Patent ID: 7361227

Claim:
An apparatus for coating an article by immersion of the article in a fluidized powder, the apparatus comprising: a container defining an interior and a plate separating the interior into a coating chamber and a plenum, the plate perforated by a plurality of pores to provide for passage of a gas from the plenum to the coating chamber; and a gas supply system connected to the plenum of the container for delivery of a gas to the plenum; the gas supply system comprising two separate supply portions: a) a primary fluidizing portion capable of delivering a gas to the plenum in a quantity sufficient to suspend a powdered material in the coating chamber in a fluidized volume; and b) a controllable pulsating portion capable of providing cyclical pulses of gas, comprising a valve capable of being actuated between opened and closed conditions for respectively enabling and disabling delivery of a controllable supply of gas to the plenum so as to effect a corresponding cyclical variation in the fluidized powder volume, said valve being connected to a controller capable of effecting said actuation between opened and closed conditions in an automatically self-cycling manner to provide the cyclical pulses.