Feeder equipment for conveying powder materials

Abstract

A feeder device for feeding powder includes a cylindrical feed channel (3a) having a downstream end. The feed channel includes at least one conveying element for conveying powder material to the downstream end. A rotatable outlet element (9a, 9b) is disposed at the downstream end of the feed channel. The rotatable outlet element includes an annular portion defining an outlet opening defined by a powder-bonding edge. The rotatable outlet element is laterally positioned adjacent to the downstream end of the feed channel outside the cylindrical container (3a). The feed channel has a first inner diameter (d) and the rotatable outlet element (9a, 9b) has a second outer diameter (D), wherein the second outer diameter (D) is equal to or greater than the first inner diameter (d).

Description

[0001] This application is a divisional application of the application that entered the Chinese national phase on July 28, 2021, with application number 202080011348.4.

[0002] The present invention relates to a feeder device for feeding powder material, the feeder device comprising: a feed channel having a downstream end, the feed channel accommodating at least one conveying element for conveying the powder material to the downstream end; and a rotatable outlet element at the downstream end of the feed channel, the rotatable outlet element including an annular portion defining an outlet opening defined by a powder-bonding edge.

[0003] For the production of pharmaceutical tablets, the raw material composition can include excipients and compounds such as so-called active pharmaceutical ingredients (APIs). These excipients are generally pharmacologically inactive components added to the API to act as fillers or matrix, such as magnesium stearate and optionally additional additives. These compounds are typically in particulate form, which may require granulation (agglomeration) to improve their flowability during transport and other process characteristics required to enable subsequent tablet compaction in a tableting machine. Many granulation techniques are available, depending on the type of API used and the desired tablet characteristics, such as granulation equipment, including dry granulation in, for example, milling mills, melt granulation or wet granulation in extruders, spheronizers, fluidized bed spray granulators, high-shear granulators, or twin-screw wet granulation combined with fluidized bed drying.

[0004] In this document, powder or powder material is defined as a collection of finely fragmented solid substances comprising one or more compounds, wherein any given percentage of these substances may be in a granular state, i.e., an agglomerated (dry) state. Furthermore, as a construct, all or any air or gas between and within the powder, as well as moisture, are considered to also constitute the powder. Generally, an increased percentage of particulate matter (e.g., 20% higher relative to the powder material by volume or weight) is advantageous because it generally improves flowability, provides better certainty regarding API concentration / distribution, facilitates dissolution in liquids, and facilitates compression.

[0005] To provide a continuous tablet manufacturing process, as opposed to batch processes, easy transfer and delivery of powders and granules, and more precise dosing, are required between raw material containers, up to granulation, and onto the tableting machine. Such transfer and dosing can be achieved using feeders and typically requires a more stable flow of a uniform quantity (one or more) of powder and / or granules per unit time, usually in relatively small amounts over longer or shorter distances. Therefore, more precise and uniformly distributed transport and dosing equipment (such as feeders) is generally advantageous, and particularly for pharmaceutical powder transport and dosing. The term "feed" as used herein generally refers to the movement or transport (flow) of a given quantity (mass per unit time) of material (such as powder), for example, to the next step in the process. The term "dosing" as used herein generally refers to the release of a specific quantity (mass per unit time) of material (such as powder) after feeding, and implies that this quantity is a known, set, or desired quantity over time. Generally, to achieve such a specific quantity, it is desirable to achieve a consistent, so-called uniform flow between processes.

[0006] Feeding and dispensing powder materials with uniform flow, possibly with uniform small volume flow (i.e., with decreasing and uniform mass flow over time), has often proven to be a difficult task, depending on the characteristics of the powder material.

[0007] Such powders can be more or less free-flowing; their flowability is complex and depends on many different factors, such as the physical and chemical properties of the powder and the interactions between particles, as well as its surrounding environment, i.e., contact surfaces, gravity, electrostatic forces, atmospheric or gravitational pressure, temperature, and humidity, which, for example, affect the powder's ability to move and / or adhere together (agglomeration) or adhere to sides (adhesion). The particles and / or agglomerates that constitute the tendency of a powder to agglomerate together are called the powder's cohesiveness, which is more readily observed in practice than it can be quantified, measured, or controlled in advance or, particularly, during transport. Thus, cohesion is the property of powder particles adhering to each other. Adhesion is the property of powder particles adhering to, for example, adjacent surfaces.

[0008] As powder becomes increasingly agglomerated, a certain amount of powder begins to influence the feeding / moving process, causing the powder to move more slowly relative to its constituent parts and thus having a greater tendency to form agglomerates, i.e., to bind large amounts of powder components together, thereby forming visible or physically influential agglomerated shells or surfaces inside or on the powder.

[0009] In steady-state flow, uniform flow feeding and proportioning of powder are ideal conditions to be achieved, but these are difficult or impossible to realize in practice, at least due to the cohesiveness between individual particles and / or agglomerates, as well as other mechanical and chemical interactions, which again depend on the particle size distribution of different particles / granules and their surface properties (such as softness / hardness or shape).

[0010] Therefore, for applications in the pharmaceutical industry, it is advantageous in some applications to be able to feed powder at a uniform rate and / or in relatively small volumes over time, for example, for the production of drug tablets.

[0011] During powder feeding, some powder may tend to clump together due to the pressure differential experienced. Pressure differentials can occur in many different situations: inside the feeder due to gravitational pressure; due to compaction or pressure buildup during feeding; and in the case of screw feeders, such as at the end of the opening / tube / cylinder / container, between the screw and the wall, between the screws, or externally. This can produce undesirable clumps, larger agglomerates (such as shell formations), which depend directly on cohesiveness and other flow characteristics (especially at the outlet, where clumps are pushed forward until gravity pulls them down in a non-uniform manner). In the pharmaceutical industry, it is advantageous to avoid such clumps in some applications because they can lead to so-called "hot spots" of the active pharmaceutical ingredient (API), i.e., non-uniform distribution of API within tablets produced to include the powder thus fed, which can have serious health consequences for the end user when the tablet is taken.

[0012] The accuracy of feeding (whether in batches or continuously) is negatively affected by the size / quality of any clumps that fall from the feeding channel (such as a feeding channel located inside the cylinder) into the receiving (e.g., tablet production) system.

[0013] The applicant has made undisclosed attempts to address this problem by providing a mesh or grid or mold at the end of the cylinder, but pressure may still accumulate on the inside of such a mold, resulting in uneven aggregates, clumps, shells, and pasta-like strips that leave behind the mold / mesh / grid.

[0014] Other attempts to address issues such as clumping include introducing additives to reduce cohesiveness. However, this is often not feasible, for example, in pharmaceutical applications where strict requirements on powder content are applied due to risks to consumers, and in other applications where setting high-quality powder blend properties or further processing is necessary.

[0015] The applicant has also made other attempts in a non-public context, including applying a vibrator or a strong / short-duration impact to the screw section or barrel end section, which are different ways of solving the problem, but may not be suitable for pharmaceutical powders, as they are often sensitive materials that may change their physical / chemical form due to the forces and pressures introduced by such vibrations.

[0016] Furthermore, it is envisioned that air brushes could be used to remove clumps formed during transport or as they leave the feeder by breaking them down.

[0017] The feeder devices mentioned in the introduction are generally known from US2017 / 0274331 A1, which relates to a dispenser for dispensing agricultural chemicals (such as talc and graphite) for seed treatment. The dispenser includes a cylinder and a blade assembly, in which a single screw, preferably a spacer element, is disposed, and the blade assembly has blades similar to a rotatable outlet element. The spacer element provides uniform compaction of the powder to be dispensed before the blade assembly. The blade assembly cuts or breaks the continuous and uniform flow of powder material exiting from the discharge opening. The blade assembly has a diameter smaller than the inner diameter of the cylinder, preferably leaving a radial clearance or play of 0.06” (1.52 mm) (as mentioned in US'331). The cylinder has a lateral recess at its distal end to provide the discharge opening and provides the remainder of the cylinder to extend beyond the discharge opening, thereby providing a shroud protecting the discharge opening from wet and sticky seeds.

[0018] Other feeder devices or dispensing devices that include a feed channel accommodating a conveying element and a rotatable outlet element within the feed channel are known, for example:

[0019] DE 102005048176 B4 discloses an apparatus for filling, for example, bags with a flowable bulk material, the apparatus including a screw in a cylinder and a fine dosing element at the distal end of the cylinder. The fine dosing element includes a star-shaped element (dosing element) that can be positioned in a passive position outside the cylinder for rapid and coarse dosing, and can be positioned in an active position inside the cylinder.

[0020] CN 204587938 relates to a dispenser for seasonings (spices, similar to salt, sugar, pepper, etc.). The dispenser includes a star-shaped wheel and a screw with a reduced pitch, both housed inside a cylinder. The star-shaped wheel functions to provide a uniform and precise dosage, i.e., by preventing premature dispensing of the material.

[0021] The object of the present invention is to provide an improved feeder device by means of the prior art mentioned in the introduction, which avoids or minimizes at least some of the problems mentioned above.

[0022] Another object of the present invention is to provide a feeder device that provides for feeding powder material at a uniform, constant rate (i.e., preferably without clumps of different sizes), and thus allows for more precise dispensing of typically small amounts of powder material.

[0023] Another object of the present invention is to provide a feeder device for feeding powder material without exposing the powder material to excessive pressure gradients in general, thereby reducing the risk of introducing any physical or chemical changes into the powder, which is particularly advantageous when feeding pharmaceutical powders containing sensitive active pharmaceutical ingredients or other pressure-sensitive components.

[0024] This is achieved by positioning a rotatable outlet element adjacent to the downstream end of a feed channel outside the feed channel, which has a first inner diameter, and the rotatable outlet element having a second outer diameter equal to or greater than the first inner diameter. This results in any shell formations formed in the feed channel being engaged by the rotatable outlet element to break down or decompose into smaller parts, such as their constituent parts, like particles or granules. In one embodiment, the rotatable outlet element is positioned directly adjacent to the downstream end of a tubular element (e.g., a cylinder; container; or tube in which the feed channel is disposed). Positioned adjacent to the downstream end of the feed channel, preferably directly adjacent to a cylinder or tube in which the feed channel may be disposed, the rotatable outlet element will engage with powder in use, which is conveyed by the conveying element and exits from the downstream end of the feed channel.

[0025] The term "directly adjacent" includes the end face of a cylinder or tube adjacent to the adjacent side of a rotatable outlet element.

[0026] In short, unlike existing feeders / distributors that have metering devices (such as star elements) located inside the feed channel, inside its cylinder, tube, or container, the outlet element is located outside the feed channel.

[0027] Therefore, these rotatable outlet elements and their powder-engaging edges, in use, will engage the powder leaving the feed channel (e.g., adhesive powder leaving the feed channel as more or less co-adhesive material) after the powder has left the channel, and push the powder in a direction generally perpendicular to the longitudinal direction of the feed channel, thereby breaking down the co-adhesive clumps and shell formations of the powder leaving the feed channel.

[0028] In one embodiment, the at least one conveying element is a rotatable screw element having a rotation axis and a desired direction of rotation. In many different embodiments, rotatable screw elements are known in the art, including interrupted screw elements that include elements arranged along the rotation axis. In different embodiments of the conveying element, the conveying element is a rotatable paddle element carrying paddle-shaped protrusions having a pitch to provide propulsion, for example, of powder, in a direction along the rotation axis.

[0029] In one embodiment, the conveying element has at least one helical ridge extending along the screw element and defining at least one helical valley between the turns of the helical ridge. In a further embodiment, two such rotatable screw elements are provided, having corresponding mutually parallel axes of rotation and preferably having the same intended direction of rotation. The helical ridge of either of the two rotatable screw elements can extend into the helical valley of the adjacent rotatable screw element, and two rotatable outlet elements (one at each end of these conveying elements) can be mounted in staggered positions, with the peripheries of the two rotatable outlet elements thus overlapping each other. By providing two or more screw elements (preferably with ridges extending into adjacent valleys), safe conveying is provided, minimizing the risk of the screw causing powder material to circulate around or even against the conveying direction along the axis of rotation, thereby minimizing the holding time of the powder material in the feed channel and thus minimizing the aggregate amount of pressure applied to and experienced by the powder.

[0030] In a further embodiment, the at least one screw element includes at least one helical ridge having a constant pitch (i.e., the distance between adjacent turns of the helical ridge) or a pitch that increases toward the downstream end. Thus, the risk of accumulated pressure on the powder material due to the reduced pitch i is lower, while providing uniform transport of the powder material. However, those skilled in the art will recognize that in some applications, varying, and even reduced, pitch can have positive functions.

[0031] In one embodiment, the at least one screw element includes at least one helical ridge, and a first clearance exists between the top of the ridge and the inner wall of the feed channel, the first clearance preferably being in the range of 0.5 mm to 2 mm. This results in, on the one hand, that the helical ridge does not scrape against the inner wall of the feed channel, and on the other hand, that material advances efficiently during use.

[0032] In one embodiment, the at least one screw element is a concave screw, which includes at least one helical ridge, and the valley between adjacent turns of the helical ridge has a range of curvature in an axial section passing through the axis of rotation. Thus, it is possible to maintain the clearance between two such rotatable screw elements at a minimum, thereby preventing material from circulating around the rotatable screw element during rotation, thereby achieving the effect of cleaning the valley between adjacent turns of the ridge.

[0033] In one embodiment, the at least one rotatable screw element is a auger type screw element, which includes at least one helical ridge and has a cylindrical bottom portion defining the core of the rotatable screw element in the valley between adjacent turns of the helical ridge.

[0034] In one embodiment, a second clearance exists between the at least one rotatable outlet element and the downstream end of the feed channel / cylinder / tube. This second clearance is in the range of 0 to 8 mm, preferably in the range of 0.1 mm to 5 mm, and more preferably in the range of 0.5 mm to 3 mm. This avoids the risk of the at least one rotatable outlet element rubbing against the end of the feed channel / cylinder / tube, thus abrading particles from the end face or the rotatable outlet element, while ensuring that the size of any agglomerates does not exceed a certain maximum value. When using materials that require, for example, particles that are not prone to abrasion, this clearance can be virtually zero.

[0035] In a practical implementation, the at least one rotatable screw element includes at least one helical ridge, and a third clearance exists between the downstream end of the at least one helical ridge and the rotatable outlet element, the third clearance being in the range of 0 to 11 mm, preferably in the range of 0 to 3 mm. This generally avoids the risk of pressure buildup on the powder material between the downstream end of the screw element and the rotatable outlet element.

[0036] In a further embodiment, the at least one helical ridge extends substantially entirely to the rotatable outlet element. This substantially avoids the accumulation of pressure on the powder material between the downstream end of the screw element and the side surface of the rotatable outlet element facing the screw element.

[0037] In one embodiment, a fourth clearance exists between the overlapping portions of the two rotatable outlet elements, said fourth clearance being in the range of 0.1 mm to 5 mm, preferably in the range of 0 to 8 mm, and more preferably in the range of 0.5 mm to 3 mm. This avoids the risk of the two rotatable outlet elements rubbing against each other and abrading the particles from these rotatable outlet elements, while ensuring that the size of any agglomerates does not exceed a certain maximum value. When using materials that, for example, require particles that do not tend to abrade, this clearance can be virtually zero.

[0038] In a practical embodiment, the at least one rotatable outlet element is flat at least on the side of the annular portion facing the downstream end of the feed channel. In a further embodiment, the annular portion of the rotatable outlet element is flat and has a thickness in the range of 0.5 mm to 5 mm.

[0039] In a practical implementation, the at least one rotatable outlet element is fixed to the at least one rotatable screw element for co-rotating with the at least one rotatable screw element about the rotation axis of the rotatable screw element.

[0040] In one embodiment, the rotatable outlet element includes a central core portion and a plurality of protrusions extending away from the central core portion, wherein, in use, the protrusions define an outlet opening therebetween for the powder material, and each protrusion has a root at the central core portion and a distal end away from the central core portion.

[0041] In a further embodiment, the diameter of the central core portion is equal to or smaller than the core diameter of the rotatable screw element at its downstream end. This core diameter can be defined as twice the distance between the bottom of the at least one helical valley and the central axis (e.g., the axis of rotation). Thus, the path of the fed powder material is not obstructed by the central core portion.

[0042] In a further embodiment, at least two of these protrusions are equidistant from each other about the axis of rotation.

[0043] In a further embodiment, at least two of these protrusions are similar to each other in shape and / or size. These two subsequent embodiments facilitate the manufacture of the outlet element and provide suitable functionality.

[0044] In one embodiment, at least one of these protrusions has a constant width from the root to the distal end. This provides a relatively large space between the protrusions, i.e., a relatively large outlet opening.

[0045] In an alternative implementation, the root of at least one of these protrusions is wider than its distal end. This provides enhanced strength to the protrusion.

[0046] In a further embodiment, at least two roots of adjacent protrusions meet at the central core portion.

[0047] In one embodiment, at least one of these protrusions extends such that the root and the distal end are positioned on a common radius extending from the axis of rotation.

[0048] In one embodiment, at least one of these protrusions extends in a manner that leads the distal end relative to the root in the intended direction of rotation. This provides for pushing the powder material toward the axis of rotation in at least a slightly inward direction.

[0049] In one embodiment, at least one of these protrusions extends in a manner that the distal end trails relative to the root in the direction of rotation. This provides for pushing the powder material away from the axis of rotation in at least a slightly outward direction.

[0050] In one embodiment, at least one of these protrusions has a curvature extending from the root to the distal end. Thus, the powder material can be propelled by a concave surface that provides an agglomeration effect or a convex surface that provides a spreading effect.

[0051] In a further embodiment, at least one of these protrusions extends in a C-shape. Thus, these protrusions can have a range of curvature with constant or helical curvature.

[0052] In a further embodiment, at least one of these protrusions extends in an S-shape and / or a Z-shape.

[0053] In one embodiment, adjacent protrusions define outlet openings that extend radially toward the axis of rotation therebetween, thereby defining the diameter of the central core portion.

[0054] In one embodiment, at least one of these protrusions has at least one extension at its distal end that generally extends in the circumferential direction. This allows the powder material to be contacted radially externally (as viewed relative to the axis of rotation) and further exits from the area enclosed by the extension as the outlet element rotates during use.

[0055] In one embodiment, at least one of these protrusions is interconnected by at least one circumferential ring portion. This provides better strength to the protrusions in a mutually supporting manner, for example, in cases where any composition of the powder material includes a hard material such as hard crystals.

[0056] In a further embodiment, at least one of the distal ends of these protrusions is interconnected via an outer peripheral ring portion.

[0057] In one embodiment, at least one of the protrusions each has a leading edge and a trailing edge, both of which extend along a respective radius extending from the axis of rotation, wherein the leading edge of at least one of the protrusions adjacent to the downstream end relative to the intended direction of rotation is rectangular.

[0058] And / or at least one of these protrusions forms an acute angle with respect to the expected direction of rotation at the leading edge of the downstream end;

[0059] And / or the leading edge of at least one of these protrusions adjacent to the downstream end relative to the expected direction of rotation is rounded or chamfered.

[0060] When the rotatable outlet element is secured to the rotatable screw element, the rotatable outlet element can be releasably fastened, for example by means of a screw connection, by bolts, by a bayonet arrangement, or by other known releasable fastening devices. The feed channel can, for example, be disposed in a cylinder or flexible tube. The cylinder or tube can be attached to, for example, a hopper. The possibility of disassembly may be important, for example, for cleanliness, which is particularly important in the pharmaceutical industry. To disassemble such a cylinder or tube from the hopper, the rotatable outlet element according to the invention may need to be removed before disassembling the cylinder or tube from the hopper. Such removal will be possible when the rotatable outlet element is releasably fastened to the rotatable screw element.

[0061] In an alternative, the rotatable outlet element can be integrally formed with the rotatable screw element, i.e., provided integrally with the rotatable screw element, for example, by welding and / or adhesive or other non-releasable means, as is commonly known to those skilled in the art. In a first alternative, the rotatable screw element itself can be releasable from the conveying element, and the rotatable screw element is mounted to the end of the conveying element, for example, by a screw connection or by a bayonet arrangement.

[0062] As used herein, the term "tube" should be understood as encompassing the body including the feed channel, for example, a rigid body. As used herein, a rigid body should be understood as a body that provides the inner wall of the feed channel, which will not substantially yield under the pressure exerted by the powder during the intended use of the feeder device, and will not substantially bend during normal intended use. Correspondingly, a flexible tube may be able to bend, thereby causing at least a slight bending or deformation of the longitudinal central axis, or thereby allowing at least a small portion of the inner wall of the feed channel to yield under the pressure exerted by the powder.

[0063] In a preferred embodiment, the central axis is a straight line.

[0064] The edges of these protrusions, especially the leading edges intended for rotation, can have any suitable cross-section. Such a cross-section can be defined in a plane tangent to a cylinder coaxial with the axis of rotation and extending at an intermediate radius between the root and distal end of these protrusions. Thus, the cross-section can be rectangular, providing a leading edge perpendicular to the direction of travel during the rotational movement of the protrusion; or it can be triangular, providing an oblique leading edge relative to the direction of travel; the cross-section can be rounded at one or both edges, etc. Any number of edge shapes are suitable, with the aim of reducing the risk of increased pressure gradients experienced by the powder when using this feeder device.

[0065] The material constituting the rotatable outlet element can be any suitable metal, ceramic, polymer, elastomer, or combination thereof; any of its surfaces is preferably easy to clean, especially for pharmaceutical applications. For pharmaceutical applications, non-animal materials may be preferred due to regulations (GMP). Furthermore, the stiffness of the rotatable outlet element, and especially the stiffness of its protrusions, is particularly, but not limited to, having a surface that changes from soft to hard and a flexibility that changes from soft to hard on its side edges, in order to accommodate gentler edge pressure on the powder material fed in the feeder device according to the invention. Even very flexible protrusions, such as feather-like, whisker-like, or brush-like protrusions made of, for example, polymer materials, are conceivable.

[0066] In particular, some pharmaceutical powders require very careful handling because some or all of their components are sensitive materials, such as, in particular, crystalline or otherwise brittle APIs. Any harsh conditions (such as increased pressure gradients experienced during handling, transport, or other processing) can alter or change the physical and / or chemical form of these components. This is especially true for forces and pressures introduced during processing (e.g., in feeder devices). For such powders, the present invention, with a rotatable outlet element positioned outside the feed channel, can provide improved handling, where the powder experiences a reduced pressure gradient.

[0067] In the following, the invention will be explained in more detail by way of non-limiting examples of embodiments with reference to the accompanying drawings, in which...

[0068] Figure 1 This is a perspective view of a feeder device according to a first embodiment of the present invention;

[0069] Figure 2 The tube has been removed. Figure 1 A view of the embodiment shown;

[0070] Figure 3 yes Figure 2 A top view of the feeder device shown;

[0071] Figure 4 This is a front view of the feeder device shown in Figure 1, viewed from the downstream end of the cylinder.

[0072] Figure 5 It shows along Figure 4 The cross section of line VV in the middle;

[0073] Figure 6 Is it like this? Figure 1 Front view of the feed channel in the cylinder of the feeder device shown;

[0074] Figure 7 It has Figure 6 A top view of the feed channel cylinder;

[0075] Figure 8 yes Figure 1 Front view of a pair of rotatable outlet elements of the feeder device shown;

[0076] Figure 9 yes Figure 8 A top view of the rotatable outlet element shown;

[0077] Figure 10 (a) to (f) Figure 14 (a) through (e) illustrate different implementations of the rotatable outlet element;

[0078] Figure 15 yes Figure 10 An enlarged view of the rotatable outlet element shown in (b);

[0079] Figures 16 to 19 It shows different shapes Figure 15 Cross-sections of different embodiments of the feeder device with the protruding leading edge of the rotatable outlet element;

[0080] Figure 20 It is similar to Figure 2 The view shows a feeder device with a conveying element of the type of auger screw element in the second embodiment;

[0081] Figure 21 yes Figure 20 A top view of the feeder device shown;

[0082] Figure 22 This is a view showing a feeder device with a single conveying element in a third embodiment, wherein the cylinder has been removed; and

[0083] Figure 23 yes Figure 22 The top view of the feeder device shown.

[0084] refer to Figures 1 to 9 In a first embodiment of the invention, a feeder device 1 for uniformly feeding powder material includes: a cylinder 3a, inside which a feed channel 3 having a downstream end 5 is provided, the feed channel 3 of the cylinder 3a accommodating a conveying element in the form of two rotatable screw elements 7a, 7b for conveying powder material to the downstream end 5 of the cylinder 3a; and two rotatable outlet elements 9a, 9b at the downstream end 5 (i.e., also downstream of the feed channel). Each of these rotatable outlet elements includes an annular portion 11, which defines a powder-bonding edge 15 (see...). Figure 15 The outlet opening 13 is defined. These rotatable outlet elements 9a, 9b are positioned adjacent to and directly outside the feed channel of the cylinder 3a. In the illustrated embodiment, the cylinder 3a is provided by a generally tubular element. The feed channel of the cylinder 3a includes two converging portions, each having a circular profile (see, for example, [reference needed]). Figure 6 The feed channel 3 (i.e., its two confluence portions) has a first (inner) diameter d, preferably the same diameter, which can be, for example, in the range of 6 mm to 50 mm, preferably in the range of 8 mm to 35 mm, and each of these rotatable outlet elements 9a, 9b has a second (outer) diameter D, which is equal to or greater than, preferably slightly greater than, the first diameter d (e.g., 0 to 8 mm larger).

[0085] By placing these rotatable outlet elements outside the feed channel and providing these rotatable outlet elements with a diameter not less than the diameter of the feed channel, a reduced risk of shell formation between the inner wall of the feed channel and the outer surface of the conveying element is achieved, thereby allowing unimpeded exit from the end of the feed channel. Alternatively, the applicant believes that any clumps formed here are more likely to engage with the side edges of the rotatable outlet elements and be broken into smaller clumps or decomposed into their components (e.g., particles or granules). Furthermore, there is a lower risk that the powder fed through the feed channel will be squeezed or crushed between the radially outward tip or protrusion of the rotatable outlet element and the inner wall of the feed channel. Thus, these rotatable outlet elements 9a, 9b and their powder-engaging edges 15 (see...) Figure 15 In use, after the powder has left the channel, it will join the powder leaving the feed channel 3 (e.g., co-adhesive powder leaving the feed channel 3 as more or less co-adhesive material) and push the powder in a direction generally perpendicular to the longitudinal direction of the feed channel, thereby breaking down the co-adhesive clumps and shell formations of the powder leaving the feed channel.

[0086] Rotatable screw elements 7a and 7b each have rotation axes 7a' and 7b' and a desired direction of rotation. For example... Figure 4 As seen and indicated by arrow 77, the intended direction of rotation is clockwise for both rotatable screw elements 7a, 7b. The actual direction of rotation chosen, of course, depends on how the screw is provided (counterclockwise or clockwise), and the resulting rotations are respectively clockwise and counterclockwise. In this embodiment, each rotatable screw element has helical ridges 17a, 17b that surround and extend along the screw element and define helical valleys 19a, 19b between the turns of the helical ridges. The two rotatable screw elements 7a, 7b are configured to have corresponding mutually parallel axes of rotation 7a', 7b'. The helical ridge 17a, 17b of either of the two rotatable screw elements 7a, 7b extends into the helical valleys 19a, 19b of the adjacent rotatable screw element 7b, 7a, and the two rotatable outlet elements 9a, 9b are mounted in an interleaved position such that the peripheries of the two rotatable outlet elements 9a, 9b overlap each other. By providing two or more screw elements with ridges extending into adjacent valleys, safe transport is provided, minimizing the risk of the screws circulating the powder material around the axis of rotation, thereby minimizing the holding time of the powder material in the feed channel and the amount of pressure applied to the powder.

[0087] In this embodiment, the spiral ridges 17a and 17b have a constant pitch S (see...). Figure 3 It should be noted that, for example, in Figure 3 The screw elements 7a and 7b shown are implemented as double-coil screws, i.e., two helices are coiled around each other. Alternatively, the pitch S can have a value that increases towards the downstream end 5. In contrast to a decreasing pitch that increases the pressure gradient, a constant or (slightly) increasing pitch provides uniform transport of powder with a constant or slightly decreasing pressure gradient.

[0088] In the illustrated embodiment, a first clearance 21 exists between the top of the spiral ridge and the inner wall of the cylinder 3a (i.e., the sidewall of the feed channel 3). This first clearance is preferably in the range of 0.5 mm to 2 mm. Therefore, on the one hand, the spiral ridge does not scrape the wall of the cylinder, and on the other hand, the material (i.e., powder) advances effectively during use.

[0089] exist Figures 1 to 5In the illustrated embodiment, the rotating screw elements 7a and 7b are concave screws, whereby the helical valleys 19a and 19b between adjacent turns of the helical ridges 17a and 17b have a range of curvature in the axial section passing through the respective rotation axes 7a' and 7b'. The clearance between these two rotatable screw elements can be kept reduced, thereby preventing material from circulating on or with the rotatable screw elements during rotation, thus achieving the effect of cleaning the valleys between adjacent turns of the ridges. This type of concave and self-cleaning screw is generally known to those skilled in the art.

[0090] In this embodiment, a second clearance 23 exists between the respective rotatable outlet elements 9a, 9b and the downstream end face 25 of the downstream end 5 defining the feed channel 3 (see [link]). Figure 5 and Figure 9 It should be noted that the downstream end face 25 of cylinder 3a includes a step 27, which is used to accommodate the downstream end face to correspond to the staggered positions of the two rotatable outlet elements, see, for example, [reference needed]. Figure 7 In this embodiment, the second clearance 23 is in the range of 0.1 mm to 5 mm, preferably in the range of 0.5 mm to 3 mm. Due to the second clearance, the side surfaces of the rotatable outlet elements 9a, 9b rotating toward the powder surface do not rub against the end faces (potentially increasing the pressure gradient on that portion of the powder surface in the end faces of the rotatable outlet elements). Furthermore, the reduced size of the second clearance 23 ensures that the size of any clumps passing through does not exceed a certain maximum value and does not provide a volume for the increased pressure to accumulate on the powder leaving from there.

[0091] A third clearance exists between the downstream end of the spiral ridges 17a and 17b and the rotatable outlet elements 9a and 9b, the third clearance being in the range of 0 to 11 mm, preferably in the range of 0 to 3 mm.

[0092] Therefore, in one embodiment, the helical ridge extends to the rotatable outlet element, i.e., the third clearance is approximately zero.

[0093] Overall, the advantage of the third clearance is that it avoids or minimizes the pressure gradient immediately upstream of the rotatable outlet elements 9a and 9b due to the absence of propulsion force other than that generated by the powder material reaching the downstream end 5 of the feed channel 3.

[0094] In this embodiment, which has two rotatable screw elements 7a, 7b and two rotatable outlet elements 9a, 9b with overlapping portions, a fourth clearance 29 exists between the overlapping portions of the two rotatable outlet elements 9a, 9b. In this embodiment, this fourth clearance 29 is in the range of 0.1 mm to 5 mm, preferably in the range of 0.5 mm to 3 mm. The fourth clearance ensures that the two rotatable outlet elements 9a, 9b do not rub against each other during operation, thus preventing wear or damage to powder particles or granules from the rotatable outlet elements 9a, 9b. On the other hand, the fourth clearance should be reduced in size to ensure that the size of any clumps formed when passing between the two rotatable outlet elements 9a, 9b does not exceed a certain maximum value, and does not provide a volume that would build up increased pressure on the powder exiting from there.

[0095] Regarding the third clearance, it should be noted that in this implementation scheme, see [link to relevant documentation]. Figure 5 and Figure 9 These two pairs of rotatable screw elements and rotatable outlet elements are different. Therefore, for the first pair of rotatable screw elements 7a and rotatable outlet elements 9a, the downstream end of rotatable screw element 7a is flush with the adjacent portion of the downstream end face 25, and thus the third clearance is equal to the second clearance 23. However, for the second pair of rotatable screw elements 7b and rotatable outlet elements 9b, the downstream end of rotatable screw element 7b is flush with the downstream end of rotatable screw element 7a, leaving a clearance between the downstream end of rotatable screw element 7b and rotatable outlet element 9a so that the two elements do not collide or wear against each other. Further, in this embodiment, the rotatable outlet elements 9a, 9b are flat at the annular portion including the outlet opening, especially on the side facing the downstream end of the feed channel 3, and specifically, the annular portion of the rotatable outlet element is flat and has a thickness 30 in the range of 0.5 mm to 5 mm. The distance from the downstream end of the spiral ridge 17b to the rotatable exit element 9b (especially its annular portion) will therefore be the sum of the second clearance 23, the thickness 30 of the annular portion of the rotatable exit element 9a, and the fourth clearance 29.

[0096] Step 27, for example, has a height 27a, which is approximately equal to the sum of the thickness 30 of the annular portion of the rotatable exit element 9a and the fourth clearance 29.

[0097] In the embodiments shown in the accompanying drawings, see especially... Figure 4 , Figure 5 , Figure 8 and Figure 9Rotatable outlet elements 9a and 9b are fixed to corresponding rotatable screw elements 7a and 7b so as to rotate together with them about rotation axes 7a' and 7b'. Therefore, each rotatable outlet element 9a and 9b includes a threaded pin 31a and 31b, and each rotatable screw element 7a and 7b includes a threaded hole 33a and 33b for receiving the corresponding threaded pin 31a and 31b. Each rotatable outlet element 9a and 9b includes a slot 35a and 35b for receiving a screwdriver or similar object. Therefore, in this embodiment, the rotatable outlet elements are detachably fixed to the rotatable screw elements. Each rotatable outlet element further includes protrusions 37a and 37b that abut against the downstream end of the corresponding rotatable screw elements 7a and 7b and define a third clearance.

[0098] In this embodiment, the rotatable screw elements 7a and 7b themselves are provided with slots for screwdrivers or the like, wherein the slot 39b of the rotatable screw element 7b is in Figure 5 As can be seen, the rotatable screw elements 7a, 7b can be detached from their respective mountings (not shown), which can be, for example, screw mounts or bayonet mounts. Those skilled in the art will recognize that other mounting configurations are possible. Therefore, the rotatable outlet elements 9a, 9b can be mounted using bayonet mounts or other methods, or the rotatable outlet elements 9a, 9b can be permanently fixed to the respective rotatable screw elements 7a, 7b for removal, for example, for cleaning or maintenance of the feeder device 1.

[0099] Now for reference Figures 10 to 19 The implementation of the rotatable outlet element will be described in more detail. It should be noted that, for the illustrated implementation, clockwise rotation is expected; however, those skilled in the art will recognize that this can be reversed as needed, depending on the design or setup of the feeder equipment.

[0100] Figure 15 The rotatable outlet element 9 is shown, for example... Figures 1 to 5 as well as Figure 8 , Figure 9 The rotatable outlet element 9a or 9b is shown. The rotatable outlet element 9 has a rotation axis 7' extending perpendicular to the plane of the drawing. The rotatable outlet element 9 includes a central core portion 41 and protrusions 43 extending away from the central core portion. These protrusions 43 define an outlet opening 13 therebetween for powder material to be fed by means of the feeder device 1, and each protrusion has a root 47 at the central core portion 41 and a distal end 49 away from the central core portion 41. Similar to rotatable outlet elements 9a and 9b, the rotatable outlet element 9 includes a slot (not shown) for a screwdriver or the like.

[0101] In this embodiment, the central core portion 41 has a diameter at the downstream end of the rotatable screw elements 7a, 7b that is equal to or smaller than the core diameter of the rotatable screw elements 7a, 7b to which the rotatable outlet element 9 should be installed. The core diameter of the rotatable screw elements 7a, 7b can be defined by the bottom of the spiral valleys 19a, 19b. As a result, the path of the fed powder material is not obstructed by the central core portion 41, thereby reducing the risk of increased pressure gradient experienced by the powder.

[0102] Further embodiments of the rotatable outlet element 9 are possible in various ways, as will be shown below:

[0103] In this implementation plan, see Figures 10 to 15 The protrusions 43 are equidistantly spaced around the axis of rotation 7'.

[0104] Furthermore, in this embodiment, all the protrusions are similar in shape and size to each other.

[0105] In some implementation schemes, see Figure 10 a to Figure 10 d, Figure 11 a to Figure 11 f, Figure 12 e to Figure 12 f, Figure 13 a to Figure 13 c Figure 14 a, Figure 14 c Figure 14 e and Figure 15 These protrusions have a constant width from the root to the distal end. This provides a relatively large space between the protrusions, i.e., a relatively large outlet opening 45.

[0106] In the alternative implementation scheme, see Figure 10 e to Figure 10 f, Figure 12 a to Figure 12 d, Figure 13 d and Figure 14 b, the base of these protrusions is wider than the distal end of these protrusions. This provides enhanced strength to protrusion 43.

[0107] Furthermore, in some implementation schemes, see Figure 10 e to Figure 10 f, Figure 12 c to Figure 12 d and Figure 13 The roots of adjacent protrusions meet at the central core portion.

[0108] In some implementation schemes, see especially Figure 10 a to Figure 10f, Figure 13 a, Figure 13 f, Figure 14 a, Figure 14 c Figure 14 e and Figure 15 These protrusions extend in such a way that their root and distal ends are positioned on a common radius extending from the axis of rotation.

[0109] In some implementation schemes, see especially Figure 10 c to Figure 10 d, Figure 11 e Figure 12 a, Figure 12 c Figure 13 c and Figure 14 b, these protrusions extend distally relative to the root in the intended direction of rotation. This provides for pushing the powder material toward the axis of rotation in at least a slightly inward direction.

[0110] In some implementation schemes, see especially Figure 11 f, Figure 12 b, Figure 12 d and Figure 13 b, these protrusions extend in a manner that trails at the distal end relative to the root in the direction of rotation. This provides a propulsion of the powder material away from the axis of rotation in at least a slightly outward direction.

[0111] In some implementation schemes, see especially Figure 11 a, Figure 11 b, Figure 11 e Figure 11 f, Figure 12 c Figure 12 and Figure 14 b, these protrusions have a curvature from the root to the distal end. Thus, the powder material can be propelled by a concave surface that provides an agglomeration effect or a convex surface that provides a spreading effect.

[0112] For further implementation details, see [link to implementation details]. Figure 11 e Figure 11 f, Figure 12 c Figure 12 d and Figure 14 b, these protrusions extend in a C-shape. Thus, these protrusions can have a range of curvatures with constant curvature or helical curvature.

[0113] In other implementation schemes, see Figure 11 a and Figure 11 b, these protrusions extend in an S-shape.

[0114] For other implementation schemes, see Figure 12 e and Figure 12 These protrusions extend in a Z-shape.

[0115] In general, in the illustrated embodiment, adjacent protrusions 43 define an outlet opening 45 extending radially toward the axis of rotation 7' ​​therebetween to define the diameter of the central core portion 41.

[0116] In some implementation schemes, see Figure 11 c Figure 11 d and Figure 14 c, these protrusions have at least one extension at their distal ends that generally extends in the circumferential direction. Thus, the powder material can be contacted from the radially outer side as seen relative to the axis of rotation.

[0117] In some implementation schemes, see Figure 14 a and Figure 14 e, these protrusions are interconnected by at least one circumferential ring portion. Thus, for example, in the case where the powder material comprises hard crystals, better strength is provided to the protrusions in a mutually supporting manner. In such an embodiment, in particular, the distal ends of these protrusions can be interconnected by an outer circumferential ring portion 40. The outer circumferential ring portion 40 has an inner diameter D1, which is preferably not less than, and more preferably greater than, the first diameter d of the feed channel 3.

[0118] In one implementation scheme, see Figure 14 d, each of these protrusions has a leading edge and a trailing edge, both of which extend along a corresponding radius extending from the axis of rotation.

[0119] refer to Figures 15 to 19 The number 51 indicates the downstream end 5 of the rotatable outlet element 7 facing the feed channel 3 and thus exposed to the powder material fed by the rotatable screw element. The powder engagement edge 15 of the protrusion 43 can be implemented in an alternative manner.

[0120] In one implementation scheme, see Figure 16 The powder bonding edge 15 is formed such that the leading edge 15a of the protrusion 43 adjacent to the downstream end relative to the intended rotation direction is rectangular.

[0121] In another implementation scheme, see Figure 17 The powder-bonding edge 15 is formed such that the leading edge 15b of the protrusion 43 relative to the intended direction of rotation near the downstream end forms an acute angle. This embodiment may be disadvantageous for some applications, such as when the powder being fed contains a certain amount of sensitive APIs, where pressure from the sharper powder-bonding edge on the powder being fed may cause physical or chemical changes in these APIs. In fact, the opposite may be a more advantageous embodiment, using the same Figure 17However, the trailing edge of the powder-bonded edge is cut at an acute angle, and the powder is then subjected to lower pressure from the resulting obtuse-angled leading edge.

[0122] In yet another implementation, see Figure 18 The powder bonding edge 15 is formed such that the leading edge 15c of the protrusion adjacent to the downstream end relative to the intended direction of rotation is chamfered.

[0123] In yet another implementation, see Figure 19 The powder bonding edge 15 is formed such that the leading edge 15d of the protrusion adjacent to the downstream end relative to the intended direction of rotation is rounded.

[0124] When applying chamfers or rounded leading edges to the powder bonding edges, a gentler thrust or lateral actuation power can be applied to the powder, which can reduce the risk of pressure buildup on the fed powder.

[0125] The material of the outlet element can be any suitable metal, ceramic, polymer, elastomer, or combination thereof; advantageously, the surface material is easy to clean. Thus, the outlet element can comprise a core of one material and a surface layer of another. This allows the outlet element to be designed with a specific stiffness of the protrusions 43, while providing a more or less hard or soft surface. In particular, the flexibility (bending) of the powder-engaging edge 15 can be designed to accommodate the powder being fed in the feeder; therefore, the more sensitive the powder, the more advantageously the material used should be flexible / resilient, at least in the direction transverse to the flow direction. Generally, non-animal materials may be preferred due to GMP (Good Manufacturing Practice) requirements, such as those used in the pharmaceutical industry. As an example, the outlet element can comprise a stainless steel core and a polymer and / or elastomer surface. Stainless steel is preferred for some embodiments, but ceramics, plastics / polymers / elastomers can also be used. Furthermore, these protrusions can have a brush configuration instead of the impeller-shaped arms shown. Moreover, any combination is possible.

[0126] It should be understood that every different feature associated with the implementation of the exit element (whether it be a different number of spokes, angle, size, inclination or element material) is fully available to a technician to construct the exit element in order to match the requirements of the powder material being conveyed / quantified and the design of the feeder.

[0127] Now for reference Figures 20 to 23 It should be noted that different embodiments of the transmission element are possible within the scope of this invention.

[0128] therefore, Figure 20 and Figure 21An embodiment of a conveying element is shown, comprising two auger screw elements 107a and 107b, each auger screw element including at least one helical ridge 117a and 117b and valleys 119a and 119b between adjacent turns of the helical ridges 117a and 117b. The screw element has cylindrical bottom portions 120a and 120b defining the core of the screw elements 107a and 107b. Figures 1 to 9 The implementation schemes shown are similar. Figure 20 and Figure 21 The embodiments shown include rotatable outlet elements 9a, 9b, etc. It should be noted that, for example, in... Figure 21 The screw elements 117a and 117b shown are implemented as single-coil screws, i.e., a helix extending along its length. This type of auger drill screw element is generally known to those skilled in the art.

[0129] Figure 22 and Figure 23 An embodiment of a conveying element is shown, which includes a single screw element 207, the single screw element comprising (similar to) Figures 1 to 5 The embodiment shown has a concave screw and includes a helical ridge 217 and a valley 219 between adjacent turns of the helical ridge 217. Figures 1 to 9 The implementation schemes shown are similar. Figure 22 and Figure 23 The embodiment shown includes a rotatable outlet element 9. It should be noted that, as... Figure 23 The screw element 207 shown is implemented as a double-coil screw, that is, two helices are coiled around each other.

[0130] In one embodiment, a so-called dispensing flow element (such as an interrupted screw element) may be provided, which includes an element arranged along the axis of rotation and carrying paddle-shaped protrusions having a pitch to provide for advancing powder toward the downstream end 5.

[0131] Other combinations are possible; preferably, at least a portion of (one or more) of the screw is a conveying section. Furthermore, other section designs are possible, including kneading, mixing, cutting, pressure build-up / attenuation, and other element designs described below. Further, as previously mentioned, alternative screw configurations, such as paddles or active elements, are conceivable. Further still, other processes, such as liquid, heating, and weighing applications, can be applied to the conveying / dispensing section here.

[0132] Note: As is known to those skilled in the art, all embodiments of the devices shown and described above may include parts necessary for the operation of the feeding device, such as one or more motors for driving the conveying elements (e.g., the one or more rotating screw elements); auxiliary parts, such as heating or cooling arrangements, weighing equipment, process analysis technology (PAT) such as analytical sensors; and control equipment.

Claims

1. A feeder device (1) for feeding powder material in a uniform flow, comprising: A cylinder (3a) having a feed channel (3) with a downstream end (5) inside, the feed channel (3) of the cylinder (3a) accommodating a conveying element in the form of two rotatable screw elements (7a, 7b) for conveying powder material to the downstream end (5) of the cylinder (3a), and two rotatable outlet elements (9a, 9b) at the downstream end (5), each of the rotatable outlet elements including an annular portion (11) defining an outlet opening (13) defined by a powder bonding edge (15), these rotatable outlet elements (9a, 7b) 9b) is laterally positioned outside the feed channel and positioned adjacent to and directly outside the feed channel of the cylinder (3a), wherein the cylinder (3a) is provided by a generally tubular element, and wherein the feed channel of the cylinder (3a) includes two confluence portions, each having a circular profile, wherein the two confluence portions of the feed channel (3) have a first diameter d, and each of the rotatable outlet elements (9a, 9b) has a second diameter D, which is equal to or greater than the first diameter d, and wherein Two rotatable outlet elements (9a, 9b) have overlapping portions, and there is a clearance (29) between the overlapping portions of the two rotatable outlet elements (9a, 9b).

2. The feeder device according to claim 1, wherein, At least one of the rotatable screw elements includes at least one helical ridge having a constant pitch or a pitch that increases toward the downstream end.

3. The feeder device according to claim 1, wherein, At least one of the rotatable screw elements includes at least one helical ridge, and there is a first clearance between the top of the helical ridge and the inner wall of the feed channel.

4. The feeder device according to claim 1, wherein, At least one of the rotatable screw elements is a concave screw, which includes at least one helical ridge and has a range of curvature in the valley between adjacent turns of the helical ridge in an axial section passing through the axis of rotation.

5. The feeder device according to claim 1, wherein, At least one of the rotatable screw elements is a spiral drill type screw element, which includes at least one spiral ridge and has a cylindrical bottom portion defining the core of the rotatable screw element in the valley between adjacent turns of the spiral ridge.

6. The feeder device according to claim 1, wherein, There is a second clearance between at least one of the rotatable outlet elements and the downstream end face defining the downstream end of the feed channel, the second clearance being in the range of 0 to 8 mm.

7. The feeder device according to claim 1, wherein, At least one of the rotatable screw elements includes at least one helical ridge, and there is a third clearance between the downstream end of the at least one helical ridge and the rotatable outlet element, the third clearance being in the range of 0 to 11 mm.

8. The feeder device according to claim 7, wherein, At least one of the spiral ridges extends substantially entirely into the rotatable outlet element.

9. The feeder device according to claim 1, wherein, The clearance between the overlapping portions of the two rotatable exit elements is in the range of 0 to 8 mm.

10. The feeder device according to claim 1, wherein, At least one of the rotatable outlet elements is flat at least on the side of the annular portion facing the downstream end of the feed channel.

11. The feeder device according to claim 10, wherein, The annular portion of the rotatable outlet element is flat and has a thickness ranging from 0.5 mm to 5 mm.

12. The feeder device according to claim 1, wherein, At least one of the rotatable outlet elements is fixed to the at least one rotatable screw element for co-rotating with the at least one rotatable screw element about the rotation axis of the rotatable screw element.

13. The feeder device according to claim 1, wherein, The rotatable outlet element includes a central core portion and a plurality of protrusions extending away from the central core portion, the protrusions defining an outlet opening therebetween for the powder material, and each protrusion having a root at the central core portion and a distal end away from the central core portion.

14. The feeder device according to claim 13, wherein, The diameter of the central core portion is equal to or less than the core diameter of the rotatable screw element at the downstream end of the rotatable screw element.

15. The feeder device according to claim 13, wherein, At least two of these protrusions are equidistant from each other around the axis of rotation.

16. The feeder device according to claim 13, wherein, At least two of these protrusions are similar to each other in shape and / or size.

17. The feeder device according to claim 13, wherein, At least one of these protrusions has a substantially constant width from the root to the distal end.

18. The feeder device according to claim 13, wherein, At least one of these protrusions has a base that is wider than its distal end.

19. The feeder device according to claim 18, wherein, At least two roots of adjacent protrusions meet at the central core portion.

20. The feeder device according to claim 13, wherein, At least one of these protrusions extends such that the root and the distal end are positioned on a common radius extending from the axis of rotation.

21. The feeder device according to claim 13, wherein, At least one of these protrusions extends in a manner that leads the distal end relative to the root in the intended direction of rotation.

22. The feeder device according to claim 13, wherein, At least one of the protrusions extends in a tailing manner relative to the root in the intended rotational direction.

23. The feeder device according to claim 13, wherein, At least one of these protrusions has a curvature extending from the root to the distal end.

24. The feeder device according to claim 23, wherein, At least one of these protrusions extends in a C-shape, S-shape, or Z-shape.

25. The feeder device according to claim 13, wherein, Adjacent protrusions define these outlet openings that extend radially toward the axis of rotation, thereby defining the diameter of the central core portion.

26. The feeder device according to claim 13, wherein, At least one of these protrusions has at least one extension at its distal end that generally extends in the circumferential direction.

27. The feeder device according to claim 13, wherein, At least two of these protrusions are interconnected by at least one circumferential ring portion.

28. The feeder device according to claim 27, wherein, At least two of these protrusions are interconnected at their distal ends via an outer peripheral loop portion.

29. The feeder device according to claim 13, wherein, At least one of these protrusions has a leading edge and a trailing edge, both of which extend along a corresponding radius extending from the axis of rotation, wherein the leading edge of the at least one of these protrusions adjacent to the downstream end relative to the intended direction of rotation is rectangular or forms an acute angle or is rounded or chamfered.

30. The feeder device according to claim 1, wherein, At least one of the rotatable screw elements includes at least one helical ridge, and there is a first clearance between the top of the helical ridge and the inner wall of the feed channel, the first clearance being in the range of 0.5 mm to 2 mm.

31. The feeder device according to claim 1, wherein, There is a second clearance between at least one of the rotatable outlet elements and the downstream end face defining the downstream end of the feed channel, the second clearance being in the range of 0.1 mm to 5 mm.

32. The feeder device according to claim 1, wherein, There is a second clearance between at least one of the rotatable outlet elements and the downstream end face defining the downstream end of the feed channel, the second clearance being in the range of 0.5 mm to 3 mm.

33. The feeder device according to claim 1, wherein, At least one of the rotatable screw elements includes at least one helical ridge, and there is a third clearance between the downstream end of the at least one helical ridge and the rotatable outlet element, the third clearance being in the range of 0 to 3 mm.

34. The feeder device according to claim 1, wherein, The clearance between the overlapping portions of the two rotatable exit elements is in the range of 0.1 mm to 5 mm.

35. The feeder device according to claim 1, wherein, The clearance between the overlapping portions of the two rotatable exit elements is in the range of 0.5 mm to 3 mm.

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