ORGANIC WASTE TREATMENT

1 . An apparatus ( 2 ) for pretreatment of organic waste from the Organic Fraction of Municipal Solid Waste and/or from food industries, upstream of an anaerobic digester, the apparatus comprising:

a squeezing-diluting-unpacking module ( 4 ) configured to receive an input waste stream ( 3 ) of packaged waste and a dilution fluid ( 10 ), to lacerate packaging of the packaged waste, and to output a coarser non-digestible stream ( 23 ) and a comparatively dirty and comparatively liquid slurry ( 26 ),

at least one settling module ( 30 , 30 a ) connected to receive the comparatively dirty and comparatively liquid slurry ( 26 ) and configured to allow inerts in the comparatively dirty and comparatively liquid slurry ( 26 ) to sediment and to output a finer inerts stream ( 40 ) and a comparatively refined slurry ( 42 ),

a thickening/dewatering module ( 60 ) connected to receive the comparatively refined slurry ( 42 ) and configured to separate and output a liquid stream ( 69 ) and a comparatively dewatered slurry ( 72 ) wherein the comparatively dewatered slurry ( 72 ) is output to the anaerobic digester and the liquid stream ( 69 ) is connected to supply liquid making up at least part of the dilution fluid ( 10 ) received at squeezing-diluting-unpacking module ( 4 ).

2 . The apparatus ( 2 ) of claim 1 , further comprising:

a dry matter content sensor ( 50 , 50 a, 76 , 76 a, 76 b ) arranged between said squeezing-diluting-unpacking module ( 4 ) and said at least one settling module ( 30 , 30 a ), within said at least one settling module ( 30 , 30 a ), or downstream of said at least one settling module ( 30 , 30 a );

a control valve ( 74 ) configured to meter the dilution fluid ( 10 ) input to squeezing-diluting-unpacking module ( 4 ); and

a controller ( 75 ) configured to receive an output signal from the dry-matter content sensor ( 50 , 50 a, 76 , 76 a, 76 b ) and to provide a control signal input to control valve ( 74 ) so as to control the dry matter content of the comparatively dirty and comparatively liquid slurry ( 26 ) or of the comparatively refined slurry ( 42 ), according to where the sensor ( 50 , 50 a, 76 , 76 a, 76 b ) is arranged, to match a set-point.

3 . The apparatus ( 2 ) of claim 2 , wherein said controller ( 75 ) is a P.I.D. controller.

4 . The apparatus ( 2 ) of claim 1 , wherein the comparatively dirty and comparatively liquid slurry ( 26 ) has a dry matter content in the range of about 4-6%, and the comparatively dewatered slurry ( 72 ) has a dry matter content in the range of about 10-20%.

5 . The apparatus ( 2 ) of claim 1 , wherein the settling module ( 30 ) includes an elongate basin ( 31 ), the basin including at least one chamber ( 32 , 32 a ), a worm screw ( 34 , 34 a ) extending on the bottom thereof and a motor operable to drive rotation of the worm screw ( 34 ) at a comparatively low speed for collecting the inerts that sediment from the comparatively dirty slurry ( 26 ).

6 . The apparatus ( 2 ) of claim 5 , wherein the bottom portion of the elongate basin ( 31 ) of the settling module ( 30 ) is divided into at least two chambers ( 32 , 32 a ), each chamber having tapered walls ( 33 , 33 a ), and the worm screw ( 34 , 34 a ) is a first worm screw extending on the bottom of one respective chamber ( 32 , 32 a ) and one or more other worm screws ( 34 . 34 a ) respectively extend on the bottom of the other respective ones of the chambers ( 32 , 32 a ).

7 . The apparatus ( 2 ) of claim 1 , wherein the squeezing-diluting-unpacking module ( 4 ) includes an upwardly conveying worm screw ( 5 ) rotating at a comparatively high speed within a cylindrical filter ( 6 ) enclosed by a nozzled manifold ( 9 ) for inletting the dilution fluid ( 10 ).

8 . The apparatus ( 2 ) of claim 1 , wherein the thickening/dewatering module ( 60 ) includes a solid separator ( 61 ) that includes a case ( 62 ) under pressure, a fine filter ( 63 ) and a coaxially inner worm screw ( 64 ) being arranged in case ( 62 ), the inner worm screw ( 64 ) rotating at a comparatively low speed.

9 . The apparatus ( 2 ) of claim 1 , wherein said squeezing-diluting-unpacking module ( 4 ), said at least one settling module ( 30 , 30 a ), and said thickener/dewatering module ( 60 ) are all included in a single structure, forming one and the same machine.

10 . The apparatus ( 2 ) of claim 9 , wherein the structure of said machine is formed from plural frames assembled together, wherein each of said squeezing-diluting-unpacking module ( 4 ), said at least one settling module ( 30 , 30 a ), and said thickener/dewatering module ( 60 ) has such a size as to allow shipment with a standard shipping container, or wherein the squeezing-diluting-unpacking module ( 4 ) and the settling module ( 30 ) together have such a size as to allow shipment with a standard shipping container.

11 . A plant ( 1 ) for pretreatment of organic waste from the Organic Fraction of Municipal Solid Waste and/or from food industries comprising an apparatus ( 2 ) according to claim 1 , and the anaerobic digester ( 90 ) downstream thereof.

12 . The plant ( 1 ) of claim 11 , further comprising a solid separator ( 94 ) downstream of the anaerobic digester ( 90 ), and a waste water treatment plant ( 97 ) downstream of the solid separator ( 94 ), wherein a remaining part of the dilution fluid ( 10 ) input to squeezing-diluting-unpacking module ( 4 ) is provided by liquid collected, but not treated, by the waste water treatment plant ( 97 ).

13 . The plant ( 1 ) of claim 11 , further comprising a buffer unit ( 77 ) arranged between the thickening/dewatering module ( 60 ) and the anaerobic digester ( 90 ), the buffer unit ( 77 ) comprising a tank ( 79 ) storing the comparatively dewatered slurry ( 72 ), and a pump ( 83 ) selectively pumping the comparatively dewatered slurry ( 72 ) through at least one grinder ( 84 , 85 ) to the downstream anaerobic digester ( 90 ).

14 . The plant ( 1 ) of claim 13 wherein the buffer unit ( 77 ) lacks any recirculation of the comparatively dewatered slurry ( 72 ) through a sand trap.

15 . A method for pretreatment of organic waste from the Organic Fraction of Municipal Solid Waste and/or from food industries, upstream of an anaerobic digester, the method comprising:

a) receiving a packaged waste stream,

b) squeezing and diluting the packaged waste stream while unpacking the waste to output a coarser non-digestible stream and a comparatively dirty and comparatively liquid slurry,

c) letting comparatively finer inerts in the comparatively liquid slurry sediment to output a finer inerts stream and a comparatively refined slurry,

d) thickening/dewatering the comparatively refined slurry to output a liquid stream and a comparatively dewatered slurry;

e) delivering the comparatively dewatered slurry to the anaerobic.digester and delivering liquid from the liquid stream for diluting the packaged waste stream in the step b).

16 . The method of claim 15 , further comprising:

measuring a dry matter content of the comparatively dirty and comparatively liquid slurry ( 26 ) or of the comparatively refined slurry ( 42 ); and

metering a dilution fluid of said step b) to control the measured dry matter content to match a set-point, SP.

17 . The method of claim 16 wherein the set-point, SP, corresponds to a dry matter content of less than 6% and the method comprises maintaining the dry matter content of the comparatively dirty and comparatively liquid slurry to be in the range of SP±1%.

18 . The method of claim 16 comprising maintaining the dry matter content of the comparatively dirty and comparatively liquid slurry to be in the range of 4% to 6%.

19 . The method of claim 15 comprising using the liquid stream of the step d) for diluting the packaged waste stream in the step a).

20 . The method of claim 20 comprising digesting the comparatively dewatered slurry, and supplying water output by the digesting for diluting the packaged waste stream in the step b).

21 . The method of claim 15 wherein diluting the packaged waste stream in the step b) comprises adding water to the packaged waste stream in a volume ratio in the range of one part packaged waste stream to five parts water to one part packaged waste stream to ten parts water.

22 . The method of claim 21 wherein diluting the packaged waste stream in the step b) comprises adding water to the packaged waste stream in a volume ratio of about one part packaged waste stream to about eight parts water.

23 . The method of claim 15 wherein the coarser non-digestible stream comprises plastic from plastic bags.