Centrifugal Impact Mills (Pin Mills)
Grind friable materials, reduce flakes and de-lump agglomerates into narrow particle size ranges without the use of screens
A simple, inexpensive means of grinding, sizing, de-agglomerating and/or homogenizing. Ideal for a broad range of food, chemical, pharmaceutical, nutraceutical, mineral and agricultural products––including pulverizing of insects, eggs and larvae in flour applications––in tight size ranges from coarse to 400 mesh.
Munson's Pin Mill, or "Centrifugal Impact Mill," reduces bulk materials into narrow particle size ranges without the need for screens, hammers, knives or rolls.
Instead, it relies on material impacting hundreds of pins thousands of times as it travels from the center to the periphery of the milling chamber.
The chamber consists of an outer stationary (stator) disc containing circular rows of pins that alternate with concentric rows of pins on the inner rotating (runner) disc.
As metered material is gravity fed through the centrally located inlet of the stator disc, centrifugal force created by the high speed runner disc causes particles to alternately impact stationary pins, and pins traveling at speeds from 30 up to 500 mph before reaching the outlet.
To vary the tight range of particle sizes desired, the operator simply adjusts the speed at which the inner disc rotates, from several hundred to more than 5000 rpm depending on mill diameter. This extreme flexibility enables a Munson Pin Mill, with no modifications, to grind friable materials into tight size ranges from coarse particles down to powders of 400 mesh, and to de-lump agglomerated material.
Materials remain cooler than in other types of mills since retention is minimal and air is constantly drawn through the mill chamber.
The Munson Pin Mill features smooth interior surfaces with none of the crevices associated with screens, hammers, knives or rolls, and vertically-oriented outer discs with hinges for greater interior access than horizontal mill housings, allowing total gravity discharge/draining and rapid cleaning/sanitizing.
It is also compact and economical relative to its high capacity, and is virtually maintenance-free.
Available in carbon steel, and stainless steel to industrial or sanitary/pharmaceutical standards, it is offered with discs in diameters of 8, 18, 24 and 34 in. (203, 457, 610 and 864 mm) and motors from 5 to 125 hp (4 to 93 kw) to process <.25 to 5 ft3 (<7 to 143 liters) of material per minute, depending on application.