Pin Mill 

  • Is Suitable for materials up to a Mohs‘ hardness of 3, maximum 0.1% permissible fraction of abrasive components
  • Can handle dry crystalline and brittle feeds
  • Can achieve extremely high end-product fineness values
  • With one rotating disk can achieve a final average particle size of less than 50 microns
  • In counter rotation may need cryogenic cooling
  • Is suitable for drug and food applications
  • Has relatively low energy consumption

PAXAA Pin Mills combine simple design and dependability, applying centrifugal force to generate the energy for impact. These mills allow uniform size reduction, greater energy-efficiency, less wear and tear of equipment, along with these distinct features:
  • Free impact, no attrition
  • No screen to clog
  • High throughput per H.P.
  • Handles liquids or solids
  • Simple construction
  • Easy to clean
  • Blow-through capability
  • Low temperature rise
  • Compact installation dimensions

The feed flows from a volumetric feeder by gravity through the PAXAA Pin Mill's inlet, which directs the feed into the grinding chamber's center. The grinding tool (pin disk) rotates at high speed, creating centrifugal force that accelerates the feed particles out to the periphery of the rotor plate. The particles’ high-speed outward flow hurls them against the pins at the tool's periphery. In this zone, the material is subjected to multiple impacts as it passes through the maze of pins or blocks which results in size reduction, or high-intensity mixing. The force imparted to the material is controlled by the speed of the rotor. For maximum energy, the rotor speed would be high; for more gentle handling, low rotational speeds are selected. With disc grinding tools, desired-size particles exit the disc periphery and flow toward the mill's bottom outlet. After exiting the mill, the particles fall by gravity or are drawn by a pneumatic conveying system to downstream processing or storage.

At the “heart” of the PAXAA Pin Mill is the rotor to which the pins or blocks are affixed. Factors affecting performance of the PAXAA Pin Mill include:
  • Rotational speed, which directly relates to tip speed
  • Diameter, which also affects tip speed and therefore impacts energy
  • The number and orientation of pins or blocks
The intermeshing pin design subjects material for size reduction to multiple shattering blows as material negotiates the maze of pins. The block rotor reduces the number of blows, but creates high-exit velocity for shattering materials against the impact wall liner.
For mixing, the speed of the rotor may be reduced, and a smooth impact wall liner employed to avoid product degradation, while creating sufficient turbulence to produce a homogeneous blend. In this way, controlled energy is directly and efficiently applied to the product.

Optimum milling solutions begin with choosing the right mill. Selecting the right mill involves careful consideration of the application parameters and the various mill types available with particular attention to all the wear part options.
In selecting a mill for a specific application four key factors should be considers:
  • initial capital investment
  • internal wear part needs
  • millingduration time requirements
  • power consumption
The PAXAA Pin Mill is a choice thathits all four key factors optimally.Importantly, the PAXAA Pin Mill offers a relatively low capital cost. PAXAA Pin Mills can easily be fitted with fullyinterchangeable and replaceable wearparts with surfaces hardened to 60RC. Also, thePAXAA Pin Mill grinds very quickly as a once throughoperation. Its energy consumption (2 to 5 kWh/ tdepending upon application) is easily justified if milling a medium-valuematerial. Generally, a PAXAA Pin Mill is asensible choice in applications with a 5 to 8 percent silica content, and withmaximum wear protection installed. More...