Abstract:
A method of tranporting pulverulent filling material through at least one line. The method comprises opening a chamber-like line region located in the at least one line, introducing the pulverulent filling material into the chamber-like line region, closing the chamber-like line region, and pressing the pulverulent filling material out of the chamber-like line region and at least partially into the at least one line using at least one compressed air pulse.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS  
       [0001]     This application claims the priority of German Patent Application No. 10 2005 006 601.1, filed Feb. 11, 2005, the entire content of which is incorporated herein by reference. The disclosures of all U.S. and foreign patents and patent applications mentioned below are also incorporated herein by reference.  
       BACKGROUND OF THE INVENTION  
       [0002]     The present invention relates to a method for transportation of pulverulent filling material through a line, and in particular, micronized filling material. The invention also relates to a device for carrying out the method.  
         [0003]     Pulverulent filling materials may be foodstuffs and luxury items, such as, for example, coffee powder, cocoa powder, and the like. Alternatively, the filling material may be a pharmaceutical, in which case the filling material may contain very small nonflowable pulverized particles, or consist solely of such. In particular, powders used as pharmaceuticals are commonly taken by the patient in the form of what is known as “micronized powder” in very small quantities of 2 to 20 mg (milligrams). Such micronized powders commonly have a particle size of between 0.5 micrometers and 5.0 micrometers and below. Such powders can agglomerate to a very great extent, so that, in technical terms, they cannot be transported and introduced into containers in a simple manner.  
         [0004]     German patent document DE 102 47 829 A1 discloses a method and device for the pneumatic conveyance of pulverulent material through a line. The pulverulent material is acted upon alternately by underpressure and overpressure, and is thus alternately sucked into and pressed out of a line section. Action by gas underpressure and gas overpressure requires a filter element. The finer the pulverulent material is, the more quickly such filter elements clog up. In order to maintain the performance and continuity of the powder transport through the line, the overpressure has to be increased continuously in response to the clogging of the filter element. An attempt is made to reduce the degree of contamination of the filter element (and thereby lengthen its useful life) by designing the filter element in such a way that it surrounds, as a hollow cylinder, the section of the line acted upon by the underpressure and overpressure.  
         [0005]     Filling devices, such as the types known from German patent documents DE 202 09 156 U1 and DE 102 26 989 A1, are commonly supplied with such pulverulent filling material through lines of this type. Pulverulent filling material is introduced from the filling devices into individual containers in predetermined metered quantities. An interruption in the operation of such filling devices, such as may occur, for example, during cleaning work on the above-mentioned filter element which is no longer sufficiently gas-permeable, is highly undesirable.  
       SUMMARY OF THE INVENTION  
       [0006]     It is an object of the invention to provide a method of supplying pulverulent filling material to filling devices of the above-mentioned type that is as reliable as possible, and at the same time, is as economical as possible.  
         [0007]     According to one exemplary embodiment of the present invention, a method of transporting pulverulent filling material through at least one line comprises: opening a chamber-like line region located in the at least one line; introducing the pulverulent filling material into the chamber-like line region; closing the chamber-like line region; and pressing the pulverulent filling material out of the chamber-like line region and at least partially into the at least one line using at least one compressed air pulse.  
         [0008]     Another exemplary embodiment of the present invention relates to an apparatus for transporting pulverulent filling material. The apparatus comprises: a storage vessel including at least one exit; a chamber-like line region constituting a powder chamber located at the at least one exit of the storage vessel; a line connected to the chamber-like line region, through which a portion of the pulverulent filling material present in the chamber-like line region is transported out of the chamber-like line region; a compressed air duct that issues into the chamber-like line region; and a closing device for the chamber-like line region, the closing device adapted to close the chamber-like line region powder tight with respect to the storage vessel.  
         [0009]     One advantage of the present invention is that no gas-permeable filter elements are required in order to transport the pulverulent filling material. More specifically, the transport of the pulverulent filling material through a line can be implemented solely by gas pressure pulses, such as, for example, air pressure pulses. According to an exemplary embodiment, a chamber-like line region is formed in the line through which pulverulent filling material is to be transported. The chamber-like line region can be opened and pulverulent filling material can be introduced into the chamber-like line region. Subsequently, the chamber-like line region can be closed, and then the introduced filling material can be pressed out of the chamber-like line region and at least a little way into the line by means of at least one compressed air pulse. Additional filling material can then be introduced into the then completely or partially emptied chamber-like line region, and pressed out of the chamber-like line region and a little way into the line in a similar manner. This operation can be repeated intermittently, with the result that filling material portions lying at a greater or lesser distance one behind the other in the line are pressed through the line. At the region of issue of the line, the pulverulent filling material falls, for example, into the storage container of the respective metering device present near the filling device.  
         [0010]     The filling of the chamber-like line region may take place from a powder storage vessel. The powder storage vessel may be positioned, for example, with its outlet present in the bottom region in relation to the chamber-like line region in such a way that powder can flow out of the storage vessel and into the chamber-like line region. Subsequently, the chamber-like line region can be closed, and the pulverulent filling material can be pressed out of the line region and into the line by means of one or more compressed air pulses, as described above.  
         [0011]     The filling material present in the storage vessel may be loosened continuously or intermittently, in order to avoid the formation of material bridges within the storage vessel.  
         [0012]     It has proved advantageous to arrange in the storage vessel a scraping element, by means of which pulverulent filling material can be scraped, that is to say pushed, into the chamber-like line region. The scraping element may at the same time be used in order to close the chamber-like line region. Insofar as the continuously or intermittently driven scraper is located in the region of the orifice of the chamber-like Line region, it may serve as a closure for this line region. During the further movement of the scraper, the latter then releases the orifice, so that a following or the same scraper can again push pulverulent filling material into the line region.  
         [0013]     Details relating to the design of the apparatus according to the invention, by means of which the above-described method according to the invention can be carried out, are illustrated in the drawings. It may be advantageous for a plurality of the lines through which pulverulent filling material is transported to end in a single storage vessel. Pulverulent filling material can thereby be transported out of a single storage vessel through a plurality of lines to a plurality of filling devices. The plurality of outlets of the storage vessel may be arranged in the bottom region of the latter and preferably such that the individual orifices of the various lines can be opened and closed successively, or even simultaneously, by means of one scraper moving, for example, rotating, back and forth. The scraper may correspondingly possess a plurality of scraping arms which, on the one hand, push filling material into the individual chamber-like line regions and, on the other hand, close the respective line regions once these have been filled with filling material. As illustrated by way of example in the drawings, this may effectively be made possible in a simple way in technical terms by means of a rotating scraper having a corresponding number of scraping arms.  
         [0014]     An agitating device may be provided in the storage vessel in order to avoid bridge formation by the filling material in the storage vessel. This agitator device may be fixedly connected to the scraper in structural terms, so that, during, for example, a rotating movement of the agitator, the scraper also rotates.  
         [0015]     The gas, such as, for example, the air pressure pulse required for transporting the individual filling material quantities may be set, as desired, in its pulse length and, independently of this, also in its pressure intensity. In the case of the filter element known in the prior art, which is acted upon alternately by underpressure and by overpressure, and in which the pressure pulse is also utilized for cleaning off the filter element, a specific pressure intensity cannot be undershot. In the present case, this restriction is absent because there is no filter element.  
         [0016]     Further refinements and advantages of the invention may be gathered from the features also listed in the claims and from the exemplary embodiment illustrated in the drawings. 
     
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0017]     The invention is described and explained in more detail below with reference to the exemplary embodiments illustrated in the drawings, in which:  
         [0018]      FIG. 1  is a cross-sectional view through a storage vessel according to the invention with open bottom outlets, taken along line  1 - 1  of  FIG. 2 ,  
         [0019]      FIG. 2  is a cross-sectional view through the bottom region of the storage vessel of  FIG. 1 , taken along line  2 - 2  of  FIG. 1 ,  
         [0020]      FIG. 3  is a cross-sectional view similar to that of  FIG. 1 , shown with closed bottom outlets,  
         [0021]      FIG. 4  is a cross-sectional view through the bottom region of the storage vessel of  FIG. 3 , taken along line  4 - 4  of  FIG. 3 ,  
         [0022]      FIG. 5  is a longitudinal cross-section through an exemplary storage vessel according to the present invention, pivoted through  1800  and docked at a powder container,  
         [0023]      FIG. 6  shows the storage vessel of  FIG. 5 , which, together with the powder container, is pivoted back upward again through 180°, and which is filled with powder out of the powder container,  
         [0024]      FIG. 7  is a cross-sectional view similar to  FIG. 1 , of another exemplary storage vessel according to the present invention, taken along line  7 - 7  of  FIG. 8 , and  
         [0025]      FIG. 8  is a cross-sectional view through the bottom region of the storage vessel of  FIG. 7 , taken along line  8 - 8  of  FIG. 7 . 
     
    
     DETAILED DESCRIPTION OF THE INVENTION  
       [0026]     Referring to  FIG. 1 , pulverulent filling material  12  is present in a storage vessel  10 . The storage vessel  10  can narrow conically downward. In the exemplary embodiment shown, the storage vessel  10  can be closed by means of a cover  14  when it is oriented as shown in  FIG. 1 . Alternatively, the cover  14  can be omitted.  
         [0027]     Six lines  18  can be distributed around the circumference of the bottom  16  of the storage vessel  10 . In the exemplary embodiment shown, the lines  18  are arranged in a star-shaped manner. According to an alternative embodiment, more or less than six lines  18  can be arranged on the storage vessel  10 .  
         [0028]     Each of the lines  18  can end in a chamber-like line region  20  below the bottom  16 . This chamber-like line region  20  can include an orifice  22  directed upward toward the storage vessel  10 . The orifice  22  can communicate with an orifice  24  of approximately the same size in the bottom  16 . The pulverulent filling material  12  present in the storage vessel  10  can fall through the orifice  24  of the bottom  16  and through the orifice  22  in the line  18  into the chamber-like line region  20  of the line  18  from the top downward. This applies to each of the lines  18 .  
         [0029]     The chamber-like line region  20  can constitute an upwardly open powder chamber. The filling of the chamber-like line region  20  can take place by means of a scraper  28 . The scraper  28 , in the exemplary embodiment sh own, includes a plurality of scraping arms  30  (see  FIG. 2 ) which rotate over the bottom  16  in a plane parallel to the bottom  16  and at a very short distance from the bottom  16 . The scraping arms  30  can push pulverulent filling materials  12  in the direction of rotation  32  (see  FIG. 2 ) into the corresponding line region  20 , by means of their longitudinal sides  36 . During the further rotation of the respective scraper  28  in the direction of rotation  32 , the respective scraping arm  30  can close an orifice  24  in the bottom  16 . The orifice  22  in the chamber-like line region  20  is thereby also closed. The scraper  28  can alternatively include only one scraping arm.  
         [0030]     Compressed air can be pressed into the line region  20  from outside through a compressed air duct  40  issuing into the rear bottom region of the chamber-like line region  20 . The filling material  12  present in the line region  20  can thus be pressed out of the chamber-like line region  20  and at least partially into the line  18 . A compressed air pulse is delivered through the compressed air duct  40  only when the scraping arm  30  closes the orifice  24 , that is to say, when the chamber-like line region  20  is closed in the direction toward the supply vessel  10 . The chamber-like line region  20  can comprise a bag-like end of the respective line  18 .  
         [0031]     A shaft  46  can pass through the storage vessel  10  substantially centrally and substantially vertically (when viewed in the orientation shown in  FIG. 1 ). The shaft  46  can be driven in the direction of rotation  32  via a motor drive, not illustrated. The shaft  46  can have a hub  48  fixed to it in terms of rotation. As shown in  FIG. 1 , the hub  48  can be located in the bottom region of the storage vessel  10 . In the exemplary embodiment shown in  FIG. 2 , the six scraping arms  30  project radially from the hub  48 . An agitator  50  can adjoin the top of the hub  48 . The agitator  50  can be fixed to the shaft  46  in terms of rotation. The agitator  50  can include longitudinal bars  54 , which are arranged parallel to the outer wall  52  of the storage vessel  10 . The longitudinal bars  54  can be arranged at a distance from one another. Transverse bars  56  can connect the longitudinal bars  54  to a sleeve-shaped carrying member  58  which can be fixed in terms of rotation to the hub  48 . Diagonal holding bars  60  can also be provided in the upper region. Consequently, the agitator  50  can have a basket-like configuration.  
         [0032]     During rotation of the shaft  46 , the agitator  50 , together with longitudinal bars  54 , transverse bars  56 , and upper holding bars  60 , can move in the direction of rotation  32 , and thereby loosen the pulverulent filling material  12  present inside the storage vessel  10 . At the same time, during this rotational movement of the agitator  50 , the scraping arms  30  can also move jointly in the direction of rotation  32 , causing powder to move into the region of the bottom orifices  24 . To the extent the chamber-like line region  20  present under the respective bottom orifice  24  is empty, this line region  20  is thus re-filled with powder. To the extent that powder is still present in the chamber-like line region (e.g., because the powder has not been emptied out of the line region  20  by means of one more compressed air pulses), the scraping arm  30  sweeps over the orifice  24  without powder being introduced into the line region  20 .  
         [0033]      FIGS. 3 and 4  illustrate the state in which the six scraping arms  30  are all simultaneously aligned above the corresponding six orifices  24 . In this position, the chamber-like line regions  20  can be emptied.  
         [0034]     Once substantially all of the pulverulent filling material  12  has been transported out of the storage vessel  10  through the lines  18  and the storage vessel  10  is consequently empty, the storage vessel  10  can be pivoted through an angle of 180° about an axis  66 , as shown in  FIGS. 5 and 6 . In the exemplary embodiment shown, the axis  66  is substantially horizontal, however alternative configurations are possible. Once inverted, the cover  14  of the storage vessel  10  can be removed, or has previously been removed. A powder container  70  which contains pulverulent filling material  12  and from which the upper cover has been removed can then be docked from below onto the storage vessel  10  ( FIG. 5 ). Subsequently, the storage vessel  10 , together with the docked powder container  70 , can be pivoted upward through 180° again. The storage vessel  10  is then again in its position illustrated in  FIGS. 1 and 3 . The pulverulent filling material  12  present in the powder container  70  can then fall downward out of the powder container  70  into the storage vessel  10 . As soon as the powder container  70  is empty, it can be removed from the storage vessel  10  and the storage vessel  10  closed again by means of the cover  14 . Alternatively, the powder container  70  could remain on the storage vessel  10 , so that the cover  14  could be dispensed with. During the aforementioned refilling of the storage vessel  10  with pulverulent filling material  12 , substantially no pulverulent filling material  12  is transported away from the storage vessel  10  through the lines  18 . This does not impede the work of the filling device connected to the lines  18 , since the metering devices present near the filling devices have in each case their own small stores for the pulverulent filling material  12 . The lines  18  connected to the storage vessel  10  end in these stores which belong to the prior art and are not illustrated in the drawings.  
         [0035]     The pressure pulses can be controlled in terms of their pulse length and/or their pressure intensity in the chamber-like line regions of the lines  18 , through monitoring of the fill level of the filling material still present in the respective stores. Accordingly, only the chamber-like line regions  20  that are connected to lines  18  issuing into stores that need to be filled with pulverulent filling material are emptied by means of one or more pressure pulses.  
         [0036]     Referring to  FIG. 3 , three portions  12 . 3  of pulverulent filling material  12  are illustrated in line  18  located on the right-hand side of the figure. Each of these portions  12 . 3  can correspond to the quantity of pulverulent filling material pressed out of a chamber-like region  20  by means of a compressed air pulse. The pulverulent filling material  12  or the portion  12 . 3  is in each case pressed only a little way into the line  18  and pressed further on. The emptying operation can take place several times in succession, so that portions  12 . 3  are arranged in succession, like beads on a chain, in the line  18 . In each case, the most-recent portion  12 . 3  to enter the line  18  pushes the front portions  12 . 3  through the line  18 . The individual portions  12 . 3  leave the line in succession at its other end, not illustrated in the drawing.  
         [0037]     The storage vessel  10 . 7  illustrated in  FIGS. 7 and 8  differs from the storage vessel  10  in its scraper  28 . 7 . The scraper  28 . 7  includes a single scraping arm  30 . 7 . This scraping arm  30 . 7  can have such a large area extending parallel to the bottom  16  that it simultaneously covers a plurality of (e.g., three or four) the orifices  24  in the bottom  16 . In contrast, the previously described scraper  28  of the storage vessel  10  ( FIGS. 1-6 ) can simultaneously cover or uncover all of the orifices  24 . Thus, in the case of scraper  28 . 7 , the orifices  24  closed in each case can remain closed for a longer period of time compared to scraper  28 , for similar speeds of rotation. As a result, compressed air can be conducted through the respective compressed air duct  40  into the chamber-like line region  20  for comparatively longer than is possible in the case of the scraper  28 .  
         [0038]     The invention has been described in detail with respect to preferred embodiments, and it will now be apparent from the foregoing to those skilled in the art, that changes and modifications may be made without departing from the invention in its broader aspects, and the invention, therefore, as defined in the appended claims, is intended to cover all such changes and modifications that fall within the true spirit of the invention.