Abstract:
An apparatus and a method for treating organic waste, like the waste that is eliminated in kitchens, foresee containing the waste ( 15 ) to be treated, grinding the waste, compacting the ground waste and exerting a squeezing action to remove residual liquids. A screw device ( 17 ) is foreseen which rotates inside a casing ( 18 ) around a longitudinal axis to convey and compact the ground waste against a closure ( 19 ) which moves during compacting. A solution for cleaning the apparatus is also foreseen to remove remaining any waste, when the apparatus needs to stay empty for longer periods of inactivity.

Description:
FIELD OF THE INVENTION 
       [0001]    The present invention concerns improvements to an apparatus for treating organic waste of various types, like vegetables, fruit and other food waste. By using the apparatus of the invention fine grinding and compacting of the waste occurs before the waste is delivered to a public collection centre. Consequently, the volume of the waste is reduced, which limits the environmental impact, limits the remaining humidity of the ground waste to avoid bacteria, and avoids fermentation and bad odours. Furthermore, the apparatus makes it possible to accomplish differentiated collection of the waste and to produce compost. 
       BACKGROUND OF THE INVENTION 
       [0002]    An apparatus of this type needs to be suitable for a practical use, which comprises the steps of introducing the waste to be ground, grinding the waste, compacting and squeezing the ground waste to extract the residual liquids, therefore to reduce the volume and achieve the dehumidification of the waste. Finally, the treated waste needs to be discharged without manually intervening on it. 
         [0003]    The apparatus of DE 317 788 mixes and possibly breaks portions of substances with agitator 17. This apparatus is not suitable for treating ground waste that is cut by using cutting blades. 
         [0004]    The apparatus needs to be easily emptied of the waste, when the apparatus needs to be stopped for long periods of inactivity. 
         [0005]    The movement mechanisms of the apparatus need to be reliable and simple to guarantee a long life of the apparatus and a minimum amount of maintenance operations. 
         [0006]    Furthermore, the apparatus needs to allow facilitated cleaning to remove remaining waste, when the apparatus is emptied for long periods of inactivity. This problem is particularly felt when compacting organic kitchen waste present in homes, refectories, restaurants, etc., where frequent disinfection of the machine is necessary to avoid bad odour and bacterial presence. 
       SUMMARY OF THE INVENTION 
       [0007]    It is therefore an object of the invention to provide an apparatus for treating waste, in particular organic waste, which overcomes the above mentioned problems. 
         [0008]    It is a further object of the invention to provide an apparatus for treating waste, which is capable of improving the compacting step and the dehumidification of the waste, thereby achieving an optimal separation of the liquid parts from the solid parts. 
         [0009]    It is a further object of the invention to provide an apparatus for treating waste in which compacting and extraction of remaining liquids occurs and that can be easily emptied of the waste when the apparatus needs to be stopped for long periods. 
         [0010]    It is also an object of the invention to provide an apparatus for treating waste where ordinary maintenance can be easily carried out and allowing facilitated extraction and cleaning of the parts where passage of the waste occurs. 
         [0011]    These and other objects are achieved by the apparatus and the method for treating the waste according to claims  1 ,  10 ,  15  and  19 . 
         [0012]    Further characteristics are defined by the dependent claims. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0013]    Further characteristics and advantages of the apparatus and the methods according to the invention will result more clearer from the description which follows of 
           [0014]      FIG. 1  is a general partial section view of the apparatus according to the invention; 
           [0015]      FIG. 2  is an enlarged view of the sectioned part of the apparatus shown in  FIG. 1 , although showing the lid of the machine in an open position and with the waste to be treated that has been introduced in the loading section; 
           [0016]      FIG. 3  is a partial prospective view of a portion of the apparatus, as seen from direction  3  of  FIG. 1 ; 
           [0017]      FIG. 4  is a partial section of portion  4  of  FIG. 2 , illustrating a second embodiment of the invention; 
           [0018]      FIG. 5  is a partial view from directions  5 - 5  of  FIG. 2 ; 
           [0019]      FIGS. 6   a  to  6   f  are partial section views of area  6  of  FIG. 2  illustrating operation cycles of the apparatus according to the invention. 
           [0020]      FIG. 7  is a view similar to the view of  FIG. 2  illustrating a solution for cleaning the apparatus according to the principles of the invention. 
       
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENTS 
       [0021]    With reference to  FIGS. 1 and 2 , an apparatus  10  for treating waste in particular organic waste, comprises from above to below a loading section  11 , a grinding section  12 , a waste compacting and dehumidification section  13 , and a section  14  for collecting the treated waste. 
         [0022]    A possible succession of working steps of the apparatus starts when the loading section  11  is opened for introducing the waste  15  to be treated (see  FIG. 2 ) 
         [0023]    The loaded waste  15  falls into the grinding section  12 . This section is provided with grinding means  16 , for example a series of blades located on the periphery of two drums which rotate opposite to each other, like those described in Italian Application PI 2007A000050, to accomplish e fine grinding of the waste. Below the grinding means  16 , the ground waste falls through aperture  15 ′ of casing  18  into the vanes  17 ′ of a helical screw device  17 . 
         [0024]    Helical screw device  17  is provided with a longitudinal axis  17 ′ within casing  18  and is capable of rotating around this longitudinal axis. The rotation of helical screw device  17  conveys ground material against and in front of a wall  19   a  of a closure  19  (see  FIG. 6   a - 6   d ). 
         [0025]    As the material M progressively accumulates against the closure  19 , relative movement of the closure  19  occurs with respect to the helical screw device  17  along a path that is substantially parallel to the axis of the helical screw device  17 . 
         [0026]    In the embodiment of  FIGS. 1 and 2 , the closure  19  moves backwards in direction T due to the force applied on closure  19  by the ground material positioned in front of it and that is being pushed by the screw portion of helical screw device  17 . 
         [0027]    In this way, the material M in front of closure  19  undergoes a compression action, which compacts and squeezes it to cause residual liquid to be extracted. During compacting no discharge of the compacted waste occurs. 
         [0028]    For these reasons, a bored casing  20  is provided inside the final portion of casing  18  where the material M accumulates to allow liquid to be extracted as the squeezing occurs. 
         [0029]    Casing  18  is provided with an exit  50  connected to a conveying duct  21 ′ through which liquid  21  is discharged from the apparatus. 
         [0030]    Closure  19  is provided with a rear part  19 ′ (see  FIGS. 2 and 5 ) where two shaped grooves  22 ′ and  22 ″ are foreseen. Shaped groove  22 ′ on the top side of rear part  19 ′ is shown in  FIG. 5 . Shaped groove  22 ″ is present on the lower side and is similar to shaped groove  22 ′. In each shaped groove  22 ′ and  22 ″, a respective pin  25 ′ and  25 ″ is engaged as shown in  FIGS. 2 and 5 . Groove  22 ′ comprises a first straight part  22   a , an inclined part  22   b , a transverse part  22   c  and a second straight part  22   d . Pins  25 ′ and  25 ″ are the ends of arms  25  which are hinged to cover  23  by means of pin (see  FIG. 2 ). 
         [0031]    Therefore pins  25 ′ and  25 ″ have the possibility of moving in the plane that is perpendicular to the plane containing  FIG. 2 , i.e. like the plane containing  FIG. 5 . 
         [0032]    Closure  19  is guided by the engagement of its external surface against the internal surface  23 ′ of cover  23  as the latter moves in directions T and T′, as shown in  FIG. 2 . Springs  24  that are preloaded with a compression force and placed between cover  23  and closure  19  push closure  19  in direction T′, which is opposite to direction T. In this way, there has been achieved one of the possible embodiments provided by the invention of the means for guiding that allow a translation movement of closure  19  along the axis  17 ″ of the screw device  17 , and of the contrast means located beyond the closure  19  and opposite to the screw device  17 . When the screw device  17  pushes on material M that is accumulated in the volume of the casing in front of closure  19 , springs  24  exert an opposite force on member  19 . 
         [0033]    The two opposite forces obtained in this manner accomplish squeezing extraction of liquid  21  and compacting of material M. 
         [0034]    During this sequence of forces, see  FIGS. 6   a  and  6   b , during a first backward movement step of closure  19  in direction T, pins  25 ′ and  25 ″ move in the straight portion  22   a  of the shaped guide  22 ′ of part  19 ′. During a second step of the backward movement of closure  19 , pins  25 ′ and  25 ″ move in the inclined part  22   b , and during the final step of the backward movement of closure  19 , pins  25 ′ and  25 ″ move in the transverse parts  22   c.    
         [0035]    When pin  25 ′ or pin  25 ″ are in the transverse parts  22   c , a situation signalled by a sensor not shown in the figures, the rotation of the screw device  17  is stopped. At the same time pins  25 ′ and  25 ″ become located in the position that causes an engagement connection of the closure  19  to cover  23 , see the position of pin  25 ′ shown in  FIG. 5 . 
         [0036]    As a result, closure  19  is no longer free to move with respect to cover  23  due to engagement of pins  25 ′ and  25 ″ in the seat portion of groove  22   c , which renders closure  19  and cover  23  connected and integral, as shown in  FIG. 5  for pin  25 ′. 
         [0037]    At this point cover  23  can be opened and closure  19  moves with it to free the exit opening  18 ′ of casing  18  to discharge the compacted material M, as shown in  FIG. 6   d.    
         [0038]    Then, screw device  17  translates in direction T to push the compacted material M through the exit opening  18 ″ out of casing  18 , as shown in  FIG. 6   e.    
         [0039]    During the translation, screw device  17  is guided by the internal surface of casing  18 . At the end of the travel of the screw device  17  in direction T, end  27  of the screw device reaches the position that extends beyond the edge of the end of casing  18 , as shown in  FIG. 6   f.    
         [0040]    Once material M has been unloaded, cover  23  is closed to start a further step of squeezing and compacting. During the travel of cover  23  to be closed, closure  19  engages the end  27  of screw device  17 . During this engagement and the travel of cover  23  to become closed, pins  25 ′ and  25 ″ become free from the seats of the transverse parts like  22   c  of shaped grooves  22 ′ and  22 ″, and consequently closure  19  becomes disconnected from cover  23 . 
         [0041]    At this point, cover  19  follows the backward movement of screw device  17  in direction T′ because closure  19  is being pushed by springs  24 , whilst the end  27  of screw device  17  acts like a moving engagement surface to withhold uncontrolled backward movement of closure  19 . 
         [0042]    During the backward movement in direction T′, pins  25 ′ and  25 ″ relatively move in stretches like  22   d  and  22   a.    
         [0043]    For the steps described in the foregoing where the cover  23  is opened and closed to remove, or replace closure  19  a drive mechanism  55  (dash line representation in  FIG. 6   f ) is provided which rotates cover  23  around a hinge mechanism  56  of casing  18 , as shown in  FIGS. 6   d - 6   f.    
         [0044]    The complete closure of lid  23  and the backward movement of the screw device  17  in direction T′ bring closure  19  in the most forward position (see  FIG. 2 ) to repeat the squeezing and compacting cycle by using rotation of screw device  17 . 
         [0045]    With reference to  FIGS. 2 and 3 , the screw device  17  is rotated by actuating the motor reduction drive  30  with a rotation direction that causes pushing action of screw device  17  on material M. 
         [0046]    Drum  32  is assembled in a fixed manner on the end of exit shaft  31  of motor gear drive  30 , visible in  FIG. 2  however not visible in  FIG. 3  for reasons of clarity. 
         [0047]    The free wheel  33  is assembled between drum  32  and end  34  of screw device  17 , as shown in  FIG. 2 . The rotation direction of the motor reduction drive  30  causes the pushing action on behalf of the screw device  17 , and consequently also the direction that the free wheel  33  uses for transmitting the rotation torque of screw device  17 . 
         [0048]    During the opposite rotation of the motor reduction drive  30  (opposite rotation in the following), the freewheel  33  remains idle, which makes drum  32  idle with respect to end  34  of the screw device  17 . Therefore no rotation torque is transmitted, thereby excluding rotation of screw device  17  during opposite rotation of motor reduction drive  30 . 
         [0049]    The free wheel  33 ′ is assembled between drum  35  and the exit shaft  31  of motor reduction drive  30 . The external surface of drum  35  is provided with groove  36 , which has a cam profile. The motor reduction drive  30  is provided with bars  38  (see  FIGS. 2 and 3 ) that can run in supports  37  of the frame of the apparatus. 
         [0050]    The roller  39  of an arm fixed to the frame of the apparatus can engage the internal surfaces of groove  36  (see  FIG. 3 ). Therefore when motor reduction drive  30  rotates with the opposite rotation, the free wheel  33 ′ transmits rotation torque to drum  35  and groove  36  rotates when the roller  38  is engaged with it. This causes translation in direction T or T′ of the motor reduction drive  30  and the screw drive  17  that is integral to it. Depending on the stretch of groove  36  which is travelled by roller  39  the translations occur in direction T and T′ of screw drive  17 , as is required in the cycles described in the foregoing with reference to  FIGS. 6   e  and  6   f.    
         [0051]    Based on the principles described above and with reference to  FIGS. 6   e  and  6   f  the result is that the apparatus can easily be emptied of the waste that is present inside, and particularly when the apparatus needs to be stopped for long periods of time. 
         [0052]    The possibility of being able to remove closure  19  favours access to the area of casing  18  where the compacting and the squeezing of residual liquid occurs. In this way the operations to remove remaining waste and cleaning becomes facilitated. 
         [0053]    As shown in  FIG. 2 , casing  18  results slightly inclined with respect to the horizontal plane. This creates a slope that allows a part of the liquid  21  present in casing  18  to flow towards exit  43  (see  FIG. 1 ). This liquid can be present in the material conveyed by the screw device or other liquid poured into the loading section  11 . 
         [0054]      FIG. 4  shows a second embodiment of the cover  23 . In this case, closure  19  is moved in directions T and T′ by an actuator  41  that is integral with cover  23 . Actuator  41  pushes or pulls shaft  40 , which is assembled integral with closure  19 . Actuator  41  is connected to the drive and control unit  42 . Sensor  45  is also present for measuring the displacement of closure  19 , or the force exerted on closure  19  during compacting. 
         [0055]    By means of particular movements of closure  19  or force reactions of closure  19  produced by actuator  41 , and which are programmed and controlled by unit  42 , it is possible to optimize compacting of the material M and squeezing of liquid  21 . 
         [0056]    In the above mentioned description, the movement of closure  19  with respect to screw device  17  has been created in opposition to the force of preloaded spring  24 , or by the force exerted using actuator  41 . Other equivalent means are available in the art for generating the force opposing the movement of closure  19 , for example viscous dampers, or elastic dampers or a combination of these. 
         [0057]      FIG. 7  illustrates a solution for cleaning the apparatus once the waste has been emptied by following the principles described with reference to  FIGS. 6   d - 6   f.    
         [0058]    A sprinkler device  70  and detergent dispenser devices  71  can be assembled on the lid  90  of loading section  11  as shown in  FIG. 7 . Valve  82  intercepts any discharge of liquid from collector  83 . Collector  83  is foreseen for receiving liquid leaving casing  18  though apertures  83 ′ and  83 ″ during normal operations of the machine. Sprinkler device  70  is connected by piping  72  to liquid reservoir  73 . Liquid reservoir  73  can receive water or other cleaning liquid from supply piping  75  and can be provided with a heating resistance  74  for heating the liquid that needs to reach sprinkler device  70 . Valve  76  intercepts the flow of liquid through piping  75 . By opening valve  76  heated liquid from reservoir  73  passes to sprinkler device  70 , which rotates and dispenses heated liquid in loading section  11 . During dispensing of the liquid, valve  82  can be closed to avoid discharge from collector  83 . The sprinkler device can continue to dispense the liquid to reach the condition that screw device  17  and the grinding means  16  are submerged, like is shown in  FIG. 7 . A level sensor like  77  can determine when the liquid has reached the submerging level shown in  FIG. 7 , and causes control  80  to close valve  76 . As an alternative to the use of sensor  77 , or combined with the use of sensor  77 , a flow sensor  77 ′ can measure the flow of liquid reaching reservoir  73 , which indirectly is a measure of the flow of liquid being sprayed by sprinkler  70 . Controls  80  receiving the measurement signal from sensor  77 ′ can determine when a predetermined quantity of liquid has been discharged in the apparatus after discharge vale  82  has been closed. Based on this determination valve  76  can be closed to continue the cleaning sequence of the apparatus. 
         [0059]    Detergent D can also be dispensed by detergent dispenser devices  71  on the walls of loading section  11 , as shown in  FIG. 7 . Detergent D is fed from tank  81  through piping  79  by pump  84 . Detergent D can be a cleaning and sanitizing solution for guaranteeing optimal conditions of sanitary safety. 
         [0060]    When the submerging level sensed by sensor  77  and controls  80  has been reached, or a predetermined level of liquid has been fed through sprinkler  70  sensed by flow sensor  77 ′ in combination with controls  80 , and after a certain period of waiting time, grinding means  16  and screw device  17  can be rotated to favour cleaning and detachment of waste from the surfaces of the apparatus. Once this step of rotation has been terminated, valve  82  can be opened and pump  85  activated to discharge the liquid. After this discharge has occurred, screw device  17  can be rotated to convey any detached waste against closure  19 . Then screw device  17  can be caused to travel in direction T to push closure  19  in direction T and cause it to become connected to cover  23  by means of pins  25 ′ and  25 ″, as described in the foregoing. This situation can allow cover  23  to be opened so that screw  17  can move further in direction T to discharge the detached waste. 
         [0061]    The foregoing description of a specific embodiment will so fully reveal the invention according to the conceptual point of view, so that others, by applying current knowledge, will be able to modify and/or adapt for various applications such an embodiment without further research and without parting from the invention, and it is therefore to be understood that such adaptations and modifications will have to be considered as equivalent to the specific embodiment. The means and the materials to realise the different functions described herein could have a different nature without, for this reason, departing from the field of the invention. It is to be understood that the phraseology or terminology employed herein is for the purpose of description and not of limitation.