The aim to install Brown Stock Washing System is to wash the pulp after the cooking process to recover the chemicals & other organic compounds. The washing system runs on the Counter-Current washing system, where the hot water is used on the final washer and the black liquor is sent to the Recovery section from the First washer. The washers are designed to work on Barometric Leg Vaccum System.

The inlet consistency of the washer is generally 1.5-2.5% and the discharge consistency is around 10%. Shredder Repulper is installed at the inlet of the next washer to make a homogeneous mixture of 1.5- 2% consistency by using the filtrate of the previous washer.

The Filtrate from each washer is collected into the Filtrate Tank & is used in the previous washer for the Dilution purpose. As the liquor is very dilute in nature, there is a tendency for Foam Generation, which is controlled by installing Foam Breaker on a Foam Tank.