AFG Fluidised Bed Opposed Jet Mill
The iconic Alpine Fluidised Bed Opposed Jet Mill with an integrated classifier is a type of impact mill which permits the contamination-free grinding of even very hard materials down to ultra-high fineness.
In jet milling, comminution is the result of inter-particle collision in the gas jets. Because there are no moving machine parts in the grinding zone, neither machine wear nor product contamination occurs. Therefore, jet milling is often used when contamination-free products are required.
Jet milling is suitable for any material hardness value, from Mohs hardness 1 (talc) to Mohs hardness 10 (diamonds). Typically, the AFG Fluidised Bed Opposed Jet Mill is used for manufacturing powders with a steep particle size distribution and sharp top size limitation in the range < 5 µm to 200 µm.
Jet mills are impact mills which are used to achieve maximum fineness values at maximum product purity. Such particle sizes can only be obtained in connection with an air classifying step. Spiral jet mills have a static air classifier integrated into the mill housing, whereas fluidised bed opposed jet mills are equipped with a dynamic deflector-wheel classifier, giving far greater control of product fineness.
Even fineness products can be processed efficiently with the AFG jet mills.
- Heat-sensitive materials such as toner, resin, wax, fat, ion exchangers, plant protectors, dyestuffs and pigments
- Hard and abrasive materials such as silicon carbide, zircon sand, corundum, glass frits, aluminium oxide, metallic compounds
- Highly pure materials where the requirement is contamination-free processing such as fluorescent powders, silica gel, silica, special metals, ceramic raw materials, pharmaceuticals
- High-performance magnetic materials based on rare earth metals such as neodymium-iron-boron and samarium-cobalt. Mineral raw materials such as kaolin, graphite, mica, talc
- Selectively ground composite materials such as metal alloys
- Single-/multi-wheel classifier head
- Monobloc ceramic classifying wheels ensure minimum wear when processing abrasive products
- Lining: PU, ceramic or special-grade steel to suit the product
- Stainless steel or mild steel, Ni alloy.
- Horizontal or 3D nozzle arrangement, Megajet nozzles
- Selective milling, semi-batch mode, automatic quality control for high quality
- Load cells for product level control
- Material feed via a feed metering system into the classifier head or direct into the milling chamber, or injector feed
- Explosion-pressure-shock-proof to 10 bar (g) with type test certificate as defined in 94/9/EC
- Pharma design up to machine size 630/1 AFG, steep particle size distribution, high bioavailability for active substances, minimum off-spec batches, low manpower requirement
- Hot-gas mode for mineral products permits cost-effective manufacture of large amounts of ultrafine mineral powders
- Circuit-gas systems for pyrophoric products provide maximum safety