Systems and methods for processing a heterogeneous waste stream

Abstract

Systems and methods for processing and sorting a municipal solid waste stream are described herein. A system can include a processing sub-system configured to receive a municipal solid waste stream and to remove the non-processable waste, a processing apparatus configured and disposed to receive constituents of the municipal solid waste stream from the processing sub-system and reduce the size of the constituents of the waste stream to an average particle size of less than about ¾ inch, and separators configured to sort the waste stream into constituents based on density.

What is claimed is: 
     
         1 . A system for processing and sorting a municipal solid waste stream, the system comprising:
 a processing sub-system configured to receive a municipal solid waste stream and to remove the non-processable waste;   a processing apparatus configured and disposed to receive constituents of the municipal solid waste stream from the processing sub-system and reduce the size of the constituents of the waste stream to an average particle size of less than about ¾ inch;   a first separator configured and disposed to receive the constituents of the waste stream from the processing apparatus and to separate and remove waste constituents of a first type having a bulk density greater than about 15 lb/ft 3 ; and   a second separator configured and disposed to receive the constituents of the waste stream having a bulk density less than about 15 lb/ft 3  from the first separator and to separate and remove waste constituents of a second type having a bulk density greater than about 4 lb/ft 3 .   
     
     
         2 . The system of  claim 1 , further comprising:
 a third separator configured and disposed to receive the constituents of the waste stream having a bulk density less than about 4 lb/ft 3  from the second separator and to separate and remove waste constituents of a third type having a bulk density greater than about 1 lb/ft 3 .   
     
     
         3 . The system of  claim 1 , wherein the processing sub-system includes a shredder configured to reduce the size of the constituents of the waste stream to be less than about 4 inches. 
     
     
         4 . The system of  claim 3 , wherein the shredder is configured to reduce the size of the constituents of the waste stream to be less than about 1 inch. 
     
     
         5 . The system of  claim 1 , wherein the processing sub-system includes a density separator configured to separate and remove the non-processable waste. 
     
     
         6 . The system of  claim 5 , wherein the density separator is a cyclone separator. 
     
     
         7 . The system of  claim 5 , wherein the density separator is a fluidized bed separator. 
     
     
         8 . The system of  claim 1 , wherein the processing apparatus is a shredder. 
     
     
         9 . The system of  claim 8 , wherein the shredder is configured to reduce the size of the constituents of the waste stream to be less than about ½ inch. 
     
     
         10 . The system of  claim 9 , wherein the shredder is configured to reduce the size of the constituents of the waste stream to be less than about ⅜ inch. 
     
     
         11 . The system of  claim 10 , wherein the shredder is configured to reduce the size of the constituents of the waste stream to be less than about ¼ inch. 
     
     
         12 . The system of  claim 1 , wherein the first separator is a cyclone separator. 
     
     
         13 . The system of  claim 1 , wherein the first separator is a fluidized bed separator. 
     
     
         14 . The system of  claim 1 , wherein the second separator is a cyclone separator. 
     
     
         15 . The system of  claim 1 , wherein the second separator is a fluidized bed separator. 
     
     
         16 . The system of  claim 1 , wherein the waste constituents of the first type are substantially all hard plastic. 
     
     
         17 . The system of  claim 1 , wherein the waste constituents of the second type are substantially all fiber. 
     
     
         18 . The system of  claim 2 , wherein the waste constituents of the third type are substantially all soft plastic. 
     
     
         19 . A system, comprising:
 a first shredder configured to receive a municipal solid waste stream and reduce the size of constituents of the waste stream to be less than about 4 inches;   a first density separator configured and disposed to receive the shredded waste stream from the first shredder and to separate and remove the non-processable waste;   a second shredder configured and disposed to receive the processable waste from the first density separator and to reduce the size of constituents of the processable waste to be less than about ½ inch;   a second density separator configured and disposed to receive the processable waste from the second shredder and to separate and remove the hard plastic material; and   a third density separator configured and disposed to receive the non-hard plastic material from the second density separator and to separate and remove the fiber material.   
     
     
         20 . The system of  claim 19 , further comprising:
 a fourth density separator configured and disposed to receive the non-fiber material from the third density separator and to separate and remove the soft plastic material.   
     
     
         21 .- 40 . (canceled)