System and method for powdering powdered raw material onto rotating support particles in a turbine

Abstract

A powder-coating assembly system (10) for powdering powdered raw material includes: a turbine (12) for rotating a mass of support particles (20) in a direction of rotation; a metering device (14) for introducing at least one powdered raw material (26) into the turbine (12), the metering device (14) including a feed screw (22) having an end (28) configured to be disposed in the mass of support particles (20); A spray nozzle (16) for spraying a liquid (32) into the turbine (12), the spray nozzle (16) having an outlet (30) configured to be disposed in 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) along the direction of rotation of the mass of support particles (20), so that the powdered raw material (26) is mixed by the nozzle supplying the sprayed liquid (32). Abstract figure: Figure 1

Description

Title of the invention: System and method for powdering powdered raw material onto rotating support particles in a turbine technical field

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

[0002] Systems for carrying out the mounting operation by powdering powdered raw material onto rotating support particles typically comprise an open turbine adapted to contain a mass of support particles and 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 the active ingredient are obtained, which can then be further coated.

[0003] In a conventional manner, an operator is responsible for introducing the liquid using a beaker-type container, bringing the powdered raw material using a shovel or similar tool, and manually ensuring the proper distribution of the powdered raw material in the mass of support particles by covering and mixing.

[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 doser, otherwise called a powderer, to supply powdered raw material and to provide a mixing comb and / or a covering shovel to replace manual mixing and covering.

[0005] Thanks to the introduction of these tools, the operator's role consists of manually feeding the doser, regularly adjusting, according to the increase in the mass rotating 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 observed that, as the rotating mass increases throughout the process, several tool adjustments are necessary to maintain a positioning suitable for the proper execution of the operation. The number of tools used complicates access to the vicinity of the turbine opening for regular repositioning.

[0007] Furthermore, the correct positioning of the tools requires a good knowledge of The assembly operation is difficult for an inexperienced operator. Precise tool positioning is necessary to achieve good particle size homogeneity of the microgranules. Summary

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

[0009] Advantageously, the feed screw delivers the powdered raw material by producing an initial mixing of the moving mass. This promotes immediate distribution of the powdered raw material, driven by the speed of the support particles, and significantly limits the dispersion of the powdered material in the air. The spray nozzle then provides a second mixing action, further promoting good distribution of the powdered raw material within the mass of support particles while preventing the support particles or the powdered raw material from sticking to the turbine walls. The appearance of the microgranules obtained using this system is satisfactory, and good distribution of the powdered raw material on the support particles is achieved.The system makes it possible to obtain a consistent and repeatable particle size homogeneity of the microgranules, regardless of the operator's experience and technical skill.

[0010] Optionally, the spray nozzle and the feed screw can extend at a negative angle from the outside of the turbine towards the inside of the turbine. In this way, 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, thus avoiding compaction of the powdered raw material at the end of the feed screw. The spray nozzle can also spray the liquid while minimizing its stress on the rotating mass in the turbine and in the inlet. of the powdered raw material. The distribution of the powdered raw material in the mass of support particles is thereby improved.

[0011] Optionally, the distance between the spray nozzle outlet and the end of the feed screw can be between approximately 100 and 700 mm. The spraying is carried out along the line of arrival of the powdered raw material into the mass of support particles, further improving the mixing of the powdered raw material. This also improves the distribution of the powdered raw material within the mass of support particles.

[0012] Optionally, the spray nozzle and the metering unit can each be mounted on adjustment means, the adjustment means being located outside the turbine. These means are adapted to modify the inclination and height of both the spray nozzle and the feed screw. An operator can thus adjust the positioning of the spray nozzle and the metering unit so that the spray nozzle is correctly aligned with the feed of powdered raw material, possibly with an inclination that minimizes its stress on the rotating mass within the turbine. The operator can make adjustments from outside the turbine, ensuring safe operation and requiring less physical effort and product exposure. The adjustments allow the system to be adapted to the mass of support particles in the turbine and make the system more flexible and adaptable.

[0013] Optionally, the spray nozzle may include: a first orifice configured for spraying liquid, and a second, annular orifice, coaxial with the first orifice, configured for spraying compressed air. This results in atomization of the sprayed liquid at flow rates as low as 0.5 g / s. Atomization is defined as the transformation of a liquid into fine droplets using a pressurized gas, such as compressed air. The mounting system can be adapted to different flow rate ranges, enabling the production of a wide variety of microgranules. This enhances the system's flexibility and adaptability.

[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, protecting it from moving support particles. When the spray nozzle outlet is immersed in the mass, this "tube" forms a dome that atomizes the liquid within the support particles, preventing double particles or overwetting / agglomeration. This ensures proper atomization and 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 particle-support mass in rotation. It is then possible to monitor the regularity of the liquid evaporation by measuring the temperature of the rotating mass. The setup is thus easier to control, and operator intervention is reduced.

[0016] According to another aspect, a mounting method is proposed by powdering powdered raw material onto support particles comprising: - introduce a mass of support particles into a turbine; - to rotate the turbine to move the mass of supporting particles in the turbine along a direction of rotation; - to supply at least one powdery raw material into the mass of support particles by means of a supply screw comprising an end immersed in the mass of support particles; - in conjunction 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 supply screw following the direction of rotation of the mass of support particles.

[0017] Such a process provides initial mixing of the moving mass through the addition of the powdered raw material. This promotes immediate distribution of the powdered raw material, driven by the speed of the support particles, and significantly limits the dispersion of the powdered material in the air. The spray nozzle then provides a second mixing, further promoting the even distribution of the powdered raw material within the mass of support particles while preventing the support particles or the powdered material from sticking to the turbine walls. The appearance of the microgranules obtained from the process is satisfactory, and a content uniformity test demonstrates good distribution of the powdered raw material on the support particles. Therefore, the process is consistent, repeatable, and homogeneous, regardless of the operator's experience and technical skill.

[0018] Optionally, the feeding of powdered raw material and the spraying can be carried out continuously. The process does not require any rest periods that would allow the operator to successively perform stirring, covering, and / or feeding of powdered raw material. Furthermore, the sprayed liquid evaporates during the execution of the process, and it is not necessary to interrupt it to allow for evaporation. 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 atomization and the air tube produces a spray within the support particles that does not generate double particles or a superposition phenomenon. anchorage / agglomeration. Brief description of the drawings

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

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

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

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

[0024] [Fig.4] schematically illustrates a side view of a spray nozzle that can 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 [Fig. 4], Fig. 6

[0026] [Fig.6] illustrates a flowchart of assembly process according to an 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 [Fig.1] and / or the mounting method of [Fig.6] according to one embodiment. Description of the implementation methods

[0029] Figure 1 schematically illustrates a mounting system 10 for powdering powdered raw material onto support particles to form microgranules of active ingredient, which can then be further coated. Any type of powdered raw material, including both excipients and active ingredients, can be mounted onto support particles using the system according to the invention. Examples of active ingredients include Diltiazem, Vitamin C, Ketoprofen, Morphine, Secnidazole, and Theophylline.

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

[0031] The turbine 12 comprises a cylindrical casing delimited by a lateral wall 18 and mounted on supports (not shown). The cylindrical casing forms a container adapted to receive a batch of support particles 20. The turbine 12 can 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 supports to rotate about an axis of rotation X. In the illustrated example, the rotation is clockwise, but it could also be counterclockwise. The rotation of the turbine 12 about its axis of rotation X causes the mass of support particles 20 to rotate in a direction of rotation. The mass of support particles 20 moves within the turbine 12 along 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 to the bottom of the turbine 12 and mixing.

[0033] The rotation axis X of the turbine 12 is inclined with respect 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 at the bottom of the turbine 12.

[0034] As more visible in [Fig.2], the doser 14 includes a feed screw 22 and a reservoir 24.

[0035] The reservoir 24 allows for the storage of 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 reservoir 24 may have a storage capacity of between 5 and 100 kg of powdered raw material 26, preferably between 15 and 50 kg. It is thus possible to produce a large volume of microgranules of the active ingredient, which can then be coated, without an operator needing to refill the reservoir 24 too frequently or continuously.

[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 conveys the powdered raw material 26 from the reservoir 24 to the inside of the turbine 12. The powdered 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 an initial mixing of the moving mass 20, which promotes an immediate distribution of the powdered 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 with 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 inclination angle between 2° and 45°, preferably between 10° and 35° with a horizontal axis. Thus, the powdered raw material 26 is directly carried by the movement of the support particles in the turbine 12. The feed screw 22 can deliver the powdered raw material 26 into the mass of support particles 20 without generating stresses, avoiding compaction of the powdered 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 feeding 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 powdered raw materials 26, without compaction of the powdered raw material occurring at the end 28 of the feed screw 22.

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

[0041] The spray nozzle 16 is supported from the outside of the turbine 12 by a a support arm or any other means up to an outlet 30 inside the turbine 12, so as to spray a liquid 32 into the mass of support particles 20. The liquid 32, or solution, or suspension, can be any liquid that promotes good adhesion of the powdered 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 used with the system according to the invention. As an example, shellac in alcoholic solution may be mentioned. Spraying the liquid 32 into the mass of support particles 20 provides a second mixing action. further ensuring the proper distribution of the powdered raw material 26 in the mass of support particles 20. Spraying into the mass 20 also prevents the support particles or the powdered raw material from sticking to 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, following the direction of rotation of the support particles in the turbine 12. Therefore, viewed 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 of 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 of 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 material delivery line first powder 26 coming from the end 28 of the feed screw 22.The spraying contributes to the proper 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 mixing motion generated by the end 28 of the feed screw 22. Consequently, the liquid 32 can be sprayed close to the arrival line of the powdered material 26, improving its mixing and the adhesion of the powdered raw material 26 to the support particles.

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

[0045] As more clearly seen in [Fig. 4], the spray nozzle 16 has a length L greater than 200 mm. Thus, the spray nozzle 16 has sufficient length L for the outlet 30 of the spray nozzle 16 to be immersed in the mass of support particles 20, even when the latter is small (e.g., 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 mass of support particles 20. movement, even when the mass reaches 300 kg or 350 kg.

[0046] As more clearly seen in [Fig. 5], the spray nozzle 16 is a tri-fluid nozzle. The outlet 30 of the nozzle 16 includes 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 includes 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 exiting the second orifice 36 atomize the liquid 32 exiting the first orifice 34 into fine droplets.

[0047] The first orifice 34 has, for example, a diameter of 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 by 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 accommodate different flow rates and liquids to be sprayed. The pressure and / or air flow rate of the orifice 36 will be adjusted to ensure appropriate 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 includes 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 support particles. The air from the third orifice 38 slightly moves the support particles away from the outlet 30 of the nozzle 16 to prevent them from clumping together and to keep them at a sufficient distance to allow the atomization of the liquid 32.

[0049] The spray nozzle 16 and the metering unit 14 can be mounted from outside the turbine 12 on adjustment means (not shown). For example, the spray nozzle 16 can be supported by an arm connected to a gantry. Any other type of adjustment means accessible to a person skilled in the art can be provided. The adjustment means allow the spray nozzle 16 and the feed screw 22 to be adjusted respectively to ensure proper 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 allow the spray nozzle 16 and the feed screw 22 to be positioned to ensure a supply of liquid 30 and powdered raw material 16 to the front third of the support particle mass 20. The operator can make the adjustments from outside the turbine 12, without any special knowledge.According to one example, the adjustment means may include visual indicators to further facilitate the correct positioning of the nozzle. 16 and the feed screw 22.

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

[0051] A method for mounting 100 of powdered raw material onto 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 particles 20 is introduced into the turbine 12. The mass of support particles 20 introduced into the turbine 12 can, for example, be between 20 kg and 350 kg. In step 110, the support particles are in the form of small-diameter microgranules 40 free of powdered raw material 26 (see [Fig. 7]). The support particles can 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 rotational speed of the turbine 12 is, for example, between 15 and 30 rpm, preferably between 20 and 25 rpm. The rotational speed can be constant or can be modulated during the process according to changes in the size of the support particles and / or the increase in the rotating mass in the turbine. The support particles are driven along the side wall 18 of the turbine 12 before falling to the bottom of the turbine 12 and mixing.

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

[0055] According to a fourth step 140, carried out in conjunction 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, through 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 powdered raw material 26 within the mass 20. The liquid 32 can be sprayed at a flow rate between 0.1 g / s and 6 g / s, preferably between 0.5 g / s and 3 g / s, depending on the requirements for carrying out different microgranule formulations.

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

[0057] The spraying process also includes, here, a substep 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 as to slightly repel the carrier particles from the outlet 30 of the spray nozzle 16 and allow the atomization of the liquid 32.

[0058] The above process 100 can be carried out continuously until the powdered raw material 26 is exhausted. The spraying and feeding of the powdered raw material are performed without interruption. It is not necessary to allow rest periods for an operator to work on the mass of support particles 20, nor to allow the liquid 32 to evaporate. The efficiency of process 100 is thus improved.

[0059] Following 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 powdered raw material 26. The coated microgranules 42 obtained are, for example, visible in [Fig. 8], in which the powdered raw material 26 has been mounted on the support particles 40 visible in [Fig. 7], taken at the same magnification as [Fig. 8]. Good particle size homogeneity is observed in the coated microgranules 42.

[0060] The process 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 execution of the process 100 (alignment and orientation of the nozzle and screw as described above). Occasionally, positioning adjustments may be made during the process 100, particularly when the mass in the turbine 12 has increased considerably. However, these adjustments are minor and do not require significant physical effort or specialized 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. Examples of preparation

[0062] Example 1: Preparation of Theophylline microgranules. Materials Quantity in kg Theophylline 35.03 Neutrals #30 (400-600 pm) 42.02 40% Alcoholic Solution of Dewaxed and Bleached Shellac 12.60

[0063] Mounting of Théophylline on support particles (here neutral particles of size 400-600 pm composed of sucrose and corn starch) using an alcoholic solution of 40% bleached dewaxed shellac.

[0064] Parameterization: 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 (a container holding the liquid to be sprayed and maintained at a pressure generally below 4 bar by the use of a gas such as compressed air to ensure a steady flow of liquid through the pipe leading to the spray nozzle 16). The pressure in this tank is also known as the spray pressure. The parameters used are as follows:

[0065] ACCURATE type screw powder dispenser 14. 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 (dust applicator setting: 900). Turbine speed: approx. 20 rpm.

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

[0067] The temperature of mass 20 was monitored to control the evaporation of liquid 32. After 1 hour of spraying, a dryer blowing air at 25 °C into turbine 12 was added. This stabilized the temperature of mass 20 and thus allowed continued control of evaporation. The dryer was then positioned to blow air 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 powdery raw material 26. Theoretical (calculated) content: 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, i.e. a CV of 0.7%.

[0069] Example 2: Preparation of Vitamin C microgranules

[0070] Preparation of the support particles:

[0071] Conventionally, in turbine 12, support particles (here, neutral particles of size 400-500 µm composed of sucrose and corn starch): Materials Quantity in kg Neutrals Sp (400-500 pm) 28.05 Stearic acid 0.017 Ethyl alcohol 96% 0.15

[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 duration of the solution application is approximately 5 minutes.

[0073] The following steps describe the mounting of Vitamin C, on the previously prepared support particles, using a 30% alcoholic solution of Dewaxed Shellac (GLD).

[0074] Assembly of the active ingredient: phase 1 Ingredients Quantity in kg Vitamin C 30.00 Alcoholic solution of 30% GLD 10.66 Tartaric acid (1.25% vs GLD) 0.040

[0075] Parameterization:

[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 screw powder dispenser 14. Air tube pressure: 0.3 bar. Atomization pressure: 0.2 bar. Liquid flow rate: 1.0 g / s. Powdered raw material supply rate: 2.78 g / s (dust applicator setting: 350). Turbine speed: approx. 20 rpm.

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

[0080] The mass temperature 20 was monitored and maintained at approximately 17 °C, which allowed for control of evaporation.

[0081] Assembly of the active ingredient: phase 2 Ingredients Quantity in kg Vitamin C 42.50 Alcoholic solution at 30% GLD 10.96 Tartaric acid (1.25% vs GLD) 0.041

[0082] Parameterization:

[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 screw powder dispenser 14. Tube pressure: 0.3 bar. Atomization pressure: 0.2 bar. Liquid flow rate: 1.66 g / s. Powdered raw material supply rate: 7.50 g / s (dust applicator setting: 530). Turbine speed: approx. 20 rpm.

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

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

[0087] Assembly of the active ingredient: phase 3 Ingredients Quantity in kg Vitamin C 102.50 Alcoholic solution at 30% GLD 23.12 Tartaric acid (1.25% vs GLD) 0.087

[0088] Parameterization:

[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 screw powder dispenser 14. 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 (dust applicator setting: 660). Turbine speed: approx. 20 rpm.

[0091] Initially, the spraying is carried out for 4 minutes without the addition of 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 was followed by drying with air blowing at 60 °C for 12 hours.

[0093] Assembly of the active ingredient: phase 4 Ingredients Quantity in kg Vitamin C 99.84 Alcoholic solution at 30% of GLD 25.00 Tartaric acid (1.25% vs GLD) 0.094

[0094] Parameterization:

[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 screw powder dispenser 14. Tube pressure: 0.6 bar. Atomization pressure: 0.3 bar. Liquid flow rate: 3.0 g / s. Powdered raw material supply rate: 12.0 g / s (dust applicator setting: 660). Turbine speed: approx. 20 rpm.

[0097] Initially, the spraying is carried out for 5 minutes without the addition of 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. This phase is followed by drying with air blowing at 60°C for 12 hours.

[0099] Results:

[0100] The appearance of the microgranules obtained is satisfactory and the content test gives a correct result.

[0101] Theoretical (calculated) content: 848.0 mg / g Measured content: 823.6 mg / g. Mass reconciliation: 99.6% Yield of active ingredient: 93.8%

[0102] After coating the previous microgranules, the batch is compliant from both a qualitative and quantitative point of view.

[0103] Theoretical (calculated) content: 812.1 mg / g Content obtained (measured): 808.5 mg / g Mass reconciliation: 99.0% Active ingredient yield: 95.7%

Claims

Demands

1. Assembly system (10) for 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 metering device (14) configured to introduce at least one powdered raw material (26) into the turbine (12), the metering device (14) comprising a feed screw (22) having an end (28) configured to be disposed 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 disposed 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) along the direction of rotation of the mass of support particles (20), so that the powdery raw material (26) from the metering unit (14) is mixed by the spray nozzle (16) bringing the sprayed liquid (32).

2. Mounting system (10) according to claim 1, wherein the spray nozzle (16) and the feed screw (22) extend at a negative inclination from the outside of the turbine (12) towards the inside of the turbine (12).

3. 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 feed screw (22) is between approximately 100 and 700 mm.

4. Mounting system (10) according to any one of the preceding claims, 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. Mounting system (10) according to any one of the preceding claims, 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. Mounting system according to claim 5, wherein the spray nozzle (16) includes a third orifice (38), annular, coaxial with the first and second orifices (34, 36), configured to spray compressed air.

7. Mounting system (10) according to any one of the preceding claims, further comprising a probe installed in the turbine (12) and configured to measure the temperature of the rotating support particle mass (20).

8. Method (100) of 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 feed screw (22) having an end (28) immersed in the mass of support particles (20); - in conjunction with the supply of powdered raw material (26), spray 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) following the direction of rotation of the mass of support particles (20).

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

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

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