Simulation of control loops of pulp bleaching section using distributed control system – An experimental study

Abstract

Day by day requirement for better quality of paper in terms of brightness and strength is arising. To meet the changing requirements, the bleaching sequences and process conditions need to be modified. For implementing these modified conditions, to increasing the reaction rate and to reduce the chemical wastage control loops need to be redesigned. The process engineer working in the mill must know the design procedure of control loop on DCS. Keeping this in mind, control loop for changing demand of hot water flow used at C/D washer for water spray and temperature of hot water of pulp bleaching section have been designed and simulated offline. Later on these loops were installed, commissioned and tested on-line using DCS (MP 200/1). The results are reported in manual and auto mode of operation.