How overspray powder been recovered?

1.Powder spray booth
2.Reciprocator for auto spray gun (gun mover)
3.Auto spray gun
4.Powder feed hopper
5.Powder sieve machine
6.Cyclone recovery
7.Cartridge filter recovery
 big cyclone powder coating booth                                  
 Cyclone collectors for overspray powder
The powder that is not deposited onto the objects in  the spray booth (overspray) is not wasted. It is recovered and re-used. This  recovery process is driven by an exhaust air ventilator that provides an   airstream powerful enough to flow through the related extractor equipment such  as a cyclone and filters. The input to the cyclone is connected to the booth  while the output is connected to a suitable exhaust fan. The overspray powder  arrives at the cyclone inlet at a velocity of about 20 metres per second. On  entering the cyclone chamber tangentially the air/powder mixture is given a  rotary motion which creates a centrifugal force on the particles. The larger and heavier particles tend to be ejected to the outside walls of the chamber  and fall to the bottom where they are collected. The lighter fractions will stay suspended in the air stream which on reaching the bottom is deflected by a  conical tail air/powder mix into a rising spiral which is then carried through  the central stack to a filter collector. For a standard powder the recovery  efficiency can be as high as 90%. For lines that have a high percentage of  particles in the recovered powder the recovery efficiency will be reduced (as  low as 75%). Inevitably therefore a cartridge filter is used in conjunction  with a cyclone solely to prevent discharge of the fine powder to the  atmosphere. An additional advantage of cyclone recovery, with particular  reference to colour change, is that due to frictional contact of powder particles,one with another and bounce-back, little or no adherence of powder particles  occurs on the cyclone wall. This means that in many cases only the powder  collection hopper need be thoroughly cleaned between colour changes.