Alpine AS

The Alpine AS spiral jet mill is designed for the micronization of pharmaceutical powders. Particle sizes as low as a D97 of 2-3 microns can be achieved. The one-piece easy clean design permits ease and thoroughness of cleaning. Other design features available include:

  • Monoblock construction, free of dead spaces and welding seams
  • Vertical mount, for complete drainage during CIP operations
  • Compact design including triclamps for easy access connection sockets for quick assembly and disassembly.
  • Grinding action performed by nozzles integral to the grinding ring, thus avoiding additional protrusions into the grinding zone.

As indicated by the schematic on the left, material is injected into the grinding zone and accelerated by means of an injection gas nozzle. Material flows around the perimeter of the mill wall in a spiral manner. As material passes each additional high pressure gas port it is reduced by particle-to-particle attrition and by impact against the mill wall. As the product is reduced, it becomes lighter in density, and eventually via free vortex centrifugal classification, exits the mill chamber.

The Alpine AS spiral jet mill is available in a variety of designs dependent upon the overall system requirements. These design options include the following:

  • PSR11 (Pressure Shock Resistant) to 10 bar(g)
  • Complete CIP and SIP systems capability.
  • Fabricated housings available in surface finishes as high as 0.2 micron Ra
  • Inert gas operation, either once through nitrogen flow or closed loop operation

Alpine AS spiral jet mills can also be integrated into Stott isolators. This arrangement provides a completely integrated system capable of containment levels as low as 1 microgram/cubic meter.