Patent ID: 7328603

Claim:
A method for collecting residues from mail pieces within a mail facility comprising: providing a plurality of mail pieces to a mail facility in a batch; utilizing two cull conveyors, each of which comprises a smooth conveyor which passes under an overhead counter-rotating drum, to separate said mail pieces in said batch into two groups, the first of said groups comprising thicks and the second of said groups comprising letters and flats, said second group comprising two portions, a first portion on said first cull conveyor and said second portion on said second cull conveyor; transferring said mail pieces in said first portion to a first delayering conveyor which mechanically arranges said mail pieces in said first portion into a generally singular layer; transferring said mail pieces in said second portion to a second delayering conveyor which mechanically arranges said mail pieces in said second portion into a generally singular layer; providing said mail pieces in said first portion to a first chamber and said mail pieces in said second portion to a second chamber, each of said first and said second chambers including an outer shell defining an internal volume, said outer shell having an entrance port for allowing said provided portion to enter said internal volume and an exit port for allowing said provided portion to exit said internal volume, but otherwise substantially sealing said volume, said chamber further including an intake within said outer shell; within each of said chambers, compressing said provided portion a first time; within each of said chambers, compressing said provided portion a second time, at least one of said first and said second compressions aerosolizing a residue present in at least one of said mail pieces in said provided portion; within each of said chambers, flowing air into said intake, said flow into said intake being sufficient to maintain said internal volume at a negative pressure; and transporting said air and said aerosolized residue to a detector capable of detecting the presence of said residue.