Coarse screening and Cleaning system - Process Info

The coarse screening consistes of a primary coarse screen (inject consistency 3,4%), a Combisorter and a secondary coarse screen (inject consistency 1,0%). 

The primary coarse screen cylinder will have 1,1 mm holes. The reject from the primary coarse screen will go to the Combisorter. The Combisorter is a combined screen with a screen plate and two upper screen baskets. This unit gives three types of reject two of which go to the reject handling system. The third reject will be recirculated. From the Combisorter accept will be diluted and pumped to the secondary coarse screen. 

Accept from the primary coarse screen and the secondary coarse screen are brought forward to the Cleaner Mix Tank. 

From the Cleaner Mix Tank the pulp will be pumped through a 3 stage cascade cleaner system (inject consistencies 1,5; 1,0 and 0,6% respectively). Some 10% of the 1st stage accept is recirculated in order to maintain a constant flow through the cleaner system.

Reject from the 3rd stage cleaner will go to the reject handling system.