DISCHARGE APPARATUS FOR DISCHARGING PELLETS FROM A ROTARY PRESS

Abstract

A discharge apparatus for discharging pellets from a rotary press comprises an inlet channel configured to receive pellets from an ejection apparatus of the rotary press, a first discharge channel connected to the inlet channel, and a second discharge channel connected to the inlet channel. A gate is positioned between the inlet channel and the first and second discharge channels. The gate is configured to be shifted between a first position, in which pellets are directed from the inlet channel into the first discharge channel, and a second position, in which pellets are directed from the inlet channel into the second discharge channel. A pressure equalization channel configured to open into one of the first and second discharge channels and is configured to equalize a pressure between the inlet channel and at least one of the first and second discharge channels.

Claims

1. A discharge apparatus for discharging pellets from a rotary press, the discharge apparatus comprising: an inlet channel configured to receive pellets from an ejection apparatus of the rotary press; a first discharge channel connected to the inlet channel; a second discharge channel connected to the inlet channel; a gate positioned between the inlet channel and the first and second discharge channels, wherein the gate is configured to be shifted between a first position, in which pellets are directed from the inlet channel into the first discharge channel, and a second position, in which pellets are directed from the inlet channel into the second discharge channel; and a pressure equalization channel configured to open into one of the first and second discharge channels, wherein the pressure equalization channel is configured to equalize a pressure between the inlet channel and at least one of the first and second discharge channels.

2. The discharge apparatus according to claim 1, wherein a flow cross-section of the pressure equalization channel is at least 10% of a flow cross-section of the inlet channel.

3. The discharge apparatus according to claim 1, wherein a flow cross-section of the pressure equalization channel is at least 100% of a flow cross-section of the inlet channel.

4. The discharge apparatus according to claim 1, wherein the gate comprises a gate element configured to be pivoted between the first position and the second position.

5. The discharge apparatus according to claim 4, wherein the gate element is a gate leaf.

6. The discharge apparatus according to claim 4, wherein the gate element forms a portion of a wall of at least one of: (1) the inlet channel; (2) the first discharge channel; and (3) the second discharge channel.

7. The discharge apparatus according to claim 1, wherein the pressure equalization channel is directly connected to the inlet channel.

8. The discharge apparatus according to claim 1, wherein the pressure equalization channel is configured to be connected to the inlet channel via one or more interior spaces of the rotary press.

9. A rotary press comprising: a rotor comprising an upper punch guide and a lower punch guide; upper press punches configured to be guided by the upper punch guide; lower punches configured to be guided by the lower punch guide; a die plate positioned between the upper and lower punch guides and defining a plurality of openings, wherein the upper press punches and the lower press punches cooperate with the plurality of openings of the die plate; at least one filling apparatus configured to dispense filling material into the plurality of openings; at least one pressing apparatus configured to cooperate with the upper press punches and lower press punches during operation to press the filling material in the plurality of openings into pellets; an ejection apparatus configured to eject the pellets from the plurality of openings; and a discharge apparatus configured to discharge the pellets from the rotary press, the discharge apparatus comprising, an inlet channel configured to receive pellets from the ejection apparatus, a first discharge channel connected to the inlet channel, a second discharge channel connected to the inlet channel, a gate positioned between the inlet channel and the first and second discharge channels, wherein the gate is configured to be shifted between a first position, in which pellets are directed from the inlet channel into the first discharge channel, and a second position, in which pellets are directed from the inlet channel into the second discharge channel, and a pressure equalization channel configured to equalize a pressure between the inlet channel and at least one of the first and second discharge channels.

10. The rotary press according to claim 9, wherein the pellets are removed from the plurality of openings and deposited onto the die plate by the lower punches before the pellets reach the ejection apparatus.

11. The rotary press according to claim 9, wherein the ejection apparatus comprises a scraping apparatus configured to scrape the pellets off the die plate and into the inlet channel of the discharge apparatus.

12. The rotary press according to claim 9, further comprising a housing configured to enclose the rotor and the discharge apparatus.

13. The rotary press according to claim 12, wherein an interior of the housing is at a pressure that is different than a pressure within the discharge apparatus.

14. The rotary press according to claim 13, wherein the housing is sealed from an external environment.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Exemplary embodiments of the invention are explained in greater detail below based on figures, in which:

[0024] FIG. 1 illustrates a partial schematic depiction of an embodiment of a rotary press;

[0025] FIG. 2 illustrates an enlarged schematic depiction of an embodiment of a discharge apparatus of the rotary press of FIG. 1 in a first operating position;

[0026] FIG. 3 illustrates a schematic depiction of the embodiment of the discharge apparatus from FIG. 2 in a second operating position;

[0027] FIG. 4 illustrates a schematic depiction of another embodiment of a discharge apparatus of the rotary press shown in FIG. 1; and

[0028] FIG. 5 illustrates a schematic depiction of another embodiment of a discharge apparatus of the rotary press shown in FIG. 1.

[0029] The same reference numbers refer to the same objects in the figures unless indicated otherwise.

DETAILED DESCRIPTION OF THE INVENTION

[0030] The rotary press, in particular rotary tablet press, shown in FIG. 1 comprises a rotor that is rotationally driven by a rotary drive and that has a die plate 10 comprising a plurality of receiving means 12. The receiving means 12 may for example be in the form of holes in the die plate 10. Furthermore, the rotor comprises a plurality of upper punches 14 and lower punches 16 that rotate synchronously with the die plate 10. The upper punches 14 are axially guided in an upper punch guide 18 and the lower punches 16 are axially guided in a lower punch guide 20. The axial movement of the upper punches 14 and lower punches 16 during the rotation of the rotor is controlled by upper control cam elements 22 and lower control cam elements 24. The rotary press further comprises a filling apparatus 26, which comprises a filling reservoir 28 and a filling chamber 30, which are connected via a feed section 32. In this way, the powdered filling material in the present example passes under the force of gravity from the filling reservoir 28 via the feed section 32 into the filling chamber 30, and passes therefrom via a filling opening provided in the bottom side of the filling chamber 30 into the receiving means 12 of the die plate 10, again under the force of gravity.

[0031] The rotary press further comprises a pressing apparatus 34. The pressing apparatus 34 has a pre-pressing apparatus having an upper pre-pressing roller 36 and a lower pre-pressing roller 38, as well as a main pressing apparatus having an upper main pressing roller 40 and a lower main pressing roller 42. Furthermore, the rotary press comprises an ejection apparatus 44 and a scraping apparatus 46 of the ejection apparatus 44 having a scraping element, which feeds the pellets 48, in particular tablets, produced in the rotary press to a discharge apparatus 50 for discharging the pellets from the rotary press. The scraping apparatus 46 may for example comprise a preferably crescent-shaped scraping element 46, which scrapes pellets 48 conveyed by means of the lower punches 16 onto the top side of the die plate 10 off the die plate 10 in the region of the ejection apparatus 44 and feeds them to the discharge apparatus 50.

[0032] The rotary press also comprises a control apparatus 52 for controlling its operation. The control apparatus 52 is connected by lines (not shown) to, inter alia, the rotary drive of the rotor and controls the rotary press during operation. It may also be connected to any sensors of the rotary press, in particular receive any sensor data and use same as the basis for the control process. For the control process, the control apparatus 52 may be connected by corresponding lines to all components of the rotary press to be controlled.

[0033] Furthermore, the rotary press is arranged in a housing 53 shown as a dashed line in FIG. 1. In particular, the rotor and the discharge apparatus 50 of the rotary press are arranged in the housing 53. The housing 53 may be at a positive or negative pressure with respect to the surroundings of the housing 53 or with respect to the discharge channels 56, 58. Moreover, the housing 53 may be sealed with respect to the surroundings. The rotary press may be a so-called containment press.

[0034] The discharge apparatus 50 of the rotary press will now be explained in greater detail based on FIGS. 2 and 3. The discharge apparatus 50 comprises an inlet channel 54, to which pellets 48 scraped off the die plate 10 by means of the scraping apparatus 46 are generally fed. The discharge channel 50 additionally comprises a first discharge channel 56 and a second discharge channel 58. The first discharge channel 56 leads to a first outlet for pellets produced in the rotary press and the second discharge channel 58 leads to a second outlet for pellets produced in the rotary press. The first outlet, which is connected to the first discharge channel 56, may for example be an outlet for bad pellets, which were identified as flawed by a sensor system of the rotary press, for example. The second outlet, which is connected to the second discharge channel 58, may for example be an outlet for good pellets, which meet the predefined specifications. The discharge apparatus 50 also comprises an additional inlet channel 60, which is directly connected to the first discharge channel 56 and thus to the first outlet of the rotary press, for example for bad pellets. The scraping apparatus 46 may comprise a discarding apparatus, for example comprising a discarding nozzle, by means of which pellets identified as bad are discarded into the additional inlet channel 60 before they reach the inlet channel 54, such that they pass through the first discharge channel 56 and into the first outlet of the rotary press, for example for bad pellets. In principle, the discharge apparatus 50 may comprise a slope, such that the pellets conveyed into one of the inlet channels 54, 60 are conveyed through said apparatus by the force of gravity.

[0035] Furthermore, a gate 62 comprising a gate element 66 that can be pivoted about a pivot axis 64 between a first position shown in FIG. 2 and a second position shown in FIG. 3 is located between the inlet channel 54 and the first and second discharge channel 56, 58. The gate element 66 may for example be configured as a so-called gate leaf, for example in the form of a gate plate. In the first position, shown in FIG. 2, pellets conveyed into the inlet channel 54 are fed to the first discharge channel 56 and thus to the first outlet of the rotary press. However, in the second position, shown in FIG. 3, pellets are fed to the second discharge channel 58 and thus to the second outlet of the rotary press. The gate 62 comprises a corresponding pivot drive for moving the gate element 66 between the end positions shown in FIGS. 2 and 3. The gate element 66 thereby forms a portion of a wall of the inlet channel 54 and, depending on its position, of the first and/or second discharge channel 56, 58. Furthermore, a pressure equalization channel 68 that is permanently open in the example shown is arranged in parallel with the gate 62, by means of which channel the pressure is equalized between the inlet channel 54 on the one hand and the first and/or second discharge channel 56, 58 on the other. The pressure is also equalized between the additional inlet channel 60 and the first and/or second discharge channel 56, 58. In particular, the pressure equalization channel 68 is connected indirectly to the inlet channels 54, 60 via the rotor or press interior of the rotary press. However, the pressure equalization channel 68 is on the other hand connected directly to the second discharge channel 58. An airflow can take place by means of the pressure equalization channel 68, in particular when the gate element 66 is moved between the positions shown in FIGS. 2 and 3, which airflow reduces a pressure difference across the gate 62 at least to the extent that the gate element 66 safely and reliably reaches its relevant end position without larger drives being required.

[0036] In the example shown, the discharge apparatus 50 also comprises a third discharge channel 70, which leads to a third outlet of the rotary press for pellets, in particular an outlet for sampling, i.e. for pellets to be supplied for random testing. In the example shown, an additional gate 72, also comprising a gate element 76, again a gate leaf, for example, that can pivot about a pivot axis 74, is located between the second discharge channel 58 and the third discharge channel 70. This additional gate 72 is shown in both its positions/end positions in FIGS. 2 and 3. In this position, pellets directed into the second discharge channel 58 remain therein and arrive at the second outlet of the rotary press. By switching the second gate 72 into its second position, in which its free end adjoins the intermediate wall between the first and second discharge channel 56, 58, pellets directed into the second discharge channel 58 can be directed out of this channel and into the third discharge channel 70 and thus to the third outlet of the rotary press.

[0037] FIGS. 4 and 5 show other exemplary embodiments of a discharge apparatus according to the invention. In the exemplary embodiment according to FIG. 4, the pressure equalization channel 68 is directly connected to the inlet channel 54 on one side and directly connected to the first discharge channel 56 on the other side. It correspondingly ensures pressure equalization between the inlet channel 54 and the first discharge channel 56. In the exemplary embodiment shown in FIG. 5, the pressure equalization channel 68 is directly connected to the inlet channel 54 on one side and directly connected to the second discharge channel 58 on the other side. It correspondingly ensures pressure equalization between the inlet channel 54 and the second discharge channel 58. Otherwise, the discharge apparatuses according to FIGS. 4 and 5 can be designed or integrated into the rotary press in the same way as the exemplary embodiment according to FIGS. 1 to 3 explained above. For example, the discharge apparatuses according to FIGS. 4 and 5 may also comprise an additional gate 72 and a third discharge channel 70, as explained above with reference to FIGS. 1 to 3.

LIST OF REFERENCE SIGNS

[0038] 10 Die plate [0039] 12 Receiving means [0040] 14 Upper punches [0041] 16 Lower punches [0042] 18 Upper punch guide [0043] 20 Lower punch guide [0044] 22 Upper control cam elements [0045] 24 Lower control cam elements [0046] 26 Filling apparatus [0047] 28 Filling reservoir [0048] 30 Filling chamber [0049] 32 Feed section [0050] 34 Pressing apparatus [0051] 36 Upper pre-pressing roller [0052] 38 Lower pre-pressing roller [0053] 40 Upper main pressing roller [0054] 42 Lower main pressing roller [0055] 44 Ejection apparatus [0056] 46 Scraping apparatus [0057] 48 Pellets [0058] 50 Discharge apparatus [0059] 52 Control apparatus [0060] 53 Housing [0061] 54 Inlet channel [0062] 56 First discharge channel [0063] 58 Second discharge channel [0064] 60 Additional inlet channel [0065] 62 Gate [0066] 64 Pivot axis [0067] 66 Gate element [0068] 68 Pressure equalization channel [0069] 70 Third discharge channel [0070] 72 Additional gate [0071] 72 Pivot axis [0072] 76 Gate element