An apparatus for purging a space in a processing chamber comprises a source of a purge gas; an inlet portion of a purge ring; an inlet baffle located in the inlet portion and fluidically connected to the source of purge gas; and an exhaust portion of the purge ring. The inlet portion and the exhaust portion define a ring hole space having a 360° periphery. The inlet baffle preferably surrounds not less than 180° of said periphery. The inlet baffle is operable to convey purge gas into the ring hole space. The exhaust portion is operable to convey purge gas and other matter out of the ring hole space. Cleaning of the purge ring and other structures in a processing chamber is conducted by flowing a cleaning gas through the inlet baffle. Some embodiments include a gas inlet plenum and an exhaust channel but not a purge ring.