blower 50 in this manner the fluid is continuously cycled from the blower discharge through the feeder tray 18 collecting enclosure 72 and return duct 80 to prevent the very lightweight chips and turnings and other particles from being carried by the gas stream through the return duct 80 to the suction of the blower where they could damage the blower the return duct 80 inlet aperture 84 preferably is located on the collecting enclosure 72 and away from the effects of the discharging gas stream 54 further a baffle plate 86 is disposed in the trajectory of the blown chips and particles adjacent the connection aperture 84 of the return gas duct 80 thus the very lightweight chips that do not fall downwardly under the influence of gravity and which are instead carried towards the connection aperture 84 will impinge upon the baffle plate 86 and then fall downwardly under the influence of gravity into the separate chip processing path or collecting reservoir in this manner it is seen that the amount of lightweight chips and turnings that may be blown into the return duct 80 is substantially reduced and that the need for a separate screen at the return duct aperture 84 may be eliminated on the other hand if a screen is used at the return duct aperture 84 or elsewhere in.