Aero GRAVITY TRAP used for removes almost all impurities whih heavier than tufts regardless of its material composition. Gravity Trap can be fitted into any duct with a constant Air-Current. No moving parts , Individually adjustale mote knives and steel segments  at a foot of 'U'turn deflect the heavier particles into a large collection chamber. Maintanance free and does not need electric power. Collecting 0.3 to 0.6%heavy particles practically proven in Textile mills