after main motor rotates at full speed, the suspe -nsion is fed into distributor of the outside bowl through the inlet tube. Withthe action of centrifugal force, the suspension is dispersed all over the sieves evenly. The liquid is separated and given off by the clearance of sieves and filter holes of the bowl. The solid stays on the sieves, thus axially moved and finally discharged through the collection channel on front of the second stage bowl.