The Study And Application Of Inhibitor And Biocide For Chilling Water Treatment

The stable-running of plant was effected by the corrosion problem of chilling water system of AFCP for a long time. Due to the bad corrosion control, include microbe problem, the water chemical items as iron, turbidity and MB always exceeded, result to the heat exchange efficiency of the key HE and polymerize-kettle decreasing. To resolve these problem and ensure the safe, stable, long term running of the plant, it's necessary to filter suitable complex chemical and do some improvement.According to investigated data and actual situation on site and combined with chilling water system characteristic and existing problem, to design the complex. The main corrosion inhibitor complex is molybdate and tungstate. The biocide includes isothiazolin-one, glutara and DBNPA.Lab static-state corrosion experiment, filter the corrosion inhibitor and ensure the dosage and service guideline.Lab sterilization experiment, filter the biocide and ensure the dosage.Manufacture application, validate the biocide and the inhibitor.Adjusting dosage, to assess the ratio of quality and cost integrated.Assessing method:Coupon Weight-losing method as corrosion assessing, and using EASICULT slide to assess the biocide.Other improvement method:New process operation criterion and demand were advanced. Controlling system pH to avoiding the Al corrosion. Adding a set of filter system to solve the turbidity.Through lab experiments, make sure the iso+DBNPA as the biocide, TTA as the copper inhibitor, and Mo-NO2 complex as carbon steel/Al corrosion inhibitor.Based on the lab result, using iso+DBNPA as biocide to control MB is more effective, the count of MB was less than 100cfu/ml. Pass through adjusting chemicals and increasing dosage, the corrosion and turbidity problem of system were resolved, and the carbon corrosion ratio was less than 0.025mm/a, turbidity was less than 20NTU, and iron was less than 1.0mg/l.Through lab experiment, manufacture application and improvement on site, proved, it's feasible to solved existing problems by selected biocide and inhibitor complex.