Patent Publication Number: US-2013233951-A1

Title: System for treating residues resulting from the combustion of a casket containing the body of a deceased person

Description:
TECHNICAL FIELD 
     The present invention relates to a system for treating residues resulting from the combustion of a casket containing the body of a deceased person. 
     BACKGROUND 
     When a deceased person is incinerated, his or her body is placed in a coffin—or casket—that is introduced into a furnace to be burned. At the end of the cremation, which lasts approximately 2hours, the residues are collected and brought to a receptacle called an ash pit. These residues comprise body remains, i.e., products of the combustion of the body that did not have time to be reduced to ash and therefore assume the form of pieces. These residues also comprise metal elements that come from any prostheses of the deceased (dental and/or joint prostheses), metal parts of the coffin (in particular the handles) and, if applicable, clothing or accessories worn by the deceased during the cremation. These metal elements also assume the form of pieces, which may be partially melted. 
     Currently, these residues are ground within the crematorium, then placed in an urn that is given to the family. 
     This has a certain number of drawbacks. 
     In fact, the ground residues comprise the ashes from the body of the deceased, but also metal shavings, in a non-negligible proportion of up to 40%. 
     Consequently, the volume of the urn does not make it possible to place all of the residues therein, as a result of which the urn cannot contain all of the ashes resulting from the body of the deceased, which is not desirable. 
     Thus, the part of the ground residues that cannot be placed in the urn is collected in a container located within the crematorium, that container being regularly emptied by specialized companies to treat those residues. This treatment consists of recovering the metals (precious, semiprecious or non-precious) for subsequent development thereof, and performing a complete combustion of the ground body remains. 
     However, the recovery of the metals in all of the ground residues is complex and expensive, since the metals are in the form of shavings and difficult to separate from the rest of the ground residues. 
     Furthermore, the fact that the urn also contains metal shavings is not satisfactory, as those metals cannot be recovered. 
     Systems for treating residues resulting from the combustion of a coffin containing the body of a deceased person are described in documents EP 0 829 682 and U.S. Pat. No. 3,770,215. 
     BRIEF SUMMARY 
     The present invention aims to resolve the aforementioned drawbacks. 
     To that end, the invention relates to a system for treating residues resulting from the combustion of a casket containing the body of a deceased person, the residues comprising body remains and metal elements, the system comprising:
         a device for sorting residues transported from the outlet of a cremation furnace to an urn, capable of separating the metallic elements and the body remains;   a device for grinding the portion of the residues that contain the body remains and is substantially devoid of metallic elements, said grinding device being positioned downstream of the sorting device;   at least a container for collecting the metallic elements, and an urn for collecting the ground body remains.       

     According to a general definition of the invention, the sorting device comprises:
         a valve movable between a first position, in which the valve covers a window of the sorting device opening toward a container for collecting the metallic elements, and a second position, in which said window is freed, the metallic elements then being able to drop through that window toward said container;   means for detecting the metals among the residues moved in the sorting device, the metal detection means being able to control the movement of the valve between the two positions thereof.       

     The terms “upstream” and “downstream” are used in reference to the direction of movement of the residues from their collection at the outlet of the furnace toward the urn. 
     Thus, the invention provides for separating the metallic elements from the rest of the residues before the grinding step, the method being implemented within the crematorium, and without human intervention. 
     This makes it possible to sort residues more easily, since the metallic elements are not in the form of shavings, but larger pieces. 
     Consequently, the residues that are ground are substantially free from metallic elements, and have a much smaller volume than in the prior art. As a result, all the ground residues can be placed in the urn, the latter then containing all of the ashes resulting from the body of the deceased person. Furthermore, the containers in which any excess ground residues would be placed will fill much more slowly. The operations aiming to empty these containers may therefore be done less often. 
     Furthermore, the invention makes it possible to recover the large majority of the metallic elements, therefore to recycle them almost in their entirety, which is also advantageous in economic and environmental terms. 
     One considerable advantage of the invention is that it makes it possible to perform a very effective and rapid sort, automatically and not manually, thereby avoiding psychologically difficult and potentially harmful operations for an operator. Furthermore, owing to the metal detection means coupled with the valve, the invention enables excellent recovery of the metals, for subsequent development thereof and for increased environmental respect. 
     It is specified that the main point, in the chronology of the method, is that the sorting and separating step is done before the grinding step, the collection step not necessarily been done after the sorting and grinding. It is thus possible to collect the metallic elements before the grinding of the residues that contain the body remains. 
     For example, the sorting step includes a first separation, comprising removing the ferrous metals from the rest of the residues, and a second separation, comprising separating the metals from the rest of the residues. The first separation may be done before the second: in that case, the second separation comprising separating the remaining metallic, therefore nonferrous, elements from the rest of the residues. Alternatively, the second separation may be done before the first: in that case, all of the metals (ferrous and nonferrous) are separated from the rest of the residues, then the magnetic metals are separated from the nonmagnetic metals. 
     Advantageously, the method provides for a separation of the different components of the residues using vibration, magnetism and gravity phenomena. By combining these three phenomena, the method is particularly effective. 
     According to one possible embodiment, the sorting device comprises a substantially horizontal conveyor equipped with vibration means capable of causing spreading of the residues in said conveyor. 
     Furthermore, the sorting device may comprise a substantially vertical column, in which at least part of the residues is made to drop. The conveyor may emerge, downstream, in the upper portion of the column. 
     The sorting device may comprise separating means including a magnet, for the recovery of the ferrous metals. These separating means are preferably positioned upstream of the metal detection means. However, it is possible to consider an inverse arrangement, and therefore later sorting between ferrous metals and nonferrous metals. 
     According to one possible embodiment, said separating means including a magnet are positioned above the conveyor. 
     It is also possible to provide one of the following configurations:
         the metal detection means are positioned on the column and the window is positioned on a side wall of the column; or   the metal detection means are positioned on the conveyor and the window is positioned on a lower wall of the conveyor or on a side wall of the column.       

     According to one possible embodiment, the system comprises a system for cooling the residues upstream of the sorting device. The system for example includes a container, such as an autoclave, associated with means for extracting the air in that container and with cooling means. One alternative solution comprises causing air to enter a container provided with an air outlet orifice that is very small (for example having a diameter of approximately 1/10 of a millimeter). Due to the overpressure of the area thus created, it is possible to lower the temperature in the container to approximately −8° C., which is very effective for cooling of the residues. 
     Advantageously, it is possible to provide that the sorting device is situated at a height with respect to the urn, such that the sorting and/or grinding step may be done at least partially by gravity, the system then comprising means for bringing the residues upstream of the sorting device arranged to move the residues upward as far as said sorting device. For example, the residues are conveyed from the autoclave, when the latter is provided, which is for example situated at more or less the same height as the urn. 
     The grinding device may comprise a first grinder, for example with cylinders, designed to perform a first grinding operation of said portion of the residues, and a second grinder, for example with a worm screw, positioned downstream of the first grinder and designed to perform a second, more fine grinding operation of said portion of the residues. 
     Such a structure of the grinding device makes it possible to reduce the noise level and the quantity of dust generated with respect to the grinding systems traditionally implemented in this field. Furthermore, such an advantageous grinding device can only operate because the metals have been separated from the body remains beforehand. 
    
    
     
       BRIEF DESCRIPTION OF THE FIGURES 
       We will now describe, as a non-limiting example, one possible embodiment of the invention, in reference to the appended figures: 
         FIG. 1  is a diagrammatic illustration of a system for treating residues according to the invention; 
         FIGS. 2 and 3  show positioning alternatives of the metal detection means and the valve in the sorting device; 
         FIGS. 4 and 5  are front and side views of a grinding device belonging to the system according to the invention. 
     
    
    
     DETAILED DESCRIPTION 
     The treatment system  1  according to the invention includes several devices arranged successively—or in parallel—from upstream to downstream, from the outlet of the cremation furnace toward an urn, said devices making it possible to sort and grind residues resulting from the combustion of a coffin containing the body of a deceased person. 
     When these residues are collected at the outlet of the furnace, they are incandescent and therefore cannot be treated directly. They therefore first undergo a cooling step. To that end, the residues are placed in an autoclave  2  having a cover  3  that can be closed by a push ram  4 . A vacuum pump  5  makes it possible to extract a large portion of the air present in the autoclave  2 , so as to stop the combustion. A refrigerated unit  6  coupled to a fan  7  then makes it possible to cool the residues quickly. As an example, the residues may go from a temperature of approximately 800° C. to a temperature of approximately 100° C. in about 15 min. Once the residues are cool, air is added to the autoclave  2  and the cover  3  is unlocked. 
     The residues thus cooled are then conveyed toward the downstream sorting and grinding devices, by intake means that may include a driving chain  8  with cups. The residues are thus moved from the top to the sorting device  9 , the latter being situated at a height to take advantage of gravity during treatment of the residues. 
     The sorting device  9  includes a substantially horizontal conveyor  10 , for example assuming the form of a round tube. The residues, conveyed by the cup driving chain  8 , are poured into an insertion member  11  of the hopper type, upstream of the conveyor  10 . 
     The conveyor  10  is equipped with a member  12  that vibrates the conveyor  10 , and thereby causes spreading of the residues at the bottom and along the conveyor  10 , while causing them to advance in the downstream direction. 
     A magnet  13 , preferably positioned above the conveyor  10  and downstream of the vibrating member  12  to act on the spread residues, makes it possible to perform a first sort of the residues, by removing the ferrous metals. These may thus be collected separately in a suitable container (not shown). 
     The rest of the residues (comprising nonferrous metals and body remains in pieces) continues its progression in the conveyor  10 , as far as the upper part of a substantially vertical column  14 , in which the conveyor  10  emerges. The remaining residues then drop into the column  14 . 
     In the embodiment of  FIG. 1 , the column  14  includes a window  15 , situated lower than the downstream end of the conveyor  10 , which may be sealed by a moving valve  16 . This window  15  emerges via a conduit  17  in a container  18  for collecting nonferrous metals. The column  14  is also equipped with metal detection means  19  of any known type, positioned between the downstream end of the conveyor  10  and the window  15 . The residues, during their drop in the column  14 , therefore pass in front of these metal detection means  19 . When the latter detects the passage of the metal, it commands the movement of the valve  16  from its sealing position of the window  15  toward a position in which said window  15  is freed, as illustrated in  FIG. 1 . 
     The rest of the residues, which therefore still contain the body remains in the form of pieces but are substantially free of metallic elements, continue to drop in the column  14  as far as a grinding device  20 . 
     The grinding device  20  first comprises a first grinder  21 , for example with cylinders, that performs the first grinding operation of said portion of the residues and prevents the system from becoming blocked by relatively large pieces that would become jammed in the column  14 . The grinding device  20  also comprises a second grinder  22 , for example with a worm screw, positioned downstream—therefore below—of the first grinder  21 , which performs a second, more fine grinding operation of said portion of the residues, typically to reduce them to a powder. 
     Positioned under the column  14  and the grinding device  20  is an urn  23 , placed on a holder  24  whereof the height can advantageously be adjusted. The ground body remains are thus collected substantially in their entirety in the urn  23 , which may be given to the family. 
     The height of the column  14  must be adapted to the response time of the device comprising the metal detection means  19  and the valve  16 , so as to obtain a good separation of the nonferrous metals and the body remains. As an example, the column  14  may have a height of approximately 2 to 3 m. With this size, it is possible to perform a very satisfactory sort, with less than 5% of body remains collected in the container  18  for collecting the nonferrous metals. 
     Positioning alternatives of the means for separating the components from the residues are illustrated in  FIGS. 2 and 3 . 
     First, the first separating means, i.e., the magnet  13 , are no longer placed above the conveyor  10 , but laterally with respect thereto, at the drop area of the residues from the hopper  11 . 
     Furthermore, the metal detection means  19  are positioned on the conveyor  10 , preferably downstream of the magnet  13 . 
     In the embodiment of  FIG. 2 , the window  15  is positioned on a side wall of the column  14 , preferably just downstream of the conveyor  10 , when the latter emerges in the column  14 . In the embodiment of  FIG. 3 , the window  15  is positioned on a lower wall of the conveyor  10 , downstream of the metal detection means  19 . 
     Reference will lastly be made to  FIGS. 4 and 5 , which more precisely show one possible embodiment of the grinding device  20 . 
     The grinding device  20  comprises a first grinder  21  having two cylinders  25  (or rollers) positioned at the same height and rotating around parallel horizontal axes  26 ,  27  in opposite directions. The bone residues are pre-ground between the two cylinders  25 . 
     A funnel  28  is provided under the first grinder  21  to lead the body remains to the inlet of the second grinder  22 , which is a worm screw grinder positioned horizontally. The second grinder  22  is driven by a motor  29 , generally an electric motor. The second grinder  22  includes an outlet grate  30  for the body remains reduced to powder and blades or knives  31  allowing the ground body remains to pass through the holes of the grate  30 . Lastly, a funnel  32  is provided guiding the passage of the body remains toward the urn  23 . 
     Thus, the invention provides a decisive improvement to the prior technique, by providing a method and a system that are both more satisfactory for the families of the deceased, in that the urn given to them contains all of the ashes resulting from the body, and from an environmental and economic standpoint, in that the metal recovery rate is considerably increased. 
     The invention is of course not limited to the embodiment described above as an example, but on the contrary encompasses all technical equivalents and alternatives of the described means as well as combinations thereof.