Air Separator Principle , Construction , Advantages

Air Separator :

Mechanical air separator is also known as mechanical air separator , Mechanical air classifiers or dispersion separator .

Air classifier can only used for dry processing  .

they are normally employed when the particle size that is needed to separate is too fine to screen .

Principle :

Air Separator involves balancing of centrifugal force drag force collision and gravity to generate a high precision method of classifying particles according to size and density .

When particles begin in a state  of free fall are exposed to an ascending air current , the force of gravity will dominate over the effect of the air current as the particle dimensions increases .

On the other hand a properly adjusted air current will oppose the force of gravity and lift up the finest mass particles  .

For dry material of 100 mesh , lighter and smaller particles are removed by the airflow while heavier and large particles are not entertained in the airflow .

Construction :

1. It has a single shaft that controls three rotating elements

    - the  feed distribution plate 

    - secondary fan

    - Primary fan

2. The Conical vessels has a separating zone , fines cone and tailing cone .

Working  :

1. in a pneumatic feed process , particles enter the air classifier at a much higher velocity than gravity fed particles  .

2. Feed passed through the hollow feed inlet and drops by gravity to the distribution plate .

3. the Distribution plate disperses the feed material into the separating zone  .

4. the main fan creates a continuous circulating air current into which the distribution plate dispersed the separator feed  .

5. Material leaving the distribution plate are acted upon three forces  :

    - the centrifugal force

    - the force of the ascending air current

    - the force of gravity

6. Havier and large particles thrown out to the walls by centrifugal force they settle by action of gravity .

7.fine particles up to a certain size are lifted by the upward air currents and passed betweens the primary and secondary fan into fine cone .

8. The separated coarse particles are collected from the tailing discharge where as the fine particles are collected from the fine discharge .

9. Air Velocities volume of air and speed of rotation are important factors in separation .

Advantages :

1. it is excellent for de dusting purpose  .

2. eliminate the blinding and breaking issue of screen .

3.  very suitable for fine particle separation .

Disadvantages :

1. Only used for dry processing  .