Abstract:
The invention relates to a device for conveying a fine-particle medium, in particular a granulate, including a flexible receptacle for receiving the medium, a receiving fixture for fastening of the receptacle in the region of an upper end facing away from a base of the receptacle, and a suction apparatus, inserted from above into the receptacle, for sucking the medium out of the receptacle. The device further includes outside the receptacle, in its base region or its lateral region, an apparatus for acting on the receptacle for the purpose of its deformation. The device ensures that feed interruptions during the conveyance of the fine-particle medium are avoided so that the medium is kept in a conveyable state, whereby an undisturbed automated feed of the medium is secured.

Description:
CROSS REFERENCE TO RELATED APPLICATION 
       [0001]    This application claims the benefit of foreign priority to European Patent Application No. EP 14 165 715.5 entitled “Einrichtung zum Fördern eines feinteiligen Mediums” filed on Apr. 24, 2014, the entire disclosure of which is incorporated herein by reference. 
       FIELD OF THE INVENTION 
       [0002]    The invention relates to a device for conveying a fine-particle medium, in particular a granulate, comprising a flexible receptacle for receiving the medium, a receiving fixture for fastening of the flexible receptacle in the region of an upper end facing away from a base of the flexible receptacle, and a suction apparatus, inserted from above into the flexible receptacle, for sucking the medium out of the flexible receptacle. 
       BACKGROUND OF THE INVENTION AND RELATED ART  
       [0003]    Devices for conveying a fine-particle medium, for instance a medium which is in the form of a granulate or in powder form, are well known from the prior art. 
         [0004]    A market-standard form of delivery of hotmelt for packaging applications is granulate. This can be fed from a receptacle to a further processing unit, for instance a melting unit. Granulates of such a type are inclined to wedge in a storage tank or intermediate storage tank, to clog, to form cavities or, depending on their chemical formulation, to stick together or bond together. Consequently, the onward feed of the granulate into a connected further processing unit is interrupted or disturbed. 
         [0005]    A device of the type stated in the introduction is known from DE 20 2010 006 010 U1. This has a suction apparatus, disposed within the flexible receptacle, with vibration unit. The vibration unit consists of a plurality of vibration elements. These achieve a loosening effect, in the region of the vibration unit, of the medium received by the receptacle. According to a first variant, the vibration unit is disposed only in a central region of the receptacle and is therefore of compact and structurally relatively simple design. As a result of this configuration and arrangement of the vibration unit, clogging of the medium in the region of the side walls of the receptacle cannot be prevented. According to a second variant, it is provided that the vibration unit extends over the entire cross section of the receptacle. Since the vibration unit reaches to the side walls of the receptacle, this design prevents clogging to be attained over the entire cross section of the receptacle. However, the structural complexity for the vibration unit is very high. Because of its size, moreover, the vibration unit has a high weight, so that the total mass of the mobile suction apparatus with vibration unit is very high. 
         [0006]    In EP 2 612 817 A1, a flexible receptacle having a material discharge funnel disposed in the region of the base of the receptacle is known. The funnel is provided with lateral receiving apparatuses for transmitting a vibration generated outside the funnel into the interior of the receptacle. The material of the funnel is selected such that a phase shift or amplitude shift between internal and external vibration is achieved, which shift prevents clogging/adhesion of the fine-particle medium on/to the funnel. 
         [0007]    In EP 1 544 132 A2, a receptacle for receiving pellets or similarly sized items is described, wherein the storage receptacle is provided with movable, plate-like side walls. Through mechanical adjustment of the pitch of the side walls by means of a winch and the therewith associated volume reduction of the storage receptacle, the material delivery into a discharge apparatus, for example a worm, is ensured. During emptying of the receptacle prior to refilling, the receptacle volume must be mechanically enlarged again by resetting of the side walls. 
         [0008]    From U.S. Pat. No. 2,829,803, a receptacle having mechanically adjustable side walls is likewise known. 
       OBJECT AND SUMMARY OF THE INVENTION 
       [0009]    The object of the present invention is to refine a device of the type stated in the introduction such that an undisturbed automated feed of the fine-particle medium is secured, thus feed interruptions are avoided and the medium is kept in a conveyable state. Moreover, the device is intended to be of a structurally particularly simple design. 
         [0010]    The object is achieved by virtue of the fact that, outside the flexible receptacle, in its base region or its lateral region, is arranged an apparatus for acting on the flexible receptacle for the purpose of its deformation. 
         [0011]    In the device according to the invention, it is of fundamental importance that the fine-particle medium present in the flexible receptacle, in particular the granulate present in the flexible receptacle, is sucked upward out of the flexible receptacle by means of the suction apparatus inserted in the flexible receptacle. The problem thus arises that, in particular the medium present in the lower region, thus in the region of the base, and in the region of the side walls of the flexible receptacle, due to the weight of the medium present in the filled flexible receptacle, wedges, clogs, forms cavities, or, moreover, depending on the chemical formulation, sticks together or bonds together. Also in this lower region of the flexible receptacle and in the region of its side walls, it is necessary to ensure that the conveyable state of the medium is maintained so as to enable this to be sucked upward out of the flexible receptacle by means of the suction apparatus. The problem thus appears differently than that in a receptacle which has in the base region a discharge opening for the medium. The fact that, according to the invention, the apparatus for acting on the flexible receptacle for the purpose of its deformation is disposed outside the flexible receptacle, and this apparatus acts on the flexible receptacle in the base region or the lateral region of thereof, means that the fine-particle medium can be kept in the conveyable state in an extremely simple manner and, furthermore, with minimal structural complexity. To this end, it is merely necessary to act on the flexible receptacle by means of the apparatus at certain intervals, whereby the apparatus deforms the receptacle and thus acts on the medium, so that no wedging, clogging or sticking/bonding together can occur, nor can cavities be formed within the medium. 
         [0012]    Preferably, the apparatus for acting on the flexible receptacle has a means for periodically acting on the receptacle. 
         [0013]    Preferably, the apparatus for acting on the flexible receptacle has a means for acting percussively on this receptacle, or a means for moving the base of the receptacle. In particular, it is provided that the means moves back and forth together with the base of the flexible receptacle. The movement is made with an acceleration which, when a top or bottom dead center of the means is reached, causes the material structure of the medium contained in the flexible receptacle to be abruptly altered. 
         [0014]    The flexible receptacle consists, in particular, of a fabric, cloth, plastic, or some other flexible material. It is here important for the receptacle to be flexible in order that it deforms when acted on by means of the apparatus. The change of shape of the receptacle results in the settled, wedged, bonded, clogged fine-particle medium, in particular granulate, which can no longer, or only with difficulty, be conveyed, being loosened again. Preferably, the means for acting on the flexible receptacle moves back and forth together with the base of the receptacle, whereby the change in position of the means for acting on the receptacle proceeds simultaneously with the change in position of the receptacle in its base region, since the means and the receptacle are in constant contact. As a result of either the bottom or top dead center of the means having abruptly been reached, the medium present in the flexible receptacle is likewise abruptly stopped and thus the material structure or the bridging of the medium is altered. As a result of the occurring sudden mass stoppage of the flexible receptacle and the medium present therein, the material structure of the medium is altered such that the medium is set into a free-flowing state or this state is maintained. After this, the medium is conveyed out of the receptacle, in an upwardly directed material flow direction, by means of the suction apparatus. 
         [0015]    According to a preferred refinement of the invention, it is provided that the apparatus for acting on the flexible receptacle has a lifting unit and the means which is movable back and forth from this and is configured as a plate, wherein the plate can be brought into contact with the base of the receptacle or the receptacle rests on the plate. As a result of this configuration, an impact force can be transmitted to the receptacle over a large area. 
         [0016]    In particular, it is provided that the apparatus for acting on the receptacle is disposed beneath the flexible receptacle. This produces a favorable force application point of the apparatus for acting on the receptacle, such that, as a result of this, an impact force can be applied to the receptacle in the vertical direction. Furthermore, the arrangement of the apparatus for acting on the receptacle beneath the receptacle enables a compact overall layout. 
         [0017]    The flexible receptacle is preferably secured, in the region of its upper end, in the receiving fixture. The fastened receptacle is thus fixed in the region of its upper end, whereby the receptacle, when a force acts on the base from below, is not raised in its entirety. 
         [0018]    According to a preferred refinement of the invention, it is provided that the device for conveying the fine-particle medium has a stable container, which receives the receptacle in its interior. In particular, the container is configured in the style or form of a commercially available waste receptacle with container bottom part and container lid mounted pivotally in said container bottom part. Such a waste receptacle is, in particular, a waste receptacle as used in households, which has a capacity, for instance, of 240 liters. In the style of such a waste receptacle, the container has, for instance, two wheels for transport of the container in its slightly tilted position. The container is of substantially cuboid design, with upper opening and the container lid for closing this opening in the container bottom part. 
         [0019]    Preferably, the receptacle is clamped, in the region of its upper end, between the container bottom part and the container lid fixedly connected thereto. Since the container, concretely the container bottom part, is firmly closed by means of the container lid, lifting of the flexible receptacle out of the container by means of the apparatus for acting on the receptacle or by means of the lifting unit is in this way prevented. The container lid thus forms a type of stop or fixed point for the flexible receptacle, whereby the container lid compels a change of shape of the flexible receptacle in the upper side region as a result of the lifting movement. This stop ensures the reliable desired change of shape of the receptacle. 
         [0020]    Preferably, the apparatus for acting on the receptacle within the container is thus disposed beneath the receptacle. Thus a particularly compact design of flexible receptacle and apparatus for acting on the receptacle, in association with the container receiving these components, can be obtained. 
         [0021]    The flexible receptacle is in total or in part, at least in the region of side walls of the receptacle, flexibly configured. 
         [0022]    In one embodiment, the flexible receptacle is preferably of the kind in which the fine-particle medium is delivered. 
         [0023]    The container preferably consists of plastic or metal. In principle, different cross-sectional shapes of container and/or flexible receptacle can be used, for instance a round or oval cross-sectional shape. 
         [0024]    The apparatus for acting on the flexible receptacle or the lifting unit can be driven in different manner, in particular pneumatically, electrically, hydraulically. The movement thereof can be vertical, from below, or horizontally, from the side, thus lateral impacting on the flexible receptacle. Of particular advantage is a shaking movement on the flexible receptacle. The lifting unit can contain a lifting plate apparatus consisting of a plurality of segments which rise and fall simultaneously or at intervals. The plate of the lifting unit and the base of the flexible receptacle can permanently touch, or have at least in part a different acceleration. Consequently, the plate impacts on the receptacle or the receptacle falls onto the plate. 
         [0025]    In the configuration of the container with the container lid, it is in particular provided that the container lid has an opening which passes through a lance of the suction apparatus. Since the fill state of the flexible receptacle changes with increasing emptying, it is provided that the suction apparatus follows the fill state of the receptacle. From this point of view, the suction apparatus or the lance of the suction apparatus passes, axially guided, through the container lid. This guidance enables a motional play of the suction apparatus or of the suction lance within a defined range and prevents catching of the suction apparatus or of the suction lance on the container lid. Such catching would result in the suction apparatus or the suction lance being unable to suck up any medium due to the suction apparatus or the suction lance hanging in the air. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWING FIGURES  
         [0026]    In the drawing figures, the invention is represented with reference to a preferred illustrative embodiment without being restricted thereto, wherein like reference characters refer to the same or similar parts, items, assemblies or subassemblies in the various views. 
           [0027]      FIG. 1  shows a vertical section through a device for conveying a fine-particle medium, with a filled flexible receptacle, according to an exemplary embodiment of the present invention. 
           [0028]      FIG. 2  shows a circuit diagram for illustrating the driving of the apparatus for acting on the receptacle and driving of the suction apparatus. 
       
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
       [0029]    The device, illustrated in  FIG. 1 , for conveying the fine-particle medium is denoted generically by the reference numeral  1 . This fine-particle medium is in the form, for instance, of a granulate, which is to be fed to a further processing unit, for instance a melting unit. The market-standard form of delivery for hotmelt for packaging applications is granulate. 
         [0030]    The device  1  has a stable container  2 , which receives in its interior  3  a flexible receptacle  4  which likewise forming a component part of the device  1 . The container  2  is configured in the style of a commercially available waste receptacle having a capacity of 240 liters and hence has a container bottom part  5  and a container lid  7  mounted pivotally therein about an axis  6 . The container  2  consists of plastic and is of largely thin-walled configuration. The internal cross section of the container bottom part  5 , thus the cross section of the interior  3 , is square. 
         [0031]    The flexible receptacle  4  consists, for instance, of a fabric and is thus flexible in its entirety. In the region of the upper end, the receptacle  4  is suspended. In this respect, the container top part  5  has in the region of its upper end a circumferential horizontal portion  8 , by which the receptacle  4  is suspended with its upper rim  9 , which rim is directed downward in a U-shape. For reasons of clarity, the rim  9  is not resting on the portion  8 , but is illustrated arranged at a distance above this. In reality, the receptacle  4  rests in the region of the U-shaped rim  9  on the portion  8  of the container bottom part  5 . 
         [0032]    The flexible receptacle  4  is filled with the fine-particle medium  10 , in the present case granulate. The fill level of the granulate  10  is illustrated with the reference numeral  11 . Accordingly, the receptacle  4  is almost completely filled. 
         [0033]    Into the flexible receptacle  4 , which is open at the top, a suction apparatus  12  is inserted from above. The container lid  7  has an opening  13 , which passes through a lance  14  of the suction apparatus  12 , wherein this lance  14  is axially guided by means of a guide  15  mounted in the container lid  8 . The lance  14 , in the region of which is arranged a suction opening  16  for the medium  10 , is inserted in the receptacle  4  to the point where the lance  14  is disposed adjacent to a base  17  of the receptacle  4 . 
         [0034]    During operation of the device  1 , contrary to the representation in  FIG. 1 , the container lid  5  is disposed in its closed position, whereby it is horizontally positioned and rests on the rim  9  of the container bottom part  5 . In this position, the container lid  7  is locked in place on the container bottom part  5 , so that the container lid  7  cannot be inadvertently opened. Between the container lid  7  and the container bottom part  5 , the flexible receptacle  4  is clamped in the region of its rim  9 , and thus secured. 
         [0035]    The container  2  rests on a ground surface or on a standing surface  18 . The container bottom part  5 , for its part, has a base  19 . On this is arranged an apparatus  20  for acting on the receptacle  4  for the purpose of its deformation. The apparatus  20  can be fastened to the base  19 . The apparatus  20  has a means  21 , configured as a rigid plate, for acting on the receptacle  4 . The plate  21  here has a cross section parallel to the base  19  of the container bottom part  5  which is slightly smaller than the cross section of the container bottom part  5 . The apparatus  20  further has a lifting unit  22 , mounted in the base  19  of the container bottom part  5 , for lifting and lowering the plate  21 . A lifting rod  23  of the lifting unit  22  is here fixedly connected to the plate  21 . The lifting motional directions of the lifting rod  23 , and thus of the plate  21 , are illustrated by the double arrow  24 . 
         [0036]    The arrow  25  illustrates the direction of conveyance of the medium or granulate  10  through the lance  14 . 
         [0037]    In the container bottom part  5  is hung, in the region of the portion  8 , a receiving apparatus  26 , which serves for the mounting of a control unit  27 . 
         [0038]    When the flexible receptacle  4 , in particular a receptacle  4  filled with medium or granulate  10 , is inserted in the container  2 , the base  7  of the receptacle  4  rests on the plate  21  of the apparatus  20  for acting on the receptacle  4 . The length of the flexible receptacle  4  in the flow direction of the medium is here greater than the distance between the top edge of the means  21  and the portion  8 . If the plate  21  is raised from the lowered position illustrated in  FIG. 1 , this leads to a deformation of the receptacle  4  in the region of its side walls  28 , and thus of the medium or granulate  10  received by the receptacle  4 . Should the medium present in the receptacle  4  have become wedged or clogged, or stick together or bond together, depending on its chemical formulation, this wedging, clogging, sticking or bonding together can be dispelled by repeated lifting and lowering of the plate  21 , and thus repeated action of the plate  21  on the receptacle  4 , as a result of its repeated variable deformation of the receptacle  4 , so that the medium or granulate  10  in the free-flowing state is sucked out of the receptacle  4  by means of the suction apparatus  12  and can be fed in an automated and uninterrupted manner to a further processing unit. 
         [0039]    Instead of the direct contact of plate  21  and flexible receptacle  4 , whereby the base  17  of the receptacle moves periodically with the plate  21 , it can well be provided that the lifting unit  22  impacts obliquely from below periodically against the receptacle  4 . In principle, in the deformation of the receptacle  4 , owing to the flexibility of the receptacle  4 , and due to the change of position of the plate  21  between its lower and upper lifting position, at least a section of the side walls  28  of the flexible receptacle  4  is mechanically deformed. The change of shape of the receptacle  4  results in the settled, wedged, bonded, clogged granulate, which can no longer, or only with difficulty, be conveyed, being loosened again. This desired effect is obtained in that the lifting unit, in one embodiment, lowers itself faster than the flexible receptacle, with the granulate  10  present therein, can fall back into the bottommost position under its own inertia. Another embodiment describes the change of position of the plate  21 , which proceeds simultaneously with the change of position of the base  17  of the flexible receptacle  4 , since these are in constant contact. As a result of either the bottom or top dead center having abruptly been reached, the granulate  10  present in the receptacle  4  is likewise abruptly stopped and thus the material structure or the bridging of the granulate  10  is altered. As a result of the, in both cases, sudden mass stoppage of the receptacle  4  and the granulate  10  present therein, the material structure of the granulate  10  or of the bulk material is altered such that the granulate is set into a free-flowing state or this state is maintained. After this, the granulate  10  is conveyed out of the receptacle  4 , in an upwardly directed material flow direction  25 , by means of the suction lance  14 . 
         [0040]    Since the primarily vertical movement of the plate  21  transmits a primarily vertical movement to the lance  14 , the guide  15  for the lance  14  is provided on the closed container lid  7 . This guide  15  enables a motional play within a defined range and prevents catching of the lance  14 , inter alia, on the container lid  7 . This catching, in turn, would result in the lance  14  being unable to suck up any granulate  10  due to the intake part of the suction lance  14  hanging in the air. Since the container  2  is closed by means of the container lid  7 , lifting of the receptacle  4  out of the container  2  by means of the lifting unit  22  is prevented. The container lid  7  thus forms a type of stop or fixed point for the flexible receptacle  4 , which compels a change of shape of the flexible receptacle  4  in the upper side region as a result of the lifting movement. As a result of this stop, a particularly reliable, desired change of shape of the receptacle  4  is ensured. 
         [0041]    A switching arrangement for the substantially pneumatic operation of the device  1  is illustrated in the circuit diagram according to  FIG. 2 . 
         [0042]    Shown is a compressed air source  29  having a pressure level of, for instance, 6 bar, a 2/2-way manual shutoff valve  30 , a 2/2-way electromagnetic valve  31 , a pressure regulator with manometer  32 , the suction lance  14 , a 5/2-way valve  33  (with control air), a pressure tank  34 , a rapid action vent valve  35 , and a pneumatic cylinder  36  of the lifting unit  22 , wherein the piston rod of the pneumatic cylinder  36  forms the lifting rod  23  of the lifting unit  22 . Illustrated is that, when the valves  30  and  31  are in an open position, the suction lance  14  is supplied with compressed air for the suction and conveyance of the granulate  10  and, depending on the switch position of the valve  33 , the pneumatic cylinder  36  is acted on in such a way that the lifting rod  23 , and thus the plate  21 , is raised or lowered.