EP0057356A1 - Device for the controlled discharge of bulk materials from containers - Google Patents

Abstract

A device is provided for the controllable removal of bulk goods from containers with a gas-permeable covering arranged under the container outlet, fastened to a carrier, facing the filling material, a gas connection attached to the carrier and with a closure device. To create a device of this type in order to create a uniform material flow without great mechanical outlay, even for poorly flowable bulk goods with the smallest possible dimensions, the invention provides that the carrier (7) with the gas-permeable covering (9) attached thereon at least partially as a closure part (5) of the container outlet (3) is formed and the closure part (5) can be moved with at least partial release of the container outlet (3). With the new device, substances from containers are dosed into downstream containers, e.g. a balance can be emptied in dosing during negative weighing, and a perfect transition from batch-wise emptying of a container to a continuous flow is guaranteed.

Description

The invention relates to a device for the controllable removal of bulk goods from containers with a gas-permeable covering arranged under the container outlet, fastened to a carrier, facing the filling material, a gas connection attached to the carrier and with a closure device.

Bulk goods of various types and different grain sizes are known to be stored and transferred from the storage containers to other containers for processing, e.g. Scales, volumetric measuring containers, intermediate storage containers etc. There are entire systems here with intermediate conveying devices, and it is understood that the respective container is provided with a closure which has to be opened in order to remove the bulk goods contained in the container. As long as the bulk goods have coarse grain, e.g. Coal, only coarse stones and the like. That is, they have a very good flowability, even for simple closure parts under the respective container outlet there are no difficulties in providing more or less large outflow openings and thus material flows by opening the closure parts more or less. The removal of bulk goods from containers becomes problematic but with poor flow behavior, e.g. due to the high fine content of the bulk material. The finest powders are particularly critical, e.g. Lead oxide, iron oxide, metal oxides in general, but also plasters, cement, clays, etc. It is known that these fine powders - but also bulk goods with coarse granulation - flow poorly from the open container outlet and within the container, which often narrows downwards or at least the narrowing container outlet tend to bridge. For this reason, rubber cushions have already been arranged laterally in the lower region of containers, which can be inflated in order to prevent the formation of bridges and to ensure that the bulk material flows out when the closure part opens an opening. Another possibility for eliminating the bridging of the bulk material located in the lower region of a container is the introduction of compressed air through pipe lances which are inserted laterally across the walls and fastened there, into which e.g. intermittent air is pressed in to destroy the already built bridges of the bulk material.

Usually a container outlet is through a closure member completed, which is movably arranged so that it can open a more or less large opening controlled. There are eccentrically mounted swivel flaps, the pivot point of which is provided on the side of the container outlet, there are also centrally mounted throttle flaps, the rotary shaft of which is arranged in the middle of the material flow, and there are segment closures. Even if the bridging of the bulk material located in the container outlet is eliminated or avoided by the above-mentioned measures, it often shows, despite opening the closure part, that the bulk material does not flow out, but rather suddenly shoots out in an uncontrolled manner when a certain flap angle is reached and then again in the outlet gets stuck. These phenomena are particularly evident in fine powders such as metal oxides or cement. Therefore, rotary valves have been installed in the container outlet, but they are mechanically complex. Another solution was to leave the container outlet with a relatively large opening open at the bottom and to place an allocation device at a distance from it below, onto which the bulk material always falls directly. Despite the inclination of an elongated metering device, the bulk material remained here because it has the observed poor flow properties. Vibrators have therefore already been used and the metering device has been designed as a vibration conveyor. _M recognizes that here, however, a considerable amount of mechanical engineering is required.

This is also not less if the metering device is an air conveyor channel under the open container outlet. The air conveyor trough often extends from the area under the container outlet to the container to which the bulk material is to be fed, often a balance. In the case of bulk goods, not too little fineness has been achieved with moderate success to achieve a uniform material flow via the air conveyor trough to the scale. Disadvantageously, even an air trough fails at large ß fineness, especially when conveying metal oxides, and you could not even achieve a uniform flow of material if additional vibration devices were added. In addition, the maintenance, operating and investment costs of such metering devices are disadvantageously high in addition to the containers. The installation dimensions are also unfavorable because such a system takes up too much operating space.

Another disadvantage, which has been shown in connection with the metering devices, was that the material flow into the downstream container, e.g. the scale is fed. Despite uniform air entry into the channel with a gas-permeable covering, e.g. Sintered metal or sieve mesh, it often happens that the material suddenly and uncontrollably shoots over the air conveyor channel. At least so far it has not been possible to switch off the material flow in good time and accurately when a bulk material is precisely weighed into a downstream balance when the fill level in the balance is reached. It has therefore started to additionally attach a closure part to the end of the metering device. As a result, however, the technical effort is disadvantageously increased even further.

The object of the invention is therefore to create a device of the type described in the introduction in order to create a uniform material flow without great mechanical outlay, even for poorly flowable bulk goods with the smallest possible dimensions. With the new device, the substances from containers are to be metered into downstream containers, e.g. in the event of negative weighing, a scale should be emptied in a metered manner and a smooth transition from batch-wise emptying of a container to a continuous flow should be ensured.

This object is achieved in that the carrier with the air-permeable covering attached to it is at least partially designed as a closure part of the container outlet and the closure part is movable with at least partial release of the container outlet. By designing the closure part, i.e. the closure flap, the segment closure, a slider or the like, as a gas-permeable part or by covering the closure part with a gas-permeable device, but, as mentioned above, the gas-permeable device itself is best designed as a closure part, the investment outlay is no longer required in the known systems described above, and yet the task is solved satisfactorily. The side of the closure part facing the filling material is in fact partially or completely gassed according to the invention, i.e. formed as a distributed gas jet device, so that the filling material lying above the closure part is fluidized to a certain extent. This not only destroys the formation of bridges, it also reduces the friction of the material in itself and against the closure part so that even poorly flowable bulk material can be discharged in a uniform, small material flow even with a small opening. In this way, it is possible to achieve optimum utilization of the conveyor track when feeding a conveyor in batches from a plurality of feed containers arranged one behind the other and to avoid the sudden excessive loading, which has been frequently observed in the known systems.

It is also advantageous according to the invention if the closure part is an eccentrically mounted swivel flap arranged under the container outlet. It has already been stated at the outset that the closure part can of course also be a slide, a single or double segment closure, a centrally mounted throttle valve or the like. The eccentrically pivoted flap is a particularly robust, simply constructed, economical and reliable device with which the advantages sought according to the invention can be achieved.

It is advantageous if, according to the invention, the surface formed by the lower edge of the container outlet is approximately a plane inclined on average to the horizontal. In the case of the pivoting flap mentioned above, it is not only "on the average" but actually essentially a plane which, in some embodiments, can be horizontal, namely if the lower edge of the container outlet also defines a horizontal plane. However, if this plane is inclined to the horizontal, then the essentially flat closure part, namely the pivoting flap, is inclined at approximately the same angle to the horizontal. However, if one thinks of slide closures or segment closure parts, then these do not always have to be arranged symmetrically to the plumb line, as is usually the case, so that the plane laid through these curved surfaces lies horizontally, but this imaginary plane (as a first approximation of the curved surface) can also be arranged inclined to the horizontal. Of course, this applies to double-segment locks as well as two-way swing flaps.

The gas-permeable covering can also be applied to curved as well as to flat surfaces of the closure parts. This covering is preferably sintered metal, sintered-together screen fabric, fabric, ceramic material or other similar porous materials, to name just a few examples. With their help, a substantially uniform distribution of gas is achieved over the gas connection attached to the carrier upward into the bulk material, more or less over the entire area, as desired.

By covering the closure part with the porous, gas-permeable, usually air-permeable material, gas, but mostly air, becomes fluid for the Blown in the filling material above. A minimum opening width of the closure part relative to the lower edge of the container outlet is then often sufficient to allow the material to flow out evenly in the fluidized state. To empty the container completely, the closure part can then additionally be opened completely, if necessary. As already mentioned above, the blowing in of the gas through the porous coating also reduces the friction between the contents of the container and the closure part.

It is possible to arrange a sealing ring between the container outlet and the closure part, e.g. to be attached to the edge of the container. In a further embodiment of the invention, however, it is advantageous if the sealing ring is arranged on the outside around the covering on the side facing the lower edge of the container outlet. This sealing ring can be made of rubber, asbestos, plastic or the like. This ensures a perfect seal between the stationary housing part, i.e. the lower edge of the container outlet, and the movable closure part ensures. Regardless of this, there is the possibility of opening the closure part or a closing flap to different degrees or removing it from the lower edge of the container outlet to different degrees. The gas-permeable coating thus regulates the discharge amount of the material to be treated flowing out of the container. In other words, the opening width of the closure part can be changed by an inclination adjustment and adapted to the desired throughput quantities concerned.

It is also expedient according to the invention if gas supply devices for controlling and / or setting different amounts of gas are provided on the gas connection on the carrier. For example, one can adjust the discharge speed of the filling material on the one hand by the opening width of the closure part, but on the other hand also by the amount of gas that is blown in through the gas-permeable coating towards the filling material side. You can see that with that very simple measures can be used to achieve a very fine regulation of the material flow which is to be controllably withdrawn from containers. The gas is conveniently compressed air, as is available in most industrial plants today. It is also contemplated that a small amount of gas is blown through the gas-permeable covering already when loading the container, from which the filling material will later be drawn off, so that even fluidization of the bulk materials is ensured in the lower container area. In the event of emptying, larger quantities of gas can then be introduced through the gas supply devices, if necessary also providing interval ventilation or periodically blowing in air, so that one can safely remove all types of materials, even the finest powders, from the container in a controllable manner and meter them to another container .

The gas supply can be controlled via a solenoid valve, the gas pressure being adjustable via a pressure reducer. In a preferred embodiment, an automatic circuit was set up which controlled an air supply as required, ventilation being carried out before the closure part was opened, continuous ventilation taking place during the material discharge, and interval ventilation being provided for other applications before the opening and / or during the material discharge. The flap was manually controlled in a first device, and pneumatically in a further development. Of course, other controls, e.g. motor, conceivable. E.g. the opening width of the closure part and thus the container outlet can be adjusted gradually or continuously. In a special embodiment explained below, the step-by-step adjustability is explained.

It is particularly expedient for a further embodiment of the invention if a dustproof housing enclosing the container outlet and the closure part is appropriate. The bulk powders in particular are difficult to empty bulk materials with poor flow properties. Due to the small dimensions of the device according to the invention, it is therefore easily possible to accommodate the entire closure in a dust-tight manner in a relatively small housing.

In an advantageous further embodiment of the invention it is provided that the housing is provided with a gas discharge nozzle. The gas which is supplied through the ventilation, as far as it does not flow into the container, can be discharged via this nozzle.

Due to the small dimensions, even existing systems can be retrofitted with the device according to the invention.

To name just a few possible uses of the device according to the invention: it can be used to discharge material in a defined capacity from a balance for the purpose of slowly feeding it to a downstream process or device; furthermore for dosing from a silo into a balance or into a volume measuring vessel; also for discharge from a silo for the purpose of loading or for loading a downstream conveyor.

There have been particular difficulties with controllable removal, particularly in the field of the battery industry. There was often the problem of discharging lead oxide from a balance into a mixer or metering it into a balance. Due to the device according to the invention, the use of even this difficult-to-flow product no longer presents any difficulties.

Waste sand, cement, lime, clays (ie all aeratable materials) can also be advantageously metered into downstream containers, for example scales, with the upstream containers, for example the silos, in a simple, practical manner can be arranged above the scale. The versatility of the device according to the invention cannot be exhaustively reproduced here.

• Figur 1 schematisch eine Seitenansicht eines Schwenkklappenverschlusses mit luftdurchlässigem Belag auf dem Verschlußteil, d.h. der Schwenkklappe,
• Figur 2 die Draufsicht auf den Schwenkklappenverschluß nach Figur 1,
• Figur 3 eine andere Ausführungsform von Verschlußteil, nämlich ein Zweiwegeverschluß in Gestalt zweier Schwenkklappen und
• Figur 4 eine weitere andere Ausführungsform eines Verschlußteils als Doppelsegmentverschluß.

Further advantages, features and possible uses of the present invention result from the following description of preferred exemplary embodiments in conjunction with the drawings. Show it:

• FIG. 1 schematically shows a side view of a swivel flap closure with an air-permeable coating on the closure part, ie the swivel flap,
• FIG. 2 shows the top view of the swivel flap lock according to FIG. 1,
• Figure 3 shows another embodiment of the closure part, namely a two-way closure in the form of two swivel flaps and
• Figure 4 shows another embodiment of a closure part as a double segment closure.

1, the container outlet 3 fastened to the flange 2, the lower edge 4 of which is sharp-edged and forms an imaginary plane which is inclined to the horizontal at an angle of approximately 45 °. Parallel to this plane is an eccentrically mounted swivel flap which is rotatable about the swivel axis 6. This consists essentially of a carrier 7 with a ring 8 pointing upwards at a distance from its outer circumference to the side of the container outlet 3, which divides the side of the carrier 7 facing the container 1 into two regions. The larger area is in the middle, is circular and has the gas-permeable covering 9, in the case of the embodiments shown here, air-permeable covering. The smaller area is an annular area which is covered with the sealing ring 10. This is therefore arranged under the sharp edge of the lower edge 4 of the container outlet 3 such that a Wall-free sealing of the filling material in the container 1 from the outside is given, because the sealing ring is so wide that it is provided with a safety distance to the right and left of the lower edge 4. The sharp edge of the edge 4 is also provided so that the sealing ring even seals against the edge 4 during the closing process if filling material had previously been poured out and the pivoting flap 5 moves counterclockwise about the pivot axis 6 for closing. The sharp edge then pushes the last leftovers or granules to the right and left to the side.

In the middle, a gas connection 11 is provided under the support 7, through which compressed air is fed through line 12 controlled by an air supply device in the embodiments shown in the figures. The solenoid valve is designated 13 ', while other parts of the compressed air supply, e.g. Pressure reducing valve, not shown.

The entire closure with container outlet 3, swivel flap 5, hose 12 and axis of rotation 6 are enclosed by the dustproof housing 13.

In the embodiment shown in FIG. 1, the swivel flap is actuated by the geared motor 18 and the crank drive 19 (FIG. 2). Three control cams and the associated limit switches 14, 15 and 16 are actuated by cam controls 17. The limit switches preferably go to the "open" or "partial opening" or "close" positions. The drive motor 18 is in turn controlled via these limit switches 14 to 16.

A similar or identical control is also possible in the embodiment in FIG. 3. Here, however, two swivel flaps 5 are provided at an acute angle to each other in the closed position, which can be rotated about the swivel axis 6. In the shown in Figure 3 Position is filling material in the very short container outlet 3 down to the edge along which the two swivel flaps touch each other. If the left flap is opened, the bulk material flows through the. left outlet 21 into a container, not shown, located below, and if the right swivel flap 5 is moved in the counterclockwise direction, then the bulk material flows through the right outlet 22 into a possibly other, also not shown and arranged below.

FIG. 4 shows a double segment closure, in which the closure parts 5 are designed as two separate segments which touch one another along a horizontal lower middle line. If the drive cylinder 23 is charged with flow agent, then it rotates about the pivot axis 6, the segment closure movable on both sides outside the container outlet 3 via crescent-shaped lever 24. It is preferably attached to such a crescent-shaped lever 24 on each side outside the container outlet 3, and the drive lever 24 is also outside the filling material. The latter is provided with a toothed segment 25 which meshes with an opposite toothed segment 26. This is in turn connected to a similar sickle-shaped lever for the other closure segment.

Claims (8)

1. Device for the controllable removal of bulk goods from containers with a gas-permeable covering arranged under the container outlet, fastened on a carrier, facing the filling material, a gas connection attached to the carrier and with a closure device, characterized in that the carrier (7) with the gas-permeable covering (9) fastened thereon is at least partially designed as a closure part (5) of the container outlet (3) and the closure part (5) can be moved with at least partial release of the container outlet (3). 2. Device according to claim 1, characterized in that the closure part (5) is an eccentrically mounted, arranged under the container outlet (3) pivoting flap. 3. Apparatus according to claim 1 or 2, characterized in that the surface formed by the lower edge (4) of the container outlet (3) is approximately a plane inclined on average to the horizontal. 4. Device according to one of claims 1 to 3, characterized in that around the covering (9) around a sealing ring (10) on the lower edge (4) of the container outlet (3) facing side is arranged. 5. Device according to one of claims 1 to 4, characterized in that gas supply devices for controlling and / or setting different amounts of gas are provided on the gas connection (11) on the carrier (7). 6. Device according to one of claims 1 to 5, characterized in that a dustproof housing (13) enclosing the container outlet (3) and the closure part (5) is attached. 7. Device according to one of claims 1 to 6, characterized in that the housing (13) is provided with a gas discharge nozzle. 8. Device according to one of claims 1 to 7, characterized in that the discharge quantity of the material to be treated from the container (1) can be changed by adjusting the opening width of the closure part (5) and / or by regulating the gas quantity or the gas pressure.

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