Conveying devices for bulk material, system comprising a conveying device of this type and method for cleaning a conveying device

Abstract

The present invention relates to controlled dispensing devices for bulk material, to a system comprising a controlled dispensing device of this type and to a method for cleaning a controlled dispensing device.

Description

[0001] Conveying devices for bulk material, a system comprising such a conveying device, and a method for cleaning a conveying device Description Field of the art The present invention relates to conveying devices for bulk material, a system comprising such a conveying device, and a method for cleaning a conveying device. State of the art Conveying devices for conveying bulk material, as well as conveying devices as part of metering devices for metering bulk material, are known from the prior art. The bulk material to be conveyed or metered passes from a receiving unit, such as a container, into a discharge area following the receiving unit in the main conveying direction, from where the bulk material to be conveyed or metered is discharged from the device by means of a discharge element. In a metering device, the discharge takes place in a defined quantity,A distinction is usually made between gravimetric and volumetric dosing. Typically, cleaning of the device is necessary, especially when changing the type of bulk material, in order to avoid cross-contamination of the bulk material. However, cleaning such a conveying device and its components is time-consuming and costly. Therefore, cleaning measures are carried out as rarely as possible, and frequent changes of the type of bulk material are avoided to avoid cross-contamination. However, this can impair the performance of the device and make it difficult to achieve the highest possible utilization of the device. Summary of the Invention It is therefore an object of the present invention to overcome the disadvantages of the prior art described and, in particular, to provide means that enable efficient and economical cleaning of aConveying device for conveying bulk material or a conveying device as part of a dosing device for dosing bulk material. The object is achieved by the invention according to a first aspect in that a conveying device for bulk material is provided with the features of patent claim 1. The conveying device has at least one receiving unit for receiving bulk material to be conveyed and at least one discharge area, which follows the receiving unit in the main conveying direction and / or into which bulk material can be displaced from the receiving unit, in particular via a bulk material outlet opening of the receiving unit. In addition, the conveying device has a discharge element arranged within the discharge area, which is provided for discharging the bulk material from the discharge area in the direction of a discharge opening of the device. According to the invention,A nozzle for injecting fluid is provided in an area surrounding the discharge element. Alternatively or additionally, the discharge element can be arranged in a floating manner within the discharge area. Furthermore, the discharge element can be or comprise a screw, a trough, a screw, a spiral, a clearing arm, a lock wheel, a cellular wheel, a rotary valve, a lock and / or a roller. The invention is therefore based on the surprising discovery that settled and / or adhering residues of bulk material can be detached particularly reliably and easily from parts of the dosing device that come into contact with the bulk material and transported away in the main conveying direction, supported by a fluid flow formed in the area of ​​the discharge element. Especially hard-to-reach areas of the dosing device can be cleaned of residues of bulk material.can be achieved by injecting a fluid through nozzles, thereby loosening the stuck bulk material. This can advantageously reduce the cleaning time and / or clean the device of larger quantities of settled and / or adhered bulk material in the same or even less time. Above all, the inventors recognized that the proposed cleaning concept can be used without manual intervention. This means that cleaning can also be carried out program-controlled and automatically if required. This not only enables flexible cleaning cycles, but also significantly reduces the comparatively high costs and long downtimes associated with cleaning conveying and dosing devices. Above all, thanks to the proposed concept, the conveying device no longer needs to be opened by a cleaning operator for cleaning, let alone manually removed from the device.settled and / or adhering bulk material can be removed. This also allows conveying devices used to convey or meter hazardous bulk materials to be safely cleaned. This, in turn, increases occupational safety for the people involved. Furthermore, there are no additional or less stringent safety requirements associated with cleaning, as no persons need to be protected from contact with bulk material during cleaning. All of these advantages can significantly reduce the maintenance and operating costs of the conveying and metering device. In an advantageous embodiment, the conveying device has nozzles at various locations around the discharge element. For example, for blowing fluid into a coupling area in which the discharge element is connected to a drive element, such as a drive shaft,A further nozzle or further nozzles can be provided for injecting fluid into a dead space below the discharge element and / or for injecting fluid into the radially existing area between a shaft, possibly a hollow shaft, of the discharge element and an inner surface of a housing forming the discharge area. Advantageously, the nozzle or nozzles can be arranged on or in a bearing element for supporting the discharge element and / or on or in a shaft of the discharge element. Depending on their arrangement and orientation, the fluid can be ejected along a direction perpendicular to the direction of gravity or parallel to the main direction of extension of the discharge element. In addition, the fluid can be ejected along a direction perpendicular to the main direction of extension of the discharge element and / or deflected in a direction parallel to the main direction of extension.A further embodiment provides that the nozzle or nozzles eject the fluid in a direction radial to the main direction of extension of the discharge element. In this case, it has been surprisingly discovered that the discharge element can advantageously remain installed during cleaning and can be used to swirl the fluid flow introduced by the nozzle or nozzles. Thus, the cleaning effect can be significantly increased by the presence of the discharge element, which is quite surprising. The coupling area can be a separate and / or at least partially separated area from the discharge area. In this case, too, cleaning with the proposed nozzle is efficient, particularly simple and thorough. The proposed solution is particularly suitable if any bulk material trapped in the coupling area cannot be discharged by the discharge element.efficient and thorough cleaning in particular. The coupling area can be part of a bearing element for supporting the discharge element. In addition, impairments of the discharge element, also and especially in the coupling area, due to trapped bulk material can be avoided or at least reduced by providing one or more of the proposed nozzles. In one embodiment, it can also be advantageous for the device to be designed to actuate, in particular rotate, the discharge element at least temporarily during the ejection of a fluid jet through the nozzle or nozzles. In this way, an advantageous cleaning effect was observed both in the discharge area and in relation to the receiving unit alone. Alternatively or additionally, it can also be provided in the first and / or second aspect of the invention that at least two nozzles are provided, with which in twoopposite directions, fluid can be blown into the area around the discharge element, in particular into the dead space, wherein preferably at least one nozzle is provided at each of the two ends of the discharge area. This makes it particularly advantageous to clean an extended discharge area. A further advantageous embodiment provides that a conveying device for bulk material, the device comprising at least one receiving unit for receiving bulk material to be dosed and at least one further nozzle for at least temporarily ejecting a fluid jet into the receiving unit, wherein the further nozzle is aligned such that an inner surface of the receiving unit can be at least partially exposed to the fluid jet, in order to form, in particular at least within the receiving unit and / or at least partially, a fluid flow in the manner of a cyclone as a cleaning fluid flow.is proposed. The invention is therefore based on the surprising finding that deposited and / or adhering residues of bulk material can be detached particularly reliably and easily from parts of the conveying device that come into contact with the bulk material, supported by a fluid flow formed within the receiving unit, and transported away in the main conveying direction. By forming this fluid flow, referred to as cleaning fluid flow, in the manner of a cyclone at least within the receiving unit, a particularly high level of efficiency can surprisingly be achieved in cleaning the dosing device and its parts. As a result, the cleaning time can be advantageously reduced and / or the device can be cleaned of larger quantities of deposited and / or adhering bulk material in the same or even less time. In an advantageous embodiment, theConveying device has at least two or more than two further nozzles, each for at least temporarily ejecting a fluid jet into the receiving unit, wherein advantageously each of these further nozzles is aligned in such a way that each of several regions of the inner surface of the receiving unit can be at least partially exposed to the respective fluid jet, in order to form within the receiving unit at least partially a fluid flow in the manner of a cyclone as a cleaning fluid flow. When in the present application in connection with the cleaning fluid flow it is mentioned that this is “in the manner of a cyclone”, this is preferably understood to mean (a) that the cleaning fluid flow (i) represents a, in particular three-dimensional and / or turbulent, vortex flow and / or (ii) performs a rotational movement around a central axis of the receiving unit and / or (b) thatFluid components separated due to centripetal force, particularly denser fluid components such as cleaning granules, move along, and particularly in contact with, the inside of the receiving unit, thereby preferably increasing the cleaning effect. The invention thus takes advantage of the fact that residues of bulk material located on the inner surface of the receiving unit can be transported away and detached particularly reliably by a fluid flow or vortex flow. The detached bulk material residues can then be discharged from the device. For example, they can be removed from the device by the discharge element moving them mechanically or by applying a vacuum and sucking out the detached bulk material residues. This allows a change in the type of bulk material to be carried out in a short time, thereby improving the utilization of the conveying device.can be avoided or at least significantly reduced. Electrostatically charged residues of bulk material can also be effectively removed with the proposed concept. In an advantageous embodiment, the ejection from a nozzle takes place over a period of 1 second or longer, preferably 10 seconds or longer, preferably 30 seconds or longer, preferably 60 seconds or longer, and / or 100 seconds or shorter, preferably 60 seconds or shorter. Optionally, the nozzle is configured for a correspondingly long fluid ejection. Preferably, the bulk material to be dosed is a powdery, granular, or lumpy mixture that is or can be in a pourable form. Examples of advantageous bulk materials are rock, building materials, in particular topsoil, sand, gravel and / or cement, raw materials, in particular ore, coal, clay and / orRoad salt, foodstuffs, in particular grain, sugar, salt, coffee and / or flour, and / or powdered goods, in particular pigments, fillers, granules and / or pellets. The fluid of the fluid jet ejected by a nozzle can be or comprise, for example, alcohol, water, a gas, in particular an inert gas or hydrogen, or a gas mixture, such as air, in particular compressed air. The fluid can advantageously be ejected from the first nozzle at an absolute pressure of more than 5 bar, preferably more than 10 bar, preferably more than 20 bar. The main conveying direction advantageously runs from the receiving unit in the direction of the bulk material outlet opening. Alternatively or additionally, it can also be provided that the receiving unit has a, in particular removable, cover and preferably the bulk material feed opening is provided in the cover. The cover enables theReceiving unit can be securely closed. And thanks to a bulk material feed opening provided in the lid, the dosing device can be operated safely, since the interior of the receiving unit cannot be accidentally touched during dosing and / or cleaning operations. For example, the lid can be easily removed for maintenance work on the device in order to have better access to the interior of the receiving unit. It can also be provided that the bulk material outlet opening is opposite the bulk material feed opening or that the bulk material feed opening and bulk material outlet opening have a common central axis. Alternatively, the central axes of the bulk material feed opening and bulk material outlet opening can be different and preferably run parallel or inclined to one another. Alternatively or additionally, it can also be provided that the receiving unit, in particular at leastin some areas, is rotationally symmetrical. This makes the receiving unit particularly easy to use. And a flow in the manner of a cyclone can be formed particularly advantageously. Alternatively or additionally, it can also be provided that the receiving unit has or represents a container and / or, in particular at least in some areas, such as an inner part of the receiving unit, is designed in the shape of a hollow truncated cone. Alternatively or additionally, it can also be provided that the inner surface of the receiving unit is and / or can be brought into contact with the bulk material at least temporarily during the dosing operation of the device and / or wherein the inner surface is designed at least in some areas in the form of a lateral surface of a truncated cone. Alternatively or additionally, it can also be provided that the receiving unit, at least in sections, has ahas a diameter, in particular an inner diameter, which tapers in the direction of gravity. By the receiving unit being designed in the shape of a hollow truncated cone and / or having a decreasing diameter, a pronounced vortex flow can be formed particularly efficiently and reliably within the receiving unit and the spiral course of the fluid flow already mentioned above can be achieved. Alternatively or additionally, it can also be provided that the further nozzle is aligned in such a way, in particular relative to the receiving unit, preferably to the inner surface of the receiving unit, that the fluid jet ejected by the further nozzle can be deflected by means of an impact region of the inner surface of the receiving unit. The deflection can advantageously take place at least partially along a direction of curvature of the inner surface, which direction of curvature corresponds to a direction of rotation of the receiving unit.Alternatively or additionally, it can also be provided that the inner surface has a curved profile at least in some regions, preferably everywhere, along at least one circumferential direction of the receiving unit, and preferably the profile of the impact region is determined, in particular completely or at least partially, by the curved profile. Alternatively or additionally, it can also be provided that the further nozzle is aligned in such a way, in particular relative to the receiving unit, preferably to the inner surface of the receiving unit, that the fluid jet ejected by the further nozzle has a tangential, horizontally extending first velocity component at the point of impact on the inner surface, in particular at the impact region, and in particular the first velocity component is greater than a second velocity component, parallel to the direction of gravity, of the fluid jet ejected by the first nozzle.ejected fluid jet. Thus, the formation in the manner of a cyclone can advantageously result from the interaction between the additional nozzle, in particular its position and orientation, and the receiving unit, in particular the inner surface of the receiving unit. Alternatively or additionally, it can also be provided that the additional nozzle protrudes partially and / or temporarily into the receiving unit, at least during the conveying, dosing and / or cleaning operation of the device. Alternatively or additionally, it can also be provided that the additional nozzle is arranged on the cover of the receiving unit, in particular in such a way that when the cover is closed, the additional nozzle protrudes at least partially into the receiving unit. In this way, existing conveying and dosing devices can be retrofitted particularly economically and with little effort, since only the cover needs to be provided with a corresponding additional nozzle.By providing the additional nozzle on the cover, the necessary modifications to existing conveying devices are limited to a few, easily retrofittable parts. Alternatively or additionally, it can also be provided that the additional nozzle is arranged on the inner surface of the receiving unit, in particular such that the additional nozzle protrudes at least partially into the receiving unit. Alternatively or additionally, it can also be provided that the additional nozzle, in particular at least during the conveying, dosing and / or cleaning operation of the device, is arranged in the receiving unit such that it is positioned above a defined level relative to a maximum permissible fill level of bulk material in the receiving unit during the dosing operation of the dosing device. This is particularly advantageous since it prevents contamination of the additional nozzle withBulk material can be avoided or at least significantly reduced during the conveying operation of the device. This allows manual interventions for cleaning the further nozzle itself to be avoided or at least kept to a minimum. Alternatively or additionally, it can also be provided that the fluid flow and cleaning fluid flow can detach residues of the bulk material from the inner surface of the discharge area and / or the receiving unit and / or that residues of the bulk material detached from the inner surface of the discharge area and / or receiving unit can be transported in the direction of the bulk material outlet opening and / or the discharge opening. This allows the bulk material residues to be removed from the device particularly easily and reliably. Alternatively or additionally, it can also be provided that the device has a storage container for holding a cleaning agent, in particular agranular cleaning agent, such as cleaning granules, and / or is connected or connectable to such a storage container. By using a cleaning agent, the cleaning effect of the cleaning fluid flow can be further increased and the cleaning result improved. Therefore, it is advantageous if the device has a corresponding storage container. As a cleaning agent, for example, a particularly low-elastic, organic and / or inorganic granulate, such as a granulate comprising or consisting of polyethylene and / or polypropylene, can be provided. Particularly advantageously, materials can be provided as cleaning agents that are processed elsewhere in the process and are therefore available. Alternatively or additionally, it can also be provided that the device, in particular in the lid of the receiving unit, has a cleaning agent supply opening for supplying theCleaning agent, in particular from the storage container, into the interior of the receiving unit. This allows the cleaning agent to be supplied to the dosing device particularly reliably. The cleaning agent can, for example, be supplied from the storage container into the interior of the receiving unit via a connecting hose that opens into or passes through the cleaning agent supply opening. Alternatively or additionally, it can also be provided that the further nozzle and / or the cleaning agent supply opening is / are arranged offset from a defined or definable vertical center plane of the receiving unit. This allows the further nozzle to be positioned particularly close to the inner surface / the impact area. In this way, the cleaning fluid flow can be formed particularly reliably. The center plane can, for example, be a vertical center axis of the receiving unit.It goes without saying that the central plane can be a purely conceptual auxiliary construction and does not necessarily have to be present as a physical feature. Alternatively or additionally, it can also be provided that the device is designed to supply the cleaning agent, in particular from the storage container and / or via the bulk material supply opening and / or the cleaning agent supply opening, to the fluid flow, preferably after stable formation of the cleaning fluid flow in the manner of a cyclone. In particular, the cleaning agent is therefore only supplied after the start of the supply of fluid into the interior of the receiving unit. This two-stage process can, on the one hand, achieve a reliable formation of the flow and, on the other hand, easily removable residues of the bulk material can be removed first, before the remaining residues are removed under the action of the cleaning agent. Alternatively orIn addition, it can also be provided that the device is configured to supply the cleaning agent to the ejected fluid jet and / or the cleaning fluid flow, which cleaning agent can preferably be carried along with the cleaning fluid flow at least temporarily and / or at least in sections. In the first option, the cleaning agent is already added to the fluid ejected by the further nozzle. This allows a particularly compact design of the device to be achieved, since no additional openings are required for supplying the cleaning agent to the receiving unit. The cleaning agent can be permanently or at least temporarily added to the fluid to be ejected as a fluid jet. For example, the cleaning agent can be added to the fluid with a time delay, so that a two-stage process as described above can be carried out. Alternatively or additionally,It can also be provided that the cleaning agent can be fed to the receiving unit via a separate opening and / or via the same opening as the bulk material. Alternatively or additionally, it can also be provided that the cover of the receiving unit has the cleaning agent feed opening. Alternatively or additionally, in the aforementioned aspects of the invention, it can also be provided that the discharge opening opens into a discharge element, in particular having a nozzle, a vertical discharge and / or a downpipe, wherein bulk material can preferably be discharged from the dosing device via the discharge element in a direction parallel or inclined, in particular at an angle of less than 90°, to the direction of gravity. The bulk material dosed by the dosing device can be reliably fed to a subsequent process by means of the discharge element. For example, the bulk material can be fed to an extruder in a dosed manner.Likewise, the cleaning agent can also be reliably discharged from the dosing device via the discharge element. Alternatively or additionally, it can be provided that the discharge element has a suction opening for suctioning away fine particles, in particular dust, and / or the suction opening and / or the discharge opening is or can be operatively connected to a suction device for suctioning away dust. In this way, a surprisingly simple and yet reliable possibility has been created for the cleaning agent to strike fine particles, for example bulk material residues, during the cleaning process. If, for example, the cleaning agent is in granular form, the cleaning agent can be guided downwards via the discharge element during the cleaning process along the direction of gravity, and dust particles and / or powdery bulk material residues can be removed from theDosing device can be at least partially sucked away. Alternatively or additionally, it can also be provided that the suction opening points upwards against the direction of gravity. This ensures in a particularly simple yet reliable manner that no or as little as possible cleaning agent, especially in granular form, reaches the suction unit during cleaning. Alternatively or additionally, it can be provided that the conveying device is part of a dosing device, such as a loss-in-weight dosing scale. The functioning of a loss-in-weight dosing scale is generally known to those skilled in the art. The loss-in-weight dosing scale advantageously has at least one weight sensor, for example at least one load cell, so that the weight of a weighed system can be determined at different times. Based on the weight difference at two consecutive times, the amount ofdischarged bulk material. This value, in turn, can be used within the framework of a control loop to discharge a specific quantity of bulk material per unit of time from the dosing device, thus dosing the bulk material to be dosed. The weighed system advantageously has at least the receiving unit with the bulk material to be dosed contained therein, and preferably also the discharge area and / or the discharge element. The object is achieved by the invention according to a third aspect in that a system comprising a conveying device according to the first and / or second aspect of the invention and at least one extruder, wherein preferably (i) the extruder is provided downstream of the device, in particular the receiving unit, the discharge opening and / or the discharge element, in the main conveying direction and / or (ii) the extruder, in particular via the discharge element, bulk material from the conveying device,It was surprisingly discovered that with such a system it is particularly advantageous that the cleaning agent used to clean the conveying device can also be used to rinse the extruder. In particular, this can be done in one operation by feeding the cleaning agent directly to the extruder after it has been discharged from the conveying device, for example, via the discharge element. Therefore, the bulk material to be dosed by the conveying device can advantageously be fed directly to a receptacle of the extruder for feeding bulk material to the extruder (and then the cleaning agent in the same way). In terms of process technology, the extruder is therefore advantageously coupled to the conveying device, in particular the extruder follows the conveying or dosing device in the process chain. Thus, changing the bulk material can be carried out particularly easily andquickly, since the cleaning of the conveying or dosing device and the extruder (i.e. in particular the parts in contact with the bulk material) can be carried out very easily and reliably. Consequently, the proposed system can be operated particularly efficiently and economically, even with different bulk materials. The possibility of quickly changing bulk materials enables a particularly high utilization of the system. Regarding the other associated advantages, reference can be made to the previous explanations regarding the first and second aspects of the invention. These also apply here accordingly. The object is achieved by the invention according to a fourth aspect in that a closure means, in particular a cover, for closing a main opening of a receiving unit of a dosing device according to the first and / or second aspect of the invention, wherein on or in the closure means a nozzle inForm of the further nozzle of the dosing device is proposed. By providing a closure means with a corresponding further nozzle, an existing dosing device can also be retrofitted in a surprisingly simple manner with a functionality for efficient cleaning, in particular a receiving unit. Regarding the associated advantages, reference can be made to the previous explanations regarding the first and second aspects of the invention. These also apply here accordingly. The object is achieved by the invention according to a fifth aspect in that a bearing element for supporting a discharge element of a conveying device according to the first and / or second aspect of the invention, wherein a nozzle of the conveying device is arranged on or in the bearing element, is proposed. By providing a bearing element with a corresponding radially and / or axiallyarranged nozzle or nozzles, an existing conveying device can also be retrofitted in a surprisingly simple manner with a functionality for efficient cleaning, in particular of a discharge area. The object is achieved by the invention according to a sixth aspect in that a use of a cleaning agent, in particular a granular cleaning agent, such as a cleaning granulate, for cleaning at least some parts and / or areas of a conveying device which are or can be brought into contact with a bulk material to be dosed during the conveying or dosing operation of the device, such as at least one receiving unit of the conveying device suitable for receiving bulk material, in particular an inner surface of the receiving unit, and for cleaning and / or rinsing an extruder following the conveying device along a main conveying direction in awork step. It was surprisingly discovered that a particularly simple and economical cleaning of a conveying device and an extruder, which is advantageously filled or can be filled with a bulk material by the conveying device, is possible by using the cleaning agent both for cleaning the conveying device, for example for removing deposited and / or adhering bulk material residues, and for cleaning and / or rinsing the extruder. Furthermore, the technical problem described at the outset is solved by a method according to patent claim 17. In the method for cleaning a conveying device, in particular a previously described conveying device, at least parts of residues of bulk material deposited and / or adhering to an inner surface of the receiving unit or the discharge area of ​​the conveying device are removed and / or removed in the direction of the discharge openingconveyed by forming a fluid flow at least in some areas within the discharge area, the receiving unit and / or a coupling area of ​​the discharge element. Advantageously, residues of bulk material, in particular from dead spaces, are detached by the fluid flow in the discharge area, storage area or coupling area. Furthermore, the method for cleaning a conveying device, which conveying device has a receiving unit for receiving bulk material to be dosed, which can preferably be fed via a bulk material feed opening of the receiving unit and / or can be displaced via a bulk material outlet opening from the receiving unit in the direction of a discharge opening of the device along a main conveying direction, provides that at least parts of residues of bulk material deposited and / or adhering to an inner surface of the receiving unit are detached and / or in the direction of theBulk material can be conveyed to the outlet opening of the receiving unit by forming a fluid flow that is directed downwards at least in some areas as a cleaning fluid flow, at least within the receiving unit. By forming the fluid flow accordingly, the residues of bulk material can be detached from the receiving unit and discharged from the dosing device particularly efficiently. Furthermore, all options that can be provided individually and in any combination in the embodiments of the aforementioned aspects of the invention can be provided in the method, unless the context indicates otherwise. In particular, the physical features of the conveying device described there can also be provided correspondingly in the conveying device here. The features for which the conveying device or parts thereof are set up and / or designed can also be provided as method features.Alternatively or additionally, it can also be provided that the cleaning fluid flow is designed in the manner of a cyclone. Alternatively or additionally, it can also be provided that the cleaning fluid flow is designed within the receiving unit along a flow path, wherein the flow path preferably runs at least in sections and / or at least in regions along a spiral path, in particular with a decreasing diameter, and / or from top to bottom with respect to the direction of gravity. Alternatively or additionally, it can also be provided that the fluid flow is introduced into the receiving unit by a fluid jet ejected from a further nozzle, and wherein the fluid jet is preferably directed obliquely against an inner surface of the receiving unit and preferably at least partially deflecting the fluid flow in a circumferential direction of thereceiving unit. The impact area of ​​the inner surface can be the impact area described above. Alternatively or additionally, it can also be provided that a fluid flow in the manner of a cyclone is formed within at least parts of the receiving unit by an interaction between the fluid jet and / or the fluid flow and the inner surface of the receiving unit. Alternatively or additionally, it can also be provided that a cleaning agent, in particular a granular cleaning agent, such as cleaning granules, is supplied to the fluid flow, which is preferably transported by the fluid flow at least temporarily and / or at least partially along the inner surface of the receiving unit, and in the process, in particular residues of bulk material are detached from the inner surface. For example, the cleaning agent can be supplied via the cleaning agent supply opening and / orBulk material feed opening of the receiving unit. Alternatively or additionally, it can also be provided that the cleaning agent is fed to the fluid flow at a distance from the further nozzle. For example, the further nozzle is provided at a distance from the cleaning agent feed opening. Alternatively or additionally, it can also be provided that the cleaning granulate is fed to the fluid flow through the same opening through which the bulk material is fed to the receiving unit. Alternatively or additionally, it can also be provided that the cleaning agent is fed to the fluid flow after the cyclone has been formed in a stable manner. Alternatively or additionally, it can also be provided that the cleaning agent is introduced into the receiving unit, in particular via the further nozzle, together with the fluid jet as a mixture, in particular as a fluid-cleaning agent mixture. Alternatively or additionally, it can also be providedthat the cleaning agent and a fine fraction are separated from one another after leaving the conveying device, in particular by suctioning off the fine fraction and / or by ejecting the cleaning granulate parallel or inclined to the direction of gravity. In this regard, reference can also be made to the explanations above. Alternatively or additionally, it can also be provided that an extruder following the conveying or dosing device in the main conveying direction is rinsed with the cleaning agent emerging from the conveying device, in particular by guiding the cleaning agent emerging from the conveying device through the extruder. Alternatively or additionally, it can also be provided that the device has at least one discharge area following the receiving unit in the main conveying direction and / or in which the bulk material, in particular via the bulk material outlet opening of the receiving unit, consists ofthe receiving unit is displaceable, and has a discharge element provided within the discharge area for discharging the bulk material from the discharge area in the direction of a discharge opening of the device, wherein preferably, in particular simultaneously with or before or after the formation of a cleaning fluid flow in the receiving unit, (i) a fluid is blown from a nozzle into the discharge area, in particular into an area around the discharge element, such as in an area in the direction of gravity below the discharge element, and / or (ii) a fluid is blown from a nozzle into a coupling area, in which coupling area the discharge element is connected to a drive element, such as a drive shaft. In one embodiment, it can also be advantageous for the device to be designed to, during the ejection of a fluid jet by means of a nozzle, at leastto temporarily actuate the discharge element, in particular to rotate it. In this way, an advantageous cleaning effect was also observed with respect to the receiving unit alone. Alternatively, a fluid, in particular from a second nozzle, can be blown into the discharge area, in particular into an area around the discharge element, such as in an area below the discharge element in the direction of gravity, and / or a fluid can be blown into a coupling area, in which coupling area the discharge element is connected to a drive element, such as a drive shaft. This is based on the surprising finding that even hard-to-reach areas of the dosing device can be cleaned of residues of bulk material by injecting a fluid into the discharge area and / or coupling area, thereby loosening the stuck bulk material.The cleaning process can be carried out particularly efficiently and cost-effectively. Disassembling the dosing device to clean hard-to-reach areas is therefore no longer necessary. It has been discovered, surprisingly, that the discharge element can advantageously remain installed during cleaning and can be used to swirl the introduced fluid flow. Thus, the cleaning effect can be significantly increased by the presence of the discharge element. Furthermore, impairments to the discharge element, especially in the coupling area, caused by trapped bulk material can be avoided or at least reduced by providing one or more of the proposed first and second nozzles. Furthermore, it has been discovered that the use of the fluid flow(s) together with the cleaning fluid flow leads to surprising synergies.Through the combined use, a cleaning result could be achieved that is superior to that which is possible with the sequential use of the individual fluid flows. In addition, the method according to the invention provides for the control of the bulk material feed opening, the discharge element of the conveying device, the nozzle or nozzles, the further nozzle or nozzles, the cleaning agent feed device, the extruder and / or the suction device to be provided individually and in a defined chronological sequence. As a result, mechanical discharge movements by discharge elements and fluid flows for discharging bulk material residues as well as suction processes, if necessary, can be coordinated in time and logically in order to achieve the best cleaning results depending on the type of bulk material. Brief description of the drawings Further features and advantages of the invention will become apparent from the following description, in which preferredEmbodiments of the invention are explained with reference to schematic drawings. These show: Fig. 1a shows a schematic representation of a conveying device according to the invention; Fig. 1b shows a schematic plan view of the conveying device of Fig. 1a; Fig. 1c shows a schematic representation of a receiving unit of the conveying device from Fig. 1a with a sketched cleaning fluid flow in the manner of a cyclone; Fig. 1d shows a schematic representation of a coupling region of the conveying device from Fig. 1a; Fig. 2 shows a schematic representation of an alternative embodiment of a conveying device according to the invention; and Fig. 3 shows a schematic representation of a system according to one aspect of the invention. Description of the Embodiments Fig. 1a shows a schematic representation of a conveying device 1 according to one aspect of the invention. In Fig. 1b, the conveying device 1 is shown schematically from above. TheConveying device 1 has a receiving unit 3, the main opening 5 of which can be closed with a detachable cover 7. A bulk material to be conveyed or metered by the conveying device 1 can be received in the receiving unit 3, which can be fed to the receiving unit 3 via a bulk material feed opening 9 provided in the cover 7. The receiving unit 3 is conically shaped and has an inner diameter that decreases in the direction of gravity (which runs along the negative Y-axis in Fig. 1a). Opposite and below the bulk material feed opening 9 in the direction of gravity is a bulk material outlet opening 11. Bulk material can be displaced from the receiving unit 3 into a discharge area 13 of the device 1 via the bulk material outlet opening 11. Within the discharge area 13, a discharge element 15, here approximately in the form of a spiral, is arranged for discharging the bulk material.from the discharge area 13 in the direction of a discharge opening 17. The discharge opening 17 opens into a vertical discharge 19. Bulk material can be discharged from the conveying device 1 via the vertical discharge 19 parallel to the direction of gravity. The vertical discharge 19 has a suction opening 21 which is operatively connected to a suction device 23 for extracting dust. During the conveying or dosing operation of the device 1, i.e. during the conveying of bulk material, residues 27 of the bulk material to be dosed can, over time, settle and / or adhere to an inner surface 25 of the discharge area 13 and / or the receiving unit 3, as well as to other parts of the device 1. During a planned change of the type of bulk material, these bulk material residues 27 can lead to undesirable cross-contamination and must therefore first be removed. Therefore, in order to avoid cross-contamination, for example during an upcoming change of theIn order to be able to clean the device 1 for different types of bulk material, the conveying device 1 has a plurality of nozzles 29, 39, 45, 52. A fluid jet 43 can be ejected from a nozzle 39 arranged in the coupling area 47 into a dead space 41 below a discharge element 15. This fluid jet 43 is aligned parallel to a longitudinal axis of the discharge element 15. More precisely, the second nozzle 39 can eject the fluid 43 along a direction perpendicular to the direction of gravity, specifically parallel to the main extension direction of the discharge element 15 (i.e., along a direction parallel to the X-axis). On the one hand, it is suitable for discharging bulk material from a coupling area 47 or storage area of ​​the discharge element, which is usually difficult to access. On the other hand, the same fluid jet 43 can be used to remove bulk material from the dead space between the discharge element 15 and the housing wall of the discharge area 13.A fluid jet 31 can be ejected from the further nozzle 29 into the receiving unit 3. The further nozzle 29 is aligned such that the inner surface 25 of the receiving unit 3 can be at least partially flowed against by the ejectable fluid jet 31, so that at least within the receiving unit 3, at least partially, a fluid flow in the manner of a cyclone can be formed as a cleaning fluid flow. The device 1 is therefore particularly designed so that the ejected fluid jet 19 interacts with the inner surface 25 such that said cleaning fluid flow is formed. As can be seen in particular in Fig. 1b, a region of the inner surface 25 is thereby obliquely (along a curvature of the inner surface 25 running along a circumferential direction of the receiving unit 3) by the ejected fluid jet 31. (Of course, in Fig. 1b, due toof the closed lid, the nozzle 27 and the fluid jet 29 as well as the inner surface are not actually visible. However, this has been ignored here for illustrative reasons.) Due to the conical shape of the receiving unit 3, the fluid flow is forced onto a spiral path 33 with decreasing diameter. As a result, the speed of the fluid flow increases continuously. In particular, a vortex flow is formed by the interaction between the ejected fluid jet and the receiving unit (in particular the curved inner surface). Due to this cleaning fluid flow, bulk material residues 27 can be particularly easily removed from the inner surface of the receiving unit. In the lid 7 of the receiving unit 3, a cleaning agent supply opening 35 is provided, through which a cleaning agent can be supplied into the interior of the receiving unit 3. This makes it possible, in particular after aA cyclone was formed within the receiving unit 3 to supply the cleaning agent to the cleaning fluid flow. The cleaning agent can, for example, be in granular form and can be carried along by the cleaning fluid flow temporarily and / or in sections along the spiral path 33. The cleaning agent can also reliably detach more strongly adhering bulk material residues 27 from the inner surface 25. The cleaning agent supply opening 35 is located at a distance from the further nozzle 29, wherein both the further nozzle 29 and the cleaning agent supply opening 35 are arranged offset from a vertical center plane of the receiving unit 3 (as can be defined in Fig. 1b approximately by the plane E). Fig. 1c shows a schematic representation of the receiving unit 3 of the dosing device 1 with a sketched fluid flow in the manner of a cyclone. The viewing direction is from above ontothe receiving unit 3 is selected, whereby the view into the interior of the receiving unit 3 is at least unobstructed with respect to the fluid flow. Also shown are the particles 37 of the cleaning agent, which are carried along by the cleaning fluid flow on the downward spiral path 33 (and at least partially along the inner surface 25). In the case of a powdery bulk material, the bulk material residues 27 are, for example, swirled up by the cleaning fluid flow and, due to their inertia and / or after the fluid jet has been supplied, settle in the discharge area 13 of the device 1, from where they can be removed from the device 1, for example, by suction. For example, a dust portion can be sucked upwards by the suction device 23, while the cleaning agent falls downwards in the discharge 19 (i.e., along the direction of gravity). Typically, the swirled up or loosened bulk materialdischarged from the device 1 via the discharge opening 17, in particular sucked off. The fluid 43 ejected from the nozzle 39 can be additionally swirled by the discharge element 15, so that the movement of the discharge element 15 additionally supports the cleaning effect of the fluid 43. In addition, the conveying device 1 also has a nozzle 45 for blowing fluid into a coupling area 47, in which the discharge element 15 is connected to a drive element 49 (for example a drive shaft). Bulk material accumulated within the coupling area 47 cannot be displaced by the discharge element 15, and thus remains within the device 1 without additional measures. By blowing fluid 51 into the coupling area 47, bulk material located there can be swirled up and / or discharged, in particular sucked off, from the device 1 via the discharge opening 17, for example. Both theNozzle 39 as well as nozzle 45 is located in a bearing element 53 for supporting the discharge element 15, which also has the coupling area 47. Fig. 1d shows a more detailed schematic representation of the area B of the device 1 marked in Fig. 1a. This shows, in particular, the bearing element 53 together with the coupling area 47 and the nozzle 39 and the nozzle 45. Fig. 2 shows a schematic representation of an alternative embodiment of a conveying device according to the invention. The discharge element 15 shown in Figure 2 shows a conveyor screw with a shaft 16 in the form of a hollow shaft. The hollow shaft has several nozzles 52 which expel a fluid flow 53 in the radial direction towards the shaft 16. The nozzles 52 are arranged at a distance from one another in the main extension direction of the conveyor screw and in the circumferential direction of the shaft 16. Advantageously, the conveyor screw rotates duringthe fluid 53 flows out, so that in a possibly trough-shaped discharge area 13, the area below the conveyor screw is swirled up and blown out. The shaft 16 of the conveyor screw is provided with a connection for the fluid 52 in the bearing or coupling area 47. Fig. 3 shows a schematic representation of a system according to a further aspect of the invention. The system 101 has a conveyor device 103 according to the first aspect of the invention. For example, this is the conveyor device 1 discussed with reference to Figs. 1a-1d. Therefore, the features of the conveyor device 103 are provided with the reference numerals of the conveyor device 1 discussed with reference to Figs. 1a-1d. In addition, the system 101 has an extruder 105. Bulk material from the conveyor device 103 can be fed to the extruder 105 via the vertical discharge. Following the cleaning of the conveyor device 103,In system 101, the cleaning agent is fed to the extruder 105 and used there to rinse the extruder 105. Thus, both reliable cleaning of the conveyor device 103 and rinsing of the extruder 105 are possible in a single operation. The features disclosed in the preceding description, in the drawings, and in the claims can be essential to the invention in its various embodiments, both individually and in any combination.

[0002] List of reference symbols 1 Conveyor device 3 Receiving unit 5 Main opening 7 Cover 9 Bulk material feed opening 11 Bulk material outlet opening 13 Discharge area 15 Discharge element 16 Shaft, hollow shaft 17 Discharge opening 19 Vertical discharge 21 Suction opening 23 Suction device 25 Inner surface 27 Bulk material residues 29 Additional nozzle 31 Fluid jet 33 Spiral track 35 Cleaning agent feed opening 37 Particles 39, 45, 52 Nozzle 41 Dead space 43, 51, 53 Fluid 47 Coupling area 49 Drive element 101 System 103 Conveyor device 105 Extruder B Area E Definable plane X, Y, Z Coordinate axis

Claims

Patent claims 1. Conveying device (1) for bulk material, wherein the device has ‐ at least one receiving unit (3) for receiving bulk material to be dosed, and ‐ at least one discharge area (13), ‐ ‐ which follows the receiving unit (3) in the main conveying direction and / or ‐ ‐ into which bulk material can be displaced from the receiving unit (3), in particular via a bulk material outlet opening (11) of the receiving unit (3), and ‐ ‐ a discharge element (15) provided within the discharge area (13) for discharging the bulk material from the discharge area (13) in the direction of a discharge opening (17) of the device, ‐ wherein at least one nozzle (39, 45, 52) is provided for blowing fluid into an area (13) surrounding the discharge element (15).Conveying device (1) according to claim 1, wherein the nozzle (39, 45, 52) is provided (i) for injecting fluid (51) into a coupling region (47), in which coupling region (47) the discharge element (15) is connected to a drive element (49), such as a drive shaft, or (ii) for injecting fluid (43) into a dead space (41) below the discharge element (15) or (iii) for injecting fluid (53) into the radially existing region between a shaft (16) of the discharge element (15) and an inner surface of a housing forming the discharge region (13).

3. Conveying device (1) according to one of the preceding claims, wherein the nozzle (39, 45) is arranged on or in a bearing element for supporting the discharge element (15), in particular in the coupling region.

4. Conveying device (1) according to one of the preceding claims, wherein the nozzle (52) is arranged on or in a shaft (16) or a hollow shaft of the discharge element (15).

5. Conveying device (1) according to one of the preceding claims, wherein the nozzle (39) can expel the fluid (43) along a direction perpendicular to the direction of gravity or parallel to the main extension direction of the discharge element (15).

6. Conveying device (1) according to one of the preceding claims, wherein the nozzle (45) can expel the fluid (51) along a direction perpendicular to the main extension direction of the discharge element (15) and / or deflect it in a direction parallel to the main extension direction.

7. Conveying device (1) according to one of the preceding claims, wherein the nozzle (52) can expel the fluid (43) along a direction radial to the main extension direction of the discharge element (15). 8.Conveying device (1) according to one of the preceding claims, wherein and at least one further nozzle (29) for at least temporarily ejecting a fluid jet (31) into the receiving unit (3), wherein the further nozzle (29) is aligned such that an inner surface (25) of the receiving unit (3) can be at least partially exposed to the fluid jet (31) for at least partially forming a fluid flow in the manner of a cyclone as a cleaning fluid flow.

9. Conveying device (1) according to one of the preceding claims, wherein the receiving unit (3) has a, in particular removable, cover (7) and preferably a bulk material feed opening (9) is provided in the cover (7) and / or wherein the receiving unit (3) is rotationally symmetrical, in particular at least in some regions.

10. Conveying device (1) according to one of the preceding claims, wherein the receiving unit (3) has, at least in some sections, a diameter, in particular an inner diameter, that tapers along the direction of gravity. 11.Conveying device (1) according to one of the preceding claims, wherein the further nozzle (29) is oriented in such a way, in particular relative to the receiving unit (3) or to the inner surface (25) of the receiving unit (3), that the fluid jet (31) ejected by the further nozzle (29) can be deflected by means of an impact region of the inner surface (25) of the receiving unit (3).

12. Conveying device (1) according to one of the preceding claims, wherein the further nozzle (29) is arranged on the cover (7) of the receiving unit (3), in particular in such a way that, when the cover (7) is closed, the further nozzle (29) protrudes at least partially into the receiving unit (3). 13.Conveying device (1) according to one of the preceding claims, wherein the device comprises a storage container for receiving a cleaning agent, in particular a granular cleaning agent, such as cleaning granules, and / or is connected or connectable to such a storage container.

14. Conveying device (1) according to one of the preceding claims, wherein the device comprises a cleaning agent supply opening for supplying the cleaning agent into the interior of the receiving unit (3). 15.Conveying device (1) according to one of the preceding claims, wherein the discharge opening (17) opens into a discharge element (19), wherein (i) bulk material can be discharged from the conveying device (1) via the discharge element (19) in a direction parallel or inclined to the direction of gravity and / or (ii) the discharge element (19) has a suction opening (21) for suctioning off a fine fraction and / or the suction opening (21) and / or the discharge opening (17) is or can be operatively connected to a suction device (23) for suctioning off dust.System comprising a conveying device (1) according to one of the preceding claims and at least one extruder (105), wherein (i) the extruder (105) is provided downstream of the device, in particular the receiving unit (3), the discharge opening (17) and / or the discharge element (19), in the main conveying direction, and / or (ii) bulk material from the conveying device (1) can be fed, in particular in a metered manner, to the extruder (105), in particular via the discharge element (19).Method for cleaning a conveying device (1), in particular a conveying device (1) according to one of claims 1 to 15, wherein - at least parts of residues of bulk material deposited and / or adhering to an inner surface of the receiving unit (3) or the discharge area (13) are detached - and / or conveyed in the direction of the discharge opening (17), - by forming a fluid flow as a cleaning fluid flow at least in some areas within the discharge area (13), the receiving unit (3) and / or a coupling area (47) of the discharge element (15).

18. Method according to claim 17, wherein residues of bulk material, in particular from dead spaces, in the discharge area (13) are detached by the fluid flow.

19. The method according to claim 17 or 18, wherein (i) the cleaning fluid flow is formed in the manner of a cyclone; (ii) the fluid flow is introduced into the receiving unit (3) by a fluid jet (31) ejected from a further nozzle (29), and wherein preferably the fluid jet (31) is directed obliquely against an inner surface (25) of the receiving unit (3) and preferably a deflection of the fluid flow in a circumferential direction of the receiving unit (3) is carried out at least partially; (iii) by an interaction between the fluid jet (31) and / or the fluid flow and the inner surface (25) of the receiving unit (3) within at least parts of the receiving unit (3), a fluid flow in the manner of a cyclone is formed;(iv) a cleaning agent, in particular a granular cleaning agent, such as cleaning granules, is supplied to the fluid flow, which is preferably transported by the fluid flow at least temporarily and / or at least partially along the inner surface (25) of the receiving unit (3), and in particular residues of bulk material are detached from the inner surface (25); (v) the cleaning agent is supplied to the fluid flow after stable formation of the cyclone; (vi) the cleaning agent and a fine fraction are separated from one another after exiting the conveying device (1), in particular by suctioning off the fine fraction and / or by ejecting the cleaning granules parallel or inclined to the direction of gravity;and / or (vii) an extruder (105) following the conveying device in the main conveying direction is rinsed with the cleaning agent emerging from the conveying device (1), in particular by guiding the cleaning agent emerging from the conveying device (1) through the extruder (105).

20. Method according to one of claims 17 to 19, wherein control of the bulk material feed opening (9), the discharge element (15) of the conveying device (1), the nozzles (39, 45, 52), the further nozzle (29), the cleaning agent feed device (35), the extruder (105) and / or the suction device (23) is provided in a defined temporal sequence. ;

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