Device and method for metering pourable feed material
Patent Information
- Authority / Receiving Office
- EP · EP
- Patent Type
- Applications
- Current Assignee / Owner
- QLAR EUROPE GMBH
- Filing Date
- 2024-07-25
- Publication Date
- 2026-06-10
Smart Images
Figure EP2024071084_13022025_PF_FP_ABST
Abstract
Description
[0001] Description
[0002] Title of the invention
[0003] DEVICE AND METHOD FOR DOSING BULK FEED MATERIAL
[0004] field of technology
[0005] The invention relates to a device for dosing pourable feed material with a housing extending along an axis, comprising a base plate, a cover plate arranged at an axial distance therefrom, and a peripheral wall connecting the base plate and cover plate, which enclose a working chamber in which a cellular wheel rotating about the axis is arranged, having a plurality of cells arranged on a number of n circular paths concentrically about the axis, wherein the cells of a first circular path are arranged with a circumferential offset from the cells of a further circular path, and wherein the upper sides of the cells facing the cover plate and the undersides of the cells facing the base plate are open and form chambers rotating with the cover plate and the base plate about the axis, and wherein the housing has an inlet opening, via which the feed material can be fed to the cells of the cellular wheel, and an outlet opening,via which the cells of the cell wheel can be emptied, whereby the filled cells enter the area of the outlet opening during the rotation of the cell wheel and each cell with its cell walls and the outlet opening each forms a partial cross-section A which is dependent on the angle of rotation during the entry, te ii forms.
[0006] The invention further relates to a method for dosing bulk feed material by means of a rotary valve with a rotary housing and a rotary wheel rotating around an axis within the housing, which has a plurality of cells arranged concentrically around the axis on a number of n circular paths, to which the feed material is fed via an inlet opening in the housing and which are emptied via an outlet opening in the housing, wherein the filled cells enter the area of the outlet opening by rotation of the rotary wheel and each cell with
[0007] REPLACEMENT LEAF (RULE 26) its cell walls and the outlet opening each form a partial cross-section Ateii which is dependent on the angle of rotation and is created during the entry.
[0008] State of the art
[0009] Rotary valves are commonly used to meter bulk feed materials in the quantities required for subsequent processes. These are typically located at the material outlet of a storage bin and meter the feed material in the desired quantity into a downstream mechanical or pneumatic conveying device. The feed materials used are particularly free-flowing and / or pourable materials, ranging in size from granules to powders or dusts.
[0010] EP 1 012 545 B1 describes a device for continuous gravimetric dosing and mass flow determination, the dosing rotor having a plurality of pockets arranged on one or more circular paths around the rotational axis. As the dosing rotor rotates, the pockets are filled and emptied in alternating sequences. Since the feed rate depends on the speed of the cellular wheel, the speed of the cellular wheel is regulated to adapt the feed rate to the feed material demand in subsequent processes. To improve dosing accuracy in the event of strongly fluctuating feed material feed, the distance between a pilot control point and the discharge point is determined in accordance with the respective actual speed and / or load of the device.
[0011] DE 102019205 736 A1 discloses a dosing device with a rotary valve for dosing coal dust. Arranged within the housing of the dosing device is a rotary-driven rotary valve with a plurality of rotary valve chambers. These chambers are fed with coal dust via an inlet opening and, as the rotary valve rotates, reach the area of an outlet opening through which they are emptied. A compressed air line is provided in the area of the rotary valve chambers, which swirls the coal dust in the chambers, thereby improving its flowability. This is intended to allow the coal dust to be discharged from the dosing device earlier and more continuously. The aforementioned dosing devices are typically characterized by a feed rate adjustment range of up to 1:5, with a maximum of up to 1:10, which, however, is insufficient for certain processes.For example, in cement production, the ground and mixed raw materials are burned at high temperatures in rotary kilns to produce cement clinker. The fuel is typically a mix of pulverized coal and refuse-derived fuels, with rotary kilns preferably operated with the maximum amount of refuse-derived fuel, and pulverized coal is added only in the amount necessary to maintain constant combustion. Since the calorific values of refuse-derived fuels depend largely on their type, feeding the kilns with varying feedstock leads to widely fluctuating calorific values, which must be compensated for with appropriate dosing of pulverized coal. At the same time, the availability of fuels, even to the point of a failure of the refuse-derived fuels, must be compensated for by appropriate dosing of pulverized coal.Only devices with a large adjustment range can meet these requirements, whereby a pulsation-free feeding of coal dust is particularly important at minimal feed rates.
[0012] Summary of the invention
[0013] Against this background, the object of the invention is to provide a device and a method for dosing bulk feed material in which the feed rate can be regulated within wide limits, in particular also in the range of low feed rates.
[0014] A further object of the invention is to avoid pulsation of the material flow as far as possible when dosing the feed material, especially at low feed rates.
[0015] These objects are achieved by a device of the type described above, wherein the circumferential offset between a first cell of the first circular path and a further cell of the further circular path is designed in such a way that, at the beginning of the entry of the further cell into the area of the outlet opening, the partial cross-section Ateii of the first cell corresponds to x * 1 / n of a full cross-section A V0 n of the first cell, wherein the factor x lies in a range between 0.6 and 1.4. These objects are further achieved by a method of the type described at the outset, in which, after the partial cross-section Ateii of a first cell of a first circular path has been exposed by x * 1 / n of its cross-section, a further cell of a further circular path enters the region of the outlet opening, wherein the factor x lies in a range between 0.6 and 1.4.
[0016] Advantageous further developments of the invention emerge from the subclaims.
[0017] The terms "cross-section", "full cross-section A vo n" and "partial cross-section Ateii" are each to be understood as a cross-sectional area extending perpendicular to the axis of rotation of the cellular wheel.
[0018] A basic concept of the invention is to meter the feed material using a large number of comparatively small cells on a number of n different circular paths of a cellular wheel, with the cells successively delivering the feed material to a conveyor. The invention recognizes the relationship between the relative position of the rotating cells relative to the stationary outlet opening and the continuity of the material flow downstream of the cellular wheel.What is important here is that the cells of the different circular paths are arranged with a circumferential offset v to one another, which, in conjunction with the geometry of the outlet opening, results in one, preferably each, leading cell in the direction of rotation forming a partial cross-section Ateii in the area of intersection with the outlet opening, through which the cell is already emptied before a cell immediately following on from another circular path enters the area of the outlet opening. With a number of n circular paths of the cellular wheel, the offset v of the two cells entering the outlet opening directly one after the other is, according to the invention, such that the leading cell forms a partial cross-section Ateii the size of x * 1 / n of its full cross-section A. V0H with the outlet opening before the immediately following cell enters the area of the outlet opening and in turn begins to form a partial cross-section Ateii. According to the invention, the factor x lies in a range from 0.6 to 1.4, preferably in a range between 0.8 and 1.2. Optimally, the factor x is 1. Compliance with these parameters leads to an even flow of material downstream of the cell wheel, i.e. fluctuations in the quantity of feed material metered are minimized, which allows metering with high precision. Even in the range of low feed rates, a largely constant material discharge is maintained, which enables pulsation-free and precise metering and conveying. Devices and methods according to the invention are therefore characterized by a comparatively large adjustment range for the feed rate, which considerably expands their possible applications.Thus, with the method according to the invention, a feed rate adjustment range of, for example, up to 1:100 is achieved. This ensures high dosing quality, particularly in the lower adjustment range with low feed rates, which is a prerequisite for use in numerous downstream processes, such as fuel dosing.
[0019] These advantages are already clearly evident when the overlap of a leading cell with the outlet opening when the immediately following cell enters the area of the outlet opening is in a range between 0.6 * 1 / n and 1.4 * 1 / n. By further limiting the overlap area to a range between 0.8 * 1 / n and 1.2 * 1 / n, a further increase in the described advantages and effects can be achieved. According to the invention, the best results are achieved with an overlap of 1 / n.
[0020] In implementing the idea of metering the feed material using many, but smaller, cells, an advantageous development of the invention provides for the cell wheel to be as slim as possible, with a comparatively large diameter in relation to the axial thickness of the cell wheel. A large diameter enables the arrangement of a relatively large number of cells in both the radial and circumferential directions, although the volumes available for metering are limited due to the relatively small thickness of the cell wheel. In this embodiment of the invention, the material discharge is made up of a large number of small individual quantities released at different times, which ultimately leads to a significantly more constant material flow.In this sense, a ratio of the axial thickness of the cell wheel to its diameter in a range of less than 1:3, preferably less than 1:4 and most preferably less than 1:5 has proven particularly efficient. According to a preferred embodiment of the invention, the cell wheel has three to five circular tracks, preferably four. Since the outlet opening extends radially over all circular tracks, in this embodiment three to five, preferably four cells successively enter the area of the outlet opening and are emptied before the cycle is repeated with the subsequent cells of the circular tracks. By distributing the feed material to be dosed over several cells, which release the feed material at regular intervals, the continuity of the material flow is improved and the quality of the dosing is increased.
[0021] It is advantageous if all circular tracks of the cellular wheel have the same number of cells. This way, across all circular tracks, each preceding cell can be assigned exactly one cell following on a different circular track, which promotes consistent product discharge. In this regard, a number of cells in a circular track in the range of 24 to 32 has proven particularly advantageous, especially 28.
[0022] Preferably, the cells of a circular path are arranged at a uniform circumferential distance from one another, with the advantage that the emptying of the individual cells of a circular path takes place at a uniform time interval and can thus be better coordinated with the emptying of the cells of other circular paths.
[0023] In an advantageous development of the invention, the full cross section A V0H of all cells is the same, regardless of the circular path on which they are arranged. Since all cells have the same height in the axial direction, all cells have the same volume. Thus, all cells deliver the same amount of feed material during dosing, which also contributes to a more even flow of material. In this sense, suitable full cross-sections A VO H have cross-sectional areas in a range of 15 cm 2 up to 70 cm 2 , preferably 30 cm 2 up to 40 cm 2 .
[0024] With regard to the geometry of the cells of different circular paths, it has proven advantageous if the ratio of radial length r to tangential width u of the individual circular paths is different, with the proviso that the ratio r / u of a radially further inner circular path is greater than the ratio r / u of a radially further outer circular path. The ratio r / u of the individual circular paths therefore becomes smaller from radially inside to radially outside. This is based on the knowledge that the cells of radially further inner circular paths have a lower circumferential speed when the cell wheel rotates than the cells of radially further outer circular paths. This results in different opening behavior of the cells of different circular paths, which is compensated for by this measure to achieve a constant product discharge.
[0025] In an advantageous development of this embodiment, the ratio of radial length r to tangential width u of the cells of a radially inner circular path is greater than 1 and / or the ratio of radial length r to tangential width u of the cells of a radially outer circular path is less than 1. This is accompanied by a change in the longitudinal direction of the cells from a radial orientation in the inner circular path to a tangential orientation in the outer circular path.
[0026] It has also proven advantageous that the implementation of the invention is not restricted to specific cross-sectional shapes of the outlet opening, but can be applied to any cross-section. However, cross-sections of the outlet opening are preferred in which the circumferential section effective for forming the partial cross-sections Ateii is convex or radial. This is the case, for example, with an outlet opening in the shape of a circle, oval, circular ring segment, trapezoid or kidney shape. Due to known geometric sizes and relationships, these embodiments simplify the inventive arrangement of the cells on the individual circular paths with the respective necessary circumferential offset v.
[0027] According to a particularly advantageous embodiment of the inventive concept, it is provided that the wall of a cell leading in the direction of rotation and the outlet opening in the circumferential section forming the partial cross-sections Ateii do not have an identical course in the radial direction until the beginning of the entry of another cell into the area of the outlet opening, so that the rotation angle-dependent course P of a ratio of the partial cross-section Ateii in relation to the full cross-section A V0H of the cell increases more sharply at the beginning of the entry of the further cell than at the beginning of the cell's entry into the area of the outlet opening. In the cell wheels known from practice, the walls of the cells leading in the direction of rotation usually have an identical and thus congruent course with the peripheral edge of the outlet opening in the area delimiting the partial cross-section Ateii during entry into the area of the outlet opening. With leading walls of the cells running straight in the radial direction and outlet openings also delimited in a straight line in the radial direction, each cell enters the outlet opening over the entire length of the leading wall at the beginning of entry, so that the partial cross-section A te ii increases linearly immediately upon entry into the cell. The greater the radial extension of the cell, the more the ratio P of the partial cross-section A teii in relation to the full cross-section A V0 u of the cell. Even if the curve P of the ratio starts at zero at the beginning of the cell's entry into the area of the outlet opening and then increases depending on the rotation of the cellular wheel, the sudden overlap of the cross section of the cell with the outlet opening still leads to noticeable fluctuations in the dosing of the feed material. However, it has been shown that by an initially very small and only later significantly higher increase in the curve P or the increasingly larger ratio of the partial cross section Ateii in relation to the full cross section A V0H of the cell, a low-pulsation yet precise dosing and conveying of the feed material is enabled by a uniformly rotating cell wheel. A non-identical, but rather different, course of the wall of the cell leading in the direction of rotation and the circumferential section of the outlet opening delimiting its partial cross-section Ateii is achieved, for example, by a circular outlet opening in combination with straight, radially extending walls of the cells leading in the direction of rotation, as will be exemplified later in the embodiments.
[0028] It is further considered an advantageous option that the angle-dependent curve P of the ratio, which arises as the cell enters the outlet opening, increases continuously from the beginning of the cell entering the area of the outlet opening in an initial range of the angle of rotation (p), before the curve P shows a linear increase in a middle range. With such an initially very little increasing and gradually increasing curve P of the increasingly larger ratio of the partial cross-section Ateii in relation to the full cross-section A V0 u the cell enables particularly low-pulsation and almost pulsation-free and at the same time very precise dosing and conveying of the feed material with a uniformly rotating cell wheel.
[0029] Likewise, it is further considered advantageous that the rotation angle-dependent profile P of the ratio, which arises as the cell enters the outlet opening, increases less sharply toward the end of the cell's entry into the area of the outlet opening than at the beginning of the entry of the further cell. This can be achieved by ensuring that a wall of the cell opposite the wall leading in the direction of rotation does not have an identical profile to the circumferential section of the outlet opening forming the partial cross-section Ateii of the cell.Both a gradually increasing increase in the profile P of the ratio of the partial cross-section Ateii to the full cross-section Avon of the cell at the beginning of entry into the outlet opening and a gradually decreasing increase in the profile P of the ratio can be realized in a particularly simple manner by the cells each having straight walls in the radial direction and the outlet opening being circular, as is also shown in the following exemplary embodiments. In combination with the circumferential offset between cells on different circular paths specified according to the invention, this enables particularly low-pulsation and precise dosing and conveying of the feed material. Complex monitoring and regulation of the rotation speed of the cell wheel is not required.The cellular wheel designed according to the invention and the outlet opening adapted to it in terms of shape can be manufactured cost-effectively and do not require complex monitoring and control during operation.
[0030] To ensure that the cells of the rotary feeder are emptied as quickly as possible after they enter the discharge opening, a device for supplying compressed air to the rotary feeder is advantageously provided. The feed material is pneumatically conveyed from the cells to the discharge device.
[0031] A servomotor is preferred as the drive for a device according to the invention, which enables continuous regulation of the cellular wheel even at low speeds, thus improving dosing accuracy. Without being limited to this, the invention is explained in more detail below using an exemplary embodiment in the form of a cellular wheel lock shown in the drawing, which will reveal further features and advantages of the invention. The cellular wheel lock has a cellular wheel with cells on four circular paths. The number n is therefore 4.
[0032] Short description of the drawings
[0033] It shows
[0034] Fig. 1 is a vertical section through a device according to the invention,
[0035] Fig. 2 is a view of the underside of the cellular wheel of the device shown in Fig. 1,
[0036] Fig. 3a shows a section of the cellular wheel shown in Fig. 2 on a larger scale in a first rotation angle position I relative to the outlet opening,
[0037] Fig. 3b shows a section of the cellular wheel shown in Fig. 2 on a larger scale in a second rotation angle position II relative to the outlet opening, and
[0038] Fig. 4 a diagram with the curves P1 to P4 of the partial cross sections A te ii of the cells in relation to their full cross-sections A VO H depending on the angle of rotation (p of the cell wheel.
[0039] Description of the embodiments
[0040] Fig. 1 shows a vertical section through a device 1 according to the invention in the form of a horizontal rotary valve. The device 1 has a substantially cylindrical housing 2 extending along an axis 3. The housing 2 comprises a base plate 4 arranged coaxially to the axis 3 and a cover plate 5 arranged at an axial distance and parallel to the axis 3, which are connected along their opposite edges by a peripheral wall 6 and thus enclose a cylindrical working chamber 7. The working chamber 7 is accessible from opposite sides of the housing 2 via an inlet opening 8 in the cover plate 5 and an outlet opening 9 in the base plate 4.
[0041] A tubular material inlet 10 is attached to the top of the cover plate 5, coaxial with the axis 3, to which the discharge hopper 11 of a storage container filled with feed material 12, such as coal dust, is connected. On the underside of the base plate 4, the outlet opening 9 merges into a tubular material outlet 13, which delivers the metered feed material 12 to a conveyor device (not shown).
[0042] In the present embodiment, the outlet opening 9 has a circular shape and is arranged eccentrically to the axis 3 with a circumferential offset of preferably 180° to the inlet opening 8. Other geometries of the outlet opening 9, such as rectangular, trapezoidal, oval, kidney-shaped, or the shape of a circular ring section, are also within the scope of the invention.
[0043] The base plate 4 has a circular opening 14 arranged centrally to the axis 3, into which a cylindrical shaft bearing 15, aligned coaxially to the axis 3, is inserted at one end, while its other end projects freely from the base plate 4. A drive shaft 17 is rotatably mounted in the shaft bearing 15 by means of roller bearings 16. The drive shaft 17 is driven by a servomotor 21, which is power-coupled via a gear 20 and a drive belt 19 to a pulley 18 mounted on the drive shaft 17.
[0044] The upper end of the drive shaft 17 facing the material inlet 10 is formed by a pin 22 that projects through an opening 24 arranged concentrically in the cover plate 5. An agitator 25 is mounted on the pin 22 in a rotationally fixed manner within the material inlet 10, the radial agitator spokes 26 of which rotate around the axis 3 in the material inlet 10 as the drive shaft 17 rotates.
[0045] At the upper end of the drive shaft 17, an annular flange 27 is also provided, which runs around the outer circumference and serves for the rotationally fixed connection of a cellular wheel 28, which is seated coaxially on the drive shaft 17. For this purpose, the cellular wheel 28 has a hub body 29 with a radially projecting annular collar 30, which rests on the annular flange 27 of the hollow shaft 17 and is screwed to it. The cellular wheel 28 fills the entire working chamber 7.
[0046] Axially opposite the base plate 4, one can see, in a merely schematic representation, compressed air lines 36 integrated into the cover plate 5, the individual outlets 37 of which on the underside of the cover plate 5 open into the working chamber 7 in order to supply the cell wheel 28 with compressed air during emptying.
[0047] The detailed design of the cellular wheel 28 is shown in Figs. 2, 3a and 3b. The cellular wheel 28 has a circular ring-shaped disc body 31 which is radially subdivided into four circular paths, namely a radially inner circular path 32.1, a radially semi-inner circular path 32.2, a radially semi-outer circular path 32.3 and a radially outer circular path 32.4, which concentrically revolve around the axis 3 at different radii. All circular paths 32.1 to 32.4 have a circular shape and are formed by cells 33 which are separated in the circumferential direction by narrow radial webs 34 and in the radial direction by narrow annular webs 35. Radial webs 34 and annular webs 35 thus represent the cell walls. Only the cells 33 of the radially outer circular path 32.4 are open to the outside and delimited by the circumferential wall 6.The radial webs 34, which form the front cell walls in the direction of rotation 38, have a bevel 23 extending from the top and bottom of the cell wheel 28, so that the thickness of the radial webs 34 is greatest halfway up the cells 33. Together with the base plate 4, cover plate 5 and peripheral wall 6, the cells 33 form chambers that are closed on all sides and rotate around the axis 3 in the working space 7 during operation of the device 1. The direction of rotation is indicated in Figs. 3a and 3b by the arrow 38. The peripheral speed of the cell wheel 28 is, for example, in a range of up to 1 m / s, depending on the feed rate, and can be continuously throttled down to a standstill.
[0048] All circular paths 32.1 to 32.4 have an identical number of cells 33, and all cells 33 of one and the same circular path 32.1, 32.2, 32.3, or 32.4 are uniformly spaced in the circumferential direction. The cells 33 of different circular paths 32.1 to 32.4 are arranged with a circumferential offset v relative to one another (Fig. 3a, 3b). Regarding the geometric design of the cells 33, relative to a perpendicular plane to the axis 3, all cells 33 of all circular paths 32.1 to 32.4 have an identical axial height and an identical full cross-section A. V0u, so that the volume of all the chambers formed by the cells 33 is also identical. Furthermore, all the cells 33 of one and the same circular path 32.1, 32.2, 32.3 or 32.4 have an identical cross-sectional shape, which preferably corresponds to a segment of a circular ring. In contrast, the cross-sectional shapes of the cells 33 of different circular paths 32.1 to 32.4 differ from one another in that a cell 33 of a radially further inner circular path 32.1, 32.2 or 32.3 has a greater length r in the radial direction and a smaller average width u in the circumferential direction than a cell 33 of a radially further outer circular path 32.2, 32.3 or 32.4. The ratio r / u of the cells 33 of adjacent circular paths 32.1 to 32.4 therefore decreases from the radial inside to the outside. In the present embodiment, the ratio r / u of the cells 33 of the radially inner circular path 32.1 and / or circular path 32.2 is greater than 1 and the ratio r / u of the cells 33 of the radially outer circular path 32.3 and / or circular path 32.4 is less than 1.
[0049] During operation of a device 1 according to the invention, the feed material 12 passes, due to gravity, via the material inlet 10 to the inlet opening 8 in the cover plate 5 and flows there into the open-ended cells 33 of the cellular wheel 28 rotating in the direction of the arrow 38. As can be seen in particular from Figs. 3a and 3b, each filled cell 33 of the circular paths 32.1 to 32.4 reaches the area of the fixed outlet opening 9 during the rotation, wherein the cross section of each cell 33 overlaps in an axial projection with the cross section of the outlet opening 9. The overlapping cross sections form a partial cross section Aten, which is variable depending on the angle of rotation (p) of the cellular wheel 28 and steadily increases from the entry of a cell 33 into the area of the outlet opening 9 until the full cross section A V0H is reached. Emptying of the cell wheel 28 already takes place via the partial cross-section Ateii, even before the cell 33 with its full cross-section A V0 H lies entirely within the area of the outlet opening 9. This applies particularly at low speeds of the cellular wheel 28.
[0050] In the present exemplary embodiment, the arrangement of the cells 33 on the different circular paths 32.1 to 32.4 is selected such that the cells 33 successively entering the outlet cross-section 9 lie on different circular paths 32.1 to 32.4 and are arranged with a circumferential offset v relative to the cell walls leading in the direction of rotation 38. If, for example, a cell 33 of the radially inner circular path 32.1 is assumed to be the cell 33 entering the outlet opening 9 (see Fig. 3b), it is next followed by a cell 33 of the radially half-outer circular path 32.3, which is followed by a cell 33 of the radially outer circular path 32.4 and finally by a cell 33 of the radially half-inner circular path 32.2 (see Fig. 3a), before the sequence cycle begins again with the following cell 33 of the radially inner circular path 32.1.
[0051] The circumferential offset v is selected such that a leading first cell 33 of a first circular path 32.1 to 32.4 is in a position upon entry of an immediately following further cell 33 of another circular path 32.1 to 32.4 in which the partial cross-section Ateii of the leading first cell 33 formed up to that point corresponds to a quarter of its full cross-section A V0 u corresponds to.
[0052] Fig. 3a shows the situation in which a filled cell 33 of the radially semi-inner circular path 32.2 with the cross section A V0 H is about to enter the area of the outlet opening 9. In this first rotational angle position I of the cellular wheel 28, the first cell 33 of the radially outer circular path 32.4, which is immediately ahead in the direction of rotation 38, is already located with a part of its full cross section A V0u in the area of the outlet opening 9. This part thus corresponds to the intersection of the outlet opening 9 with the full cross section A V0 u of the cell 33 and results in the partial cross-section Aten of the first cell 33. At the rotation angle position I shown in Fig. 3a, the partial cross-section A te ii one quarter of the full cross-section A VO H of cell 33. Over this partial cross-section A te ii the emptying of cell 33 already takes place.
[0053] In the course of the continuing rotation, a constantly increasing partial cross-section Ateii of the cell 33 of the radially semi-inner circular path 32.2 results until in a second rotational angle position II of the cell wheel 28 the partial cross-section Ateii corresponds to a quarter of the full cross-section A V0u corresponds to cell 33. This state of the second rotational angle position II is shown in Fig. 3b, in which the immediately following cell 33 of the radially inner circular path 32.1 enters the area of the outlet opening 9. These processes are repeated with the preceding cells 33 of the circular path 32.1 and immediately following cells 33 of the circular path 32.3, as well as the preceding cells 33 of the circular path 32.3 and immediately following cells 33 of the circular path 32.4, before a new sequence cycle begins. In this way, a continuous flow of material is achieved downstream of the cell wheel 28.
[0054] Fig. 4 shows the curves Pi to P4 of the partial cross-sections Ateii, which depend on the angle of rotation (p, in relation to the full cross-sections A V0u of the cells 33 of the individual circular paths 32.1 to 32.4 from entering the area of the outlet opening 9 until they completely overlap. The curve Pi represents the relationship between the cells 33 of the circular path 32.1, the curve P2 that of the cells 33 of the circular path 32.2, the curve P3 that of the cells 33 of the circular path 32.3, and the curve P4 that of the cells 33 of the circular path 32.4. The curves Pi to P4 show similar characteristics with a gradual increase upon entering the area of the outlet opening 9, followed by a steeper, almost linear increase in the middle area, before the curves Pi to P4 flatten out again.
[0055] The 1 / n line is entered in the diagram parallel to the ordinate, whereby in the present embodiment the value 1 / n corresponds to the value 0.25 due to the four circular paths 32.1, 32.2, 32.3, 32.4 of the cell wheel 28.
[0056] It can be seen that at the intersection point of the curve P4 with the 1 / n line, the partial area Ateii of the cell 33 on the radially outer circular path 32.4 has reached a quarter of its full cross-section Avon. This corresponds to a first rotation angle position I at a rotation angle (p) of approximately 10°, which represents the beginning of the curve P2, thus marking the entry of the cell 33 of the radially semi-inner circular path 32.2 into the area of the outlet opening 9 and thus corresponds to the state shown in Fig. 3a.
[0057] During the continued rotation of the cellular wheel 28, the partial cross-section Ateii of the cell 33 of the radially semi-inner circular path 32.2 grows continuously until, upon reaching the second rotational angle position II at a rotational angle (p) of approximately 15°, the profile P2 intersects the 1 / n line, meaning that the partial cross-section Ateii corresponds to a quarter of the full cross-section Avon. In this second rotational angle position II, the profile Pi begins, which shows that the immediately following cell 33 of the inner circular path 32.1 reaches the area of the outlet opening 9 and in turn forms a partial cross-section Ateii. These processes are repeated in the third rotational angle position III with the cell 33 of the radially inner circular path 32.1 as the leading cell 33 and the immediately following cell 33 of the radially semi-outer circular path 32.3, as well as in the fourth rotational angle position IV with the cell 33 of the radially semi-outer circular path 32.3 as the leading cell 33 and the immediately following cell 33 of the radially outer circular path 32.4 before a new sequence cycle begins. In this way, a uniform, pulsation-free flow of material is achieved in the material outlet 13 of the device 1.
Claims
AMENDED CLAIMS received by the International Bureau on 4 December 2024 (04.12.2024) 1. Device for dosing pourable feed material (12) with a housing (2) extending along an axis (3) and comprising a base plate (4), a cover plate (5) arranged at an axial distance therefrom and a peripheral wall (6) connecting the base plate (4) and cover plate (5), which enclose a working space (7) in which a cellular wheel (28) rotating about the axis (3) is arranged, having a multiplicity of cells (33) which are arranged on a number n circular paths (32.1, 32.2, 32.3, 32.4) concentrically about the axis (3), wherein the cells (33) of a first circular path (32.4) are arranged with a circumferential offset v to the cells (33) of a further circular path (32.2) are arranged, and wherein the upper sides of the cells (33) facing the cover plate (5) and the undersides of the cells (33) facing the base plate (4) are open and form chambers rotating with the cover plate (5) and the base plate (4) about the axis (3), and wherein the housing (2) has an inlet opening (8) through which the feed material (12) can be fed to the cells (33) of the cellular wheel (28), and an outlet opening (9) through which the cells (33) of the cellular wheel (28) can be emptied, wherein the filled cells (33) enter the region of the outlet opening (9) during the rotation of the cellular wheel (28) and each cell (33) with its cell walls and the outlet opening (9) each forms a rotation angle-dependent partial cross-section Ateii arising during the entry, characterized in that the circumferential offset v between a in The first cell (33) of the first circular path (32) leading in the direction of rotation (38)4) and a further cell (33) of the further circular path (32. 2) immediately following in the direction of rotation and the outlet opening has a circular shape or kidney shape, such that when the further cell (33) begins to enter the area of the outlet opening (9), the partial cross-section Ateii of the first cell (33) corresponds to x * 1 / n of a full cross-section A. v0 u corresponds to the first cell (33), where x is in a range between 0.6 and 1.
4.
2. Device according to claim 1, characterized in that x is in a range between 0.8 and 1.2, preferably 1. AMENDED SHEET (ARTICLE 19) 3. Device according to claim 1 or 2, characterized in that the cell wheel (28) has three, four or five circular paths (32.1, 32.2, 32.3, 32.4) and preferably four circular paths (32.1, 32.2, 32.3, 32.4) on which the cells (33) are arranged.
4. Device according to one of claims 1 to 3, characterized in that all circular paths (32.1, 32.2, 32.3, 32.4) have an identical number of cells (33), preferably 24 cells to 32 cells, in particular 28 cells.
5. Device according to one of claims 1 to 4, characterized in that the cells (33) of a circular path (32.1, 32.2, 32.3, 32.4) are arranged at a uniform circumferential distance from one another.
6. Device according to one of claims 1 to 5, characterized in that the cells (33) of all circular paths (32.1, 32.2, 32.3, 32.4) have a full cross-section Avon of the same size.
7. Device according to one of claims 1 to 6, characterized in that the full cross section A of the cells (33) is in a range of 15 cm 2 up to 70 cm 2 is preferably in a range of 30 cm 2 up to 40 cm 2 .
8. Device according to one of claims 1 to 7, characterized in that the wall of a cell (33) leading in the direction of rotation (38) has, at least over part of its axial height, a slope (22) relative to the upper side and / or underside of the cell wheel (28).
9. Device according to one of claims 1 to 8, characterized in that the ratio of radial length r to tangential width u of the cells (33) of the individual circular paths (32.1, 32.2, 32.3, 32.4) is different, the ratio r / u of a radially further inner circular path (32.1, 32.2, 32.3) being greater than the ratio r / u of a circular path (32.2, 32.3, 32.4) which is further outer in comparison.
10. Device according to one of claims 1 to 9, characterized in that the ratio of radial length r to tangential width u of the cells (33) AMENDED SHEET (ARTICLE 19) a radially inner circular path (32.1, 32.2, 32.3) is greater than 1 and / or the ratio of radial length r to tangential width u of the cells (33) of a radially outer circular path (32.2, 32.3, 32.4) is less than 1.
11. Device according to one of claims 1 to 10, characterized in that the ratio of the axial thickness of the cellular wheel (28) to its diameter is in a range of less than 1:3, preferably less than 1:4, most preferably less than 1:
5.
12. Device according to one of claims 1 to 11, characterized in that the outlet opening (9) is convex or radial in the circumferential section forming the partial cross sections Ateii.
13. Device according to one of claims 1 to 12, characterized in that the wall of a cell (33) leading in the direction of rotation (38) and the outlet opening (9) in the circumferential section forming the partial cross sections Ateii do not have an identical course in the radial direction until the start of the entry of a further cell (33) into the region of the outlet opening (9), so that the rotation angle-dependent course P of a ratio of the partial cross section Ateii in relation to the full cross section Avon of the cell (33) arising in the course of the entry increases more sharply at the start of the entry of the further cell (33) than at the start of the entry of the cell (33) into the region of the outlet opening (9).
14. Device according to claim 13, characterized in that the angle-dependent profile P of the ratio arising in the course of the cell (33) entering the outlet opening (9) increases continuously from the beginning of the cell (33) entering the region of the outlet opening (9) in an initial range of the angle of rotation (p) before the profile P has a linear increase in a middle range.
15. Device according to claim 13 or claim 14, characterized in that the angle-dependent profile P of the ratio arising during the entry of the cell (33) into the outlet opening (9) is less pronounced towards the end of the entry of the cell (33) into the area of the outlet opening (9). AMENDED SHEET (ARTICLE 19) increases than at the beginning of the entry of the further cell (33).
16. Device according to one of claims 1 to 15, characterized in that the device (1) has a servo motor (21) for driving the cellular wheel (28).
17. Device according to one of claims 1 to 16, characterized by a device for supplying compressed air to the cellular wheel (28), with compressed air outlets (37) which can be supplied with compressed air via compressed air lines (36), wherein the compressed air outlets (37) are axially opposite the outlet opening (9) and are aligned with the circular paths (32.1, 32.2, 32.3, 32.4).
18. Method for dosing bulk feed material by means of a rotary valve with a housing (2) and a rotary valve (28) rotating about an axis (3) within the housing (2), which rotary valve has a plurality of cells (33) arranged concentrically about the axis (3) on a number of n circular paths (32.1, 32.2, 32.3, 32.4), to which cells the feed material (12) is fed via an inlet opening (8) in the housing (2) and which are emptied via an outlet opening (9) in the housing (2), wherein the filled cells (33) enter the area of the outlet opening (9) by rotation of the rotary valve (28) and each cell (33) with its cell walls and the outlet opening (9) each forms a rotation angle-dependent partial cross-section Ateii arising in the course of entry, characterized in that starting from the circular shape or kidney shape the outlet opening (9) a first cell (33) of a first circular path (31.4) forms a partial cross-section Ateii which corresponds to x * 1 / n of its full cross-section A. V0 H, before a further cell (33) of a further circular path (32.2) enters the area of the outlet opening (9), where x is in a range between 0.6 and 1.
4.
19. Method according to claim 18, characterized in that during the rotation of the cellular wheel (28) the angle-dependent profile P of a ratio of the partial cross-section Ateii in relation to the full cross-section A VO H of the cell (33) increases more at the beginning of the entry of the further cell (33) than at the beginning of the entry of the cell AMENDED SHEET (ARTICLE 19) (33) into the area of the outlet opening (9).
20. Method according to claim 19, characterized in that during the rotation of the cellular wheel (28) the angle-dependent profile P of the Ratio starting from the beginning of the entry of the cell (33) into the area of the outlet opening (9) in an initial range of the angle of rotation (p) increases continuously, before the course P has a linear increase in a middle range. AMENDED SHEET (ARTICLE 19)