Inert Gas Glovebox - Powder Classifiers
For research and small-scale production applications, PSI has developed safe, integrated inert gas powder classification systems.
Designed, initially, for reactive metal powders where safe handling demands stringent atmosphere control, the classifier applications extends into other sectors including ceramics, food processing & technology and pharmaceuticals.
The PSI systems integrate the four critical elements of a high quality inert gas classifier:
- Powder Transfer
- Powder Handling
- Atmosphere Conditioning
Safe and easy transfer of powder material without loss of atmosphere integrity is enabled via an integral airlock with positive seal & door locking.
A durable, rigid frame with transparent panels and multiple glove ports facilitates high sample visibility, access and handling. Material to be classified is introduced into the air system by a vibrating feeder. From this point it is conveyed to the classifier where, due to the design of the casing and the rotating multi-vane rotor, a spiraling air system is set up. Stainless steel construction of all contact parts ensures the highest cleanliness and safety. As the particles approach the rotor they are subjected to a centrifugal force which may be of several hundred 'g' depending upon the speed of rotation of the rotor and this overcomes or is overcome by the centripetal drag force exerted on the particles by the air as it spirals inwards through the rotor vanes.
The inertial/viscous flow classifier ‘cuts’ powder distributions in the range 1 to 75µm for materials of a range of densities. The cut point is dependent upon the speed of rotation of the classifier rotor and the air flow. Fine, on-stream rotor speed control coupled with an adjustable secondary gas system ensures optimum classification conditions and precise particle size cut points. At the cut point the two opposing forces balance and the fines are conveyed through the rotor to be collected in the fine product cyclone. The coarse particles rejected by the rotor descend where they are flushed by a secondary air system which may liberate any agglomerated fines, and are finally collected in the receiver below the classifier.
An absolute filter series retains ultra-fine particles and eliminates contamination of the glove box when re-circulating the inert gas for economy. Rechargeable catalytic de-gassing and molecular sieve systems reduce oxygen and water to minimal levels and temperature build up is minimised by a heat exchanger.