are controlled by an electronic control unit 25 fig3 shows that each of the fan jet nozzles 12 is constructed in the form of a nozzle head 14 attached to the nozzle bar 11 each fan jet nozzle 12 includes an outer fan jet nozzle channel 15 which has a substantially annular cross section and an inner core jet nozzle channel 16 which is surrounded by the fan jet nozzle channel 15 the outer fan jet nozzle channel 15 is connected to the first blown air generator 21 through a supportive air line 17 the core jet nozzle channel 16 is connected to the second blown air generator 22 through a powdered air line 18 the supportive air line 17 and the powdered air line 18 are formed of air channels formed in the nozzle bar 11 and of hose or tube lines connected to the nozzle bar 11 the outer fan jet nozzle channel 15 emits a supportive air fan jet 19 from its opening and the core jet nozzle channel 16 emits a powdered air core jet 20 from its opening in a non illustrated modified embodiment the fan jet nozzle configuration is formed of a row of core jet nozzle channels that is disposed between an upstream row of fan jet nozzle channels and a downstream row of fan jet nozzle channels as viewed in the direction of sheet travel the core jet nozzle channels emit powdered air core jets which are locked in between two blown air curtains emitted.