Apparatus and method to render air bag inflators and other low level detonatable devices inert for recycling

An apparatus for rendering inert detonable devices such as charged air bag inflators for recycling, the apparatus comprising:

• a feeder configured to receive cardboard boxes including a plurality of charged passenger side cylindrical metallic air bag inflators and charged driver side puck shaped metallic air bag inflators, the inflators including ammonium nitrate;
• a shred tower and a cleated inclined conveyor belt with a variable speed drive configured to bring the boxes from the feeder to a top of the shred tower at a controlled feed rate of 20 to 30 seconds per box;
• a first feed hopper at the top of the shred tower;
• a primary shredder disposed within the hopper;
• a rotary feed valve disposed within the hopper and configured to receive the boxes from the conveyor belt and to feed the boxes to the primary shredder for shredding;
• the rotary feed valve configured to close the shredder after receipt of the boxes therein to substantially prevent metallic shards from escaping during said shredding;
• the hopper being closed on all sides and constructed of metallic plate and including a hinged perforated metallic plate cover;
• the hopper including continuous water spray nozzles aimed at shredder teeth to substantially prevent sparking and to wash chemicals from the inflators;
• the primary shredder having relatively widely pitched teeth to tear open the boxes;
• a secondary shredder disposed below the primary shredder and configured to receive the torn boxes and contents therefrom;
• the secondary shredder having relatively finely spaced teeth;
• the hopper including a CCTV camera to view operation remotely, and a UV/IR flame detector connected to a secondary water deluge nozzle to be activated upon detection of a flame;
• a closed chute between the two shredders with a hinged side access door above the secondary shredder to clear jams;
• a water sump of 500 to 1000 gallon capacity disposed below the secondary shredder, and equipped with a high capacity pump feeding to a storage tank;
• a dual inclined auger screw configured to lift solids including metal and cardboard scraps from sump, wherein residual water runs from the solids back to the sump;
• the shredders including pressure sensors configured to stop the units if a jam occurs, to auto-reverse, and then restart shredding x times before signaling an operator of a jam;
• and
• a programmable logic controller (PLC) configured to operate the conveyor belt, the primary and secondary shredders, and the auger screw, and configured to pause operation of components upstream of the jam until cleared;
• the auger screw configured to feed the dewatered metal solids to a rotary reactor incinerator feed pit operating at a minimum 1000 F temperature to destroy any remaining chemical residue and cardboard from box shredding, to leave metal suitable for shipping to metal scrap recyclers;
• wherein the apparatus provides a low speed dual stacked hydraulic shredding operation to open the inflators under a continuous water spray and expose the ammonium nitrate to a water bath to solubilize it and separate it from the metallic components.

A method for rendering inert and separating components of detonable devices fabricated from metal and water soluble chemical explosive propellants, for recycling, the method comprising:

• (a) receiving, with a feeder, material including a plurality of the detonable devices;
• (b) conveying the material in a downstream direction through a shred tower including a hopper, at least one shredder disposed within and/or downstream of the hopper, and a water sump disposed downstream of the at least one shredder;
• (c) feeding, with a first conveyor operatively engaged with the feeder and the shred tower, the material from the feeder to an upstream portion of the hopper at a controlled feed rate;
• (d) selectively actuating a feed valve disposed at the upstream portion of the hopper, between open and closed positions to respectively permit and prevent the material from entering the upstream portion of the hopper;
• (e) irrigating with irrigation means, to substantially prevent sparking and to begin to solubilize and separate chemicals from the metal during operation of the at least one shredder;
• (f) shredding the material with the at least one shredder;
• (g) receiving, in the water sump, the material from the at least one shredder to continue to solubilize and separate the chemicals from the metal;
• (h) lifting, with a second conveyor, solids including shreds of the metal from sump, wherein residual water runs from the solids back to the sump to produce dewatered solids;
• and
• (i) feeding, with the second conveyor, the dewatered solids to a receiving box for metal scrap recycling.