Sealed rotary feeder

A sealed rotary feeder, comprising

• a casing having an inner cylindrical surface and a chip inlet on one side of said casing and a chip outlet on another side of said casing,
• a rotor installed for rotation in said casing within said cylindrical surface,
• a plurality of channels radially formed around said rotor, a blade movably inserted into each of said plurality of channels, said blades and channels dividing said rotor into plural baskets,
• a clearance provided in each channel between said channel and its respective blade,
• at least one spring positioned in each such clearance,
• gas-introducing means for introducing compressed gas to said clearances from the chip inlet or chip outlet at the higher pressure, said compressed gas being introduced to each of said clearances in turn at a first predetermined position of said rotor during its rotation within said casing to increase the pressure on each respective blade during a first predetermined rotational arc of said rotor,
• gas-exhausting means for exhausting said compressed gas from said clearances to the chip inlet or chip outlet at the lower pressure, said compressed gas being exhausted from each of said clearances in turn at a second predetermined position of said rotor during its rotation within said casing to remove the increased pressure on each respective blade during a second predetermined rotational arc of said rotor.