Fixing paper solution in the pulp & paper industry
Process
At the end of the paper machine, the paper is highly absorbent because of its open structure. Various “fixing solutions“ are applied to close the paper‘s pores. Fixer is transferred from IBC's and pumped up to the paper machine where it is applied onto the paper through nozzles. It‘s viscosity varies from 700 to 1500 mPas with a variable solid content between 19 to 43%.
Pumps operate for approximately 18 - 30 hours over a 20 to 25 day production cycle.
Problem
PC pumps were transferring 45 to 50 l/min at 2 bar discharge pressure but experienced repeated dry running damage.
Solution
A hose pump (Verderflex Dura) was installed because it could survive any possible fixer supply interruptions. Previously these resulted in expensive dry running damage such as burnt stators. A Coriolis mass flow meter controls the fixer flow rate by varying the pump speed through a signal to the pump‘s inverter. Additionally, the reversibility of a hose pump greatly simplifies clean down procedures.