Rotary Brown Stock Pulp Washers through Mathematical Models: A Review

Abstract

Increasing the accuracy of a model generally increases cost and decreases flexibility. The goal in creating a model is usually to obtain a Sufficiently accurate and flexible model at a low cost. Pulp and Paper making process involves many complex unit operations and process. The process of pulping and paper making is intensive with respect to row materials, energy, water and chemicals. If the plants are heat operated carefully it can also become pollution intensive. The key operation influencing the economy of the plant as well as controlling the pollution load is the washing process. Almost all the mills in the country use rotary vacuum washers for separating the black liquor from the pulp and for ensuring clean pulp to be available for downstream processing. The parameters which influence the operation of a brown stock washer are many and the phenomenon involved in the washing operation are complex. The present paper makes an attempt to look at the various parameters influencing the washing and look at various mathematical models used to predict the washer performance.

Keywords: accuracy, flexibility, low cost, pulp washing, black liquor.