Dissolved Content
Process water measurements quantify the mass of soluble carbon compounds present in the drained water of a paper machine or pulp washer. This filtrate organic load accumulates when starches, sizing agents and hemicelluloses dissolve during the repulping and refining stages. The measurement determines the concentration of these substances to prevent subsequent chemical reactions from occurring in the wet end of the machine.
It tracks both the natural hemicelluloses from the wood and the synthetic additives that fail to bind to the paper fibers.
Operational Impact
High concentrations of dissolved organic substances interfere with the performance of retention aids and sizing chemicals. The anionic trash carried in the filtrate neutralizes cationic polymers, which forces operators to increase chemical dosing to achieve the same paper strength. This addition of extra polymers increases production costs and can lead to deposit formation on the forming wire.
Diagnostic Method
Measurement is performed by taking a sample of the drainage water and filtering out the suspended solids to isolate the liquid phase. The remaining solution is analyzed using total organic carbon or chemical oxygen demand methods to establish the precise chemical burden. Standard lab tests are conducted daily to track these levels.
