Contra Selector Mill Type PPS & PPSR


Gentle pulverizing of dry or moist, soft to medium hard materials. Cool grinding at high throughput capacities with narrow particle size distribution.

Method of Operation

Material must be metered into the machine. Inside the grinding chamber an impeller accelerates the material and throws it against a rotating screen basket. Due to high impact and sheering forces created by the differential speed between impeller and screen basket the material is reduced in size.

The main feature of the Contra Selector Mill is the rotating screen basket. When rotating, centrifugal forces keep the screen free from clogging. Due to the rotation the total screen area is engaged in the grinding process.

Particle size of the end product can be adjusted in a very wide range by changing the speeds of the impeller and screen basket, by the screen size and the number and shape of grinding elements installed.

A rotating scraper keeps the inside of the machine housing free from any sticking material. For special applications the machine housing can be water-cooled or steam jacketed.




Advantages & Features

  • One pass size reduction step produces the desired final particle size
  • Cool grinding operation; no artificial coolants are required
  • Continuous operation, no clogging or screen blinding
  • Self cleaning design; scrapers keep inside of machine housing clean
  • Easy adjustment of particle size
  • Hinged front door allows quick access to the grinding chamber
  • Screen basket and impeller can be easily removed from the front
  • Water or steam jackets available for special applications
  • Stainless Steel and gas tight designs available
  • Pressure shock resistant design available up to 10 bar
  • Safety switches for maximum operator safety
  • Steel fabricated design, rugged and reliable
  • Compact space saving design

Excellent for pulverizing medium hard to soft materials

  • Chemicals
  • Pharmaceutical products
  • Food
  • Spices (Under ambient temperature)
  • Bone and fish meal
  • Press Cakes
  • Detergents
  • Pigments
  • Cellulose ether and derivates

Type PPS 4-120 6-180 8-240 10-300 12-360 14-420
Scale-up Factor f 0.4 1.0 1.7 2.7 4.0 5.2
Rotor Diameter mm 400 600 800 1000 1200 1400
Width of screen mm 120 180 240 300 360 420
Motor, Impeller kW 15-22 30-55 55-110 110-160 160-250 200-315
Motor, Screen kW 7.5-11 15-30 30-55 55-90 90-132 110-160
Machine Weight kg 1750 3300 5250 7650 9750 11500