Rotary valve and processing plant equipped with a rotary valve

Abstract

The present invention relates to a processing plant (2) for metering, feeding, and / or discharging granules without pulsation, having a rotary valve (1) for metering, feeding, and / or discharging granules, a granulator (3), and a rotary valve (1) connected to the discharge section of the granulator (3).

Description

Technical Field

[0001] The present invention relates to a rotary valve for metering, feeding, and / or discharging granules, which rotary valve includes a casing, in which an internal space is formed that is bounded by a casing wall having a cylindrical inner wall surface and has a central central axis, wherein the casing has, in an inlet zone, an inlet unit with an inlet opening that opens into the internal space, and, in a circumferential direction of the central axis, in a discharge zone spaced from the central axis, a discharge unit with an outlet opening that likewise opens into the internal space, the casing has a rotor, the rotor is arranged in the internal space and is rotatable while performing a conveying rotational movement about a rotational axis that coincides with the central axis, and includes rotary vanes that extend radially from the central axis toward the inner wall surface, wherein a rotary chamber for accommodating granules is formed between each two successive rotary vanes, and the granules move from the inlet zone to the discharge zone during the conveying rotational movement, relating to the invention of such a rotary valve.

[0002] Furthermore, the present invention relates to a processing plant for metering, feeding, and / or discharging granules without pulsation, having a granulator and a rotary valve connected to a discharge part of the granulator.

Background Art

[0003] In tablet manufacturing, especially in the continuous manufacturing of hard dosage forms, also known as solids, rotary valves are used for the process step of metering, feeding, and / or discharging granules.

[0004] Patent Document 1 (WO 2020 / 156750 A1) discloses this type of rotary valve. This rotary valve includes a casing having at least one inlet unit and at least one outlet unit, in which a rotationally driven rotor is arranged. This rotationally driven rotor has a plurality of cell walls, which extend substantially in the radial direction and circumferentially delimit the cells of the rotor. At this time, at least the cell walls of the rotor are formed of an elastic and flexible material, and each two adjacent cell walls are connected to each other by each cell bottom in the region of their radially inner ends. As a result, the cell bottom of the rotor is formed of an elastic and flexible membrane, which is connected to two adjacent cell walls respectively in the region of the radially inner end, and overlaps the cavities arranged radially inside each membrane.

[0005] Patent Document 2 (DE102004044217B4) also discloses a rotary valve. This rotary valve includes a casing having a casing cover closing the end face and a rotor. This casing includes an internal space bounded by a substantially cylindrical inner wall, an upper inlet opening into the internal space, a lower outlet opening out of the internal space, a central axis, and an end face delimiting the boundary of the internal space. The casing cover is attached to the casing and has a storage opening concentric with the central axis. The rotor is arranged concentrically with respect to the central axis, is arranged through the storage opening and supported for rotational processing, and has vanes. These vanes extend radially with respect to the central axis to the vicinity of the inner wall and extend in the direction of the central axis to the vicinity of the housing cover. At this time, each casing cover has at least one groove-shaped recess that opens toward the internal space and extends radially with respect to the central axis from each storage opening beyond the vanes to the outlet beyond the vanes.

[0006] The disadvantage of the rotary valve known from the prior art is that the rotary valve is not suitable for performing further process steps required in tablet manufacturing.

Prior Art Documents

Patent Documents

[0007]

Patent Document 1

Patent Document 2

Summary of the Invention

Problems to be Solved by the Invention

[0008] Therefore, an object of the present invention is to overcome the disadvantages of the prior art and provide a rotary valve that is suitable for performing further process steps for tablet manufacturing in addition to dosing, charging, and discharging of granules.

Means for Solving the Problems

[0009] This object is achieved in a rotary valve of the above-mentioned type having a sieve wall portion formed as a sieve in the region of the outlet opening and having a casing wall extending beyond the outlet opening. By the sieve, further processing of the granules is made possible by crushing and sieving the granules. Advantageously, the rotary valve performs not only the dosing, charging, and discharging of the granules but also the process steps of sieving and crushing the granules. Furthermore, by sieving and crushing the granules, it is possible to improve the dosing, particularly from a very small mass flow, by the rotary valve.

[0010] The sieve may be formed in different embodiments. For example, in the form of a mesh sieve or as a metal insert, preferably as a metal sheet insert or a steel insert.

[0011] According to an advantageous form in this regard of the rotary valve, the sieve is removable and / or replaceable. By replacing the sieve, it is possible to install sieves with different mesh sizes in the rotary valve, and thus it is possible to adapt the particle size to the process requirements. Even when the sieve is worn out, the sieve can be replaced. In addition, since the sieve is removable, it is ensured that the sieve can be easily cleaned. When the sieve is not required, the sieve can be removed, or, for example, a simple frame can be used.

[0012] According to a developed form of the rotary valve, the inner wall surface is at least partially formed as a sealing surface, and / or each rotary vane has a vane surface that is at least partially formed as a sealing surface. By forming the sealing surface, the pressure difference between the input side and the discharge side can be effectively separated from each other.

[0013] According to a further developed form of the rotary valve, the rotary valve comprises a drive unit for converting the rotary motion into a conveying rotary motion. Preferably, the drive unit is suitable for performing a constant conveying rotary motion or an alternating conveying rotary motion. Here, the alternating conveying rotary motion has a rotation of the rotor in the conveying direction (forward movement) and a subsequent rotation of the rotor in the direction opposite to the conveying direction (backward movement) following this rotation, and at this time, the degree of rotation of the rotor in the conveying direction is greater than the degree of rotation of the rotor in the direction opposite to the conveying direction. At the same time, the conveying rotary motion needs to be always considered in relation to the sieve length. Preferably, the rotation of the rotor in the conveying direction is performed by an angle α, and the subsequent rotation of the rotor in the direction opposite to the conveying direction following this rotation is performed by an angle β, and the angle α is greater than the angle β. Thereby, the sieving process and the crushing process of the particles are improved, and the emptying of the rotary chamber is surely improved. Preferably, the angle α has an angular dimension of 5° to 30°, the angle β has an angular dimension of 5° to 25°, and preferably, the angle α has an angular dimension of 10°, and the angle β has an angular dimension of 5°.

[0014] Furthermore, the rotary vane is formed such that the rotary chamber forms a multi-start screw-shaped spiral space. The multi-start screw-shaped spiral space of the rotary chamber achieves a uniform mass flow by appropriate superposition of the rotary chambers through the sieve, and thus improves the metering of the granules by the rotary valve. The wider the rotary is formed, the more advantageous the influence of the multi-start screw-shaped spiral space of the rotary chamber on the uniform mass flow.

[0015] Preferably, the inlet zone and the discharge zone are arranged asymmetrically with respect to each other within the casing. By arranging the inlet zone and the discharge zone asymmetrically with respect to each other, preferably, the filling of the cell chamber having a multi-start screw-shaped spiral arrangement is optimized.

[0016] In a further development of the rotary valve, the rotary chamber has a cross-section formed asymmetrically. The asymmetrically formed cross-section of the rotary chamber has a positive effect on, on the one hand, optimally filling the rotary chamber on the inlet side and, on the other hand, emptying the rotary chamber on the discharge side.

[0017] According to a further development of the rotary valve, the rotary valve has at least one nozzle device for emptying each rotary chamber by compressed air control. The nozzle device improves the emptying of the rotary chamber. In this regard, the nozzle device is formed to enable the injection of angularly controlled compressed air in the region of the sieve wall portion.

[0018] This problem is further solved in a system of the type described at the beginning, wherein the rotary valve is formed as the rotary valve according to any one of claims 1 to 13. Advantageously, such a processing plant is suitable for producing the required granules and metering them according to the processing requirements for further processing during the production of tablets, in particular in the continuous production of solid dosage forms.

[0019] According to an advantageous embodiment in this regard, the granulator is formed as a fluidizing device, preferably as a vortex bed device or a jet fluidized bed device.

[0020] The present invention will be described in more detail below with reference to the accompanying drawings.

Brief Description of the Drawings

[0021]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Figure 7

Embodiments for Carrying Out the Invention

[0022] Unless otherwise specified, the following description relates to all embodiments of the rotary valve 1 for metering, feeding, and / or discharging granules, and the processing plant 2 equipped with the rotary valve 1, as depicted in the drawings.

[0023] The processing plant 2 has a rotary valve 1 downstream of the granulator 3. Here, the granulator 3 is preferably configured as a high-shear granulator 4, as a roller compactor, or in particular as a fluidization device formed as a vortex bed device or a jet fluidized bed device. The rotary valve 1 is arranged upstream of a dryer 5, in particular a vortex bed dryer 6, and is connected to this dryer 5 by means of a line 7, preferably a flexible hose connection 59. The processing plant 2 having the rotary valve 1 is suitable for ensuring a pulsation-free metering, feeding, and / or discharging of the granules into the dryer 5.

[0024] The rotary valve 1 comprises a casing 9 with a casing wall 8 having at least a substantially cylindrical internal space 10, wherein the internal space 10 is delimited by a cylindrical inner wall surface 11. Furthermore, the internal space 10 has a central axis 12. The internal space 10 of the casing 9 is open at its end faces 13, 14, which are covered by casing covers 15, 16 respectively, which are removably fixed to the casing 9 by means of screws (not shown).

[0025] The feed unit 19, which is arranged in the feed zone 17 and has an inlet opening 18, opens into the internal space 10 from above. In the discharge zone 20, which is spaced circumferentially from the central axis 12, a discharge unit 22 is arranged, which likewise has an outlet opening 21 opening into the internal space 10.

[0026] The casing wall 8 extends beyond the outlet opening 21 and has a sieve wall portion 24, which is formed as a sieve 23 in the region of the outlet opening 21. The sieve 23 is preferably removable and / or replaceable. In the first embodiment of the rotary valve 1 depicted in FIG. 3, the sieve 23 extends radially within the casing wall 8 and has holes 26, which are formed as hole portions 25. In the second embodiment of the rotary valve 1 depicted in FIG. 6, the holes 26, which are formed as hole portions 25, extend axially with respect to the longitudinal central axis 27 of the rotary valve 1.

[0027] The sieve 23 can be formed in different embodiments. For example, it can be in the form of a mesh sieve or as a metal insert, preferably as a thin metal sheet insert or a steel insert.

[0028] By replacing the sieve 23, it is possible to install sieves 23 with different mesh sizes in the rotary valve 1, and thus it is possible to adapt the particle size of the granular material to the process requirements. Typical mesh sizes range from 0.1 mm to 2 mm, particularly in the range of 1.0 mm to 1.5 mm.

[0029] Furthermore, the holes 25 formed as the holes 26 may preferably have different shapes. The holes 25 may have forms such as, for example, square, circular, elliptical, parallelogram, etc. Furthermore, the sieve 23 may have holes 25 of different shapes.

[0030] Even when the sieve 23 is worn out, the sieve can be replaced. In addition, since the sieve 23 can be removed, it is ensured that the sieve can be easily cleaned. When the sieve 23 is not required, the sieve can be removed, or, for example, a simple frame (not shown) can be used.

[0031] Advantageously, the rotary valve 1 performs not only the processes of metering, feeding, and discharging the granules, but also the process steps of sieving and crushing the granules. Furthermore, by sieving and crushing the granules, it is possible to improve the metering of a small mass flow, particularly by the rotary valve 1.

[0032] In the first embodiment of the rotary valve 1 depicted in FIG. 3, the inlet zone 17 is disposed on the upper half side 28 of the rotary valve 1, and the discharge zone 20 is disposed on the lower half side 29 of the rotary valve 1. The inner wall surfaces 30, 31 of the inlet unit 19 extend parallel to the longitudinal central axis 27 and extend vertically from the upper side 57 to the lower side 58. The inner wall surface 32 of the discharge unit 22 extends obliquely with respect to the longitudinal central axis 27 from the upper side 57 to the lower side 58 of the rotary valve 1, while the inner wall surface 33 extends vertically from the upper side 57 to the lower side 58 and parallel to the longitudinal central axis 27. Accordingly, the discharge region 34 of the discharge unit 22 is smaller than the projection region 35 of the outlet opening 21.

[0033] The inlet zone 17 and the discharge zone 20 are arranged at least partially offset from each other across the width 36 of the rotary valve 1. As a result, the inlet zone 17 and the discharge zone 20 are arranged asymmetrically with respect to each other within the casing 9.

[0034] In contrast, as shown in the second embodiment of the rotary valve 1 in FIG. 6, the inlet zone 17 and the discharge zone 20 are arranged vertically at the center of the rotary valve 1. The inner wall surfaces 30, 31 of the inlet unit 19 are conical and converge from the upper side 57 to the lower side 58 of the rotary valve 1. Accordingly, the inlet surface 37 of the inlet unit 19 is larger than the protruding surface 38 of the inlet opening 18. The inner wall surfaces 32, 33 of the discharge unit 22 are conical and branch from the upper side 57 to the lower side 58 of the rotary valve 1. Accordingly, the discharge surface 34 of the discharge unit 22 is larger than the protruding surface 35 of the discharge opening 21. Accordingly, the inlet unit 19 and the discharge unit 22, as well as the inlet zone 17 and the discharge zone 20, are formed symmetrically with respect to the mirror axis 39 within the casing 9.

[0035] In the internal space 10, a rotary 42 is arranged which can rotate about a rotation axis 40 coinciding with the central axis 12 while performing a conveying rotational movement 41. The rotary 42 is arranged in the internal space 10 in an exchangeable manner. The shaft 46 of the rotary 42, which is driven by a drive unit 43, preferably by a motor 44, preferably by an electric motor or a torque motor 45, is rotatably supported by bearings (not shown) formed in the casing covers 15, 16 through bearing openings (not shown) formed in the casing covers 15, 16. Further, the rotary 42 has rotary vanes 47 extending radially from the central axis 12 towards the inner wall surface 11.

[0036] A cellular wheel chamber 48 for accommodating granules is formed between each of two consecutive rotary vanes 47. The rotary 42 has a plurality of rotary chambers 48, preferably 3 to 25 rotary chambers 48. The rotary chambers 48 move in the conveying direction 49 from the input zone 17 to the discharge zone 20. By arranging the input zone 17 and the discharge zone 20 asymmetrically with respect to each other, the filling of the cell chambers 48 is optimized. Each rotary chamber 48 accommodates granules under the input unit 19, and in the discharge unit 22, the granules are conveyed through a sieve wall portion 24 formed as a sieve 23. Thereby, the granules can be volumetrically and continuously conveyed preferably at a speed of 1 to 100 rpm of the rotary 42. The conveying capacity is determined by the content of the granules in the rotary chamber 48 and the speed of the rotary 42.

[0037] As shown in FIGS. 2 and 4, the rotary vane 47 of the first embodiment of the rotary 42 is formed such that the rotary chamber 48 forms a multi-start helical space 50 in the direction of the axis of rotation 40. The multi-start helical space 50 of the rotary chamber 48 allows for a uniform mass flow to be achieved by appropriately superimposing the rotary chamber 48 over the sieve 23, and thus improves the metering of the granules by the rotary valve 1. Preferably, the space 50 has an asymmetrically formed cross-section 51. The wider the rotary 42 is formed, the more advantageous the effect of the multi-start helical space 50 of the rotary chamber 48 on the uniform mass flow.

[0038] In contrast to the first embodiment of the rotary 42, the rotary vane 47 of the second embodiment of the rotary 42 depicted in FIG. 7 is formed such that the space 50 formed between two consecutive rotary vanes 47 takes the form of a semi-cylindrical shape. Thus, as shown in FIG. 6, the cross-section 51 of the rotary chamber 48 is formed in a semi-circular shape.

[0039] The drive unit 43 is preferably configured to provide a constant conveying rotational movement 41 of the rotary 42. Such a conveying rotational movement 41 is realized in the first embodiment. The arrangement of the rotary chamber 48 during the constant conveying rotational movement 41 is preferably selected such that at least two rotary chambers 48 are at least partially in contact with the sieve 23 at any point in time during the conveying rotational movement 41. This can suppress the pulsation of the mass flow.

[0040] Optionally, the drive unit 43 is suitable for generating a conveying rotational movement 41, which is preferably formed as an alternating conveying rotational movement 41. Such a conveying rotational movement 41 is realized in the second embodiment. Here, the alternating conveying rotational movement 41 has a rotation (forward movement) of the rotor 42 in the conveying direction 49 and, following this rotation, a rotation (backward movement) of the rotor 42 in the direction opposite to the conveying direction 49. In the alternating conveying rotational movement 41, it is preferable that the degree of rotation (forward movement) of the rotor 42 in the conveying direction 49 is greater than the degree of rotation (backward movement) of the rotor 42 in the direction opposite to the conveying direction 49. At the same time, the conveying rotational movement 41 always needs to be considered in relation to the length 60 of the sieve. Even in the case of an alternating conveying rotational movement 41, the arrangement of the rotary chambers 48 is preferably selected such that at least two rotary chambers 48 are at least partially in contact with the sieve 23 at any point during the conveying rotational movement 41. Thereby, pulsation of the mass flow can be suppressed.

[0041] For example, in the case of an alternating conveying rotational movement 41 and a sieve length 60 of 60 mm, the forward movement is 60 mm and the backward movement is 45 mm. Other values for the forward movement and / or the backward movement are also possible. Thus, after one cycle, i.e., one forward movement and one backward movement, the rotor 42 rotates substantially 15 mm in the conveying direction 49. Thereby, the same sieve surface 61 is always used and it is prevented that the same sieve surface 61 is always cleaned again by the backward movement.

[0042] This, of course, results in angles, namely an angle α for forward movement and an angle β for backward movement. Thus, the alternating conveying rotational movement 41 also particularly means rotating the rotary 42 by the angle α in the conveying direction 49 and then rotating the rotary 42 in the direction opposite to the conveying direction 49 by the angle β, and the angle α is larger than the angle β. This improves the screening process and crushing process of the granules and surely improves emptying the rotary chamber 48. Preferably, the angle α has an angular dimension of 5° to 30°, the angle β has an angular dimension of 5° to 25°, and particularly preferably, the angle α has an angular dimension of 10° and the angle β has an angular dimension of 5°. The angular dimensions of the angles α and β are preferably selected such that at least two spaces 50 are at least partially in contact with the screen 23 at each point in time during the conveying rotational movement 41. Thereby, the pulsation of the mass flow can be suppressed.

[0043] By selecting the drive unit 43, the conveying rotational movement 41 can be determined, and in particular, a constant conveying rotational movement 41 or an alternating conveying rotational movement can be selected. The drive unit can also be configured to produce a constant conveying rotational movement 41 of the rotary 42 on the one hand and an alternating conveying rotational movement 41 on the other hand.

[0044] By forming the sealing surfaces 52, 53, the pressure difference generated between the input unit 19 and the discharge unit 22 can be effectively separated from each other, and accordingly, two different pressure levels can be maintained. As an example, in the first embodiment of the rotary valve 1 shown in FIG. 3, the inner wall surface 11 is at least partially formed as the sealing surface 52, and each rotary vane 47 has a vane surface 54 that is at least partially formed as the sealing surface 53. In the half-section of the second embodiment of the rotary valve 1 shown in FIG. 6, only the inner wall surface 11 has the sealing surface 52.

[0045] In a second embodiment of the rotary valve 1 shown in FIG. 6, two different possibilities are shown by way of example for emptying the rotary chamber 48 by compressed air control, with at least one nozzle device 55.

[0046] In a first embodiment, the rotor 42 has a nozzle device 55 for emptying each rotary chamber 48 in the form of a plurality of nozzles 56 arranged within the rotary vane 47.

[0047] In a second embodiment, the casing cover 15 has a nozzle device 55, in particular in the form of nozzles 56 for emptying each rotary chamber 48. Particularly preferably, the nozzle device 55 is formed so as to enable an angularly controlled injection of compressed air in the region of the sieve wall portion 24. Here, it is particularly preferred for the nozzles 56 to be arranged within the casing covers 15, 16 for each rotary chamber 48 arranged simultaneously above the sieve wall portion 24. For example, if two rotary chambers 48 are simultaneously located above the sieve 23, preferably compressed air can be blown into both through the nozzles 56.

Claims

1. A rotary valve (1) for metering, introducing, and / or discharging granules, the rotary valve (1) comprises a casing (9), within which an internal space (10) is formed, bounded by a casing wall (8) having a cylindrical inner wall surface (11) and having a central central axis (12), the casing (9) has, in an inlet zone (17), an inlet unit (19) with an inlet opening (18) opening into the internal space (10), and, in a circumferential direction of the central axis (12), in a discharge zone (20) spaced from this central axis, a discharge unit (22) with an outlet opening (21) likewise opening into the internal space (10), a rotor (42) is provided, the rotor (42) is arranged in the internal space (10) and is rotatable while performing a conveying rotational movement (41) about a rotational axis (40) coinciding with the central axis (12), and comprises rotor vanes (47) extending radially from the central axis (12) towards the inner wall surface (11), between each two successive rotor vanes (47), a rotor chamber (48) for accommodating granules is formed, and this rotor chamber (48) moves from the inlet zone (17) to the discharge zone (20) during the conveying rotational movement (41), in the rotary valve (1), the casing wall (8) extends beyond the outlet opening (21) and has a sieve wall portion (24) formed as a sieve (23) in the region of the outlet opening (21), characterized in that the rotary valve (1).

2. The rotary valve (1) according to claim 1, characterized in that the sieve (23) is removable and / or replaceable.

3. The rotary valve (1) according to claim 1 or 2, characterized in that the inner wall surface (11) is at least partially formed as a sealing surface (52) and / or each rotor vane (47) has a vane surface (54) at least partially formed as a sealing surface (53).

4. The rotary valve (1) according to any one of claims 1 to 3, characterized in that the rotary valve (1) comprises a drive unit (43) for causing the rotor (42) to perform the conveying rotational movement (41).

5. The rotary valve (1) according to claim 4, characterized in that the drive unit (43) is suitable for performing a constant conveying rotational movement (41) or an alternating conveying rotational movement (41).

6. The alternating conveying rotational movement (41) has the rotation of the rotor (42) in the conveying direction (49) and the subsequent rotation of the rotor (42) in the direction opposite to the conveying direction (49) following this rotation, The rotary valve (1) according to claim 5, characterized in that the degree of rotation of the rotor (42) in the conveying direction (49) is greater than the degree of rotation of the rotor (42) in the direction opposite to the conveying direction (49).

7. The rotation of the rotor (42) in the conveying direction (49) is performed by an angle α, and the subsequent rotation of the rotor (42) in the direction opposite to the conveying direction (49) following this rotation is performed by an angle β, The rotary valve (1) according to claim 6, characterized in that the angle α is greater than the angle β.

8. The angle α has an angular dimension of 5° to 30°, and the angle β has an angular dimension of 5° to 25°, The rotary valve (1) according to claim 7, preferably characterized in that the angle α has an angular dimension of 10° and the angle β has an angular dimension of 5°.

9. The rotary valve (1) according to any one of claims 1 to 8, characterized in that the rotary vane (47) is formed such that the rotary chamber (48) forms a multi-start screw-shaped spiral space (50).

10. The rotary valve (1) according to any one of claims 1 to 9, characterized in that the inlet zone (17) and the outlet zone (20) are arranged asymmetrically with respect to each other within the casing (9).

11. The rotary valve (1) according to any one of claims 1 to 10, characterized in that the rotary chamber (48) has a cross-section (51) formed asymmetrically.

12. The rotary valve (1) according to any one of claims 1 to 11, characterized in that it has at least one nozzle device (55) for emptying the rotary chamber (48) by compressed air control.

13. The rotary valve (42) has a nozzle device (55) for emptying each rotary chamber (48) and / or the casing covers (15, 16) have a nozzle device (55) for emptying each rotary chamber (48), characterized in that the rotary valve (1) according to claim 12.

14. A processing plant (2) for metering, feeding, and / or discharging granules without pulsation, having a granulator (3) and a rotary valve (1) connected to the discharge part of the granulator (3), characterized in that the rotary valve (1) is formed as the rotary valve (1) according to any one of claims 1 to 13.

15. The processing plant according to claim 14, characterized in that the granulator (3) is formed as a fluidization device, preferably as a vortex bed device or a spouted bed device.

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