System and method for coating powdered raw material onto carrier particles rotating in a turbine

Abstract

The invention relates to a system (10) for coating powdered raw material, the system comprising: a turbine (12) for rotating a mass of carrier particles (20) in a direction of rotation; a dosing device (14) for introducing at least one powdered raw material (26) into the turbine (12), wherein the dosing device (14) comprises a feed screw (22) having an end (28) configured to be arranged in the mass of carrier particles (20); a spray nozzle (16) for spraying a liquid (32) into the turbine (12), wherein the spray nozzle (16) has an outlet (30) configured to be arranged in the mass of carrier particles (20), and wherein the outlet (30) of the spray nozzle (16) is positioned downstream of the end (28) of the feed screw (22) in the direction of rotation of the mass of carrier particles (20), such that the powdered raw material (26) is mixed by the nozzle delivering the sprayed liquid (32).

Description

Description Title: System and method for powdering powdered raw material onto carrier particles rotating in a turbine Technical field

[0001] The present disclosure relates to the field of powdering assembly of powdered raw material onto carrier particles rotating in a turbine. Prior art

[0002] Systems for carrying out the operation of mounting by powdering powdered raw material onto rotating support particles typically comprise an open turbine adapted to contain a mass of support particles and to drive it in rotation. A powdered raw material, which may be an active ingredient or an excipient, as well as a liquid or binder, is introduced into the mass of support particles, until microgranules of active ingredient are obtained, which can then be further coated.

[0003] Typically, an operator is responsible for introducing the liquid using a beaker-type container, adding the powdered raw material using a shovel or similar tool, and manually ensuring the correct distribution of the powdered raw material in the mass of support particles by covering and stirring.

[0004] In order to facilitate the role of the operator, it has been proposed in particular to use a spraying system to spray the liquid into the turbine, to operate a dosing device, otherwise known as a powderer, to supply the powdered raw material and to provide a stirring comb and / or a covering shovel to replace manual stirring and covering.

[0005] Thanks to the introduction of these tools, the operator's role is to manually feed the doser, to regularly adjust, according to the increase in the rotating mass in the turbine, and possibly the change in its inclination, the position of the spraying system, the covering shovel and / or the mixing comb.

[0006] However, it has been found that, as the rotating mass increases throughout the process, several tool adjustments are necessary to maintain a positioning suitable for the smooth running of the operation. The number of tools used complicates access to the area around the turbine opening to carry out their regular repositioning.

[0007] In addition, the correct positioning of the tools requires a good knowledge of the assembly operation, which is difficult for an inexperienced operator to understand. Precise positioning of the tools is necessary to achieve good granulometric homogeneity of the microgranules. Summary

[0008] A system for mounting by powdering powdered raw material onto support particles is proposed, comprising: - a turbine configured to rotate a mass of support particles in a direction of rotation; - a doser configured to introduce at least one powdered raw material into the turbine, the doser comprising a feed screw having one end configured to be arranged inside the mass of support particles; - a spray nozzle configured to spray a liquid into the turbine, the spray nozzle having an outlet configured to be arranged inside the mass of support particles, the outlet of the spray nozzle is positioned downstream of the end of the feed screw in the direction of rotation of the mass of support particles, so that the powdery raw material coming from the metering device is stirred by the spray nozzle supplying the liquid.

[0009] Thus, advantageously, the feed screw allows the powdery raw material to be delivered by producing a first mixing of the moving mass, which promotes an immediate distribution of the powdery raw material, driven by the speed of movement of the support particles, and significantly limits the dispersion of the powdery material in the air. The spray nozzle then allows a second mixing, further promoting the good distribution of the powdery raw material in the mass of support particles while avoiding sticking of the support particles or the powdery raw material on the walls of the turbine. The appearance of the microgranules obtained following the use of this system is satisfactory, and a good distribution of the powdery raw material is obtained on the support particles.The system allows to obtain a granulometric homogeneity of the microgranules in a regular and repeatable manner, independently of the experience and technicality of the operator.

[0010] Optionally, the spray nozzle and the feed screw can extend at a negative angle from the outside of the turbine to the inside of the turbine. Thus, the powdered raw material and the liquid are carried directly by the movement of the support particles. The feed screw can deliver the powdered raw material into the mass of support particles without generating stress, avoiding a packing phenomenon of the powdered raw material at the end of the feed screw. The spray nozzle can also spray the liquid while minimizing its stress with respect to the rotating mass in the turbine, and in the arrival line of the powdered raw material. The distribution of the powdered raw material in the mass of support particles is improved.

[0011] Optionally, a distance between the outlet of the spray nozzle and the end of the feed screw can be between approximately 100 and 700 mm. The spraying is carried out in continuity with the line of arrival of the powdered raw material in the mass of support particles, further improving the mixing of the powdered raw material. The distribution of the powdered raw material in the mass of support particles is further improved.

[0012] Optionally, the spray nozzle and the metering device can each be mounted on adjustment means, the adjustment means being arranged outside the turbine, the means adjustments being adapted to modify the inclination and height of each of the spray nozzle and the feed screw. An operator can thus make the positioning adjustments of the spray nozzle and the metering device so that the spray nozzle is in the correct alignment with the feed of powdered raw material, possibly with an inclination minimizing its stress with respect to the rotating mass in the turbine. The operator can make adjustments from outside the turbine, ensuring a safe operation and requiring less physical effort and exposure to the product. The adjustments allow the system to be adapted to the mass of carrier particles in the turbine and make the system more flexible and adaptable.

[0013] Optionally, the spray nozzle may comprise: a first orifice configured to spray liquid, a second annular orifice, coaxial with the first orifice, configured to spray compressed air. This results in atomization of the sprayed liquid at liquid flow rates that may be less than 0.5 g / s. Atomization means the transformation of a liquid into fine droplets using a gas emitted under pressure, such as compressed air. The mounting system may be adapted to different flow rate ranges, making it possible to produce a large number of different microgranules. This improves the flexibility and adaptability of the system.

[0014] Optionally, the spray nozzle may include a third annular orifice, coaxial with the first and second orifices, configured to spray compressed air. The third orifice forms an air “tube” around the liquid jet, which protects it from moving support particles. When the outlet of the spray nozzle is immersed in the mass, this “tube” forms a dome which allows the atomization of the liquid within the support particles, without double particles or an overwetting / agglomeration phenomenon appearing. This ensures good atomization and good distribution of the sprayed liquid.

[0015] Optionally, the mounting system may include a probe mounted in the turbine and configured to measure the temperature of the rotating mass of support particles. It is then possible to monitor the regularity of liquid evaporation by measuring the temperature of the rotating mass. This makes the mounting easier to monitor, and operator intervention is reduced.

[0016] According to another aspect, there is provided a method of mounting by powdering powdered raw material onto support particles comprising: - introduce a mass of support particles into a turbine; - drive the turbine in rotation to move the mass of support particles in the turbine in a direction of rotation; - supplying at least one powdered raw material into the mass of support particles by means of a supply screw comprising one end immersed in the mass of support particles; - together with the supply of powdered raw material, spray a liquid into the mass of support particles by means of a spray nozzle comprising an outlet immersed in the mass of support particles, downstream of the end of the feed screw following the direction of rotation of the mass of support particles.

[0017] Such a process allows for an initial mixing of the moving mass by the addition of the powdered raw material, which promotes an immediate distribution of the powdered raw material, driven by the speed of movement of the support particles, and significantly limits the dispersion of the powdered material in the air. The spray nozzle then allows a second mixing, further promoting the good distribution of the powdered raw material in the mass of support particles while avoiding sticking of the support particles or the powdered material on the walls of the turbine. The appearance of the microgranules obtained following the process is satisfactory, and a content uniformity test shows a good distribution of the powdered raw material on the support particles. Therefore, the process is regular / repeatable and homogeneous, regardless of the experience and technicality of the operator.

[0018] Optionally, the supply of powdered raw material and the spraying can be carried out continuously. The process has no rest time allowing the operator to successively carry out stirring, covering and / or supply of powdered raw material. In addition, the sprayed liquid is evaporated during the implementation of the process, and it is not necessary to interrupt it to allow the evaporation of the liquid. The total process time is thus reduced and the yield improved.

[0019] Optionally, the liquid spraying may include atomizing the liquid and applying an air tube around the liquid from the spray nozzle. The use of atomizing and the air tube produces a spray in the carrier particles that does not generate double particles or overwetting / agglomeration phenomena. Brief description of the drawings

[0020] Other features, details and advantages will become apparent upon reading the detailed description below, and upon analyzing the attached drawings, in which: Fig. 1

[0021] [Fig. 1] schematically illustrates a front view of a mounting system according to one embodiment. Fig. 2

[0022] [Fig. 2] schematically illustrates a first detail of figure 1. Fig. 3

[0023] [Fig. 3] schematically illustrates a second detail of Figure 1. Fig. 4

[0024] [Fig. 4] schematically illustrates a side view of a spray nozzle that may be implemented in the mounting system of Fig. 1 according to one embodiment. Fig. 5

[0025] [Fig. 5] schematically illustrates a front view of the spray nozzle of Figure 4. Fig. 6

[0026] [Fig. 6] illustrates a flowchart of an assembly process according to one embodiment. Fig. 7

[0027] [Fig. 7] is a photograph of an example of support particles according to one embodiment. Fig. 8

[0028] [Fig. 8] is a photograph of an example of coated microgranules obtained using the system of Figure 1 and / or the assembly method of Figure 6 according to one embodiment. Description of the embodiments

[0029] Figure 1 schematically illustrates a mounting system 10 by dusting powdered raw material onto support particles, to form microgranules of active ingredient, which can then be further coated. Any type of powdered raw material can be mounted onto support particles with the system according to the invention, both excipients and active ingredients. For example, as active ingredients, mention may be made of Diltiazem, Vitamin C, Ketoprofen, Morphine, Secnidazole, Theophylline.

[0030] As illustrated, the mounting system 10 includes a turbine 12, a metering device 14 and a spray nozzle 16.

[0031] The turbine 12 comprises a cylindrical casing delimited by a side wall 18 and mounted on supports (not shown). The cylindrical casing forms a container adapted to receive a mass of support particles 20. The turbine 12 may have a capacity to receive a mass of support particles 20 of between 20 kg and 350 kg, preferably between 40 kg and 300 kg. Therefore, the turbine 12 is suitable for mounting microgranules in batches of variable volume.

[0032] The turbine 12 is mounted on the supports to rotate about an axis of rotation X. In the illustrated example, the rotation is clockwise, but the rotation could also be counterclockwise. The rotation of the turbine 12 about its axis of rotation X makes it possible to rotate the mass of support particles 20 in a direction of rotation. The mass of support particles 20 moves in the turbine 12 in the direction of rotation in a bean-shaped motion. The support particles are carried along the side wall 18 of the turbine 12 before falling towards a bottom of the turbine 12 and mixing.

[0033] The rotation axis X of the turbine 12 is inclined relative to a horizontal axis. The angle of inclination of the turbine 12 is between 0° and 45°, preferably between 10° and 35°. The inclination of the turbine 12 contributes to the bean-shaped movement of the mass of support particles 20, preventing the support particles from stagnating in the bottom of the turbine 12.

[0034] As more visible in Figure 2, the dosing device 14 comprises a feed screw 22 and a reservoir 24.

[0035] The tank 24 makes it possible to store a volume of powdered raw material 26. The powdered raw material 26 may be one or more active ingredients, one or more excipients or a mixture of one or more active ingredients and one or more excipients. The tank 24 may have a storage capacity of a volume of powdered raw material 26 of between 5 and 100 kg, preferably between 15 and 50 kg. It is thus possible to produce a large volume of microgranules of active ingredient, which can still be coated subsequently, without an operator needing to feed the tank 24 too frequently or permanently.

[0036] The feed screw 22 extends along a longitudinal axis from the reservoir 24 to an end 28 provided inside the turbine 12. The feed screw 22 makes it possible to convey the powdery raw material 26 from the reservoir 24 to the inside of the turbine 12. The powdery raw material 26 is distributed by being expelled from the end 28 of the feed screw 22. Here, the end 28 of the feed screw 22 is configured to be immersed inside the mass of support particles 20. The feed screw 22 thus produces a first mixing of the moving mass 20, which promotes an immediate distribution of the powdery raw material 26, driven by the speed of movement of the support particles, and limits the dispersion of the powdery material 26 in the air.

[0037] When the turbine 12 is viewed from the front, the end 28 of the feed screw 22 is located in an upper portion of the turbine 12, such that the end 28 of the feed screw 22 is immersed in the upper third of the moving mass of support particles 20. When the direction of rotation is clockwise, the end 28 of the feed screw 22 is located in a left-hand portion of the turbine 12 (see FIG. 1). Conversely, when the direction of rotation is counterclockwise, the end 28 of the feed screw 22 is located in a right-hand portion of the turbine 12 (not shown). This positioning of the end 28 of the feed screw 22 promotes good mixing of the powdered raw material 26 in the mass of support particles 20.

[0038] The reservoir 24 is positioned vertically above the end 28 of the feed screw 22. The feed screw 22 follows a negative inclination from the reservoir 24 outside the turbine 12 to the end 28 inside the turbine 12. In practice, the feed screw 22 defines an angle of inclination of between 2° and 45°, preferably between 10° and 35° with a horizontal axis. Thus, the powdery raw material 26 is driven directly by the movement of the support particles in the turbine 12. The feed screw 22 can deliver the powdery raw material 26 into the mass of support particles 20 without generating stresses, avoiding a phenomenon of compaction of the powdery raw material at the end 28 of the feed screw 22.

[0039] The length of the feed screw 22 is greater than 500 mm. The end 28 of the feed screw 22 can then be immersed in a mass of 40 kg as well as in a mass of 300 kg. The feed screw 22 is suitable for mounting many different microgranules. Furthermore, the diameter of the feed screw 22 can be between 20 mm and 50 mm, preferably between 30 mm and 40 mm. The feed screw 22 can then be adapted to convey a large number of different powdery raw materials 26, without any settling of the powdery raw material at the end 28 of the feed screw 22 occurring.

[0040] Figures 3 to 5 illustrate the spray nozzle 16 in more detail.

[0041] The spray nozzle 16 is supported from outside the turbine 12 by a support arm or any other means to an outlet 30 inside the turbine 12, so as to spray a liquid 32 inside the mass of support particles 20. The liquid 32, or solution, or suspension, can be any liquid promoting good adhesion of the powdery raw material 26 to the support particles, or the coating of the support particles or microgranules of active ingredient. Any type of solution or suspension can be implemented with the system according to the invention. For example, shellac in alcoholic solution can be mentioned. The spraying of the liquid 32 into the mass of support particles 20 provides a second mixing further promoting good distribution of the powdery raw material 26 in the mass of support particles 20.Spraying in the mass 20 also makes it possible to avoid sticking of the support particles or the powdered raw material on the side wall 18 of the turbine 12. It is not necessary to provide additional mixing downstream of the spraying.

[0042] The outlet 30 of the spray nozzle 16 is downstream of the end 28 of the feed screw 22 in the direction of rotation of the support particles in the turbine 12. Therefore, seen from the front, the spray nozzle 16 is vertically below the feed screw 22. When the direction of rotation is clockwise, the outlet 30 of the spray nozzle 16 is to the right relative to the end 28 of the feed screw 22. Conversely, when the direction is counterclockwise, the outlet 30 of the spray nozzle 16 is to the left relative to the feed screw 22. Furthermore, the outlet 30 of the spray nozzle 16 is substantially in the same transverse plane of the turbine 12 as the end 28 of the feed screw 12. Thus, the outlet 30 of the spray nozzle 16 is in the arrival line of the raw material. powder 26 coming from the end 28 of the feed screw 22.The spraying contributes to the good mixing of the powdered raw material 26 in the mass of support particles 20.

[0043] Here, the distance D between the end 28 of the feed screw 22 and the outlet 30 of the spray nozzle 16 is between approximately 100 mm and 700 mm, preferably between 100 mm and 400 mm. The outlet 30 of the spray nozzle 16 is positioned to be close to the stirring movement generated by the end 28 of the feed screw 22. Therefore, the liquid 32 can be sprayed close to the arrival line of the powdery material 26, improving its stirring and the adhesion of the powdery raw material 26 to the support particles.

[0044] Furthermore, the spray nozzle 16 extends towards the inside of the turbine 12 at a negative inclination. One end of the nozzle 16 in the vicinity of the inlet of the turbine 12 is vertically above the outlet 28 of the nozzle 16. Furthermore, the spray nozzle 16 extends substantially at an angle of inclination α of between 2° and 60°, preferably between 10° and 45° relative to a vertical axis. Here again, the liquid 32 is sprayed while limiting its stress with respect to the mass 20 rotating in the turbine 12.

[0045] As more visible in Figure 4, the spray nozzle 16 has a length L greater than 200 mm. Thus, the spray nozzle 16 has a length L sufficient for the outlet 30 of the spray nozzle 16 to be immersed in the mass of support particles 20, even when this the latter is low (for example less than 40 kg). The spray nozzle 16 also has a diameter greater than 20 mm. The robustness and dimensions of the spray nozzle 16 are sufficient to withstand the stresses induced by its immersion in the moving mass of support particles 20, even when the mass reaches 300 kg or 350 kg.

[0046] As more visible in Figure 5, the spray nozzle 16 is a tri-fluid nozzle. The outlet 30 of the nozzle 16 comprises a first, central orifice 34, connected to a liquid supply 34a for spraying the liquid 32. The outlet 30 of the spray nozzle 16 also comprises a second, annular orifice 36, coaxial with the first orifice 34, connected to a compressed air supply 36a. The shear forces exerted by the air leaving the second orifice 36 ensure the atomization of the liquid 32 leaving the first orifice 34 into fine droplets.

[0047] The first orifice 34 has for example a diameter between 0.5 mm and 3 mm, preferably between 1.5 mm and 2.5 mm. The diameter of the first orifice 34 influences the maximum flow rate of the liquid to be sprayed and the size of the droplets atomized using the second orifice 36. An increase in the diameter of the first orifice 34 results in an increase in the maximum flow rate of sprayable liquid. The diameter of the first orifice 34 can be chosen to meet different ranges of flow rates and liquids to be sprayed. The pressure and / or air flow rate of the orifice 36 will be adjusted to ensure suitable atomization. For example, an increase in the pressure and / or air flow rate of the orifice 36 results in a decrease in the size of the atomized droplets.

[0048] Here, the spray nozzle 16 comprises a third annular orifice 38, coaxial with the first and second orifices 34, 36. The third orifice 38 is connected to a second compressed air outlet 38a. The third orifice 38 is adapted to form an air “tube” around the liquid jet 32 ​​to protect it from the carrier particles. The air from the third orifice 38 slightly moves the carrier particles away from the outlet 30 of the nozzle 16 in order to prevent them from agglomerating and to keep them at a sufficient distance to allow the atomization of the liquid 32.

[0049] The spray nozzle 16 and the metering device 14 may be mounted from outside the turbine 12 on adjustment means (not shown). For example, the spray nozzle 16 may be supported by an arm connected to a bracket. Any other type of adjustment means accessible to those skilled in the art may be provided. The adjustment means make it possible to adjust the spray nozzle 16 and the feed screw 22 respectively to ensure good alignment of the outlet 30 of the nozzle 16 and the end 28 of the feed screw 22 in a transverse plane of the turbine 12. The adjustment means also make it possible to position the spray nozzle 16 and the feed screw 22 to ensure a supply of liquid 30 and powdered raw material 16 in a front third of the mass of support particles 20. The operator can make the adjustments from outside the turbine 12, without special knowledge.According to an exemplary embodiment, the adjustment means may comprise visual indicators making it possible to further facilitate the correct positioning of the nozzle 16 and the feed screw 22.

[0050] In some cases, a probe (not shown) may be installed in the turbine 12. The probe is configured to measure the temperature of the rotating mass of support particles 20. Thus, The probe can monitor the regularity of liquid evaporation. The operator's role is further reduced.

[0051] A method for mounting 100 powdered raw material on support particles is described below. The method can, for example, be implemented by the system described above.

[0052] According to a first step 110, the mass of support particle 20 is introduced into the turbine 12. The mass of support particle 20 introduced into the turbine 12 may for example be between 20 kg and 350 kg. The support particles are, in step 110, in the form of microgranules 40 of small diameter devoid of powdery raw material 26 (see figure 7). The support particles may have a diameter for example between 200 pm and 1500 pm, preferably between 400 pm and 900 pm.

[0053] According to a second step 120, the mass of support particles 20 is driven by the rotation of the turbine 12 in a direction of rotation (clockwise or counterclockwise). The rotation speed of the turbine 12 is for example between 15 and 30 revolutions / minute, preferably between 20 and 25 revolutions / minute. The rotation speed may be constant or may be modulated during the process depending on the change in the size of the support particles and / or the increase in the rotating mass in the turbine. The support particles are entrained along the side wall 18 of the turbine 12 before falling towards a bottom of the turbine 12 and mixing.

[0054] According to a third step 130, the feed screw 22 is actuated to feed the powdery raw material 26 into the mass of support particles 20. The powdery raw material 26 is introduced into the mass of support particles 20 to induce a first mixing of the mass of support particles 20 and thus promote the mixing of the powdery raw material 26. The flow rate of powdery raw material 26 may for example be between 1 kg / h and 50 kg / h, preferably between 10 kg / h and 40 kg / h. The flow rate may be adapted according to the requirements for the production of different microgranule formulations.

[0055] According to a fourth step 140, carried out jointly with the third step 130, the spray nozzle 16 is actuated to spray liquid 32 into the mass of support particles 20. The positioning of the nozzle, by which the liquid 32 is sprayed into the mass 20, induces a second mixing of the mass of support particles 20, further promoting the dispersion of the powdery raw material 26 in the mass 20. The liquid 32 can be sprayed at a flow rate of between 0.1 g / s and 6 g / s, preferably between 0.5 g / s and 3 g / s, depending on the requirements for producing different microgranule formulations.

[0056] Here, the spraying comprises a sub-step 141 of atomizing the liquid 32. Compressed air is sprayed with the jet of liquid, in particular through the second orifice 36 described above. The compressed air may be at a pressure of less than 1 bar so as to produce atomization that does not generate agglomerations.

[0057] The spraying also comprises, here, a sub-step 142 of applying a “tube” of compressed air around the liquid 32. The “air tube” can for example be generated by the third orifice 38 as described above. The compressed air can be at a pressure of less than 1 bar, so to slightly push the support particles away from the outlet 30 of the spray nozzle 16 and allow the atomization of the liquid 32.

[0058] The above method 100 can be carried out continuously until the powdered raw material 26 is used up. The spraying and the supply of powdered raw material are carried out without interruptions. It is not necessary to provide rest periods for an operator to act on the mass of support particles 20, nor to allow the liquid 32 to evaporate. The efficiency of the method 100 is thereby improved.

[0059] Following the process 100, the mass in the turbine 12 has for example increased by a factor of between 1.1 and 17.5, preferably between 5 and 15. The support particles become microgranules coated with powdery raw material 26. The coated microgranules 42 obtained are for example visible in Figure 8, in which the powdery raw material 26 has been mounted on the support particles 40 visible in Figure 7 taken at the same magnification as Figure 8. Good granulometric homogeneity of the coated microgranules 42 is observed.

[0060] The method 100 may also include a preliminary step of adjusting the positioning of the spray nozzle 16 and the feed screw 22, to ensure the proper progress of the method 100 (alignment and orientation of the nozzle and the screw as described above). Occasionally, the positioning adjustment may be carried out during the method 100, in particular when the mass in the turbine 12 has increased considerably. However, these adjustments are less, not requiring significant physical effort or special knowledge.

[0061] It is noted that several powdered raw materials 26 can be introduced successively, or that a mixture of powdered raw materials 26 can be introduced simultaneously into the turbine 12. Preparation examples

[0062] Example 1: Preparation of Theophylline microgranules.

[0063] Procedure for mounting Theophylline on support particles (here neutral particles of size 400-600 pm composed of sucrose and corn starch) using a 40% alcoholic solution of Bleached Waxless Shellac.

[0064] Setting : The supply of powdered raw material 26 and the spraying are carried out continuously. The spray nozzle 16 is supplied with liquid using a low-pressure tank (container containing the liquid to be sprayed and maintained under a pressure generally lower than 4 bars by the use of a gas such as compressed air to allow regular thrust liquid in the pipe bringing it to the spray nozzle 16). The pressure of this tank is otherwise called spray pressure. The parameters used are as follows:

[0065] ACCURATE type 14 screw powderer. Spray pressure: 1.6 bar. Atomization pressure: 0.4 bar. Liquid flow rate: 1.4 g / s. Powdered raw material feed rate: 4.5 g / s (powder setting: 900). Turbine speed: approx. 20 rpm.

[0066] Initially, spraying is carried out for 4 minutes without adding powdered raw material (Theophylline); the addition is then carried out continuously until the quantity of Theophylline is used up.

[0067] The temperature of mass 20 was monitored in order to control the evaporation of liquid 32. After 1 hour of spraying, we added a dryer blowing air at 25 °C into turbine 12. This allowed the temperature of mass 20 to be stabilized and thus to continue controlling evaporation. The dryer was then positioned so as to blow outside the side wall 18 of turbine 12, leading to a similar result.

[0068] Results : The appearance of the microgranules obtained is satisfactory and the test of uniformity of active raw material content shows a good distribution of the powdered raw material 26. Theoretical content (calculated): 426.7 mg / g Measured content (average of individual values): 438.6 mg / g Individual content values: 437.3 / 440.3 / 438.2 / 435.7 / 436.0 / 443.9 or a CV of 0.7%.

[0069] Example 2: Preparation of Vitamin C microgranules

[0070] Preparation of support particles:

[0071] Conventionally, in turbine 12, support particles are prepared (here neutral particles of size 400-500 pm composed of sucrose and corn starch):

[0072] Stearic acid is dissolved in ethyl alcohol. The resulting solution is gradually poured onto the support particles using a beaker. The turbine 12 is rotated at approximately 20 rpm. The solution is added for approximately 5 minutes.

[0073] The following steps describe the assembly of Vitamin C, onto the previously prepared carrier particles, using a 30% alcoholic solution of Dewaxed Shellac (DGS).

[0074] Assembly of the active ingredient: phase 1 075] Setting:

[0076] The supply of powdered raw material 26 and the spraying are carried out continuously.

[0077] The spray nozzle 16 is supplied with liquid using a low-pressure tank. The parameters used are as follows:

[0078] ACCURATE type 14 screw powderer. Air “tube” pressure: 0.3 bar. Atomization pressure: 0.2 bar. Liquid flow rate: 1.0 g / s. Powdered raw material feed rate: 2.78 g / s (powder setting: 350). Turbine speed: approx. 20 rpm.

[0079] Initially, spraying is carried out for 3 minutes without adding any powdered raw material (Vitamin C); the addition is then carried out continuously until the quantity of Vitamin C is used up.

[0080] The mass temperature 20 was monitored and maintained at approximately 17°C, which allowed evaporation to be controlled.

[0081] Assembly of the active ingredient: phase 2

[0082] Setting :

[0083] The supply of powdered raw material 26 and the spraying are carried out continuously. The spray nozzle 16 is supplied with liquid using a low-pressure tank. The parameters used are as follows:

[0084] ACCURATE type 14 screw powderer. “Tube” pressure: 0.3 bar. Atomization pressure: 0.2 bar. Liquid flow rate: 1.66 g / s. Powdered raw material feed rate: 7.50 g / s (powder setting: 530). Turbine speed: approx. 20 rpm.

[0085] Initially, spraying is carried out for 3 minutes without adding any powdered raw material (Vitamin C); the addition is then carried out continuously until the quantity of Vitamin C is used up.

[0086] The mass temperature was monitored and maintained at approximately 17°C. This phase is followed by drying with air blowing at 35°C for 6 hours.

[0087] Assembly of the active ingredient: phase 3 0088] Setting:

[0089] The supply of powdered raw material 26 and the spraying are carried out continuously. The spray nozzle 16 is supplied with liquid using a low-pressure tank. The parameters used are as follows:

[0090] ACCURATE type 14 screw powderer. “Tube” pressure: 0.4 bar. Atomization pressure: 0.2 bar. Liquid flow rate: 2.5 g / s. Powdered raw material feed rate: 11.0 g / s (powder setting: 660). Turbine speed: approx. 20 rpm.

[0091] Initially, spraying is carried out for 4 minutes without adding powdered raw material (Vitamin C); the addition is then carried out continuously until the quantity of Vitamin C is exhausted.

[0092] The mass temperature was monitored and maintained at approximately 17°C. This phase is followed by drying with air blowing at 60°C for 12 hours.

[0093] Assembly of the active ingredient: phase 4 0094] Setting:

[0095] The supply of powdered raw material 26 and the spraying are carried out continuously. The spray nozzle 16 is supplied with liquid using a low-pressure tank. The parameters used are as follows:

[0096] ACCURATE type 14 screw powderer. “Tube” pressure: 0.6 bar. Atomization pressure: 0.3 bar. Liquid flow rate: 3.0 g / s. Powdered raw material feed rate: 12.0 g / s (powder setting: 660). Turbine speed: approx. 20 rpm.

[0097] Initially, spraying is carried out for 5 minutes without adding powdered raw material (Vitamin C); the addition is then carried out continuously until the quantity of Vitamin C is exhausted.

[0098] The mass temperature was monitored and maintained at approximately 17°C.

[0099] This phase is followed by drying with air blowing at 60°C for 12 hours.

[0100] Results :

[0101] The appearance of the microgranules obtained is satisfactory and the content test gives a correct result.

[0102] Theoretical content (calculated): 848.0 mg / g Measured content: 823.6 mg / g. Mass Reconciliation: 99.6% Active ingredient yield: 93.8%

[0103] After coating the previous microgranules, the batch is compliant both from a qualitative and quantitative point of view.

[0104] Theoretical content (calculated): 812.1 mg / g Content obtained (measured): 808.5 mg / g Mass Reconciliation: 99.0% Active ingredient yield: 95.7%

Claims

Claims

1. Mounting system (10) by powdering powdered raw material onto support particles, comprising: - a turbine (12) configured to rotate a mass of support particles (20) in a direction of rotation; - a doser (14) configured to introduce at least one powdered raw material (26) into the turbine (12), the doser (14) comprising a feed screw (22) having an end (28) configured to be arranged inside the mass of support particles (20); - a spray nozzle (16) configured to spray a liquid (32) into the turbine (12), the spray nozzle (16) having an outlet (30) configured to be arranged inside the mass of support particles (20), the outlet (30) of the spray nozzle (16) is positioned downstream of the end (28) of the feed screw (22) in the direction of rotation of the mass of support particles (20), so that the powdery raw material (26) coming from the metering device (14) is stirred by the spray nozzle (16) supplying the sprayed liquid (32).

2. The mounting system (10) of claim 1, wherein the spray nozzle (16) and the feed screw (22) extend at a negative angle from the exterior of the turbine (12) to the interior of the turbine (12).

3. A mounting system (10) according to claim 1 or 2, wherein a distance (D) between the outlet (30) of the spray nozzle (16) and the end (28) of the filler screw (22) is between about 100 and 700 mm.

4. A mounting system (10) according to any preceding claim, wherein the spray nozzle (16) and the metering device (14) are each mounted on adjustment means, the adjustment means being disposed outside the turbine (12), the adjustment means being adapted to modify the inclination and height of each of the spray nozzle (16) and the feed screw (22).

5. A mounting system (10) according to any preceding claim, wherein the spray nozzle (16) comprises: - a first orifice (34) configured to spray the liquid (32), - a second orifice (36), annular, coaxial with the first orifice (34), configured to spray compressed air.

6. A mounting system according to claim 5, wherein the spray nozzle (16) comprises a third annular orifice (38), coaxial with the first and second orifices (34, 36), configured to spray compressed air.

7. A mounting system (10) according to any preceding claim, further comprising a probe installed in the turbine (12) and configured to measure the temperature of the rotating mass of support particles (20).

8. Method (100) for mounting by powdering powdered raw material onto support particles, comprising: - introducing a mass of support particles (20) into a turbine (12); - rotating the turbine (12) to move the mass of support particles (20) in the turbine (12) in a direction of rotation; - supplying at least one powdered raw material (26) into the mass of support particles (20) by means of a supply screw (22) comprising one end (28) immersed in the mass of support particles (20); - together with the supply of powdered raw material (26), spraying a liquid (32) into the mass of support particles (20) by means of a spray nozzle (16) comprising an outlet (30) immersed in the mass of support particles (20), downstream of the end (28) of the supply screw (22) in the direction of rotation of the mass of support particles (20).

9. An assembly method (100) according to claim 8, wherein the supply of powdered raw material (26) and the spraying are carried out continuously.

10. A mounting method according to claim 8 or 9, wherein spraying the liquid (32) comprises atomizing the liquid and applying an air tube around the liquid from the spray nozzle (16).

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