Abstract:
The invention relates to a system for completely destroying documents having been shredded by document shredders, wherein the system comprises: 
     collecting means for shredded documents, 
     burning means being arranged together with collecting means, and 
     the burning means having a burning chamber for burning the shredded documents. 
     The burning chamber has an outlet with a filter unit and an air exhaust for remains of shredded documents that have been burnt.

Description:
TECHNICAL FIELD AND PRIOR ART 
     The invention relates to a system for destroying documents that have already been shredded by a document shredder. 
     In larger or office buildings there is a need for a plurality of office staff to have documents of critical relevance destroyed after having been read or after their use. Usually single document shredders are distributed in a building or provided in every room for documents to be shredded. The shredded documents are then collected and removed for example, by cleaning personnel. This gives the problem that the shredded documents could be put back together and their content read. Furthermore, such a system is not regarded as secure as it is not known what the cleaning personnel is doing with shredded documents. 
     OBJECTS OF THE INVENTION 
     It is an object of the present invention to provide a system for destroying documents that have been shredded by at least one document shredder wherein shredded documents are being destroyed securely and no remains are left. 
     It is a further object of the present invention to provide a system for destroying documents that is fit to be built in larger buildings. 
     According to the invention, the system includes central collecting means for shredded documents. Such central collecting means could be a pipe system or the like. Burning means are arranged together with the collecting means. This can be done in such a way that the collecting means lead to the burning means. The burning means can have one burning chamber or a number of burning chambers for burning shredded documents. The burning chamber again is connected with outlet means for the remains, or ash, of said shredded and burned documents. 
     Such a system provides a secure way for collecting shredded documents in that the documents are collected centrally, and then burned. As the documents are usually made of paper, they can easily be burned. Other forms of documents, such as CD&#39;s or floppy disks, can also be burned. From burned documents it is impossible to retrieve any information about their former content. Thus this method is a secure way for destroying documents even after shredding has already been provided. 
     According to one embodiment of the invention the burning means and the burning chamber can be adapted for burning shredded documents in a continuous process. This means that the shredded documents are being burned when they pass through the burning chamber. Such a continuous process, particularly for larger systems with a number of document shredders, allows the shredded documents to keep coming as they are being shredded. Thus the burning of shredded documents can not only be continuous, but also with no delay between shredding and burning. 
     According to an alternative embodiment of the invention, the burning means and the burning chamber are adapted for burning shredded documents in a non-continuous process, for example step-wise. This means that shredded documents can be collected to a certain amount or for a certain period of time and then burning is started. Collecting of shredded documents can be at any convenient place. For example, they are collected in the burning chamber itself. During such a collecting period burning should be stopped. Such a system is especially advantageous if the number of shredded documents is not so great or if they are not supplied continuously. 
     The burning chamber can be an enlongated channel. This provides a certain distance for shredded documents to pass through the burning chamber for better, more efficient, secure and complete burning. The burning chamber can, for example, be in the form of a pipe or the like. 
     According to one embodiment of the invention, the burning chamber can be equipped with burners. The burners can be gas burners. They can produce flames reaching into the burning chamber. The burning shredded documents can then be collected in or pass through the burning chamber. Gas burners are efficient and can be started easily and quickly. Of course other kinds of burners can be used within the scope of the invention. 
     It is also possible to heat the burning chamber where its insides are free of flames. Such a heating means can be installed in the burning chamber itself or surrounding the burning chamber. This method with an embodiment of a burning chamber being free of heating means or the like on the inside the system is very simple and secure in operation. Heating means, especially for arranging on the outside of the burning chamber and heating the burning chamber on the inside, can also incorporate electric heaters. Such electric heaters reduce the risk of explosions or fires by hazardous fuels. 
     The burning chamber can be connected with an exhaust system. Preferably the outlet means of the burning chamber can be connected with such an exhaust system. 
     Furthermore, the system or the outlet means can be connected to a separator filter. Such a filter or filter unit is preferably used for cleaning the exhaust air. According to one possible embodiment of the invention, the filter can be a fine filter unit. 
     The collecting means may include a vacuum stage and a pipe system. The pipe system is connected to a number of document shredders. The vacuum stage is adapted for transporting or guiding shredded documents from the document shredders to the collecting means or the burner. 
     Such a vacuum stage can be positioned after the burning means in the way shredded documents are taking after shredding. By this a vacuum stage can also be adapted for transporting remains of shredded documents leaving the burning chamber further along the system. 
    
    
     These and further features can be seen in the claims, description and drawings and the individual features. These can be both singly or in subcombinations implemented in an embodiment of the invention and in other fields. These can represent advantageous, independently protectable constructions for which protection is hereby claimed. The subdivision of the application into individual sections and subtitles does in no way limit the general validity of the statements made there under. 
     BRIEF DESCRIPTION OF THE DRAWINGS 
     Several embodiments of the invention are described in greater detail hereinafter relative to the attached drawings which show: 
     FIG.  1 : a system for shredding and burning documents, 
     FIG.  2 : an exemplary embodiment of a burning chamber with gas burners, and 
     FIG.  3 : another embodiment of the burning means with electric heating. 
     The view of the drawings is to be understood schematically. 
    
    
     DETAILED DESCRIPTION OF THE EMBODIMENTS 
     FIG. 1 shows a schematic view of a system  11  for shredding and burning documents. The system  11  comprises document shredders  13  being arranged as a plurality in a building  14  or the like. The document shredders  13  are connected with collecting means  15  via a pipe system  16 . The pipe system  16  is made up of a central pipe and several pipes leading from the central pipe to the document shredders  13  in a branch-like manner. 
     The collecting means comprise burning means  17  with a burning chamber  18  and a burner  19  or similar burning devices. The central pipe  16  leads into the burning chamber  18 . 
     With an outlet  20  the burning chamber  18  is connected to a fine filter unit  22  used for filtering the exhaust air of the burning chamber, specifically respective to ash or the like. Such a fine filter unit  22  is common in the art and needs not to be described in detail. The fine filter unit  22  could also be replaced by similar filtering means with the same functionality. 
     The fine filter unit  22  is connected via pipes to two vacuum units  24 . These vacuum units  24  function as a means for transporting shredded documents from the document shredders  13  through the pipe system  16  to the burning means  17  and then to the fine filter unit  22 . Furthermore, the vacuum units  24  are connected to an air exhaust  26 . Such an air exhaust is also known in the art and needs not to be described in detail. 
     In addition to the pipe system  16  being connected to the vacuum units  24  and being used for transporting shredded documents by drawing air in, a compressor system could be provided which could be switched upstream of the pipe system  16 . Using such a compression means pressurized air can be blown into the document shredders and the pipe system  16  to further enforce the shredded documents through the pipe system  16 . 
     In FIG. 2 an examplary embodiment of burning means  17  is illustrated. Burning chamber  18  is pipe like and runs substantially in a horizontal position. On the left, the burning chamber  18  is connected to the pipe  16 . On the right, burning chamber  18  is connected to the outlet means  20  in the form of another pipe. 
     Throughout the underside of the burning chamber  18  burners  19  are mounted. The burners  19  are gas burners  29  which reach into the burning chamber  18 . The gas burners  29  are connected to a gas pipe  30  and a gas valve  31  for turning on or off the gas. 
     The gas burners  29  produce a plurality of flames in the form of a row or a field covering a certain area. Shredded documents  28  falling into burning chamber  18  from pipe  16  are transported through the flames  32 , catch fire and are burned till they are ash  34 . The ash  34  is then removed moved out of the burning chamber  18  by way of the outlet means  20 . 
     It is to be understood from FIG. 2, that gas burners or other burning means producing flames can be arranged in many ways. 
     In FIG. 3 an alternative embodiment of burning means  17  is illustrated. Burning chamber  18  is constructed similarly to the one in FIG.  2 . Instead of gas burners  29 , an electric heater  36  in the form of a long pipe is provided. The electric heater surrounds the burning chamber  18  in screw-like manner. Alternatively, it is possible to provide an electric heater substantially underneath the burning chamber  18  or even inside the burning chamber  18 . The electric heater  36  is connected to electric connectors  37  which have a similar function to gas valve  31  in FIG.  2 . Via the connectors  37  the electric heater  36  can be energised. 
     With the electric heater  36  it is possible to heat the inside of burning chamber  18 . This can be in such a way that shredded documents  28  catch fire and are burnt to ash  34 . Alternatively, it is possible to transform shredded documents  28 , for example paper, directly into ash by heating only without any flames. 
     The ash  34  is removed through outlet means  20  to the filter unit  22 . The burning means  17  illustrated in FIGS. 2 and 3 are adapted for burning shredded documents in a continuous process. For burning shredded documents in a non-continuous process, it is possible to collect a certain amount of shredded documents in a position located prior to the burning chamber  18 . After having collected a certain amount of shredded documents they can be transported into the burning chamber  18   b  and be burned. 
     It is possible to collect a certain amount of shredded documents inside burning chamber  18  and then start the burner  19 . The choice between a continuous and a non-continuous process depends largely on the kind of documents or material of the documents to be shredded, the number of document shredders and several further aspects.