Rotary valve and process plant with a rotary valve

Abstract

The invention relates to a rotary valve (1) for dosing, introducing and / or discharging granules and to a process plant (2) for pulsation-free dosing, introducing and / or discharging granules, comprising a granulator (3) and a rotary valve (1) connected to a discharge of the granulator (3).

Description

[0001]Cell wheel lock and process plant with a cell wheel lock The invention relates to a cell wheel lock for dosing, introducing and / or discharging granulate, with a housing in which an interior space is formed which is delimited by a housing wall with a cylindrical inner wall surface and has a central central axis, wherein the housing has, in an introduction zone, an introduction unit with an inlet opening opening into the interior space and, in a discharge zone spaced apart in the circumferential direction of the central axis, a discharge unit with an outlet opening also opening into the interior space, with a cell wheel arranged in the interior space and rotatable about an axis of rotation coinciding with the central axis while executing a conveying rotational movement, which cell wheel has cell wheel vanes extending radially from the central axis towards the inner wall surface, wherein a cell wheel chamber is arranged between each two consecutive cell wheel vanesdesigned to receive granules, which move from the feed zone to the discharge zone during the conveying rotation. Furthermore, the invention relates to a processing plant for the pulsation-free dosing, introduction, and / or discharge of granules, comprising a granulator and a rotary valve connected to a discharge of the granulator. 2 In tablet production, in particular in the continuous production of solid dosage forms, also referred to as solids, rotary valves are used for the process step of dosing, introduction, and / or discharge of granules. WO 2020 / 156750 A1 discloses a rotary valve of this type. The rotary valve has a housing having at least one feed unit and at least one discharge unit, in which a rotationally driven rotary valve is arranged, which has a plurality of cell walls that extend substantially radially and the cellsof the cellular wheel in the circumferential direction, and wherein at least the cell walls of the cellular wheel are formed from an elastically flexible material and two adjacent cell walls are connected to each other in the region of their radially inner ends by means of a cell base, so that the cell bases of the cellular wheel are formed by elastically flexible membranes, which are each connected to two adjacent cell walls in the region of the radially inner ends thereof and each overlap a cavity arranged radially inside a respective membrane. DE 102004 044 217 B4 also discloses a cellular wheel lock. The cellular wheel lock has a housing which has an interior space delimited by a substantially cylindrical inner wall, an upper inlet opening into the interior space, a lower outlet opening out of the interior space, a central axis, and end faces delimiting the interior space, with the end facesclosing housing covers, which are attached to the housing and which have bearing openings concentric to the central axis, with a cellular wheel which is arranged concentrically to the central axis, which is rotatably mounted passing through the three bearing openings, and which has vanes which extend radially to the central axis up to the vicinity of the inner wall and in the direction of the central axis up to the vicinity of the housing covers, wherein each housing cover has at least one groove-like recess which is open to the interior and extends from the area of ​​the respective bearing opening radially to the central axis beyond the vanes into the outlet. A disadvantage of the cellular wheel locks known from the prior art is that they are not suitable for taking over further necessary process steps in tablet production. The object of the invention is therefore to provide a cellular wheel lock which overcomes the disadvantages of the prior art and is suitableIn addition to the dosing, introduction, and discharge of granules, further process steps for tablet production can be carried out. This task is achieved in a rotary valve of the type mentioned above in that the housing wall extends over the outlet opening and has a sieve wall section in the area of ​​the outlet opening. The sieve enables further processing of the granules by crushing and sieving the granules. Advantageously, the rotary valve thus also carries out the process steps of sieving and crushing the granules in addition to the dosing, introduction, and discharge of granules. Furthermore, sieving and crushing the granules enables an improvement in the dosing of small mass flows in particular through the rotary valve. 4 The sieve can be designed in a wide variety of different configurations. For example, as a wire sieve design or as aMetal insert, expediently as a sheet metal or steel insert. According to an advantageous design of the rotary valve in this regard, the screen is removable and / or replaceable. By replacing the screen, it is possible to insert screens with different mesh sizes into the rotary valve and thus adapt the particle size of the granulate to the process requirements. The screen can also be replaced if it becomes worn. In addition, the possibility of removing the screen also ensures easy cleaning of the screen. If no screen is required, the screen can be omitted or, for example, a simple frame can be used. According to a further development of the rotary valve, the inner wall surface is at least partially designed as a sealing surface and / or each rotary wheel vane has a vane surface that is at least partially designed as a sealing surface. The design of the sealing surfaces can compensate for pressure differences betweenThe input side and the discharge side are effectively separated from each other. According to an additional development of the rotary valve, the rotary valve has a drive unit that sets the rotary valve in the conveying rotary motion. The drive unit is expediently suitable for carrying out a uniform conveying rotary motion or an alternating conveying rotary motion. In this case, the alternating conveying rotary motion comprises a rotation of the rotary valve in the conveying direction (forward movement) and a subsequent rotation of the rotary valve against the conveying direction (backward movement), whereby the rotation of the rotary valve in the conveying direction is greater than the rotation of the rotary valve against the conveying direction. At the same time, the conveying rotary motion should always be viewed in relation to a screen length. Preferably, the rotation of the rotary valve in the conveying direction takes place by an angle θ and the subsequent rotation of the rotary valve against the conveying directionthe conveying direction by an angle ^, wherein the angle ^ is greater than the angle ^. This improves the screening and comminution process of the granules and ensures improved emptying of the cell wheel chamber. Preferably, the angle ^ has an angular dimension between 5° and 30° and the angle ^ an angular dimension between 5° and 25°, wherein expediently the angle ^ has an angular dimension of 10° and the angle ^ an angular dimension of 5°. Furthermore, the cell wheel blades are designed such that the cell wheel chambers span a multi-flight helical space. Due to the multi-flight helical spaces of the cell wheel chambers, a uniform mass flow is achieved through the adequate superposition of the cell wheel chambers above the screen, thus improving the metering of the granules through the cell wheel lock. The wider the cellular wheel is, the more advantageous a multi-turn helical space in the cellular wheel chamber is for a uniformMass flow. Preferably, the feed zone and the discharge zone are arranged asymmetrically to one another in the housing. The asymmetrical arrangement of the feed zone and discharge zone to one another achieves optimal filling of the cell chambers, which preferably have a multi-threaded helical arrangement. 6 According to a further development of the rotary valve, the rotary chambers have an asymmetrically designed cross-sectional area. The asymmetrically designed cross-sectional area of ​​the rotary chamber has a positive effect on optimal filling of the rotary chamber on the feed side and a positive effect on the emptying of the rotary chamber on the discharge side. According to an additional development of the rotary valve, the rotary wheel has at least one nozzle arrangement for compressed air-controlled emptying of each rotary chamber. The nozzle arrangement improves the emptying of the rotary chamber. In this regard, theNozzle arrangement designed to enable angle-controlled injection of compressed air in the area of ​​the screen wall section. This object is further achieved in a system of the type mentioned above in that the rotary valve is designed as a rotary valve according to one of claims 1 to 13. Such a processing plant is advantageously suitable for producing the granules required in tablet production, in particular in the continuous production of solid dosage forms, and for dosing them according to the process requirements for further processing in the process. According to an advantageous embodiment in this regard, the granulator is designed as a fluidization apparatus, expediently as a fluidized bed or spouted bed apparatus. The invention is explained in more detail below with reference to the accompanying drawing, which shows: Figure 1 shows a processing plant with a rotary valve connected downstream of a granulator, Figure 2 shows a processing plant with a rotary valve connected downstream of a granulator,Figure 2 shows a plan view of a first embodiment of the rotary valve with a section plane AA. Figure 3 shows a section of the first embodiment of the rotary valve shown in Figure 1 through the section plane AA. Figure 4 shows a radial view of a rotary valve arranged in the first embodiment of the rotary valve. Figure 5 shows a plan view of the rotary valve with a section plane BB. Figure 6 shows a half-section of the second embodiment of the rotary valve shown in Figure 5 through the section plane BB. Figure 7 shows a radial view of a rotary valve arranged in the second embodiment of the rotary valve. Unless otherwise stated, the following description refers to all embodiments of a rotary valve 1 for dosing, introducing, and / or discharging granules and a process plant 2 comprising the rotary valve 1 illustrated in the drawing. The process plant 2has the rotary valve 1 downstream of a granulator 3. The granulator 3 is designed as a shear granulator 4, as a roller compactor 8, or as a fluidization apparatus, particularly as a fluidized bed or spouted bed apparatus. The rotary valve 1 is arranged upstream of a dryer 5, in particular a fluidized bed dryer 6, and is connected to it by means of a line 7, expediently a flexible hose connection 59. The process plant 2 having the rotary valve 1 is suitable for ensuring pulsation-free metering, introduction, and / or discharge of granules into the dryer 5. The rotary valve 1 has a housing 9 having a housing wall 8 and an at least substantially cylindrical interior space 10, wherein the interior space 10 is delimited by a cylindrical inner wall surface 11. Furthermore, the interior 10 has a central axis 12. The interior 10 of the housing 9 isis open at its end faces 13, 14, wherein the end faces 13, 14 are each covered by a housing cover 15, 16 which is detachably fastened to the housing 9 by means of screws (not shown). An inlet unit 19 arranged in an inlet zone 17 and having an inlet opening 18 opens into the interior 10 from above. In a discharge zone 20 spaced apart in the circumferential direction from the central axis 12, there is arranged a discharge unit 22 which also opens into the interior 10 and has an outlet opening 21. The housing wall 8 extends over the outlet opening 21 and has a sieve wall section 24 designed as a sieve 23 in the region of the outlet opening 21. The sieve 23 is expediently removable and / or replaceable. In the first embodiment of the rotary valve 1 shown in Fig. 3, the screen 23 has holes 26 extending radially in the housing wall 8 and formed as bores 25. In 9 of the embodiment shown in Fig. 6In the second embodiment of the rotary valve 1, the holes 26 formed as bores 25 run axially to a longitudinal center axis 27 of the rotary valve 1. The sieve 23 can be designed in a wide variety of ways. For example, as a wire sieve design or as an insert made of metal, expediently as a sheet metal or steel insert. By replacing the sieve 23, it is possible to insert sieves 23 with different mesh sizes into the rotary valve 1 and thus adapt the particle size of the granulate to the process requirements. Typical mesh sizes are in the range between 0.1 mm and 2 mm, in particular between 1.0 mm and 1.5 mm. Furthermore, the bores 25 formed as holes 26 can expediently also be shaped differently. The bores 25 can, for example, be square, round, oval, parallelogram-shaped, or the like. In addition, the sieve 23 can also have holes 25 of differenthave a shape. The sieve 23 can also be replaced if it becomes worn. In addition, the ability to remove the sieve 23 ensures that it is easy to clean. If a sieve 23 is not required, the sieve 23 can be omitted or, for example, a simple frame (not shown) can be used. Advantageously, the rotary valve 1 thus takes over the process steps of sieving and comminuting 10 the granules in addition to dosing, introducing, and discharging them. Furthermore, sieving and comminuting the granules makes it possible to improve the dosing of small mass flows in particular through the rotary valve 1. In the first embodiment of the rotary valve 1 shown in Fig. 3, the inlet zone 17 is arranged on the upper half-side 28 of the rotary valve 1 and the outlet zone 20 is arranged on the lower half-side 29 of the rotary valve 1. The inner wall surfaces 30, 31 of theThe input unit 19 runs parallel to the longitudinal center axis 27, perpendicular from a top side 57 to a bottom side 58. The inner wall surface 32 of the discharge unit 22 runs obliquely to the longitudinal center axis 27 from the top side 57 to the bottom side 58 of the rotary valve 1, whereas the inner wall surface 33 runs parallel to the longitudinal center axis 27, perpendicular from the top side 57 to the bottom side 58. Thus, a discharge area 34 of the discharge unit 22 is smaller than a projected area 35 of the outlet opening 21. The input zone 17 and the discharge zone 20 are arranged at least partially offset from one another over a width 36 of the rotary valve 1. As a result, the input zone 17 and the discharge zone 20 are arranged asymmetrically to one another in the housing 9. In contrast, the input zone 17 and the discharge zone 20 are arranged vertically one above the other centrally in the rotary valve 1, as in the second embodiment of the rotary valve 1 in Fig. 6shown. The inner wall surfaces 30, 31 of the input unit 19 are conical, converging from the top side 57 to the bottom side 58 of the rotary valve 1. The input surface 37 of the input unit 19 is thus larger than a projected area 38 of the inlet opening 18. The inner wall surfaces 32, 33 of the discharge unit 22 are conical, diverging from the top side 57 to the bottom side 58 of the rotary valve 1. Thus, a discharge surface 34 of the discharge unit 22 is larger than a projected area 35 of the outlet opening 21. The input unit 19 and the discharge unit 22, like the input zone 17 and the discharge zone 20 in the housing 9, are thus designed symmetrically to a mirror axis 39. In the interior space 10, a cellular wheel 42 is arranged, which rotates about a rotational axis 40 coinciding with the central axis 12, while executing a conveying rotational movement 41. The cellular wheel 42 is arranged in the interior space 10 in a replaceable manner.The shaft 46 of the cellular wheel 42, driven by a drive unit 43, expediently by a motor 44, preferably an electric or torque motor 45, passes through bearing openings (not shown) formed in the housing covers 15, 16 and is rotatably mounted in the bearings (not shown) mounted in the housing covers 15, 16. Furthermore, the cellular wheel 42 has cellular wheel vanes 47 extending radially from the central axis 12 toward the inner wall surface 11. Between each two consecutive cellular wheel vanes 47, a cellular wheel chamber 48 is formed for receiving granulate. The cellular wheel 42 has a plurality of cellular wheel chambers 48, preferably between 3 and 25 cellular wheel chambers 48. The cellular wheel chamber 48 moves in the conveying direction 49 from the input zone 17 to the discharge zone 20. Due to the asymmetrical arrangement of the input zone 17 and discharge zone 20 to each other, an optimal filling of the cellular chambers 48 is achieved. EachCell wheel chamber 48 receives granules below the feed unit 19, and at the discharge unit 22, the granules are conveyed through the screen wall section 24 designed as a sieve 23. This results in a volumetrically continuous conveyance of the granules at, expediently, 1 to 100 rpm of the cell wheel 42. The conveying capacity is determined by the granule content of the cell wheel chambers 48 and the speed of the cell wheel 42. As shown in Figs. 2 and 4, the cell wheel vanes 47 of the first embodiment of the cell wheel 42 are designed such that the cell wheel chambers 48 span a multi-threaded helical space 50 in the axial direction of the rotation axis 40. Due to the multi-threaded helical spaces 50 of the rotary chambers 48, a uniform mass flow is achieved by adequate superposition of the rotary chambers 48 above the screen 23, thus improving the dosing of the granules through the rotary valve 1. Advantageously, the space 50 has an asymmetricalformed cross-sectional area 51. The wider the cellular wheel 42 is, the more advantageous a multi-thread helical space 50 of the cellular wheel chamber 48 is for a uniform mass flow. In contrast to the first embodiment of the cellular wheel 42, the cellular wheel vanes 47 of the second embodiment of the cellular wheel 42 shown in Fig. 7 are designed such that the space 50 formed between two successive cellular wheel vanes 47 takes on the shape of a half cylinder. The cross-sectional area 51 of the cellular wheel chambers 48 is thus semicircular, as shown in Fig. 6. The drive unit 43 is expediently configured to effect a constant conveying rotational movement 41 of the cellular wheel 42. Such a conveying rotational movement 41 is realized in the first embodiment. The arrangement of the cellular wheel chambers 48 with a constant conveying rotary movement 41 is expediently selected so that at any time theDuring the conveying rotational movement 41, at least two cell wheel chambers 48 are at least partially in contact with the screen 23. This can suppress pulsation of the mass flow. Alternatively, the drive unit 43 is suitable for effecting a conveying rotational movement 41, which is expediently designed as an alternating conveying rotational movement 41. Such a conveying rotational movement 41 is implemented in the second embodiment. Here, the alternating conveying rotational movement 41 comprises a rotation of the cell wheel 42 in the conveying direction 49 (forward movement) and a subsequent rotation of the cell wheel 42 counter to the conveying direction 49 (backward movement). During the alternating conveying rotational movement 41, the rotation of the cell wheel 42 in the conveying direction 49 (forward movement) is preferably greater than the rotation of the cell wheel 42 counter to the conveying direction 49 (backward movement). At the same time, the conveyor rotation 41 should always be in relation to a screen length 60can be seen. Even with the alternating conveying rotation 41, the arrangement of the cellular wheel chambers 48 is expediently selected such that at any time during the conveying rotation 41, at least two cellular wheel chambers 48 are at least partially in contact with the screen 23. This can suppress pulsation of the mass flow. For example, with an alternating conveying rotation 41 and a screen length 60 of 60 mm, the forward movement can also be 60 mm and the backward movement 45 mm. Other values ​​for the forward and / or backward movement are also feasible. Thus, after one cycle, i.e., one forward and one backward movement, the cellular wheel 42 14 undergoes a "net" rotation of 15 mm in the conveying direction 49. This prevents the same screen surface 61 from always being used and the same screen surface 61 from always being cleaned by the backward movement. This naturally results in angles, namely an angle αfor the forward movement and an angle β for the backward movement. Accordingly, the alternating conveying rotation 41 also means in particular the rotation of the cell wheel 42 in the conveying direction 49 by an angle α and subsequent rotation of the cell wheel 42 against the conveying direction 49 by an angle β, wherein the angle α is greater than the angle β. This improves the screening and comminution process of the granulate and ensures improved emptying of the cell wheel chamber 48. Preferably, the angle α has an angular dimension between 5° and 30° and the angle β has an angular dimension between 5° and 25°, wherein particularly preferably the angle α has an angular dimension of 10° and the angle β has an angular dimension of 5°. The angles α and β are preferably selected so that at any time during the conveying rotational movement 41 at least two spaces 50 are at least partially in contact with the screen 23. This can prevent pulsation of theMass flow can be suppressed. The rotary conveying movement 41 can be determined by the selection of the drive unit 43; in particular, a constant rotary conveying movement 41 or an alternating rotary conveying movement can be selected. The drive unit can also be designed to effect, on the one hand, the constant rotary conveying movement 41 of the cellular wheel 42 and, on the other hand, the alternating rotary conveying movement 41. 15 The formation of sealing surfaces 52, 53 makes it possible to effectively separate pressure differences occurring between the feed unit 19 and the discharge unit 22 and, accordingly, to maintain two different pressure levels. By way of example, in the first embodiment of the rotary valve 1 shown in Fig. 3, the inner wall surface 11 is at least partially designed as a sealing surface 52 and each rotary vane 47 has a sealing surface 53 which is at least partially designed as a sealing surface.Vane surface 54. 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. In the second embodiment of the rotary valve 1 shown in Fig. 6, two different possibilities are shown by way of example, comprising a nozzle arrangement 55 for the compressed air-controlled emptying of the rotary valve chambers 48. In the first example, the rotary valve 42 has the nozzle arrangement 55 for emptying each rotary valve chamber 48 in the form of a plurality of nozzles 56 arranged in the rotary valve vane 47. In a second example, the housing cover 15 has the nozzle arrangement 55, in particular in the form of nozzles 56 for emptying each rotary valve chamber 48. The nozzle arrangement 55 is particularly preferably designed to enable angle-controlled injection of compressed air in the region of the screen wall section 24. It is particularly preferred if the housing cover 15,16 forEach cellular wheel chamber 48 arranged simultaneously above the screen wall section 24 has nozzles 56 arranged therein. If, for example, two cellular wheel chambers 16 48 are arranged simultaneously above the screen 23, compressed air should be able to be blown into both of them via nozzles 56.

Claims

17 Claims 1. Rotary valve (1) for metering, feeding and / or discharging granules, comprising a housing (9) in which an interior space (10) is formed, bounded by a housing wall (8) with a cylindrical inner wall surface (11) and having a central axis (12), wherein the housing (9) has in a feeding zone (17) a feeding unit (19) opening into the interior space (10) with an inlet opening (18) and in a discharge zone (20) spaced in this respect circumferential direction of the central axis (12) a discharge unit (22) also opening into the interior space (10) with an outlet opening (21), comprising a rotary valve (42) arranged in the interior space (10) and rotatable about an axis of rotation (40) coinciding with the central axis (12) in the form of a conveying rotary motion (41), which extends radially has rotary vanes (47) extending from the central axis (12) to the inner wall surface (11),wherein a rotary chamber (48) for receiving granules is formed between each pair of successive rotary rotor blades (47), which moves from the feed zone (17) to the discharge zone (20) during the conveying rotary movement (41), characterized in that the housing wall (8) extends over the discharge opening (21) and has a screen wall section (24) designed as a screen (23) in the area of ​​the discharge opening (21). 18 2. Rotary valve (1) according to claim 1, characterized in that the screen (23) is removable and / or replaceable.

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

4. Rotary valve (1) according to any one of the preceding claims, characterized in that the rotary valve (1) has a drive unit (43) that sets the rotor (42) into the conveying rotary motion (41).

5. Rotary valve (1) according to claim 4, characterized in that the drive unit (43) is suitable for performing a uniform conveying rotary motion (41) or an alternating conveying rotary motion (41). 6.Rotary valve (1) according to claim 5, characterized in that the alternating conveying rotary motion (41) comprises a rotation of the rotary valve (42) in the conveying direction (49) and a subsequent rotation of the rotary valve (42) against the conveying direction (49), wherein the rotation of the rotary valve (42) in the conveying direction (49) is greater than the rotation of the rotary valve (42) against the conveying direction (49). Rotary valve (1) according to claim 6, characterized in that the rotation of the rotary valve (42) in the conveying direction (49) is by an angle α and the subsequent rotation of the rotary valve (42) against the conveying direction (49) is by an angle β, wherein the angle α is greater than the angle β. 19 8. Rotary valve (1) according to claim 7, characterized in that the angle α has an angular dimension between 5° and 30° and the angle β has an angular dimension between 5° and 25°, wherein, advantageously, the angle α has an angular dimension of 10° and the angle β has an angular dimension of 5°.

9. Rotary valve (1) according to any one of the preceding claims, characterized in that the rotor vanes (47) are configured such that the rotor chambers (48) form a multi-turn helical space (50).

10. Rotary valve (1) according to any one of the preceding claims, characterized in that the inlet zone (17) and the outlet zone (20) are arranged asymmetrically to each other in the housing (9).

11. Rotary valve (1) according to one of the preceding claims, characterized in that the rotary valve chambers (48) have an asymmetrically shaped cross-sectional area (51). 12.Rotary valve (1) according to one of the preceding claims, characterized in that the rotary valve (1) has at least one nozzle arrangement (55) for compressed air-controlled emptying of the rotary valve chambers (48).

13. Rotary valve (1) according to claim 12, characterized in that the rotary valve (42) has the nozzle arrangement (55) for emptying each rotary valve chamber (48) and / or a housing cover (15, 16) has the nozzle arrangement (55) for emptying each rotary valve chamber (48). 20 14. Process plant (2) for pulsation-free dosing, feeding and / or discharging of granules, comprising a granulator (3) and a rotary valve (1) connected to a discharge of the granulator (3), characterized in that the rotary valve (1) is configured as a rotary valve (1) according to any one of claims 1 to 13.

15. Process plant according to claim 14, characterized in that the granulator (3) is configured as a fluidization apparatus, expediently as a fluidized bed or jet bed apparatus.

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