Abstract
A powder blender for a system for continuous processing of powder products comprises a horizontal blending tube extending along an axis from a first end to a second end. The horizontal blending tube comprises at least one inlet configured to receive the powder products to be blended, and at least one outlet configured to discharge the powder products after blending. At least two blending devices are positioned in the blending tube and arranged successively along the axis of the blending tube. At least two actuators, wherein each of the at least two actuators is configured to operate one of the at least two blending devices such that the at least two blending devices are actuated differently from each other.
Claims
1. A powder blender for a system for continuous processing of powder products comprising: a horizontal blending tube extending along an axis from a first end to a second end and comprising, at least one inlet configured to receive the powder products to be blended, and at least one outlet configured to discharge the powder products after blending; at least two blending devices positioned in the blending tube and arranged successively along the axis of the blending tube; and at least two actuators, wherein each of the at least two actuators is configured to operate one of the at least two blending devices such that the at least two blending devices are actuated differently from each other.
2. The powder blender according to claim 1, wherein the at least two blending devices each comprise a blending shaft extending along a longitudinal axis and configured to be rotated about the longitudinal axis by one of the at least two actuators.
3. The powder blender according to claim 2, wherein each of the at least two blending shafts comprises a plurality of blending blades configured to blend the powder products.
4. The powder blender according to claim 3, wherein each of the at least two blending shafts differ from each other in at least one of: (1) shape; (2) orientation; and (3) position of the blending blades.
5. The powder blender according to claim 4, wherein at least some of the blending blades are adaptable with regard to at least one of: (1) shape; (2) orientation; and (3) position.
6. The powder blender according to claim 2, wherein one end of a first blending shaft faces one end of a second blending shaft, and wherein the one ends of the first blending shaft and the second blending shaft are supported on each other.
7. The powder blender according to claim 1, wherein the at least two actuators are configured to actuate at least one of: (1) rotational speed; and (2) rotational direction of the at least two blending shafts differently from one another.
8. The powder blender according to claim 2, wherein at least one of the blending shafts is configured to be removed and replaced with a different blending shaft.
9. The powder blender according to claim 1, further comprising an overflow device positioned in the blending tube, wherein one of the at least two blending devices is arranged upstream of another of the at least two blending devices, and wherein the overflow device is positioned between the at least two blending devices and configured for powder product to flow over the overflow device.
10. The powder blender according to claim 9, wherein the overflow device comprises at least one overflow plate configured to rotate, and wherein the mass of powder product flowing over the overflow device is adjusted by rotating the at least one overflow plate.
11. The powder blender according to claim 1, wherein at least one of: (1) the at least one inlet is positioned on an upper side of the blending tube; (2) and the at least one outlet is positioned at the lower side of the blending tube.
12. The powder blender according to claim 1, wherein the blending tube comprises at least two inlets, wherein at least one of the at least two inlets is positioned above a first blending device, and wherein one of the at least two inlets is positioned above a second blending device.
13. The powder blender according to claim 1, wherein the blending tube comprises a length and a diameter, and wherein a ratio of a size of the length relative to a size of the diameter is at least 5:1.
14. The powder blender according to claim 13, wherein the ratio is at least 7:1.
15. The powder blender according to claim 1, further comprising at least one sensor configured to measure a mass of powder product in the blending tube.
16. The powder blender according to claim 1, further comprising a blender support configured to support the powder blender, wherein the powder blender is balanced without powder product present in the blending tube.
17. The powder blender according to claim 1, wherein the at least two blending devices are actuated independent from each other.
17. A feeding and blending apparatus for a system for processing of powder products, the feeding and blending apparatus comprising: at least two apparatus inlets configured to accept powder products into the feeding and blending apparatus; at least one powder blender according to claim 1; and at least two feeding and dosing devices, each comprising, an inlet connected with one of the at least two apparatus inlets, and an outlet being connected to at least one inlet of the powder blender.
19. A system for processing of powder products comprising: a feeding and blending apparatus according to claim 18; and a production machine comprising an inlet connected with the at least one outlet of the powder blender and an outlet.
Description
BRIEF DESCRIPTION OF THE DRAWINGS
[0042] Embodiments of the invention are explained in more detail below with reference to the drawings. The drawings schematically show:
[0043] FIG. 1 illustrates a side view of an embodiment of a system for continuous processing powder products;
[0044] FIG. 2 illustrates a perspective view of an embodiment of a feeding and blending system of the system shown in FIG. 1;
[0045] FIG. 3 illustrates another perspective view of an embodiment of the feeding and blending system of the system shown in FIG. 1;
[0046] FIG. 4 illustrates a perspective view of an embodiment of a powder blender of the feeding and blending system shown in FIGS. 2 and 3;
[0047] FIG. 5 illustrates a perspective view of the embodiment of the powder blender of FIG. 4 with the housing partially removed;
[0048] FIG. 6 illustrates a sectional view of the embodiment of the powder blender shown in FIG. 4; and
[0049] FIG. 7 illustrates a perspective view of another embodiment of a powder blender with the housing partially removed.
[0050] In the drawings the same reference numerals shall denote the same parts.
DETAILED DESCRIPTION OF THE INVENTION
[0051] The system for continuous processing of powder products shown in FIG. 1 is a system for continuous production of solid dosage forms in direct processing. The system comprises a feeding and blending system 10 and a production machine 12, for example a tablet press, such as a rotary tablet press, or a capsule filling machine. The production machine 12 comprises an inlet 14 which is connected with a hose 16 of a product conveying device conveying a product mixture from the feeding and blending system 10 to the inlet 14 of the production machine 12, where the product mixture is continuously processed to solid dosage forms, such as tablets or capsules. The produced solid dosage forms are discharged via an outlet 18 of the production machine 12. The production machine 12 comprises a machine housing 20 with a window 22. The feeding and blending system 10 comprises a system housing 24 with two doors 26, which are opened in FIG. 2 to view the internal parts of the feeding and blending system 10. The system shown in FIG. 1 is a one-floor arrangement where the feeding and blending system 10 and the production machine 12 are provided on the same level, in particular the same floor level.
[0052] In FIGS. 2 and 3, six (6) system inlets 28 can be seen via which different powder products can be introduced into the feeding and blending system 10. The system inlets 28 lead to six (6) automatic refill systems, each comprising a horizontal refill screw 30. As can be seen in FIGS. 2 and 3, feeding and dosing devices, in particular feeders 32, are arranged in a row, in particular along a horizontal line. The feeding and dosing devices, in particular the feeders 32, each comprise an inlet 34 arranged between the refill screws 30 and the feeders 32. The feeding and dosing devices, in particular the feeders 32, further each comprise an outlet 36 for feeding a powder product supplied via the inlets 28 and the refill units 30 to a powder blender 38. The powder blender 38 comprises a horizontal blending tube 39 for blending the different powder products to the desired product mixture. In the example shown in the drawings, a funnel or hopper 40 is arranged between the feeders 32 and the powder blender 38, said funnel or hopper 40 combining product streams from four of the six feeders 32 into one product stream and into a first inlet 42 of the powder blender 38. The funnel or hopper 40 may be provided with a vibration device 41 for promoting powder flow in the funnel or hopper 40. The powder blender 38 comprises further inlets 44 through which powder streams from further feeders 32 can be introduced into the powder blender 38 for example via vertical tubes 74. A venting pipe 45 is provided on the end opposite inlet 42 of the powder blender 38 for venting air into the environment. A similar venting pipe 47 is provided at the top of the funnel or hopper 40. The powder blender 38 further comprises an outlet 46 through which the produced product mixture is provided to a blender outlet hopper 48, from which the product mixture is conveyed via hose 16 to the inlet 14 of the production machine 12 for further processing. The blender outlet hopper 48 can be used in mini-batch blending processes.
[0053] A separation wall 50 is provided inside system housing 24 separating a process area, seen in FIG. 2, and seen in FIG. 3 on the left-hand side, from a technical area, positioned behind separation wall 50 in FIG. 2, and seen in FIG. 3 on the right-hand side. This separation wall 50 may provide a contained or dust tight separation between the process area and the technical area. In the process area process components of the automatic refill systems, the feeding and dosing devices and the powder blender are arranged which come into direct contact with the powder products to be processed. In the technical area, technical components of the automatic refill systems, the feeding and dosing devices, and the powder blender are arranged which do not come into direct contact with the powder products. In the case at hand these technical components comprise actuators 52 for actuating the refill screws 30, in the example shown drives 52 for driving the refill screws 30, actuators 54 for actuating the feeders 32, in the example shown drives 54 for driving the feeders 32, and a first actuator 56 and a second actuator 58 for actuating the powder blender 38, in the example shown a first drive 56 and a second drive 58 for driving the powder blender 38. The drives 52, 54, 56, 58 may comprise for example electric motors. The connection between the technical components, such as the drives 52, 54, 56 and 58, and the process components, such as the refill screws 30, the feeders 32, and the powder blender 38, are arranged in a through the wall technique through the separation wall 50. For easier installation and maintenance these connections may be quick release connections. While the system housing 24 provides a protective housing 24 the separation wall 50 securely separates the process area, in which the powder products are handled, from the technical area, where no powder products shall be present. In this manner on the one hand an intrinsic containment can be achieved of the process area in comparison to the technical area, and on the other hand a containment towards the environment can be achieved through the protective housing 24. Also, the housing 20 of the production machine 12 may provide containment towards the environment, as generally explained above.
[0054] From FIGS. 4 to 6 it can be seen that in the horizontal blending tube 39 of powder blender 38 a first blending shaft 60 with blending blades 62, and a second blending shaft 64, also with blending blades 66, are arranged. The blending shafts 60, 64 are arranged coaxially successively along the longitudinal axis of the blending tube 39 of the powder blender 38, which in FIG. 5 runs horizontally. In the case at hand the first and second blending shafts 60, 64 define two successive blending zones along the longitudinal axis of the blending tube 39 of the powder blender 38, wherein in the example shown the blending zones have approximately the same length. Of course the lengths could also be different. The first drive 56 serves to rotate the first blending shaft 60 about its longitudinal axis, and the second drive 58 serves to rotate the second blending shaft 64 about its longitudinal axis. The drives 56, 58 are designed to drive the first and second blending shafts 60, 64 independently from one another. In particular, it is possible to drive the first and second blending shafts 60, 64 with different rotational speed and/or different rotational direction. In the case at hand powder products introduced into the blending tube 39 of the powder blender 38 are conveyed through the blending tube 39 first through the first blending zone, defined by the first blending shaft 60, and subsequently through the second blending zone defined by the second blending shaft 64, in FIG. 6 thus from right to left. After having been conveyed through the blending tube 39 the blended powder mixture is discharged via outlet 46.
[0055] The ability to control rotation of the blending shafts 60, 64 independently from one another allows for a flexible adaptation to the process, in particular the powder products to be processed, and optimises the blending result, such as blend uniformity. One or both of the blending shafts 60, 64 may be provided with a quick release connection to be easily removable and replaceable with a different blending shaft which may have a different geometry of blending blades, thus allowing to adapt the powder blender 38 easily for different blending processes.
[0056] The powder blender 38 may further be provided with a load cell measuring the mass of powder product in the blending tube 39. A control unit of the inventive system, integrated for example into the production machine 12, can control the drives 56, 58, and thus the blending shafts 60, 64 on basis of measurement results of the load cell sensor. As can be seen specifically in FIG. 3 the powder blender 38 with blending tube 39 is supported via a blender frame 68 on a support plate 70. The support location can be seen at reference numeral 72 for the connection between drive 56 and the first blending shaft 60, wherein a corresponding support location is present between drive 58 and second blending shaft 64, not seen in FIG. 3. The support via the blender frame 68 on the support plate 70 is such that a load cell sensor measures no or only a small load when the blending tube is empty, i.e. no powder product is present in the blending tube. In FIG. 3, the mass of the powder blender 38 including the drives 56, 58, the frame 68 and the respective connections is essentially the same on both sides of the support locations 72, in FIG. 3 right and left of the support locations 72. This arrangement allows using a more sensitive load cell sensor, thus providing higher measurement accuracy. A load cell sensor can for example be provided on or underneath the blending tube 39 or on or underneath the blender frame 70.
[0057] FIG. 7 shows a further embodiment of a powder blender 38′ of an inventive feeding and blending system. The powder blender 38′ shown in FIG. 7 corresponds largely to the powder blender 38 shown in FIGS. 4 to 6. It can be used in the same manner in the inventive feeding and blending system 10 shown in FIGS. 2 and 3 and the inventive system for continuous processing powder products shown in FIG. 1 as the powder blender 38 shown in FIGS. 4 to 6.
[0058] The powder blender 38′ shown in FIG. 7 merely differs from the powder blender 38 shown in FIGS. 4 to 6 in having an adjustable overflow device arranged in the blending tube 39 between the first and second blending devices for allowing an adjustable mass of powder product to flow over the overflow device. The overflow device in the example shown in FIG. 7 comprises two rotatable overflow plates 76, 78, both in the shape of a half circle. By rotating at least one of the overflow plates 76, 78 the mass of powder product flowing over the overflow plates 76, 78 can be adjusted. For example, when the rotational position of the overflow plates 76, 78 is such that the two half circles form a full circle, like shown in FIG. 7, the flow of powder product over the overflow plates 76, 78 can be fully shut off. By rotating at least one overflow plate 76,78 out of the full circle, an adjustable amount of powder product can pass the overflow plates 76, 78.
LIST OF REFERENCE NUMERALS
[0059] 10 feeding and blending system [0060] 12 production machine [0061] 14 inlet of the production machine [0062] 16 hose [0063] 18 outlet of the production machine [0064] 20 machine housing [0065] 22 window [0066] 24 system housing [0067] 26 doors [0068] 28 system inlets [0069] 30 refill screws [0070] 32 feeders [0071] 34 inlets of feeders [0072] 36 outlet of feeders [0073] 38, 38′ powder blender [0074] 39 blending tube [0075] 40 funnel or hopper [0076] 42, 44 inlets of powder blender [0077] 46 outlet of powder blender [0078] 45, 47 venting pipes [0079] 48 blender outlet hopper [0080] 50 separation wall [0081] 52 actuators/drives for refill screws [0082] 54 actuators/drives for feeders [0083] 56 first actuator/drive for powder blender [0084] 58 second actuator/drive for powder blender [0085] 60 first blending shaft [0086] 62 blending blades of first blending shaft [0087] 64 second blending shaft [0088] 66 blending blades of second blending shaft [0089] 68 blender frame [0090] 70 support plate [0091] 72 support location [0092] 74 vertical tubes [0093] 76, 78 overflow plates
