Spiral jet mill AEROPLEX AS

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Spiral jet mills are frequently used in the pharmaceuticals industry and also for the manufacture of fine-grade chemicals. Because the Aeroplex spiral jet mills AS have no rotating components, there are consequently no bearings and shaft seals, and thus no lubricants are used. Contamination from these sources is therefore impossible. The simple geometry of the mill components makes them easy to clean and also permits sterilisation of the entire mill. Spiral jet mill for the superfine comminution of soft materials (to about Mohs' hardness 3) which display brittle-crystalline fracture behaviour in the fineness range of 10 to 150 µm Design (figure): flat-cylindrical grinding chamber without rotating elements Top section in hinge-back design for easy opening, closing and removal The grinding air is injected tangentially via Laval nozzles in the nozzle ring into the machine. This causes a spiral jet of air to form in the grinding zone, from which the mill derives its name. A high pressure forms in the mill as a result of the spiral flow of air that can rise to 1 bar overpressure in operation without product. The integrated injector is charged with compressed air which ensures that the product is conveyed into the machine against the overpressure present in the machine. This, however, is associated with a considerable compressed air consumption, which can be as much as 30% of the total grinding air requirement. The feed product circulates close to the nozzle ring and is thus intercepted repeatedly by the air jets exiting the nozzles. Comminution is the result of interparticle collision caused by the particles flowing at different speeds in the nozzle jet.