EP1889797A1 - Metering device - Google Patents

Abstract

The device has a butterfly valve (5) and an insert (4), where the butterfly valve is tiltable in the insert and is vibrated. The butterfly valve is supported in the insert in such a manner that the inert is dimensionally stable during vibration of the butterfly valve. The insert is made of a fixed and hard material, and the butterfly valve has a spindle (52) and a plate (51) supported in the insert. A vibration unit (67) is arranged between the spindle and the insert.

Description

Technical area

The invention relates to a metering device for metering bulk material according to the preamble of independent claim 1.

Such metering devices, which include a flap and insert, wherein the flap is tiltable in use, and wherein the flap is vibratable, may be used to dose various bulk materials in various technical fields.

State of the art

In many industrial processes, such as in various processes of the food industry, agriculture, the chemical industry or the pharmaceutical industry, bulk materials are transferred. The term bulk material is understood here to mean a free-flowing accumulation of particles which are small in relation to the total amount of the bulk material. A bulk material may behave as a fluid under certain conditions, in particular after exceeding an activation energy. The particles are essentially retained or they do not significantly change their shape during transport. The term bulk material includes, in particular, among other building materials such as sand, gravel, gravel or cement; mineral goods such as ore or road salt; Foods such as cereals (rice, wheat, etc.), sugar, table salt, coffee or flour; powdery goods such as pigments or pharmaceutical substances; fillers; Granules and pellets such as pills, iron ore pellets or pressed feed.

When decanting the bulk materials typically metering devices are used, which often include a tiltable in a pipe section or the like flap. When the flap is closed, the pipe section is locked inside so that essentially no more bulk material can pass through the pipe section. Frequently the bulk material source is arranged above the bulk material target, so that the bulk material can be transferred by gravity. In such an arrangement, only the flap is opened for transfer, so that the bulk material can flow through the pipe section. When a desired amount of bulk material is transferred, the flap is closed again. Since bulk materials typically do not begin to flow continuously analogously to liquids or gases when the flap is opened, but flow in relatively large amounts after exceeding an activation energy, no relatively precise amounts of bulk material can be metered with such a metering device. Even when closing the flap, flow of bulk material can not be reduced continuously without further ado, so that with such a metering device, no relatively accurate metering of the amount of bulk material transferred is possible.

In the WO 01/75342 A1 an improved metering device is described which comprises an inserted in a pipe section insert made of an elastically deformable material and a flap with a plate and two journals. The flap is tiltably mounted in use on the arranged in two openings of the insert axle. Furthermore, the metering device has a tilting mechanism acting on one of the axle stubs for tilting the flap and a vibration mechanism acting on both stub axles for vibrating the flap. In operation, to transfer a bulk material, the flap is opened from a closed position by means of the tilting mechanism and at the same time vibrated by means of the vibrating mechanism. About this vibration, the necessary to flow activation energy of the bulk material can be overcome with relatively small flap opening in use, so that relatively small amounts of bulk material or relatively accurate amounts of bulk material can be dosed. Due to the elastic deformation of the insert both in absorbing the vibration movements of the flap and during the tilting of the flap, the plate of the flap rubs against the insert, thereby typically continuously abrading material of the insert. This material On the one hand can contaminate the bulk material, which can significantly affect the bulk material, in particular, for example, in the food industry, in the chemical industry and in the pharmaceutical industry. On the other hand, such abrasion of the material reduces the life of the insert, so that it must be replaced frequently, which can be costly. In addition, the assembly of this metering device is cumbersome because the flap must be pulled over the stretched by an external force use.

The present invention is therefore based on the object to propose a metering device that allows a relatively accurate metering of bulk solids and thereby does not contaminate the bulk materials.

Disclosure of the invention

The object is achieved according to the invention by a metering device, as defined in the independent claim 1. Advantageous embodiments of the inventive metering device emerge from the dependent claims.

The essence of the invention consists in the following: A metering device for metering bulk material comprises a flap and an insert, wherein the flap in the insert is tiltable and wherein the flap is vibratable. Depending on the tilt position of the flap, the insert can be closed or more or less open. When the flap is open, the activation energy of the bulk material necessary for the flow can be overcome by means of the vibration of the flap, which allows a flow of the bulk material with a small flow rate and thus relatively accurate metering.

The flap is stored in use so that the insert is substantially dimensionally stable while the flap vibrates. By such elastically configured vibratable storage of the flap, a deformation of the insert during the vibration of the plate can be avoided. This allows for a customized design of the flap without parts of the flap, such as an edge of a plate, on the use rub. Thus, it can be avoided that during the vibration of the flap material of the insert is rubbed off and at best contaminates the bulk material, which is particularly important, for example, in the case of bulk material from foods or medicaments. Further, in such an embodiment of the metering device, the insert is stressed much less mechanically, so that its service life is relatively high.

The metering device advantageously has a housing in which the insert and the flap are arranged. The housing and the insert are typically designed tubular, so that the use as an inner tube rests tightly against the housing as an outer tube. The housing is preferably connectable to a source of bulk material and a bulk material target so that the bulk material can flow past the flap with the flap open through the insert. The insert may also each have a seal, such as a sealing ring, on its side facing the bulk material source and its side facing the bulk material target to allow a tight connection of the insert to the bulk material source or to the bulk material target.

Preferably, the insert is made of a relatively strong and relatively hard material. By strength is meant in this respect a material property which describes the mechanical resistance that opposes the material of a change in shape. By hardness is here in this regard the mechanical resistance, which opposes a body to the penetration of another body understood. The use of such a material with relatively high strength and hardness allows a simple design of the storage of the flap in use, so that the insert is dimensionally stable, while the flap vibrates. In addition, it can have a relatively long life thanks to its preferred wear behavior. Preferably, the use is further prepared from a harmless for the handling of food and medicines plastic, in particular from one of the United States Food and Drug Administration (FDA) approved plastic. For example, it may be made of polyoxymethylene (POM) and in particular of polyoxymethylene copolymer (POM-C).

In a preferred embodiment, the metering device comprises at least one elastically deformable vibration element and the flap has at least one journal mounted in the insert and a plate. The vibrating element is arranged around the axle journal, between axle journal and insert. In operation, the vibratory movement of the flap and in particular of its journal is absorbed by the vibrating element, so that substantially no vibration is transmitted to the insert during vibration of the flap and the insert does not substantially deform or move accordingly. If the vibrating means is so worn after a certain life by the vibration movements that its expedient effect is compromised, it can typically be replaced in a simple way. The wear of the insert can thereby be significantly reduced, so it must be replaced less frequently.

The vibration element can be designed as a ring, wherein the axle protrudes through the ring. It can be made of any elastically deformable material or in any elastically deformable shape. For example, it may be made of silicone or silicone and polytetrafluoroethylene (PTFE), and in particular as a silicone PTFE ring. Typically, the flap has two journal pins arranged opposite one another on the plate, both of which lie on a common axis about which the flap can be tilted. In this case, a respective vibrating element is preferably arranged around both axle journals, and in particular around both axle journals, two or more vibrating elements mutually offset in the direction of the tilting axis of the flap. With such an arrangement, on the one hand the vibration movements of the flap can be absorbed by the vibration elements and on the other hand arises during the tilting of the flap substantially no oblique pull on the Flap, by means of which the plate is pressed on or in the insert.

Advantageously, the elastically deformable vibration element has a sliding layer on its inside. This sliding layer allows a low-friction movement of the or the axle journal in the vibration element or in the vibration elements during tilting of the flap. As a result, the flap can be tilted with relatively little effort. The sliding layer may be made of PTFE, for example. Further, it may be configured, for example, as a ring with a concave radial outer side for receiving the elastically deformable ring and with a flat inner side.

Advantageously, the metering device comprises means for acting on the vibrating element with a sealing gas. This ensures that no bulk material or dust particles escape from it laterally on the flap.

Preferably, the metering device has a gap between the insert and the plate when the flap is in a closed position in use. Due to the dimensionally stable configuration of the insert, the gap can be so small that the insert can be closed in a dust-tight manner by means of the flap and, at the same time, rubbing of the plate on the insert can be substantially avoided.

Advantageously, the insert has a first part, a second part and connecting means. The first part and the second part are releasably connected to each other by means of the connecting means and the axle journal is mounted between the first part and the second part. As a connecting means, for example, at least one screw can be used, which protrudes through a corresponding hole through the two parts of the insert and is fastened for example by means of a nut. In a dosing device designed in this way, the insert can be disassembled in a simple manner, so that the flap and the vibrating elements can be removed. For sealing the Connection of the two parts of the insert can be arranged between the parts, for example, a ring-shaped seal.

Preferably, the metering device has a tilting mechanism which is connected to the at least one axle journal, wherein an elastomer coupling is arranged between the axle journal and the tilting mechanism. By means of such a tilting mechanism of the axle journal can be rotated about its longitudinal axis, at the same time the plate is tilted. By the elastomeric coupling, which may be configured in particular as an elastomeric dog clutch, the connection between the tilting mechanism and flap is designed to be movable, so that the vibration movement of the flap is not significantly affected by the tilting mechanism.

The tilting mechanism preferably has a pneumatic linear drive for tilting the flap. The linear drive is preferably connected at one end rotatably fixed to the insert, for example via the housing, and on its other side via a lever with the elastomer coupling. With such a linear actuator, the flap can be tilted quickly and reliably compared to frequently used rotary actuators. In addition, such a pneumatic linear drive can be controlled in a reproducible manner by a suitable circuit in a simple manner.

Advantageously, the metering device has a vibrating mechanism with an eccentric rotor and rotating means. The rotor is arranged rotatably on a tilt axis of the flap and the rotor thereby vibrates the flap when the rotation means rotate the rotor. As a means of rotation, for example, a pressurized gas, in particular compressed air, can be used, with which the rotor can be acted upon by appropriately designed in the metering lines. In the case of a flap with two axle journals, the vibration mechanism can be arranged in one of the two axle journals or preferably also in both axle journals.

Brief description of the drawings

In the following, the metering device according to the invention will be described in more detail with reference to the attached drawings with reference to an exemplary embodiment. Show it:

1 shows a side view of an embodiment of a metering device according to the invention;

FIG. 2 is a plan view of the metering device of FIG. 1 with the flap tilted to a closed position; FIG.

Fig. 3 is a side exploded view of the visible in Figure 1 parts of the metering device of Fig. 1.

Fig. 4 is a cross-sectional view of the metering device taken along the line A-A of Fig. 2 with the flap tilted to an open position;

Fig. 5 is a partial exploded view of certain parts of the cross section of Fig. 4; and

Fig. 6 is an exploded view of certain parts of the cross section of Fig. 4. Embodiment (s) of the invention

Certain terms are used in the following description for convenience and are not meant to be limiting. The words "right," "left," "bottom," and "top" refer to directions in the drawing to which reference is made. The terms "inward" and "outward" refer to directions toward or away from the geometric center of the metering device and designated parts thereof. The terminology includes the words expressly mentioned above, derivatives thereof, and words of similar meaning.

In Fig. 1, an embodiment of a metering device according to the invention is shown, which comprises a housing 1 with a pipe section 11 and a fastening part 13. To the pipe section 11 includes upwardly and downwardly in each case a pipe section 11 to the outside superior flange 12 at. On the fastening part 13 of the housing 1, a receptacle 26 is fixedly connected to the first longitudinal end of a pneumatic cylinder 21 of a tilting mechanism 2 rotatably mounted by means of a fixing pin 25. From the second longitudinal end of the cylinder 21 protrudes a piston 22 which is rotatably connected via a fork 23 by means of a fixing pin 27 with the lever 31 of a drive connection 3. The fork 23 and the lever 31 together form a rotatable about the mounting pin 27 joint. The lever 31 opens into a connecting bearing 32 which is mounted on a fixedly connected to the housing 1 projection 33. The fork 23 is covered by an apron 24, which is shown in dashed lines in FIG.

To operate the tilting mechanism 2, the piston 22 is extended out of the cylinder 21 during operation, whereby the fork 23 is moved to the left. This in turn causes the lever 31 is rotated about a rotational axis of the connecting bearing 32 and at the same time the cylinder 21 is rotated together with the piston 22 about the fixing pin 25.

The following definition applies to the entire further description. If reference signs are included in a figure for the purpose of clarity of the drawing, but are not mentioned in the directly related text of the description, their explanation will be referred to in the preceding description of the figures.

As shown in Fig. 2, in the pipe section 11 of the housing 1, a pipe-section-shaped insert 4 is arranged, whose upper and lower edges each have a sealing groove 41. In use 4 a tiltable flap 5 is arranged with a plate 51, wherein between the plate 51 and an inner edge of the insert 4, a gap 53 is configured. In operation, a seal is typically arranged in each of the two seal grooves 41, so that the source of bulk material and the bulk material target can be tightly connected to the metering device. The fastening pin 25 is screwed through the receptacle 26 of the tilting mechanism 2 projecting with the fastening part 13 of the housing 1, so that the receptacle 26 is rotatably mounted on the mounting pin 25. The fork 23 has two branches, between which the lever 31 is arranged, wherein the fixing pin 27 projects through the two branches and the lever 31 therethrough. The fender 24 is by means of Attachment pin 27 and another mounting pin 28 attached to the fork 23.

As best seen in the exploded view of FIG. 3, the attachment pin 27 includes at its one longitudinal end a projection having a smaller diameter than the diameter of the remainder of the attachment pin 27. This extension is inserted into an opening of the fork 23. At its other longitudinal end of the fastening pin 27 by means of a screw (not shown in Fig. 3) screwed to the fender 24. The fastening pin 25 has, at its longitudinal end remote from the fastening part 13 of the housing 1, an annular groove by means of which the receptacle 26 of the tilting mechanism 2 can be secured on the fastening pin 25. The fastening pin 28 is likewise screwed to the protective plate 24 at its one longitudinal end by means of a screw (not shown in FIG. 3).

The upper flange 12 of the housing 1 merges into the fastening part 13 to the right and the pipe section 11 of the housing 1 has a journal receptacle 111, in which a journal of a flap can be arranged so that it passes through the axle journal 111 with the tilt mechanism 2 is connectable.

FIG. 4 shows a cross-section of the metering device according to the invention, with certain parts in FIG. 5 and FIG. 6 being shown in an exploded view for better clarity. The flap 5 has the plate 51 and two opposite, arranged on the tilting axis of the flap on the plate 51 axle journal 52, which each have an outwardly open interior. The axle journals 52 are rotatably mounted between a lower first part 42 and an upper second part 43 of the insert 4, wherein they are each surrounded by two in the direction of the tilt axis of the flap 5 offset from each other, between the axle journal 52 and insert 4, annular vibration elements 67 are surrounded ,

The metering device further has a vibration mechanism 6, which comprises two eccentric rotors 61 configured as imbalance rotors, which are each arranged in the interior of a journal 52. The two rotors 61 are rotatably connected in the direction of the tilting axis of the flap 5 with two adjacent ball bearings 62, so that they are rotatable about the tilting axis of the flap 5. Between the four ball bearings 62 and the respectively associated axle journal 52, a ball bearing seal 63 is arranged in each case. The interiors of the two journal 52 are each closed by an abutment 64 to the outside, which is rotatably mounted in each case with a screw 66. The two screws 66 each have a passage extending in the direction of the tilting axis of the flap 5 and an outwardly projecting compressed air connection 661. Between the two counter bearings 64 and the respectively associated axle journal 52 are each two annular counter-bearing seals 65 are arranged. Afterwards, the two abutments 64 are each non-rotatably connected to a flange shaft 35 which has a passage arranged in the direction of the tilting axis of the flap 5.

The right flange shaft 35 is rotatably connected via an elastomer coupling 7 outwardly with hollow shaft 34 which has a arranged in the direction of the tilt axis of the flap 5 passage. The hollow shaft 34 is rotatably supported via two flange bushings 37 in the two-part connecting bearing 32. Further, it is rotatably connected by means of a spring wedge 36 with the lever 31. The left flange shaft 35 is connected to the outside with a muffler 8, which has an adjacent to the flange 35 foam insert 81 and is closed by a cover 82.

During operation of the metering device, the housing 1 is connected to a source of bulk material and a bulk material target such that, for example, the lower first part 42 of the insert 4 communicates with the bulk material target and the upper second part 43 of the insert 4 is in communication with the bulk material source. In this case, in the two sealing grooves 41 of the first part 42 and the second part 43 each have a sealing ring 45 is arranged to To be able to ensure a tight connection between dosing device and bulk material source or bulk material. Further, the vibrating elements 67 can be acted upon from the outside via two sealing gas channels 44 with sealing gas, so that no bulk material or dust particles thereof can emerge laterally at the axle journal 52.

To open or close the metering device, the flap 5 is tilted in the insert 4 by the lever 31 is rotated about the tilt axis of the flap 5. At the same time so that the hollow shaft 34 is rotated in the connecting bearing 32, and on the elastomeric coupling 7 and the right stub shaft 35 of the right axle journal 52 in the associated vibration elements 67. The right axle pin 52 tilts the plate 51, whereby the left axle journal 52 in the associated vibration elements 67 and the left flange shaft 35 is rotated.

In order to vibrate the flap 5 for metering the bulk material, the two compressed-air connections 661 of the screws 66 are each provided with one through the hollow shaft 34, the elastomer coupling 7 and the right stub shaft 35 or through the cover 82, the foam insert 81 and the left flange 35th connected by a compressed air hose. For vibration, the two rotors 61 are each acted upon by the associated compressed air hose with compressed air, so that they rotate by means of the ball bearings 62 about the tilt axis of the flap 5. Due to the unbalance of the eccentric rotors 61, the flap is vibrated as a whole so that it vibrates.

As best seen in Fig. 5, the four vibrating elements 67 each have an outer, facing the insert elastic ring 671 and an inner, the associated axle journal 52 facing the sliding ring 672. During the vibration of the flap 5, the elastic ring 671 absorbs the vibration movements of the flap 5, so that substantially no vibration movements are transmitted from the flap 5 to the insert 4. The sliding ring 672 has a flat inner surface on which the associated journal 52 during a tilting movement of the flap 5 can be moved with low friction. Further, the elastomeric clutch 7 ensures that the vibration mechanism 6 is movably connected to the tilting mechanism 2, so that the vibration is not inhibited by the rigid tilting mechanism 2. The fact that two mutually offset in the direction of the tilting axis of the flap 5 vibrating elements 67 are arranged on both axle journal 52, during the tilting of the flap 5, a diagonal train that pushes the plate 51 in or on the insert 4, are substantially avoided ,

Claims (10)

Dosing device for dosing bulk goods, comprising a flap (5) and an insert (4), wherein the flap (5) in the insert (4) is tiltable and wherein the flap (5) is vibratable, characterized in that the flap ( 5) is mounted in the insert (4) so that the insert (4) is substantially dimensionally stable while the flap (5) vibrates. Dosing device according to claim 1, wherein the insert (4) is made of a relatively strong and relatively hard material. Dosing device according to one of claims 1 or 2, comprising at least one elastically deformable vibration element (67) and wherein the flap (5) at least one in the insert (4) mounted journal (52) and a plate (51), wherein the vibrating element (67) around the journal (52) around, between the journal (52) and insert (4) is arranged. Dosing device according to claim 3, wherein the elastically deformable vibration element (67) has on its inside a sliding layer (672). Dosing device according to one of claims 3 or 4, comprising means for acting on the vibrating element (67) with a sealing gas (44). Dosing device according to one of the preceding claims, comprising a gap (53) between the insert (4) and the plate (51) when the flap (5) is in a closed position in the insert (4). Dosing device according to one of the preceding claims, in which the insert (4) has a first part (42), a second part (43) and connecting means, wherein the first part (42) and the second part (43) are detachable with each other by means of the connecting means and wherein the journal (52) between the first part (42) and the second part (43) is stored. Dosing device according to one of the preceding claims, comprising a tilting mechanism (2) which is connected to the axle journal (52), wherein between the axle journal (52) and the tilting mechanism (2), an elastomer coupling (35) is arranged. Dosing device according to claim 8, wherein the tilting mechanism (2) comprises a pneumatic linear drive (21, 22) for tilting the flap (5). Dosing device according to one of the preceding claims, comprising a vibration mechanism (6) with an eccentric rotor (61) and rotating means, wherein the rotor (61) is rotatably mounted on a tilting axis of the flap (5) and wherein the rotor (61) the flap (5) vibrates when the rotation means rotate the rotor (61).

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