Rotary Air Classifier Mills
The British Rema Classifier Mill (or “CLM series) is a fixed beater impact grinder embodying two-stage grinding with integral, inter-stage classification. Its design provides two distinct grinding sections, one for raw feed and the other for semi-ground material returned by the classifier requiring a higher grinding intensity for efficient reduction. This feature provides improved grinding efficiency overcoming the limitations of conventional units in which both feed and oversize returns are ground in a single operation.
Features
• Integral forced vortex classifier provides accurate control of product size with sharp cut-off.
• Accurate and consistent product grading.
• On-stream adjustment of the product size by variable speed classifier rotor.
• Controlled generation of superfines.
• Feed via a secondary air inlet gives the ability to pre-classify prior to grinding and minimises over-grinding and the production of superfines.
Operating Principals
• Feed material entering through the inlet duct is introduced to the first stage grinding area.
• Semi-ground product from the first grinding stage passes through circumferential screens in the stator assembly and is conveyed to classifier rotor.
• Particles are classified by the interaction between centripetal and air drag forces within the forced vortex created by the classifier rotor.
• Product size is determined by control of the classifier rotor speed.
• Particles below cut size pass through the classifier rotor and exit with the entraining air through duct.
• Coarse particles above the cut point are rejected by the rotor and directed to the second stage grinding area for further reduction in cross flow configuration and re-cycled through the first stage grinding chamber.
• A secondary air inlet in the casing allows control of the classifier air flow.
• A specially designed exit port (not shown) in the secondary grinding stage enables excess unground impurities to be rejected from the unit during operation.
