INPROSYS Air classifiers

INTRODUCTION

Classification efficiency is critically important for nearly every grinding circuit application.  Increasing classification efficiency can reduce energy consumption in the grinding circuit as well as increase the production capacity.

The INPROSYS air classifiers were designed to provide very high classification efficiency. With seven models, the fineness of the classified product can range from d₉₇ = 3 microns  to 250 microns. Capacities can range from 200 kg/h (440 lbs./h) up to 75 metric TPH (82.5 STPH).

The separation of powders which may have physical properties that cause problems in other classifiers is one of the advantages in the INPROSYS air classifier. In addition, the special design of the air classifier results in a very low pressure drop.   Air classifier testing facilities are available in USA and Europe

 

OPERATING PRINCIPLE

The feed material enters the classifier suspended in air through a vertical pipe positioned at the bottom of the classifier. The initial classification takes place in the classifying chamber.  After passing the feed dispersion cone, the coarse material is discharged from the classifier by gravitation through the coarse fraction outlet.   Remaining material rises to the top of the classifier.

A rotor accelerates the material to its peripheral speed thus creating a centrifugal force in the particle to act against the air drag forces.  As the particles move towards the inside of the rotor and accelerated to its peripheral velocity, a Coriolis effect is generated. As particle velocity increases, the centrifugal force increases and particles can be rejected outside the rotor.  The fine fraction is discharged from the classifier and is recovered from the air in a cyclone and filter.   Filtered air then passes through a blower and is exhausted into the atmosphere.

A secondary air inlet, supplying the classifier with an additional air stream, is used to clean the coarse fraction from the very fine particles agglomerated on a surface of coarser grains. Hence, the classification efficiency is improved.

Key Benefits

• Specially designed rotor produces extremely fine cut  (d₉₇ = 3 microns )
• More consistent performance with "difficult " particles (an elongated or flat shape that often respond inconsistently to opposing forces within the classifier).
• Higher classification efficiency thereby increasing production of the grinding circuit.
• Better control of top size particles
• Lower pressure losses resulting in lower energy consumption resulting in lower operating costs.
• Rotor speeds are 25-50 % slower than the competition, thereby reducing wear and  maintenance cost.