TUpH® pH Sensors And Online Diagnostics Improve Pulp Mill Profitability

This pulp mill produces 700 tpd of bleached softwood pulp. A major part of the pulp cost is the bleaching chemicals themselves, and treatment of wastewater from the bleach plant. Bleaching is achieved using multiple stages that have different objectives with different operating conditions. pH is an important control variable in this area, but measurement in high consistency pulp in the presence of oxidizing agents like ClO2 can be inaccurate and require excessive maintenance. When the pH reading is not available (or uncertain), excessive chemical must be used to ensure desired brightness specifications.