopper, with at least one liquid injection nozzle associated with a device for regulating the quantity of liquid injected.

  The apparatus of the invention therefore produces a first extrusion phase on an exclusively powdery material, mixing with the liquid, the viscosity of which depends on the type and concentration of extract used, occurring only downstream of the distribution. of pulverulent material. The amount of liquid extract injected depends on the desired active ingredient content in the granules to be produced relative to the concentration of the extract contained in the injected product.

  Given the modularity conferred on the extruder, resulting from the assembly of threaded modules with variable pitch according to the use, it is possible to easily modify the parameters of the extrusion including playing on the step of the modules in depending on their position on the rotary extrusion shaft. The choice is made according to the intended application.

  The liquid mixture / pulverulent material is carried out during the extrusion for reasons including mechanical operation of the whole: the viscosity of the extract used would not allow to achieve the correct mixture at the feed, which would then become problematic as much in its mechanical realization as for the regulation of the quantity supplied.

  According to one possible configuration, the extruder is provided with two liquid injection nozzles, arranged at two axially distinct points of the extruder.

  One can be used to inject concentrated extract into active ingredient whereas the other one, which is positioned further downstream, can be used to inject a neutral liquid (water and / or alcohol) used to correct the desired concentration, if the amount of liquid extract injected at the first point, depending on the desired active ingredient content in the granules, is incorrectly regulated. Alternatively, a second nozzle can reinject concentrated extract, in order to further increase the concentration in the granules or to introduce another active ingredient, and a third can then be responsible for injection into neutral liquid. Many injection options are possible.

  It should be noted that the very configuration of the invention is part of the desire to optimize control of the concentration in that the extrusion of a dry mass upstream of the addition of liquid confers on the screw a function of regulation of the quantity of material at the level of the injections, appreciably improving the accuracy of the measurements.

  Knowing that regulation is also already provided upstream, since the feed hopper is connected to the extruder via a device for regulating the amount of pulverulent material, it can be considered that the control of the proportions is real.

  The injection is itself regulated, and each liquid injection nozzle is connected for this purpose to a reservoir of said liquid via a pump whose flow and pressure are adjustable.

  The extrusion shaft consists of screw modules whose steps are in practice different from one place to another, to optimize the various functions provided by the screw. Thus, in particular, the pitch of the threading is reduced in the vicinity of the first injection nozzle. In the upstream portion, on the portion of the extrusion shaft responsible for conveying an exclusively powdery material, the thread pitch is chosen such that so that the extrusion pressure is not too high, the purpose being at this stage mainly to convey the material by controlling the amount of powder supplied at the time of mixing.

  The module (s) constituting a portion of the inverted-screw extrusion shaft are arranged downstream of the last injection nozzle, where the proportioned mixture is in principle already made.

  Between these two portions, in the vicinity of the first injection nozzle, the extrusion shaft therefore consists of at least one threaded module with a finer pitch because, as will be explained in more detail below with reference to FIG. method of manufacturing the granules, a thermal flash for better fixing the active ingredients on the adsorbent and / or absorbent substrate is sought in the context of the present invention. However, a decrease in the thread pitch of the extrusion shaft causes an increase in the pressure and therefore the temperature.

  At least a portion of the sleeve surrounding the extrusion screw may furthermore, according to the invention, be provided with additional heating means. These 2882663 4 may for example consist of resistances traversed by an electric current and embedded in the sleeve, and be arranged downstream of the first injection nozzle.

  The goal is to obtain a temperature exceeding 70 C in the sheath.

  Preferably, a portion of the sleeve located in the vicinity of the extrusion die is also provided with cooling means, so that the product exits the extrusion die at a temperature of 50 C.

  According to one possibility, these cooling means may consist of a pipe running through said portion and in which circulates a cooling liquid, for example arranged helically with respect to the axis of the extruder. This coolant can, very simply, consist of water.

  In the abovementioned structure in which the inverted-threaded screw module or modules are placed downstream of at least one fine-pitch module, the sheath comprises at least one axial lock allowing the dough being extruded to be partially discharged upstream, said lock then at least partially overlapping the one or more modules with a reverse pitch and the one or more fine pitch modules placed immediately upstream.

  The usefulness of this repression is to allow a single-screw operation that is similar to the regulation of the extrusion process that could be obtained using a two-screw technology. The consequence is in particular a pressure regulation for extruding and mixing in good conditions the paste obtained by adding the liquid material to the pulverulent material.

  Given the length that can take the extruder, the sheath can also be made of modular sleeves placed end to end and which can be connected by external annular collars.

  At the end of extrusion, the die has a network of holes with a diameter of about 2 mm to obtain cylindrical extrudates. The number of holes is several tens, for example between two and three. cents.

  In other words, the products obtained are cylindrical filaments whose length depends on the frequency given to the cutting device at the exit of the die.

  These filaments must then be spheronized, ie spherical, and the spheronization device of the invention comprises for this purpose a container whose bottom is a perforated plate rotating at variable speed, said container being fed with pressurized air via perforations and the periphery of the turntable, creating a cushion of air on and around the tray.

  Preferably, the turntable is driven by an electric motor controlled by a frequency converter. Finally, the air is injected at a pressure of between 3 and 10 bars, and according to a variable flow rate.

  The extrudates in filamentary form as produced are initially broken down into powder grains. This is due to the rotation of the turntable and the existence of the air cushion. In a second step, the rotation allows a reconstitution of the grains, in the form of more or less round agglomerates. The size of the agglomerates is a function of the speed of rotation, and owes nothing to the size of the orifices of the extrusion die ri along the length of the filaments. The degree of humidity also influences the spheronization, and it is not excluded to modify the hygrometry of the exudates, for example by steam injection.

  The apparatus for producing granules of the invention also comprises a drying device, which comprises at least one chamber animated by a pendulum movement, hermetically closed by a cover blocking the introduction opening of the granules, and supplied with air at a temperature between 90 C and 130 C according to a variable flow rate.

  These drying chambers further include a controlled air extraction orifice, for example connected to a variable speed extractor.

  The assembly makes it possible to round the granules, to dry them gradually and, finally, to depilate them.

  As indicated above, in addition to the apparatus, the invention also relates to a process for producing granules containing at least one concentrated active ingredient, for example a plant that is mixed with one or more substances, in particular adsorbent and / or absorbent, comprising a step of extrusion of the powdered and liquid components in pasty extrudates then transformed into granules, and characterized in that it comprises: - the extrusion of a pulverulent material, said material comprising at least one adsorbent and / or absorbent substance; injecting a liquid concentrated extract of at least one concentrated active ingredient into at least one point of the extrusion step; heating the mixture formed of the pulverulent material and the concentrated extract to a temperature of at least 70 ° C .; the sectioning of the extrudates in the form of filaments; spheronization of said extrudates; and - their drying.

  The injection of the liquid extract is done chronologically after a first phase of extrusion of dry matter, and allows as mentioned to lead to very high concentrations of active ingredient, based essentially on the use of close extracts. soft or firm extracts meeting the definition given in particular by the French pharmacopoeia, since they can have a dry residue of up to 65% w / w.

  Once again, the order of the steps of the process is not insignificant given the viscosity of these extracts, by definition much greater than that of the liquid extracts, and with which it is not possible to carry out the extrusion immediately from a pasty mixture. On the one hand, it would be extremely difficult to obtain with correct homogeneity characteristics, and on the other hand almost impossible to distribute, via a hopper and a system of regulation of the quantity of dough that is reasonably reliable, in the extruder.

  This is the reason why, when one wants to be able to obtain granules with a high concentration of active principle, it is necessary to proceed by first extruding the strictly powdery material, and then injecting the viscous liquid, which allows in passing to benefit from the regulation of the supply of dry matter provided by the screw of the extruder.

  The mixture, once formed in the extruder, is heated to a temperature above 70 C to obtain the aforementioned thermal flash for fixing the active ingredient on the adsorbent and / or absorbent, which is obtained as has been seen by a modification of the pitch of the extrusion shaft on the one hand, and the use of external heating means on the other hand. To be complete, it should be added that this thermal flash is of considerable importance since it effects a structural transformation of the polymers constituting the adsorbent and absorbing substances, as well as the debacterization of the products.

  In addition to the injection of a liquid extract, the method of the invention may comprise at least one additional step of injecting a neutral liquid to correct the concentration of the mixture, for example water, with or without alcohol. The correction of concentration allowed by this injection step possibly inserted into the process can actually facilitate the economy of the latter: it is thus possible to simplify the manufacture of the extract, especially when it is obtained by evaporation, in regulating the evaporator once for the whole in order to produce extracts having a uniform concentration, and then managing downstream the measurement of the concentration that is to be obtained for the granules by means of liquid injection neutral.

  When the extrudates were spheronized, by rotating at variable speed in the presence of an air cushion using the spheronizer described above, they are dried by stirring in a hot air stream at a temperature above 90 C. already indicated, the injection pressure is in the process between 3 and 10 bar.

  According to possibilities known per se, the adsorbent and / or absorbent substances may in particular be chosen from cellulose, lactose and / or maltodextrose, or any other equivalent product, that is to say having adsorption properties and equivalent absorption.

  In the invention, the pulverulent material may itself comprise dry concentrated extract of at least one active ingredient, for example a plant. The addition of active ingredient, in powder form, in the first step of the process allows a further adjustment of the concentration, if necessary. This pulverulent material may also contain in particular one or more adjuvants chosen from sweetening, binding, disintegrating or flavoring agents, as the case may be.

  It may finally contain sugars in the form of fructose, sorbitol, xylitol or the like.

  Similarly, the injected liquid may in particular comprise at least one adjuvant chosen from diluents, wetting agents, flavoring agents and / or sweeteners.

  According to the method, which corresponds to the granule manufacturing apparatus explained above, the extrusion pressure of the mixture is increased after the first injection phase, the pressure increase being accompanied by a rise in temperature . This participates in obtaining the threshold temperature of 70 C for obtaining the thermal flash for fixing the active ingredient (s) on the adsorbent and / or absorbent substrate (s). The temperature can be further increased by using additional heating means of the heating resistor type.

  Then, the extrusion temperature is deliberately lowered, in the vicinity of the die, by cooling means of the driving type carrying a cooling liquid, for example in the form of a water circuit.

  The process of the invention is preferably based on the injection of at least one liquid extract which can for example be obtained by alcohol evaporation under vacuum.

  The invention will now be described in more detail, with reference in part to the appended FIG. 1, which schematically shows an apparatus for producing granules according to the invention, and on the other hand to examples of the manufacture of granules. based on several distinct active ingredients.

  With reference to FIG. 1, the modular extruder consists of an extrusion screw composed of different modules, the threads of which have not different, in the portions (1, 2), and an inverted thread, in the portion (3). The extrusion shaft thus formed is surrounded by a sheath (4) at the upstream end of which is a motor assembly (5) consisting of an electric motor associated where appropriate with a gearbox. An extrusion die (6) is disposed at the downstream end of the extrusion shaft. This die (6) is in fact made up of a multitude of small orifices (more than two hundred), preferably of identical diameters, making it possible to produce extrudates in the form of filaments of small diameter (of the order of 2 mm) and of limited length, resulting from the frequency conferred on the cutting device (7) disposed downstream of the die (6). The filamentary extrudates thus produced are expelled via the opening (8) to the spheronizer (not shown).

  The extruder thus constituted is fed via the hopper (9) and a device for regulating the flow rate of the powder entering the screw (10), controlled by a frequency converter.

  The powder delivered to the first portion (1) of the extrusion shaft is conveyed to a second portion (2), placed at a liquid supply nozzle (11), said liquid preferably being an extract close to soft or firm extracts in at least one active concentrate, for example obtained from plant (s). A second injection nozzle (12) may be implanted near the downstream end of the second portion (2) for the injection of a neutral liquid of the water and / or alcohol type. According to one possibility, the injection diameter is of the order of 1 mm, and the two nozzles are spaced about 20 cm.

  This second portion (2) has a thinner pitch thread than the portion (1), which increases the pressure and therefore the temperature of the mixture consisting of the pulverulent material and the liquid extract.

  Additional heating means (13) can further increase, if necessary, said temperature so that it exceeds 70 C, and that the flash attachment can be obtained.

  The last portion (3) of the extrusion shaft comprises an inverted-pitch threading, making it possible to regulate the extrusion process, in combination with axially-oriented locks (not shown), so as to obtain a substantially identical to that of a twin-screw extruder. In this end portion of the extrusion shaft, cooling means (14) are provided to reduce the pulp during extrusion to a lower temperature, so that extrudates are obtained at the outlet of the die. which are at a temperature between 50 C and 60 C.

  Said extrudates obtained at the outlet (8), of filamentary shape, are then spheronized and dried in order to obtain the finished product, namely the granules 2882663 9 concentrated in active extract. The process allows the extrusion of a large quantity of product: from 70 to 100 kg per hour for an apparatus of reasonable dimensions.

  Various examples, presented below, will provide a better understanding of the apparatus and method of the invention.

EXAMPLE 1

  Preparation of microgranules of HARPAGOPHYTUM in capsule of which one capsule of 380 mg contains 7 mg of harpagoside.

  A soft extract of harpagophytum is prepared according to the technique described above with a dry residue of 61.14% with a concentration of 21.73 gr / kg of harpagoside, a density of 1.232 and using as binder microcrystalline cellulose. To make 100 kg of microgranules, it is necessary to use 48.17 kg of cellulose microaistaline, to inject with a dosing pump 72.255 liters of soft extract and to inject in a second point 3.45 liters of water. Thus, 380 mg of micro granule will contain 7 mg of harpagoside.

  Technical data: Rotational speed of the extruder shaft: 500 rp m; Injection per minute of 652 g microcrystalline cellulose and 978 cc liquid including 95.44% concentrated extract and 4.56% water.

  Granules which can contain up to 51.83% of hyalcoholic components are obtained from harp agop hytum.

EXAMPLE 2

  Preparation of microgranules of BROCOLI of which one capsule of 385 mg contains 0.3 mg of sulforaphane.

  Extrusion of 70 kg of Broccoli plant powder mixed with 30 kg of cellulose, injection into the extruder of 580 g of the broccoli / binder mixture per minute, injection into the water extruder for texturing and obtaining the granules.

  Technical data: Rotational speed of the extruder shaft: 500 rp m; injection per minute of 580 gr of Broccoli plant powder with 30% microcrystalline cellulose added.

  100 kg of microgranules of broccoli powder are obtained, of which 385 mg contain 0.3 mg of sulforaphane.

  The granules obtained can contain up to 700% of plant powder. EXAMPLE 3 Preparation of micro granules of GINGKO BILOBA in capsule of which one 380 mg capsule contains 10 mg of total ginkgoflavonoids.

  A mixture of 89.3 kg of cellulose with 10.7 kg of dry ginkgo grading 24.6% of total gingkoflavonoids, ie 100 kg of powder entering the extruder.

  Technical data: Speed of the extruder shaft 530: rp m; Injection per minute of 680 gr of the powder mixture and injection into the screw of the extruder of 146.3 liters of alcohol at 10.

  100 kg of gingko biloba microgranules are obtained, 380 mg of which contain 10 mg of total gingkoflavonoids.

Claims (3)

1. Apparatus for producing granules containing at least one concentrated active ingredient, for example plant mixed with one or more components including adsorbent and / or absorbent, comprising a feed hopper (9), a screw extruder surrounded by a sheath (4), a die (6) disposed at the outlet of the extruder, a cutting device (7) extrudates produced by the die (6), a spheronization device extrudates, and a device for drying granules and constituted, characterized in that: - the extruder is modular and single-screw; the extrusion screw consists of threaded modules (1, 2, 3) with variable pitch placed end to end, of which at least one module (3) comprises an inverted thread; the extruder is provided, downstream of the hopper (9), with at least one liquid injection nozzle (11, 12) associated with a device for regulating the quantity of liquid injected. 2. Apparatus for producing granules according to the preceding claim, characterized in that the extruder is provided with two nozzles (11, 12) of liquid injection, arranged at two axially distinct points of the extruder. 3. Apparatus for manufacturing granules according to one of the preceding claims, characterized in that each nozzle (11, 12) of liquid injection is connected to a reservoir of said liquid via a pump whose flow and pressure are adjustable. 4. Apparatus for producing granules according to any one of the preceding claims, characterized in that the feed hopper (9), filled only with pulverulent material, is connected to the extruder via a control device (10) of the amount of pulverulent material delivered to the extruder. 5. Apparatus for producing granules according to any one of the preceding claims, characterized in that the pitch of the thread is reduced in the vicinity of the first nozzle (11). 6. Apparatus for producing granules according to any one of the preceding claims, characterized in that the inverted-threaded module (3) is disposed downstream of the last nozzle (12) of injection. 7. Apparatus for producing granules according to any one of the preceding claims, characterized in that at least a portion of the sleeve (4) surrounding the extrusion screw comprises heating means (13). 8. Apparatus for producing granules according to the preceding claim, characterized in that said heating means (13) consist of resistances traversed by an electric current and embedded in the sleeve (4) 9. Apparatus for producing granules according to the any one of the preceding claims, characterized in that a portion of the sleeve (4) in the vicinity of the extrusion die (6) is provided with cooling means (14). 10. Apparatus for producing granules according to the preceding claim, characterized in that said cooling means (14) consist of a pipe running through said portion and in which circulates a cooling liquid. 11. Apparatus for producing granules according to the preceding claim, characterized in that the pipe is arranged helically with respect to the axis of the extruder. 2. Apparatus for producing granules according to any one of the preceding claims, characterized in that the sheath (4) comprises at least one axial lock allowing the dough being extruded to be partially displaced upstream. said lock overlapping at least partially the at least one reverse-pitch module (3) and the at least one threaded module (2) which is placed upstream. 13. Apparatus for producing granules according to any one of the preceding claims, characterized in that the sheath (4) is composed of modular sleeves placed end to end, which can be connected by external annular rings. 4. Apparatus for producing granules according to any one of the preceding claims, characterized in that the die (6) comprises a network of holes with a diameter of about 2 mm to obtain cylindrical extrudates .   Granule manufacturing apparatus according to any one of the preceding claims, characterized in that the spheronization system comprises a container whose bottom is a perforated plate rotating at variable speed, said container being supplied with dry air and pressurized via perforations and the periphery of the turntable creating a cushion of air on and around the tray.   16. Apparatus for producing granules according to the preceding claim, characterized in that the turntable is driven by an electric motor controlled by a frequency converter.   17. Apparatus for producing granules according to one of claims 15 and 16, characterized in that the air is injected at a pressure between 3 and 10 bar, variable flow.   18. Apparatus for producing granules according to any one of the preceding claims, characterized in that the drying device comprises at least one chamber animated by a pendulum movement, hermetically closed by a cover blocking the granules introduction opening , and supplied with air at a temperature of between 90 ° C. and 130 ° C. in a variable flow rate.   19. Apparatus for producing granules according to the preceding claim, characterized in that the drying chamber is provided with an orifice for the controlled extraction of air.   20. A process for the production of granules containing at least one concentrated active ingredient, for example a plant that is mixed with one or more substances, in particular adsorbent and / or absorbent, comprising a step of extruding the components in powdery and liquid form into pasty extrudates transformed into granules, characterized in that it comprises: the extrusion of a powdery material, said material comprising at least one adsorbent and / or absorbent substance; injecting a liquid concentrated extract of at least one concentrated active ingredient into at least one point of the extrusion step; heating the mixture formed of the pulverulent material and the concentrated extract to a temperature of at least 70 ° C .; the sectioning of the extrudates in the form of filaments; spheronization of extrudates; and - their drying.   21. A method of manufacturing granules according to the preceding claim, characterized in that the concentrated extract has a dry residue of up to 65% w / w.   22. A method of manufacturing granules according to the preceding claim, characterized in that it comprises a step of injecting a neutral liquid to correct the concentration of the mixture obtained after injection of the concentrated extract into the pulverulent material. extrusion course.   23. A method of manufacturing granules according to the preceding claim, characterized in that the neutral liquid consists of water, with or without alcohol.   4. Process for the production of granules according to any one of claims 20 to 23, characterized in that the spheronization is carried out by rotating the extrudates in a container at a variable speed in the presence of a cushion of air.   25. A method of manufacturing granules according to the preceding claim, characterized in that the air cushion is obtained by injecting air into the bottom of the container at a pressure between 3 and 10 bar.   6. Process for producing granules according to any one of claims 20 to 25, characterized in that the granules obtained by spheronization are dried by stirring in a flow of hot air at a temperature above 90 C.   7. Process for the production of granules according to any one of claims 20 to 26, characterized in that the adsorbent and / or absorbent substances are chosen from cellulose, lactose or maltodextrin.   28.Process of manufacturing granules according to any one of claims 20 to 27, characterized in that the pulverulent material comprises dry concentrated extract of at least one active ingredient, for example plant.   9. Process for producing granules according to claim 20, characterized in that the adsorbent and / or absorbent substrates contain sugars, chosen from fructose, sorbitol or xylitol.   Process for the production of granules according to one of Claims 20 to 29, characterized in that the pulverulent material contains one or more adjuvants chosen from sweetening, bindering, disintegrating or flavoring agents.   The method of manufacturing granules according to any one of claims 20 to 30, characterized in that the injected liquid comprises at least one adjuvant selected from among diluents, wetting agents, flavoring agents and sweetening agents.   32.Process for manufacturing granules according to any one of claims 20 to 31, characterized in that the extrusion pressure of the mixture is increased near the first injection point, the pressure increase being accompanied by a rise in temperature.   33. A method of manufacturing granules according to the preceding claim, characterized in that the extrusion temperature is increased after the first injection point by additional heating means of the heating resistor type.   34.The method of manufacturing granules according to any one of claims 20 to 33, characterized in that the extrusion temperature is lowered in the vicinity of the die by cooling means of the driving type carrying a cooling liquid.   35.Process for the production of granules according to any one of claims 20 to 34, characterized in that the liquid extract is obtained by alcohol evaporation under vacuum.