Abstract:
The invention relates to a conveying system for powdery products, particularly cement, which are placed in packages, preferably sacks. The aim of the invention is to improve this conveying system whereby simplifying the handling when obtaining and providing the products in packages. To this end, a holding unit is provided to which the unopened packages containing the product can be supplied. A comminution machine is connected down from said holding unit and serves to comminute the packages. A conveying device and/or a conveying unit is/are located down from said comminution machine and serve(s) to convey the product together with the package parts leaving the comminution machine.

Description:
BACKGROUND OF THE INVENTION  
       [0001]     The invention relates to a conveying system for powdery products, especially cement, that can be transported in sacks.  
         [0002]     It is known that powdery products, especially cement, can be transported in silos or other containers as well as in sacks as so-called sack goods. Transport in silos or with silo vehicles is quite problematic in regions that do not have adequate infrastructure for large silo vehicles. Thus, for example, it is not possible simply to deliver cement to major construction sites in remote regions using conventional large silo vehicles when there is a lack of suitable roads. In addition, experience demonstrates that construction of suitable transport systems or transport arteries is quite complex and frequently undesired, for instance from an environmental perspective.  
         [0003]     Furthermore, there are difficulties when erecting large cement silos is not permitted at the construction site, for instance in protected areas. On the other hand, delivering cement as sack goods requires additional complexity in terms of opening and emptying the sacks, and the problems caused by cement swirling in the air and associated contamination of the environment as well as the loss of not inconsiderable residual quantities of cement in the sacks have proved disadvantageous. Moreover, once the sacks have been emptied, disposing of them as waste products constitutes another complicating factor.  
       BRIEF SUMMARY OF THE INVENTION  
       [0004]     The object of the invention is therefore to avoid the aforesaid disadvantages and to simplify handling during procurement and provision of the products in packagings, in particular sacks or as sack goods. The conveying system should have a simple design and functionally assured construction and should facilitate economic operation. Moreover, conveyance and use that handles the powdery product gently, especially cement, should be assured. Furthermore, additional complexity in terms of the disposal of the packagings or sacks should be avoided.  
         [0005]     The inventive conveying system is distinguished by a simple functionally appropriate design and simplifies handling during procurement of the powdery product, in particular cement, by means of sack goods and also simplifies easy and cost-effective disposal of the sacks or packagings in general. The inventive conveying system contains a comminution machine by means of which the packagings are comminuted such that their comminuted components are integrated into the subsequent processing and in particular are worked into the concrete.  
         [0006]     The sacks that have not been opened in advance and that are supplied to the conveying system together with the product disposed in the sacks are introduced into the conveying system, whereby the sacks are comminuted and thus also opened by means of the comminution machine. The sacks with their contents are processed by means of the comminution machine so that subsequently the comminuted components of the sacks can be further processed and in particular mixed into the cement. The comminuted packagings are integrated into the subsequent process and then in particular worked into the concrete.  
         [0007]     Loss of residual quantities of product with the packaging is avoided and there is no need to dispose of the packaging separately. The system thus contributes to relieving the burden on the environment in terms of disposing of the residual material and protects raw material resources. The packagings do not have to be opened individually, which results in not inconsiderable savings in work and time. The conveying system is employed inventively for any powdery products that can be transported for use, in particular as sack goods, whereby at this juncture, apart from cement, mention should be made of products from the chemical industry, for instance granulates and bulk goods of all types that can especially be conveyed pneumatically. Powdery products in this context are also products that are coarser than e.g. cement, such as granulates.  
         [0008]     If the conveying system is used in the production of concrete, quite cost-effective cement supply is assured in particular at temporary major construction sites and it is not necessary to use special silo vehicles. For instance, approx. 360 t cement can be conveyed in a 24-hour operation, which corresponds to a solid concrete yield of approx. 1200 t per day. Once the major construction site is completed, the conveying system, which is called a cement supply station or discharge and filling station, is able to ensure the supply of cement without any problems for years thereafter. Furthermore, the inventive conveying system can be employed in small preparation systems where the erection of large cement silos is not permitted, for instance in protected areas. The conveying system can also assure the cement supply when infrastructure is inadequate, especially when employed in Third World countries in which it is not practically possible to obtain cement in silos.  
         [0009]     In addition, it is particularly significant that the inventive conveying system can be simply transported in a simple manner due to the frame that receives the components to be described in the following, especially the exterior dimensions of the conveying system and/or of the frame do not surpass the exterior dimensions of a container and thus permit transport on any truck or low loader without a special permit. Advantageously, the exterior dimensions of the conveying system and/or its frame correspond to those of a standardized container, specifically especially with a length of 6 m, width of 2.44 m, and height of 3 m. The conveying system can be stacked like a container and thus facilitates space-saving transport by sea to assure delivery worldwide. Construction and transport are rendered substantially easier due to the inventive conveying system being designed like a container.  
     
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0010]     The invention is described in greater detail in the following using the exemplary embodiments illustrated in the drawings, without this resulting in restrictions, in which:  
         [0011]      FIG. 1  illustrates the conveying system in principle;  
         [0012]      FIGS. 2, 3  are side elevations of a first exemplary embodiment;  
         [0013]      FIGS. 4, 5  are side elevations of another exemplary embodiment with a pallet elevator; and  
         [0014]      FIG. 6  is an elevation of the conveying system in accordance with  FIG. 4 , but without the pallet elevator. 
     
    
     DETAILED DESCRIPTION OF THE INVENTION  
       [0015]      FIG. 1  illustrates the principle of the inventive conveying system with a receiving unit  2  that preferably includes a funnel  4  or is embodied as one. The products, delivered and provided in packagings, in particular sacks, are delivered into the receiving unit  2 , specifically with the packagings, which preferably have not been opened in advance. From the receiving unit  2 , the packagings and their contents travel to a comminution machine  8  that is usefully arranged directly below the receiving unit  2 . The comminution machine  8  includes cutting elements  10  such as knives or the like that are arranged and designed such that the packagings are comminuted, whereby the products previously contained therein, such as in particular cement, are released.  
         [0016]     The comminution machine  8  and/or its cutting elements  10  are embodied and arranged such that the packagings can be separated and/or torn into a plurality of small pieces, whereby their exterior dimensions are preferably at least primarily on the order of magnitude of a maximum of a few centimeters and/or their surface areas are at least primarily on the order of magnitude of a few square centimeters. The comminution machine  8  and/or its cutting elements  10  are usefully matched to the requirements for the product, in particular cement, in terms of further processing, in particular for concrete.  
         [0017]     Thus, in practical tests it could be determined that the packaging parts worked into the concrete are not associated with any negative effects in terms of quality when the edge lengths are up to 5 cm, preferably up to 3 cm, and in particular up to 2 cm. The comminution machine  8  preferably contains at least two rotating cutting units  12  that are driven by means of a preferably electric drive motor (not illustrated).  
         [0018]     Downstream of the comminution machine  8  is a transfer device  14  that here is embodied preferably as a transfer funnel that is arranged below the comminution machine  8  and that is joined in particular securely thereto. The product and the packaging parts blended therewith are fed by means of the transfer device  14  to a conveyor unit  16  that is embodied in particular as a metering spiral conveyor  16  or that includes one. Downstream of the conveyor device  16  is at least one conveyor unit  18 ,  19  that is preferably embodied as a pressure vessel conveyor.  
         [0019]     System output can be prespecified advantageously by specifying the number and/or size of the conveyor units or pressure vessel conveyors  18 ,  19 . Thus for instance in a cement system with a single pressure vessel conveyor of 1000 liters, a system output of 10 t/h can be prespecified and when a second pressure vessel conveyor is employed a system output of 20 t/h can be specified. In addition, the pressure vessel conveyor(s)  18 ,  19  is or are preferably embodied as balances. As can be seen, upstream of the pressure vessel conveyors  18 ,  19  is an air container  20  to which the air drawn through an air filter  26  is fed as compressed air via a water separator  22  and compressor  24  through appropriate piping.  
         [0020]     The air container  20  communicates with the pressure vessel containers  18 ,  19  via appropriate piping  28  that contains valves as is known, as illustrated. If more than one conveyor unit or pressure vessel conveyor are present, advantageously provided between these and the conveyor device  16 , in the connecting line(s)  32 , is a distribution unit  34  that is embodied in accordance with the drawing in particular as a two-way or multi-way distribution in order to selectively feed the product with the packaging parts to the one or the other conveyor unit  18 ,  19 .  
         [0021]     In addition, in one alternative special embodiment of the invention a cleaning unit  36 , indicated with a dashed line, can be preferably downstream of the comminution machine  8 . This cleaning unit  36  contains suitable means, such as rakes or coarse sieves or filters, for separating out in particular relatively large or coarse pieces of packaging from the actual product to be conveyed. Advantageously the cleaning unit  36  is embodied such that it is possible to perform self-actuated and/or automatic cleaning of the aforesaid means in order to assure their proper cleaning function even in continuous operations.  
         [0022]     The at least one conveyor unit  18 ,  19  includes an output line  38 ,  39  for connecting and for preferably pneumatic further conveyance, in particular to a silo  40  or other storage unit. As indicated with the dashed line  42 , the silo  40  does not belong to the inventive conveying system. In accordance with the above description, the inventive conveying system is embodied as a discharge and filling station for powdery or granular products that are supplied in packagings and that can be conveyed pneumatically.  
         [0023]     It should be established that, instead of the embodiment described in the forgoing, in the framework of the invention the conveying system and/or cement sack discharge and filling station can also be employed for other powdery and pneumatically conveyable products that can be transported and provided as sack goods or in packagings. What is essential is that the packagings are comminuted and integrated into the further process and that they are subsequently worked into the final product.  
         [0024]      FIG. 2  is a side elevation of the conveying system and  FIG. 3  is a view in the direction of the arrow III in accordance with  FIG. 2 . The conveying system includes a frame  44  that is designed such that the components described above are combined in one compact unit or are integrated into one compact unit. The conveying system and in particular the aforesaid frame  44  are designed such that they conform to the exterior dimensions of a standardized container. The exterior dimensions of the conveying system and the frame are preferably as follows: length 46=6 m, width 48=2.44 m, height 50=3 m.  
         [0025]     Thus the conveying system is afforded a high degree of flexibility and can be transported with no problem with any truck or low loader, specifically without a special permit, and is stackable like a container. Furthermore, due to the container-like design, space-saving transport by sea is possible for assuring world-wide delivery with no problem.  
         [0026]     The frame  44  is advantageously provided with a roof  52  above. In addition, a pivotable cover  54  is allocated to the receiving unit  2  or the funnel  4 , specifically thereabove. The cover  54  is secured against the risk of accidents by means of a securing element  56  that is advantageously embodied as a coded security limit switch and/or in particular is arranged such that the system cannot be operated unless the cover  54  is closed. The security element  56  is in particular arranged flush with the upper edge of the receiving unit  2  or the funnel  4 . Arranged below the funnel  4 , which is also characterized as a sack funnel, is the comminution machine  8  and thereunder is arranged the transfer funnel  14 .  
         [0027]     With respect to the creation of dust that is to be expected, in order to prevent components of the product from escaping into the environment an aeration device  58  is advantageously provided in the area of the comminution machine  8 . It should be stated here that, apart from the upper opening of the receiving unit  2  and the output line, the various components are sealed to the outside and/or are sealed securely to one another in order to prevent the undesired escape of the powdery product to the outside. Thus the inventive system is a system that is closed to the outside, relative to the conveying flow of the product, with which product provided in closed packagings is conveyed from the receiving unit  2  through the comminution machine  8  to the output line or lines ( 38 ,  39 ) and into a silo  40  or the like that is also sealingly attached thereto.  
         [0028]     Furthermore a control cabinet  60  is arranged in the frame  44 , usefully in a control cabinet. The complete process from feeding the packaged product into the receiving unit  2  to blowing it out through the output line  38  or blowing it into the downstream silo is controlled and/or regulated and assured by means of the control unit. The above explanations for  FIG. 1  apply with respect to the other components.  
         [0029]      FIGS. 4 and 5  are side elevations and  FIG. 6  is a top view of another exemplary embodiment of the conveying system that is combined with an elevator  62 , in particular a pallet elevator. The pallet elevator  62  is arranged on the longitudinal side of the conveying system and usefully makes it possible to feed the sacks  64  that are in particular filled with cement. In accordance with  FIG. 4 , arranged beneath the funnel  4  is a loading unit  80  to which the individual sacks  64  travel. By means of the loading unit  80  the unopened packagings or sacks are fed to the comminution machine  8  to be torn apart or comminuted.  
         [0030]     As can be seen in particular from  FIG. 5 , a pallet  66 , upon which a number of cement sacks  64  is stacked, is first brought into the lower position  68  of the pallet bearer  70  movably arranged in the pallet elevator  62 , for instance by means of a fork lift, and is then conveyed to an upper position  72 . The pallet elevator  62  includes guide rails  74 ,  76  such that in the upper position  72  the pallet bearer  70  is pivoted or tipped and the cement sacks  64  travel from above into the receiving unit  2  and the funnel  4 . The lid  54  pivotably arranged on the upper edge of the receiving unit  2  is open. Subsequently the lid  54  is closed, preferably by means of an actuating unit  78 , whereby by means of the previously explained securing element  56  a signal is provided in a suitable manner to the control unit  60  via which the process described above is controlled and/or regulated.  
         [0031]     The present invention may be embodied in other specific forms without departing from its spirit or essential characteristics. The described embodiments are to be considered in all respects only as illustrative and not as restrictive. The scope of the invention is, therefore, indicated by the appended claims and their combination in whole or in part rather than by the foregoing description. All changes that come within the meaning and range of equivalency of the claims are to be embraced within their scope.