Dissimilar materials sorting process, system and apparata

Abstract

An automated system for sorting dissimilar materials, and in particular for sorting plastics from other materials and for sorting different types of plastics from one another comprises, depending upon the embodiment, combinations of a sizing mechanism, a friction separation, an air separator, a magnetic separator, a dielectric sensor sortation bed, shaker screening, a ballistic separator, an inductive sensor sortation system and a float/sink tank. The dielectric sensor sortation system may be either analog or digital, depending upon the particular implementation. One or more float/sink tanks can be used, depending upon the embodiment, each with a media of a different specific gravity. The media may be water, or water plus a compound such as calcium chloride. In addition, multiples of the same general type of module can be used for particular configurations. A heavy media system or a sand float process can be used either alternatively or additionally.

1 . A concentrator for sorting recyclable materials into lighter and heavier fractions comprising 
 conveyor supplying a stream of materials, at least some of which are recyclable,    at least one separation module which receives at least a portion of the stream of materials and separates the received materials into a lighter fraction and a heavier fraction by exposing the stream to moving air, whereby at least one of the fraction is diverted from its original direction, and    rollback conveyor for eliminating lightweight or round pieces from at least one of the fractions.    
   
   
       2 . The concentrator of  claim 1  wherein the separation module comprises an air knife.  
   
   
       3 . The concentrator of  claim 1  further including at least one float/sink tank which receives at least one of the fractions and further separates that fraction into subfractions according to a predetermined specific gravity.  
   
   
       4 . The concentrator of  claim 3  wherein the at least one float/sink tank receives the heavier fraction.  
   
   
       5 . The concentrator of  claim 4  wherein the heavier fraction comprises at least wire and metal.  
   
   
       6 . The concentrator of  claim 5  wherein the predetermined specific gravity is on the order of 1.4.  
   
   
       7 . The concentrator of  claim 5  wherein the predetermined specific gravity is on the order of 1.1-2.  
   
   
       8 . The concentrator of  claim 1  further comprising magnet means for separating magnetic materials in the materials stream.  
   
   
       9 . The concentrator of  claim 8  wherein the stream is supplied to the magnet means ahead of the separation module.  
   
   
       10 . The concentrator of  claim 4  further comprising a screening module for eliminating dirt and fine particles from the heavier fraction.  
   
   
       11 . The concentrator of  claim 3  wherein the float/sink tank contains media of the predetermined specific gravity.  
   
   
       12 . The concentrator of  claim 11  wherein the specific gravity of the media is adjusted by adding at least one of a group comprising salt, calcium chloride and magnesium sulphite.  
   
   
       13 . The concentrator of  claim 1  further comprising a heavy media system which receives the heavier fraction and sorts that fraction according to a predetermined specific gravity.  
   
   
       14 . The concentrator of  claim 1  further comprising a sand float system which receives the heavier fraction and sorts that fraction according to a predetermined specific gravity.  
   
   
       15 . The concentrator of  claim 3  wherein the at least one float sink tank comprises two tanks, the first tank having a specific gravity on the order of one, and the second float/sink tank having a specific gravity on the order of 1.4.  
   
   
       16 . A wire recovery system comprising 
 feed apparatus for delivering a stream of materials, a portion of the stream of materials comprising wire,    air separator for separating a fraction of the materials which includes the wire from a fraction of the materials which is substantially less dense than wire,    at least one specific gravity separation module having a specific gravity less than the wire, which receives the fraction of the materials which includes the wire, whereby the fraction of materials which includes the wire is further separated into a first subfraction comprising the wire and a second subfraction comprising materials substantially less dense than wire.    
   
   
       17 . The wire recovery system of  claim 16  further comprising a screening module situated before the specific gravity separation module.  
   
   
       18 . The wire recovery system of  claim 16  wherein the specific gravity separation module comprises at least one of a group comprising a float/sink tank, a heavy media system, or a sand float system.  
   
   
       19 . The wire recovery system of  claim 18  wherein the specific gravity of the sand float system is adjusted by air injection.  
   
   
       20 . The wire recovery system of  claim 18  wherein the float/sink tank comprises a plurality of float/sink tanks.  
   
   
       21 . The wire recovery system of  claim 20  wherein each of the plurality of float/sink tanks contain media having a different specific gravity.  
   
   
       22 . A materials separation module comprising 
 at least one array of dielectric sensors for detecting pieces of material having a dielectric constant outside a predetermined range,    a feeder for supplying a stream of pieces of material of different dielectric constants into proximity of the at least one array,    a tracking system for identifying and tracking the location of pieces of material identified by the at least one array, and    a diverter which receives input from the tracking system and responds by diverting the identified pieces of material.    
   
   
       23 . The materials separation module of  claim 22  wherein the dielectric sensors are one of a group comprising digital sensors and analog sensors.  
   
   
       24 . The materials separation module of  claim 22  further including a mister for increasing the moisture content of absorbent pieces with the material.  
   
   
       25 . The materials separation module of  claim 22  wherein the predetermined range is established by a threshold.  
   
   
       26 . The materials separation module of  claim 22  wherein the predetermined range is above 3.4.  
   
   
       27 . The materials separation module of  claim 22  wherein the predetermined range is below 3.4.  
   
   
       28 . The materials separation module of  claim 22  wherein the range is 1.0-3.5  
   
   
       29 . The materials separation module of  claim 22  wherein the at least one array is a plurality of arrays, and the feeder comprises a plurality of conveyors.  
   
   
       30 . The materials separation module of  claim 29  wherein the plurality of conveyors are cascaded and each conveyor is associated with a sensor array.  
   
   
       31 . The materials separation module of  claim 22  further comprising temperature and humidity controls which maintain substantially constant the temperature and humidity of the at least one array and the materials passing in proximity thereto.  
   
   
       32 . The materials separation module of  claim 22  wherein the at least one array is below the stream of pieces of material.  
   
   
       33 . The materials separation module of  claim 22  wherein the at least one array is above the stream of pieces of material.  
   
   
       34 . A plastic separation module comprising 
 at least one specific gravity separation module for separating materials introduced into the tank according to a predetermined specific gravity,    a first mechanism for removing floating materials from the surface of the module,    a second mechanism for removing sunken materials from the bottom of the module.    
   
   
       35 . The plastic separation module of  claim 34  wherein the first mechanism comprises at least one of a group comprising at least one paddle wheel, a conveyor having paddles thereon, and a water jet.  
   
   
       36 . The plastic separation module of  claim 35  wherein the second mechanism comprises at least one of a group comprising a drag chain, a submerged conveyor, and a screw drive.  
   
   
       37 . The plastic separation module of  claim 34  wherein the at least one specific gravity separation module comprises at least one of a group comprising a float/sink tank, a heavy media system, and a sand float system.  
   
   
       38 . The plastic separation module of  claim 34  wherein the at least one specific gravity separation module comprises a plurality of specific gravity separation modules, each containing media of a different specific gravity.  
   
   
       39 . Apparatus for sorting recyclable wire comprising a tank having therein a media having a specific gravity on the order of 1.4, an inlet for receiving a stream of mixed materials, including wire, wherein the wire has a specific gravity which causes the wire to sink in the tank, whereas substantially all of the remaining materials float, a mechanism for removing the materials that sink from the bottom of the tank via a first outlet, and a mechanism for removing the materials that float from the top of the tank via a second outlet.