ANDRITZ, one of the market leaders for high-consistency bleach plants, offers the optimum bleaching system for specific needs: from a simple peroxide stage to a three-stage system (including dithionite) for brightness levels above 85% ISO. All bleaching systems include the most efficient washing equipment for providing clean pulp to the paper machine.
Bleaching tower discharge system
The ANDRITZ HC mixer copes with the challenge of mixing a very small amount of chemicals into a large amount of high-consistency pulp. The HC mixer fluffs the pulp to obtain a large surface area and provides optimum conditions for efficient mixing.
The ANDRITZ PHC bleach tower delivers uniform brightness because of the accurate and controlled retention time (first in, first out).
Post-bleach washing results in cleaner pulp to the paper machine (reduction of COD, extractives, anionic trash, turbidity) and thus improves the runability of the paper machine, reduces consumption of wet-end chemicals, and increases the intervals for cleaning of felts, wires, and roll covers. Post-bleach washing also provides an opportunity to separate the water loops of the mechanical pulping system and the paper machine. Recovery of residual peroxide and its re-use in pre-bleaching also offer economic benefits.
