Battery deconstruction apparatus and methods
Apparatus ( 10 ) for safe and effective shredding of batteries, including lithium-ion batteries, is disclosed. The system integrates a shredding subassembly ( 12 ), an auger/screw conveyor subassembly ( 14 ), a rotary screen subassembly ( 16 ), and an optional solvent recovery/recirculation subassembly ( 18 ). Valves/actuators ( 26, 28 ) can be coordinated such that a nitrogen blanket or a vacuum is maintained within the shredding assembly and/or the other subassemblies ( 16, 18 ). Shredded battery materials are transported to the rotary screen subassembly ( 16 ) via the auger-screw conveyor assembly ( 14 ) before being washed and split into solid and liquid sub-components (FIG. 1 ).
1 . Apparatus for recycling batteries containing solid battery materials and liquid electrolyte, comprising:
a shredder subassembly including a feed hopper having a hopper inlet adapted to receive the batteries, an intermediate hopper connected to said feed hopper via a first valve, a shredding chamber connected to said intermediate hopper via a second valve, and at least one shredder at least partially contained in said shredding chamber and configured to shred the solid battery materials into shredded battery materials;
an auger subassembly adapted to receive shredded battery materials from said shredding chamber of said shredder subassembly;
a rotary screen subassembly, which is adapted to receive the shredded battery materials via said auger subassembly, said rotary screen subassembly comprising a housing having an inlet end proximate to said auger subassembly and an outlet end distal to said auger subassembly, a cylindrical screen, which is adapted for rotation in said housing via a motor, said cylindrical screen including a plurality of holes, a plurality of spiral baffles provided along a length of said cylindrical screen, and a soaking chamber located in said cylindrical screen proximal to said inlet end of said housing; and
a control system, including said first and second valves and a third valve located between said shredder subassembly and said auger subassembly or proximate to said outlet end of said housing of said rotary screen subassembly, said control system being adapted to coordinate operation of said first, second and third valves to create a condition susceptible to the production of a fire-retardant atmosphere in at least said shredding chamber.
2 . The apparatus of claim 1 , wherein said housing is inclined upward such that said outlet end of said housing is higher than said inlet end of said housing.
3 . The apparatus of claim 1 , wherein said auger subassembly includes a motorized screw conveyor.
4 . The apparatus of claim 3 , wherein said motorized screw conveyor is angled upward towards said rotary screen subassembly.
5 . The apparatus of claim 1 , wherein said hopper inlet is formed in an upper end of said feed hopper.
6 . The apparatus of claim 1 , wherein said hopper inlet is formed in a side of said feed hopper.
7 . The apparatus of claim 1 , wherein said motor is located at said inlet end of said housing of said rotary screen subassembly.
8 . The apparatus of claim 1 , wherein said motor is located at said outlet end of said housing of said rotary screen subassembly.
9 . The apparatus of claim 1 , wherein said at least one shredder includes two shredders.
10 . The apparatus of claim 9 , wherein said two shredders include a coarse shredder and a fine shredder.
11 . The apparatus of claim 1 , wherein said third valve is located between said shredder subassembly and said auger subassembly.
12 . The apparatus of claim 1 , wherein said shredder subassembly further comprises a liquid bath in which said least one shredder is immersed.
13 . The apparatus of claim 1 , wherein said third valve is located proximate to said outlet end of said housing of said rotary screen subassembly.
14 . The apparatus of claim 13 , wherein said control system is adapted to maintain a nitrogen blanket or a vacuum between said second valve and said third valve.
15 . The apparatus of claim 1 , wherein said shredder subassembly includes showering means adapted to wash said shredder subassembly with intermittent showers via a series of ports on said shredder subassembly.
16 . The apparatus of claim 1 , wherein said shredder subassembly includes a rotary airlock feeder adapted to control discharge of the shredded battery materials from said at least one shredder.
17 . The apparatus of claim 1 , wherein said at least one shredder is configured to work under vacuum, under N 2 or CO 2 blanketing, and while either completely submerged or subject to intermittent liquid showers.
18 . The apparatus of claim 1 , wherein said first and second valves are gate valves.
19 . The apparatus of claim 1 , wherein said rotary screen subassembly includes an oxygen sensing system, adapted and positioned to monitor an oxygen concentration in said apparatus and configured to shut down said apparatus when excessive oxygen is detected.
20 . A method for recycling batteries containing solid battery materials and liquid electrolyte, said method comprising the steps of:
a) providing an apparatus which includes a shredder subassembly including a feed hopper having a hopper inlet, an intermediate hopper connected to said feed hopper via a first valve, a shredding chamber connected to said intermediate hopper via a second valve, and at least one shredder at least partially contained in said shredding chamber; an auger subassembly in communication with said shredding chamber of said shredder subassembly; and a rotary screen subassembly in communication with said auger subassembly, said rotary screen subassembly including a housing having an inlet end proximate to said auger subassembly and an outlet end distal to said auger subassembly, a cylindrical screen, which is adapted for rotation in said housing via a motor, said cylindrical screen including a plurality of holes, a plurality of spiral baffles provided along a length of said cylindrical screen, and a soaking chamber located in said cylindrical screen proximal to said inlet end of said housing;
b) providing a third valve between said shredder subassembly and said auger subassembly or proximate to said outlet end of said housing of said rotary screen subassembly;
c) delivering batteries to be shredded to said feed hopper via said hopper inlet;
d) conveying the batteries from said feed hopper to said intermediate hopper via said first valve;
e) transferring the batteries from said intermediate hopper to said shredder subassembly via said second valve;
f) shredding the batteries in said shredder subassembly using said at least one shredder to thereby produce shredded batteries;
g) operating said auger subassembly to deliver the shredded batteries from said shredder subassembly to said inlet end of said housing of said rotary screen subassembly;
h) rotating said cylindrical screen of said rotary screen subassembly via said motor to thereby transport at least some of the shredded batteries from said inlet end of said housing of said rotary screen subassembly to said outlet end of said housing of said rotary screen subassembly via said plurality of spiral baffles of said cylindrical screen;
i) washing the shredded batteries in said housing of said rotary screen subassembly by spraying the shredded batteries with a solvent;
j) discharging the shredded batteries from said outlet end of said housing of said rotary screen subassembly; and
k) controlling said first, second and third valves by coordinating their operation to create a condition susceptible to the production of a fire-retardant atmosphere in at least said shredding chamber during the performance of step f).
21 . The method of claim 20 , wherein during the performance of step i) smaller solids of the shredded batteries are separated via a vortex flow created by said spiral baffles of said cylindrical screen.
22 . The method of claim 20 , further comprising the step of directing excess liquid, including a liquid component of the shredded batteries and the solvent, into said soaking chamber of said rotary screen subassembly.
23 . The method of claim 22 , further comprising the steps of continuously discharging liquid from said soaking chamber through holes in said soaking chamber and ejecting a waste stream from a waste drain located below said soaking chamber.
24 . The method of claim 23 , further comprising the step of separating solids from the waste stream to form a solvent stream and separated solids.
25 . The method of claim 24 , further comprising the step of recycling the solvent stream to form at least a portion of the solvent used in the performance of step i).
26 . The method of claim 24 , further comprising the step of drying the separated solids.
27 . The apparatus of claim 1 , wherein said rotary screen subassembly further comprises a plurality of spray nozzles adapted to spray the solvent through said plurality of holes of said cylindrical screen.
28 . The apparatus of claim 1 , further comprising a solvent recovery subassembly, including a collection tank in communication with said rotary screen subassembly, a discharge duct extending from said housing of said rotary screen subassembly to said collection tank, whereby the solvent, the liquid electrolyte and the shredded battery materials can flow from said rotary screen subassembly to said collection tank of said solvent recovery subassembly.
29 . The apparatus of claim 28 , wherein said solvent recovery subassembly includes a pump adapted to transport the solvent from said collection tank to said rotary screen subassembly via a recirculation duct for reuse.
30 . The apparatus of claim 18 , wherein said third valve is a gate valve.
31 . The apparatus of claim 18 , wherein said third valve is a rotary valve.